Kenneth J McLeod - Academia.edu (original) (raw)

Papers by Kenneth J McLeod

Biotechnology Journal, 2007

Gap junctional communication capacity in an orthotopic rat bladder tumor model after intravesical... more Gap junctional communication capacity in an orthotopic rat bladder tumor model after intravesical instillation by gap-FRAP technique. Soumis 09/08.

Journal of Bone and Mineral Research, 2002

The skeleton's sensitivity to mechanical stimuli represents a critical determinant of bone mass a... more The skeleton's sensitivity to mechanical stimuli represents a critical determinant of bone mass and morphology. We have proposed that the extremely low level (<10 microstrain), high frequency (20-50 Hz) mechanical strains, continually present during even subtle activities such as standing are as important to defining the skeleton as the larger strains typically associated with vigorous activity (>2000 microstrain). If these low-level strains are indeed anabolic, then this sensitivity could serve as the basis for a biomechanically based intervention for osteoporosis. To evaluate this hypothesis, the hindlimbs of adult female sheep were stimulated for 20 minutes/day using a noninvasive 0.3g vertical oscillation sufficient to induce approximately 5 microstrain on the cortex of the tibia. After 1 year of stimulation, the physical properties of 10-mm cubes of trabecular bone from the distal femoral condyle of experimental animals (n ‫؍‬ 8) were compared with controls (n ‫؍‬ 9), as evaluated using microcomputed tomography (CT) scanning and materials testing. Bone mineral content (BMC) was 10.6% greater (p < 0.05), and the trabecular number (Tb.N) was 8.3% higher in the experimental animals (p < 0.01), and trabecular spacing decreased by 11.3% (p < 0.01), indicating that bone quantity was increased both by the creation of new trabeculae and the thickening of existing trabeculae. The trabecular bone pattern factor (TBPf) decreased 24.2% (p < 0.03), indicating trabecular morphology adapting from rod shape to plate shape. Significant increases in stiffness and strength were observed in the longitudinal direction (12.1% and 26.7%, respectively; both, p < 0.05), indicating that the adaptation occurred primarily in the plane of weightbearing. These results show that extremely low level mechanical stimuli improve both the quantity and the quality of trabecular bone. That these deformations are several orders of magnitude below those peak strains which arise during vigorous activity indicates that this biomechanically based signal may serve as an effective intervention for osteoporosis. (

Cerebral and Cerebellar Cortex – Interaction and Dynamics in Health and Disease, 2021

Cognitive aging is a progressive condition leading to dementia, a condition which is now the sixt... more Cognitive aging is a progressive condition leading to dementia, a condition which is now the sixth leading cause of death in the U.S., as well as being among the most expensive healthcare conditions to manage. With over 5 million affected in the U.S. alone, the annual costs to the Medicare/Medicaid system exceeds 200billion,andwiththerisingageofthepopulation,annualcostsofdementiacareareexpectedtoexceed200 billion, and with the rising age of the population, annual costs of dementia care are expected to exceed 200billion,andwiththerisingageofthepopulation,annualcostsofdementiacareareexpectedtoexceed500 billion by 2040. As there is no cure for dementia, a consensus has formed that a more pragmatic goal of research should be developing interventions capable of slowing or preventing cognitive aging. We propose that this is a readily achievable goal. Cognitive impairment is closely linked to cerebral perfusion, and cerebral perfusion is a function of cardiac output. In turn, cardiac output is completely dependent on venous return, which in the upright human, relies on adequate soleus muscle activity. As modern adults rarely squat, which is necessary for maintaini...

Journal of Bone and Mineral Research, 2003

A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal... more A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal women demonstrated that brief periods (<20 minutes) of a low-level (0.2g, 30 Hz) vibration applied during quiet standing can effectively inhibit bone loss in the spine and femur, with efficacy increasing significantly with greater compliance, particularly in those subjects with lower body mass. Introduction: Indicative of the anabolic potential of mechanical stimuli, animal models have demonstrated that short periods (Ͻ30 minutes) of low-magnitude vibration (Ͻ0.3g), applied at a relatively high frequency (20-90 Hz), will increase the number and width of trabeculae, as well as enhance stiffness and strength of cancellous bone. Here, a 1-year prospective, randomized, double-blind, and placebo-controlled clinical trial in 70 women, 3-8 years past the menopause, examined the ability of such high-frequency, low-magnitude mechanical signals to inhibit bone loss in the human. Materials and Methods: Each day, one-half of the subjects were exposed to short-duration (two 10-minute treatments/ day), low-magnitude (2.0 m/s 2 peak to peak), 30-Hz vertical accelerations (vibration), whereas the other half stood for the same duration on placebo devices. DXA was used to measure BMD at the spine, hip, and distal radius at baseline, and 3, 6, and 12 months. Fifty-six women completed the 1-year treatment. Results and Conclusions: The detection threshold of the study design failed to show any changes in bone density using an intention-to-treat analysis for either the placebo or treatment group. Regression analysis on the a priori study group demonstrated a significant effect of compliance on efficacy of the intervention, particularly at the lumbar spine (p ϭ 0.004). Posthoc testing was used to assist in identifying various subgroups that may have benefited from this treatment modality. Evaluating those in the highest quartile of compliance (86% compliant), placebo subjects lost 2.13% in the femoral neck over 1 year, whereas treatment was associated with a gain of 0.04%, reflecting a 2.17% relative benefit of treatment (p ϭ 0.06). In the spine, the 1.6% decrease observed over 1 year in the placebo group was reduced to a 0.10% loss in the active group, indicating a 1.5% relative benefit of treatment (p ϭ 0.09). Considering the interdependence of weight, the spine of lighter women (Ͻ65 kg), who were in the highest quartile of compliance, exhibited a relative benefit of active treatment of 3.35% greater BMD over 1 year (p ϭ 0.009); for the mean compliance group, a 2.73% relative benefit in BMD was found (p ϭ 0.02). These preliminary results indicate the potential for a noninvasive, mechanically mediated intervention for osteoporosis. This non-pharmacologic approach represents a physiologically based means of inhibiting the decline in BMD that follows menopause, perhaps most effectively in the spine of lighter women who are in the greatest need of intervention.

Objective Assess treatment superiority of Pulsed Shortwave Therapy (PSWT) against COX-2 NSAID the... more Objective Assess treatment superiority of Pulsed Shortwave Therapy (PSWT) against COX-2 NSAID therapy, in reducing disability and pain due to cervical osteoarthritis.Design 200chronic pain suffers (average pain duration about 2 years)diagnosed with cervical osteoarthritis by radiological imaging were randomized into one of two treatmentarms: COX-2 NSAID treatment: Etoricoxib 60mg/day for 4 weeks; or, PSWT treatmentworn 24 hours/day for 4 weeks. The primary outcome measure was the 4-week score on the Neck Disability Index (NDI): a 10-question assessment on a 50-point scale. Secondary outcome measures included pain(at rest and during activity)measured on a Visual Analog Scale (VAS)of0-100 mm, dose count of rescue pain medication (paracetamol)use and a treatment satisfaction rating. These 4-week scores were compared across the two arms to assess superiority.Results After 4 weeks of treatment,subjects in both study arms reported significantly lower (p<0.0001) 4-week measures (11.24-N...

AJP: Regulatory, Integrative and Comparative Physiology, 2004

Recent studies have indicated that plantar-based vibration may be an effective approach for the p... more Recent studies have indicated that plantar-based vibration may be an effective approach for the prevention and treatment of osteoporosis. We addressed the hypothesis of whether the plantar vibration operated by way of the skeletal muscle pump, resulting in enhanced blood and fluid flow to the lower body. We combined plantar stimulation with upright tilt table testing in 18 women aged 46–63 yr. We used strain-gauge plethysmography to measure calf blood flow, venous capacitance, and the microvascular filtration relation, as well as impedance plethysmography to examine changes in leg, splanchnic, and thoracic blood flow while supine at a 35° upright tilt. A vibrating platform was placed on the footboard of a tilt table, and measurements were made at 0, 15, and 45 Hz with an amplitude of 0.2 g point to point, presented in random order. Impedance-measured supine blood flows were significantly ( P = 0.05) increased in the calf (30%), pelvic (26%), and thoracic regions (20%) by plantar vib...

2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006

Alarmed physiological monitors have become a standard part of the ICU. While the alarms generated... more Alarmed physiological monitors have become a standard part of the ICU. While the alarms generated by these monitors can be important indicators of an altered physiological condition, most are unhelpful to medical staff due to a high incidence of false and clinically insignificant alarms. High numbers of false/insignificant alarms can lead to several adverse consequences such as increased patient anxiety, distraction of clinicians, and decreased efficiency in delivery of care. Furthermore, repeated false/insignificant alarms may increase the chance that healthcare providers ignore clinically significant alarms. In this paper we review the current state of intelligent alarm processing and describe an integrated systems methodology to extract clinically relevant information from physiological data. Such a method would aid significantly in the reduction of false alarms and provide nursing staff with a more reliable indicator of patient condition.

The Quarterly Review of Biology, 1999

More praise for Cats' Paws and Catapults "[Steven Vogel] writes with unusual recognitio... more More praise for Cats' Paws and Catapults "[Steven Vogel] writes with unusual recognition of the needs of the inex- pert reader." —Philip Morrison, Scientific American "Unceasingly, [Vogel] advocates the fun of science." —Peter Gorner, Chicago Tribune "If [D'Arcy] Thompson's work defined ...

Medicine & Science in Sports & Exercise, 2011

Journal of Thermal Biology, 2009

Americans over the last 40 years may have been due to adaptive thermogenesis by calculating the w... more Americans over the last 40 years may have been due to adaptive thermogenesis by calculating the weight gains which would have been required to maintain heat balance due to environmental changes over this time period. 2. Population-weighted degree-cooling-day data and air-condition adoption rates from 1960 to 2002 indicate that the average American in 2002 was living in an environment, that was, on average, 1.4 1C cooler than in 1960. 3. Under these conditions, heat balance would require body mass gains of approximately 11.7 kg in men, and 9.0 kg in women if adaptive thermogenesis were the sole adaptive strategy utilized. 4. Consistency of the model predictions with actual weight gains leads to the suggestion that body mass may primarily reflect an involuntary adaptive response; correspondingly, extensive exposures to indoor cooling may significantly influence obesity prevalence.

Journal of Bone and Mineral Research, 2009

The distribution, expression, and functionality of gap junctions was examined in bovine chondrocy... more The distribution, expression, and functionality of gap junctions was examined in bovine chondrocytes (BCs) isolated from mature articular cartilage. BC cells displayed irnmunoreactivity for connexin 43 (Cx43), a specific gap junction protein. Cx43 protein expression was confirmed by Western blot analysis, and Cx43 mRNA was detected by nuclease protection assay. Additionally, BCs were shown to be functionally coupled, as revealed by dye transfer studies, and octanol, a gap junction uncoupler, greatly attenuated coupling. Furthermore, confocal microscopy of flu03 loaded BC cells revealed that deformation-induced cytosolic CaZ+ ion (Ca2+) signals propagated from cell-to-cell via gap junctions. To our knowledge, this is the first evidence suggesting that chondrocytes isolated from adult articular cartilage express functional gap junctions.

Blood Purification, 2009

Beat-to-beat blood pressure monitoring was used to assess the efficacy of reflex-mediated, calf m... more Beat-to-beat blood pressure monitoring was used to assess the efficacy of reflex-mediated, calf muscle pump stimulation to enhance cardiovascular refilling in subjects in the supine and seated positions, with extension of this stimulation technology to dialysis evaluated in 2 dialysis patients. Micromechanical stimulation (50 mum at 45 Hz) of the plantar surface was found to significantly increase both the rate and volume of cardiovascular refilling relative to that observed for subjects in the supine position. During hemodialysis, calf muscle pump stimulation permitted significantly increased ultrafiltrate removal, specifically from 78 to 96% of clinical goal, while serving to maintain both blood pressure and blood volume.

Journal of Bone Biology and Osteoporosis

Nutrient delivery to bone tissue, as for all tissues in the body, is provided through interstitia... more Nutrient delivery to bone tissue, as for all tissues in the body, is provided through interstitial fluid flow. This flow is driven by the differential fluid pressures between the intramedullary canal and the tissues outside of the bone. Correspondingly, reductions in tissue fluid pressure should enhance interstitial bone fluid flow, nutrient delivery, and thereby increase bone mineral density. This hypothesis was tested in a one year long pilot clinical study of healthy, employed, perimenopausal women (42 - 68 years). Soleus muscle (calf muscle pump) stimulation was utilized with the intent of increasing lower limb fluid return to the heart, serving to both reduce lower limb tissue pressures and to increase intramedullary pressures by increasing cardiac output. Dual-energy x-ray absorptiometry (DXA) assessments of bone mineral density (BMD) were obtained at 12 month intervals. Muscle stimulation usage ranged from 0.7 to 4.8 hours/work-day. Dose dependent responses between duration o...

Clinical interventions in aging, 2017

Cognitive decline in the elderly is strongly associated with cerebral hypoperfusion, a condition ... more Cognitive decline in the elderly is strongly associated with cerebral hypoperfusion, a condition that can be reversed with exercise. Adhering to a traditional exercise regimen, however, is challenging for this population. In a pilot clinical study, we evaluated the ability of a "passive" exercise regimen (noninvasive calf muscle pump stimulation) to normalize blood pressure in a chronically hypotensive elderly population and enhance cognitive function. Ten elderly (82.5±7.5 years) men and women volunteers, residing in a senior living facility in upstate New York, were divided into control (N=5) and intervention (N=5) groups based on initial diastolic blood pressure (DBP); participants with initial DBP <65 mmHg became intervention participants, and those with initial DBP >65 mmHg enrolled in the control group. Body mass, blood pressure, and executive function (using incongruent Stroop and Trailmaking B test) were evaluated weekly for 4 months. At initiation of the stu...

Biotechnology Journal, 2007

Gap junctional communication capacity in an orthotopic rat bladder tumor model after intravesical... more Gap junctional communication capacity in an orthotopic rat bladder tumor model after intravesical instillation by gap-FRAP technique. Soumis 09/08.

Journal of Bone and Mineral Research, 2002

The skeleton's sensitivity to mechanical stimuli represents a critical determinant of bone mass a... more The skeleton's sensitivity to mechanical stimuli represents a critical determinant of bone mass and morphology. We have proposed that the extremely low level (<10 microstrain), high frequency (20-50 Hz) mechanical strains, continually present during even subtle activities such as standing are as important to defining the skeleton as the larger strains typically associated with vigorous activity (>2000 microstrain). If these low-level strains are indeed anabolic, then this sensitivity could serve as the basis for a biomechanically based intervention for osteoporosis. To evaluate this hypothesis, the hindlimbs of adult female sheep were stimulated for 20 minutes/day using a noninvasive 0.3g vertical oscillation sufficient to induce approximately 5 microstrain on the cortex of the tibia. After 1 year of stimulation, the physical properties of 10-mm cubes of trabecular bone from the distal femoral condyle of experimental animals (n ‫؍‬ 8) were compared with controls (n ‫؍‬ 9), as evaluated using microcomputed tomography (CT) scanning and materials testing. Bone mineral content (BMC) was 10.6% greater (p < 0.05), and the trabecular number (Tb.N) was 8.3% higher in the experimental animals (p < 0.01), and trabecular spacing decreased by 11.3% (p < 0.01), indicating that bone quantity was increased both by the creation of new trabeculae and the thickening of existing trabeculae. The trabecular bone pattern factor (TBPf) decreased 24.2% (p < 0.03), indicating trabecular morphology adapting from rod shape to plate shape. Significant increases in stiffness and strength were observed in the longitudinal direction (12.1% and 26.7%, respectively; both, p < 0.05), indicating that the adaptation occurred primarily in the plane of weightbearing. These results show that extremely low level mechanical stimuli improve both the quantity and the quality of trabecular bone. That these deformations are several orders of magnitude below those peak strains which arise during vigorous activity indicates that this biomechanically based signal may serve as an effective intervention for osteoporosis. (

Cerebral and Cerebellar Cortex – Interaction and Dynamics in Health and Disease, 2021

Cognitive aging is a progressive condition leading to dementia, a condition which is now the sixt... more Cognitive aging is a progressive condition leading to dementia, a condition which is now the sixth leading cause of death in the U.S., as well as being among the most expensive healthcare conditions to manage. With over 5 million affected in the U.S. alone, the annual costs to the Medicare/Medicaid system exceeds 200billion,andwiththerisingageofthepopulation,annualcostsofdementiacareareexpectedtoexceed200 billion, and with the rising age of the population, annual costs of dementia care are expected to exceed 200billion,andwiththerisingageofthepopulation,annualcostsofdementiacareareexpectedtoexceed500 billion by 2040. As there is no cure for dementia, a consensus has formed that a more pragmatic goal of research should be developing interventions capable of slowing or preventing cognitive aging. We propose that this is a readily achievable goal. Cognitive impairment is closely linked to cerebral perfusion, and cerebral perfusion is a function of cardiac output. In turn, cardiac output is completely dependent on venous return, which in the upright human, relies on adequate soleus muscle activity. As modern adults rarely squat, which is necessary for maintaini...

Journal of Bone and Mineral Research, 2003

A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal... more A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal women demonstrated that brief periods (<20 minutes) of a low-level (0.2g, 30 Hz) vibration applied during quiet standing can effectively inhibit bone loss in the spine and femur, with efficacy increasing significantly with greater compliance, particularly in those subjects with lower body mass. Introduction: Indicative of the anabolic potential of mechanical stimuli, animal models have demonstrated that short periods (Ͻ30 minutes) of low-magnitude vibration (Ͻ0.3g), applied at a relatively high frequency (20-90 Hz), will increase the number and width of trabeculae, as well as enhance stiffness and strength of cancellous bone. Here, a 1-year prospective, randomized, double-blind, and placebo-controlled clinical trial in 70 women, 3-8 years past the menopause, examined the ability of such high-frequency, low-magnitude mechanical signals to inhibit bone loss in the human. Materials and Methods: Each day, one-half of the subjects were exposed to short-duration (two 10-minute treatments/ day), low-magnitude (2.0 m/s 2 peak to peak), 30-Hz vertical accelerations (vibration), whereas the other half stood for the same duration on placebo devices. DXA was used to measure BMD at the spine, hip, and distal radius at baseline, and 3, 6, and 12 months. Fifty-six women completed the 1-year treatment. Results and Conclusions: The detection threshold of the study design failed to show any changes in bone density using an intention-to-treat analysis for either the placebo or treatment group. Regression analysis on the a priori study group demonstrated a significant effect of compliance on efficacy of the intervention, particularly at the lumbar spine (p ϭ 0.004). Posthoc testing was used to assist in identifying various subgroups that may have benefited from this treatment modality. Evaluating those in the highest quartile of compliance (86% compliant), placebo subjects lost 2.13% in the femoral neck over 1 year, whereas treatment was associated with a gain of 0.04%, reflecting a 2.17% relative benefit of treatment (p ϭ 0.06). In the spine, the 1.6% decrease observed over 1 year in the placebo group was reduced to a 0.10% loss in the active group, indicating a 1.5% relative benefit of treatment (p ϭ 0.09). Considering the interdependence of weight, the spine of lighter women (Ͻ65 kg), who were in the highest quartile of compliance, exhibited a relative benefit of active treatment of 3.35% greater BMD over 1 year (p ϭ 0.009); for the mean compliance group, a 2.73% relative benefit in BMD was found (p ϭ 0.02). These preliminary results indicate the potential for a noninvasive, mechanically mediated intervention for osteoporosis. This non-pharmacologic approach represents a physiologically based means of inhibiting the decline in BMD that follows menopause, perhaps most effectively in the spine of lighter women who are in the greatest need of intervention.

Objective Assess treatment superiority of Pulsed Shortwave Therapy (PSWT) against COX-2 NSAID the... more Objective Assess treatment superiority of Pulsed Shortwave Therapy (PSWT) against COX-2 NSAID therapy, in reducing disability and pain due to cervical osteoarthritis.Design 200chronic pain suffers (average pain duration about 2 years)diagnosed with cervical osteoarthritis by radiological imaging were randomized into one of two treatmentarms: COX-2 NSAID treatment: Etoricoxib 60mg/day for 4 weeks; or, PSWT treatmentworn 24 hours/day for 4 weeks. The primary outcome measure was the 4-week score on the Neck Disability Index (NDI): a 10-question assessment on a 50-point scale. Secondary outcome measures included pain(at rest and during activity)measured on a Visual Analog Scale (VAS)of0-100 mm, dose count of rescue pain medication (paracetamol)use and a treatment satisfaction rating. These 4-week scores were compared across the two arms to assess superiority.Results After 4 weeks of treatment,subjects in both study arms reported significantly lower (p<0.0001) 4-week measures (11.24-N...

AJP: Regulatory, Integrative and Comparative Physiology, 2004

Recent studies have indicated that plantar-based vibration may be an effective approach for the p... more Recent studies have indicated that plantar-based vibration may be an effective approach for the prevention and treatment of osteoporosis. We addressed the hypothesis of whether the plantar vibration operated by way of the skeletal muscle pump, resulting in enhanced blood and fluid flow to the lower body. We combined plantar stimulation with upright tilt table testing in 18 women aged 46–63 yr. We used strain-gauge plethysmography to measure calf blood flow, venous capacitance, and the microvascular filtration relation, as well as impedance plethysmography to examine changes in leg, splanchnic, and thoracic blood flow while supine at a 35° upright tilt. A vibrating platform was placed on the footboard of a tilt table, and measurements were made at 0, 15, and 45 Hz with an amplitude of 0.2 g point to point, presented in random order. Impedance-measured supine blood flows were significantly ( P = 0.05) increased in the calf (30%), pelvic (26%), and thoracic regions (20%) by plantar vib...

2006 International Conference of the IEEE Engineering in Medicine and Biology Society, 2006

Alarmed physiological monitors have become a standard part of the ICU. While the alarms generated... more Alarmed physiological monitors have become a standard part of the ICU. While the alarms generated by these monitors can be important indicators of an altered physiological condition, most are unhelpful to medical staff due to a high incidence of false and clinically insignificant alarms. High numbers of false/insignificant alarms can lead to several adverse consequences such as increased patient anxiety, distraction of clinicians, and decreased efficiency in delivery of care. Furthermore, repeated false/insignificant alarms may increase the chance that healthcare providers ignore clinically significant alarms. In this paper we review the current state of intelligent alarm processing and describe an integrated systems methodology to extract clinically relevant information from physiological data. Such a method would aid significantly in the reduction of false alarms and provide nursing staff with a more reliable indicator of patient condition.

The Quarterly Review of Biology, 1999

More praise for Cats' Paws and Catapults "[Steven Vogel] writes with unusual recognitio... more More praise for Cats' Paws and Catapults "[Steven Vogel] writes with unusual recognition of the needs of the inex- pert reader." —Philip Morrison, Scientific American "Unceasingly, [Vogel] advocates the fun of science." —Peter Gorner, Chicago Tribune "If [D'Arcy] Thompson's work defined ...

Medicine & Science in Sports & Exercise, 2011

Journal of Thermal Biology, 2009

Americans over the last 40 years may have been due to adaptive thermogenesis by calculating the w... more Americans over the last 40 years may have been due to adaptive thermogenesis by calculating the weight gains which would have been required to maintain heat balance due to environmental changes over this time period. 2. Population-weighted degree-cooling-day data and air-condition adoption rates from 1960 to 2002 indicate that the average American in 2002 was living in an environment, that was, on average, 1.4 1C cooler than in 1960. 3. Under these conditions, heat balance would require body mass gains of approximately 11.7 kg in men, and 9.0 kg in women if adaptive thermogenesis were the sole adaptive strategy utilized. 4. Consistency of the model predictions with actual weight gains leads to the suggestion that body mass may primarily reflect an involuntary adaptive response; correspondingly, extensive exposures to indoor cooling may significantly influence obesity prevalence.

Journal of Bone and Mineral Research, 2009

The distribution, expression, and functionality of gap junctions was examined in bovine chondrocy... more The distribution, expression, and functionality of gap junctions was examined in bovine chondrocytes (BCs) isolated from mature articular cartilage. BC cells displayed irnmunoreactivity for connexin 43 (Cx43), a specific gap junction protein. Cx43 protein expression was confirmed by Western blot analysis, and Cx43 mRNA was detected by nuclease protection assay. Additionally, BCs were shown to be functionally coupled, as revealed by dye transfer studies, and octanol, a gap junction uncoupler, greatly attenuated coupling. Furthermore, confocal microscopy of flu03 loaded BC cells revealed that deformation-induced cytosolic CaZ+ ion (Ca2+) signals propagated from cell-to-cell via gap junctions. To our knowledge, this is the first evidence suggesting that chondrocytes isolated from adult articular cartilage express functional gap junctions.

Blood Purification, 2009

Beat-to-beat blood pressure monitoring was used to assess the efficacy of reflex-mediated, calf m... more Beat-to-beat blood pressure monitoring was used to assess the efficacy of reflex-mediated, calf muscle pump stimulation to enhance cardiovascular refilling in subjects in the supine and seated positions, with extension of this stimulation technology to dialysis evaluated in 2 dialysis patients. Micromechanical stimulation (50 mum at 45 Hz) of the plantar surface was found to significantly increase both the rate and volume of cardiovascular refilling relative to that observed for subjects in the supine position. During hemodialysis, calf muscle pump stimulation permitted significantly increased ultrafiltrate removal, specifically from 78 to 96% of clinical goal, while serving to maintain both blood pressure and blood volume.

Journal of Bone Biology and Osteoporosis

Nutrient delivery to bone tissue, as for all tissues in the body, is provided through interstitia... more Nutrient delivery to bone tissue, as for all tissues in the body, is provided through interstitial fluid flow. This flow is driven by the differential fluid pressures between the intramedullary canal and the tissues outside of the bone. Correspondingly, reductions in tissue fluid pressure should enhance interstitial bone fluid flow, nutrient delivery, and thereby increase bone mineral density. This hypothesis was tested in a one year long pilot clinical study of healthy, employed, perimenopausal women (42 - 68 years). Soleus muscle (calf muscle pump) stimulation was utilized with the intent of increasing lower limb fluid return to the heart, serving to both reduce lower limb tissue pressures and to increase intramedullary pressures by increasing cardiac output. Dual-energy x-ray absorptiometry (DXA) assessments of bone mineral density (BMD) were obtained at 12 month intervals. Muscle stimulation usage ranged from 0.7 to 4.8 hours/work-day. Dose dependent responses between duration o...

Clinical interventions in aging, 2017

Cognitive decline in the elderly is strongly associated with cerebral hypoperfusion, a condition ... more Cognitive decline in the elderly is strongly associated with cerebral hypoperfusion, a condition that can be reversed with exercise. Adhering to a traditional exercise regimen, however, is challenging for this population. In a pilot clinical study, we evaluated the ability of a "passive" exercise regimen (noninvasive calf muscle pump stimulation) to normalize blood pressure in a chronically hypotensive elderly population and enhance cognitive function. Ten elderly (82.5±7.5 years) men and women volunteers, residing in a senior living facility in upstate New York, were divided into control (N=5) and intervention (N=5) groups based on initial diastolic blood pressure (DBP); participants with initial DBP <65 mmHg became intervention participants, and those with initial DBP >65 mmHg enrolled in the control group. Body mass, blood pressure, and executive function (using incongruent Stroop and Trailmaking B test) were evaluated weekly for 4 months. At initiation of the stu...