ALi Alzahrani - Academia.edu (original) (raw)

Papers by ALi Alzahrani

Computational and Mathematical Methods in Medicine, 2021

In March 2020, the World Health Organization announced the COVID-19 pandemic, its dangers, and it... more In March 2020, the World Health Organization announced the COVID-19 pandemic, its dangers, and its rapid spread throughout the world. In March 2021, the second wave of the pandemic began with a new strain of COVID-19, which was more dangerous for some countries, including India, recording 400,000 new cases daily and more than 4,000 deaths per day. This pandemic has overloaded the medical sector, especially radiology. Deep-learning techniques have been used to reduce the burden on hospitals and assist physicians for accurate diagnoses. In our study, two models of deep learning, ResNet-50 and AlexNet, were introduced to diagnose X-ray datasets collected from many sources. Each network diagnosed a multiclass (four classes) and a two-class dataset. The images were processed to remove noise, and a data augmentation technique was applied to the minority classes to create a balance between the classes. The features extracted by convolutional neural network (CNN) models were combined with t...

Cureus, 2021

Bin Mosa et al. This is an open access article distributed under the terms of the Creative Common... more Bin Mosa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

International Journal of Surgery Case Reports, 2020

INTRODUCTION: Gastrointestinal basidiobolomycosis (GIB) is an uncommon fungal infection caused by... more INTRODUCTION: Gastrointestinal basidiobolomycosis (GIB) is an uncommon fungal infection caused byBasidiobolus ranarum, with less than 80 cases reported in the literature. PRESENTATION OF CASE: A 36-year-old woman presented with colicky upper abdominal pain for 2 months and inability to pass stool for 2 days. Computed tomography of the abdomen and colonoscopy both showed a mass in the transverse colon. Colonoscopic biopsy suggested a zygomycosis. Laparotomy revealed a perforated mass in the transverse colon; the mass also involved the small bowel and stomach. En bloc resection was performed, and the incision was closed for a second-look procedure. The patient was admitted to the intensive care unit and placed on a ventilator and inotropes; however, her condition deteriorated, and she died on day 24 post admission. The histopathology report (obtained after the patient's death) was consistent with GIB. DISCUSSION: Gastrointestinal basidiobolomycosis presents with nonspecific signs and symptoms and so the diagnosis is easily missed or delayed. Timely, accurate diagnosis is crucially important, especially when there is intestinal obstruction and sepsis. Persistent severe abdominal pain in a patient with neutropenia should alert the physician to the possibility of a fungal infection. There are reports from several countries of basidiobolomycosis in immunocompetent hosts. The disease shows no age predilection, but males may be more susceptible. Treatment is with surgical debridement and antifungal drugs-ideally the lipid formulation of amphotericin B. CONCLUSION: Gastrointestinal basidiobolomycosis is a rare infection that can be fatal if not diagnosed and treated early.

International Journal Of Community Medicine And Public Health, 2018

Psoriasis is a chronic skin disorder with various morphology, distribution, severity, and course ... more Psoriasis is a chronic skin disorder with various morphology, distribution, severity, and course of disease. The goal of the management is to control disease activity to a level that allows a sufficient quality of life with minimal toxicity from the treatment itself. Unfortunately, 25% of patients suffering from psoriasis experience major psychological distress. Its chronic nature with associated comorbidities has a negative impact on quality of life. We conducted this review using a comprehensive search of MEDLINE, PubMed and EMBASE from January 1996 to March 2017. The following search terms were used: psoriasis, pathogenesis of psoriasis, psoriasis management, quality of life in psoriasis patients. We tried to study the pathogenesis, and management of psoriasis, and understand its effect on the quality of life of patients. Due to the chronic nature and its obvious visibility on skin, many patients suffer from major psychological adverse effects. In majority of the time the health ...

Annals of Saudi Medicine, 2005

Annals of Saudi Medicine, 2008

Predictors of obstructive sleep apnea in snorerst statistical errors To the Editor: I have read w... more Predictors of obstructive sleep apnea in snorerst statistical errors To the Editor: I have read with great interest the recently published article by Ibrahim and colleagues 1 in the Annals of Saudi Medicine and I appreciated the authors' efforts and work. However, I would like to make few comments on it because of the apparent flaws in results. First, the authors mentioned in the abstract that 39% of the females had obstructive sleep apnea (OSA) with a mean of respiratory disturbance index (RDI) of 27.8±26.5. In Table 1, it was shown that 17 of 41 females were RDI positive, which constituted 41.5% and not 39%. Second, in the results text, the authors stated that "OSA was seen more in nontQatari (n=84) subjects versus in Qatari subjects (n=38). The sum of both groups was 122, not 126 study participants, who were diagnosed as OSAso unless there were 4 participants of unknown nationality, there is an error. Third, the authors again contradict what was shown in Table 1 where they mentioned that females (of the OSA group) had a nontsignificant higher mean age of 51.8±8.2 years compared to 48.7±9.4 years in males. The table showed that figure 51.8±8.2 years belonged to females in the RDI negative group and not the OSA group, whereas the second figure did not exist at all. Moreover, the statistical analysis in the table compared between the age of OSA group and the negative group among males and females separately. Fourth, in the discussion, on page 424, the authors stated that "the frequency of PSG diagnosed OSA.was 72.4%", whereas the correct figure was previously mentioned by them as 66% (126

Canadian Urological Association Journal, 2015

Introduction: We compared the morbidity of whole gland salvage ablation using cryotherapy (CRYO) ... more Introduction: We compared the morbidity of whole gland salvage ablation using cryotherapy (CRYO) and high-intensity focused ultrasound (HIFU) for radio recurrent prostate cancer at a single centre over a 17-year period. Methods: Patients were divided in 3 cohorts. Group 1 included the first 65 patients treated with CRYO (1995-1998); Group 2 included the last 65 patients treated with CRYO (2002-2004), and Group 3 included 65 patients treated with HIFU (2006-2011). We analyzed the complications reported within at least 90 days of treatment or up to the last follow-up. Results: We tallied Clavien grade complications. For Groups 1, 2 and 3, we recorded the following Clavien I-II complications: 78, 49 and 13, respectively. For Clavien grade IIIa, 2, 5 and 4 for Groups 1, 2 and 3, respectively. For Clavien grade IIIb, 8, 2 and 3 for Groups 1, 2 and 3, respectively. Clavien grade II complications were statistically higher in Group 1 versus Group 2 (p = 0.005) and in Group 2 versus Group 3 (p = 0.0001). The rate of mild-moderate incontinence was significantly higher in the CRYO group compared to the HIFU cohort (p ≤ 0.05). The rate of urinary retention was significantly higher in Group 2 compared to Group 3 (p = 0.0005). The rates of severe incontinence (range: 1.5%-5%), need for surgical intervention (uniform at 1.5%), and recto-urethral fistulae (range: 1.5%-3%) were not statistically different. Conclusions: CRYO was associated with higher overall morbidity. The morbidity during the early experience with HIFU was lower than both subgroups of CRYO. This may reflect the advancement of technology or cumulative learning experience.

Journal of Pediatric Biochemistry, 2015

Cytokines play an important role in the pathophysiology of asthma by affecting airway remodeling ... more Cytokines play an important role in the pathophysiology of asthma by affecting airway remodeling and allergic reactions. We aimed to measure the serum concentrations of osteopontin (OPN) and interleukin (IL)-17 in a group of asthmatic and normal children to test the association of these two cytokines with the severity of asthma in Saudi children. Our study included 50 asthmatic and 50 normal children. Serum cytokines were measured by ELISA technique. Pulmonary function tests were performed in the asthmatic children. Serum levels of OPN and IL-17 were significantly increased in asthmatic children in comparison to control group. Also, the concentrations of OPN and IL-17 were significantly associated with asthma severity. There was a significant positive correlation between OPN and IL-17 levels. In conclusion, our study suggests that OPN and IL-17 may play a role in childhood asthma and are strongly related to the disease severity.

2010 10th IEEE International Conference on Computer and Information Technology, 2010

Abstract We propose a novel approach for the collaborative enforcement of security policies in di... more Abstract We propose a novel approach for the collaborative enforcement of security policies in distributed systems that is based on the dynamic (re-) deployment of multiple PDPs. The policies enforced by the collaborating PDPs are analysed and decomposed from a system wide policy as present in current centralized approaches. The security policy is decomposed into sub-policies based on an object domain approach so the decisions are local to the object&amp;amp;#x27;s domain. The classes of policies investigated are dynamic history-based access ...

The Journal of Sexual Medicine, 2014

Introduction. Optimal oncologic control of higher stage prostate cancers often requires sacrifici... more Introduction. Optimal oncologic control of higher stage prostate cancers often requires sacrificing the neurovascular bundles (NVB) with subsequent postoperative erectile dysfunction (ED), which can be treated with interposition graft using sural nerve. Aims. To examine the long term outcome of sural nerve grafting (SNG) during radical retropubic prostatectomy (RRP) performed by a single surgeon. Methods. Sixty-six patients with clinically localized prostate cancer and preoperative International Index of Erectile Function (IIEF) score >20 who underwent RRP were included. NVB excision was performed if the risk of side-specific extra-capsular extension (ECE) was >25% on Ohori' nomogram. SNG was harvested by a plastic surgeon, contemporaneously as the urologic surgeon was performing RRP. IIEF questionnaire was used pre-and postoperatively and at follow-up. Main Outcome Measures. Postoperative IIEF score at three years of men undergoing RRP with SNG. Recovery of potency was defined as postoperative IIEF-EF domain score >22. Results. There were 43 (65%) unilateral SNG and 23 (35%) bilateral SNG. Mean surgical time was 164 minutes (71 to 221 minutes).The mean preoperative IIEF score was 23.4 + 1.6. With a mean follow-up of 35 months, 19 (28.8%) patients had IIEF score >22. The IIEF-EF scores for those who had unilateral SNG and bilateral SNG were 12.9 + 4.9 and 14.8 + 5.3 respectively. History of diabetes (P = 0.001) and age (P = 0.007) negatively correlated with recovery of EF. 60% patients used PDE5i and showed a significantly higher EF recovery (43% vs. 17%, P = 0.009). Conclusions. SNG can potentially improve EF recovery for potent men with higher stage prostate cancer undergoing RP. The contemporaneous, multidisciplinary approach provides a good quality graft and expedited the procedure without interrupting the work-flow. Siddiqui KM, Billia M, Mazzola CR, Alzahrani A, Brock GB, Scilley C, and Chin JL. Three-year outcomes of recovery of erectile function after open radical prostatectomy with sural nerve grafting.

Pituitary, 2005

Infarction of prolactin-secreting or growth hormone-secreting pituitary adenomas is not unusual. ... more Infarction of prolactin-secreting or growth hormone-secreting pituitary adenomas is not unusual. However, Infarction of ACTH-secreting adenomas has rarely been reported. Cyclical course of Cushing's syndrome alternating with adrenal insufficiency due to recurrent infarction of an ACTH-secreting pituitary adenoma has not been reported. We report here a 20-year-old lady who presented with florid signs of Cushing's syndrome but was found to have adrenal insufficiency on biochemical evaluation. Magnetic resonance imaging (MRI) of the pituitary gland showed that she had infarction of an ACTHsecreting macroadenoma. Over the next 6 years, her disease ran a cyclical course characterized by periods of hypercortisolism alternating with adrenal insufficiency due to repeated episodes of infarctions of the ACTH-secreting pituitary macroadenoma with corresponding changes in the pituitary adenoma on serial MRIs. The case alerts clinicians to this possibility when a patient presents with clinical picture of Cushing's syndrome but has adrenal insufficiency on biochemical testing. It also suggests that silent or subclinical infarction of pituitary adenomas is not uncommon and is probably under diagnosed.

All Days, 2007

Acid fracturing treatments are commonly used to enhance the productivity of carbonate formations ... more Acid fracturing treatments are commonly used to enhance the productivity of carbonate formations with low permeability zones. Various forms of HCl acid are used to create deep etched fractures. However, HCl reacts very fast with the carbonate rocks and unless retarded, will produce a fracture with low conductivity. In addition, concentrated HCl-based acids are very corrosive to well tubulars, especially at high temperatures. To address problems associated with concentrated acids, various retarded acids were introduced. Organic acids were also used in some cases. These acid systems were successfully used to acid fracture several wells in a deep gas reservoir in Saudi Arabia. Field data, however, indicated that there is a need to create deeper and more conductive fractures. To achieve this goal, it was decided to conduct a field trial with a newly developed acid system.The new acid system is an ester of an organic acid in the form of solid beads. The ester reacts with water (hydrolyze...

Oncogene, 2005

Medullary thyroid carcinoma (MTC) is a malignant tumour of the calcitonin-secreting parafollicula... more Medullary thyroid carcinoma (MTC) is a malignant tumour of the calcitonin-secreting parafollicular C cells of the thyroid, and occurs sporadically or as a component of the multiple endocrine neoplasia (MEN) type 2/familial medullary thyroid carcinoma (FMTC) syndromes. In the present study, we investigated the frequency of mtDNA mutations in 26 MTC tumour specimens (13 sporadic and 13 familial MTC) and their matched normal tissues by sequencing the entire coding regions of mitochondrial genome. Nonsynonymous mutations were detected in 20 MTC samples (76.9%): nine out of 13 sporadic MTC (69.2%) and 11 out of 13 (84.6%) familial MTC/MEN2. Both transition and transversion types of mutations were found in the samples. Interestingly, 76.2% (16/21) of transversion mutations were found in FMTC/MEN2 patients, whereas 66.7% (12/18) of transition mutations were in sporadic MTC. Synonymous mutations were found in 12 MTC samples. In total, we identified 27 transversion mutations (21 nonsynonymous and six synonymous) in MTC. Of them, 22 (81.5%) were from FMTC/MEN2, and five (18.5%) were from sporadic MTC. The association of transversion mutation with familial MTC/MEN2 was statistically significant (P ¼ 0.0015, binomial test). Majority of the mutations were involved in the genes located in the complex I of the mitochondrial genome, and were often resulting in a change of a moderately or highly conserved amino acid of their corresponding protein. Mitochondrial respiratory function was also compromised in a TT cell line, which carries mtDNA mutation at nt 4917 and 11 720, and in peripheral lymphocytes of MTC patients with mtDNA mutations. These data suggest that mtDNA mutation may be involved in MTC tumourigenesis and progression. Given that mtDNA mutation spectra are different between sporadic and familial MTC, different mechanisms of oxidative DNA damage may occur in the disease process.

The Journal of Urology, 2011

Journal of Endocrinological Investigation, 2005

Following the initial management, some patients with differentiated thyroid cancer (DTC) develop ... more Following the initial management, some patients with differentiated thyroid cancer (DTC) develop a state of high thyroglobulin (Tg) and negative diagnostic radioactive iodine (RAI) whole body scan (DxWBS). The predisposing factors and outcome of this condition are unclear. In this study, our objectives were to determine the predictive factors for the development of high Tg and negative DxWBS (Tg+/scan-) and to study the long-term course of the disease in patients with this condition. We, retrospectively, reviewed the medical records of a cohort of 105 non-selected DTC patients (26 males and 79 females; median age 37.7 yr, range 7-72). None of these patients had positive Tg antibodies or distant metastases. All Tg levels were obtained off thyroid hormone therapy. At the first follow-up visit after RAI ablation (13 +/- 7.6 months), patients were classified into those with low Tg (&amp;lt;2 ng/ml off L-T4) and negative DxWBS (control group) and those with high Tg ( &amp;gt; or = 22 ng/ ml off L-T4) and negative DxWBS (Tg+/scan- group). Using univariate and multivariate logistic regression analyses, we evaluated a number of parameters (see results) for their association with the development of Tg+/scan-. In addition, the long-term course of the disease in Tg+/scan- group was analyzed. In univariate analysis, the following factors were found to be significantly associated with Tg+/scan-: perithyroidal tumor extension (p=0.025), soft tissue invasion (p=0.001), cervical lymph node metastases (p=0.014) and Tg level before RAI ablation (p=0.015). In multivariate analysis, only soft tissue invasion remained significantly associated with Tg+/scan- [p 0.001, odds ratio, 15.6 (95% Cl, 2.96-82.06)]. Age, sex, duration of goiter before surgery, pressure symptoms, tumor size, tumor multifocality, lymph nodedissection at initial surgery, tumor-node-metastasis (TNM) stage, and RAI ablative dose were not associated with Tg+/ scan-. In 53 patients with Tg+/scan-, 42 cases were followed without any therapeutic intervention; over a median follow-up of 71.6 months (range, 13-144.7), 31 cases had a spontaneous remission and 11 cases continued to have a persistent disease (Tg &amp;gt; or = 2 ng/ml, negative DxWBS, and no palpable disease or distant metastases); Tg declined from 9.32 +/- 9.91 ng/ml at first visit after RAI ablation to 1.59 +/- 5.39 ng/ml at last visit (p&amp;lt;0.0001). In the other 11 cases of Tg+/scan- group, one or more therapeutic interventions (RAI, surgery, or external radiotherapy) were undertaken. Over a median follow-up of 98.4 months (range, 6-147), Tg decreased from 110.2 +/- 147.5 to 23.5 +/- 41.2 ng/ml (p 0.026); 4 cases achieved remission, 5 cases continued to have persistent disease, and 2 cases had progression of their disease, which led to their death. Soft tissue invasion on original surgery strongly predicts the development of Tg+/scan- in DTC patients. The long-term course of the disease is mostly favorable especially when the Tg level is only modestly elevated.

Journal of Biological Chemistry, 2013

Background: The tumorigenic potential of mTOR has not been established. Results: Mutations of the... more Background: The tumorigenic potential of mTOR has not been established. Results: Mutations of the mTOR gene confer gain-of-function to it and induce cell transformation, anchorage-independent growth, invasion, and tumorigenesis. Conclusion: The mTOR gene is tumorigenic upon mutation. Significance: The results demonstrate for the first time the tumorigenicity of mTOR, hence establishing its oncogenicity and important role in human tumorigenesis.

Endocrine-Related Cancer, 2009

The putative role of leptin and its receptor (Ob-R) in the pathogenesis of various primary human ... more The putative role of leptin and its receptor (Ob-R) in the pathogenesis of various primary human malignancies has been reported; however, their role in papillary thyroid cancer (PTC) has not yet been evaluated. We investigated the role of Ob-R in a large tissue microarray cohort of PTC followed by in vitro studies using a panel of PTC cell lines. Ob-R overexpression was seen in 80% PTCs and was significantly associated with poor disease-free survival (P=0.0235). PTCs that overexpressed Ob-R showed a aggressive phenotype characterized by older age, extrathyroid extension, larger tumor size, nodal metastasis, advanced stage, tall cell variant histological subtype, and a poor disease-free survival (P=0.0005, P=0.0006, P=0.0398, P=0.0004, P=0.0111, P=0.0003, and P=0.0235 respectively). However, Ob-R expression was not an independent prognostic marker to predict disease-free survival in multivariate analysis. PTCs with overexpression of Ob-R showed a significant direct association with o...

Endocrine-Related Cancer, 2012

The impact of metastasized cervical lymph nodes (CLN) identified on central neck dissection (CND)... more The impact of metastasized cervical lymph nodes (CLN) identified on central neck dissection (CND) on the recurrence/persistence of papillary thyroid cancer (PTC) and the extent of CND needed to reduce recurrence/persistence have not been firmly established. To assess the impact of CLN metastasis andBRAFmutation on the recurrence/persistence of PTC and the potential ofBRAFmutation in assisting CND. Analyses of 379 consecutive patients with PTC who underwent thyroidectomy with (n=243) or without CND (n=136) at a tertiary-care academic hospital during the period 2001–2010 for their clinicopathological outcomes andBRAFmutation status. Increasingly aggressive tumor characteristics were found as the extent of CND was advanced following conventional risk criteria from non-CND to limited CND to formal CND. Disease recurrence/persistence rate also sharply rose from 4.7% to 15.7% and 40.5% in these CND settings respectively (P<0.0001). CLN metastasis rate rose from 18.0 to 77.3% from limit...