Md Shahrier Amin - Academia.edu (original) (raw)

Papers by Md Shahrier Amin

Kidney International, Sep 1, 2016

Apolipoprotein A-IV associated amyloidosis (AApoAIV amyloidosis) is a rare cause of amyloidosis w... more Apolipoprotein A-IV associated amyloidosis (AApoAIV amyloidosis) is a rare cause of amyloidosis with only a single reported case. Here we describe the clinical, biopsy, and mass spectrometry characteristics of 11 cases of renal AApoAIV amyloidosis encompassing 9 men and 2 women with a mean age at diagnosis of 63.5 years. Progressive chronic kidney disease (mean serum creatinine 2.9 mg/dl) was the most common cause for biopsy with proteinuria absent or minimal in all except one. Hematological and serological evaluation was negative in 9 patients, while 2 had a monoclonal gammopathy. The renal biopsy findings were striking and showed large amounts of eosinophilic Congo-red positive amyloid deposits restricted to the renal medulla with sparing of the renal cortex. In 6 cases, peritubular amyloid was noted in addition to the interstitial involvement. Immunofluorescence studies were negative for immunoglobulins. Electron microscopy showed nonbranching fibrils measuring 7 to 10 nm in diameter. Laser microdissection of the amyloid deposits followed by mass spectrometry showed large spectra number (a semiquantitative measure of abundance) for AApoAIV protein ranging from 49 to 169 (average 85), serum amyloid protein (average 19), and apolipoprotein E (average 48). Importantly, no peptides were detected for any other forms of known amyloidogenic precursor proteins. Thus, renal AApoAIV amyloidosis typically presents with progressive chronic kidney disease and histologically exhibits extensive medullary involvement with sparing of the cortex. The diagnosis is best established by mass spectrometry. Hence, a high degree of suspicion and examination of the renal medulla is required to make the diagnosis.

Frontiers in Cellular and Infection Microbiology, Jun 22, 2023

Pseudomonas aeruginosa is a common cause of hospital-acquired infections, including central line-... more Pseudomonas aeruginosa is a common cause of hospital-acquired infections, including central line-associated bloodstream infections and ventilatorassociated pneumonia. Unfortunately, effective control of these infections can be difficult, in part due to the prevalence of multi-drug resistant strains of P. aeruginosa. There remains a need for novel therapeutic interventions against P. aeruginosa, and the use of monoclonal antibodies (mAb) is a promising alternative strategy to current standard of care treatments such as antibiotics. To develop mAbs against P. aeruginosa, we utilized ammonium metavanadate, which induces cell envelope stress responses and upregulates polysaccharide expression. Mice were immunized with P. aeruginosa grown with ammonium metavanadate and we developed two IgG2b mAbs, WVDC-0357 and WVDC-0496, directed against the O-antigen lipopolysaccharide of P. aeruginosa. Functional assays revealed that WVDC-0357 and WVDC-0496 directly reduced the viability of P. aeruginosa and mediated bacterial agglutination. In a lethal sepsis model of infection, prophylactic treatment of mice with WVDC-0357 and WVDC-0496 at doses as low as 15 mg/kg conferred 100% survival against challenge. In both sepsis and acute pneumonia models of infection, treatment with WVDC-0357 and WVDC-0496 significantly reduced bacterial burden and infl ammatory cytokine production post-challenge. Furthermore, histopathological examination of the lungs revealed that WVDC-0357 and WVDC-0496 reduced inflammatory cell infiltration. Overall, our results indicate that mAbs directed against lipopolysaccharide are a promising therapy for the treatment and prevention of P. aeruginosa infections.

Clinical Case Reports, Jul 1, 2018

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial ... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

IJU case reports, Jun 29, 2022

Journal of Nephrology & Therapeutics, Jul 18, 2017

Radiology Case Reports, Nov 1, 2022

Kidney International, Apr 1, 2017

Gelsolin amyloidosis is a rare type of amyloidosis typically involving the cranial and peripheral... more Gelsolin amyloidosis is a rare type of amyloidosis typically involving the cranial and peripheral nerves, but rarely the kidney. Here we report the clinical, kidney biopsy, and mass spectrometry findings in 12 cases of renal gelsolin amyloidosis. Of the 12 patients, five were men and seven were women with mean age at diagnosis of 63.8 years. Gelsolin amyloidosis was most common in Caucasians (six patients) and Asians (four patients), and included one each African-American and Hispanic patients. Nephrotic syndrome was the most common cause of biopsy, although most patients also had progressive loss of kidney function. Hematological and serological evaluation was negative in 11 patients, while one patient had a monoclonal gammopathy. The renal biopsy showed large amounts of pale eosinophilic Congo red-positive amyloid deposits typically restricted to the glomeruli. Immunofluorescence studies were negative for immunoglobulins in nine cases with three cases of smudgy glomerular staining for IgG. Electron microscopy showed mostly random arrangement of amyloid fibrils with focally parallel bundles/sheets of amyloid fibrils present. Laser microdissection of the amyloid deposits followed by mass spectrometry showed large spectra numbers for gelsolin, serum amyloid P component, and apolipoproteins E and AIV. Furthermore, the p. Asn211Lys gelsolin mutation on mass spectrometry studies was detected in three patients by mass spectrometry, which appears to represent a renal-limited form of gelsolin amyloidosis. Thus, renal gelsolin amyloidosis is seen in older patients, presents with nephrotic syndrome and progressive chronic kidney disease, and histologically exhibits glomerular involvement. The diagnosis can be confirmed by mass spectrometry studies.

Statement of the problem: The epithelial sodium channels (ENaC) play an important role in regulat... more Statement of the problem: The epithelial sodium channels (ENaC) play an important role in regulation of blood pressure (BP). Although the genes are identical in Dahl salt sensitive (S) and Dahl salt resistant (R) rats, expression of ENaC subunits is increased in kidneys of S rats on high salt diet. Intracerebroventricular (icv) infusion of ENaC blocker benzamil prevents Na + induced hypertension. It was not known whether ENaC subunits are expressed in the brain and whether or not brain ENaC plays a role in regulation of [Na + ] in CNS. Hypothesis: 1. Epithelial sodium channels are expressed in the brain. 2. Expression of ENaC is increased in the kidneys and brain of Dahl S rats on high salt diet. 3. ENaC in the brain contributes to regulation of [Na + ] in the CSF and brain interstitium. Methods of investigation: We studied expression and distribution of the ENaC subunits and assessed the effects of icv infusion of Na +-rich aCSF in Wistar rats or high salt diet in Dahl S rats in different areas of the brain. Function of ENaC in the choroid plexus was evaluated by studying the effects of benzamil and ouabain on Na + transport. Major findings: In Wistar rats, both mRNA and protein of all three ENaC subunits are expressed in brain epithelia and magnocellular neurons in the supraoptic (SON) and paraventricular (PVN) nucleus. ENaC abundance is higher on the apical versus basolateral membrane of choroid cells. Benzamil decreases Na + influx into choroid cells by 20-30% and increases CSF [Na + ] by ~8 mmol/L. Na + rich aCSF increases apical membrane expression of βENaC in the choroid cells and of α and βENaC in basolateral membrane of ependymal cells, but has no effect on neuronal ENaC. Expression of ENaC is higher in choroid cells and SON of Dahl S versus R rats and the higher expression persists on a high salt diet. High salt attenuates the ouabain blockable efflux of Na + from choroid cells and has no effect on CSF [Na + ] in Dahl R rats. In contrast, high salt does not attenuate ouabain blockable efflux of 22 Na + and CSF [Na + ] increases in Dahl S. Main Conclusion: ENaC in the brain contributes to Na + transport into the choroid cells and appear to be involved in reabsorption of Na + from the CSF. Aberrant regulation of Na + transport and of Na + K + ATPase activity, might contribute to increases in CSF [Na + ] in Dahl S rats on high-salt diet. ENaC in magnocellular neurons may contribute to enhanced secretion of mediators such as 'ouabain' leading to sympathetic hyperactivity in Dahl S rats.

American Journal of Clinical Pathology, Oct 1, 2021

As the COVID-19 pandemic transitions to endemic, seasonal boosters are a plausible reality across... more As the COVID-19 pandemic transitions to endemic, seasonal boosters are a plausible reality across the globe. We hypothesize that intranasal vaccines can provide better protection against asymptomatic infections and more transmissible variants of SARS-CoV-2. To formulate a protective intranasal vaccine, we utilized a VLP-based platform. Hepatitis B surface antigen- based virus like particles (VLP) linked with receptor binding domain (RBD) antigen were paired with the TLR4-based agonist adjuvant, BECC 470. K18-hACE2 mice were primed and boosted at four-week intervals with either VLP-RBD-BECC or mRNA-1273. Both VLP-RBD-BECC and mRNA-1273 vaccination resulted in production of RBD-specific IgA antibodies in serum. RBD- specific IgA was also detected in the nasal wash and lung supernatants and were highest in VLP-RBD-BECC vaccinated mice. Interestingly, VLP-RBD-BECC vaccinated mice showed slightly lower levels of pre-challenge IgG responses, decreased RBD-ACE2 binding inhibition, and lowe...

The COVID-19 pandemic has been fueled by novel variants of concern (VOC) that have increased tran... more The COVID-19 pandemic has been fueled by novel variants of concern (VOC) that have increased transmissibility, receptor binding affinity, and other properties that enhance disease. The goal of this study is to characterize unique pathogenesis of the Delta VOC strain in the K18-hACE2-mouse challenge model. Challenge studies suggested that the lethal dose of Delta was higher than Alpha or Beta strains. To characterize the differences in the Delta strain’s pathogenesis, a time-course experiment was performed to evaluate the overall host response to Alpha or Delta variant challenge. qRT-PCR analysis of Alpha- or Delta- challenged mice revealed no significant difference between viral RNA burden in the lung, nasal wash or brain. However, histopathological analysis revealed high lung tissue inflammation and cell infiltration following Delta- but not Alpha-challenge at day 6. Additionally, pro-inflammatory cytokines were highest at day 6 in Delta-challenged mice suggesting enhanced pneumoni...

Academic Pathology, 2021

The following fictional case is intended as a learning tool within the Pathology Competencies for... more The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040 .1

JACC: Case Reports, 2021

Cardiac amyloidosis has recently garnered substantial attention. Although the advent of noninvasi... more Cardiac amyloidosis has recently garnered substantial attention. Although the advent of noninvasive diagnostic algorithms revolutionized diagnosis, endomyocardial biopsy may still be considered in select cases to determine the amyloidosis subtype definitively. We report a case of a patients with a known mutation causing hereditary apolipoprotein A-I-associated cardiac amyloidosis.

The Journal of bone and joint surgery. American volume, Jan 15, 2017

Arthroplasty implants commonly contain elemental metal that may undergo wear-related release. Rec... more Arthroplasty implants commonly contain elemental metal that may undergo wear-related release. Recently, cases of hip implant-associated myocardial injury have been reported. However, we are not aware of any previous study that has systematically measured myocardial metal levels or examined the relationship with total hip arthroplasty (THA). Archives of our institution were queried for autopsies of individuals who had undergone THA between 1990 and 2013. Myocardial tissue samples were analyzed for cobalt (Co) and chromium (Cr) levels with inductively coupled plasma mass spectroscopy. Seventy-five Co/Cr-on-polyethylene THA cases were included (mean age at time of death = 77.4 years; 49% women) as were 73 non-arthroplasty controls matched for age, sex, and history of hypertension and diabetes mellitus. Significantly higher median myocardial concentrations of Co were observed in individuals with THA compared with controls (0.12 versus 0.06 μg/g, p < 0.0001). The median Co concentrati...

Oncology Letters, 2012

BRCA1 overexpression and phosphoinositide 3-kinase (PIK3CA) pathway activation are involved in th... more BRCA1 overexpression and phosphoinositide 3-kinase (PIK3CA) pathway activation are involved in the resistance to DNA damaging agents. Thus, we hypothesized that BRCA1 protein expression and activating PIK3CA mutations are potential tumor biomarkers for the chemotherapeutic response to doxorubicin/cyclophosphamide plus docetaxel in locally advanced breast cancer. Informed consent was obtained and clinical, pathological and response data were collected. BRCA1 protein expression levels were assessed by immunohistochemistry of the archived tissue by two independent pathologists. The PIK3CA mutation status was assessed by nested PCR amplification and DNA sequencing. BRCA1 protein levels and the PIK3CA mutation status were correlated with pathological complete response and a partial response or better using the Chi-square test, Fisher's exact test and logistic regression. Of the 136 eligible participants, 59 samples could be analyzed. There was a trend of relatively low levels of BRCA1 protein achieving a pathological complete response (pCR), although this was not statistically significant [odds ratio (OR)=1.74; p=0.437]. Twenty-eight percent of patients had PIK3CA mutations, but no statistically significant association with pCR (OR= 0.977; p= 0.971) was noted. Neither BRCA1 protein levels (OR=1.18; p=0.818) nor PIK3CA mutations (OR=1.03; p=0.971) appeared to be associated with the likelihood of achieving a partial response or better from neoadjuvant chemotherapy. PIK3CA wild-type mutation status showed a trend towards an increased likelihood of not presenting with inflammatory disease (OR=5.34; p=0.101). In this exploratory study, neither BRCA1 protein expression levels nor the presence of PIK3CA mutations were significantly associated with chemotherapy response in locally advanced breast cancer. However, the relatively small sample size limits the overall interpretation.

Hypertension, Oct 1, 2009

To elucidate the role of epithelial sodium channels (ENaCs) and Na ϩ-K ϩ-ATPase in Na ϩ transport... more To elucidate the role of epithelial sodium channels (ENaCs) and Na ϩ-K ϩ-ATPase in Na ϩ transport by the choroid plexus, we studied ENaC expression and Na ϩ transport in the choroid plexus. Lateral ventricle choroid plexuses were obtained from young male Wistar, Dahl salt-resistant (SS.BN13), and Dahl salt-sensitive (SS/MCW) rats on a regular (0.3%) or high-(8.0%) salt diet. The effects of ENaC blocker benzamil and Na ϩ-K ϩ-ATPase blocker ouabain on sodium transport were evaluated by measuring the amounts of retained 22 Na ϩ and by evaluating intracellular [Na ϩ ] with Sodium Green fluorescence. In Wistar rats, ENaC distribution was as follows: microvilli, 10% to 30%; cytoplasm, 60% to 80%; and basolateral membrane, 5% to 10%. Benzamil (10 Ϫ8 M) decreased 22 Na ϩ retention by 20% and ouabain (10 Ϫ3 M) increased retention by 40%, whereas ouabain and benzamil combined caused no change. Similar changes were noted in intracellular [Na ϩ ]. In Dahl rats on a regular salt diet, intracellular [Na ϩ ] was similar, but the amount of retained 22 Na ϩ was less in sensitive versus resistant rats. High salt did not affect ENaC mRNA or protein, nor the benzamil induced decreases in retained 22 Na ϩ or intracellular [Na ϩ ] in either strain. However, high salt increased intracellular [Na ϩ ] and attenuated the increase in uptake of 22 Na ϩ by ouabain in resistant but not sensitive rats, suggesting a decrease in Na ϩ-K ϩ-ATPase activity only in resistant rats. These findings suggest that both ENaC and Na ϩ-K ϩ-ATPase regulate Na ϩ transport in the choroid plexus. Aberrant regulation of Na ϩ transport and of Na ϩ-K ϩ-ATPase activity, but not of ENaCs, might contribute to the increase in cerebrospinal fluid [Na ϩ ] in Dahl salt-sensitive rats on a high-salt diet.

The FASEB Journal, Mar 1, 2008

The FASEB Journal, Mar 1, 2006