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Biomedical subjects

S Alpert

Publications and source records attributed to S Alpert.

At least 19 recordsLinked to original sources
PubMed2001

Shared expectations for protection of identifiable health care information: report of a national consensus process.

OBJECTIVE: The Ethical Force Program is a collaborative effort to create performance measures for ethics in health care. This report lays out areas of consensus that may be amenable to performance measurement on protecting the privacy, confidentiality and security of identifiable health information. DESIGN: Iterative consensus development process. PARTICIPANTS: The program's oversight body and its expert panel on privacy include national leaders representing the perspectives of physicians, patients, purchasers, health plans, hospitals, and medical ethicists as well as public health, law, and medical informatics experts. METHODS AND MAIN RESULTS: The oversight body appointed a national Expert Advisory Panel on Privacy and Confidentiality in September 1998. This group compiled and reviewed existing norms, including governmental reports and legal standards, professional association policies, private organization statements and policies, accreditation standards, and ethical opinions. A set of specific and assessable expectations for ethical conduct in this domain was then drafted and refined through 7 meetings over 16 months. In the final 2 iterations, each expectation was graded on a scale of 1 to 10 by each oversight body member on whether it was: (1) important, (2) universally applicable, (3) feasible to measure, and (4) realistic to implement. The expectations that did not score more than 7 (mean) on all 4 scales were reconsidered and retained only if the entire oversight body agreed that they should be used as potential subjects for performance measurement. Consensus was achieved on 34 specific expectations. The expectations fell into 8 content areas, addressing the need for transparency of policies and practices, consent for use and disclosure of identifiable information, limitations on information that can be collected and by whom, individual access to one's own health records, security requirements for storage and transfer of information, provisions to ensure ongoing data quality, limitations on how identifiable information may be used, and provisions for meaningful accountability. CONCLUSIONS: This process established consensus on 34 measurable ethical expectations for the protection of privacy and confidentiality in health care. These expectations should apply to any organization with access to personally identifiable health information, including managed care organizations, physician groups, hospitals, other provider organizations, and purchasers. Performance measurement on these expectations may improve accountability across the health care system.

Confidentiality↗
PubMed1999

Decreased dopamine beta-hydroxylase activity in unipolar geriatric delusional depression.

BACKGROUND: Decreased dopamine beta-hydroxylase (DBH) activity has been reported in unipolar psychotic depression. DBH comparisons between elderly delusional and nondelusional depressives and controls and determination of whether pretreatment group differences persist have not been reported. Our objective was to compare DBH activity in elderly delusional major depressives with that of nondelusional depressives and normal control subjects before and after hospital treatment. METHODS: Enzyme activity was assessed after hospital admission. A subsample had predischarge assessments. Treatment was not controlled but accounted for in analyses. Electroconvulsive therapy subjects were medication-free for posttreatment assays. RESULTS: Baseline and predischarge DBH assays were lower in subjects with delusional depression than in either comparison group. Despite high intraindividual correlation, treatment was associated with significant increases in activity in the clinical groups. CONCLUSIONS: Patients with late-life delusional depression have lower DBH activity before and after hospital treatment than age-matched nondelusional patients or normal controls.

Age of Onset↗
PubMed1997

Pubic rami fracture: a benign pelvic injury?

OBJECTIVE: To present a consecutive series of older patients with pubic rami fractures and evaluate their long term functional outcome. STUDY DESIGN: Retrospective. METHODS: Sixty-three consecutive community-dwelling, ambulatory patients who sustained a public rami fracture and were treated at one hospital were reviewed. Fifty-two of sixty-three patients (83%) had radiographic evidence of pubic rami fracture at initial presentation; in the remaining eleven patients, the diagnosis of pubic rami fracture was made after additional imaging studies. Sixty patients (95%) required hospitalization for pain control and progressive mobilization. RESULTS: The hospital length of stay for the sixty admitted patients averaged fourteen days; patients who had three or more associated medical comorbidities or required use of a cane or walker for ambulation prior to fracture were more likely to have been hospitalized greater than two weeks. Thirty-eight patients were available for one year minimum follow-up; thirty-five of thirty-eight patients (92%) were living at home, 84% had no or mild complaints of hip/groin pain, 92% had returned to their prefracture ambulatory status, and 95% had returned to their performance function in activities of daily living. CONCLUSIONS: 1) Elderly patients with pubic rami fractures utilize substantial healthcare resources based upon length of stay and need for home care services; and 2) those patients who survive have a good prognosis with regard to long term pain relief and functional outcome.

Activities of Daily Living↗
PubMed1997

Patient safety and efficacy as measured by clinical trials and regulatory policy.

Virtual Reality and other technological innovations in medicine provide new challenges to the regulatory framework of the premarket review process for medical devices. By reinventing the government-academia-industry partnership, clinical trial data necessary for a medical device to enter the market can be more efficiently obtained.

Clinical Trials as Topic↗
PubMed1995

The relationship of granzyme A and perforin expression to cardiac allograft rejection and dysfunction.

The mechanisms underlying contractile dysfunction following heart transplantation are poorly defined. To investigate the role of cytotoxic T cells (CTL) in cardiac transplant rejection, and during episodic contractile dysfunction, we performed a prospective study analyzing the expression of granzyme A and perforin, two functional markers of activated CTL. Sixteen consecutive patients were analyzed during the first year posttransplantation. All patients received induction therapy with OKT-3 and received standard three-drug immunosuppression therapy. Rejection status was monitored using routine surveillance endomyocardial biopsy and graded according to the ISHLT scale. Granzyme A and perforin mRNA were detected by reverse transcription PCR at the time of each routine biopsy. A total of 64/123 biopsies were positive for granzyme expression, while 38/123 samples were positive for perforin expression. LV function was monitored using M-mode derived fractional shortening and Doppler assessment of diastolic function (isovolumic relaxation time [IVRT] and pressure half-time [P1/2]). As expected, the presence of granzyme A message was associated with rejection score (ANOVA, P = 0.001). In addition, granzyme A expression was correlated with a decrease in diastolic function (chi 2 = 6.4, P < 0.02), but was not associated with systolic function. The presence of perforin message was not correlated with functional changes or with rejection grade, but was associated with granzyme expression (chi 2 = 9.11, P = 0.0025). These studies suggest that the presence of granzyme A message may be an important predictor of graft function.

Adolescent↗
PubMed1995

Exposure to shear stress alters endothelial adhesiveness. Role of nitric oxide.

BACKGROUND: Shear stress increases the release of nitric oxide (NO) by endothelial cells (ECs). We and others have provided evidence that endothelium-derived NO inhibits monocyte adhesion to the vessel wall. We therefore hypothesized that previous exposure to shear stress would inhibit endothelial adhesiveness for monocytes by virtue of its effect to increase NO release. METHODS AND RESULTS: Confluent monolayers of bovine aortic endothelial cells, human aortic endothelial cells, or human venous endothelial cells were exposed to laminar fluid flow. Culture media were collected for measurement of NO (by chemiluminescence) and the prostacyclin metabolite 6-keto-prostaglandin F1 alpha. NOx and 6-keto-prostaglandin F1 alpha accumulated in the conditioned medium during laminar fluid flow from 30 minutes to 24 hours in a time-dependent fashion. In another set of studies, ECs previously exposed to flow or to static conditions were washed with Hanks' buffer and exposed to THP-1 cells for 30 minutes. Adherent cells were counted by microscopy. Previous exposure to flow reduced endothelial adhesiveness for monocytes by 50% (P < .05). The effect of flow on endothelial adhesiveness occurred within 30 minutes. This effect was abrogated by nitro-L-arginine (an antagonist of NO synthesis), as well as by tetraethylammonium ion (an antagonist of the flow-activated potassium channel); the effects of these inhibitors were reversed by the NO donor SPM-5185. Although the cyclo-oxygenase inhibitor indomethacin totally inhibited the flow-induced production of prostacyclin by ECs, it minimally affected adherence of THP-1 cells. The early effect of flow on endothelial adhesiveness was not mediated by alterations in the expression of the endothelial adhesion molecules VCAM-1 or ICAM-1 as assessed by fluorescent activated cell sorting. CONCLUSIONS: Shear stress alters endothelial adhesiveness for monocytes; at early time points, this effect is largely due to flow-stimulated release of NO and, to a lesser extent, prostacyclin. This effect of flow occurs within 30 minutes and is probably due to alterations in the signal transduction or activation state (rather than the expression) of endothelial adhesion molecules.

Animals↗
PubMed1994

Expression of granzyme A in salivary gland biopsies from patients with primary Sjögren's syndrome.

OBJECTIVE: To determine whether the destruction of salivary gland epithelial cells in Sjögren's syndrome (SS) could be mediated by granzyme A, a serine protease that is contained in the granules of activated lymphocytes. METHODS: We used in situ hybridization and polymerase chain reaction amplification to determine the expression of granzyme A messenger RNA (mRNA) in salivary gland biopsy samples. RESULTS: Granzyme A mRNA expression was detected in salivary glands from SS patients, but not in those from normal controls. Granzyme A mRNA content was significantly correlated (P < 0.001) with the size of lymphocytic infiltrates in the salivary glands and with the clinical activity of the disease. CONCLUSION: Cells that express granzyme A mRNA may play a role in the destruction of the target organ (i.e., the salivary gland) in patients with SS. The strong association of granzyme A mRNA expression and larger lymphoid infiltrates in the patients' salivary glands suggests that granzyme A mRNA is expressed at a relatively late stage of the local inflammatory process. Therapies designed to modulate or block granzyme A induction and action should be investigated in SS patients.

Adult↗
PubMed1994

An analysis of the expression of cyclophilin C reveals tissue restriction and an intriguing pattern in the mouse kidney.

Cyclophilin C (cyp C) is a cyclosporin A (CsA) binding protein originally isolated from a mouse bone marrow stromal cell line. We have compared the expression patterns of the mammalian cyclophilins A, B, and C in mouse tissues using in situ hybridization. These studies reveal that cyp C is expressed in a restricted subset of tissues including mouse ovary, testis, bone marrow, and kidney. Within the kidney, cyp C is highly expressed in a narrow zone in the outer medulla. Using monoclonal antibodies reactive against cyp C, we find that the kidney cells expressing cyp C correspond to the S3 segment of the nephron. The S3 segment has been shown to sustain histopathological damage from high dosages of CsA, raising the possibility that cyp C may be involved in mediating this damage.

Amino Acid Isomerases↗
PubMed1993

The use of granzyme A as a marker of heart transplant rejection in cyclosporine or anti-CD4 monoclonal antibody-treated rats.

Granzyme A is a serine protease expressed by populations of human and mouse natural killer cells and activated CD4+ and CD8+ cytotoxic lymphocytes; its expression marks a subset of inflammatory cells in allografts, autoimmune diabetes, and a number of other inflammatory lesions. In order to describe more completely the correlation between granzyme A expression and the presence of in vivo cytolytic effects, we grafted allogeneic rat hearts with vascular anastomoses in a heterotopic location, and treated the hosts with either cyclosporine, anti-CD4 monoclonal antibody (MRC OX38), or no therapy. The grafts were evaluated by palpation for cardiac functions, by immunohistochemistry for CD4/CD8 expression, by hematoxylin-and-eosin staining for inflammatory infiltration, and by in situ hybridization for granzyme A expression. The appearance of granzyme A+ cells in untreated allografts preceded both functional and standard histopathological and immunohistochemical evidence of graft rejection by two days. In donor-recipient combinations where cyclosporine and anti-CD4 treatments allowed indefinite allograft survival, the allografts showed minimal numbers of granzyme A+ cells, whether cellular infiltrates developed or not. The number of granzyme A+ cells present in the cardiac allografts in treated and untreated animals correlated with either current or impending episodes of rejection. The early time course of granzyme A expression suggests that it can be used as an early and reliable marker of graft rejection.

Animals↗
PubMed1993

Precursor cells of mouse endocrine pancreas coexpress insulin, glucagon and the neuronal proteins tyrosine hydroxylase and neuropeptide Y, but not pancreatic polypeptide.

The early progenitor cells to the pancreatic islets in the mouse have been characterized so as to re-examine their possible lineage relationships to the four islet cell types found in mature islets. Insulin and glucagon were both first expressed at embryonic day 9.5, and many cells coexpressed these two markers, as shown by light and electron microscopic analysis using double-label immunohistochemistry. Incubation of embryonic pancreas with 1% glutaraldehyde, a fixative commonly used by electron microscopists, abolished this reactivity, thereby explaining reported difficulties in detecting these precursor cells. Using antisera specific for neuropeptide Y (NPY) a peptide with considerable homology to pancreatic polypeptide (PP), we show that NPY first appears with insulin and glucagon immunoreactivity at E9.5, and is co-expressed with glucagon in a majority of adult alpha cells. As we have previously reported, PP itself is first detectable immunocytochemically at postnatal day 1 with PP-specific antibodies. However, antibodies raised against bovine PP are shown by dot blotting to recognize NPY with comparable avidity, indicating that a recent report of islet progenitor cells containing PP at E9.5 (Herrera, P. L., Huarte, J., Sanvito, F., Meda, P., Orci, L. and Vassalli, J. D. (1991) Development 113, 1257-1265), actually represents cross-reactivity to NPY. The data support a model in which early precursor cells to the endocrine pancreas co-activate and co-express a set of islet cell hormone and neural genes, whose expression is both selectively increased and extinguished as development proceeds, concomitant with a restriction to the patterns of expression characteristic of mature islet cell types.

Animals↗
PubMed1992

Differentiation of CD3-4-8- thymocytes in short-term thymic stromal cell culture.

We have investigated the ability of a heterogeneous thymic stromal cell (HTSC) culture system to promote in vitro differentiation of CD3-4-8- thymocytes. Culture of purified murine CD3-4-8- thymocytes on HTSC for 1 d resulted in the appearance of CD4+8+ cells, which did not occur when the sorted cells were maintained in medium alone. It is remarkable that when the culture period was extended to 2 d, CD3-4-8- progenitors differentiated further to CD4+8- and CD4-8+ cells, which also expressed high levels of TCR-CD3. This rapid differentiation on stroma in vitro appears to outpace parallel development in vivo. The differentiation potential of a subset of CD3-4-8- thymocytes that express high levels of a marker of normal and neoplastic thymic progenitors, the 1C11 antigen, was examined next. 1C11hiCD3-4-8- cells also gave rise to CD4-8+ and CD4+8+ populations after 1 d of culture on HTSC. Extending the culture period to 2 d resulted in a significant percentage of CD3-expressing cells that were CD4+8+, CD4+8- and CD4-8+ cells. These results suggest that in the in vitro HTSC culture system, various subsets of immature thymocytes can differentiate into all the mature phenotypes of cells normally found in the adult mouse thymus. This may provide a novel and rapid assay for thymic progenitors.

Animals↗
PubMed1992

Perforin and granzyme A expression identifying cytolytic lymphocytes in rheumatoid arthritis.

Lymphocytes from the synovial fluid of patients with rheumatoid arthritis were examined for the expression of granzyme A and perforin. Previous studies have demonstrated that the expression of these proteins, which are implicated as mediators of cytotoxicity, can be used to identify putative cytolytic lymphocytes in vivo. Twenty-two synovial fluid samples were analyzed by in situ hybridization and immunohistochemistry. In six patients receiving low doses of immunosuppressant, a population of granzyme A- and perforin-expressing lymphocytes could be identified. In contrast, lymphocytes from patients who were receiving high doses of immunosuppressant did not contain any granzyme A- or perforin-expressing lymphocytes. Synovial fluid lymphocytes from patients with osteoarthritis did not express either marker. The expression of these markers demonstrates the presence of potentially functional cytolytic lymphocytes, expressing proteins required to mediate killing, in the synovial fluid of patients with rheumatoid arthritis. This suggests that cytolytic lymphocytes may be involved in the pathogenesis of rheumatoid arthritis.

Arthritis, Rheumatoid↗