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Biomedical subjects

A Silverman

Publications and source records attributed to A Silverman.

At least 19 recordsLinked to original sources
PubMed2006

A randomized controlled psycho-education intervention trial: Improving psychological readiness for successful HIV medication adherence and reducing depression before initiating HAART.

The purpose of this study was to evaluate a novel psycho-educational intervention intended to increase patients' medication preparedness and treatment adherence skills before initiating highly active antiretroviral therapy (HAART). Sixty-three HIV-positive patients not currently on antiretroviral therapy participated in a randomized controlled trial of a standardized, four-session psycho-educational intervention (Supportive Therapy for Adherence to Antiretroviral Treatment; STAART). Session topics included learning techniques to increase medication adherence and learning effective strategies to cope with stress and depression. Patients completed psychological questionnaires assessing psychological readiness to initiate HAART and depressed mood. They completed both measures at study baseline and at four-weeks post-baseline. After controlling for baseline medication readiness scores, intervention patients (n = 30) reported significantly higher mean medication readiness following the STAART intervention (four-weeks post-baseline) (27.3+/-6.9) compared to controls (n = 33; 24.6+/-9.9; p < 0.05). Among depressed patients (n = 27), those receiving the intervention (n = 15) reported significantly lower mean depression scores at four-weeks post-baseline (22.5+/-12.9) compared to controls (n = 12; 27+/-9.9; p < 0.05). The STAART intervention enhanced HIV treatment readiness by better preparing patients prior to initiating HAART. It was also beneficial for reducing depressive symptoms in depressed, HIV-positive patients.

Adaptation, Psychological↗
PubMed2000

Time estimation by pigeons on a fixed interval: the effect of pre-feeding.

Pigeons well trained on a fixed interval 10-s schedule of reinforcement were tested on the peak procedure. In a successive conditions design, they were either pre-fed or not in the experimental setting. Pre-feeding decreased the rate of responding. It also led to a maximum rate of responding that occurred 2-3 s later than in the control condition, where the maximum occurred at the usual time of reinforcement. The shift in peak time in response to pre-feeding shows that peak time may not be a pure measure of timing. The results are also interpreted in terms of timing theories.

Journal Article↗
PubMed1999

End-stage renal disease in two pediatric patients with Fechtner syndrome.

Fechtner syndrome, a disease in the spectrum of the hereditary nephridites, is a macrothrombocytopenia associated with sensorineural hearing loss, cataracts, nephritis, and characteristic leukocyte inclusions. Renal biopsy findings are consistent with those of Alport syndrome, and the associated renal disease is said to be unusual before mid to late adulthood. Here, we review the available literature on this disease and report two African-American pediatric patients with Fechtner syndrome who rapidly progressed to end-stage renal disease during adolescence. We conclude that chronic renal failure can occur at a young age in patients with Fechtner syndrome, with a possible relation to race/ethnicity. Fechtner syndrome, or other variants of Alport syndrome, need to be considered in patients presenting with proteinuria and thrombocytopenia.

Adolescent↗
PubMed1999

Cyclin D- and E-dependent kinases and the p57(KIP2) inhibitor: cooperative interactions in vivo.

This study examines in vivo the role and functional interrelationships of components regulating exit from the G1 resting phase into the DNA synthetic (S) phase of the cell cycle. Our approach made use of several key experimental attributes of the developing mouse lens, namely its strong dependence on pRb in maintenance of the postmitotic state, the down-regulation of cyclins D and E and up-regulation of the p57(KIP2) inhibitor in the postmitotic lens fiber cell compartment, and the ability to target transgene expression to this compartment. These attributes provide an ideal in vivo context in which to examine the consequences of forced cyclin expression and/or of loss of p57(KIP2) inhibitor function in a cellular compartment that permits an accurate quantitation of cellular proliferation and apoptosis rates in situ. Here, we demonstrate that, despite substantial overlap in cyclin transgene expression levels, D-type and E cyclins exhibited clear functional differences in promoting entry into S phase. In general, forced expression of the D-type cyclins was more efficient than cyclin E in driving lens fiber cells into S phase. In the case of cyclins D1 and D2, ectopic proliferation required their enhanced nuclear localization through CDK4 coexpression. High nuclear levels of cyclin E and CDK2, while not sufficient to promote efficient exit from G1, did act synergistically with ectopic cyclin D/CDK4. The functional differences between D-type and E cyclins was most evident in the p57(KIP2)-deficient lens wherein cyclin D overexpression induced a rate of proliferation equivalent to that of the pRb null lens, while overexpression of cyclin E did not increase the rate of proliferation over that induced by the loss of p57(KIP2) function. These in vivo analyses provide strong biological support for the prevailing view that the antecedent actions of cyclin D/CDK4 act cooperatively with cyclin E/CDK2 and antagonistically with p57(KIP2) to regulate the G1/S transition in a cell type highly dependent upon pRb.

Animals↗
PubMed1998

The Ink4a tumor suppressor gene product, p19Arf, interacts with MDM2 and neutralizes MDM2's inhibition of p53.

The INK4a gene encodes two distinct growth inhibitors--the cyclin-dependent kinase inhibitor p16Ink4a, which is a component of the Rb pathway, and the tumor suppressor p19Arf, which has been functionally linked to p53. Here we show that p19Arf potently suppresses oncogenic transformation in primary cells and that this function is abrogated when p53 is neutralized by viral oncoproteins and dominant-negative mutants but not by the p53 antagonist MDM2. This finding, coupled with the observations that p19Arf and MDM2 physically interact and that p19Rrf blocks MDM2-induced p53 degradation and transactivational silencing, suggests that p19Arf functions mechanistically to prevent MDM2's neutralization of p53. Together, our findings ascribe INK4a's potent tumor suppressor activity to the cooperative actions of its two protein products and their relation to the two central growth control pathways, Rb and p53.

Animals↗
PubMed1998

An S100 negative granular cell tumor with malignant potential: report of a case.

Malignant granular cell tumors are rare, but exhibit typical histologic, immunohistochemical, and electron microscopic features that also characterize their benign counterparts. Although most granular cell tumors are S100 protein positive, we report an S100 negative granular cell tumor with histopathologic evidence supporting malignancy. This tumor is best categorized as a malignant granular cell tumor rather than a granular cell variant of a malignant histiocytic, mesenchymal, or epithelial neoplasm. A multidisciplinary approach is essential to diagnosis.

Cell Nucleolus↗
PubMed1997

Altered cell differentiation and proliferation in mice lacking p57KIP2 indicates a role in Beckwith-Wiedemann syndrome.

Mice lacking the imprinted Cdk inhibitor p57(KIP2) have altered cell proliferation and differentiation, leading to abdominal muscle defects; cleft palate; endochondral bone ossification defects with incomplete differentiation of hypertrophic chondrocytes; renal medullary dysplasia; adrenal cortical hyperplasia and cytomegaly; and lens cell hyperproliferation and apoptosis. Many of these phenotypes are also seen in patients with Beckwith-Wiedemann syndrome, a pleiotropic hereditary disorder characterized by overgrowth and predisposition to cancer, suggesting that loss of p57(KIP2) expression may play a role in the condition.

Abdomen↗
PubMed1997

Treatment of chronic hepatitis C with interferon alfa-n3: a multicenter, randomized, open-label trial.

We studied the antiviral effectiveness and safety of interferon alfa-n3, a natural alpha interferon which contains multiple interferon species, in the treatment of previously untreated patients with chronic hepatitis C. Seventy-seven patients were randomized to receive either 1.0, 2.5, 5.0, or 10.0 million units (MU) of interferon alfa-n3 three times a week for 24 weeks and were then followed for an additional 24 weeks. At the end of therapy, 67% of patients in the 10 MU group normalized serum alanine transaminase (ALT) levels and 59% had no hepatitis C virus (HCV) RNA detected by polymerase chain reaction. At the end of the follow-up period, 44% of patients in the 10 MU group maintained normal ALT, and 24% had nondetectable HCV RNA. Lower doses were much less effective. Interferon alfa-n3 was well tolerated and no patient developed neutralizing anti-interferon antibodies during or after the treatment period. Interferon alfa-n3 appears to be effective against hepatitis C virus and deserves further study in larger randomized controlled trials.

Adult↗
PubMed1997

Comparative histologic features of liver biopsy specimens from patients coinfected with hepatitis G and C viruses with chronic hepatitis C virus alone: an age-, sex-, disease duration-, and transmission-matched controlled study of chronic hepatitis.

Hepatitis G virus (HGV) is a recently described, parenterally spread, positive-strand RNA virus of the Flaviviridae family. There is a high rate of HGV coinfection in patients with hepatitis C virus (HCV). Whether HGV can cause or is pathogenetically related to clinically apparent chronic liver disease, or whether HGV alters the course of hepatitis C in patients who are coinfected with both viruses is unknown. We studied 13 biopsy specimens from 11 patients coinfected with HGV and HCV and compared them with 15 biopsy specimens from a group of patients infected only with HCV who were matched for age, sex, disease duration, and transmission mode to characterize the histologic features of coinfected liver biopsy specimens and to look for any histologic features that might allow identification of coinfected patients. Three of the biopsy specimens from coinfected patients had a modified histologic activity index score of minimal chronic hepatitis, three of mild, two of mild/moderate, and five of moderate chronic hepatitis. Bile duct injury was absent in seven specimens, minimal in five, and mild in one. The biopsy specimens from patients who were coinfected with HGV and HCV had similar histologic features to the biopsy specimens of patients infected with HCV alone. There were no detectable histologic differences between the biopsy specimens from the two patient groups. The P values for the statistical comparisons confirmed this impression. In addition, no group of histologic features distinguished the coinfected patient group from the control group. Any suspicion that a clinician might have about the presence of HGV requires confirmation by reverse transcriptase-polymerase chain reaction testing of serum samples. Our results suggest that HGV most likely does not actively participate in the cytotoxic effects of chronic hepatitis or does so by a mechanism as yet undefined. Although HGV can cause chronic infection, the present study provides no evidence that it causes or contributes to chronic hepatitis.

Biopsy↗
PubMed1995

Clearance of chronic hepatitis B virus infection in young children after alpha interferon treatment.

Nine children aged 18 months to 17 years (mean 5.7 years) with chronic hepatitis b virus infection and chronic active hepatitis were treated with 5 to 6 million units/m2 of body surface area of interferon -alpha 2b administered subcutaneously three times per week for 4 months (n = 1) or 6 months (n = 8). At 12 months after the start of therapy, six children less than 3 years of age responded to the treatment (three completely and three partially), whereas only one of three children older than 7 years of age responded. We conclude that IFN treatment may be effective in children with chronic HBV infection, especially when administered while they are young.

Adolescent↗
PubMed1995

Outcome of syndromic paucity of interlobular bile ducts (Alagille syndrome) with onset of cholestasis in infancy.

OBJECTIVE: To determine the outcome, in index patients followed at an American Center, of syndromic paucity of interlobular bile ducts (sPILBD; Alagille syndrome), with onset of cholestasis in infancy. DESIGN: Cohort. SETTING: Regional referral center for infants and children with liver disease. RESULTS: During the past 10 years, 26 unrelated children with sPILBD were identified. Fifteen (58%) are alive without liver transplantation at a median age of 12.1 years. Three (11%) died, all before 2 years of age. Eight patients (31%) underwent liver transplantation at a median age of 6.5 years; all eight are alive a median 5.4 years after transplantation. The most common factors contributing to the decision for transplantation were bone fractures, pruritus, and severe xanthoma. The predicted probability of reaching 19 years of age without transplantation is about 50%; however, with transplantation, the predicted probability of long-term survival is 87%. Of 26 patients 4 (15%) have had significant central nervous system disease, and two of them have died of intracranial hemorrhage. Of the four patients who underwent cholecystoportostomy or portoenterostomy, three required liver transplantation. CONCLUSIONS: Children with sPILBD identified in infancy because of cholestasis have a 50% probability of long-term survival without liver transplantation, a worse prognosis than other follow-up studies have reported. In selected patients, liver transplantation provides the opportunity for long-term survival with improved quality of life. Patients with sPILBD are at risk of having intracranial hemorrhage.

Alagille Syndrome↗
PubMed1995

Efficacy of intraoperative cultures obtained during revision total hip arthroplasty.

The purpose of this study was to determine the incidence of positive intraoperative cultures, correlate the findings of the permanent histopathology with the results of culture, and determine the natural history and predictive value of the positive intraoperative culture in a consecutive series of 138 revision total hip arthroplasties. The incidence of positive cultures was 30% (42 hips). Of these 42 hips, only 1 ultimately developed sepsis, requiring a second surgical procedure. After a mean follow-up period of 48 months, the remaining 41 culture-positive hips show no evidence of sepsis and are considered clinical successes. The histologic appearance of the infected case was characterized by polymorphonuclear leukocyte infiltration suggestive of acute inflammation. The remaining hips demonstrated findings of chronic inflammation consistent with a diagnosis of aseptic loosening. With the development of sepsis as an endpoint, the positive predictive value of a positive intraoperative culture is 2.4%. The results demonstrate that intraoperative cultures are an unreliable predictor of sepsis and that permanent histologic sectioning is a more useful tool in determining sepsis at the time of revision surgery.

Female↗
PubMed1995

Tars and anthralins.

The pharmacology, mechanisms of action, and historic perspectives of tar and anthralin are discussed. Traditional Goeckerman and Ingram regimens are presented in the context of newer advances in psoriasis treatment. Recommendations for therapy with tar and anthralin, either as monotherapy or adjunctive therapy, are reviewed and referenced.

Administration, Topical↗
PubMed1994

Gene for familial psoriasis susceptibility mapped to the distal end of human chromosome 17q.

A gene involved in psoriasis susceptibility was localized to the distal region of human chromosome 17q as a result of a genome-wide linkage analysis with polymorphic microsatellites and eight multiply affected psoriasis kindreds. In the family which showed the strongest evidence for linkage, the recombination fraction between a psoriasis susceptibility locus and D17S784 was 0.04 with a maximum two-point lod score of 5.33. There was also evidence for genetic heterogeneity and although none of the linked families showed any association with HLA-Cw6, two unlinked families showed weak levels of association. This study demonstrates that in some families, psoriasis susceptibility is due to variation at a single major genetic locus other than the human lymphocyte antigen locus.

Alleles↗
PubMed1994

Successful treatment of progressive mucocutaneous infection due to acyclovir- and foscarnet-resistant herpes simplex virus with (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC).

The acyclic nucleoside phosphonate (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC) was used topically for the treatment of persistent mucocutaneous infections in two cases. One patient with AIDS suffered from a perineal lesion due to infection with herpes simplex virus type 2 (HSV-2) and did not respond to acyclovir and was intolerant of foscarnet. A bone marrow transplant recipient developed orofacial lesions due to infection with herpes simplex virus type 1 (HSV-1) that failed to respond to therapy with both acyclovir and foscarnet. After topical application of HPMPC, the HSV-2 lesions completely resolved. However, the lesions recurred 3 weeks later, and, upon subsequent treatment with HPMPC, regressed. On recurrence, the virus was found to be sensitive to acyclovir, which the patient was given. Again HSV-2, which was resistant to acyclovir, emerged; similar observations were made after another cycle of HPMPC therapy. The HSV-1 isolates were resistant to acyclovir and foscarnet. Following local HPMPC treatment, the lesions regressed, but after 1 week, a second course of topical HPMPC therapy had to be instituted for recurrent infection. The lesions again regressed, and as the recurrent virus was sensitive to acyclovir, the patient was successfully treated with the drug. The results of this study point to the potential usefulness of topical HPMPC in the treatment of immunocompromised patients with HSV-related mucocutaneous infections that are refractory to therapy with acyclovir and/or foscarnet.

AIDS-Related Opportunistic Infections↗
PubMed1993

Prothymosin alpha gene expression correlates with proliferation, not differentiation, of HL-60 cells.

Accumulating evidence suggests that prothymosin alpha has an as yet undefined intracellular, perhaps intranuclear, function related to cell proliferation. Prothymosin alpha mRNA and/or peptide levels increase when cells are stimulated to proliferate. Because proliferation and differentiation events are often inversely correlated, we examined prothymosin alpha gene expression during proliferation and differentiation of HL-60 myeloid leukemia cells. Steady-state levels of prothymosin alpha mRNA, which are high in exponentially growing HL-60, decrease within hours after induction of HL-60 to differentiate along the neutrophil pathway with dimethylsulfoxide (DMSO) or along the macrophage lineage with either tetradecanoylphorbol acetate (TPA) or bryostatin 1. The decline in prothymosin alpha mRNA in response to these differentiation signals parallels that of c-myc mRNA under the same conditions. We then determined whether the downregulation of prothymosin alpha and c-myc mRNA were due to differentiation or cessation or proliferation. Recombinant human gamma-interferon induces monocytic differentiation of HL-60, but permits continued proliferation, and, under these conditions, expression of prothymosin alpha, as well as of c-myc, mRNA remains elevated. We conclude that prothymosin alpha and c-myc expression are coregulated in differentiating HL-60 and that their expression correlates with the proliferative state of HL-60 cells, rather than with the differentiated state.

Cell Differentiation↗