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Biomedical subjects

V Reddy

Publications and source records attributed to V Reddy.

At least 55 records · Page 3Linked to original sources
PubMed2000

Coccidioidomycosis in pregnancy during an epidemic in California.

OBJECTIVE: To determine presentation, clinical course, and outcome of a cohort of pregnant women with coccidioidomycosis and compare findings with common observations reported in the literature. METHODS: Thirty-two women who delivered live infants or aborted fetuses in 1993 and had confirmed diagnoses of coccidioidomycosis were included in the study. Medical records were evaluated retrospectively for clinical characteristics, laboratory results, and disease course. RESULTS: Dissemination occurred in three of 32 cases. The most common management was supportive and symptomatic care. At 1 year, 26 of 32 had recovered. There were no maternal deaths. CONCLUSION: The common depiction of coccidioidomycosis in pregnancy has overstated morbidity and mortality likely because of reporting bias. Many women will have favorable outcomes without drug treatment, and the practice of abortions or early delivery in subjects with active infection should be rare.

Adult↗
PubMed2000

Fibrotic aortic stenosis in a patient with dwarfism.

In this report, we present an adult patient with dwarfism who had severe aortic stenosis with markedly thickened fibrotic valve leaflets without calcification. These findings were well demonstrated by both two- and three-dimensional transesophageal echocardiography and confirmed at surgery and by pathological examination.

Adult↗
PubMed2000

A prospective trial of telepathology for intraoperative consultation (frozen sections).

Telepathology is a maturing technology that, for a variety of reasons, has not been widely deployed. In addition, clinical validation is relatively modest compared with accepted telemedicine applications such as teleradiology. A prototype telepathology system (Tele-Path(sm)) featuring high-resolution images selected from a remote microscope site has been developed at the University of Alabama at Birmingham (UAB). To validate the diagnostic efficacy of the system, a prospective study was undertaken of parallel diagnoses by conventional microscopy and telepathology with a remotely operated microscope. Slides from 99 intraoperative consultations from 29 tissue/ organ sites in the University of Alabama Hospitals by 9 academic pathologists were used in the study. Each microscopic and telepathology diagnosis was compared with the final diagnosis rendered by a referee pathologist. Diagnoses were classified as correct, false positive, or false negative or classification error. Of the 99 frozen sections evaluated, 3 cases were deferred. Of the remaining 96 cases, 2 received incorrect diagnoses in both the microscopic and telepathology arms of the study. Three errors occurred only in the telepathology arm. There was 1 false-positive diagnosis, 1 false-negative diagnosis, and 1 classification error. Statistical analysis indicated no significant difference between telepathology and conventional microscopy. Qualitative data indicated that the pathologists were generally satisfied with the performance of the system. Telepathology using this system paradigm is sufficiently accurate for real time utilization in a complex surgical environment. Telepathology therefore may be an effective model to support the surgical services of hospitals lacking full-time pathology coverage, resulting in full-time access to anatomic pathology services.

Diagnostic Errors↗
PubMed2000

Cocaine increases beta-myosin heavy-chain protein expression in cardiac myocytes.

BACKGROUND: As many as 47% of chronic cocaine users develop cardiac ventricular hypertrophy. The presence and degree of cocaine-induced ventricular hypertrophy is not correlated with the use of other substances of abuse such as alcohol or cigarettes. Moreover, this hypertrophy occurs in individuals without sustained increases in arterial blood pressure or heart rate, or increases in the plasma concentration of renin, aldosterone, norepinephrine, or cortisol. Therefore, we investigated whether cocaine, in concentrations commonly found in cocaine users, has any direct effects on the protein content in cardiac ventricular myocytes. We compared the effects of cocaine with norepinephrine, which increases the total protein content, especially beta-myosin heavy-chain contractile protein (beta-MHC), in cardiac ventricular myocytes. METHODS: Experiments were performed on 30-day-old rat ventricular myocytes suspended in culture media and cultured in flasks. In 12 suspension-culture experiments, cocaine or norepinephrine, in doses of 0 (control) or 10(-6) mol/L was added to each culture and the cells were harvested on day 5. In 16 flask-culture experiments, cocaine or norepinephrine was added to each culture on day 7 in doses of 0 (control-vehicle), 10(-7), or 10(-6) mol/L and the cells were harvested on day 10. The total protein content and the myosin protein expression of the myocytes in each culture were determined. Juvenile and adult rat cardiac myosin protein is predominately alpha-myosin heavy-chain protein (alpha-MHC), whereas beta-MHC occurs primarily in fetal rat hearts. RESULTS: In the suspension-culture experiments, cocaine, 10(-6) mol/L, increased the cardiomyocyte total protein concentration by 29% +/- 2% (P <.001) and the beta-MHC expression by 81% +/- 10% (P <.01) in comparison with the control myocytes. Cocaine slightly decreased cardiomyocyte alpha-MHC. Norepinephrine increased the total protein concentration by 21% +/- 3% (P <.001) and the beta-MHC expression by 59% +/- 10% (P <.01), but did not increase alpha-MHC expression. In the flask-culture experiments, cocaine, 10(-6) mol/L, maximally increased the total protein concentration by 28% (P <.001), the protein/cell ratio by 57% +/- 10% (P <.01), and the beta-MHC expression by 85% +/- 8% (P <.01). Cocaine slightly decreased alpha-MHC. Norepinephrine, 10(-6) mol/L, maximally increased the total protein concentration by 35%, the protein/cell ratio by 63% +/- 9% (P <.01), and the expression of beta-MHC by 78% +/- 11% (P <. 01). Norepinephrine did not increase alpha-MHC expression. In 18 separate flask-culture experiments, cocaine, 10(-6) mol/L, was added to the cardiomyocyte cultures after the addition of phentolamine (n = 9), in concentrations of 10(-7) to 10(-5) mol/L, or metoprolol (n = 9), in concentrations of 10(-7) to 10(-5) mol/L. Neither phentolamine nor metoprolol inhibited the cocaine-induced increase in cardiomyocyte total protein content or the expression of beta-MHC. CONCLUSION: Cocaine, similar to norepinephrine, significantly increases the total protein content and the expression of beta-MHC in cardiac ventricular myocytes. In this manner, cocaine may cause cardiac ventricular hypertrophy. This process is not inhibited by alpha- or beta-adrenergic receptor blockade.

Animals↗
PubMed1999

Differential expression of cell survival and cell cycle regulatory proteins in cutaneous squamoproliferative lesions.

Previous models of cutaneous carcinogenesis have primarily focused on the regulation of keratinocyte (KC) proliferation and differentiation. However, it has become clear in many neoplastic systems that altered rates of cell death and/or inability to undergo growth arrest can also contribute to the development of cancer. Apoptosis-regulatory proteins include those that block apoptosis such as Bcl-2 and Bcl-x, whilst a related protein Bax promotes apoptosis. Cell cycle regulatory proteins include those associated with growth arrest, i.e. p21wafl, p53, and those associated with proliferation, i.e. Ki-67. Paraffin embedded samples from ten different lesions of squamous cell carcinoma (SCC), Bowen's disease (BD), keratoacanthomas (KA), and nine normal adult skin samples were stained by immunohistochemistry to detect expression of Bcl-2, Bcl-x, Bax, Ki-67, p21wafl, p53 and apoptosis (TUNEL assay). Compared to low levels of Bcl-x and Bcl-2 immunostaining in normal skin, all the squamoproliferative lesions had strong and diffuse KC expression of Bcl-x (>80%) but minimal to absent KC Bcl-2 expression (<15%). Bax immunopositivity was limited to the basal layer in normal skin and BD. In contrast, by examining serial sections both Bcl-x and Bax appeared to be coexpressed by the majority of malignant KCs in KA and SCC (>70%). These immunostaining profiles reveal that squamoproliferative lesions, including invasive transformed KCs, preferentially express Bcl-x over Bcl-2, in addition to upregulating their Bax levels. Even though there were numerous TUNEL positive cells in these squamoproliferative lesions, no other evidence of apoptosis was seen reinforcing the necessity to use caution when relying on TUNEL staining for identification of programmed cell death in skin biopsies. Normal sun-exposed skin had low but detectable p53 and rare p21wafl KC expression. Significantly higher numbers of p21wafl and p53 immunopositive KCs were noted throughout the lesions in BD and SCC in contrast to KA where p53 and rare p21wafl immunopositive KCs were primarily limited to the periphery of the tumor cell islands. In general, p53 KC expression was higher in all squamoproliferative lesions and sun-exposed normal skin compared to p21Wafl expression. Summary of the expression of cell cycle regulatory proteins for both p21wafl and p53 KC expression was: SCC > BD > KA, in marked contrast to Ki-67 KC expression which was: BD > KA > SCC. The relatively few malignant cells in SCC that were actively participating in the cell cycle (i.e. Ki-67 positive) suggests that these neoplasms may arise primarily by increased cell survival and resistance to apoptosis rather than by hyperproliferation. These studies emphasize the importance of examining multiple members of protein families that regulate apoptosis, proliferation, growth arrest, and differentiation. It is the overall balance between these cellular phenomena that determine whether a cell remains viable or undergoes programmed cell death and contributes to the appearance of a neoplasm. The overexpression of Bcl-x may confer a survival advantage to malignant KCs unable to growth arrest to repair damaged DNA (mutant p53) and/or undergo terminal differentiation (increased p21wafl). Thus, mutation or aberrant expression of such proteins may participate in the multistep process of carcinogenesis that gives rise to these squamoproliferative lesions.

Cell Cycle Proteins↗
PubMed1999

Management of allogeneic bone marrow transplant recipients at risk for cytomegalovirus disease using a surveillance bronchoscopy and prolonged pre-emptive ganciclovir therapy.

BACKGROUND: Patients undergoing allogeneic bone marrow transplant (BMT) are considered to be at increased risk of cytomegalovirus (CMV) disease if they and/or their donor are CMV seropositive pre-transplant. Although several pre-emptive strategies have been shown to be effective in preventing early CMV disease, the ability of pre-emptive strategies using prolonged ganciclovir therapy to reduce the incidence of late-onset CMV infection, disease and mortality has not been fully evaluated. OBJECTIVE: To assess the efficacy of 18 weeks of pre-emptive ganciclovir therapy in preventing late-onset (> 100 days post-transplant) CMV disease when administered to asymptomatic BMT patients found to have CMV in bronchoalveolar lavage (BAL) fluid obtained during a surveillance bronchoscopy approximately 35 days post-transplant. To determine whether or not survival of BMT recipients is influenced by pre-transplant donor and recipient CMV serostatus in the context of this pre-emptive ganciclovir strategy. STUDY DESIGN: Consecutive patients undergoing allogeneic BMT were assessed for their risk of developing CMV disease based on their pre-transplant CMV serostatus and that of their donor. Patients who were CMV seropositive and/or received marrow from a CMV seropositive donor underwent a surveillance bronchoscopy and BAL approximately 35 days post-transplant. Patients with positive BAL fluid for CMV received pre-emptive ganciclovir therapy for 18 weeks at decreasing dose levels. Patients considered to be at low risk for the development of CMV disease (donor and recipient CMV seronegative) were followed without intervention. RESULTS: Of 98 consecutive patients, 55 were considered to be at risk for CMV disease and underwent a surveillance bronchoscopy. Sixteen (29%) patients had a positive BAL fluid for CMV and were started on pre-emptive ganciclovir therapy. Two patients progressed and died with CMV-related pneumonia. One additional patient developed CMV-related enteritis on day 42 post-transplant and recovered with continuing ganciclovir treatment. Of the 39 patients with a negative BAL fluid for CMV, one developed a fatal CMV pneumonia 150 days post-transplant and two additional patients developed gastrointestinal CMV disease 28 and 57 days post-BMT, respectively. None of the patients in the low risk group developed CMV disease. CONCLUSIONS: The strategy utilizing a surveillance bronchoscopy for CMV and initiating prolonged (18 weeks) pre-emptive ganciclovir therapy for patients with a positive BAL fluid for CMV resulted in a low incidence of CMV-related post-transplant complications. After a minimum follow-up of 16 months, late CMV reactivations (occurring > 100 days post-transplant) were not observed in the group of individuals pre-emptively treated with ganciclovir. This observation suggests that prolonged therapy with a reduced dose of ganciclovir may be important in the prevention of CMV reactivation. The CMV serostatus of donors and recipients prior to BMT did not correlate with survival.

Adult↗
PubMed1999

Children with autism experience problems with both objects and people.

Kanner (1943), in his classic account, described autism as a specific impairment in interpersonal relations which leaves the child's uses of objects relatively unaffected. This combination of the difficulties in relating to people and the supposedly "excellent" relations to objects figures centrally within many of the current theories of autism, which have had relatively little to say on the question of object use. This paper draws attention to evidence of widespread impairments in relating to objects, not only in interpersonal aspects of object use but also in early sensorimotor exploration and the functional and conventional uses of objects. In stressing these problems with objects, our purpose is not to downplay the social dimension of autism, but rather to highlight the reciprocal nature of the interactions between the child, other people, and objects. Given the evidence that other people play an important role in introducing objects to children, we propose that an impairment in interpersonal relations should itself lead us to expect corresponding disruption in the autistic child's use of objects. Conversely, an unusual use of objects is likely to manifest itself in disturbances in relating to other people, given the importance of a shared understanding and use of objects in facilitating interaction.

Autistic Disorder↗
PubMed1999

A single amino acid in the adenovirus type 37 fiber confers binding to human conjunctival cells.

A 46-kDa receptor, coxsackievirus-adenovirus (Ad) receptor (CAR), mediates cell attachment of a number of different Ad serotypes; however, not all Ad serotypes utilize this receptor for infection. Moreover, the precise amino acid sequences in the Ad fiber protein that mediate cell attachment have yet to be identified. We investigated the interaction of subgroup D Ads with human ocular cells. Ad serotype 37 (Ad37), a virus associated with epidemic keratoconjunctivitis, but not a closely related virus serotype, Ad19p, exhibited preferential binding to and infection of human conjunctival cells. A single amino acid substitution in the Ad19p fiber distal domain (knob), Glu240 to Lys, conferred binding to conjunctival cells, while the reverse substitution in the Ad37 fiber abrogated cell binding. These findings provide new information on the fiber sequences that regulate Ad host cell tropism.

Adenoviridae↗
PubMed1999

Second messenger production in avian medullary nephron segments in response to peptide hormones.

We examined the sites of peptide hormone activation within medullary nephron segments of the house sparrow (Passer domesticus) kidney by measuring rates of hormone-induced generation of cyclic nucleotide second messenger. Thin descending limbs, thick ascending limbs, and collecting ducts had baseline activity of adenylyl cyclase that resulted in cAMP accumulation of 207 +/- 56, 147 +/- 31, and 151 +/- 41 fmol. mm-1. 30 min-1, respectively. In all segments, this activity increased 10- to 20-fold in response to forskolin. Activity of adenylyl cyclase in the thin descending limb was stimulated approximately twofold by parathyroid hormone (PTH) but not by any of the other hormones tested [arginine vasotocin (AVT), glucagon, atrial natriuretic peptide (ANP), or isoproterenol, each at 10(-6) M]. Thick ascending limb was stimulated two- to threefold by both AVT and PTH; however, glucagon and isoproterenol had no effect, and ANP stimulated neither cAMP nor cGMP accumulation. Adenylyl cyclase activity in the collecting duct was stimulated fourfold by AVT but not by the other hormones; likewise, ANP did not stimulate cGMP accumulation in this segment. These data support a tubular action of AVT and PTH in the avian renal medulla.

Adenylyl Cyclases↗
PubMed1999

N-demethylation of phenothiazines by lipoxygenase from soybean and human term placenta in the presence of hydrogen peroxide.

Several phenothiazine derivatives have been shown to cause reproductive toxicity. The biochemical mechanisms responsible for these effects are not fully understood at present. In this study, we investigated hydrogen peroxide-dependent oxidation of six phenothiazines by purified lipoxygenase from soybean (SLO) and human term placenta (HTPLO). Chlorpromazine was employed as the prototype phenothiazine drug. Chlorpromazine was easily demethylated releasing formaldehyde when incubated at pH 7.0 and 6.5 with SLO or HTPLO, respectively, in the presence of hydrogen peroxide. The reaction was linear with respect to time, exhibited dependence on the amount of enzyme, and the concentration of chlorpromazine and hydrogen peroxide. Under the optimal assay conditions, the estimated Vmax values for chlorpromazine N-demethylation were 139 and 7.2 nmoles/min/mg of SLO and HTPLO, respectively. Collectively, the results suggest an enzymatic nature of the reaction. In the presence of gossypol and NDGA, the classical inhibitors of different lipoxygenases, the formaldehyde production was significantly decreased, as expected. Similar to SLO, the generation of chlorpromazine cation radical, an initial oxidation product with an absorption maximum at 525 nm, was also observed with HTPLO. The radical generation was detectable only under acidic conditions (pH 3.5-4.5). The formaldehyde production was also decreased by BHT and BHA, suggesting a radical nature of the SLO-mediated chlorpromazine N-demethylation. Reduced glutathione, ascorbate, and dithiothreitol suppressed the rate of SLO-dependent formaldehyde generation, presumably due to the reduction of the cation radical back to chlorpromazine in a concentration-dependent manner. Besides chlorpromazine, SLO also oxidized promazine, triflupromazine, trifluperazine, trimeprazine, and perphenazine, albeit at different rates, in the presence of hydrogen peroxide. The evidence gathered in this in vitro study suggests that phenothiazines can undergo peroxidative N-demethylation via lipoxygenase pathway. The role of this biochemical mechanism in the in vivo developmental toxicity of phenothiazines remains to be established.

Chlorpromazine↗
PubMed1999

Oxidative stress induces differential gene expression in a human lens epithelial cell line.

PURPOSE: To identify differentially expressed genes in a human lens epithelial cell line exposed to oxidative stress. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) differential display was used to evaluate differential gene expression in a human lens epithelial cell line (SRA 01-04) when cells were exposed for 3 hours to a single bolus of 200 microM hydrogen peroxide. Differentially expressed genes were identified through DNA sequencing and a nucleotide database search. Differential expression was confirmed by northern blot and RT-PCR analyses. RESULTS: Using 18 primer sets, 28 RT-PCR products were differentially expressed between control and hydrogen peroxide-treated cells. In stressed cells, mitochondrial transcripts nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 4 and cytochrome b were downregulated 4-fold. Of the cytoplasmic mRNAs, glutamine cyclotransferase decreased 10-fold, whereas cytokine-inducible nuclear protein, alternative splicing factor 2, and beta-hydroxyisobutyryl-coenzyme A hydrolase increased 2-, 4-, and 10-fold, respectively. Analysis of mitochondrial transcripts in a 24-hour time course showed that NADH dehydrogenase subunit 4 mRNA decreased by 2-fold as early as 1 hour after oxidative stress, whereas the rate of decrease was slower for cytochrome b, cytochrome oxidase III, and 16S rRNA. CONCLUSIONS: Oxidative stress induced specific expressed gene changes in hydrogen peroxide-treated lens cells, including genes involved in cellular respiration and mRNA and peptide processing. These early changes may reflect pathways involved in the defense, pathology, or both of the lens epithelium, which is exposed to oxidative stress throughout life.

Blotting, Northern↗
PubMed1998

Malignant cutaneous and subcutaneous abdominal wall lesions: a fine-needle aspiration study.

Cutaneous and subcutaneous masses of the abdominal wall are uncommon. However, a variety of benign and neoplastic entities can be encountered in this region. We report a series of 22 fine-needle aspirations (FNA) of malignant cutaneous and subcutaneous lesions involving the abdominal wall. All of these lesions were metastatic neoplasms. There were 14 females and eight males, with an age range of 35-83 years (mean 65 years). Twenty-one had a previous history of malignancy. The mean interval between the primary diagnosis and FNA was 26 months (range 1.5-128 months). The sites of origin in order of decreasing frequency were colon (n = 4), ovary (n = 4), breast (n = 3), endometrium (n = 2), melanoma (n = 2), and one case each of cervix, urinary bladder, kidney, pancreas, gallbladder, and lymphoma. One case was a squamous-cell carcinoma of unknown origin. Fourteen of the 22 patients were dead at the end of this study, with a mean survival of 8.4 months (range 0.5-44 months) following FNA. One patient was alive with disease at 13 months, and seven patients were lost to follow-up. Based on this data and on review of the literature we conclude that the majority of malignant cutaneous and subcutaneous lesions of the abdominal wall subject to FNA biopsy are metastatic tumors which originate from intra-abdominal, pelvic, and retroperitoneal organs and that FNA is a highly useful technique in the assessment of these lesions of the abdominal wall.

Abdominal Muscles↗
PubMed1998

Pancreatic masses: a multi-institutional study of 364 fine-needle aspiration biopsies with histopathologic correlation.

Only 15% of primary malignant tumors are confined to the gland at the time of presentation. Fine-needle aspiration (FNA) is valuable in confirming the malignant nature of these unresectable lesions. Benign pancreatic lesions and metastatic neoplasms can also be evaluated by fine-needle aspiration. We undertook a retrospective study to evaluate the efficacy of FNA in assessing pancreatic masses. Three hundred and sixty-four radiologically guided FNAs of the pancreas performed between 1986-1996 were reviewed. Surgical material was also evaluated when available and compared to the FNA material. There were 223 men and 141 women. Their ages ranged from 23-90, with a mean of 64 yr. Two hundred and twelve patients (58%) had primary malignant tumors, 183 had adenocarcinomas, 15 had mucinous cystadenocarcinomas, 12 had neuroendocrine tumors, and 2 had pleomorphic giant-cell carcinomas. Ninety-one (43%) had available surgical material which showed adenocarcinoma. Ninety-one patients (25%) had benign aspirates, including 53 showing benign ductal epithelium, 23 showing pancreatitis/inflammation. 10 showing pseudocysts, and 7 showing serous cystadenomas. Surgical material was available in 24 (26%) of these patients. Two of these showed adenocarcinoma. Sixteen aspirates (4%) were suspicious for malignancy, 13 (81%) of which showed adenocarcinoma on follow-up biopsies. Twenty-two aspirates (6%) showed metastatic neoplasms. Twenty-three (6%) had unsatisfactory specimens. Ten (43%) of these had follow-up biopsies, 3 of which were malignant. FNA of primary benign and malignant pancreatic masses is highly sensitive (98%) and specific (100%). Eighty-one percent of the suspicious lesions showed adenocarcinoma on follow-up biopsy. FNA of metastatic neoplasms to the pancreas is also very accurate. This technique can be useful in avoiding unnecessary surgery.

Adult↗