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Biomedical subjects

F Shah

Publications and source records attributed to F Shah.

At least 19 recordsLinked to original sources
PubMed2001

Economics of reservoir sedimentation and sustainable management of dams.

Accepted practice has been to design and operate reservoirs to fill with sediment, generating benefits from remaining storage over a finite period of time. The consequences of sedimentation and project abandonment are left to the future. This 'future' has already arrived for many existing reservoirs and most others will eventually experience a similar fate, thereby imposing substantial costs on society. Such costs could be avoided if sedimentation was minimized and dams were allowed to live forever. The fact that the world's inventory of suitable reservoir sites is limited provides an additional reason for encouraging the sustainable management of dams. This paper provides a framework for assessing the economic feasibility of sediment management strategies that would allow the life of dams to be prolonged indefinitely. Even if reduced accumulation or removal of sediment is technically possible, its economic viability is likely to depend on physical, hydrological and financial parameters. The model presented incorporates such factors and allows a characterization of conditions under which sustainable management would be desirable. The empirical implementation of the model draws upon the substantial amount of technical information available. We analyze the sustainability of reservoirs, with a focus on the trade-off between such sustainability and the short to medium term benefits which a reservoir is expected to produce. The results show that, for a very wide range of realistic parameter values, sustainable management of reservoirs is economically more desirable than the prevailing practice of forcing a finite reservoir life through excessive sediment accumulation.

Environment↗
PubMed1998

Association of temporal arteritis, retinal vasculitis, and xanthomatosis with multiple myeloma: case report and literature review.

Bone pain, anemia, renal failure, and paraproteinemia are common manifestations in patients with multiple myeloma. In this article, we describe an elderly woman with multiple myeloma who had unusual manifestations of cutaneous xanthomatosis, temporal arteritis, and retinal vasculitis. The literature of the dermatologic, ocular, and rheumatologic manifestations of multiple myeloma is reviewed, and the clinical significance of vasculitis in multiple myeloma is discussed.

Aged↗
PubMed1998

Erythromycin.

Explore the source record for details and available documents.

Anti-Bacterial Agents↗
PubMed1996

Ethylene glycol ethers and risks of spontaneous abortion and subfertility.

Potential reproductive effects from occupational exposures to ethylene glycol ethers (EGE) are of concern since these organic solvents have been used widely in industry, and their reproductive toxicity has been well documented in animal studies. For determination of whether occupational exposure to EGE was associated with increased risks of spontaneous abortion and subfertility (i.e., taking more than 1 year of unprotected intercourse to conceive), a retrospective cohort study was conducted among workers at two semiconductor manufacturing plants in the eastern United States in 1980-1989 as part of a larger evaluation of reproductive health. Reproductive and occupational histories were obtained from interviews of semiconductor manufacturing workers and spouses. Assessment of potential exposure to mixtures containing EGE (none, low, medium, and high) was based on reported processes and company records. There were 1,150 pregnancies to semiconductor manufacturers, 561 to female employees and 589 to wives of male employees. Among female manufacturers, potential exposure to mixtures containing EGE was associated with increased risks of spontaneous abortion (relative risk in the high exposure group = 2.8; 95% confidence interval (CI) 1.4-5.6) and subfertility (odds ratio in the high exposure group = 4.6; 95% CI 1.6-13.3). Both of these risks exhibited a dose-response relation with potential EGE exposure (p for trend = 0.02). Among spouses of male manufacturers potentially exposed to mixtures containing EGE, there was no increased risk of spontaneous abortion, but there was a nonsignificant increased risk of subfertility (odds ratio in the high exposure group = 1.7; 95% CI 0.7-4.3).

Abortion, Spontaneous↗
PubMed1996

Human papillomavirus DNA detection in cervical specimens by hybrid capture: correlation with cytologic and histologic diagnoses of squamous intraepithelial lesions of the cervix.

Human papillomavirus (HPV) DNA detection in cervical specimens was correlated with cytologic and histologic diagnoses for 151 women who were referred to the Johns Hopkins Hospital colposcopy clinic for evaluation of an abnormal Pap smear. HPVs were identified as "high-risk" or "low-risk" by Hybrid Capture. The final disease status was categorized as high-grade squamous intraepithelial lesion (HSIL) by histology (n = 26), low-grade squamous intra-epithelial lesion (LSIL) by histology (n = 43), equivocal [histology negative, cytology atypical squamous cells of undetermined significance (ASCUS) or higher, n = 42], and negative (both histology and cytology negative, n = 40). Thirty-five percent of disease-negative women and 84% of the women with biopsy-proven or equivocal disease were HPV-positive. Ninety-two percent of the HPV-positive women harbored high-risk HPVs, either high-risk HPVs alone (77%) or high-risk HPVs along with low-risk HPVs (15%). High-risk HPVs predominated in disease-negative as well as disease-positive women. Collection of specimens with a cytobrush was more efficient for HPV DNA detection than collection by cervicovaginal lavage. Large amounts of HPV DNA correlated with presence of HSIL or LSIL. For detection of HSIL, considering only brush samples, the sensitivities of abnormal cytology (ASCUS or higher), of high-risk HPVs, and of the two combined were, respectively, 87, 93, and 100%; the corresponding specificities were 30, 30, and 20%. HPV DNA detection may be most beneficial in populations with low HPV prevalence.

Adult↗
PubMed1996

Body dysmorphic disorder: a cognitive behavioural model and pilot randomised controlled trial.

A cognitive behavioural model of body image is presented with specific reference to body dysmorphic disorder (BDD). We make specific hypotheses from the model for testing BDD patients in comparison with: (i) patients with "real" disfigurements who seek cosmetic surgery; (ii) subjects with "real" disfigurements who are emotionally well adjusted; and (iii) healthy controls without any defect. There have been no randomised controlled trials of treatment for BDD and therefore the model has clear implications for the development of cognitive behavioural therapy. This was evaluated in a pilot controlled trial. Nineteen patients were randomly allocated to either cognitive behaviour therapy or a waiting list control group over 12 weeks. There were no significant pre-post differences on any of the measures in the waiting list group. There were significant changes in the treated group on specific measures of BDD and depressed mood. Cognitive behaviour therapy should be further evaluated in a larger controlled trial in comparison with another psychological treatment such as interpersonal therapy and pharmacotherapy.

Adult↗
PubMed1996

Development of central 5-HT2A receptor radioligands for PET: comparison of [3H]RP 62203 and [3H]SR 46349B kinetics in rat brain.

[3H]RP 62203 and [3H]SR 46349B binding were assessed in rat brain after intravenous (iv) injection. The distribution of specific binding of each radioligand corresponded to the known distribution of 5-HT2A receptor sites. The maximum signals (counts/g tissue over counts/g cerebellum) given by [3H]RP 62203 and [3H]SR 46349B were 9.0 +/- 0.9 at 60 min and 3.2 +/- 0.3 at 30 min, respectively, in frontopolar cortex. Specific binding was quantified using a reference-tissue compartment model. RP 62203 appears to be more suitable than SR 46349B for development as a PET radioligand on the basis of its higher receptor specific signal.

Animals↗
PubMed1996

Generalized melanosis caused by melanoma of the rectum.

Only 29 cases of generalized melanosis caused by melanoma have been described in the English-language literature since the beginning of this century. This is the first reported case in which the primary site of melanoma was the mucosal surface of the rectum and melanosis was a presenting sign of the disease. Generalized melanosis carries a dismal prognosis; none of the reported patients lived beyond 1 year after the onset of pigmentation.

Fatal Outcome↗
PubMed1996

Human papillomavirus investigation of patients with cervical intraepithelial neoplasia 3, some of whom progressed to invasive cancer.

The major objective of the study was to determine if the contrasting frequencies (1.5% vs. 22%) of progression of cervical intraepithelial neoplasia (CIN) 3 lesions to invasive cervical carcinoma in two groups of patients in a previously published study from New Zealand had a virologic basis. Archival tissues on which the original diagnosis of CIN 3 was made were examined. Paraffin sections of 81 CIN 3 lesions from each group were tested for the presence of human papillomavirus (HPV)-6, -11, -16, and -18 DNA sequences by a combination of in of in situ hybridization for viral transcripts and polymerase chain reaction for viral DNA. The virologic profiles of the two groups were similar; HPV-16 and HPV-18 were identified, respectively, in 62% and 6% of CIN 3 lesions of group 1 and in 60% and 2% of CIN 3 lesions of group 2. additional tissues were examined for 17 women of group 2, who progressed from CIN 3 invasive cancer. Progression to invasive cancer was not associated with infection with specific HPV types. It is concluded that the contrasting frequencies of progression to invasive carcinoma in two groups of New Zealand women were not attributable to differences in HPV type distribution in the original CIN 3 lesions of these two groups.

Adult↗
PubMed1996

Body dysmorphic disorder. A survey of fifty cases.

BACKGROUND: Body dysmorphic disorder (BDD) consists of a preoccupation with an 'imagined' defect in appearance which causes significant distress or impairment in functioning. There has been little previous research into BDD. This study replicates a survey from the USA in a UK population and evaluates specific measures of BDD. METHOD: Cross-sectional interview survey of 50 patients who satisfied DSM-IV criteria for BDD as their primary disorder. RESULTS: The average age at onset was late adolescence and a large proportion of patients were either single or divorced. Three-quarters of the sample were female. There was a high degree of comorbidity with the most common additional Axis l diagnosis being either a mood disorder (26%), social phobia (16%) or obsessive-compulsive disorder (6%). Twenty-four per cent had made a suicide attempt in the past. Personality disorders were present in 72% of patients, the most common being paranoid, avoidant and obsessive-compulsive. CONCLUSIONS: BDD patients had a high associated comorbidity and previous suicide attempts. BDD is a chronic handicapping disorder and patients are not being adequately identified or treated by health professionals.

Adult↗
PubMed1994

Synthesis of the enantiomers of [N-methyl-11C]PK 11195 and comparison of their behaviours as radioligands for PK binding sites in rats.

The enantiomers of [N-methyl-11C]PK 11195, a radioligand for PET studies of PK (peripheral benzodiazepine) binding sites, have been prepared from the newly synthesized N-desmethyl-enantiomers by 11C-methylation with N.C.A. [11C]iodomethane. The brain uptake and retention of each enantiomer was compared with that of the racemic radioligand after i.v. administration into normal rats and into rats with focal cortical lesions. No significant differences in the uptakes of the enantiomers were observed in regions devoid of PK binding sites. However, the R-enantiomer was retained to a significantly greater extent than the S-enantiomer in olfactory bulbs-tubercles, which contain some PK binding sites, and also in 9-day-old focal cortical lesions, which are greatly enriched in PK binding sites associated with macrophage infiltration. The observed differences are consistent with the approximately 2-fold greater affinity of the R-enantiomer for PK binding sites reported in vitro and imply that the use of this enantiomer would have advantages over the use of the racemate currently used for PET studies.

Animals↗
PubMed1993

Can men be trusted? A comparison of pregnancy histories reported by husbands and wives.

Agreement between pregnancies and pregnancy outcomes reported by husbands and wives was assessed in a sample of 857 couples interviewed between June 1989 and July 1990. The respondents were men employed in a semiconductor manufacturing plant in Burlington, Vermont, and their wives. The wives' reports were used as the standard against which the husbands' reproductive histories were evaluated. Measures included sensitivity, specificity, and percentage of agreement. Reports were considered to be congruent if an outcome reported by the husband agreed with the outcome reported by the wife within a period of +/- 6 months. Although men and women reported similar numbers of livebirths (1,478 and 1,500, respectively), men tended to misreport the timing of events; therefore, complete agreement on the numbers and dates of births was only 88.5%. Men also misreported the prevalence of low birth weight (sensitivity, 74%). Specificity was poorer for the younger (< 35 years) and less educated (< or = 12 years) respondents. Husbands' reports of spontaneous abortions had lower sensitivity (71.2%) than their reports of livebirths, particularly among the better educated (66.9%). Induced abortions were frequently omitted by the husbands (sensitivity, 35.1%), and events such as stillbirths or tubal pregnancies were too few in number to permit meaningful analysis. It is concluded that husbands' misreporting of their wives' reproductive histories may be substantial and sufficient to compromise the validity of epidemiologic studies. It would, therefore, be prudent to avoid the use of husbands as proxy informants of their wives' reproductive histories.

Adult↗
PubMed1993

Radioligands for PET studies of central benzodiazepine receptors and PK (peripheral benzodiazepine) binding sites--current status.

The status of the radiochemical development and biological evaluation of radioligands for PET studies of central benzodiazepine (BZ) receptors and the so-called peripheral benzodiazepine binding sites, here discriminated and referred to as PK binding sites, is reviewed against current pharmacological knowledge, indicating those agents with present value and those with future potential. Practical recommendations are given for the preparation of two useful radioligands for PET studies, [N-methyl-11C]flumazenil for central BZ receptors, and [N-methyl-11C]PK 11195 for PK binding sites. Quality assurance and plasma metabolite analysis are also reviewed for these radioligands and practical recommendations are given on methodology for their performance.

Animals↗
PubMed1992

Antibodies to HPV-16 E6 and E7 proteins as markers for HPV-16-associated invasive cervical cancer.

Transforming proteins E6 and E7 of human papillomaviruses (HPVs) are consistently expressed in HPV-associated cervical cancers. In ELISA with four HPV-16 E6-E7 peptides, patients with HPV-16-associated invasive cervical cancer (group 1) had a greater seroreactivity than all other groups, which included patients with HPV-16-associated cervical intraepithelial neoplasia, invasive cervical cancer patients without HPVs, and unaffected controls. A larger proportion of group 1 sera, as compared to sera of all other groups, was reactive with at least one peptide (49% vs 17-27%), and with two or more peptides (22% vs 0-6%). A clear difference between group 1 and all other groups was also found for high ELISA absorbance values to at least one peptide (22% vs 0-8%). This high seroreactivity of group 1 sera was confirmed by a radioimmunoprecipitation assay with in vitro transcribed and translated HPV-16 E7 protein. Sera from 50% of group 1 but only 3% of controls were reactive in this test. Antibodies to HPV-16 E6 and E7 proteins appear to be virus-specific and disease state-specific markers of HPV-associated cervical cancer.

Amino Acid Sequence↗
PubMed1992

A comparison of risk factors in juvenile-onset and adult-onset recurrent respiratory papillomatosis.

The clinical triad of a firstborn delivered vaginally to a young (teenage) mother has been previously noted among juvenile onset recurrent respiratory papillomatosis (JO-RRP) patients. This study was based on a questionnaire survey of JO-RRP patients, adult onset recurrent respiratory papillomatosis (AO-RRP) patients, and juvenile and adult controls. The survey results revealed that the complete or partial triad was observed in 72% of JO-RRP patients, 36% of AO-RRP patients, 29% of juvenile controls, and 38% of adult controls. As compared with juvenile controls, JO-RRP patients were more often firstborn (P less than .05), delivered vaginally (P less than .05), and born to a teenage mother (P less than .01). Among adult participants, AO-RRP patients reported more lifetime sex partners (P less than .01) and a higher frequency of oral sex (P less than .05) than reported by adult controls. AO-RRP and JO-RRP appear to have distinguishable epidemiologic features indicating that the mode of human papillomavirus (HPV) transmission is different in these two disorders.

Adolescent↗
PubMed1991

Asymmetric synthesis of a precursor for the automated radiosynthesis of S-(3'-t-butylamino-2'-hydroxypropoxy)-benzimidazol-2-[11C]one (S-[11C]CGP 12177) as a preferred radioligand for beta-adrenergic receptors.

S-[1-(2,3-Diaminophenoxy)]-3'-(N-t-butylamino)propan-2'-ol has been synthesized in three steps from 2,3-dinitro-phenol and the chiral auxiliary, S-glycidyl-3-nitrobenzenesulphonate, to provide a precursor for labelling S-(3'-t-butylamino-2'-hydroxypropoxy)-benzimidazol-2-one (S-CGP 12177) with the short-lived positron-emitting radionuclide, carbon-11 (t 1/2 = 20.4 min; beta+ = 99.8%). Reaction of the diamine with [11C]phosgene, itself derived from no-carrier-added cyclotron-produced [11C]methane, provides radiochemically and chemically pure S-[carbonyl-11C]CGP 12177 in greater than 95% enantiomeric excess after HPLC. Automated apparatus is described for safely producing up to 5.9 GBq (160 mCi) of S-[11C]CGP 12177 with high sp. act. (20-40 GBq/mu mol or 0.54-1.08 Ci/mu mol) in a form suitable for human intravenous injection at only 30 min from the end of radionuclide production. S-[11C]CGP 12177 is preferred to the formerly described racemate as a radioligand for the study of beta-adrenergic receptors in vivo by positron emission tomography.

Adrenergic beta-Antagonists↗