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K Shah

Publications and source records attributed to K Shah.

At least 19 recordsLinked to original sources
PubMed1992

Detection of HPV-16 in cell lines and cervical lavage specimens by a polymerase chain reaction-enzyme immunoassay assay.

A gene amplification method that combines the polymerase chain reaction with detection of amplified DNA in a solution hybridization/enzyme immunoassay (PCR-EIA) was developed for HPV-16 DNA. Samples were amplified with primers for the E7-E1 region of HPV-16. Amplified DNA products were identified and quantitated by hybridization in solution with a biotinylated RNA probe. Labeled DNA/RNA hybrids were measured semiquantitatively in an enzyme immunoassay using solid phase anti-biotin antibody and liquid phase B-d-galactosidase labeled monoclonal antibody against DNA-RNA hybrids. Enzyme bound to the solid phase was quantitated with a fluorogenic substrate. The assay was linear over 2 log10 dilutions of SiHa cells and the detection limit was three copies of HPV-16 genome. The sensitivity of PCR-EIA for detection of PCR amplified products compared favorably with slot and Southern blots using a 32P-labeled RNA probe. The assay was used to assess HPV-16 infection of uterine cervix in women attending a clinic for sexually transmitted diseases. Twenty-one of the 81 specimens (25.9%), obtained by cervicovaginal lavage, were positive for HPV-16 by PCR-EIA. The assay provides a convenient means to objectively measure HPV DNA amplified with PCR.

Animals↗
PubMed1992

Capsazepine: a competitive antagonist of the sensory neurone excitant capsaicin.

1. Capsazepine is a synthetic analogue of the sensory neurone excitotoxin, capsaicin. The present study shows the capsazepine acts as a competitive antagonist of capsaicin. 2. Capsazepine (10 microM) reversibly reduced or abolished the current response to capsaicin (500 nM) of voltage-clamped dorsal root ganglion (DRG) neurones from rats. In contrast, the responses to 50 microM gamma-aminobutyric acid (GABA) and 5 microM adenosine 5'-triphosphate (ATP) were unaffected. 3. The effects of capsazepine were examined quantitatively with radioactive ion flux experiments. Capsazepine inhibited the capsaicin (500 nM)-induced 45Ca2+ uptake in cultures of rat DRG neurones with an IC50 of 420 +/- 46 nM (mean +/- s.e.mean, n = 6). The 45Ca2+ uptake evoked by resiniferatoxin (RTX), a potent capsaicin-like agonist was also inhibited. (Log concentration)-effect curves for RTX (0.3 nM-1 microM) were shifted in a competitive manner by capsazepine. The Schild plot of the data had a slope of 1.08 +/- 0.15 (s.e.) and gave an apparent Kd estimate for capsazepine of 220 nM (95% confidence limits, 57-400 nM). 4. Capsazepine also inhibited the capsaicin- and RTX-evoked efflux of 86Rb+ from cultured DRG neurones. The inhibition appeared to be competitive and Schild plots yielded apparent Kd estimates of 148 nM (95% confidence limits, 30-332 nM) with capsaicin as the agonist and 107 nM (95% confidence limits, 49-162 nM) with RTX as agonist. 5. A similar competitive inhibition by capsazepine was seen for capsaicin-induced [14C]-guanidinium efflux from segments of adult rat vagus nerves (apparent Kd = 690 nM; 95% confidence limits, 63 nM-1.45 microM). No significant difference was noted in the apparent Kd estimates for capsazepine in assays on cultured DRG neurones and vagus nerve as shown by the overlap in the 95% confidence limits.6. Capsazepine, at concentrations up to 1O microM, had no significant effects on the efflux of 86Rb+ from cultured DRG neurones evoked either by depolarization with high (50 mM) K' solutions or by acidification of the external medium to pH 5.0-5.6. Similarly capsazepine had no significant effect on he depolarization (50 mM KCl)-induced efflux of [14C]-guanidinium from vagus nerve preparations.7. Ruthenium Red was also tested for antagonism against capsaicin evoked ['4C]-guanidinium release from vague nerves and capsaicin induced 45Ca2" uptake in cultures of DRG neurones. In contrast to capsazepine the inhibition by Ruthenium Red (10-500nM in DRG and 0.5-10microM in vagus nerve experiments) was not consistent with a competitive antagonism, but rather suggested a more complex,non-competitive inhibition.

Adenosine Triphosphate↗
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

Polymerase chain reaction identification of human papillomavirus DNA in CO2 laser plume from recurrent respiratory papillomatosis.

Human papillomavirus (HPV) DNA was identified in the plume produced during CO2 laser vaporization of respiratory tract papillomata. The plume produced from CO2 vaporization was collected on Gelfoam pledgets that were affixed to suction tips evacuating the vapor plume from the operative field. The Gelfoam pledgets were snap frozen in liquid nitrogen, processed, and examined for HPV-6 and HPV-11 DNA by a polymerase chain reaction technique. Tissue and vapor-plume specimens were collected from 22 patients undergoing CO2 laser excision of laryngeal lesions. Seven patients had adult-onset recurrent respiratory laryngeal papillomatosis (RRP), 12 had juvenile-onset RRP, two had laryngeal carcinoma, and one had nonspecific laryngitis. HPV-6 or HPV-11 was identified in 17 of 27 vapor-plume specimens from RRP and in none of three from non-RRP lesions. All but one RRP tissue specimen contained HPV-DNA, and none of the non-RRP tissues contained HPV-DNA. When HPV was present in vapor, the same HPV type was found in the corresponding tissue specimen. Identification of HPV-DNA in the laser plume raises concern regarding potential risks from exposure to the plume--particularly to the endoscopic surgeon and the operating team. The practical concerns and effectiveness of the plume scavenging systems are discussed.

Air Microbiology↗
PubMed1991

Relative and absolute reinforcement frequency as determinants of choice in concurrent variable interval schedules.

Rats were trained under concurrent schedules consisting of two equal variable interval component schedules providing sucrose solutions of different concentrations (0.6 M, 0.2 M; 50 microliters in each case) as the reinforcers. The mean interreinforcement interval specified by the schedules was varied from 10 to 640 sec. Absolute response rate in each component was an increasing hyperbolic function of reinforcement frequency. Relative response rate and relative time allocation revealed a consistent preference for the more concentrated solution; neither measure of preference was systematically related to reinforcement frequency. The results are consistent with Baum and Rachlin's (1969) extension of the matching law, and with a derivation of the matching law from the hyperbolic relation between absolute response rate and reinforcement frequency in variable interval schedules (Herrnstein, 1970).

Animals↗
PubMed1990

Interaction between antidepressants and d-amphetamine on variable-interval performance.

Four experiments were carried out investigating the interactions between some antidepressant drugs (imipramine, desipramine, fluvoxamine, trazodone (4 and 8 mg/kg) and d-amphetamine (0.1-3.2 mg/kg) on operant behaviour maintained under a variable-interval 80-s schedule of sucrose reinforcement; each experiment employed 12 rats. d-Amphetamine exerted a dose-related suppressant effect on response rate. Imipramine and desipramine given alone had no effect on response rate, whereas fluvoxamine (both doses) and the higher dose of trazodone produced significant increases in response rate. Pretreatment with imipramine, desipiramine or fluvoxamine significantly potentiated the suppressant effect of d-amphetamine on responding; pretreatment with trazodone had no significant effect. The potentiating effect of imipramine and desipramine may be related to their well known uptake blocking actions. The fact that fluvoxamine, a selective inhibitor of 5-hydroxytryptamine (5HT) uptake, also potentiated the effect of d-amphetamine suggests that the suppressant effect of d-amphetamine on operant behaviour may involve 5HT as well as catecholamine release. The lack of effect of trazodone may reflect its failure to influence uptake mechanisms. On the basis of a formal model couched in terms of Herrnstein's (1970) equation, it is suggested that imipramine, desipramine and fluvoxamine may have enhanced d-amphetamine's ability to reduce response capacity; it is suggested that the data do not provide evidence for an interaction between the antidepressants and the putative "motivation-enhancing" effect of d-amphetamine.

Animals↗
PubMed1990

Human papillomavirus in squamous cell carcinoma, leukoplakia, lichen planus, and clinically normal epithelium of the oral cavity.

Tissue specimens of carcinoma, leukoplakia, and clinically normal epithelium obtained at sites separate from the lesions were examined for the presence of human papillomavirus (HPV). Twenty-two paraffinized specimens of previously diagnosed oral lichen planus were also studied. The carcinoma and leukoplakia specimens were examined by Southern transfer hybridization and reverse blot hybridization; specimens HPV-positive by Southern hybridization were additionally examined by in situ hybridization and an immunoperoxidase technique. The lichen planus specimens were examined by in situ hybridization and immunoperoxidase techniques only. The HPV identification rates were in the range reported in previous studies, and the detection rates were similar for carcinoma, leukoplakia, histologically normal epithelium, and lichen planus. The clinical significance of HPV presence in carcinoma, leukoplakia, and lichen planus was not evaluable because of the short duration of follow-up.

Adult↗
PubMed1990

Electrocardiographic J waves after resuscitation from cardiac arrest.

A patient was monitored prior to, during, and after cardiac arrest with a Holter monitor and an electrocardiograph. The arrest occurred without any premonitory signs on the ECG. At the onset of the arrest, torsades de pointes ventricular tachycardia occurred, which quickly degenerated into ventricular fibrillation. After a successful second defibrillation, the patient developed Osborn waves, which subsided within a few minutes.

Coronary Artery Bypass↗
PubMed1989

Anxiogenic-like effects of mCPP and TFMPP in animal models are opposed by 5-HT1C receptor antagonists.

1-(3-chlorophenyl)piperazine (mCPP) and 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP) (0.1-1.0 mg/kg) reduce total interaction time in a rat social interaction test under low light familiar conditions and its following components; grooming, following, crawling over, fighting, sniffing. Locomotion was only reduced by the highest dose of mCPP. mCPP also reduced activity in the light but not total locomotion in a light/dark transition test. These results suggest that mCPP (and TFMPP) are anxiogenic but not sedative in these tests. The effect of mCPP on social interaction was blocked by three antagonists which share a high affinity for 5-HT1C and 5-HT2 receptors: mianserin, cyproheptadine and metergoline but not by the 5-HT2 antagonists ketanserin or ritanserin or the 5-HT1A and 5-HT1B antagonists cyanopindolol and (-)-propranolol. It was prevented by a low (0.05 mg/kg) but not by a high (1.0 mg/kg) dose of ICS 205,930 a specific 5-HT3 antagonist reported to be anxiolytic at low doses. It was also prevented by chronic pretreatment with the anxiolytic drug chlordiazepoxide. These results argue for an anxiogenic action of mCPP mediated by 5-HT1C receptors. Since the chronic chlordiazepoxide pretreatment did not prevent the hypolocomotion or hypophagia induced by mCPP at high dosage (5 mg/kg) these latter effects are unlikely to be secondary to anxiety.

Animals↗
PubMed1989

The role of vitamins in the etiology of cervical neoplasia: an epidemiological review.

Diet may act as a cofactor in the development of cancer of the cervix. A consistent correlation exists between low tissue concentrations, low serum level, and low intake of vitamin A, beta-carotene, vitamin C, or folic acid and an increased prevalence of cervical neoplasia. A moderate effect is seen in clinical trials with vitamin treatment of cervical intraepithelial neoplasias. The studies reviewed here were not consistent especially in the choice of controls and methods for the assessment of dietary and confounding factors. Proper morphologic identification of cervical intraepithelial neoplasia was not always achieved. Longitudinal and prospective cohort studies using more reliable methods for diet monitoring may be valuable for future research in this field.

Ascorbic Acid Deficiency↗
PubMed1989

The value to the anesthesia-surgical care team of the preoperative cardiac consultation.

A retrospective analysis of 202 consultations for preoperative cardiology evaluation was conducted. The most common problems generating the consultation were: (1) abnormal electrocardiogram, 45 patients; (2) chest pain, 36 patients; (3) history of myocardial infarction, 27 patients; (4) dysrhythmia, 25 patients; and (5) hypertension, 23 patients. The most common diagnoses by the consultants were: (1) arteriosclerotic heart disease, 46 patients; (2) angina, 20 patients; and (3) hypertension, 40 patients. Mitral valve prolapse was the most common valvular disease (18 patients). Of the consultation requests, 108 asked for an evaluation; 79 asked for a "clearance"; 9 did not specifically ask for anything; and 6 asked a highly specific question. Most consultations provided a diagnosis (96%), addressed the problem (80%), and provided logical recommendations (96%). A minority of the consultations "cleared" a patient (28%), provided for follow-up care (41%), or suggested intraoperative monitoring techniques (41%). Out of the 189 patients who eventually had surgery, 137 patients had no change in their preoperative therapy, while 52 patients had a change in preoperative therapy. There was no difference in the incidence of complications between these two groups. An important finding was that 15% of the study group (31 patients) had disease processes (hypertension and angina) that were newly diagnosed by the consultant or felt to be not adequately treated before the consultation. It is concluded that few requesting anesthesiologists and surgeons ask for clarification of a specific problem, while most responses from the cardiology consultants provided necessary information. In addition, the preoperative cardiac consultation was found to identify medical conditions requiring long-term care and follow-up.

Adolescent↗