Electrocardiographic lead systems.
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Electrocardiography↗
Biomedical subjects
K Shah
Publications and source records attributed to K Shah.
"Nutcracker esophagus": a case of false-negative radionuclide esophageal transit study.
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Adult↗
DSP4 and Herrnstein's equation: further evidence for a role of noradrenaline in the maintenance of operant behaviour by positive reinforcement.
The effect of the selective noradrenaline neurotoxin DSP4 on steady-state operant behaviour was examined using a quantitative behavioural paradigm based on Herrnstein's (1970) equation, which defines a hyperbolic relationship between steady-state response rate and reinforcement frequency in variable-interval schedules. Eleven rats received injections of DSP4 (two doses of 50 mg/kg, intraperitoneally), and 12 rats received injections of the vehicle alone. The rats were trained to steady state in a series of six variable-interval schedules of sucrose reinforcement, affording scheduled reinforcement frequencies of 4-360 reinforcers per hour. Herrnstein's equation was fitted to the data obtained from each rat and to the averaged data obtained from the two groups. The value of KH (the parameter expressing the reinforcement frequency needed to maintain the half-maximal response rate) was higher in the DSP4-treated rats than in the control rats; the value of Rmax (the parameter expressing the maximum response rate) did not differ significantly between the two groups. At the end of the behavioural experiment the rats were sacrificed for determination of the concentrations of catecholamines in the brain by high-performance liquid chromatography. The levels of noradrenaline in the parietal cortex, hippocampus and cerebellum of the DSP4-treated rats were less than 20% of those of the control rats. The results provide further evidence that central noradrenergic neurones are involved in the maintenance of operant behaviour by positive reinforcement.
Animals↗
Reduction in mortality from cardiac causes in goldman class IV patients.
In 1977, Goldman et al evaluated cardiac patients for non-cardiac operations and showed a high incidence of cardiac death in high-risk cardiac patients (Goldman class IV). The present study was designed to prospectively evaluate the incidence of cardiac death as well as overall mortality in 49 patients belonging to Goldman class IV at the present time. Four patients of 49 (8.2%) died of cardiac causes, and seven other patients died of non-cardiac causes. Thus, the overall mortality rate was 22.4% (11/49). There has been a marked reduction in cardiac mortality from 56% in Goldman et al's 1977 data to 8.2% in the present data. All of the developments and advances in patient care over the past 10 years probably contributed to this reduction in mortality from cardiac causes.
Adult↗
The predominance of human papillomavirus type 16 in vulvar neoplasia.
Southern transfer analysis for human papillomavirus genomic sequences was conducted on 152 vulvar and vaginal tissue specimens obtained from 86 patients. Histopathologic diagnoses included condyloma acuminatum, intraepithelial neoplasia, and invasive cancer. In six patients, lesions of more than one pathologic type were identified. Vaginal lesions constituted less than 5% of tissues examined. Distribution of lesions was as follows: condyloma, 93 lesions from 57 patients; intraepithelial neoplasia, 47 lesions from 29 patients; and invasive carcinoma, 12 lesions from six patients. Seventy-five percent of the patients were white. The mean age of the patients increased from 25 years for condyloma to 38 years for vulvar intraepithelial neoplasia III to 56 years for invasive cancer. A viral diagnosis was made in 81% of condylomas, 84% of vulvar intraepithelial neoplasia III, and 58% of invasive carcinomas. Distribution of viral types differed markedly for the various histopathologies. Types 6/11 accounted for 77% of condylomas and 0% of vulvar intraepithelial neoplasia III. Type 16 was recovered from 12% of condylomas and 81% of vulvar intraepithelial neoplasia III. Type 18 was identified in a small proportion in both categories; type 31 was seen in a few vulvar intraepithelial neoplasia III lesions. In invasive carcinomas, type 16 was the predominantly identified virus. Papillomavirus type 16 emerges as the dominant oncogenic virus in vulvar neoplasms. Its presence in a large percentage of condylomas raises the issue of an "atypical condyloma" as a precursor of neoplasia.
Adult↗
Search for human papillomaviruses in normal, hyperplastic, and neoplastic endometria.
Twenty-eight endometria, including seven normal, five hyperplastic, and 16 neoplastic tissues, were analyzed with the Southern blot hybridization technique for their possible association with human papillomaviruses (HPVs). Human papillomavirus probes with types 6/11, 16, 18, and 31 failed to identify HPV DNA in any of these tissues. The findings suggest that the endometrium is not a usual target for HPV infection, and that HPV is not likely to be a carcinogenic factor in the development of endometrial carcinoma.
Adenocarcinoma↗
High prevalence of genital tract papillomavirus infection in female adolescents.
To investigate clinical condyloma, abnormal cervical cytologic findings, and evidence of human papillomavirus infections, 89 adolescent girls were examined. Cellular DNAs extracted from exfoliated cervical cells were examined for human papillomavirus genomic sequences by Southern transfer hybridization using 32P-labeled human papillomavirus DNA probes. Human papillomavirus sequences were detected in 12 (13%) young women, abnormal cytologic specimens in 21 (24%), and vulvar condylomas in 12 (13%). The human papillomavirus types identified included HPV-6/11 (four instances), which is known to be associated with benign lesions, and HPV-16, -18, and -31 (eight instances) which are considered to have oncogenic potential. Two young women were infected with both HPV-16 and -31. Human papillomavirus sequences were found in 48% of the young women with abnormal cytologic findings and in 3% of patients with normal cytologic findings (P less than .0001). Condylomatous changes in the cervical smear were associated with the presence of HPV-6/11 and mild dysplasia with the presence of HPV-16, -18, and -31. The presence of vulvar condylomas correlated with condylomatous changes in the cervical smear and with the recovery of HPV-6/11 from the cervical epithelium. The results indicate that the prevalence of human papillomavirus infections in this population is high and that a majority of the infections are with viruses associated with lower genital tract malignancies.
Adolescent↗
Thrombocytopenia and human immunodeficiency virus in children.
Thrombocytopenia occurs in 13% of children with symptomatic human immunodeficiency virus (HIV) infection. The clinical and laboratory course of 19 children infected with HIV with thrombocytopenia is described. Bone marrow aspirates showed normal to increased numbers of megakaryocytes. Levels of antiplatelet antibodies were increased in 80% of the children and circulating immune complexes were found in 74%. Clinically significant hemorrhage leading to anemia occurred in five patients, and CNS bleeding led to a fatal outcome in an additional three children. Spontaneous remission of thrombocytopenia occurred in three of the 19 subjects. High-dose IV gamma-globulin was effective in increasing the platelet counts of six of 15 patients (40%) but resulted in a sustained remission in only one subject. Oral prednisone was effective in increasing the platelet count of two thirds of those whose platelet counts could not be controlled by IV gamma-globulin. Bleeding manifestations were eliminated in all patients whose platelet counts increased significantly. Of the 11 children whose counts increased either spontaneously or as a result of therapy, eight remain alive (72%). In contrast, all of the eight patients whose platelet counts did not improve have died. Thrombocytopenia in children with HIV disease is engendered by immune mechanisms and is a major cause of morbidity and mortality. High-dose IV gamma-globulin and/or corticosteroids are temporarily effective in increasing the platelet count and reducing bleeding in about half of thrombocytopenic patients and are recommended for use. The ability to respond to therapy correlates with improved survival.
Acquired Immunodeficiency Syndrome↗
Topographic study of cervical condyloma and intraepithelial neoplasia.
In this study of 101 cervical conization specimens, the location and the size of condyloma and intraepithelial neoplasia (dysplasia and carcinoma in situ) were mapped using the last endocervical gland as the marker for the original squamocolumnar junction. Condylomatous changes were identified in 85% of cervices affected by the intraepithelial neoplasia, and were in direct contact with 68% of intraepithelial neoplasms. The proximal location of intraepithelial neoplasia in relation to the condyloma can be explained by the occurrence of neoplasia just proximal to the condyloma and subsequent expansion of neoplasia towards the cervical canal. This study adds topographic evidence linking cervical condyloma to the development of intraepithelial neoplasia.
Carcinoma in Situ↗
Human papillomavirus type 16 in intraepithelial neoplasia (bowenoid papulosis) and coexistent invasive carcinoma of the vulva.
Tissues from two cases of bowenoid papulosis of the vulva with coexistent invasive squamous cell carcinoma were evaluated for the presence of human papillomaviruses (HPVs) and for nuclear DNA content. In both cases, HPV type 16 and nuclear aneuploidy were found in bowenoid papulosis as well as in invasive carcinoma. Patterns of hybridization suggested that the viral genome was integrated into the cellular genome in both bowenoid papulosis tissues as well as in invasive carcinoma tissues. These observations suggest that lesions designated as bowenoid papulosis may have invasive cancer potential. The term vulvar intraepithelial neoplasia seems to be more appropriate for HPV-16-containing aneuploid, intraepithelial lesions of the vulva.
Adult↗
Recurrent respiratory papillomatosis. Clinical overview and management principles.
Recurrent respiratory papillomatosis is an uncommon clinical disorder of respiratory epithelium caused by HPV. It shares the identical viral etiology with genital condyloma and in all likelihood is transmitted at the time of birth (juvenile-onset disease) and through intimate sexual contact (adult-onset disease). The recent establishment of viral etiology modifies our concepts regarding the nature of the disease, its epidemiology, and its treatment.
Adult↗
Human papillomaviruses in women with a history of abnormal Papanicolaou smears and in their male partners.
Human papillomavirus infection of the genital tract was identified by the filter in situ hybridization test. Exfoliated cervical cells were tested separately for the prevalence of human papillomavirus 6/11 and 16/18. Human papillomavirus deoxyribonucleic acid (DNA) was identified in 70 and 92% of specimens of U.S. and West German women, respectively, who showed concurrent cytologic and colposcopic abnormalities, and in 50 and 54% of women, respectively, who showed neither cytologic nor colposcopic abnormalities at the time of examination. In the cytologic categories of condyloma, mild to moderate dysplasia (cervical intraepithelial neoplasia I/II), and severe dysplasia-carcinoma in situ (cervical intraepithelial neoplasia III), the overall DNA detection rate of human papillomavirus 6/11 and 16/18 varied between 75 and 83%; but human papillomavirus 16/18 was recovered relatively more frequently from the more severe lesions. Forty-eight West German women were monitored cytologically over a period of three to 24 months; progression to carcinoma in situ (cervical intraepithelial neoplasia III) was correlated with initial isolation of human papillomavirus 16/18. The vagina and vestibule were found to be frequent sites of human papillomavirus infection with the same virus type as in the cervix. In an investigation of male partners of 40 human papillomavirus-positive women, human papillomavirus was identified in exfoliated cells from 26; in 19 instances, the males harbored the same human papillomavirus types as their female partners.
Autoradiography↗
Association of human papillomavirus type 16 with neoplastic lesions of the vulva and other genital sites by in situ hybridization.
The authors examined paraffin sections from 85 genital tract tissues from 49 cases for the presence of human papillomavirus (HPV) Types 6/11, 16, and 18 by stringent in situ hybridization using 35S-labeled viral DNA probes, and for viral capsid antigen by the immunoperoxidase test. The cases, selected mostly on the basis of vulvar pathology, were distributed as follows: early neoplasia (Group I, 6 cases); early neoplasia with viral cytopathic effect (CE) (Group II, 24 cases); and papillomavirus infection (PVI) (Group III, 19 cases). Available tissues from all affected sites were examined when the disease was multicentric. One or more viral DNAs were identified in 58% of 77 tissues from Groups II and III and in 2 of 8 tissues from Group I. HPV-6/11, HPV-16 and HPV-18 DNAs were detected, respectively, in 25, 24, and 2 tissues; 3 tissues were infected simultaneously with either two or three viruses. Viral DNA was identified at more than one site in 14 of 30 DNA-positive patients; in 10 of these, a single type was detected at all sites in the same patient. The viral DNA was localized mostly in areas showing viral cytopathology. The presence of HPV-16 correlated with neoplasia. HPV-16 DNA was identified in the 2 virus-positive tissues showing neoplasia, in 17 of 20 (85%) of the DNA-positive tissues showing neoplasia with CE, and in 5 of 25 (20%) of the DNA-positive tissues showing PVI. Conversely, HPV-6/11 was found in 25% of the DNA-positive tissues showing neoplasia with CE and in 80% of the cases of PVI. An HPV genome was identified in neoplastic cells in 14 instances; in all but 1 case, the genome was HPV-16. The association of HPV-16 with neoplasia was seen for both vulvar and cervical lesions. Viral antigen was detected in 83% of lesions associated with HPV 6/11 and in 62% of lesions associated with HPV-16.
Adult↗
Condylomata acuminata arising in a neovagina.
A case is reported in which condylomata acuminata arose in a McIndoe neovagina. Histopathologic and virologic evidence are provided to support the characterization of these lesions as benign warty processes secondary to human papillomavirus-6. Factors influencing viral site specificity are discussed.
Adult↗
Recurrent infiltrating lipoma of the head and neck. Case report and literature review.
Lipomatous tumors with intramuscular infiltration are uncommon in the head and neck. Oral lipomas have been recorded in the literature; however, infiltration and recurrence have rarely been documented. We describe a case of an oral lipoma that did not have microscopic characteristics of malignancy, lipoblastomatosis, or atypia, but which showed intramuscular invasion and recurred twice after surgery. Although certain characteristics distinguish our case from congenital lipomatosis, the clinical picture is quite similar. Lipomas with intramuscular invasion uniformly tend to recur when they are not widely resected, whether in the trunk and extremities or in the head and neck. These lesions can rapidly enlarge and infiltrate local tissues, and they require wide resection with an attempt at preservation of important structures. Preoperatively, computed tomographic analysis allows a lipoma to be diagnosed by its low attenuation, and a grossly infiltrating tumor can be distinguished from the ordinary well-encapsulated lesion.
Child, Preschool↗
Methods of comparing pharmacokinetics of slow release preparations: a comparison of "Theo-Dur" and "Phyllocontin" in patients with asthma.
The pharmacokinetics of two slow release theophylline preparations "Theo-Dur" (T) containing theophylline only and "Phyllocontin" (P) containing aminophylline have been compared in 12 patients with asthma. Each patient received both treatments in random order. The dose of treatment administered 12 hourly was increased or decreased to produce plasma theophylline concentrations of 10-20 mg/l at clinic visits normally 7 to 8 h after dosing. Pharmacokinetic studies were carried out after at least one week's treatment with this dose. After the first study day patients were crossed over to the second treatment at a dosage providing a similar amount of theophylline. They returned for a second study day after at least one week. Comparison of the dose corrected AUC, time to peak concentrations, within patient coefficients of variation (CV), number of concentration time points falling within 25% of Cmax and percentage fluctuations in plasma concentration showed no significant differences between the two preparations.
Adult↗
Esophageal cryptosporidiosis in a child with acquired immune deficiency syndrome.
Oral Candida and Candida esophagitis are common findings in patients with the acquired immune deficiency syndrome. The intestinal protozoan, Cryptosporidium, is known to cause gastrointestinal symptoms in these patients. We report a 2-yr-old child with acquired immune deficiency syndrome, who had oral candidiasis, dysphagia, and vomiting. Upper gastrointestinal endoscopy and esophageal biopsy led to a diagnosis of esophageal cryptosporidiosis. We recommend upper gastrointestinal endoscopy as a diagnostic tool in selected patients with acquired immune deficiency syndrome. This is in contradistinction to a previous report that concludes that endoscopy is not necessary in this setting.
Acquired Immunodeficiency Syndrome↗