Search PubMed⌕ Search

Biomedical subjects

R Smith

Publications and source records attributed to R Smith.

At least 1,009 records · Page 56Linked to original sources
PubMed1989

A synthetic peptide defines a serologic IgA response to a human papillomavirus-encoded nuclear antigen expressed in virus-carrying cervical neoplasia.

The growing awareness of the role of human papillomavirus (HPV) in cervical carcinoma has triggered a search for uncomplicated detection methods. To define a serologic response to HPV, we synthesized peptides based on sequences deduced from the genome of HPV type 16, the most common malignancy-associated type of HPV. One of these peptides reacted with IgA antibodies present in sera from 24 of 33 patients with cervical intraepithelial neoplasia or cervical carcinoma, whereas this peptide reacted with only 6 of 27 sera from individuals without cervical intraepithelial neoplasia. Immunoaffinity-purified human antipeptide IgA antibodies detected HPV-specific 58- and 48-kDa proteins in cervical carcinoma cell extracts and also detected a nuclear antigen in HPV-carrying cervical cancer cell lines and cervical intraepithelial neoplasia biopsied tissue. These antigens were also detected with mouse monoclonal and rabbit polyclonal antibodies to the same peptide. The results indicate that screening for infection with malignancy-associated types of HPV may be possible by simple synthetic peptide-based serology.

Antibodies, Neoplasm↗
PubMed1989

The mouse homolog of the hst/k-FGF gene is adjacent to int-2 and is activated by proviral insertion in some virally induced mammary tumors.

The fibroblast growth factor-related protooncogenes, int-2 and hst/k-FGF, are within 17 kilobase pairs of one another on mouse chromosome 7 and are in the same transcriptional orientation. Approximately 70% of tumors induced in BR6 mice by mouse mammary tumor virus have proviral insertions adjacent to the int-2 gene. We find that the murine homolog of the hst/k-FGF gene can also be transcriptionally activated by the insertion of mouse mammary tumor virus DNA either upstream or downstream of the gene. In most tumors, only one of these adjacent genes is activated, but in some cases both genes are expressed. One of the hst-expressing tumors also has a virally activated int-3 gene. At least five distinct cellular genes (int-1, -2, -3, -4, and hst/k-FGF) can therefore contribute, either singly or in concert, to the development of histologically indistinguishable mammary tumors in mice infected by mouse mammary tumor virus.

Animals↗
PubMed1989

Validity and reliability of the DSM-III criteria for posttraumatic stress disorder. Experience with a structured interview.

The DSM-III criteria for posttraumatic stress disorder (PTSD) were operationally defined for use in a structured interview. Acceptable interrater and test-retest reliabilities were shown; diagnostic validity was demonstrated relative to a standard diagnostic interview procedure; construct validity was shown in relation to a PTSD self-rating scale and to degree of combat exposure; the structured interview score correlated significantly with observer symptom scales for depression and anxiety.

Humans↗
PubMed1989

Aneurysm of the internal iliac vein as a rare source of pulmonary thromboembolism.

This is the first reported case of internal iliac vein aneurysm, manifested by recurrent pulmonary embolism. The case emphasizes the importance of searching for unusual sources of unexpected and unexplained pulmonary emboli. Venous aneurysms may have various manifestations and sequelae. Antecedent trauma and arteriovenous fistulas should be excluded.

Adult↗
PubMed1989

Cardiovascular responses to metipranolol and timolol eyedrops in healthy volunteers.

1. Intraocular pressure and cardiovascular responses to metipranolol 0.1% and 0.3% and timolol 0.25% eyedrops were measured in a balanced single dose placebo-controlled crossover study in eight healthy volunteers aged 34-58 years. 2. Timolol 0.25% and metipranolol 0.3% reduced intraocular pressure throughout the 6 h period of observation to a similar extent. Metipranolol 0.1% was marginally less effective, significantly reducing pressure up to 4 h only. 3. No drug treatment significantly altered resting heart rate or blood pressure. Timolol 0.25% significantly reduced exercise tachycardia (P less than 0.05), an effect which was not shown by metipranolol 0.1 or 0.3%. Exertional pain in the legs occurred more frequently after timolol 0.25% and metipranolol 0.3% than after metipranolol 0.1% or placebo eyedrops. 4. Octan-1-ol/pH 7.4 buffer distribution coefficients at 37 degrees C were found to be: metipranolol 5.19, timolol 0.84, indicating that metipranolol has an approximately 6-fold greater lipid solubility. 5. It is concluded that, by comparison with timolol, metipranolol in eyedrop concentrations up to 0.3%, despite its greater lipid solubility, reaches concentrations in the systemic circulation which are less likely to affect the heart.

Adult↗
PubMed1989

Characterisation of monoclonal antibodies to common protein epitopes on the cell surface of Streptococcus mutans and Streptococcus sobrinus.

Three monoclonal antibodies (MAb) were prepared against a cell surface antigen which cross-react between Streptococcus mutans (serotypes c, e and f) and Streptococcus sobrinus (serotypes d and g). Two of the MAb also recognise a determinant on the surface of Streptococcus cricetus (serotype a). The common antigen shared between S. mutans and S. sobrinus was demonstrated by Western blotting to be about 200 kD in size. This antigen is shared not only by the cell surfaces of serotypes a, c, d, e, f and g, but also by the major cell surface antigen of S. mutans of 185 kD and another of 150 kD. These MAb identify all but one mutans type of streptococci and can be utilised as analytical reagents.

Antibodies, Monoclonal↗
PubMed1989

Coronary artery disease, HDL cholesterol, and insulin-gene flanking sequences.

The relationship between coronary artery disease, HDL cholesterol, and the hypervariable region flanking the human insulin gene was studied in Saudi Arabian non-diabetic subjects (n = 68) and in patients with Type 2 diabetes (n = 35). A locus of insulin-gene-linked DNA polymorphism with three average size classes of alleles was found: a small class 1, a rare medium size class 2, and a large class 3 allele. In the total group of subjects (n = 103), those with the class 3 allele had a lower plasma HDL cholesterol concentration than those without the class 3 allele (0.93 +/- 0.26 vs 1.12 +/- 0.30 mmol l-1, 2p less than 0.003). No difference in genotype and allelic frequency was found between patients with and without coronary artery disease in the combined group of subjects, with and without diabetes. Similarly the genotype distribution was not different between non-diabetic subjects and patients with Type 2 diabetes in the combined group of subjects, both with and without coronary artery disease. In conclusion, the study did not confirm a previous study showing an association between the class 3 allele and atherosclerosis in a Caucasian population. However, the class 3 allele was associated with a low plasma HDL cholesterol concentration.

Alleles↗
PubMed1989

Development and evaluation of immunoassay for detection of antibodies to the feline T-lymphotropic lentivirus (feline immunodeficiency virus).

The feline T-cell lymphotropic lentivirus (feline immunodeficiency virus) is a recently described feline-specific retrovirus that can produce chronic immunodeficiency-like disorders in cats. A microdilution plate format enzyme-linked immunosorbent assay has been developed to detect the presence of antibody to the virus in feline serum or plasma. Temporal studies performed with experimentally infected animals show that seroconversion can be demonstrated 3 to 4 weeks after exposure to the virus. Results of a serosurvey (n = 1,556 samples) indicate that infection is fairly common in both clinic (5.2%) and sick cat (15.2%) populations. Western blot (immunoblot) and sodium dodecyl sulfate radioimmunoprecipitation assays were developed to confirm microdilution plate test results and to identify peptides specific for the feline immunodeficiency virus. All microdilution plate test positive results and selected negative results were confirmed by one or both of these procedures. These data demonstrate that this microassay plate enzyme-linked immunosorbent assay is a very sensitive and specific test for detection of antibody to the feline immunodeficiency virus.

Animals↗
PubMed1989

Percutaneous transluminal balloon dilatation of the mitral valve in pregnancy.

Pregnancy can cause life threatening complications in women with mitral stenosis, and there is a substantial risk of fetal death if valvotomy under cardiopulmonary bypass is required. A patient is described in whom pulmonary oedema developed after delivery of her first child by caesarean section 13 months previously. Subsequent cardiac catheterisation showed severe mitral stenosis (valve area 0.96 cm2, valve gradient 12 mm Hg, pulmonary artery pressure 30/16 mm Hg). Before valvotomy could be performed the patient again became pregnant and presented in pulmonary oedema at twenty two weeks' gestation. Medical treatment was unsuccessful and she underwent percutaneous transluminal balloon dilatation of the mitral valve. This increased the valve area to 1.78 cm2 and reduced the transmitral gradient to 6 mm Hg. The procedure was uncomplicated, and she remained symptom free on no medication. She delivered vaginally at 37 weeks' gestation. Percutaneous transluminal balloon dilatation of the mitral valve is a safe and effective alternative to mitral valvotomy in pregnancy.

Adult↗
PubMed1989

Arginine vasopressin is a much more potent stimulus to ACTH release from ovine anterior pituitary cells than ovine corticotropin-releasing factor. 1. In vitro studies.

Cultured rat and ovine anterior pituitary cells were treated with a range of doses (0.01-1,000 nM) of arginine vasopressin (AVP) and ovine corticotropin-releasing factor (CRF), alone or in combination, and medium and cell content of immunoreactive (ir-)ACTH determined. In rat cells, a dose-response curve to CRF was obtained, with a threshold dose of 0.1 nM; AVP was much less effective alone, but augmented CRF responses when administered with CRF. In ovine pituitary cells AVP markedly stimulated ACTH release in a dose-dependent fashion, and with a threshold of 0.1 nM; in contrast, CRF increased ACTH release over basal only at doses greater than 100 nM. In combination, subthreshold doses of AVP potentiated rat pituitary cell responses to CRF; addition of 1 nM of AVP to varying doses of CRF was more effective in terms of ACTH release than addition of 1 nM of CRF to increasing doses of AVP. In contrast, in ovine cells the addition of 1 nM CRF to increasing doses of AVP elicited a larger ACTH response than the addition of 1 nM AVP to increasing doses of CRF. Dexamethasone pretreatment (5 nM) for 48 h significantly decreased CRF potentiation of AVP-stimulated ACTH release in ovine cells. These studies confirm that CRF is a more potent stimulus of ACTH release than AVP in the rat, and establish that in contrast AVP is a much more potent stimulus of ACTH secretion than CRF in isolated ovine pituitary cells.

Adrenocorticotropic Hormone↗
PubMed1989

Positron emission tomography of the cerebellum in autism.

On the basis of neurological evidence that autistic patients have fewer Purkinje and granule cells in the cerebellum as well as vermal cerebellar hypoplasia, the authors tested the hypothesis that autistic patients have cerebellar hypofunctioning. They used positron emission tomography of the cerebellum with 18F-labeled 2-deoxyglucose to study seven autistic patients and eight age-matched control subjects. The results showed no significant difference in mean cerebellar glucose metabolism between the two groups, but all mean glucose rates of the autistic patients were either equal to or greater than those of the control subjects. The implications of these findings are discussed.

Adult↗
PubMed1989

A phase I study of intraarterial iododeoxyuridine in patients with colorectal liver metastases.

Regional delivery of iododeoxyuridine (IdUrd) to patients with colorectal liver metastases was examined in a phase I study. The maximum-tolerated intraarterial (IA) dose (MTD) was 1,333 mg/m2/d administered continuously for 14 days. The dose-limiting toxicity was thrombocytopenia. Thrombocytopenia and leukopenia were correlated with the amount of IdUrd incorporated into DNA of peripheral granulocytes. In contrast to our experience with 5-fluorodeoxyuridine, there was no evidence of hepatobiliary toxicity. In 11 patients who received IA IdUrd alone, seven had a greater than or equal to 50% decrease in carcinoembryonic antigen (CEA) levels, with five having tumor volume reductions of 65%, 48%, 46%, 44%, and 27%. Thus, IA IdUrd alone has antitumor efficacy. Patients subsequently received IdUrd in combination with external beam radiation to a total dose of 2,400 cGy without acute local toxicity. In addition to these favorable clinical findings, we have previously shown that IdUrd is selectively incorporated into tumor DNA compared with normal liver in these patients. Further phase II evaluations of this approach are warranted.

Antineoplastic Agents↗
PubMed1989

Vascular type I aldosterone binding sites are physiological mineralocorticoid receptors.

In vitro, Type I receptors have high and equivalent affinity for aldosterone, corticosterone and cortisol: in vivo, physiological mineralocorticoid target tissues (kidney, colon, parotid) are highly aldosterone-selective, in contrast with hippocampus and heart. In the present study we show that the mesenteric vascular arcade is similarly highly aldosterone-selective in vivo, and in vitro shows considerable levels of 11 beta OH steroid dehydrogenase activity, previously postulated as the mechanism whereby glucocorticoids are excluded from physiological mineralocorticoid receptors.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1989

Thermally induced formation of polychlorinated dibenzofurans from Aroclor 1254-contaminated mineral oil.

Numerous laboratory simulations and real-world events have demonstrated the thermal conversion of neat or high concentration of PCBs into the much more toxic PCDFs. Since millions of mineral oil transformers currently in service contain PCB concentrations in the 50 to 5000 ppm range, the thermal behavior of dilute PCB solutions is of practical and regulatory significance. In this work, neat Aroclor 1254 and 5000 ppm Aroclor 1254 in mineral oil were subjected to pyrolysis and combustion under a range of experimental conditions to define parameters resulting in maximal PCDF yields. The dependence of PCDF yield on Aroclor 1254 concentrations was then investigated in the 5000 to 50 ppm range. Combustion experiments demonstrated that PCDF yields expressed as micrograms PCDF/gram PCB were independent of concentration range, confirming that the process is kinetically first order in PCB. Much lower yields of PCDF were observed in the open tube pyrolysis experiments, as compared to combustion experiments and to earlier and concurrent sealed tube experiments. Slightly improved yields were observed in the pyrolysis experiments at lower concentrations, suggesting the existence of a PCB or PCDF destruction process of higher than first order kinetics. In all cases, yields expressed as micrograms PCDF/gram mixture were sharply and monotonically lower as concentrations decreased between neat or 5000 ppm Aroclor 1254 and 50 ppm Aroclor 1254.

Aroclors↗