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Biomedical subjects

R Nair

Publications and source records attributed to R Nair.

At least 127 records · Page 7Linked to original sources

Alternative indications for pulsatile gonadotropin-releasing hormone therapy in infertile women.

Three groups of women with different types of ovulatory dysfunction who had failed to conceive on conventional therapy were treated with pulsatile gonadotropin-releasing hormone (GnRH). Group A consisted of nine patients with luteal phase defect; group B included four patients with apparently normal menstrual cycles but disordered folliculogenesis seen by serial ultrasound examinations; and group C consisted of eight patients who exhibited anovulation or irregular ovulation. GnRH was administered subcutaneously or intravenously in dosages varying from 5 micrograms to 20 micrograms, with pulse frequency of 2 to 3 hours in 53 cycles. Forty-one cycles were ovulatory. Four pregnancies resulted, one ending in miscarriage at 12 weeks' gestation. Our results indicate that GnRH may be used as an alternative to the prevalent therapeutic methods for ovulatory dysfunction. Only those women who had anovulation and abnormal basal levels of serum luteinizing hormone were resistant to GnRH therapy.

Adult↗

Placental site, parity, and date of quickening.

The influence of placental site and parity on the date of quickening was studied in 112 gravidas. With placental site on the anterior uterine wall, quickening occurred at a mean gestational age of 19 weeks in primigravidas, and 17 weeks, five days in multiparas. With placental site on the posterior uterine wall, quickening occurred at a mean gestational age of 18 weeks in primigravidas, and 16 weeks, one day in multiparas. It is concluded that placental site influences quickening independent of parity and that it is a major factor in determining the stage at which fetal movements are first felt.

Female↗

Endocrine function following complex partial seizures.

Previous studies have demonstrated hyperprolactinemia following generalized tonic-clonic seizures and after electroconvulsive therapy. We found transient hyperprolactinemia following complex partial seizures but little change in serum gonadotropins, thyroid-stimulating hormone, growth hormone, or cortisol. Serum prolactin was invariably normal interictally. Postictal elevation of serum prolactin may represent a biochemical marker of complex partial seizures, and it offers a potential pathogenic mechanism for the sexual dysfunction that often complicates temporal lobe epilepsy.

Adult↗

Effector cell-mediated immune response in mice immunised with Salmonella.

Effector responses of cell-mediated immunity were studied in mice immediately and 3 months after immunisation with different kinds of salmonella vaccine. Whereas immunisation with live Salmonella enteritidis generated delayed hypersensitivity and activated macrophages, immunisation with formalised vaccine generated neither. Although activated macrophages had declined considerably by 3 months after immunisation, the delayed-hypersensitivity response had persisted. It was possible to generate activated macrophages in these mice by stimulation with sonicate antigens of the immunising strain or Salmonella paratyphic C. Delayed-hypersensitivity responses were elicited in mice, immunised with live S. enteritidis, by sonicate antigens of the homologous strains, S. gallinarum or S. paratyphi C.

Animals↗

Transient and residual stresses and displacements in self-curing bone cement - Part II: thermoelastic analysis of the stem fixation system.

In this second part of a two-part report, an idealized model of the stem fixation system is analyzed to determine the adverse effects of the thermal stresses and displacements of bone cement during its curing process. The Shaffer-Levitsky stress-rate strain-rate law for chemically hardening material has been used. The results show that if the cement is surrounded by cancellous bone, as opposed to cortical bone, then transient tensile circumferential stresses in the cement and similar radial stresses at the stem/cement interface are generated. The former may cause flaws and voids within the still cement, while the latter may cause gaps at the interface.

Bone Cements↗

Prolactin-secreting adenoma as part of the multiple endocrine neoplasia--type I (MEN-I) syndrome.

Two patients presented with the galactorrhea-amenorrhea syndrome. One patient had previously had parathyroid hyperplasia and the other an insulinoma. Preoperative evaluation of each patient revealed hyperprolactinemia and radiological evidence of an abnormal sella turcica. Pituitary adenomas were identified and removed at surgery. Immunostaining techniques confirmed the presence of prolactin-containing cells in both tumors. We propose that prolactin-secreting tumors be considered as part of the MEN-I syndrome, and that patients presenting with the galactorrhea-amenorrhea syndrome be screened and followed sequentially for evidence of other endocrine neoplasia.

Adenoma↗

An analysis of the dosimetry for mantle field therapy using 4 MV X-rays and its routine application.

There are several different methods in vogue at present in determining patient midplane doses in the "mantle" treatment for Hodgkin's disease and malignant lymphomas. A method of determining midplane doses in individual cases using thermoluminescent dosimetry is presented. It shows excellent agreement with the midplane doses measured in an Alderson-Rando phantom treated as a hypothetical "mantle" patient.

Hodgkin Disease↗

A study of dose distribution patterns from cobalt-60 and Varian Clinac-4 beams.

Dose distribution patterns of 4 MV x-rays from a Varian Clinac 4 linear accelerator are compared with those from a 60Co teletherapy machine. Field flatteners of lead and depleted uranium were used. Dose distribution maps display the off-axis high dose or "horns" with lead filters and circular dose distribution patterns. The uranium field flattener clearly "clipped the horns" and eliminated circular dose distribution patterns with larger fields.

Cobalt Radioisotopes↗

Estimation of hepatic bilirubin UDP-glucuronyl transferase in patients with noncirrhotic portal fibrosis and liver disease: Significance and limitations.

Using a micromethod, hepatic bilirubin UDP-glucuronyl transferase has been assayed in percutaneous needle biopsy samples obtained from patients with infectious hepatitis, postnecrotic cirrhosis, Gilbert's disease, noncirrhotic portal fibrosis (NCPF), granuloma of the liver, and extrahepatic portal vein obstruction. The results were compared with those obtained from 10 control subjects. Patients with cirrhosis and infectious hepatitis revealed normal bilirubin transferase levels, whereas those with Gilbert's disease showed significantly low enzyme levels. Many patients with NCPF, some with extrahepatic portal vein obstruction, and patients with granulomatous involvement of the liver demonstrated significantly low levels. This low hepatitic-enzyme activity was not associated with hyperbilirubinemia. The mechanism of such low values in NCPF and other disorders is not known. It is postulated that low heaptic-enzyme activity in noncirrhotic portal fibrosis is due to sparse smooth endoplasmic reticulum. This study also emphasizes that serum bilirubin may remain normal with very low hepatic-enzyme activity. Although induction of the microsomal enzyme bilirubin transferase was observed following phenobarbitone administration in noncirrhotic portal fibrosis, this was not apparent in patients with cirrhosis, possibly due to maximal enzyme induction having been achieved by endogenous substrate.

Adult↗

Intensive chemotherapy in children with stage IV neuroblastoma.

A retrospective analysis of effectiveness of sequential chemotherapy with cyclophosphamide, doxorubicin, cisplatin and etoposide in children with stage IV neuroblastoma was undertaken. Study group included 17 children of mores than one year old with median age of 3 years (range 18 months to 7 years). Fourteen were males and three females. Sites of primary tumor were abdomen in 12 patients, pelvis in 3, paravertebral in 1 and unknown in 1. Metastatic sites included bone marrow (88%), bone (82%), orbit (29.4%) and lymph node (11.7%). One patient had brain parenchymal disease and another had cerebrospinal fluid positivity for malignant cells. Fifteen of the 17 patients had major response with chemotherapy (complete response in two and partial response in 13). Ten of the 15 patients completed four courses of chemotherapy and five patients progressed while on chemotherapy and died. Only two of the ten patients, who had four courses chemotherapy are alive after 2 years. Hence the 2-year survival in this series is 11.7%. There was no toxic death in this study.

Child↗