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Biomedical subjects

N Hussain

Publications and source records attributed to N Hussain.

58 records · Page 4Linked to original sources
PubMed1983

The identification of specific serotonergic nuclei inhibited by cardiac vagal afferents during acute myocardial ischemia in the rat.

Cardio-cardiac autonomic reflexes mediated by the cardiac vagus during acute myocardial infarction play an important role in determining post-infarction hemodynamic function and the susceptibility of the infarcting heart to lethal arrythmias. In an earlier study we had demonstrated that serotonin-containing neurons in the brain participate in the mediation of these reflexes following left coronary artery ligation in the rat. In this study we identify brain serotonin nuclei involved. The accumulation of serotonin was measured in 19 brain nuclei from rats treated with pargyline, a monoamine oxidase inhibitor. The rats were subjected to either left coronary artery ligation or sham operation with or without bilateral cervical vagotomy or lidocaine applied topically only to the left ventricle. Serotonin accumulation was markedly reduced in the nucleus hypothalamicus posterior, nucleus raphe magnus and nuclei-raphe medianus-centralis superior in the rats subjected to coronary artery ligation as opposed to sham operation; no other brain regions were affected. The topical application of lidocaine to the left ventricle or vagotomy completely obviated the ligation-induced decrease in serotonin turnover. We conclude that there is an inhibition of serotonergic activity in the nucleus hypothalamicus posterior, nucleus raphe magnus and nuclei raphe medianus-centralis superior following left ventricular myocardial infarction in the rat. The afferent signal arises from receptors in the left ventricle and is conducted by the vagus.

Animals↗
PubMedDate not supplied

Morbidity and mortality of preterm twins and higher-order multiple births.

OBJECTIVE: To determine if preterm infants of higher-order multiple (HOM) gestations have a significantly worse outcome during hospital stay when compared with preterm twins. STUDY DESIGN: Retrospective cohort analysis. METHODS: Perinatal outcome variables including gestational age (GA), birthweight, prenatal steroid use, cesarean section delivery rate, Apgar scores, and growth retardation were analyzed for 106 preterm HOM births (triplets and quadruplets) versus 328 preterm twins admitted to a single tertiary level neonatal intensive care unit. A comparison of the mortality and major neonatal morbidities such as respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity was made for these two groups. In addition, the duration of respiratory support including surfactant therapy, nasal continuous positive airway pressure, and mechanical ventilation, as well as the length of hospitalization, was analyzed. RESULTS: There were no significant differences in major morbidities between the infants of HOM and twin births of similar GA. There was no statistically significant difference in mortality, but the data showed a trend for lesser mortality in HOM. There was a highly significant increase in antenatal steroid use as well as the use of cesarean section for delivery in the HOM when compared with twin gestations. The infants of HOM gestations were of significantly lower birthweight than the twins and had a longer hospitalization. CONCLUSION: Although premature infants of HOM had lower birthweight and needed a longer hospital stay, their mortality and morbidity at hospital discharge were not worse than that for preterm twins.

Adult↗
PubMedDate not supplied

Multiple field hyperthermia combined with radiotherapy in advanced carcinoma of the breast.

Extensive recurrences on the chest wall of advanced carcinoma of the breast in 20 patients were treated with multiple field patchwork hyperthermia combined with radiation therapy between 1987-1991. The objective of the study was to evaluate the feasibility, tumour response and complications of treating extensive lesions with multiple, overlapping fields of hyperthermia. All lesions were diffuse encompassing up to 2900 cm2 in area with or without multiple nodules < or = 3 cm deep. All lesions had failed previous therapy with all but three failing previous radiotherapy. Hyperthermia consisted of 282 hyperthermia applicator fields and 357 hyperthermia treatments with external 915 MHz microwaves using commercially available applicators. Hyperthermia applicator fields were defined by the surface 50% SAR distribution of a particular applicator, and hyperthermia fields were abutted to cover the entire tumour bearing area. Radiation therapy consisted of 81 fields to a mean dose of 40 +/- 1 Gy (SE), 88% of fields received between 30 and 50 Gy. The equivalent dose was 42 +/- 1 Gy, based on the linear-quadratic model and alpha/beta = 25 (Fowler 1989). Overlapping hyperthermia fields were separated by an interval of at least three days. Up to four heat sessions per week were required to cover the entire tumour in a rotating fashion. The hyperthermia treatment time was 60 min. Hyperthermia treatments were continued for the duration of radiation therapy. Each hyperthermia applicator field was heated at least once. Patients were exposed to a mean of 14 +/- 3 hyperthermia applicator fields (range of 3-46 fields) and a mean of 18 +/- 3 hyperthermia treatments (range of 6-61) delivered over a mean of 7.5 +/- 0.9 weeks (range of 3-17 weeks). Each field was heated an average of 1.3 times. The tumour complete response rate was 95% with a recurrence rate of 5%. Nevertheless, the mean survival of patients with a complete response was only 10.8 +/- 1.7 months (range of 2-28 months) because of the systemic tumour burden existing outside of the treated fields in these patients. Neither complete response, local control nor survival after thermoradiotherapy correlated with the disease free interval between initial mastectomy and recurrence. There was no evidence of increased thermal damage to skin nor evidence of tumour recurrence at junctions of hyperthermia field overlap. It is concluded that recurrent advanced carcinoma of the breast presenting as extensive, diffuse lesions on the chest wall can be treated as effectively with multiple field patchwork thermoradiotherapy as can nodular lesions treated with single hyperthermia fields.

Adult↗