STUDIES OF THE DISTRIBUTION OF POLIOMYELITIS VIRUS : V. THE VIRUS IN FAMILIAL ASSOCIATES OF CASES

The occurrence and duration of the carrier state in familial associates of recognized cases of poliomyelitis was studied by the examination for virus of stool specimens collected from the members of four families at regular intervals for a period of over 2 months. The results indicate that: (1) virus may persist in their stools continuously for 4 to 5 weeks; (2) virus may be encountered intermittently in the stools; (3) in some instances virus may be present for brief periods only; (4) children are more likely to maintain virus than are adults in the same family; (5) infection of a family takes place rapidly, suggesting again simultaneous infection from a common source.     

Tumor vascular signals in renal masses: detection with Doppler US

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.     

Intracellular calcium changes in rat aortic smooth muscle cells in response to fluid flow

Vascular smooth muscle cells (VSM) are normally exposed to transmural fluid flow shear stresses, and after vascular injury, blood flow shear stresses are imposed upon them. Since Ca²⁺ is a ubiquitous intracellular signaling molecule, we examined the effects of fluid flow on intracellular Ca²⁺ concentration in rat aortic smooth muscle cells to assess VSM responsiveness to shear stress. Cells loaded with fura 2 were exposed to steady flow shear stress levels of 0.5–10.0 dyn/cm² in a parallel-plate flow chamber. The percentage of cells displaying a rise in cytosolic Ca²⁺ ion concentration ([Ca²⁺]_i) increased in response to increasing flow, but there was no effect of flow on the ([Ca²⁺]_i) amplitude of responding cells. Addition of Gd³⁺ (10 M) or thapsigargin (50 nM) significantly reduced the percentage of cells responding and the response amplitude, suggesting that influx of Ca²⁺ through ion channels and release from intracellular stores contribute to the rise in ([Ca²⁺]_i) in response to flow. The addition of nifedipine (1 or 10 M) or ryanodine (10 M) also significantly reduced the response amplitude, further defining the role of ion channels and intracellular stores in the Ca²⁺ response. © 2002 Biomedical Engineering Society. PAC2002: 8716Uv, 8719Uv, 8716Dg, 8719Ff     

CHANGING TRENDS OF LEPROSY IN ARMED FORCES

A total of 651 cases of leprosy were hospitalised from Jan 1987 to Dec 1992. Each patient underwent haemogram, total and differential white cell count, urinalysis, liver function tests, skin slit smear for AFB and skin biopsy. Nerve conduction studies, electomyographic studies and nerve/nerve sheath biopsies were undertaken as and when indicated. These patients were managed with multidrug therapy. Paucibacillary (PB) leprosy accounted for 476 (73.1%) cases which comprised of indeterminate leprosy 90 (13.8%), tuberculoid leprosy 14 (2.2%), borderline tuberculoid leprosy 310 (47.6%) and neuritic leprosy 62 (9.5%). The remaining 175 patients (26.9%) were multibacillary (MB) which included borderline leprosy 9 (1.4%), borderline lepromatous leprosy 129 (19.8%) and lepromatous leprosy 37 (5.7%) patients. There were total 153 patients in 1987. This number declined to 44 in 1992. PB declined from 113 in 1987 to 39 in 1992 and MB cases from 40 to 5.KEY WORDS: Leprosy     

Haemoptysis in healthy children due to unsuspected foreign body

Abstract: Haemoptysis in otherwise healthy children is an uncommon event. Two cases of massive haemoptysis, subsequently requiring lobectomy, are discussed. In each case, foreign vegetable matter was identified despite previously normal bronchoscopy and minimal changes on chest radiograph.     

Zinc replenishment reduces esophageal cell proliferation and N- nitrosomethylbenzylamine (NMBA)-induced esophageal tumor incidence in zinc-deficient rats

Previous work has shown that sustained increased and decreased cell proliferation, induced by dietary zinc deficiency and caloric restriction respectively, influence the course of N- nitrosomethylbenzylamine (NMBA)-induced esophageal carcinogenesis in rats. The present study considered whether the increased cell proliferation and esophageal tumor incidence induced by zinc deficiency are reversed upon zinc replenishment. Weanling rats were maintained initially on a deficient diet containing 4 p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated. After the second NMBA dose, the rats were divided into three dietary groups. One group was continued on the deficient diet, while the other two groups were switched to diets containing either 75 or 200 p.p.m. zinc, with half of the members in each group fed ad libitum and half pair-fed with deficient rats. NMBA-untreated controls were similarly replenished. At various time points, esophageal cell proliferation was assessed in five animals from each group by immunohistochemical detection of cells in S phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the first dose, esophageal tumor incidence was greatly reduced, from 100% in the deficient group to 26 and 14% respectively in the replenished groups fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats, to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following zinc replenishment, esophageal cell proliferation, as measured by labeling index (LI), the number of labeled cells and the total number of cells, was markedly decreased in NMBA-untreated and -treated esophagi as compared with those in corresponding deficient esophagi. Thus, the esophageal cell proliferation induced by zinc deficiency is reversed by zinc replenishment and replenished animals have a markedly lower incidence of esophageal tumors.