Induction of tissue-type plasminogen activator and 72-kDa type-IV collagenase by ionizing radiation in rat astrocytes

Radiation-induced damage in the central nervous system (CNS) is believed to be targeted to glial or endothelial cells or both, although the pathophysiology of the process is still poorly understood. In this study, we irradiated rat astrocytes with single doses of X-rays and then estimated the levels of tissue plasminogen activator (tPA) and collagenase in serum-free medium and cell extracts at different times. Fibrin zymography revealed increased levels of intracellular tPA activity at 12 hr after irradiation. Gelatin zymography showed continuously increasing levels of extracellular 72-kDa type-IV collagenase after irradiation. Quantitative enzymatic activities by densitometry showed a 3-to 4-fold elevation in the level of the intracellular tPA activity at 12 hr and a 5-to 6-fold increase in the level of the extracellular 72-kDa type-IV collagenase activity at 48 hr. An ELISA with specific antibodies for tPA and 72-kDa type-IV collagenase indicated a 5-fold increase in the level of tPA at 12 hr and a more-than-7-fold increase in the level of 72-kDa type-IV collagenase at 48 hr. This study adds considerable credibility to the proposed role of plasminogen activators and type-IV collagenase in the development of CNS damage after radiotherapy for brain tumors.     

Seroepidemiology of Helicobacter pylori infection in a population of Egyptian children

BACKGROUND: To describe the seroepidemiology of Helicobacter pylori infection in a population of Egyptian children under 3 years. METHODS: A cohort of children under 36 months, residing in Abu Homos, Egypt, were visited at home twice weekly. Information regarding the child's breastfeeding status was obtained, and periodic anthropometric and household hygiene surveys were performed. In June 1997, a serosurvey was conducted on 187 study participants over 6 months old. The serosurvey was repeated in October 1997. All sera were tested for IgG antibodies to H. pylori. RESULTS: The June prevalence of H. pylori infection was 10%, and the incidence from June to October was 15%. Between June and October, 8 (42%) of 19 children that were positive for H. pylori infection seroreverted to negative. All seroreversions occurred in children 6-17 months. Other than age, no sociodemographic or environmental factor was significantly associated with incident H. pylori infection. There was no significant differences in the weight-for-age, weight-for-height, and height-for-age z-scores between children with and without prevalent H. pylori infection. CONCLUSIONS: Infection with H. pylori is common in Egyptian children under 3 years old and is not associated with malnutrition. No predictors for H. pylori infection were found. Our preliminary evidence for transient H. pylori infections in young children needs to be confirmed in a prospective cohort study, and predictors for persistent infection should be sought, since only these may be relevant to the known sequellae of infection.     

Chronic suppression of testicular function by constant infusion of gonadotropin-releasing hormone agonist and testosterone supplementation in the bonnet monkey (Macaca radiata).

OBJECTIVE: To study the efficacy of long-term buserelin acetate infusion to desensitize pituitary and block testicular function in adult male monkeys (Macaca radiata). ANIMALS: Proven fertile male monkeys exhibiting normal testicular function. PROTOCOL: Each of the control (n = 5) and experimental monkeys (n = 10) received a fresh miniosmotic pump every 21 days, whereas pumps in controls delivered vehicle of experimentals released 50 micrograms buserelin acetate every 24 hours. On day 170 (renewed every 60 days) a silastic capsule containing crystalline testosterone (T) was implanted in the experimental monkeys. At the end of 3 years, treatment was stopped, and recovery of testicular function and fertility monitored. RESULTS: (1) Treatment resulted in marked reduction of nocturnal but not basal serum T; (2) the pituitary remained desensitized to buserelin acetate throughout the 3-year period; (3) animals were largely azoospermic with occasional oligospermia exhibited by two monkeys; and (4) withdrawal of treatment restored testicular function, with 70% of animals regaining fertility. CONCLUSION: Long-term infertility (but restorable) can be induced in male monkeys by constant infusion of buserelin acetate and T.     

Transient aplastic crisis in patients with sickle cell disease. B19 parvovirus studies during a 7-year period.

OBJECTIVE--To determine (1) the proportion of cases of transient aplastic crisis (TAC) in patients with sickle cell disease due to B19 parvovirus infection in several years, (2) longitudinally, the immune response to B19 parvovirus infection, and (3) whether patients with sickle cell disease experience recurrent or chronic B19 parvovirus infection. DESIGN--Prospective evaluation of patients with sickle cell disease and TAC to find evidence of B19 parvovirus infection and, if present, to document the pattern of serologic response with time. SETTING--Large urban teaching hospital. PATIENTS--Patients younger than 18 years with sickle cell disease who were admitted to the hospital with a diagnosis of TAC or who developed TAC while in the hospital for other reasons. Follow-up serologic studies of B19 parvovirus infection were done in eight patients. MEASUREMENTS/MAIN RESULTS--Serum was tested for B19 parvovirus DNA/viral particles and specific anti-B19 parvovirus IgM and IgG antibodies. B19 parvovirus DNA/viral particles were detected in 11 (21%) of 53 patients with TAC. Specific anti-B19 parvovirus IgM antibodies were detected in 34 (64%) of the 53 patients. Overall, 36 (68%) of 53 patients with TAC had evidence of acute B19 parvovirus infection as shown by the detection of B19 DNA parvovirus and/or specific anti-B19 parvovirus IgM antibodies in acute-phase serum. Follow-up serologic studies in eight patients with acute infection revealed disappearance of B19 parvovirus DNA/viral particles and anti-B19 parvovirus IgM antibodies and persistence of anti-B19 parvovirus IgG antibodies for up to 3 1/2 years after the diagnosis of acute B19 parvovirus infection. No patient had evidence of recurrent or chronic B19 parvovirus infection. CONCLUSIONS--Approximately 70% of cases of TAC in patients with sickle cell disease identified in a 7-year period were caused by acute B19 parvovirus infection. Once detected, anti-B19 parvovirus IgG antibodies remain detectable for several years. There was no evidence of chronic or recurrent B19 parvovirus infection in patients with sickle cell disease.     

Anticardiolipin antibodies in eclampsia.

Twenty patients with eclampsia were studied for the presence of anticardiolipin antibodies by the standard microflocculation test (quantitative) used in the VDRL. Four out of 20 patients (20%) were positive for anticardiolipin antibodies. Anticardiolipin antibodies which are antiphospholipid antibodies by decreasing the prostacyclin production may damage the vascular endothelium and cause thrombosis in the vessels. Hence, the presence of anticardiolipin antibody in eclampsia may have association with antiphospholipid antibody syndrome described by Harris et al. (Lancet ii: 1211, 1983) and its central nervous system sequelae.     

Nutritive value of traditional sweets consumed in the Arab Gulf countries

Proximate, mineral, fatty acid and cholesterol composition of eight traditional sweets commonly consumed in the Arab Gulf countries were determined. Four sweets were obtained from Bahrain, whereas the other sweets were obtained from Oman. Protein level ranged from 0.2 to 9.0%, while the fat content ranged from 7.9 to 18.0%. In general, the sweets were found to be high in energy content but poor in most minerals. Iron and zinc contents were low (less than 2 and less than 1 mg/100 g for iron and zinc, respectively). Cholesterol was high in four sweets (range from 10.6 to 20.4 mg/100 g), mainly because of the use of animal fat in preparation of these sweets. The fatty acids profiles showed that palmitic and oleic acids were predominant. One sweet (eggbaith) was found to be very high in linoleic (42%) and low in palmitic (9.6%) acids. The study showed that some traditional sweets are nutritious, while others should be consumed with moderation.     

Breastfeeding and weaning practices in relation to nutritional status of infants.

During the critical period of infancy, breastfeeding and weaning practices play an important role in determining the growth of an infant. The present study investigates the issue by observing 225 infants from Low Socio Economic (LSE) class (n = 150) and High Socio Economic (HSE) class (n = 75) for weight, height, and feeding practices. Almost all artificially fed (AF) infants in LSE class were malnourished while this was not so in the HSE class. However, the proportion of malnourished children in the LSE class for partially breastfed (BF + AF) group was comparable with exclusively breastfed (BF) group and was significantly lower (p < 0.01) than AF group indicating protective effect of partial breastfeeding against risks of contamination associated with weaning foods in such communities: The real bottleneck thus appears to be the lack of knowledge of handling and giving weaning foods in adequate quantities. Educating mothers appears to be the meaningful solution for improving the nutritional status of infants in poor communities.