Influence of subacute starvation on cardiac response to isoproterenol in rats.

Several studies have reported that the heart is severely affected by chronic malnutrition. However, the influence of these alterations on cardiac function remains unclear. The aim of this study was to evaluate the effects of subacute starvation on the heart chronotropic response to a beta-adrenergic agonist (isoproterenol). Twelve rats were fed rat chow ad libitum or a 50%-restricted diet for 17 days. The rats were killed, the right atrium was isolated and incubated, and in vitro spontaneous cardiac contractions and frequency were registered. Cumulative doses of isoproterenol were added to the solution until maximal cardiac frequency was achieved. A deficit of 25% in the weight gain was observed in study rats compared with controls (92.6 +/- 10.2 vs. 113.8 +/- 19.2 g, p less than 0.05). Mean daily food intake was 4.8 +/- 0.1 and 9.8 +/- 0.5 g/day for semistarved and control rats, respectively. The in vitro cardiac frequency of the semistarved rats was similar to that of controls (290 +/- 15 and 305 +/- 23 beats/min, respectively, NS). However, when isoproterenol was added to the solution, maximal cardiac frequency of the semistarved rats (435 +/- 51 beats/min) was lower than that of control rats (508 +/- 34 beats/min, p less than 0.005). These findings suggest that subacute starvation may alter the cardiac response to beta-adrenergic agonists.     

Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques

BACKGROUND/PURPOSE: The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques. METHODS: Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.10%, 0.25% or 0.50% (w/w) of freeze-dried Aloe vera extract and applied to the volar forearm of 20 female subjects. Skin conditions in terms of the water content of the stratum corneum and of transepidermal water loss (TEWL) (Corneometer CM 825 and Tewameter TM 210) were analysed before and after a single and 1- and 2-week period of daily application. RESULTS: After a single application, only formulations supplemented with 0.25% and 0.50% (w/w) of Aloe vera extract increased the water content of the stratum corneum, while after the 2-week period application, all formulations containing the extract (0.10%, 0.25% and 0.50%) had the same effect, in both cases as compared with the vehicle. TEWL was not modified after a single and after 1- and 2-week period of application, when compared with the vehicle. CONCLUSION: Our results show that freeze-dried Aloe vera extract is a natural effective ingredient for improving skin hydration, possibly through a humectant mechanism. Consequently, it may be used in moisturizing cosmetic formulations and also as a complement in the treatment of dry skin.     

Immunopotentiation of bovine herpes virus subunit vaccination by interleukin-2.

Cattle were immunized with glycoprotein IV (gIV) from bovine herpes virus-1 (BHV-1). Groups of five animals were then given either 2, 3, 4, or 5 doses of interleukin-2 (IL-2) (0.5 microgram/kg) at 12-hr intervals. Animals that received no IL-2 exhibited specific immune responses that are typical for BHV-1 infection, i.e. enhanced specific cytotoxicity, lymphocyte proliferative responses to gIV, and increased gIV-specific (ELISA) and virus-neutralizing antibodies. Treatment of animals with five doses of IL-2 significantly augmented all of these responses except serum neutralization (P less than 0.05). Furthermore, the dose of IL-2 that was selected did not induce any non-specific responses, i.e. hypergamma-globulinaemia, changes in blood chemistry, increased lymphokine-activated killer (LAK) cell activity, changes in mitogen responsiveness or alterations in the phenotypic profile of circulating lymphocytes. Nor were there any clinical changes associated with IL-2 therapy (e.g. depression, pyrexia, diarrhea). Animals that were treated with less than five doses of IL-2 also exhibited elevated immune responses, but they were not significantly different from untreated immunized controls. Interestingly, animals given five doses of IL-2 responded to minor contaminants present in the gIV preparation. This allows speculation that this dose regimen of IL-2 is not only a potent adjuvant for conventional vaccine immunizing doses, but will also allow the use of minute quantities of antigen for immunization.     

Serum concentration of calcium and calcitonin in hyperthyroidism caused by Graves' disease]

Serum calcium and calcitonin were determined in 13 patients (12 women and 1 man), ages ranging from 30 to 40 years, with clinical diagnosis of hyperthyroidism due to Graves' Disease, confirmed by serum determinations of T3 and T4, with the purpose of establishing the relationship that these two substances may have in this pathology. The results obtained showed a decrease in seric calcium concentration in relation to a control group (10.02 +/-) 0.48 vs 11.49 +/- 0.28 mg/dl; p less than 0.005) and an increase in calcitonin concentration (193.6 +/- 8.62 vs 116.7 +/- 7.61 pg/ml; p less than 0.0001). We also found a significative negative association (r = -0.69; p less than 0.01) between these two compounds in the group of patients with hyperthyroidism, not being found in the control group.     

Comparative susceptibilities of ampicillin and chloramphenicol resistant Haemophilus influenzae to fifteen antibiotics

Eighty-three isolates of ampicillin and chloramphenicol resistant Haemophilus influenzae were tested for susceptibility to fifteen antibiotics by the agar dilution method. Fifty-four were from paediatric patients with H. influenzae disease and 29 from nasopharyngeal carriers (pre-school children). Twenty-five strains belonged to serotype b, one to serotype a, one to serotype c and the rest were non-typable. All strains produced beta-lactamase and inactivated chloramphenicol in a rapid bioassay, suggesting the production of chloramphenicol-acetyltransferase. The most active drugs were ceftriaxone, cefotaxime, latamoxef, aztreonam and desacetyl-cefotaxime (MIC90: 0.03, 0.06, 0.12, 0.25 and 0.25 mg/l, respectively). Cefuroxime, rifampicin and imipenem (MIC90 1 mg/l), and the combination of amoxycillin and clavulanic acid (MIC90 2:1 mg/l), also showed good activity. Cefaclor, erythromycin, tetracycline, trimethoprim, sulfamethoxazole and cotrimoxazole were the least active of the drugs studied. The excellent in-vitro activity of the new beta-lactam agents against H. influenzae resistant to ampicillin and chloramphenicol offers a therapeutic alternative in the treatment of serious infections caused by these micro-organisms.     

The effect of protein restriction on the severity and recovery from ischemic renal failure

The effects of chronic dietary protein restriction on ischemic renal failure were evaluated in rats subjected to 90 min of bilateral renal clamping. The rats were kept on either 20% casein (regular) diet or casein-free (protein-free) diet 10 days before and 21 days after renal injury. Rats on regular protein diet showed higher levels of BUN and serum creatinine and had a lower inulin clearance (microliter/min/100 g BW) than animals on protein-free diet (289 +/- 34 vs 582 +/- 103, p less than 0.05) 2 days after ischemia. However, the inulin clearance measured 21 days following ischemia was significantly higher in rats on regular diet (1468 +/- 181) than those maintained on protein-free diet after ischemia (560 +/- 167). When unilateral 90 min ischemia was performed in rats on regular diet, the postischemic kidneys showed an incomplete recovery of the inulin clearance (226 +/- 35) compared to the contralateral kidney (900 +/- 116), 21 days after ischemia; whereas in rats on a protein-free diet the inulin clearance averaged 106 +/- 17 in the postischemic kidney and 345 +/- 41 in the right kidney. When left renal ischemia and contralateral nephrectomy were performed, the inulin clearance was 1149 +/- 74 in rats on regular diet and 534 +/- 60 in rats on protein-free diet, 21 days following renal insult. These results suggest that protein restriction can play a protective role against renal ischemia in an initial phase, but it limits the late recovery from ischemia. The presence of a normal contralateral kidney inhibits the functional recovery of the postischemic kidney and a contralateral nephrectomy produces a compensatory functional hypertrophy of the postischemic kidney, even in rats on a protein-free diet.     

Loss of heterozygosity for distal markers on 22q in human gliomas.

Loss of constitutional heterozygosity as determined through the analysis of restriction-fragment-length polymorphism (RFLP) on tumoral and constitutional DNA has proven to be helpful to delimit the location of tumor-suppressor genes in the human genome. In malignant gliomas this approach indicates that chromosomes 9p, 10, 17p, and 22 may contain genes of this category involved in its origin and/or progression. Regarding chromosome 22, the data so far provided by molecular studies confirmed those previously reported by cytogenetic studies, suggesting the existence of a sub-group of malignant gliomas characterized by monosomy of this chromosome. However, the precise location of the putative glioma suppressor gene on chromosome 22 remains ambiguous. We have performed a combined cytogenetic and RFLP study on a series of 31 gliomas, looking for structural abnormalities of this chromosome. In 3 instances, terminal deletions of the long arm of chromosome 22 were observed by both methodologies, suggesting that the band q13 region distal to the D22S80 marker might be the critical domain non-randomly involved in tumor suppression of gliomas.