Canine serum keratan sulfate and hyaluronate concentrations. Relationship to age and osteoarthritis

Elevated serum levels of keratan sulfate (KS) and hyaluronate (HA) in patients with osteoarthritis (OA) have been reported. We measured KS and HA in dogs to determine if there was an elevation of these serum glycosaminoglycans in a canine model of OA. A single intraarticular injection of 1 mg of chymopapain into a shoulder joint increased serum KS by tenfold, and HA by less than twofold, in 24 hours. Serum KS and HA levels were 3-5-fold higher in dogs younger than 2 months of age than in older dogs. Serum KS and HA concentrations and synovial fluid KS concentrations were unrelated to spontaneous cartilage degeneration in 1-year-old dogs. Higher KS levels in synovial fluid correlated with higher KS levels in serum (r = 0.54, P less than 0.025). The mean KS concentration in sera of older dogs (greater than 3 years old) with OA was 37% higher than that in disease-free controls, but the difference between the groups was not statistically significant. Thus, elevated levels of serum KS and HA do not appear to have clinical significance in this model of OA.     

Enhanced progesterone and testosterone secretion and depressed estradiol secretion in vitro from small white follicle cells of incubating turkey hens

This study was conducted to determine if lower steroid secretion by the small white follicles in incubating turkey hens contributes to lower circulating steroid concentrations during this time. Turkey hens were grouped as either laying or incubating. Serum samples and the ovarian small white follicles (SWF; 2-7 mm diameter) were collected from each hen. The SWF were pooled for each group and their cells were dispersed by trypsin digestion. Serum-luteinizing hormone (LH), progesterone (P), testosterone (T), and estradiol (E) concentrations were lower and serum prolactin concentration was higher during incubation than during egg laying. SWF cells from incubating hens secreted more P and T and less E in response to ovine luteinizing hormone (oLH) than did similar cell suspensions from laying hens. The incubating hens' SWF cells' capacity to secrete E but not their capacity to secrete P or T in vitro is consistent with the observed circulating levels. It is hypothesized that lower levels of circulating LH and/or higher levels of prolactin found in incubating hens may have a depressing effect on aromatase activity and/or an up-regulating effect on LH-induced P and T secretion by the SWF cells.     

Pulmonary edema in the renal failure patient

A patient with chronic renal failure presenting to the emergency department with acute pulmonary edema has a true life-threatening emergency. Whereas conventional treatment modalities may prove useful, more unusual therapeutic measures may be necessary. A case is presented followed by useful recommendations for the emergency physician faced with such a patient.     

Ingestion of immune bloodmeals and infection of Aedes fowleri, Aedes mcintoshi, and Culex pipiens with Rift Valley fever virus

Rift Valley fever (RVF) virus infection, dissemination, and transmission rates were determined for Aedes fowleri, Aedes mcintoshi and Culex pipiens 7 or 10 days after sequentially feeding to repletion on RVF virus immune hamsters and RVF viremic hamsters, or after feeding on a mixture of RVF virus immune sheep serum and RVF viremic hamster blood through a pledget. No significant differences in infection or dissemination rates were detected among Ae. fowleri and Cx. pipiens feeding to repletion on immune hamsters before or after feeding to repletion on a viremic hamster. Similarly, no significant differences in infection, dissemination, or transmission rates were observed among Ae. fowleri and Cx. pipiens feeding to repletion on immune hamsters or nonimmune (control) hamsters 0 or 24 hr after inoculation with RVF virus. Infection rates were significantly higher for Ae. fowleri (56/66, 85%) and Cx. pipiens (123/148, 83%) fed only on viremic hamsters than for those interrupted to complete feeding on an immune hamster (Ae. fowleri [24/49, 59%], Cx. pipiens [66/131, 50%]) or a nonimmune hamster (Ae. fowleri [32/51, 63%], Cx. pipiens [69/127, 54%]). However, no significant differences were detected in infection, dissemination, or transmission rates among Ae. fowleri, Ae. mcintoshi or Cx. pipiens fed on a viremic hamster and interrupted to complete feeding on an immune vs. a nonimmune hamster. Results from interrupted feeding experiments were significantly different from pledget feeding experiments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chronic thromboembolic occlusion in the adult can mimic pulmonary artery agenesis

In the first 100 patients operated on for C T-E PH, three were referred with the diagnosis of UPAA having been made elsewhere. We found that many features of these two conditions are so similar that differential diagnosis is very difficult. Shared features may include findings on chest x-ray film, pulmonary angiography, CT scan and MRI studies. Since the two conditions vary substantially with respect to the methods of potential surgical correction, recognition of this possible differential diagnostic dilemma is important.     

pH-dependent effects of lidocaine on defibrillation energy requirements in dogs

Lidocaine increases the energy required for ventricular defibrillation in dogs. Because sodium channel-blocking agents that are weak bases have pH-dependent electrophysiologic effects, we investigated the pH dependence of lidocaine (pKa, 7.9) on internal defibrillation energy requirements in 28 dogs with atrial spring and left ventricular patch electrodes. Results of defibrillation testing were used to derive 50% and 90% successful energy requirements (ED50 and ED90) using logistic regression and were compared with analysis of variance. Acidosis produced by hydrochloric acid infusion decreased the arterial pH from 7.40 +/- 0.05 (SD) to 7.18 +/- 0.03 (n = 8, p less than 0.01), but no significant change in ED90 was observed (14 +/- 4 to 16 +/- 6 J). Lidocaine infusion to therapeutic levels (4.2 +/- .07 micrograms/ml) at normal pH (7.42 +/- 0.02) increased ED90 from 13 +/- 3 to 17 +/- 3 J (n = 6, p less than 0.05), and subsequent acidosis (pH 7.19 +/- 0.02, p less than 0.01) exacerbated this effect of lidocaine on ED90 (22 +/- 5 J, p less than 0.05). Alkalosis produced by respirator hyperventilation increased the arterial pH from 7.41 +/- 0.03 to 7.60 +/- 0.03 (n = 8, p less than 0.01), with a fall in ED90 from 13 +/- 4 to 8 +/- 3 J (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence of lowest brain penetration of an antiemetic drug, metopimazine, compared to domperidone, metoclopramide and chlorpromazine, using an in vitro model of the blood-brain barrier.

PURPOSE: The objective of the current study was to determine the ability of some antiemetic compounds to cross the blood-brain barrier (BBB) and thereby to determine possible side effects of compounds for the central nervous system (CNS). METHODS: We compared the brain penetration of some antiemetic compounds using an in vitro BBB model consisting in brain capillary endothelial cells co-cultured with primary rat glial cells. RESULTS: This study clearly demonstrated that the metopimazine metabolite, metopimazine acid, has a very low brain penetration, lower than metopimazine and even less than the other antiemetic compounds tested in this study. CONCLUSIONS: The poor brain penetration of metopimazine acid, metopimazine biodisponible form, seems very likely related to the clinically observed difference in therapeutic and safety profile.