A guinea-pig hereditary cataract contains a splice-site deletion in a crystallin gene

A congenital cataract present in guinea pigs provided a unique opportunity to study a hereditary lens disease at the molecular level. zeta-Crystallin, one of the most abundant guinea pig lens proteins, was found to be altered in the lens of cataractous animals. Several zeta-crystallin cDNA clones were isolated from a cataractous lens library and found to contain a 102-bp deletion towards the 3' end of the coding region. This deletion does not interfere with the reading frame but results in a protein 34 amino acids shorter. Sequence analysis of a normal genomic zeta-crystallin clone revealed that the missing 102-bp fragment corresponds to an entire exon (exon 7). PCR analysis of the genomic DNA isolated from cataractous animals showed that exon 7, though missing from the mRNA, is intact in the cataractous genome. Further sequence analysis of the zeta-crystallin gene disclosed a dinucleotide deletion of the universal AG at the acceptor splice-site of intron 6 of the mutant gene. The presence of this mutation results in the skipping of exon 7 during the mRNA processing which in turn results in the altered zeta-crystallin protein. This is the first time a genomic mutation in an enzyme/crystallin gene has been directly linked to a congenital cataract.

Noninvasive percutaneous induction of topical analgesia by a new type of drug carrier, and prolongation of local pain insensitivity by anesthetic liposomes

We studied the duration of action and permeability of common analgesics and local anesthetics applied dermally via new carriers--transfersomes--in rats and humans. The therapeutic potential of analgesic transfersomes was evaluated in Sprague-Dawley rats subjected to heat and pressure stimuli. Results were compared with those obtained from administration of lidocaine-containing standard liposomes. In rats, subcutaneous injections of 2% lidocaine solution and of liposomal or transfersomal suspension resulted in a strong initial analgesic effect that decayed within 6-7 min. Characteristic withdrawal time is approximately 30 s. Dermally applied analgesic transfersomes, by contrast, increased heat stimulus reaction to greater than 70 s, 130% longer than in controls that received a placebo or a standard aqueous lidocaine solution. In humans, we tested two groups of nine male and female volunteers, aged between 25 and 60 yr, for pain-suppressing activity assessed by the pinprick method. Each subject received a total of 0.5 mL of a transfersomal preparation containing 7% lidocaine or 4% tetracaine over a forearm area of 9 cm. We conclude that the effectiveness of dermally applied anesthetic transfersomes is similar to that of the corresponding subcutaneous injections of similar drug quantities and that optimally designed transfersomes offer a suitable and promising means for the noninvasive treatment of local pain with direct, topical drug application.

Alterations induced by fascioliasis and cirrhosis on the biliary excretion of cefmetazole in wistar rats

1. Alterations induced by fascioliasis and cirrhosis on the biliary excretion of cefmetazole have been studied in Wistar rats. 2. Both infestation with Fasciola hepatica and experimental cirrhosis originated a significant decrease in the biliary excretion and in bile flow increase induced by the drug. 3. Administration of the beta-lactam antibiotic induced a lower degree of uncoupling of biliary lipid secretion in the cirrhotic and fasciolotic animals, but the effect was evident in all experimental groups.

Nodular regenerative hyperplasia in the rat induced by a selenium-enriched diet: study of a model

Weaned male rats were fed a 4 ppm selenium diet. Compared after 2 mo with a control group fed a 0.4 ppm diet, the rats' body weights had not significantly decreased and liver function was normal, but portal pressure was 1.8 times higher (p less than 0.05). Liver weight was slightly increased (10.3%; p less than 0.05). All livers had an abnormal appearance. In the less severe cases the surface was only slightly irregular, but in the more severe cases, atrophic micronodular lobes and hypertrophic lobes, with mildly irregular surfaces, were present. On light microscopy, atrophic lobes displayed a peripheral nodular zone with micronodules separated by rows of atrophic hepatocytes without fibrosis, characteristic of nodular regenerative hyperplasia, and a central atrophic zone that was sometimes peliotic. Hypertrophic lobes and livers in the less severe cases had only minor and relatively localized evidence of nodular regenerative hyperplasia; occasional peliosis was seen. In all cases portal veins, hepatic veins and hepatic arteries were normal. By electron microscopy, in nonnodular zones with no obvious evidence of parenchymal atrophy, the endothelial wall showed signs of complete or incomplete capillarization with frequent enlargement of the Disse space. The selenium-enriched diet is a reproducible model of liver nodular regenerative hyperplasia. In this model, damage to the sinusoidal wall could represent the primum movens of microcirculatory disturbances.

Assessing the loneliness of workers with mental retardation

This study was designed to determine whether a reliable instrument could be developed to measure the loneliness experienced by workers with mental retardation. In addition, supervisors were asked to rate subjects on loneliness and four other behavioral subtypes in order to determine whether there was a relation between these ratings and the loneliness questionnaire. Three groups of subjects were assessed: persons with mild, moderate, and severe mental retardation. Results indicated that the Worker Loneliness Questionnaire was a reliable instrument for use with persons with mild and moderate mental retardation. In addition, the results showed that some individuals were lonely; however, this was not a pervasive feeling. The implications for measuring the self-perceptions of individuals with mental retardation were discussed.

Hepatic disposition of organic anions in rats infested with Fasciola hepatica

This study was undertaken to investigate the effects of subclinical fascioliasis at various stages of its development (3, 6, and 11 weeks after infestation with an oral dose of 20 metacercariae of Fasciola hepatica) on the hepatobiliary transport of organic anions in rats. Basal bile acid secretion was not significantly modified in infested rats as compared to the controls but there was a significantly increased bile flow in the 11-week group. In all infested rats, maximal biliary excretion and cumulative excretion of bromosulphthalein was significantly reduced, although there was a tendence to recovery in the 11-week infested group. Decreased biliary secretion was accompanied by increased plasma and liver concentrations of bromosulphthalein. Glutathione S-transferase activity was significantly reduced by Weeks 3 and 6 postinfestation. Liver glutathione concentration was significantly reduced in all infested rats. Maximal excretion of dibromosulphthalein, a compound not biotransformed in the liver, fell by Week 6 postinfestation and recovered a normal value thereafter. These results indicate that effects of experimentally induced fascioliasis on hepatic disposition of organic anions depend upon the stage of its development and that are a consequence of both metabolism and transport related factors.

Hepatic transport of bilirubin in rats with streptozotocin-induced diabetes

This study was undertaken to evaluate the effects of streptozotocin-induced diabetes on the hepatic transport of bilirubin in male Wistar rats. Rats were pretreated with streptozotocin (60 mg/kg i.p.) to induce uncontrolled diabetes. Six days later endogenous biliary excretion and plasma bilirubin concentration were significantly enhanced compared to control animals (+36% and +46%, respectively), while the blood levels of free hemoglobin remained unchanged. Following a bilirubin load, the maximal biliary excretion of the pigment (Tm) in diabetic animals was significantly enhanced compared to control animals (+49%). Liver and plasma bilirubin concentrations at the end of bilirubin administration were significantly reduced (-28% and -30%, respectively). Bilirubin UDP-glucuronosyltransferase activity and UDP-glucose concentration in liver were significantly enhanced (+31% and +81%, respectively), as was the biliary excretion of unconjugated bilirubin (+37%) and bilirubin mono- (+38%) and diconjugates (+53%). When streptozotocin-diabetic rats were treated with insulin, the parameters of bilirubin transport and metabolism were significantly reduced compared to diabetic animals receiving no hormone replacement. In summary, our data indicate that in short-term streptozotocin-diabetic rats there is increased bilirubin production as well as enhanced hepatic conjugation and subsequent biliary excretion of the pigment. These effects appear to be a direct consequence of diabetes.

[Conservative treatment of bladder and prostatic rhabdomyosarcoma in childhood: possibilities for non-radical surgery]

Treatment of rhabdomyosarcoma (RMS) of the bladder and prostate has always been difficult. Despite the significant advancements that have permitted cure, there is no agreement in the choice and order of the different therapeutic options. We reviewed the available literature evaluating the role of non-radical surgery and attempts at bladder preservation especially in children. Partial resection with sufficient margin of safety is only possible in 20% of the primary bladder tumors and the 3-year survival rate is 80%, similar to the overall survival rate for tumors localized to this site. The excellent results achieved in the case described herein underscores the possibilities of a conservative treatment modality in well-selected cases. The patient, who was submitted to partial cystectomy and received VAC polychemotherapy for a period of one year, is alive, tumor free and has preserved bladder function 50 months post-operatively.

Inducible perivascular cells contribute to the neochondrogenesis in grafted perichondrium

Autogeneic perichondrium was implanted above the cremaster muscle of the rat, and the new formation of two types of cartilage (types I and and II) was confirmed. Also, granulation tissue was observed before the type II cartilage formation. Under these conditions, the contribution to the neocartilage of graft bed derived cells, mainly of the venule pericytes, was studied. To follow the pericyte lineage, we used a marker--Monastral Blue B--the administration of which was based on the principle of vascular labeling. While the perichondrium was kept free, before its implantation, the preformed (preexisting) venules in the cremaster muscle were exclusively labeled with Monastral Blue B, which was incorporated into the cytoplasm of pericytes and endothelial cells. After perichondrium implantation, the following sequence in tracer distribution was demonstrated. During the earlier stages, labeling was restricted to the pericytes and endothelial cells of venules in the graft bed. Later the tracer was observed in some endothelial cells and pericytes of the growing vessels and in fibroblast-like cells of the granulation tissue. Finally, some type II neochondrocytes appeared labeled. Tracer was not found in type I neochondrocytes. The presence of label in type II neochondrocytes demonstrates that they arise from progenitor cells present in the graft bed, principally from small venule pericytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuing controversy in alloimmune thrombocytopenia: fetal hyperimmunoglobulinemia fails to prevent thrombocytopenia

Two patients with severe alloimmune thrombocytopenia were managed by weekly intrauterine platelet transfusions at 25 to 36 weeks. In one patient high-dose immunoglobulin was also administered weekly to the mother, and high maternal and fetal immunoglobulin levels were achieved. Fetal platelet counts were similar in both patients. The only variable that affected fetal platelet concentration was the posttransfusion platelet count from the previous transfusion.

The transcripts of zeta-crystallin, a lens protein related to the alcohol dehydrogenase family, are altered in a guinea-pig hereditary cataract

Zeta-Crystallin, a major component of the guinea-pig lens proteins, is distantly related to the enzymes of the zinc-containing alcohol dehydrogenase family (ADH). Analysis of the structural similarities between zeta-crystallin and ADH reveals that while characteristics important in maintaining the tertiary structure of the molecule appear conserved, the amino acids binding the catalytic zinc atom are absent in zeta-crystallin. Significantly, zeta-crystallin does not have ADH activity. Previous studies showed that the zeta-crystallin protein is modified in the lens of guinea-pigs affected with an autosomal dominant hereditary cataract. We have further investigated the molecular origin of the lens defect by examining the steady-state levels of zeta-crystallin transcripts in normal and mutant eyes. Our data indicate that no normal zeta-crystallin mRNA is present in the lens of the homozygous animals; instead, a cross-hybridizing lower molecular weight mRNA is detected at significantly reduced concentrations. Heterozygous lenses exhibit both mRNA species.

Effects of pimobendan and UD-CG-212 CL on calcium exchange and contraction in isolated rabbit aorta

The effects of pimobendan and its O-demethylmetabolite UD-CG-212 CL on contractile responses and transmembrane Ca fluxes were studied on rabbit isolated aortic rings. Both pimobendan and UD-CG-212 CL (10(-7) M-5 X 10(-4) M) concentration-dependently inhibited the contractile responses induced by KCl (80 mM) and noradrenaline (10(-6) M). This inhibitory effect was observed when these compounds were added either before or after the induced contractions, but was reduced in aortic rings after removal of endothelium. Pimobendan and UD-CG-212 CL shifted the concentration-response curve to noradrenaline downwards and to the right and inhibited the contractile responses elicited by addition of Ca (1-5 mM) to Ca-free high K solution. Pimobendan also inhibited the contractile responses induced by caffeine (20 mM) in aortic rings incubated in normal or in Ca-free medium. At 5 X 10(-4) M, pimobendan inhibited 45Ca influx in resting as well as in aortic rings stimulated by high K and noradrenaline and increased the rate of 45Ca efflux in nonstimulated aortae. It is concluded that pimobendan and its O-dimethylmetabolite UD-CG-212 CL exhibit vasodilator properties in the isolated rabbit aorta by their acting at multiple sites of action, thus decreasing the availability of Ca required for smooth muscle activation.

[Perspectives of liver transplantation in Chile]

After an initial experience with 4 patients who received orthotopic liver transplant (OLT) we analyze the perspectives of establishing liver transplantation programs in Chile. An estimated 100 adult and pediatric patients require OLT a year and no more than 3 centers are required to deal with this and acquire experience with the procedure. A national organization for organ procurement is essential, given the marked difficulties in obtaining cadaver organs at present. Each procedure has an estimated cost of $5 million with 2 more millions in the first year. Thus a program for 15 patients a year may cost $ 100 million, personnel expenses not included.

Calcaneonavicular coalition treated by resection and interposition of the extensor digitorum brevis muscle

Seventy-five feet in forty-eight patients that had calcaneonavicular coalition were evaluated at two to twenty-three years after resection of the coalition and interposition of the extensor digitorum brevis muscle. The result was excellent or good in fifty-eight feet (77 per cent). Three feet that were rated initially as having a fair result improved over time, and at the last follow-up the result in those feet was rated as good. Only five feet (7 per cent) had a poor result. The best results were in patients who had a cartilaginous coalition and who were less than sixteen years old at the time of operation.

[Effect of treatment with clindamycin, erythromycin, rifamycin or gentamicin on the ingestion capacity of peritoneal macrophages in mice]

The effect of treatment with clindamycin, erythromycin, rifamycin and gentamicin on the ingestion capacity of the mouse peritoneal macrophage was studied. Female six-eight week old OF1 mice were treated with minimum and maximum doses clinically used for the different antibiotics (15 and 40 mg/kg/day of clindamycin, 15 and 57.5 mg/kg/day of erythromycin, 10 and 30 mg/kg/day of rifamycin, 3 and 6 mg/kg/day of gentamicin). Two treatment periods of 72 hours and one week were assayed for each antibiotic-dose combination. Antibiotic was administered twice daily, every twelve hours. Twelve hours after the last dose was given, macrophages were obtained through peritoneal lavage and a kinetic study of Candida albicans blastospore ingestion was made. One week treatment with 15 mg/kg/day and 72 hours treatment with 57.5 mg/kg/day of erythromycin produced a significant ingestion enhancement whereas one week treatment with 57.5 mg/kg/day of erythromycin and all treatments with gentamicin gave rise to an ingestion depression. 72 hours treatment with 15 and 40 mg/kg/day and one week treatment with 15 mg/kg/day of clindamycin, 15 mg/kg/day of erythromycin and 10 and 30 mg/kg/day of rifamycin did not modify macrophage ingestion capacity. One week treatment with 40 mg/kg/day of clindamycin and 10 and 30 mg/kg/day of rifamycin gave rise to an acceleration of the ingestion process.

Social ecology of the workplace: contextual variables affecting social interactions of employees with and without mental retardation

The social interaction patterns of employees with and without mental retardation across several different competitive employment sites were observed directly; narrative recording procedures were used. The data were analyzed to determine whether there were differences between the two groups of employees and the people involved in the interactions and the time period of the interaction and whether the interaction involved a social or task-related topic. The results were discussed in relation to their implications for integrating workers with mental retardation into settings with nonhandicapped workers.

Cisplatin nephrotoxicity: symptomatic hypomagnesemia and renal failure

Cisplatin is an inorganic platinum compound used in the treatment of solid tumors. Clinical trials have proved its efficacy whilst recognising the nephrotoxicity of the drug. We report the case of a 14 1/2 year old female with an epidermoid carcinoma of the lung, who developed acute renal failure following two courses of Cisplatin. The predominant features were symptomatic hypomagnesaemia, hypocalcaemia and hypokalaemia which were corrected following the administration of intravenous magnesium. Renal failure persisted for several months and the patient died due to her primary disease. Electrolyte disturbances should be anticipated when high dose Cisplatin is used.