Schoolboy Rugby injuries, 1969-1986

For 18 years (1969-1986) a casualty station has been operating during all Saturday interschool Rugby matches at a private school. Since its inception, both the diagnosis and the early management have been documented for every injury that presented to this station. Over this period, 1444 boys have been seen, of whom 116 sustained injuries that were classified as being severe; of these, only two injuries--a skull fracture and a fracture--dislocation of the cervical spine--were regarded as clinically serious. Over all, the injury rate was 176/10 000 player-hours, or 1.56/100 player-games; the rate of severe injury was 14/10 000 player-hours, or 0.12/100 player-games. Injury rates were highest in older boys and in those who were in the most advanced grades of play. Fullbacks experienced the most injuries; otherwise, little variation occurred in injury rates by player position. No consistent trend in injury rates was observed over the period of the study.     

Outcome of surgery for failed endoscopic extraction of common bile duct stones in elderly patients.

Endoscopic sphincterotomy (ES) is the treatment of choice for common bile duct stones in elderly patients. For those in whom endoscopic clearance of the common bile duct fails the treatment options include stenting, dissolution therapy and lithotripsy. Surgery is often avoided because of the reported high morbidity and mortality in elderly patients. We have reviewed the outcome of patients referred for surgery after failed endoscopic clearance of common bile duct stones. Over a 3-year period, 100 patients with common bile duct stones were referred specifically for endoscopic clearance of the common bile duct (median age 69 years, range 19-97 years). In seven patients duct clearance was possible without ES and in five patients ES was considered inappropriate. ES was attempted in 88 patients and was successful in 75 (85%). Of the 13 patients failing ES or stone removal, surgery was performed in nine and four were stented. Of patients having successful ES (n = 75), ten were referred for surgery because of incomplete duct clearance. Surgery was performed to obtain duct clearance in 19 patients (eight male, 11 female, median age 77 years, range 47-90 years). Of the 19, eight had previously undergone a cholecystectomy (42%) and 17 of the 19 had biliary tract drainage preoperatively (90%). The procedures performed consisted of choledocholithotomy in all plus cholecystectomy (11), choledochoduodenostomy (7) and choledochojejunostomy (7). There were no deaths and only one major complication. The median total inpatient stay was 26 days (range 14-75 days) and the median postoperative stay was 12 days (range 7-50 days). We would conclude that open surgery can be performed safely and effectively in elderly patients with retained bile duct stones.     

-2-Hydroxyglutaric acid inhibits mitochondrial creatine kinase activity from cerebellum of developing rats

L-2-Hydroxyglutaric acid (LGA) is the biochemical hallmark of patients affected by the neurometabolic disorder known as L-2-hydroxyglutaric aciduria (LHGA). Although this disorder is predominantly characterized by severe neurological findings and pronounced cerebellum atrophy, the neurotoxic mechanisms of brain injury are virtually unknown. In the present study, we investigated the effect of LGA, at 0.25-5mM concentrations, on total creatine kinase (tCK) activity from cerebellum, cerebral cortex, cardiac muscle and skeletal muscle homogenates of 30-day-old Wistar rats. CK activity was measured also in the cytosolic (Cy-CK) and mitochondrial (Mi-CK) fractions from cerebellum. We verified that tCK activity was significantly inhibited by LGA in the cerebellum, but not in cerebral cortex, cardiac muscle and skeletal muscle. Furthermore, CK activity from the mitochondrial fraction was inhibited by LGA, whereas that from the cytosolic fraction of cerebellum was not affected by the acid. Kinetic studies revealed that the inhibitory effect of LGA on Mi-CK was non-competitive in relation to phosphocreatine. Finally, we verified that the inhibitory effect of LGA on tCK was fully prevented by pre-incubation of the homogenates with reduced glutathione (GSH), suggesting that this inhibition is possibly mediated by oxidation of essential thiol groups of the enzyme. Considering the importance of creatine kinase activity for energy homeostasis, our results suggest that the selective inhibition of this enzyme activity by increased levels of LGA could be possibly related to the cerebellar degeneration characteristically found in patients affected by L-2-hydroxyglutaric aciduria.     

Intrasplenic hepatocellular transplantation corrects hepatic encephalopathy in portacaval-shunted rats.

The aim of this work was to evaluate the effect of intrasplenic hepatocellular transplantation on hepatic encephalopathy in an experimental model of chronic liver failure induced by end-to-side portacaval shunt in the rat. Inbred male Wistar Furth rats were divided into three groups: rats subjected to portacaval shunt (n = 10), rats subjected to portacaval shunt and intrasplenic hepatocellular transplantation of 10(7) hepatocytes isolated from livers of syngeneic rats (n = 10) and sham-operated rats (n = 10). Behavior tests were performed in a blind fashion at 3 wk, at 2 mo and at 3 mo after surgery. Spontaneous activity and nose-poke exploration by individual rats were studied in automated open field boxes equipped with infrared cells. Each cell beam interruption was automatically recorded on a microcomputer and transformed into a score index (counts/hour). Plasma levels of amino acids, ammonia and total biliary acids were measured. Portacaval shunt rats showed reduced spontaneous activity and nose-poke exploration scores. Intrasplenic hepatocellular transplantation significantly increased spontaneous activity after 2 mo and improved nose-poke exploration after 3 wk. At 3 mo, spontaneous activity and nose-poke exploration in portacaval shunt/intrasplenic hepatocellular transplantation rats were not significantly different from those of sham rats. Increases in plasma ammonia levels after portacaval shunt were not corrected. Amino acid imbalance and bile acid concentration in plasma were partially corrected by intrasplenic hepatocellular transplantation. These data show that intrasplenic hepatocellular transplantation can correct the neurological symptoms of hepatic encephalopathy in an experimental model of chronic liver failure and suggest that intrasplenic hepatocellular transplantation might be of therapeutic interest in chronic liver failure.     

Alterations of the levels of glycoproteins Ib-IX and IIb-IIIa in platelets stored at 22°C

Platelets stored in CLX™ blood bags, under normal blood banking conditions, were studied for up to 7 days to determine if changes ocurred in the levels of membrane glycoproteins (GP) Ib-IX and IIb-IIIa. Radiolabeled monoclonal antibodies (MAB) were used to estimate the number of glycoprotein molecules on the surface membrane of intact platelets. GP IX and GP IIb-IIIa levels remained essentially unaltered during storage. In contrast, the content of GP Ib at day 7 decreased by 45% of the total when fresh. The aggregation response to ristocetin, which requires GP Ib, was also diminished after 7 days. Addition of protease inhibitors, leupeptin and/or aprotinin did not appear to influence the degradation of this glycoprotein. We conclude that storage at 22°C has deleterious effects on the GP Ib content of platelets.     

Cardiac ultrastructural and electrophysiological abnormalities in postweanling copper-restricted and copper-repleted rats in the absence of hypertrophy.

Cardiac ultrastructural and functional characteristics were determined in copper-depleted and copper-repleted rats. Male weanling rats were randomized into five groups that were fed either copper-adequate or copper-deficient diets. After 5 wk, one group fed each diet was studied to obtain baseline values. At this time, one copper-adequate postweanling group continued to receive the adequate diet as control, one deficient postweanling group was fed the adequate diet to evaluate the effect of copper repletion and one postweanling adequate group was fed the deficient diet to evaluate copper depletion in relatively older rats. These dietary treatments were continued for six additional weeks. Copper-depleted rats of both ages exhibited significant cardiac ultrastructural pathology and electrocardiogram abnormalities and the postweanling copper-depleted rats exhibited these abnormalities in the absence of hypertrophy and anemia. Increased mitochondrial volume density, disarranged cristae, and nonaligned myofibrils with disturbances at Z-bands were displayed. Additionally, all copper-depleted rats demonstrated fragmented basal laminae at capillary-myocyte interface. Increased QRS amplitude and notching and greater QT intervals were displayed. Copper-repleted rats exhibited some, but not total, reversal of these abnormalities. These results suggest that capillary-myocyte interface changes may play an important role in the developing pathology of copper depletion.     

The effects of prior exposure to silicone on capsule formation, histology, and pressure

Investigations into the effects of prior silicone exposure on subsequent capsule formation around silicone implants assume particular relevance in light of the exponential increase in the medical application of polymers such as silicone. The inert nature of silicone has been in question with regard to its effects on the immune system, specifically whether or not it may act as a hapten or antigen. The present study analyzes the effects of prior silicone exposure on subsequent capsule formation, histological consistency, and pressures when an animal is reexposed to a silicone implant. Twelve female Lewis rats (body weight 250 g) were randomly divided into two groups. Group 1 (n = 6) rats were subcutaneously injected with 2.5 ml of Freund's Complete Adjuvant, Group 2 (n = 6) rats were injected with an equal volume of adjuvant sonicated with silicone gel. At 4 weeks a gel-filled silicone implant was placed subcutaneously in each animal. Capsule pressures were obtained at 4 months and the capsules from 3 rats from Group 2 were excised and examined microscopically. Pressures were measured again at 8 months and all remaining capsules were excised and examined. No statistically significant differences were noted when comparing two profiles over time between silicone-exposed and nonexposed animals in regard to capsule thickness or capsule pressure. However, capsule pressures were significantly lower at 8 months than at 4 months in both groups (p less than 0.034). In this model, significant reductions in capsule pressure were noted in both groups over time, but prior exposure to silicone did not appear to alter capsule histology, thickness, or pressure.     

Didanosine (ddl) and stavudine (d4T): Absence of peripheral neurotoxicity in rabbits

Some 20 male New Zealand White rabbits (five/group) were given either didanosine (ddl) or stavudine (d4T) at 750 and 1500 mg/kg body weight/day by oral intubation for 24 wk. An additional group was given 300 mg/kg body weight/day zidovudine (AZT) as a negative control. After 13 weeks the high dose of ddl was lowered from 1500 to 1000 mg/kg body weight/day following the death of one rabbit and continued inappetence in the dose group. The rabbits were observed daily, plasma drug levels were monitored, and electrophysiological measurements of peripheral nerve conduction were performed during the study. Additionally, body weight and food intake were recorded, and clinicopathological parameters were evaluated. Sections of selected peripheral nerves, and dorsal and ventral spinal nerve roots were examined by light and transmission electron microscopy. Although peripheral neuropathy has been reported in rabbits with the nucleoside analogue zalcitabine (ddC), based on clinical observations, electrophysiological measurements, and light and electron microscopy, no evidence of peripheral neurotoxicity was observed in rabbits given either ddl or d4T.     

ASSESSMENT OF THE PREVALENCE INDEX ON SIGNS OF COMBINATION SYNDROME IN PATIENTS TREATED AT BAURU SCHOOL OF DENTISTRY,UNIVERSITY OF SAO PAULO

A group of destructive changes occurring in jaws in patients with maxillary complete dentures and mandibular removable partial dentures (bilaterally) has been described in the literature as the combination syndrome. However, this condition is not clinically observed in all patients. The aim of this study was to establish the prevalence index on signs of combination syndrome and to verify whether these changes also occurred in patients rehabilitated with a mandibular removable partial denture (unilaterally). Sample was composed of 44 patients, completely edentulous in the maxilla. Thirty-two patients had a Kennedy Class I removable partial denture and 12 a Kennedy Class II. Three major alterations were observed in 20.5% of the studied population. Nevertheless, these changes were present only in 25% of patients with Kennedy Class I removable partial denture. Based on the findings of this study, it can be concluded that patients with Kennedy Class II removable partial denture do not have similar signs that lead to the combination syndrome’s condition.