Perceived social support and community adaptation in schizophrenia

Prompted by the continuing transition to community care, mental health nurses are considering the role of social support in community adaptation. This article demonstrates the importance of distinguishing between kinds of social support and presents findings from the first round data of a longitudinal study of community adaptation in 156 people with schizophrenia conducted in Brisbane, Australia. All clients were interviewed using the relevant subscales of the Diagnostic Interview Schedule to confirm a primary diagnosis of schizophrenia. The study set out to investigate the relationship between community adaptation and social support. Community adaptation was measured with the Brief Psychiatric Rating Scale (BPRS), the Life Skills Profile (LSP) and measures of dissatisfaction with life and problems in daily living developed by the authors. Social support was measured with the Arizona Social Support Interview Schedule (ASSIS). The BPRS and ASSIS were incorporated into a client interview conducted by trained interviewers. The LSP was completed on each client by an informal carer (parent, relative or friend) or a professional carer (case manager or other health professional) nominated by the client. Hierarchical regression analysis was used to examine the relationship between community adaptation and four sets of social support variables. Given the order in which variables were entered in regression equations, a set of perceived social support variables was found to account for the largest unique variance of four measures of community adaptation in 96 people with schizophrenia for whom complete data are available from the first round of the three-wave longitudinal study. A set of the subjective experiences of the clients accounted for the largest unique variance in measures of symptomatology, life skills, dissatisfaction with life, and problems in daily living. Sets of community support, household support and functional variables accounted for less variance. Implications for mental health nursing practice are considered.

The effect of grain storage conditions on the viability of Fusarium and deoxynivalenol production in infested malting barley

A continuing outbreak of Fusarium head blight occurred on barley in the upper Midwest from 1993 to 1995. This resulted in barley with levels of the mycotoxin deoxynivalenol (DON) reaching levels of concern for maltsters and brewers. This study evaluated the effect of 7 months of storage under different conditions (ambient outdoor temperature from October to April), -20 degrees C, 4 degrees C, 24 degrees C with quiescent air, and 24 degrees C with forced air) on the viability of Fusarium and Alternaria infesting stored grain. Additionally, the ability of Fusarium to produce DON after storage and during malting was evaluated. Initial levels of infestation of barley by Fusarium and Alternaria were 85 and 75%, respectively. All storage condition reduced the viability of both molds slightly and significantly for Fusarium. Forced air ventilation at 24 degrees C was the type of storage most effective in reducing the viability of Fusarium, dropping the percentage of infected kernels to 66%. DON levels did not change after 7 months with respect to storage conditions. However, DON levels were lower in malt produced from barley stored at 24 degrees C with or without aeration. On-farm storage of infected barley at elevated temperatures may provide a means to reduce the level of DON in finished malts.

A cluster of serious Escherichia coli infections in a neonatal intensive-care unit

A cluster of serious Escherichia coli infections was identified among patients in a neonatal intensive-care unit. Infection control staff identified the outbreak because they realized that E coli rarely caused infections in this unit. Pulsed-field gel electrophoresis confirmed that one strain of E coli was transmitted among patients.

Acute iron intoxication: significant differences between sexes

Iron, one of the common medications in use among children and adults, is the leading cause of pediatric unintentional ingestion fatalities and is not an uncommon poisoning among adults. Accidental ingestion is common because iron-containing compounds are readily available, brightly colored, often sugar coated, and frequently considered harmless vitamins. There are no data on differences between sexes with regard to iron intoxication, and the management of iron overdose is the same for females and males. After oral administration by gavage of the LD50 of iron to Wistar rats, the pharmacokinetics of iron, baseline and peak serum iron levels, and mortality rates were compared between sexes. Prepubertal females died significantly more than males (p < 0.01), pubertal females died significantly earlier than males (p < 0.04), and the same was true among adult rats (p = 0.02). Baseline serum iron levels were not significantly different between prepubertal female and male rats, but female pubertal rats had significantly higher baseline iron levels than males (p = 0.006). After iron administration, females had significantly higher peak serum iron concentrations (p < 0.03). Mechanisms of iron absorption are still not completely known and, probably, there are differences in iron absorption between sexes, which may account for the differences in serum iron levels and mortality rates. While the therapeutic approach in cases of intoxication is individual, iron intoxication, as may be true for other poisonings also, treatments administered to females may need to be different from that given to males.

Heliox therapy for pneumothorax: new indication for an old remedy

STUDY OBJECTIVE

To evaluate a new method of treating pneumothorax: having the subject breathe a helium/oxygen mixture (heliox).

METHODS

We conducted a prospective, randomized, controlled study of nine white rabbits weighing 2.5 to 3.5 kg. Experimental pneumothorax was induced in all rabbits with the injection of 20 mL of air into the pleural space. The rabbits then breathed heliox, oxygen, or room air for 2 hours. Chest radiography was performed 5 minutes after induction of pneumothorax, then at 1 and 2 hours. We determined pneumothorax size on the chest radiograph by measuring the interpleural distance and expressing it as a percentage of the hemithorax.

RESULTS

At 2 hours the pneumothoraces in the heliox group had diminished from 17.50% +/- .50% to .17% +/- .29%; in the oxygen-breathing group they had diminished from 17.83% +/- 2.25% to .50% +/- .50%; and in the air-breathing group they had diminished from 18.50% +/- 3.12% to 17.33% +/- .25%. The difference between the air-breathing and the oxygen-breathing or heliox-breathing animals was highly significant; no significant difference was found between the oxygen and heliox groups (P<.0001).

CONCLUSION

Heliox, a safe and convenient therapy, is as effective as oxygen in reducing the volume of an experimental pneumothorax in rabbits.

Interleukin-1beta levels in serum and cerebrospinal fluid of children with febrile seizures

We compared interleukin-1beta (IL-1beta) levels in peripheral blood and cerebrospinal fluid (CSF) of children with febrile seizures with those of children with febrile illnesses without seizures (control). Twenty patients were included in the study, 10 with febrile seizures and 10 with febrile illness not complicated by seizures (control). Blood and CSF were obtained after the patients' admission to the hospital. IL-1beta levels were measured by a specific radioimmunoassay method. No significant differences were observed between mean IL-1beta levels in CSF (4.15 +/- 1.5 pg/ml) and blood (2.92 +/- 2.6 pg/ml) of the patients with febrile seizures group as compared with those in CSF (3.2 +/- 3.2 pg/ml) and blood (3.44 +/- 3.16 pg/ml) in the control group. These results do not support the hypothesis that increased production of IL-1beta or increased diffusion of IL-1beta through the blood-brain barrier is involved in the pathogenesis of febrile seizures in children.

Incidence of recurrent intussusception following barium versus air enema

The aim of this study was to determine whether using air enema for acute intussusception is related to a higher rate of recurrence than other methods of treatment. A 10-y (1986-95) retrospective study was performed in a university-affiliated paediatric division. The overall recurrence rate for 97 patients with acute intussusception was 7.8% (10% of whom were treated non-surgically). There were no recurrences following the surgical treatment. In matched groups of patients, no risk factors were found for recurrence following air vs barium enema.

Bacteriology of cholelithiasis in infants and children

Today, laparoscopic cholecystectomy is rapidly replacing traditional cholecystectomy as the standard treatment of symptomatic cholelithiasis in children. We reviewed the bile cultures and postoperative course of 30 children who underwent laparoscopic cholecystectomy with the aim of establishing a routine policy for perioperative antibiotic treatment and for the management of biliary leak during that procedure. A positive bile culture was found in only one child (Salmonella Group D). All patients, including six children with intraoperative bile spillage, had a completely normal and uneventful postoperative course. We concluded that the use of preoperative antibiotic treatment should be limited in laparoscopic cholecystectomy in children and is probably not required at all, awaiting proof from a further study. The present study further showed that intraoperative bile spillage is of no clinical significance and can be treated simply with local saline irrigation during the laparoscopic procedure.

Intussusception: a 9-year survey (1986-1995)

BACKGROUND

Acute intussusception has different clinical features in various parts of the world. The goal of this study was to determine the clinical presentation in different ethnic groups in Israel.

METHODS

A retrospective chart review of a 9-year period (1985-1995) was carried out at a university medical center. Data extracted included age, sex, ethnic origin, presenting symptoms and signs, the type of enema (barium or air), and the success rate of non-surgical reduction of the intussusception.

RESULTS

Ninety patients suffering from intestinal obstruction due to acute intussusception were admitted. The triad of intermittent screaming attacks, lethargy, and vomiting was observed in 37.5% of study subjects. The majority of patients were admitted during the warmer months of the year. The average age of the patients was 7.8 +/- 3.7 months; 70% of them were between the ages of 4 and 9 months and 92.5% under 1 year of age. The female-to-male ratio was 1:2.1. Air enema was superior to the barium enema in achieving reduction (p < 0.01). The incidence in the Jewish population was similar to that observed in other surveys, and twice that found in the Arab population in our region (p < 0.05).

CONCLUSIONS

The overall clinical presentation of acute intussusception found in our study does not differ from other studies. The lower incidence of acute intussusception found in the Arab population can be explained by ethnic, genetic, or nutritional factors.

Visual evoked potentials: a diagnostic test for migraine headache in children

Visual evoked potentials (VEPs) were performed in a blind fashion in 114 children aged 3 to 17 years with different types of headaches, in order to investigate whether this could be helpful in the diagnosis of migraine versus other types of headaches in children. The study showed that the amplitude between P100 and N2 was significantly larger in children with migraine headaches (mean 19.8 microvol, SD 7.75) compared with other types of headaches (mean 13.1 microvol, SD 7.45). These results suggest that the sensitivity of VEP P100 amplitude to distinguish migraine headaches in children is 67%, the specificity of VEP is 83%, and the predictive positive value is 83%. VEP study might be helpful in work-up of a child with headache, particularly a young child, when signs and symptoms may not be characteristic.

Postural stability by computerized posturography in minor head trauma

Mild head injuries are very common among young children. Often, these injuries are followed by a variety of subjective complaints termed posttraumatic syndrome. Posturography (balance test) was performed immediately after the trauma in 21 children who had sustained mild head injury. Significant difference in performance was observed in head-injured children in all subparts of the test as compared with a control group. We conclude that posturography may serve as a simple cost-effective method in qualifying the posttraumatic imbalance.

Urinary tract infection following ritual Jewish circumcision

Circumcision seems to reduce the overall incidence of urinary tract infections (UTI), although a few studies have suggested that ritual circumcision may be a predisposing factor for UTI within the first 2 weeks following the procedure. The aim of this study was to investigate a possible causal relationship between ritual circumcision and UTI. The study comprised 82 infants with UTI, 55 females and 27 males under the age of 1 year. All males were circumcised on the eighth day of life. The median age of infection was 0.75 and 7.0 months for males and females, respectively. Fifty-two percent (14/27) of UTI episodes were diagnosed within the 2 weeks following circumcision. A significantly lower incidence in Escherichia coli-induced UTI was observed in males compared to females, 67% and 93%, respectively. Similarly, the incidence of E. coli-induced UTI was also significantly lower in males presenting within 2 weeks following circumcision (57%) compared to infants presenting prior or more than 2 weeks following the procedure (92%). Positive blood cultures of an identical microorganism were observed in 6/27 males compared to 2/55 females. The incidence of urinary tract malformations and their severity were similar in both sexes. We conclude that the high incidence of UTI following a ritual Jewish circumcision, as well as the relatively high preponderance of bacteria other than E. coli, may suggest a causal relationship between circumcision and UTI.

Role of the gut in the pathophysiology of extrahepatic biliary obstruction

BACKGROUND

Gram negative septic events are the commonest source of morbidity and mortality as a result of surgery in jaundiced patients. The large intestine provides the major source of Gram negative bacteria in mammals and is implicated in the pathogenesis of systemic endotoxaemia in obstructive jaundice. Bile salts have an important part in maintaining indigenous microecological homeostasis through their emulsifying properties.

AIMS

The aim was to investigate the effects of biliary obstruction and isolated external biliary diversion on gastro-intestinal structure and caecal bacterial flora in relation to bacterial translocation.

METHOD

Six groups of adult male Wistar rats were studied (no operation, sham operated, and bile duct ligated (BDL) for one and three weeks and a choledocho-vesical fistula (CDVF) for one week). At the end of the study period plasma was assayed for evidence of endotoxaemia and the animals were tested for bacterial translocation to the mesenteric lymph node complex (MLNC), liver, lungs, and spleen. Quantitative and qualitative bacteriological studies were performed on the caecal contents and segments of colon and terminal ileum were washed and prepared for histological assessment.

RESULTS

Bacterial translocation was significantly increased in the BDL1 (68.8%) and BDL3 (60%) groups compared with the sham1 (6.3%), sham3 (9.1%), No operation (0%), and CDVF1 (16.7%) groups. Although translocation was more pronounced in the BDL1 group, this was almost exclusively to the MLNC compared with the more widespread translocation to other organs in the BDL3 group. The BDL3 group was the only group with significantly raised concentrations of endotoxin and anticore glycolipid. The caecal Gram negative aerobic counts were significantly increased in the BDL1 and CDVF1 groups compared with all other groups. There was evidence of structural abnormalities in the terminal ileum of rats jaundiced for three weeks, but not in the other groups.

CONCLUSIONS

Biliary obstruction for one and three weeks promotes bacterial translocation although the mechanisms may be different. Absence of intralumenal bile results in a significant but self limiting increase in the Gram negative aerobic population, which may account for translocation in the early stages of biliary obstruction. As the duration of biliary obstruction increases systemic endotoxaemia is a consistent feature which, combined with factors such as immunological depression and physical disruption of gut barrier function, may promote bacterial translocation perpetuating systemic sepsis.

Dumping syndrome following Nissen fundoplication, diagnosis, and treatment

We evaluated the prevalence, diagnosis, and treatment of dumping syndrome (DS) following Nissen fundoplication in 50 consecutive infants and children who underwent the operation for gastroesophageal reflux. Examination included a preoperative dietary assessment with emphasis on specific postprandial clinical symptoms and technetium scintigraphy to evaluate gastric emptying. In the immediate postoperative period, postprandial glucose levels were examined in all patients with symptoms clinically suggestive of DS. In the late postoperative period (6 months to 5.5 years), all patients with more than one specific clinical symptom of DS were further evaluated by glucose tolerance test (GTT), HbA1C levels, and gastric technetium scintigraphy. DS was diagnosed in 15 patients (30%). Five patients had immediate severe DS (SDS), and 10 in the late postoperative course had latent postoperative DS (LDS). In all patients with DS, preoperative and postoperative gastric emptying scan T1/2 did not show any statistical significance. High levels of HbA1C ranging from 7.9 to 9% (mean, 8.25 +/- 0.5) were found in only three patients. Treatment included parenteral nutrition in one patient. All the others were successfully managed with nutritional manipulation alone, using a combination of lactose-free formula and fat emulsion. In patients whose postprandial symptoms persisted, pectin 5-15 g/day divided into six doses was added to the diet. Following 6 months of dietary treatment, the postprandial normoglycomic response was restored. Eleven patients experienced complete resolution of symptoms (78.5%), and three patients (21.4%) showed significant clinical improvement. This study indicates that DS is a common complication following Nissen fundoplication. The GTT is the most reliable examination for establishing the diagnosis. Treatment is simple and effective. The technetium gastric emptying scan and HbA1C level do not play a significant role in the diagnosis.

Routine childhood screening for hyperlipidemia in Israel

Screening of children and adolescents for hyperlipidemia is controversial. We performed a cholesterol surveillance study of 806 children aged between 6 and 14 years. The initial cholesterol screening test was done by finger stick in the non-fasting state. Children with cholesterol values exceeding 4.55 mmol/l ("borderline" risk) and their parents had their lipid profiles measured following a 12 h fast by venipuncture. The incidence of coronary risk factors in the families of children with hypercholesterolemia was estimated. Of the initial group, 71 children had total capillary cholesterol levels > or = 4.55 mmol/l, and in 65 of these children serum lipid profile was reexamined after an overnight fast. Fifty-five children were found to have total venous cholesterol (TVC) levels < 4.55 mmol/l, and 27 of the 55 had a low density lipoprotein (LDL) cholesterol level > 3.4 mmol/l ("borderline" risk). A positive correlation was found between TVC and LDL-cholesterol levels. Of the hypercholesterolemic children 49% had a parent with hyperlipidemia and 13% had a family history of premature myocardial infarction (before 55 years of age). We conclude that screening of children based on the presence of hypercholesterolemia or its possible complications in other family members may fail to identify many of the children with hypercholesterolemia. Thus, if thorough identification of young children with hypercholesterolemia is desired, inclusive population screening would be the most effective approach.

Severe pseudohypoaldosteronism in a pair of twins not associated with hydramnios

A pair of non-identical twins with severe pseudohypoaldosteronism (PHA) were followed over a period of 4 years. The diagnosis was based on dehydration, hyponatremia, hyperkalemia, high urine sodium/potassium ratios, and high serum concentrations of aldosterone and renin. Sweat and saliva electrolyte concentrations were high, suggesting multifocal target-organ unresponsiveness to mineralocorticoids. No hydramnios was observed during pregnancy. Despite continuous treatment with sodium chloride and sodium bicarbonate (< or = 20 g/day) and cation exchange resin (Kayexalate, sodium polystyrene sulfonate, < or = 4 g/kg per day), the children had repeated episodes of dehydration, hyponatremia, and hyperkalemia. Growth velocity was normal in both twins. Catch-up growth was observed following infancy in the first twin. Normalization of plasma aldosterone, electrolytes, and renin concentrations was achieved at the age of 9 months.

Remifentanil versus alfentanil: comparative pharmacokinetics and pharmacodynamics in healthy adult male volunteers

BACKGROUND

Remifentanil is an esterase-metabolized opioid with a rapid clearance. The aim of this study was to contrast the pharmacokinetics and pharmacodynamics of remifentanil and alfentanil in healthy, adult male volunteers.

METHODS

Ten volunteers received infusions of remifentanil and alfentanil on separate study sessions using a randomized, open-label crossover design. Arterial blood samples were analyzed to determine drug blood concentrations. The electroencephalogram was employed as the measure of drug effect. The pharmacokinetics were characterized using a moment analysis, a nonlinear mixed effects model (NONMEM) population analysis, and context-sensitive half-time computer simulations. After processing the raw electroencephalogram to obtain the spectral edge parameter, the pharmacodynamics were characterized using an effect compartment, inhibitory maximum effect model.

RESULTS

Pharmacokinetically, the two drugs are similar in terms of steady-state distribution volume (VD(SS)), but remifentanil's central clearance (CLc)) is substantially greater. The NONMEM analysis population pharmacokinetic parameters for remifentanil include a CLc of 2.9 l x min(-1), a VDss of 21.81, and a terminal half-life of 35.1 min. Corresponding NONMEM parameters for alfentanil are 0.36 l x min(-1), 34.11, and 94.5 min. Pharmacodynamically, the drugs are similar in terms of the time required for equilibration between blood and the effect-site concentrations, as evidenced by a T(12)k(e0) for remifentanil of 0.75 min [corrected] and 0.96 min for alfentanil. However, remifentanil is 19 times more potent than alfentanil, with an effective concentration for 50% maximal effect of 19.9 ng x ml(-1) versus 375.9 ng x ml(-1) for alfentanil.

CONCLUSIONS

Compared to alfentanil, the high clearance of remifentanil, combined with its small steady-state distribution volume, results in a rapid decline in blood concentration after termination of an infusion. With the exception of remifentanil's nearly 20-times greater potency (30-times if alfentanil partitioning between whole blood and plasma is considered), the drugs are pharmacodynamically similar.

Renal and absorptive hypercalciuria: a metabolic disturbance with varying and interchanging modes of expression

BACKGROUND

In previous studies, the oral calcium loading and deprivation test has been used to distinguish between children with renal (fasting) hypercalciuria (RH) and absorptive hypercalciuria (AH).

OBJECTIVE

We evaluated the long-term clinical course of 30 children with idiopathic hypercalciuria and investigated the influence of urinary sodium excretion, as a reflection of its intake, on urinary calcium excretion.

METHODS

Thirty normocalcemic, normophosphatemic children (21 boys and 9 girls) with urinary calcium to creatinine ratios greater than 0.57 mmol/L/mmol/L ( > 0.21 mg/dL/mg/dL on the three consecutive examinations participated in this study. They were divided according to their responses to calcium deprivation and loading into AH (16 patients) and RH (14 patients).

RESULTS

When restudied 3 to 7 years later, 6 of the 16 children with AH were normocalciuric and three demonstrated characteristics compatible with RH. The remaining seven patients maintained their initial AH pattern. Of the 14 children with RH, four were normocalciuric and four demonstrated AH. The remaining six children maintained their initial RH pattern. A significant positive correlation was observed between urine sodium and calcium excretion in children with AH or RH. Children who were normocalciuric at the second study had significantly lower values of urine sodium excretion when compared with those in whom hypercalciuria persisted.

CONCLUSIONS

We suggest that AH and RH constitute a continuum. The change in characteristics observed during the second study suggests that any attempt to divide these patients into two physiologically distinct subtypes may be artificial. The main factor influencing urinary excretion of calcium in our patients seemed to be sodium intake.

Subcuticular skin closure as a standard approach to emergency appendectomy in children: prospective clinical trial

We evaluated the morbidity associated with primary closure by interrupted subcuticular absorbable sutures following emergency appendectomy. In a prospective clinical trial over a 12-month period, 216 children who underwent emergency appendectomy had skin closure using subcuticular interrupted absorbable polyglactin 4-0 sutures. Preoperative prophylactic antibiotics consisting of metronidazole alone or in combination with gentamicin were used in patients with suspected phlegmonous appendicitis; a combination of metronidazole, gentamicin, and ampicillin was used when perforation of the appendix was suspected. Postoperatively, in patients with phlegmonous appendicitis metronidazole was given for 24 hours, whereas in those with peritonitis the triple antibiotics were continued for 7 to 10 days. All patients were assessed for complications resulting from the technique of wound closure. No intraabdominal abscesses or serious complications were recorded. The overall incidence of wound infection was 1.8%. Among children with a perforated appendix the rate of superficial wound infection was 5.7%. There was no difference in the rate of wound infection between patients who received metronidazole alone or metronidazole plus gentamicin preoperatively. All the patients and their families were satisfied with the cosmetic results and with the fact that removal of skin sutures was unnecessary. We conclude that the use of prophylactic antibiotics permits standard skin closure by interrupted absorbable subcuticular suture.

Peritoneal ventilation in rabbits: augmentation of gas exchange with cisapride

BACKGROUND

Peritoneal ventilation has been shown to be effective in achieving extrapulmonary oxygenation and carbon dioxide elimination in an animal model of severe adult respiratory distress syndrome (ARDS). Cisapride is a "prokinetic" agent (increases gastric emptying), that may increase the splanchnic circulation and thus favourably affect gas exchange in peritoneal ventilation.

METHODS

Using Doppler ultrasound the effect of cisapride on the portal venous circulation was examined in eight spontaneously breathing rabbits and the effect of cisapride on gas exchange in five rabbits spontaneously breathing room air was compared with that of a control group who did not receive cisapride. Its effect on gas exchange in five rabbits with ARDS being treated with mechanical lung and peritoneal ventilation was compared with that of a control group, and its effect on gas exchange in five rabbits with ARDS treated with conventional ventilation was also compared with that of a control group.

RESULTS

Enteral administration of cisapride increased portal venous blood velocity, as measured ultrasonographically, by a mean of 188% one hour after receiving the drug. In rabbits with ARDS being treated with both peritoneal ventilation and mechanical ventilation to the lungs, those receiving cisapride had arterial oxygen tensions 1.5-3 times that of controls. Cisapride had no effect on arterial blood gas tensions in rabbits who were spontaneously breathing room air, nor in rabbits with ARDS who received only conventional mechanical lung ventilation.

CONCLUSIONS

Cisapride increases arterial oxygenation in rabbits with severe ARDS treated with peritoneal ventilation, probably due to its ability to increase splanchnic circulation. It should be considered as an adjuvant medication to peritoneal ventilation.

Characterisation of the interaction between the nucleoprotein and phosphoprotein of pneumonia virus of mice

A protein blotting technique was used to study the interaction occurring between the pneumonia virus of mice N protein and other PVM encoded proteins expressed in infected cells. Measurement of the degree of binding indicated that the N protein specifically interacted only with the full-length 39 kDa P protein in infected cells. Truncated N-related proteins were synthesised in vitro and incubated with filter-bound full-length and truncated P proteins. The data suggested that many regions of the N protein are cooperatively involved in the binding process. It was also determined that both the amino and the carboxyl-terminal regions of the PVM P protein were essential for binding to N protein.

Effects of adrenaline and hyaluronidase on plasma concentrations of lignocaine and bupivacaine after peribulbar anaesthesia

We have measured peak plasma concentrations of lignocaine and bupivacaine after dual injection peribulbar block and investigated the influence of adrenaline and hyaluronidase. Twenty-four patients were allocated randomly to one of four groups: (I) local anaesthetic alone (lignocaine 10 mg ml-1-bupivacaine 3.75 mg ml-1); (II) local anaesthetic with adrenaline (5 micrograms ml-1); (III) local anaesthetic with hyaluronidase (75 iu ml-1); or (IV) local anaesthetic with adrenaline and hyaluronidase. Venous plasma concentrations of lignocaine and bupivacaine were measured in 24 patients using gas liquid chromatography before and at 5, 10, 15, 20, 25, 30, 45, 60, 90, 120, 180, 300 and 540 min after completion of the peribulbar injections. Main outcome measures were analysed using two-way analysis of variance. All patients, with one exception, received 10 ml of the local anaesthetic mixture. Overall peak plasma concentrations varied from 230 to 1910 micrograms ml-1 for lignocaine and from 160 to 1090 micrograms ml-1 for bupivacaine. Adrenaline significantly reduced peak plasma concentrations of lignocaine to 57% (P = 0.001) and bupivacaine to 61% (P = 0.004) compared with the nonadrenaline groups. Hyaluronidase had no significant effect on peak plasma concentrations of lignocaine and bupivacaine, which were 90% (P = 0.34) and 100% (P = 0.84) of the non-hyaluronidase groups. The area under the plasma concentration-time curves to 300 min (AUC300) behaved similarly. There was a reduction in AUC300 for lignocaine (P = 0.005) and bupivacaine (P = 0.011) in the adrenaline groups compared with the non-adrenaline groups, in contrast with no significant effects of hyaluronidase on AUC300 for lignocaine (P = 0.14) or bupivacaine (P = 0.53) compared with the non-hyaluronidase groups.

Investigative approach to frog gastrocnemius laboratory: potential impact on animal use in teaching laboratories

With growing concern over the use of animal experimentation in the teaching of physiology, many biology departments are reassessing the use of animal experiments in the teaching lab. However, it may be just as important to assess how animal experimentation is used in the undergraduate teaching laboratory rather than simply assessing if animal experimentation should be used at all. In our study, sophomore-level life science students enrolled in a core organismal biology course undertook a laboratory exercise designed to elucidate properties of muscles and neuromuscular communication following two protocols: 1) a standard demonstrational model wherein students were told to undertake the exercise as a means to understand physiological processes that they had been exposed to previously in lecture or 2) an investigative model wherein the use of the gastrocnemius preparation was a logical next step in an ongoing investigation, the content of which was driven by student-generated hypotheses. We have observed a significant decrease in a number of the negative comments concerning the use of animals in experimentation (25.6 vs. 3.6%) since the implementation of the investigative approach to the laboratory, suggesting that curricular approaches to the use of animals in the teaching laboratory may have an impact on student attitudes concerning animal experimentation.