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Efficacy of clavulanate-potentiated amoxycillin in experimental and clinical skin infections.

The efficacy of clavulanate-potentiated amoxycillin was compared with amoxycillin alone in experimental staphylococcal infection in dogs and in a controlled trial in clinical cases of skin infection in dogs and cats. The experimental infection was produced by subdermal inoculation with beta-lactamase producing (amoxycillin resistant) staphylococci absorbed in cotton dust. This produced discrete, localised lesions with no systemic involvement. In a cross over study, six animals were randomly allocated to treatment with either amoxycillin alone (10 mg/kg, dosed twice daily) or a formulation of clavulanate-potentiated amoxycillin (12.5 mg/kg, of a 1:4 ratio, dosed twice daily). The lesions of the animals treated with clavulanate-potentiated amoxycillin resolved more quickly than those treated with amoxycillin alone. The difference was significant (P less than 0.05) for both lesion diameter and inflammation score after day 6 of treatment. A trial was carried out in clinical cases of skin disease which were randomly allocated to twice daily treatment with either amoxycillin alone (10 or 20 mg/kg), or with clavulanate-potentiated amoxycillin (12.5 or 25 mg/kg of a 1:4 ratio). The required duration of treatment was shorter (P less than 0.5) for the potentiated amoxycillin treatments, and the success rate (judged by cure or substantial improvement) was higher (P less than 0.05) for this group, especially (P less than 0.01) where amoxycillin resistant organisms were isolated. It was concluded that clavulanate-potentiated amoxycillin was an effective treatment of skin infections both under experimental and clinical conditions.

Amoxicillin↗

Temporal relationship between the onset of oestrus, the preovulatory LH surge and ovulation in farmed fallow deer, Dama dama.

A study was conducted to determine the timing of ovulation relative to the onset of oestrus and the preovulatory LH surge in fallow deer. Mature fallow does were randomly allocated to two treatments (N = 10 per treatment) designed to synchronize oestrus on or about 17 May. Does assigned to Group 1 (prostaglandin-induced oestrus) each initially received single intravaginal CIDR [Controlled Internal Drug Release] devices for 13 days followed by an i.m. injection of 750 mg cloprostenol on Day 12 (15 May) of the subsequent luteal cycle. Does assigned to Group 2 (progesterone-induced oestrus) each received CIDR devices for 13 days, with withdrawal occurring on 15 May. All does were run with crayon-harnessed bucks (10:1 ratio) from the start of synchronization (18:00 h 15 May). Ten does (5 per group) were blood sampled via indwelling jugular cannulae every 2 h for 72 h from cloprostenol injection or CIDR device withdrawal and the plasma was analysed for concentrations of progesterone and LH by radioimmunoassay. Does within each treatment were randomly allocated to an ovarian examination time of 12, 16, 20 or 24 h after the onset of oestrus. Laparoscopy was repeated at 12-h intervals until ovulation was recorded. The ovaries of does failing to exhibit oestrus were examined 72 and 86 h after cloprostenol injection or CIDR device withdrawal. A total of 17 does were observed to exhibit oestrus at a mean (+/- s.e.m.) interval from treatment of 44.6 +/- 3.6 h for Group 1 (N = 9) and 34.1 +/- 2.5 h for Group 2 (N = 8).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Strategies for mastitis control: dry cow therapy and culling.

The effects of three selection strategies for dry cow therapy on prevention of new infections and rate of antibiotic usage were compared. Quarter infection status of 1044 cows in 12 herds was determined by bacteriological methods at drying off, calving and three to five months into the following lactation. Cows that were uninfected at drying off were randomly allocated to treatment (whole udder, dry cow therapy) and non-treatment groups. Infected cows were randomly allocated to whole udder or infected quarter only treatments. The strategies compared were blanket treatment (treat all quarters of all cows), selective cow treatment (treat all quarters of any cow infected in one or more quarters) and selective quarter treatment (treat infected quarters only). Selective cow treatment was identified as the preferred strategy. Blanket treatment resulted in increased antibiotic usage (15.5 vs 6.4 tubes per infection eliminated) with no additional benefit, and selective quarter treatment resulted in a higher new infection rate (6.4% vs 3.9% quarters) in the dry period. The prevalence of infection within a herd at drying off had no influence on new infection rates in the dry period or early lactation. The cure rate after dry cow treatment (mean of 66%) decreased significantly with increasing age (P < 0.001). Cows infected in the previous lactation contributed over 76% of infections at calving and nearly 70% at mid-lactation. To lower the incidence of mastitis in a herd, a greater emphasis on culling of older infected cows and prevention of new infections during lactation is needed.

Animals↗

Renal response to the angiotensin II receptor subtype 1 antagonist irbesartan versus enalapril in hypertensive patients.

OBJECTIVE: To compare the acute and sustained renal hemodynamic effects on hypertensive patients of 100 mg irbesartan and 20 mg enalapril each once daily. PATIENTS: Twenty patients (aged 35-70 years) with uncomplicated, mild-to-moderate essential hypertension and normal serum creatinine levels completed this study. STUDY DESIGN: After random allocation to treatment (n=10 per group), administration schedule (morning or evening) was determined by further random allocation, with crossover of schedules after 6 weeks' therapy. Treatment and administration assignments were double-blind. Twenty-four-hour ambulatory blood pressure was monitored before and after 6 and 12 weeks of therapy. Renal hemodynamics were determined on the first day of drug administration and 12 and 24 h after the last dose during chronic treatment. RESULTS: Administration of each antihypertensive agent induced a renal vasodilatation with no significant change in glomerular filtration rate. However, the time course appeared to differ: irbesartan had no significant acute effect 4 h after the first dose, but during chronic administration a renal vasodilatory response was found 12 and 24 h after the dose; enalapril was effective acutely and 12 h after administration, but no residual effect was found 24 h after the dose. Both antihypertensive agents lowered mean ambulatory blood pressure effectively, with no significant difference between treatments or between administration schedules (morning versus evening). CONCLUSIONS: Irbesartan and enalapril have comparable effects on blood pressure and renal hemodynamics in hypertensive patients with normal renal functioning. However, the time profiles of the renal effects appear to differ, which might be important for long-term renoprotective effects.

Adult↗

Progesterone mediates nutritionally induced effects on embryonic survival in gilts.

The role of plasma progesterone as a potential mediator of nutritionally induced effects on embryonic survival in gilts was assessed in two experiments. Gilts were individually fed 2.5 kg/d for one estrous cycle and inseminated 12 and 24 h after onset of next estrus (d 0). In Exp. 1, 52 gilts were randomly allocated to either N (1.5 x maintenance feed/d) or H (twice maintenance/d) groups from d 1. In 21 gilts, blood samples were collected on d -1, 0, 1, and 2, and gilts were slaughtered on d 3 to 5. Interval from LH peak to postovulatory progesterone rise was shorter (P = .02) in N (28.8 +/- 2.3 h) than in H (38.6 +/- 3.2 h) gilts, with no difference in rate of rise. Embryonic survival was 86.5 +/- 2.1 and 74.2 +/- 6.2% in N and H gilts, respectively, with a higher variability in Group H (P < .05). In 31 gilts, blood samples were collected 48 and 72 h after estrus onset, and gilts were slaughtered on d 11 and 12. Plasma progesterone concentrations at 72 h were higher (P = .02) in N than in H gilts (14.7 +/- 1.2 vs 10.8 +/- 1.0 ng/mL). Uterine plasmin/trypsin inhibitor concentrations were higher (P = .03) in H than in N gilts, but IGF-I concentrations did not differ. In Exp. 2, gilts were randomly allocated to either H or HP groups on d 1. The HP gilts were given six injections of progesterone (75 mg every 12 h) starting 24 h after estrus onset. Gilts were slaughtered on d 28 +/- 3. Plasma progesterone concentrations at 36, 48, 60, 84, and 108 h after estrus onset were higher (P < .001) in HP than in H gilts. Embryonic survival was also higher (P = .004) in HP (84.8 +/- 2.6%) than in H gilts (70.0 +/- 4.0%). Thus, periovulatory plasma progesterone can be the mediator of nutritionally induced effects on embryonic survival.

Animal Nutritional Physiological Phenomena↗

Evaluation of the SprayGel adhesion barrier in the rat cecum abrasion and rabbit uterine horn adhesion models.

OBJECTIVE: To evaluate the efficacy of a new adhesion barrier in the prevention of postoperative adhesion formation. DESIGN: A double-blind controlled study of the efficacy of SprayGel in reducing postoperative adhesion formation in two animal models. SETTING: Animal care facility of a contract testing laboratory. ANIMAL(S): Sixteen Sprague-Dawley male rats were randomly allocated into two groups in the cecum abrasion model. Twenty New Zealand white female rabbits were randomly allocated into two groups in the uterine horn abrasion model. INTERVENTION(S): In the rat model, the cecum was abraded with gauze and the abdominal wall was abraded with a scalpel. Treated animals received SprayGel coating on injured surfaces; control animals received no treatment. In the rabbit model, uterine horns were abraded with a scalpel. Treated animals received SprayGel coating on injured surfaces; control animals received no treatment. MAIN OUTCOME MEASURE(S): Postoperative adhesion formation. RESULT(S): In the rat model, SprayGel was found to significantly reduce the incidence of adhesions, which formed in 7 of 8 control rats compared with 1 of 8 treated rats. In the rabbit model, SprayGel was found to significantly reduce both the extent and severity of adhesions. CONCLUSION(S): Application of SprayGel in two animal models reduced formation of postoperative adhesions. Further investigation in large animal and clinical settings is warranted.

Abdominal Muscles↗

Toxicological consequences of Aroclor 1254 ingestion by female rhesus (Macaca mulatta) monkeys and their nursing infants. Part 3: post-reproduction and pathological findings.

A group of 80 menstruating rhesus (Macaca mulatta) monkeys were randomly allocated to four similar rooms (20 monkeys/room) and then to one of five dose groups (four females/dose group/room). Each day the monkeys self-ingested capsules containing doses of 0, 5, 20, 40 or 80 microg Aroclor 1254/kg body weight. After 25 months of continuous dosing, approximately 90% of the treated females had attained a qualitative pharmacokinetic steady state with respect to the concentration of polychlorinated biphenyl (PCB) in their nuchal fat pad. Concurrently, sebaceous glands were being examined for changes analogous to chloracne. Subsequently, the females were paired with untreated males. The infants' blood PCB levels at birth were not correlated with its dam's dose or blood PCB level. However, there was an association between an infants preweaning blood PCB levels and its dam's dose and PCB milk levels. After weaning, the infants were not dosed with PCB. The half-life for the PCB in the infants' blood was determined and found to be slightly more than 15 wk. After 6 yr on test, three monkeys from the 0, 5, 20 and 40 microg dose groups were randomly allocated to a depletion study to ascertain the half-lives of specific PCB congeners (Mes et al., Chemosphere 1995, 30, 789-800). Concurrently, necropsies began of the remaining females, and of seven infants from the treated dams and four infants from the control dams, which had attained an age of 2 yr. Approximately 3 yr later, the depletion monkeys were necropsied. The only statistically significant treatment-related pathological changes found during the study were in the adult females, in which an involution of the sebaceous glands and a dose related increase in liver weight due to hyperplasia were evident.

Administration, Oral↗

Renal scars and parenchymal thinning in children with vesicoureteral reflux: a 5-year report of the International Reflux Study in Children (European branch).

A total of 321 children less than 11 years old with nonobstructive grade III or IV vesicoureteral reflux and with previous urinary tract infection was randomly allocated to medical or surgical treatment in the European branch of the International Reflux Study in Children. (Randomization was stratified for age, sex, grade of reflux, presence of renal scarring, interval since last urinary tract infection and treating hospital). The results of excretory urography are reported for 233 girls and 73 boys treated according to the random allocation, 89% of whom were followed for 5 years. After 5 years in the medical group (155 children) new renal scars were seen in 19 and new renal parenchymal thinning in 11. The proportions were almost identical among 151 children allocated to surgical treatment with 20 new scars and 15 new thinnings. Progression of established scars was also similar in both groups. However, the new scars developed sooner after surgery than during medical treatment. In 6 surgically treated children postoperative obstruction was followed by the development of new scars. In addition, 12 patients showed new scars approximately 6 months after successful surgery, while in only 2 children scars developed more than 6 months after surgery. In 11 children of the medical group new scars were seen more than 6 months after allocation. More new scars developed in the children with parenchymal thinning at entry (23%) than in those with scarred or normal kidneys at entry (10% each) (p < 0.05). The younger the patients at entry, the higher the frequency of new scars (less than 2 years 19.8%) 2 to 4 years 9.8% and 5 years or more 4.6%, p < 0.05).

Child↗

Effects of octreotide on acute pancreatitis of varying severity in rats.

OBJECTIVE: To find out the effects of the octreotide on the course of acute pancreatitis in rats. DESIGN: Prospective laboratory study. SETTING: Medical school, Turkey ANIMALS: 184 Sprague-Dawley rats, 120 of which were randomly allocated into 8 groups of 15 each for the survival study, and the remainder of which were randomly allocated into 8 groups of 8 rats each for assessment of biochemical variables and histological score. INTERVENTIONS: The same 8 groups were used for the two parts of the study: saline alone (control), octreotide alone (control), oedematous pancreatitis induced by cerulein with and without octreotide, moderate pancreatitis induced by low-dose glycodeoxycholic acid and cerulein with and without octreotide, and severe pancreatitis induced by high-dose glycodeoxycholic acid and cerulein with and without octreotide. MAIN OUTCOME MEASURES: Mortality, results of biochemical tests, and histological score. RESULTS: No rats in the control groups died. Of those with oedematous pancreatitis 1 died that had not been given octreotide (7%) and 2 that had (13%). In the moderate pancreatitis groups 4 that had not been given octreotide died (27%) compared with one that had (7%). In the severe pancreatitis group 7 that had not had octreotide died (46%) compared with 6 that had (40%). Octreotide caused a reduction in serum amylase and lactate dehydrogenase activity in all groups, but reduced aspartate aminotransferase only in those rats with moderate pancreatitis. It prevented hypocalcaemia in rats with severe pancreatitis, but had no effect on serum electrolyte concentrations, alkaline phosphatase activity, or blood gas analyses. Rats with moderate pancreatitis that had been given octreotide had less tissue oedema, acinar necrosis, and inflammatory cell infiltration. In those with severe pancreatitis there was less tissue oedema but more acinar necrosis. CONCLUSION: If octreotide is given early in the course of the disease it may result in improved outcome, but it seems to be ineffective in severe pancreatitis in which acinar necrosis is already established.

Acute Disease↗

Effects of losartan and its combination with quinapril on the cardiac sympathetic nervous system and neurohormonal status in essential hypertension.

OBJECTIVE: Sympathetic nervous and renin-angiotensin systems play important roles in essential hypertension. This study was aimed at assessing the effects of losartan or its combination with quinapril on the cardiac nervous system and neurohormonal status in essential hypertension. DESIGN AND METHODS: Randomized, comparative study of 105 patients with mild essential hypertension, carried out at Shizuoka General Hospital. In phase 1, 40 hypertensives were allocated randomly into the losartan (50 mg) group or the quinapril (10 mg) group. In phase 2, 65 hypertensives, after 3 months 10 mg quinapril monotherapy, were allocated randomly into groups with 50 mg losartan (n = 32) or 5 mg amlodipine (n = 33) added to quinapril, and were treated for a further 3 months. All patients underwent [(123)I]metaiodobenzylguanidine (MIBG) imaging and neurohormonal measurements before and 3 months after treatment. RESULTS: Both monotherapies significantly increased renin activity, while losartan monotherapy also increased angiotensin II (AII) concentration. In both the losartan and quinapril groups, the washout rate was significantly decreased (18.1 +/- 11.4 versus 13.9 +/- 11.0%, P < 0.0002 and 13.3 +/- 9.3 versus 12.3 +/- 9.1%, P < 00001, respectively) without changes in the heart to mediastinum ratio (H/M ratio). Both combined therapies lowered blood pressure to similar levels. A combination therapy with losartan and quinapril significantly increased the H/M ratio (1.93 +/- 0.29 and 2.02 +/- 0.29, P < 0.01) and decreased the washout rate (17.6 +/- 11.0 and 15.3 +/- 9.2%, P < 0.02) without affecting AII concentration, whereas a combination therapy with amlodipine and quinapril therapy did not affect the scintigraphic parameters with an increase in the AII concentration. CONCLUSIONS: With a usual antihypertensive dose, both losartan and quinapril had a little suppressive effect on the cardiac sympathetic activity in essential hypertension. In contrast, the combination therapy with losartan and quinapril, which results in a higher degree of inhibition of the renin-angiotensin system, could suppress the cardiac sympathetic activity effectively.

3-Iodobenzylguanidine↗

Safety, immunogenicity, and transmissibility of single-dose live oral cholera vaccine strain CVD 103-HgR in 24- to 59-month-old Indonesian children.

Recombinant A-B+ Vibrio cholerae O1 strain CVD 103-HgR is a safe, highly immunogenic, single-dose live oral vaccine in adults in industrialized countries. Safety, excretion, immunogenicity, vaccine transmissibility, and environmental introduction of CVD 103-HgR were investigated among 24- to 59-month-old children in Jakarta. In 81 households, 1 child was randomly allocated a single dose of vaccine (5 x 10(9) cfu) and another, placebo. Additionally, 139 unpaired children were randomly allocated vaccine or placebo. During 9 days of follow-up, diarrhea or vomiting did not occur more often among vaccines than controls. Vaccine was minimally excreted and was isolated from no controls and from 1 (0.6%) of 177 unvaccinated family contacts. A 4-fold or higher rise in serum vibriocidal antibody was observed in 75% of vaccines (10-fold rise in geometric mean titer over baseline). Of 135 paired placebo recipients or household contacts, 5 had vibriocidal seroconversions. Moore swabs placed in sewers and latrines near 97 households failed to detect vaccine. These observations pave the way for a large-scale field trial of efficacy.

Antibodies, Bacterial↗

Emergency hospital admissions and readmissions of patients aged over 75 years and the effects of a community-based discharge scheme.

This paper reports the results of a retrospective review which analysed emergency admissions and readmissions of elderly patients to a district general hospital. All patients received standard after-care allocated by the community health and social services departments following referral by hospital staff. In addition, half of the cohort was randomly allocated to receive care attendant support for a maximum of 12 hours a week for two weeks following the first and any subsequent discharge from hospital. The effect of this additional community support on emergency readmissions was also reviewed. The findings show that the patients randomly allocated to receive the modest domiciliary after-care service were less likely to have another emergency readmission or multiple readmissions. The results suggest that patients over 75 years-of-age, living alone, or having two or more emergency admissions within six months, should have a domiciliary assessment and follow-up after hospital discharge.

Aftercare↗

Stapled and open hemorrhoidectomy: randomized controlled trial of early results.

The aim of the study was to compare the early results in 52 patients randomly allocated to undergo either stapled or open hemorrhoidectomy. Seventy-four patients with grade III and IV hemorrhoids were randomly allocated to undergo either stapled (37 patients) or open (37 patients) hemorrhoidectomy. Stapled hemorrhoidectomy was performed with the use of a circular stapling device. Open hemorrhoidectomy was accomplished according to the Milligan-Morgan technique. Postoperative pain was assessed by means of a visual analogue scale (V.A.S.). Recovery evaluation included return to pain-free defecation and normal activities. A 6-month clinical follow-up and a 17.5 (10 to 27)-month median telephone follow-up was obtained in all patients. Operation time for stapled hemorrhoidectomy was shorter (median 25 [range 15 to 49] minutes versus 30 [range 20 to 44] minutes, p = 0.041). Median (range) V.A.S. scores in the stapled group were significantly lower (V.A.S. score after 4 hours: 4 [2 to 6] versus 5 [2 to 8], p = 0.001; V.A.S. score after 24 hours: 3 [1 to 6] versus 5 [3 to 7], p = 0.000; V.A.S. score after first defecation: 5 [3 to 8] versus 7 [3 to 9], p = 0.000). Resumption of pain-free defecation was significantly faster in the stapled group (10 [6 to 14] days vs 12 [9 to 19] days, p = 0.001). At follow-up 4 weeks and 6 months postoperatively the median (range) symptom severity score was similar in both groups (1 [0 to 2] versus 0 [0 to 3], p = 0.150 and 0 [0 to 2] versus 0 [0 to 2], p = 0.731). At long-term follow-up occasional pain was present in 6/37 (16.2) patients in the stapled group and 7/37 (18.9%) in the Milligan-Morgan group (p = 1.000); episodes of bleeding were reported by 8/37 (21.6%) patients in the stapled group and 5/37 (13.5%) patients in the Milligan-Morgan group (p = 0.542). No problems related to continence and defecation were reported in either group. Patients were satisfied with the operation in 33/37 (89.2%) cases in the stapled group and 31/37 (83.8%) cases in the Milligan-Morgan group (p = 0.735). Hemorrhoidectomy with a circular staple device is easy to perform and achieves better results than the Milligan-Morgan technique in terms of postoperative pain and recovery. Comparable results are obtained at long-term follow-up.

Adult↗

Role of nitric oxide and oxidative stress in baroreceptor dysfunction in patients with chronic heart failure.

Abnormalities of autonomic control of the cardiovascular system are seen in chronic heart failure (CHF) and confer a poor prognosis. Nitric oxide appears to be important in the regulation of baroreflex control in health and in disease states. The antioxidant vitamin C increases nitric oxide bioavailability in CHF. We evaluated the effects of vitamin C on baroreceptor sensitivity (BRS) by sequence analysis in 100 CHF patients and 44 control subjects. Groups of 55 CHF patients and 22 controls were randomly allocated to receive a single intravenous injection of vitamin C (2 g) or placebo. In addition, 45 CHF patients were randomly allocated to receive a 4-week course of oral vitamin C (4 g/day) or placebo. An age-related reference range for BRS was developed in 22 healthy controls matched for age and gender to the CHF group. BRS was significantly impaired in the CHF group compared with age-matched older controls and young controls (6.9 +/- 3.1, 12.5 +/- 4.9 and 21.7 +/- 9.1 mmHg/ms respectively; P < 0.001 between groups). Intravenous vitamin C acutely improved BRS in CHF patients by 24% (by 1.8 +/- 4.1 mmHg/ms; P < 0.05), but not in controls. There was no improvement in BRS in CHF patients given chronic oral vitamin C. Thus acute intravenous, but not chronic oral, vitamin C improved BRS in CHF patients. There was no effect of intravenous vitamin C in healthy subjects, suggesting that the mechanism was either by free radical scavenging or due to central effects.

Administration, Oral↗

QT dispersion increases during intubation in patients with coronary artery disease.

Anesthetic drugs have been shown to increase QT interval, however data regarding their effects on QT dispersion (QTd) are scarce, especially in patients with coronary artery disease (CAD). We tested whether induction of Anesthesia with thiopental and etomidate would increase QTd in patients with CAD. Thirty American Society of Anesthesiologists (ASA) physical status I-II patients without CAD were randomly allocated to groups I (n = 15) and II (n = 15) and 30 ASA physical status III patients with CAD were randomly allocated to groups III (n = 15) and IV (n=15). Anesthesia was induced with thiopental 5-7 mg/kg IV in groups I and III and with etomidate 0.2-0.3 mg/kg IV in groups II and IV. Endotracheal intubation was facilitated with vecuronium bromide 0.1 mg/kg IV. Twelve-lead electrocardiogram (ECG) was recorded in all patients at baseline (ECG(1)), 1 min after the induction agent (ECG(2)), 1 min (ECG(3)) and 5 min (ECG(4)) after intubation. Anesthesia was maintained with isoflurane and nitrous oxide in 34 % oxygen after ECG(2) recording. QTd and corrected QT dispersion (QTcd) were calculated. In patients with CAD induced with thiopental, QT dispersion increased significantly during the intubation period compared with baseline (from 43.0 +/- 25.6 ms to 69.2 +/- 25.3 ms; P <.01). Likewise, QT dispersion also increased during intubation in patients with CAD induced with etomidate (from 41.5 +/- 17.2 ms to 80.0 +/- 33.6 ms; P <.001). There was no increase in QT dispersion in patients without known CAD. QT dispersion seems to be increased during the intubation period in patients with CAD regardless of the induction agents used.

Aged↗

The relationship between odontogenic bacteraemia and orthodontic treatment procedures.

The purpose of this research was to estimate the prevalence and intensity of bacteraemia associated with orthodontic treatment procedures. The four procedures investigated were: an upper alginate impression, separator placement, band placement, and adjustment of an archwire on a fixed appliance. Eighty-one children undergoing general anaesthesia (GA) for dento-alveolar surgery related to their orthodontic treatment were randomly allocated to the impression or separator group. A further 61 children, receiving treatment in the Outpatient Department, were included and randomly allocated to the banding or archwire adjustment groups. A cannula was inserted into either the left or right antecubital fossa using an aseptic technique. A baseline 6 ml sample of blood was taken before treatment and a second 6 ml sample was taken 30 seconds after the procedure. There was no significant difference in the number of positive blood cultures between baseline (nine, 23 per cent), and following an upper alginate impression (twelve, 31 per cent); between baseline (twelve, 27 per cent), and placement of a separator (fifteen, 36 per cent); between baseline (nine, 36 per cent), and fitting or placement of a band (eleven, 44 per cent); or between baseline (twelve, 33 per cent), and archwire adjustment (seven, 19.4 per cent). For the separator group only the mean total number of aerobic and anaerobic bacteria combined, isolated from the blood samples (cfu of bacteria per ml of blood), was significantly greater following the placement of a separator (2.2, SD 9.1), compared with baseline (0.9, SD 0.2; P < 0.02). This investigation demonstrates that the only orthodontic treatment procedure that causes a significant bacteraemia is the placement of a separator.

Adolescent↗

Nitrous oxide produces a non-linear reduction in thiopentone requirements.

We studied 88 healthy, ASA I patients (aged 20-45 yr), to determine if nitrous oxide affects thiopentone requirements for achieving 50% probability of no movement in response to verbal commands (CP,50). Patients were allocated randomly to one of four nitrous oxide concentration groups (0%, 20%, 40% and 60%). Patients in each group were also allocated randomly to receive predetermined target plasma concentrations of thiopentone. Computer-controlled continuous infusion was used to maintain the target plasma thiopentone concentration, and this concentration was held constant for 6 min to ensure equilibration. The CP,50, value of thiopentone in the absence of nitrous oxide was 14.8 micrograms ml-1. The reduction in CP,50 by nitrous oxide was non-linear, and the interaction coefficient between nitrous oxide and thiopentone was significantly smaller than zero (P = 0.0274), indicating that nitrous oxide antagonized the ability of thiopentone to prevent response to verbal commands.

Adult↗

Efficacy of ivermectin in oral drench and paste formulation against migrating larvae of experimentally inoculated Parascaris equorum.

Twenty-one mixed-breed pony foals, reared and maintained under parasite-free conditions, were used to test the efficacy of ivermectin in oral drench and paste formulations (200 micrograms/kg) against 11-day-old migrating larvae of Parascaris equorum. Three replicates of 4 foals and 3 replicates of 3 foals were formed on the basis of age. Foals in replicates of 4 were randomly allocated to be indicators, or to receive vehicle (control) or ivermectin paste or ivermectin liquid. Foals in replicates of 3 were randomly allocated to receive vehicle or ivermectin paste or ivermectin liquid. The recovery of larvae from the lungs, liver, and small intestines of the indicator foals showed that 99.9% of the larvae were in the lungs 11 days after inoculation (day 0 of treatment). The recoveries of larvae from lungs and small intestines of controls at 25 days after inoculation indicated that all larvae had migrated to the small intestine by this time. The mean length of larvae recovered from the lungs (11 days after inoculation) was 0.87 mm the mean length of those recovered from the small intestine (25 days after inoculation) was 3.65 mm. Using larvae recovered from small intestinal contents for calculations, ivermectin in both formulations was 100% effective against 11-day P equorum (P less than 0.01, compared with control group geometric mean of 1498.4).

Animals↗