Exploration of the common bile duct for stones: the influence of the flexible choledochoscope and perioperative antibiotic prophylaxis

A retrospective study of 110 patients, out of a total of 743 open cholecystectomies, who have undergone common bile duct (CBD) exploration for stones between 1985 and 1990. CBD exploration was performed in the presence of abnormal peroperative cholangiogram in 86 (78%) patients. The remaining 24 patients were known to have either an abnormal preoperative ERCP or palpable ductal stones at the time of surgery. Post exploratory choledochoscopy was performed as an additional completion procedure in 58 (53%) patients and it identified further stones in 28 (48.3%) of these patients. There were three patients in whom no stones were identified on exploration of the CBD. Documented evidence of peroperative antibiotic prophylaxis was obtained in 78 (71%) patients. A total of 27 (24.5%) patients developed complications including seven (6.4%) patients with retained stones. In four of these patients with retained stones, flexible choledochoscopy was undertaken as an additional completion procedure to ensure ductal clearance. Cardiorespiratory and septic complications were the next most common problems occurring in 6.5% and 5.4% respectively, of patients reviewed. In conclusion, the retained stone rate has fallen from 14% in 1987 to 6.4% in this study. The choledochoscope has influenced this as it identified further residual stones following conventional exploration. The sepsis rate has also fallen from 19.5% to 4.5% in this study. We believe this is due to the use of antibiotic prophylaxis.

Novel hypotheses for the roles of EBNA-1 and BHRF1 in EBV-related cancers

Epstein-Barr virus has been linked to several types of human cancer including Burkitt's lymphoma and nasopharyngeal carcinoma but the mechanisms by which the virus might contribute to cancer remain obscure. Here we consider the possibility that EBNA-1, which is expressed in both tumours, directly transactivates cell genes. The EBNA-1 protein was tested for transcription transactivation domains and the human genome was screened for high-affinity EBNA-1-binding sites that might mediate transactivation. None were found, although novel low-affinity-binding sites in the EBV genome were detected. We also investigated the expression of BHRF1, the viral homologue to bcl-2, in epithelial cells and showed that it is expressed in vivo in the EBV replication found in oral hairy leukoplakia. A novel hypothesis is proposed for nasopharyngeal carcinoma in which BHRF1 expression protects cells against apoptotic death caused by environmental DNA damaging agents and thus contributes to the early stages of cancer development.

Retinoblastoma with micrometastasis to CSF

A 28 mth old male presented with a squint and leukocoria. Clinical examination and computerized tomography (CT) suggested a unilateral retinoblastoma with distal optic nerve involvement. Investigations for distant metastasis including lumbar puncture cytology were negative. The eye was enucleated and 12 mm of optic nerve was excised via a combined neurosurgical/ophthalmological approach. Histopathological examination confirmed the optic nerve to the point of excision was free of tumor. However, cytology of cerebrospinal fluid (CSF) from the Sylvian fissure, taken at the time of surgery, revealed malignant retinoblastoma cells. The patient was treated with intrathecal and intravenous chemotherapy, and cranial radiotherapy. He is alive and well 4 yrs later. This case displays the importance of CSF cytology from the Sylvian fissure, as it dramatically changed the management and prognosis for the child. The role of lumbar puncture cytology in excluding CSF micrometastasis can be unreliable. A neurosurgical approach to the optic nerve has the potential to gain access to a long length of optic nerve, should it be involved with tumor, and also allows direct CSF sampling.

Blink rate as an index of dopamine function in adults with mental retardation and repetitive behavior disorders

Direct observation of blink rate was used as a noninvasive, in vivo estimate of dopamine function in adults with mental retardation and repetitive behavior disorders. Blink rate as measured in groups of stereotypy, compulsion, and control subjects was highly stable. Subjects with stereotypies had significantly lower blink rates than did control subjects. Although blink rates for compulsive subjects were not significantly different from those of control subjects, a subgroup of compulsive subjects with comorbid stereotypic behaviors displayed significantly lower blink rates. Significant inverse correlations were found for blink rate and severity of repetitive behavior disorder and for blink rate and ratings of motor slowness. These findings support the hypothesis that stereotyped behavior among adults with mental retardation is mediated by hypodopaminergic function.

Comparison of invasive and non-invasive measurement of continuous arterial pressure using the Finapres in patients undergoing spinal anaesthesia for lower segment caesarean section

We have compared arterial pressures measured by an indwelling radial cannula with those obtained non-invasively by the Finapres 2000 (Ohmeda) during spinal anaesthesia for lower segment Caesarean section. The digital outputs of both pressures were recorded using a computerized system. We studied 20 patients, yielding a total of 18,772 data points after elimination of data recorded during arterial flushing and erroneous results from each source. The data analysis demonstrated a normal distribution for differences between the two methods of measurement, and the correlations between invasive and Finapres readings for systolic, diastolic and mean pressures were 0.78, 0.72 and 0.79, respectively, indicating an overall poor reflection of intra-arterial pressure by the Finapres under these circumstances. Some patients and some periods of readings reflected a high degree of precision and little bias. However, unexplained large differences in pressure and trends of change that were out of phase over time occurred frequently. We conclude that the Finapres cannot be recommended as a monitor of arterial pressure in this group of patients in whom sudden hypotension may be a threat to maternal or fetal outcome.

Spinal anaesthesia for caesarean section: comparison of infusions of phenylephrine and ephedrine

Maternal cardiovascular changes and neonatal acid-base status were assessed in 29 healthy women undergoing elective lower segment Caesarean section under spinal anaesthesia. The patients were allocated randomly to one of three groups to receive an i.v. infusion of one of the following: ephedrine 1 mg min-1 (group E1: n = 10), ephedrine 2 mg min-1 (group E2: n = 9), or phenylephrine 10 micrograms min-1 (group P: n = 10). Invasive arterial pressure was monitored continuously and if hypotension occurred (defined as a 20% decrease from baseline, taken after i.v. preload administration), bolus doses of either ephedrine (6 mg in groups E1 and E2) or phenylephrine (20 micrograms in group P) were given. Only four patients became hypotensive in group E2, compared with eight patients in group E1 and nine patients in group P. The total time that the patients remained hypotensive was greatest in group P (P < 0.005), less in group E1 and least in group E2. Neonatal Apgar scores and acid-base profiles were similar in all three groups. In this study, an infusion of phenylephrine 10 micrograms min-1 with bolus doses of 20 micrograms was shown to be significantly less effective in maintaining systolic arterial pressure within 20% limits of baseline compared with an infusion of ephedrine 1 or 2 mg min-1 with bolus doses of 6 mg.

Developmental change in infant cortisol and behavioral response to inoculation

Infant cortisol and behavioral responses to receiving 1 versus 2 inoculations on 1 pediatric office visit were observed at 2 and 6 months of age. Cortisol level (pre- plus postinoculation level) decreased with age, whereas cortisol response (post- minus preinoculation level) did not vary with age when the data were aggregated over infants showing a pre- to postinoculation cortisol increase and those showing a decrease. Nonetheless, for those infants who showed a cortisol increase, cortisol level and response decreased with age. Infants quieted faster at the older age. There was a moderate relation between quieting behavior and cortisol response, at least for infants who showed a pre- to postinoculation cortisol increase. These findings indicate a developmental trend for a decline over age in adrenocortical reactivity to inoculation for infants showing a cortisol release following the perturbation. Results were comparable whether infants received 1 or 2 inoculations.

Safety of the new quinolones in pregnancy

OBJECTIVE

To investigate the effect on the fetus of intrauterine exposure to quinolones in terms of teratogenicity, with special focus on the musculoskeletal system.

METHODS

We studied 38 pregnant women who received quinolones and consulted the Motherisk Program in Toronto from 1989-1992. Perinatal complications, birth weight, birth defects, and developmental milestones, with particular emphasis on the musculoskeletal system, were compared with those of controls matched for both maternal age and indication for antibacterial therapy.

RESULTS

Thirty-five women (92%) treated with norfloxacin or ciprofloxacin received therapy during the first trimester. The most common indication for therapy (92%) was urinary tract infection. More pregnancies in the quinolone group resulted in cesarean delivery due to reported fetal distress as compared to the controls (P = .005), without clear reason. Children born to mothers treated with quinolones were significantly heavier (P = .05) than the control infants, possibly because of better control of the urinary tract infection. No malformations were found in the quinolone group, whereas one child in the control group had a ventricular septal defect. No differences were detected between the groups in achievement of developmental milestones or in the musculoskeletal system.

CONCLUSION

The use of the new quinolones during the first trimester of pregnancy does not appear to be associated with an increased risk of malformations or musculoskeletal problems; however, longer follow-up and magnetic resonance imaging of the joints may be warranted to exclude subtle cartilage and bone damage.

Amniotic fluid erythropoietin levels in normal and Down's syndrome pregnancies

The aim of this study was to measure the levels of erythropoietin in amniotic fluid from normal and trisomy 21 pregnancies at 10 to 20 weeks gestation. Samples of amniotic fluid were collected from 142 women with singleton pregnancies after genetic amniocentesis; 110 had a normal fetal karyotype and 32 had trisomy 21. Erythropoietin was measured using a double antibody radioimmunoassay. Amniotic fluid erythropoietin levels in normal pregnancies increased from 10 weeks (mean 3.2 mU/ml; range < 2.0-6.3 mU/ml) to 20 weeks gestation (mean 7.9 mU/ml; range 2.0-11.5 mU/ml). There was a significant linear correlation between gestational age and erythropoietin levels (r = 0.543; P < 0.0001). For the 32 patients with trisomy 21 pregnancies the median multiple of the median (MoM) was 1.11 (range 0.42-2.1). There was no difference between erythropoietin levels in amniotic fluid from normal and Down's syndrome pregnancies (U = 2352, P = 0.75, 95% CI = -0.11, 0.18); (Mann-Whitney U-test).

What is the best way to determine oropharyngeal classification and mandibular space length to predict difficult laryngoscopy?

BACKGROUND

Previous studies have suggested that the degree of visibility of oropharyngeal structures (OP class) and mandibular space (MS) length can predict difficult laryngoscopy. However, those studies were either inconsistent or omit description of how to perform these tests with regard to body, head and tongue position, and the use of phonation, hyoid versus thyroid cartilage and inside versus outside of the mentum. The purpose of this investigation was to determine which method of testing best predicts difficult laryngoscopy.

METHODS

In each of 213 consenting adults the OP class was determined in 24 method combinations: two body positions (sitting and supine), three head positions (neutral, sniff, and full extension), two tongue positions (in and out), and with and without phonation. In each patient MS length was measured in 24 method combinations: two body positions (sitting and supine), three head positions (neutral, sniff, and full extension), two distal end points (hyoid and thyroid cartilage), and two proximal end points (inside and outside of the mentum). In each patient the laryngoscopic grade was determined at the time of induction of anesthesia. We defined laryngoscopic grades III (n = 24) and 4 (n = 0) as difficult. The area under the receiver operating characteristic curve (ROC area) for each combination was used to compare the combinations and determine significant differences: ROC area = 0.5 implied a totally uninformative combination and ROC area = 1.0 a combination that predicted perfectly. Logistic regression analysis was used to calculate a predictor of difficult intubation that combined both OP class and MS length (the performance index). The performance index could then be used to calculate sensitivity, specificity, positive and negative predictive value, and probability of difficult intubation.

RESULTS

The ROC areas for the different combinations used to assess OP class ranged from 0.78 to 0.94. The best combination was with the patient sitting, head in extension, tongue out, and with or without phonation. For MS length, the ROC areas ranged from 0.58 to 0.77; the best combination was the patient sitting, with the head in extension, with distance measured from the inside of the mentum to the thyroid cartilage. Combining the OP class and MS length (performance index = 2.5 X OP class - MS length in centimeters) significantly increased predictability of difficult intubation. At performance index = 0 and = 2, the probability of difficult intubation was 3.5% and 24%, respectively. With clinically relevant cutpoints for the performance index it was found that most difficult intubations could be predicted, but approximately half of those predicted to be difficult would in fact be easy.

CONCLUSIONS

Based on the above ROC areas and ease of performing the test for the patient, we recommend that these tests be performed with patients in the sitting position, with the head in full extension, the tongue out, and with phonation, and with distance measured from the thyroid cartilage to inside of the mentum. Nevertheless, it is clear that these two tests, either used alone or in combination, will fail to predict a few difficult laryngoscopies and that they will predict difficult laryngoscopy in a significant number of patients in whom the trachea is easy to intubate.

Weekly variation of acute myocardial infarction. Increased Monday risk in the working population

BACKGROUND

Seasonal and circadian variations in the occurrence of myocardial infarction and sudden cardiac death have been documented, suggesting that triggering factors may play a role in the causation of cardiac events. However, there are only sparse and conflicting data on the weekly distribution of the disorders.

METHODS AND RESULTS

To determine the weekly variation of acute myocardial infarction and sudden cardiac death, 5596 consecutive patients (71% men; age, 63 +/- 1 years) were analyzed in a regionally defined population (n = 330,000; age, 25 to 74 years) monitored from 1985 to 1990. The exact time of onset of symptoms was used to determine the day of the event. Patients with myocardial infarction (n = 2636) demonstrated a significant weekly variation (P < .01) with a peak on Monday, whereas patients with sudden cardiac death (n = 2960) were evenly distributed throughout the week. A similar weekly pattern was observed in subgroups of patients with myocardial infarction defined with respect to age, sex, cardiac risk factors, prior cardiac medication, and infarct characteristics. The working population demonstrated a weekly variation of myocardial infarction as opposed to the nonworking population, with a 33% increase in relative risk of disease onset on Monday (P < .05) and a trough on Sunday compared with the expected number of cases, if homogeneity was assumed.

CONCLUSIONS

The onset of acute myocardial infarction demonstrates a peak on Monday primarily in the working population. If this finding is confirmed in other communities, it may aid in identifying acute triggering events of myocardial infarction and perhaps in improving prevention of the disease.

[Stress factors in acute myocardial infarct: the role of physical exertion and unusual life events]

OBJECTIVE

It is controversial whether the onset of myocardial infarction is a "random" event or whether there are triggering factors of the disease. Previous reports on possible triggers were based on case studies or inadequately controlled studies. The TRIMM study (Triggers and Mechanisms of Myocardial Infarction) was designed to determine the influence of physical activity and other external factors on the acute risk of myocardial infarction.

METHODS

At Klinikum Steglitz, Berlin, all consecutive patients with myocardial infarction were included. In the Augsburg area, all patients with myocardial infarction in a prospectively defined cohort (n = 330,000) were registered by monitoring 26 hospitals. Information on the circumstances and possible triggers of the disease was obtained by standardized interviews. The control group was matched for age, sex, precinct, and time of a control event. The statistical analysis included a case-control comparison of patients with control subjects and a case-crossover comparison comparing the average exposure to a possible trigger with the time of the last exposure prior to the onset of disease.

RESULTS

From January 1989 to December 1991, 1194 patients (74% men, 61 +/- 9 years) were enrolled 13 +/- 6 days after myocardial infarction. During the initial three hours after awakening, the occurrence of myocardial infarction was almost threefold compared to other times of day. A multivariate analysis yielded a twofold risk of myocardial infarction during physical exertion, statistically independently of time of day. 7.1% of patients had engaged in exertional physical activity at onset of the event, as opposed to 3.9% of control subjects. The case-crossover analysis demonstrated a relative risk of 2.1 (1.6-3.1) of exertional physical activity within 1 hour prior to myocardial infarction. Patients whose average frequency of physical exertion was < 4 versus > or = to 4 times per week had relative risks of 6.9 versus 1.3 (p < 0.01). Unusual life events within 24 hours and 24 hours to 4 weeks prior to the event occurred with similar frequencies and control subjects.

CONCLUSIONS

Physical exertion appears to increase the acute risk of myocardial infarction in patients with coronary heart disease, particularly in untrained individuals. Unusual life events, however, are of less importance for the acute risk of disease. These findings are important for further investigation of triggering mechanisms of myocardial infarction and for improving preventive strategies.

A survey to determine the prevalence of leprosy in a community in east Trinidad

A house-to-house survey was conducted in a community in East Trinidad, where a clustering of cases had been observed. There were 1355 residents, of whom 73.5% had a complete visual skin examination. No new cases of leprosy were found but a variety of skin disorders were diagnosed. The most common disorder was pityriasis versicolor, which is one of the differential diagnoses of hypopigmented skin lesions. This has serious implications for the delayed diagnosis of leprosy. In all, 5 of the 9 old cases residing in the survey area suffered from paucibacillary disease, and had a history of contact with a lepromatous case. They were not listed initially as contacts of this index case. Contact lists should therefore include nonfamilial persons having frequent contact with an index case. The definition of 'frequent' should be determined by each programme. It may also be necessary to review the duration of surveillance of contacts. The survey was estimated to have cost about US $2,500 and was not considered to be cost-effective.

Association of genetic differences in social behavior and cellular immune responsiveness: effects of social experience

We have recently demonstrated that selective breeding of ICR mice for differences in social behavior (i.e., high versus low levels of social isolation-induced aggression) are related to increased susceptibility to tumor development and reduced levels of natural killer (NK) cell activity. In the present investigation, we sought to extend examination of the line differences in immune status to T and B cell responsiveness. In addition, we also sought to determine if social experience contributes to line differences in immune responsiveness. A cosibial design was used to examine whether single vs group housing modified the magnitude of line differences in immune status. Compared to aggressive (NC900) mice, nonaggressive (NC100) mice had significantly lower T cell proliferative responses to concanavalin A, lower IL-2 and gamma-interferon production, as well as significantly lower NK activity. Of the various measures of cellular immune responsiveness, housing condition was found to have a significant effect only on NK activity. No significant line by housing interactions were found for any of the immune measures tested. The present data demonstrate that the genetic selection for differences in social behavior is associated with line differences in several parameters of cellular immune responsiveness. These mouse lines provide a valuable research model to examine the association between selection for genetic differences in social behavior and differences in immune responsiveness.

Social reactivity and D1 dopamine receptors: studies in mice selectively bred for high and low levels of aggression

Robust individual differences in social behavior have been obtained by selectively breeding Institute for Cancer Research mice for high and low levels of aggression. As previously shown, when paired with a non-selected group-housed partner mouse, NC900 mice exhibit isolation-induced aggression. Conversely, NC100 mice fail to attack, freezing upon social contact. Previous studies have established that NC100 mice have lower dopamine concentrations in nucleus accumbens and caudate nucleus, with increased dopamine receptor densities in these same regions. Thus, we wished to determine the effect of administration of a dopamine receptor agonist on social behavior. Mice of both lines were administered 0, 1, 3, or 10 mg/kg (SC) of the full efficacy D1 receptor agonist dihydrexidine, and their behavior was assessed in a social interaction test. Dihydrexidine reduced aggression in NC900 mice and nonagonistic approach in NC100 mice in a dose dependent manner. In both cases, this resulted from induction of a marked reactivity to mild social stimulation as measured by increases in behaviors such as escape, reflexive kicking, and vocalizations. Dihydrexidine had no systematic effect on the freezing behavior characteristic of the low-aggressive line. In independent experiments, mice were pretreated with either the D1 antagonist SCH-23390 (.1 mg/kg) or the selective D2 antagonist remoxipride (1.0 mg/kg), after which they received dihydrexidine (10 mg/kg) and were tested as above. The effects of dihydrexidine on social reactivity in mice of both lines were significantly antagonized by SCH-23390 but not attenuated by remoxipride.(ABSTRACT TRUNCATED AT 250 WORDS)

An 11-year experience of arterial embolectomy in a district general hospital

We present a retrospective audit of all arterial embolectomies performed at the East Glamorgan General Hospital over an 11-year period (1980-1990). Eighty-seven patients (47M:40F), mean age 67 years (50-90 years) underwent 95 embolectomies, an incidence consistent with previous studies. There were 17 upper and 71 lower limb emboli with a mean delay before diagnosis of 29 h (range 1-264 h). In 66% of cases the cause was atrial fibrillation; 33% received immediate heparinization and 14% prophylactic antibiotics. Surgery was performed by a consultant in 12 and registrars in 75 cases, and under local anaesthesia in 80% and general anaesthesia in 20%. There was no anaesthetist present in 54% of cases. Few pre- or peroperative arteriograms were performed. The 30-day mortality was 45%, with an amputation rate of 15% and an overall postoperative complication rate of 62% with little improvement in these figures over the last 10 years. Factors increasing mortality were: delay before diagnosis, grade of surgeon performing the operation, and inadequate inflow or outflow at operation. Factors found to affect limb salvage rate adversely were a history of intermittent claudication, although such a history was not recorded in many cases, and lack of immediate preoperative heparinization. Although embolectomy is considered a 'registrar operation', reviewing our results it can be seen that it is an uncommon operation, in our series eight or nine being performed annually. Sometimes inappropriate surgery is performed upon patients in whom severe systemic illness may contraindicate any form of surgical intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional structure of rat liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase: a member of the aldo-keto reductase superfamily

The 3.0-A-resolution x-ray structure of rat liver 3 alpha-hydroxysteroid dehydrogenase/dihydrodiol dehydrogenase (3 alpha-HSD, EC 1.1.1.50) was determined by molecular replacement using human placental aldose reductase as the search model. The protein folds into an alpha/beta or triose-phosphate isomerase barrel and lacks a canonical Rossmann fold for binding pyridine nucleotide. The structure contains a concentration of hydrophobic amino acids that lie in a cavity near the top of the barrel and that are presumed to be involved in binding hydrophobic substrates (steroids, prostaglandins, and polycyclic aromatic hydrocarbons) and inhibitors (nonsteroidal antiinflammatory drugs). At the distal end of this cavity lie three residues in close proximity that have been implicated in catalysis by site-directed mutagenesis--Tyr-55, Asp-50, and Lys-84. Tyr-55 is postulated to act as the general acid. 3 alpha-HSD shares significant sequence identity with other HSDs that belong to the aldo-keto reductase superfamily and these may show similar architecture. Other members of this family include prostaglandin F synthase and rho-crystallin. By contrast, 3 alpha-HSD shares no sequence identity with HSDs that are members of the short-chain alcohol dehydrogenase family but does contain the Tyr-Xaa-Xaa-Xaa-Lys consensus sequence implicated in catalysis in this family. In the 3 alpha-HSD structure these residues are on the periphery of the barrel and are unlikely to participate in catalysis.