Horizontal transmission of Escherichia coli O157:H7 during cattle housing

Ruminant livestock, particularly cattle, is considered the primary reservoir of Escherichia coli O157:H7. This study examines the transmission of E. coli O157:H7 within groups of cattle during winter housing. Holstein Friesian steers were grouped in six pens of five animals. An animal inoculated with and proven to be shedding a marked strain of E. coli O157: H7 was introduced into each pen. Fecal (rectal swabs) and hide samples (900 cm2 from the right rump) were taken from the 36 animals throughout the study. Water, feed, and gate or partition samples from each pen were also examined. Within 24 h of introducing the inoculated animals into the pens, samples collected from the drinking water, pen barriers, and animal hides were positive for the pathogen. Within 48 h, the hides of 20 (66%) of 30 cohort animals from the six pens were contaminated with E. coli O157:H7. The first positive fecal samples from the noninoculated cohort animals were detected 3 days after the introduction of the inoculated steers. During the 23 days of the study, 15 of 30 cohort animals shed the marked E. coli O157:H7 strain in their feces on at least one occasion. Animal behavior in the pens was monitored during a 12-h period using closed circuit television cameras. The camera footage showed an average of 13 instances of animal grooming in each pen per hour. The study suggests that transmission of E. coli O157:H7 between animals may occur following ingestion of the pathogen at low levels and that animal hide may be an important source of transmission.

Cervical and vaginal epithelial neoplasms in cynomolgus monkeys

Papillomavirus-associated cervical cancer is the second most common neoplasm in women but has rarely been reported in animals. This report describes cervical and vaginal intraepithelial neoplasms identified in routine histologic specimens obtained from 20 (5.2%) of 385 female cynomolgus macaques (Macaca fascicularis) being used in long-term studies. Lesion incidence was similar in both control and hormonally treated animals (4.7% and 5.5%, respectively). Neoplasms included benign vaginal papillomas, mild to severe intraepithelial dysplasias, and two invasive cervical carcinomas. Common morphologic features included koilocytosis, nuclear atypia, and expansion of the basal epithelium. Selective staining of lesions with at least one of three papillomavirus antibodies was observed in all cases (20 of 20). In contrast, immunostaining of lesions was negative for Epstein-Barr-related virus proteins (0 of 20). The unique similarities between the observed lesions and those seen in women suggest that macaques may provide a suitable animal model for study of papillomavirus oncogenesis.

Teaching PRHO prescribing

Changes have occurred recently in the teaching syllabus in medical schools across the United Kingdom. These changes have taken the format of modular teaching with group participation and the grouping of topics such as anatomy, physiology and clinical medicine being combined. A short study was designed to assess if students of the new curriculum were competent at answering clinical questions that occur frequently, and common prescribing requests.

Does egg-sharing compromise the chance of donors or recipients achieving a live birth?

BACKGROUND

To evaluate the effect of egg-sharing and the outcome of assisted reproductive treatment (ART) in standard IVF/ICSI patients, egg-sharing donors and egg-sharing recipients.

METHODS

Descriptive cohort study to evaluate 276 egg-sharing cycles involving 192 egg-sharers, 274 recipient cycles receiving eggs from egg-sharers and 1098 non-egg-sharing standard IVF/ICSI cycles from January 1998 to December 2002. Patients were divided into three groups: group A, egg-sharers; group B, non-egg-sharers, age <36 years, FSH <10 IU/l, BMI <30 kg/m(2); and group C, egg-sharing recipients, all ages. Duration and amount of gonadotrophin required to achieve follicular maturity, number of eggs collected and donated, fertilization rate, pregnancy rates and live birth rates were compared between donor, recipient and standard IVF/ICSI patients. The chi(2 )test was used to test for statistical significance (P < 0.05).

RESULTS

There was no significant difference in pregnancy rate and live birth rate of egg-sharers, group A (42.0%, 33.0%), non-egg-sharers, group B (40.0%, 30.9%) and recipients, group C (41.4%, 28.6%). The number of oocytes collected, number of mature follicles and amount of gonadotrophin used was not significantly different between the two groups (A and B). The average number of embryos transferred and the mean number of eggs allocated between egg-sharers and recipients was not statistically different.

CONCLUSION

Egg-sharing does not compromise the chance of achieving a pregnancy or live birth for the egg-sharer or the recipient as compared to standard IVF/ICSI patients. The egg-sharers were not at a higher potential risk of ovarian stimulation syndrome and there was no imbalance of egg allocation.

Liver-related biochemical changes in the serum of dogs being treated with phenobarbitone

The concentrations of phenobarbitone, albumin, bile acids and cholesterol, and the activities of alkaline phosphatase (AP), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT) and glutamate dehydrogenase (GLDH) were measured in the serum of 95 epileptic dogs whose clinical signs were controlled with phenobarbitone. The dogs were divided into groups on the basis of the concentration of phenobarbitone in their serum, the dose administered and the duration of the treatment. The concentration of phenobarbitone in serum was directly related to the activities of ALT, AP, GGT and GLDH and inversely related to the concentration of albumin. There was no significant relationship between the duration of treatment and the serum concentration of phenobarbitone, but there was a significant relationship between the duration of treatment and the activities of ALT, AP and GLDH. Thirty-five of the dogs (37 per cent) had serum activities of AP above the normal range, 19 had abnormally high activities of ALT, and 15 had high activities of GLDH, but these incidences were not related to the serum concentration of phenobarbitone. The dogs receiving higher doses for longer periods had the highest incidence of high activities of AP, ALT and GLDH. The concentration of bile acids in seven of the dogs was above the normal range but there was no relationship between the concentration and either the serum concentration, dose or duration of treatment with phenobarbitone.

Dissociation of augmented physiological, hormonal and cognitive responses to hypoglycaemia with sustained caffeine use

In patients with Type I diabetes and healthy volunteers, ingestion of modest amounts of caffeine augments the usual symptomatic and counter-regulatory responses to hypoglycaemia. The aim of the present study was to determine whether these are lost with sustained caffeine use, i.e. does tolerance develop? Eleven healthy caffeine consumers underwent two identical hyperinsulinaemic glucose clamp procedures. For 7 days prior to each clamp, subjects consumed a caffeine-free diet supplemented with 200 mg of caffeine capsules twice daily (caffeine-replete) or placebo (caffeine-withdrawn). During each clamp, blood glucose was held for 80 min at 4.5 mmol/l and then 2.5 mmol/l. At 85 min, subjects were given a 200 mg caffeine capsule. Measurements were taken of symptoms, plasma catecholamine, middle cerebral artery blood velocity (V(MCA)) and cognition. Following the acute caffeine challenge and during hypoglycaemia, V(MCA) fell only in the caffeine-withdrawn condition [-5.1 (-7.3, -3.0) cm/s compared with -1.9 (-4.0, +0.2) cm/s in caffeine-replete condition; P <0.04; values are differences (95% confidence intervals)]. Plasma catecholamine levels and global cognitive performance were unaffected by caffeine status, whereas tests of executive intellectual function were better preserved during hypoglycaemia in the caffeine-replete condition ( P <0.05). The influence of caffeine on hypoglycaemic symptomatic awareness depended upon the duration of the hypoglycaemic stimulus. At onset, symptoms were more intense in caffeine-withdrawn state ( P <0.01); however, with increasing duration of hypoglycaemia, symptom intensity was greater in caffeine-replete condition ( P <0.05). Thus previous caffeine consumption influences the physiological and symptomatic responses to acute hypoglycaemia, but complete tolerance does not develop with sustained use.

Tuberculosis in east timorese refugees: implications for health care needs in East Timor

SETTING

East Timorese refugees evacuated to Darwin, Australia, September 1999.

OBJECTIVE

Presentation of the process and results of tuberculosis (TB) screening in a previously unscreened refugee population.

DESIGN

Screening for TB by clinical examination (all persons) and chest X-ray (CXR) (persons over 12 years of age and those of any age with respiratory symptoms) and sputum microscopy and mycobacterial culture (abnormal CXR).

RESULTS

Seventy-six patients were diagnosed with TB (38 culture-positive for Mycobacterium tuberculosis, including 11 sputum smear-positive). Of 89 positive mycobacterial cultures, 51 were non-tuberculous mycobacteria (NTM). Of the M. tuberculosis isolates, 82.2% were fully sensitive, 17.2% were resistant to isoniazid and 8.6% were resistant to isoniazid and streptomycin. Fifty-three consecutively diagnosed patients with TB were HIV-negative. The TB burden in this population was very high (point prevalence of 542/100,000 for smear-positive and 2,060/100,000 for culture-positive cases). Rates of culture for NTM were also high. Information from this study assisted the implementation of a National TB Control Programme for East Timor in February 2000.

CONCLUSION

The challenges for public health authorities in East Timor to provide a successful TB control programme are enormous. The apparently low prevalence of drug resistance and HIV co-infection in the population is encouraging.

Evaluation of phenylpropanolamine in the treatment of urethral sphincter mechanism incompetence in the bitch

In a multicentre, blinded, placebo-controlled trial, 50 dogs were treated for 28 days with either phenylpropanolamine or a placebo control. Each was given at a dose of one drop per 2 kg orally three times daily, equivalent to 1 mg/kg three times daily of phenylpropanolamine. Dogs that presented with clinical signs consistent with urinary sphincter mechanism incontinence were included in the study. They were examined on three occasions by the investigating veterinary surgeon. The frequency and volume of unconscious urination were scored by veterinary surgeons according to a pre-established scoring system. Phenylpropanolamine proved to be more effective than the placebo in regard to several parameters. At day 28, 85.7 per cent of phenylpropanolamine-treated cases had no episodes of unconscious urination compared with 33.3 per cent of placebo-treated cases. This was statistically significant. Few, mild side effects were seen in either group.

Role of facilitative glucose uptake in the glucose-inorganic phosphate-mediated retardation and inhibition of development in different strains of mouse embryos

Mouse embryos from different strains develop differently in vitro depending on the composition of the culture medium, and in particular on the presence or absence of glucose and inorganic phosphate. Glucose is both stimulatory and inhibitory in certain conditions. Glucose uptake by cells can be passive, down concentration gradients, or active, through sodium driven pumps, or can occur through facilitative transport. This study investigated the effects of inhibition of facilitative glucose transport on the glucose-inorganic phosphate-mediated blocks in development in three different strains of mouse embryo, CF-1, CD-1 and an F2 hybrid. Development of CF-1 and CD-1 embryos is blocked in medium containing glucose and inorganic phosphate but not in medium containing glucose alone, and F2 embryos are not affected. Inhibition of facilitated glucose transport to the eight-cell-morula stage in CF-1 and CD-1 embryos resulted in development in medium containing both glucose and inorganic phosphate, indicating that the prevention of facilitative glucose uptake can overcome the developmental block. Removal of inhibition before the eight-cell-morula stage resulted in total arrest of CF-1 embryos and minimum development of CD-1 embryos. F2 embryos are not affected by inorganic phosphate and glucose and showed no response to the transporter inhibitor at any stage. These data support the contention that facilitated glucose transport is active in embryos, is phosphate-dependent and that its inhibition can overcome the glucose-inorganic phosphate-mediated developmental blocks in mouse embryos.

Survival to discharge following open chest cardiac compression (OCCC). A 4-year retrospective audit in a cardiothoracic specialist centre--Royal Brompton and Harefield NHS Trust, United Kingdom

OBJECTIVE

To review the use of Open Chest Cardiac Compression (OCCC) techniques in postcardiac surgical patients in one specialist cardiothoracic centre in the UK.

METHODS

A 4-year retrospective audit (April 1995--March 1999) of all cardiac arrest victims and resuscitation practice across two specialist cardiothoracic hospitals. Audit outcomes related to initial survival and survival to discharge, arrest rhythm, reasons for resternotomy, surgical procedure prior to resternotomy and time elapsed from original surgery to resternotomy.

RESULTS

Seventy-two patients (adult and paediatric) suffering cardiac arrest received OCCC following cardiac surgery. Thirty-three patients initially survived (46%) and 12 patients survived to discharge (17%).

DISCUSSION AND RECOMMENDATIONS

In the absence of current European Resuscitation Council guidelines, we adopted recommendations for resternotomy to be performed after 5 min of unsuccessful conventional CPR and OCCC initiated. An adapted ERC algorithm incorporating these recommendations can provide much needed direction in postcardiac surgery cardiac arrest victims.

Affordable CD4+ T cell counts by flow cytometry. II. The use of fixed whole blood in resource-poor settings

We tested the feasibility and precision of affordable CD4+ T cell counting in resource-poor settings using a recently standardised fixative, TransFix in whole blood (WB) by flow cytometry (FCM). The precision of the assays was established under optimal conditions for single-platform FCM such as the volumetric CytoronAbsolute and the bead-based FACSCan. Fresh WB samples from HIV-seropositive and seronegative patients were tested in Tanzania and South Africa, fixed and sent to the UK for reanalysis 7 days later. Correlation, bias and limits of agreements were analysed by linear regression and the Bland-Altman test. Absolute CD4+ T cell counts remained stable for at least 10 days when TransFix was added to WB in 1:10 dilution at 20-25 degrees C, and for 7 days when added in 1:10 or 1:5 dilution to samples stored to mimic 'tropical' conditions at 37 degrees C. Higher temperatures such as 42 degrees C were tolerated for only short periods since the recovery had decreased to 63% by day 3. The reproducibility of lymphocyte subset analysis remained unchanged by TransFix with coefficient of variations <6% for all T cell subsets. Absolute CD4+ T cell counts and CD4+ T cell % values on fixed samples in the UK showed a high correlation with the results using fresh samples in Tanzania (r=0.993 and 0.969, respectively) and with the samples handled in Johannesburg (r=0.991 and 0.981) with minimal bias. Primary CD4 gating using only a single CD4 antibody also remained accurate in TransFixed samples (r=0.999). Thus, TransFix permits optimal fixation and transport of WB samples in the developing world for FCM to local regional laboratories and for quality assurance in international centres. When used together with inexpensive primary CD4 gating, TransFix will allow reliable and affordable CD4+ T cell counting by FCM in resource-poor settings.

Electrocardiogram and rhythm strip interpretation by final year medical students

The pre-registration house officers (PRHO) is often called upon to interpret electrocardiograms ECG. We invited final-year medical students who had successfully completed their written final examinations, to interpret three rhythm-strip tracings, and three 12-lead ECG tracings. The rhythm-strips were of ventricular fibrillation (VF), ventricular tachycardia (VT), and complete heart block. Of the three 12-lead ECG tracings, one was an inferior myocardial infarction (MI), one was atrial fibrillation (AF), and one showed no abnormality. Forty-six medical students attended. Of these, 50% had received no formal training in ECG interpretation, although 89% had tried to learn ECG interpretation from books. Only 9% felt confident in their interpretation of ECG tracings. Of the rhythm-strips, 100% correctly identified VF, 96% recognised VT, and 67% identified complete heart block. Of the 12-lead ECG tracings, 61 % recognised the MI, 54% recognised AF, and only 46% successfully identified the normal ECG as such. The group were significantly worse at 12-lead ECG interpretation compared to rhythm-strips (p<0.01). The members of the group who had received formal training in ECG interpretation were significantly better at interpreting both rhythm-strips and 12-lead ECG tracings (p<0.05). It would appear that formal ECG training as an undergraduate improves PRHO interpretation of ECG tracings, and the PRHO should not interpret 12-lead ECG tracings without consulting more senior medical staff.

Technique of right laparoscopic donor nephrectomy: a single center experience

The majority of laparoscopic donor nephrectomies (LDNs) are limited to the left side due to technical and allograft concerns in using the right. We review our experience with right LDNs. Since June 1997, 15 right LDNs were performed and the records retrospectively reviewed for demographics, operative time, transfusions, complications, and length of stay. Recipient records were also reviewed for delayed graft function, complications, and serum creatinine levels. Overall donor, recipient and graft survivals at 6 months are 100%. Mean operative time was 317 +/- 11.0 min, length of stay was 4.2 +/- 0.2 d, and mean serum creatinine levels at discharge, 1, 3, and 6 months were 1.74 +/- 0.19, 1.59 +/- 0.13, 1.72 +/- 0.13, and 1.68 +/- 0.13 mg/dL, respectively. No transfusions were required. There were no operative or hospital complications. Two recipients (13.3%) experienced delayed graft function, defined as requiring hemodialysis post-transplantation. With hand-assisted laparoscopy, the right laparoscopic donor nephrectomy is safe and allows excellent allograft function.

An improved method for preparing thick sections for immuno/histochemistry and confocal microscopy and its use to identify rare events

Detection of rare events within solid tissues by immunocytochemistry is aided by imaging thick sections. Sections of 40--100 microm thickness of paraformaldehyde-fixed solid tissue can be prepared by use of a vibrating microtome and when immunolabelled these sections can be imaged in a confocal microscope. This approach provides excellent preservation of the structure of the sample and imposes minimal antigenic damage. In studies of the invasion of the bovine intestinal epithelium by Salmonella, this method has allowed detection of individual invading bacteria within large samples. The thick vibrating microtome sections were also used for the detection of rare apoptotic cell nuclei identified by TUNEL staining.

Home care: what a physician needs to know

When elderly patients might benefit from home care, a key question is whether Medicare will pay for it. We describe what physicians can do to avoid the pitfalls in qualifying appropriate patients for Medicare's Home Health Services and hospice programs, and the basic features of these two programs. We also describe the experience and methods used in prototype programs that provide home-based hospital-level care, and that revive a supposedly lost art: physician house calls.

Validation for MEDFICTS, a dietary assessment instrument for evaluating adherence to total and saturated fat recommendations of the National Cholesterol Education Program Step 1 and Step 2 diets

MEDFICTS is a dietary assessment instrument designed to evaluate patient adherence to the National Cholesterol Education Program Step 1 and Step 2 diets. It provides a quick way to record food intake, portion size, and frequency of intake while focusing on foods that are the primary contributors of total fat, saturated fat, and cholesterol in the average American diet (i.e., Meats, Eggs, Dairy, Fried foods, fat In baked goods, Convenience foods, fats added at the Table and Snacks). MEDFICTS was validated in a pilot study using 16 computer-analyzed sets of 4-day food records randomly selected from 7-day food records collected in the Diet Modification Clinic at Baylor College of Medicine, Houston, Tex). MEDFICTS correctly identified the 11 patients consuming a Step 1 diet, the 2 patients consuming the Step 2 diet and the 3 patients consuming an average American diet. Pearson correlation coefficients between MEDFICTS and the 4-day records were significant for percent energy from total fat (r = 0.81, P < .0002), saturated fat (r = 0.79, P < .0003), and cholesterol (r = 0.52, P < .039). Pearson correlation coefficients from 2 follow-up validation studies (3-day diet records [n = 22] through the Mary Imogene Bassett Research Institute, Cooperstown, NY, and a second study at the Diet Modification Clinic [n = 26]) also correlated significantly with percent energy from total fat (r = 0.56, P < .006; r = 0.71, P < .0001), saturated fat (r = 0.60, P < .003; r = 0.71, P < .0001), and approached significance for cholesterol intake (r = 0.54, P < .009; r = 0.39, P < .051) respectively. MEDFICTS is a quick, efficient tool that can be used in cardiovascular health screening, clinical practice, or research for the assessment of adherence to Step 1 or 2 diets. It can be self administered, and when reviewed with a dietitian, can provide an opportunity for nutrition education.

Isolation of markers from recently transposed LINE-1 retrotransposons

Many previous techniques for the isolation of endogenous retroelements such as LINE-1 retrotransposons have produced major sampling bias or required laborious procedures. These problems led to the isolation of only older elements in some cases. In other cases, specialized systems were required for the isolation of recently transposed elements. We report here a system for the easy isolation of markers from a wide range of LINE-1 elements and the screening of recently transposed elements from that population. This is accomplished by the use of PCR with degenerate primers specific for conserved regions of the reverse transcriptase gene, a modified screening vector, and a refined blue/white colony assay that screens for amplified DNA containing open reading frames. This method should be applicable to searches for endogenous retroviruses.

Using unaffected child trios to test for transmission distortion

The transmission disequilibrium test (TDT), an alternative to case-control analysis that is not influenced by population stratification, focuses on affected child trios (ACTs) comprising affected cases and their parents. Unaffected child trios (UCTs) have also been proposed but mainly to rule out segregation distortion. To explore situations when UCTs are preferable to detect transmission distortion, we compared the number of UCTs and ACTs needed to achieve 80% power for a wide variety of scenarios. For a given genetic model, UCT sample size declined rapidly with increasing disease prevalence, whereas ACT sample size remained constant. Furthermore, at some prevalence value (40-60% depending on model parameters), detection of transmission distortion could be accomplished with fewer UCTs than ACTs. Such high prevalence may be found in special populations (diabetes among Pima Indians), secondary conditions (renal/retinal complications in diabetes), and pharmacogenetics (responders to treatment). Also, because exposure to an additional risk factor can increase the disease prevalence in an exposed sub-group, we explored how sample size requirements vary by exposure status. Whereas power differences between exposed and unexposed ACTs could be explained solely by genetic risk ratios, sub-group-specific disease prevalence also played an important role in UCTs. Finally, we considered the impact of including 5, 10, 20, or 30% misclassified ACTs in the UCT sample and found that a 24, 58, 180, or 550% larger sample would be required. In conclusion, UCTs can detect transmission distortion more effectively than ACTs when disease prevalence reaches 40-60%, although some efficiency may be lost owing to misclassification. Moreover, focusing on particular sub-groups defined by exposure status can potentially increase power, but such gains depend heavily on the nature of the gene-exposure interaction.

The morphology of human pronuclear embryos is positively related to blastocyst development and implantation

Human embryos are selected for transfer using morphology at the cleaving and blastocyst stages. Zygote morphology has been related to implantation and pregnancy. The aim of this study was to relate pronuclear morphology to blastocyst development. Zygotes were scored according to distribution and size of nucleoli within each nucleus. Zygotes displaying equality between the nuclei had 49.5% blastocyst formation and those with unequal sizes, numbers or distribution of nucleoli had 28% blastocyst formation. Cleaving embryos that were selected initially by zygote morphology and secondarily by morphology on day 3 had increased implantation (IR) and pregnancy rates (PR; 31 and 57%), compared with those selected by morphology alone (19 and 33% respectively; P: < 0.01). There was a significant difference between zygote-scored and non-scored cycles on day 3 (PR: 57 versus 33%; IR: 31 versus 19%) and on day 5 (PR: 73 versus 58%; IR; 52 versus 39%). Zygote scoring can maintain pregnancy rates for both day 3 and day 5 transfers, increase implantation rates and reduce the numbers of embryos required to achieve a pregnancy.

Single amino acid (arginine) deprivation: rapid and selective death of cultured transformed and malignant cells

The effects of arginine deprivation (-Arg) has been examined in 26 cell lines. Less than 10% of those with transformed or malignant phenotype survived for > 5 days, and many died more rapidly, notably leukaemic cells. Bivariate flow cytometry confirmed that vulnerable cell lines failed to move out of cell cycle into a quiescent state (G0), but reinitiated DNA synthesis. Many cells remained in S-phase, and/or had difficulty progressing through to G2 and M. Two tumour lines proved relatively 'resistant', A549 and MCF7. Although considerable cell loss occurred initially, both lines showed a 'cell cycle freeze', in which cells survived for > 10 days. These cells recovered their proliferative activity in +Arg medium, but behaved in the same manner to a second -Arg episode as they did to the first episode. In contrast, normal cells entered G0 and survived in -Arg medium for several weeks, with the majority of cells recovering with predictable kinetics in +Arg medium. In general, cells from a wide range of tumours and established lines die quickly in vitro following -Arg treatment, because of defective cell cycle checkpoint stringency, the efficacy of the treatment being most clearly demonstrated in co-cultures in which only the normal cells survived. The findings demonstrate a potentially simple, effective and non-genotoxic strategy for the treatment of a wide range of cancers.