Strongyle infections in ponies. II. Reinfection of treated animals.
Five of seven ponies whose strongyle worm burdens had previously been removed or markedly reduced by repeated thiabendazole treatments were reinfected with doses ranging from 100,000 to 500,000 small strongyle infective larvae. Reinfection of ponies resulted in the development of clinical signs characterized by abnormal feces, marked loss of weight and delayed shedding of winter hair coats. An abrupt increase in circulating eosinophils occurred during the first three weeks following reinfection. Patent infections developed in all ponies with worm eggs appearing in the feces from 12 to 15 weeks after receiving infective larvae. Worm egg outputs followed a cyclic pattern with approximately four to five peaks in egg output per year. There was an abrupt drop in the high worm egg counts in two untreated ponies approximately two and a half years after reinfection. No worms were recovered in the feces of these animals when they were subsequently treated, suggesting that a depletion in the number of inhibited larvae present in these ponies might have occurred. (+info)
Comparative molecular genetic profiles of anaplastic astrocytomas/glioblastomas multiforme and their subsequent recurrences.
Malignant glial tumors (anaplastic astrocytomas and glioblastomas multiforme) arise mostly either from the progression of low grade precursor lesions or rapidly in a de novo fashion and contain distinct genetic alterations. There is, however, a third subset of malignant gliomas in which genetic lesions remain to be identified. Following surgical resection, all gliomas appear to have an inherent tendency to recur. Comparative molecular analysis of ten primary malignant gliomas (three anaplastic astrocytomas and seven glioblastomas multiforme) with their recurrences identified two distinct subgroups of recurrent tumors. In one group, primary tumors harbored genetic aberrations frequently associated with linear progression or de novo formation pathways of glial tumorigenesis and maintained their genetic profiles upon recurrence. In the other subset with no detectable known genetic mutations at first presentation, the recurrent tumors sustained specific abnormalities associated with pathways of linear progression or de novo formation. These included loss of genes on chromosomes 17 and 10, mutations in the p53 gene, homozygous deletion of the DMBTA1 and p16 and/ or p15 genes and amplification and/or overexpression of CDK4 and alpha form of the PDGF receptor. Recurrent tumors from both groups also displayed an abnormal expression profile of the metalloproteinase, gel A, and its inhibitor, TIMP-2, consistent with their highly invasive behavior. Delineation of the molecular differences between malignant glioblastomas and their subsequent recurrences may have important implications for the development of rational clinical approaches for this neoplasm that remains refractory to existing therapeutic modalities. (+info)
Paediatric, invasive pneumococcal disease in Switzerland, 1985-1994. Swiss Pneumococcal Study Group.
BACKGROUND: Cost effective use of new vaccines against pneumococcal disease in children requires detailed information about the local epidemiology of pneumococcal infections. METHODS: Data on 393 culture-confirmed cases of invasive pneumococcal infection in children (<17 years) hospitalized in Swiss paediatric clinics were collected retrospectively for the years 1985-1994. RESULTS: Meningitis (42%) was most frequent, followed by pneumonia (28%) and bacteraemia (26%). The overall annual incidence was 2.7 cases per 100000 children <17 years old and 11 cases per 100000 children <2 years old. Annual incidence rates were stable over the study period. Lethality was high for meningitis (8.6%) and bacteraemia (8.9%). A history of basal skull fracture was reported in 3.3% of children with pneumococcal meningitis. Residence in a rural region was associated with an increased risk of pneumococcal infection (relative risk = 1.45, 95% confidence interval: 1.01-2.00). CONCLUSIONS: Paediatric, invasive pneumococcal disease seems to be less frequent in Switzerland than in other European and non-European countries. This may be due to differences in diagnostic strategies and lower frequency of risk factors such as the use of day care. Children with a history of basal skull fracture are at increased risk for pneumococcal meningitis. Further investigation of the association of invasive pneumococcal infection with rural residence and the use of antibiotics for upper respiratory tract infections might give new insight into the dynamics of Streptococcus pneumoniae infection and the development of antibiotic resistance. (+info)
Longitudinal evaluation of serovar-specific immunity to Neisseria gonorrhoeae.
The serovars of Neisseria gonorrhoeae that are predominant in a community change over time, a phenomenon that may be due to the development of immunity to repeat infection with the same serovar. This study evaluated the epidemiologic evidence for serovar-specific immunity to N. gonorrhoeae. During a 17-month period in 1992-1994, all clients of a sexually transmitted disease clinic in rural North Carolina underwent genital culture for N. gonorrhoeae. Gonococcal isolates were serotyped according to standard methods. Odds ratios for repeat infection with the same serovar versus any different serovar were calculated on the basis of the distribution of serovars in the community at the time of reinfection. Of 2,838 patients, 608 (21.4%; 427 males and 181 females) were found to be infected with N. gonorrhoeae at the initial visit. Ninety patients (14.8% of the 608) had a total of 112 repeat gonococcal infections. Repeat infection with the same serovar occurred slightly more often than would be expected based on the serovars prevalent in the community at the time of reinfection, though the result was marginally nonsignificant (odds ratio = 1.5, 95% confidence interval 1.0-2.4; p = 0.05). Choosing partners within a sexual network may increase the likelihood of repeat exposure to the same serovar of N. gonorrhoeae. Gonococcal infection did not induce evident immunity to reinfection with the same serovar. (+info)
Validation of the Rockall risk scoring system in upper gastrointestinal bleeding.
BACKGROUND: Several scoring systems have been developed to predict the risk of rebleeding or death in patients with upper gastrointestinal bleeding (UGIB). These risk scoring systems have not been validated in a new patient population outside the clinical context of the original study. AIMS: To assess internal and external validity of a simple risk scoring system recently developed by Rockall and coworkers. METHODS: Calibration and discrimination were assessed as measures of validity of the scoring system. Internal validity was assessed using an independent, but similar patient sample studied by Rockall and coworkers, after developing the scoring system (Rockall's validation sample). External validity was assessed using patients admitted to several hospitals in Amsterdam (Vreeburg's validation sample). Calibration was evaluated by a chi2 goodness of fit test, and discrimination was evaluated by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Calibration indicated a poor fit in both validation samples for the prediction of rebleeding (p<0.0001, Vreeburg; p=0.007, Rockall), but a better fit for the prediction of mortality in both validation samples (p=0.2, Vreeburg; p=0.3, Rockall). The areas under the ROC curves were rather low in both validation samples for the prediction of rebleeding (0.61, Vreeburg; 0.70, Rockall), but higher for the prediction of mortality (0.73, Vreeburg; 0.81, Rockall). CONCLUSIONS: The risk scoring system developed by Rockall and coworkers is a clinically useful scoring system for stratifying patients with acute UGIB into high and low risk categories for mortality. For the prediction of rebleeding, however, the performance of this scoring system was unsatisfactory. (+info)
Transcatheter closure of patent foramen ovale using the Amplatzer septal occluder to prevent recurrence of neurological decompression illness in divers.
OBJECTIVE: Large flap valve patent foramens may cause paradoxical thromboembolism and neurological decompression illness in divers. The ability of a self expanding Nitinol wire mesh device (Amplatzer septal occluder) to produce complete closure of the patent foramen ovale was assessed. PATIENTS: Seven adults, aged 18-60 years, who had experienced neurological decompression illness related to diving. Six appeared to have a normal atrial septum on transthoracic echocardiography, while one was found to have an aneurysm of the interatrial septum. METHODS: Right atrial angiography was performed to delineate the morphology of the right to left shunt. The defects were sized bidirectionally with a precalibrated balloon filled with dilute contrast. The largest balloon diameter that could be repeatedly passed across the septum was used to select the occlusion device diameter. Devices were introduced through 7 F long sheaths. All patients underwent transthoracic contrast echocardiography one month after the implant. RESULTS: Device placement was successful in all patients. Device sizes ranged from 9-14 mm. The patient with an aneurysm of the interatrial septum had three defects, which were closed with two devices. Right atrial angiography showed complete immediate closure in all patients. Median (range) fluoroscopy time was 13.7 (6-35) minutes. Follow up contrast echocardiography showed no right to left shunting in six of seven patients and the passage of a few bubbles in one patient. All patients have been allowed to return to diving. CONCLUSION: The Amplatzer septal occluder can close the large flap valve patent foramen ovale in divers who have experienced neurological decompression illness. Interatrial septal aneurysms with multiple defects may require more than one device. (+info)
Outcome of pregnancy in women with congenital shunt lesions.
OBJECTIVE: To evaluate the outcome of pregnancy in women with congenital shunt lesions. SETTING: Retrospective study in a tertiary care centre. METHODS: Pregnancy history was obtained by a standardised questionnaire and medical records were reviewed. PATIENTS: 175 women were identified, at a mean (SD) age of 42 (14) years. Pregnancies occurred in 126 women: 50 with an atrial septal defect, 22 with a ventricular septal defect, 22 with an atrioventricular septal defect, 19 with tetralogy of Fallot, and 13 with other complex shunt lesions. RESULTS: 309 pregnancies were reported by 126 woman (2.5 (1.6) pregnancies per woman). The shortening fraction of the systemic ventricle was 40 (8)%, and 98% were in New York Heart Association class I-II at last follow up. Spontaneous abortions occurred in 17% of pregnancies (abortion rate, 0.4 (0.9) per woman). Gestational age of the 241 newborn infants was 8.8 (0.8) months. There were no maternal deaths related to pregnancy. Pre-eclampsia and embolic events were observed in 1.3% and 0.6%, respectively of all pregnancies. Women with complex shunt lesions more often underwent caesarean section (70% v 15-30%, p = 0.005) and gave birth to smaller babies for equivalent gestation (2577 (671) g v 3016 (572) to 3207 (610) g, p < 0.05). The recurrence risk of congenital heart disease was 2.5%. CONCLUSIONS: The outcome of pregnancy is favourable in women with congenital shunt lesions if their functional class and their systolic ventricular function are good. Such patients can be reassured. (+info)
Recurring myocardial infarction in a 35 year old woman.
A 35 year old woman presented with acute myocardial infarction without any of the usual risk factors: she had never smoked; she had normal blood pressure; she did not have diabetes; plasma concentrations of total cholesterol and high and low density lipoprotein cholesterol, fibrinogen, homocysteine, and Lp(a) lipoprotein were normal. She was not taking oral contraceptives or any other medication. Coronary angiography showed occlusion of the left anterior descending coronary artery but no evidence of arteriosclerosis. Medical history disclosed a previous leg vein thrombosis with pulmonary embolism. Coagulation analysis revealed protein C deficiency. The recognition of protein C deficiency as a risk factor for myocardial infarction is important as anticoagulation prevents further thrombotic events, whereas inhibitors of platelet aggregation are ineffective. (+info)