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Biomedical subjects

N McCarthy

Publications and source records attributed to N McCarthy.

At least 37 records · Page 2Linked to original sources

Epidemiological explanation of an outbreak of gastro-enteritis in Sweden in the absence of detailed microbiological information.

Waterborne gastroenteritis outbreaks have often gone undetected or been incompletely defined in terms of source and extent. Methods which allow detection or clarification of such events are therefore useful. We describe the methods used to detect and investigate such an outbreak. In autumn 1996 high school absence rates and the rate of parents absent from work to care for sick children suggested a health problem in a Swedish town which had a history of unexplained outbreaks of gastrointestinal disease. A systematic sample of 300 households was surveyed by post. Respondents represented 10% of the total population of the town. Questions concerning symptoms and exposures were included. The same questionnaire was used in a nearby town as a control. Sixty four percent of respondents reported an acute gastrointestinal illness during a two month period. Diarrhoea (90%) and abdominal pain (88%) were the most frequent symptoms among the sick. Two percent of those sick sought medical care. Exposures associated with disease were being a member of a large household, young age, and consumption of water from the community water supply. Attack rate showed a dose response relationship with increasing frequency of water consumption. The peak incidence of gastrointestinal illness occurred shortly after raw water quality control data had shown a rise in indicator bacteria. Further analysis, dividing those infected into groups according to when they became ill and whether they were the first member of their household to fall ill, supported the hypothesis of primary cases being infected from the water supply with some secondary person to person spread.

Disease Outbreaks↗

Biochemistry of cell death.

Apoptosis is a common feature of the nervous system, occurring physiologically during development and pathologically in several diseases. In view of the latter, pathways that regulate apoptosis in neurones are of particular interest, and recent advances in this field implicate several signalling pathways in the induction of apoptosis, after withdrawal of nerve growth factor. Recent information drawn from both mammalian and invertebrate models enables us to assign components of the apoptotic pathway as either regulators or effectors.

Animals↗

Antiepithelial cell antibodies do not impair paediatric renal allograft survival but appear to be associated with acute viral infections.

There is a reported association between antiepithelial cell (AEC) antibodies and increased renal allograft loss in paediatric recipients. Our unit experienced a dramatic fall in 1-year graft survival so we undertook a study to determine if AEC antibodies could account for such losses. We also studied healthy children and adults as well as a group of individuals with serologically proven viral infection in an attempt to determine the prevalence and possible aetiology of these antibodies. Sera were screened for AEC antibodies in a microcytotoxicity test using a lung epithelial cell line (A549) as target. The prevalence of these antibodies in our paediatric recipients was similar to that reported elsewhere but we found no correlation between the presence of AEC antibody and allograft loss. Within the control populations, we found the antibody was more prevalent in children than in adults (p < 0.0001). We also found a strong age banding pattern, with antibody being present in 50% of children under 10 years and declining with increasing age, so that by the age of 16 years the seroprevalence was similar to that found in our adults. However, AEC antibody had a significantly higher prevalence in individuals with active viral infection than in our healthy control groups (p = 0.00003). A positive association was noted between rubella and respiratory syncytial virus and AEC antibody presence and a negative association with varicella zoster. We conclude that AEC antibodies do not correlate with increased paediatric renal allograft loss but appear to be linked to certain viral infections.

Acute Disease↗

Damage to the superior gluteal nerve after the Hardinge approach to the hip.

We studied prospectively 81 consecutive patients undergoing hip surgery using the Hardinge (1982) approach. The abductor muscles of the hip in these patients were assessed electrophysiologically and clinically by the modified Trendelenburg test. Power was measured using a force plate. We performed assessment at two weeks, and at three and nine months after operation. At two weeks we found that 19 patients (23%) showed evidence of damage to the superior gluteal nerve. By three months, five of these had recovered. The nine patients with complete denervation at three months showed no signs of recovery when reassessed at nine months. Persistent damage to the nerve was associated with a positive Trendelenburg test.

Aged↗

Sixth nerve palsy: an unusual manifestation of preeclampsia.

BACKGROUND: Neurologic abnormalities may occur in pregnancy as a manifestation of neurologic or systemic disease. We present an unusual case of preeclampsia presenting with a sixth nerve lesion. CASE: A 33-year-old woman, gravida 2, presented at 38 weeks' gestation with sixth nerve palsy. She was hypertensive and proteinuric, with plasma urea of 24 mg/dL. Labor was induced and hypertension escalated in the early puerperium, with concomitant worsening diplopia. Blood pressure control and resolution of preeclampsia were followed by resolution of the sixth nerve lesion. There was no evidence of other pathology on extensive investigations. CONCLUSION: Sixth nerve palsy is an unusual manifestation of preeclampsia.

Abducens Nerve↗

Peptide glyoxals: a novel class of inhibitor for serine and cysteine proteinases.

A series of novel synthetic dipeptides, containing a C-terminal glyoxal grouping (-COCHO), have been tested as inhibitors against typical members of the serine- and cysteine-proteinase families. For example, the sequences benzyloxycarbonyl (Cbz)-Pro-Phe-CHO (I) and Cbz-Phe-Ala-CHO (II), which fulfil the known primary and secondary specificity requirements of chymotrypsin and cathepsin B respectively, have been found to be potent reversible inhibitors of their respective target proteinase. Thus I was found to inhibit chymotrypsin with a Ki of approximately 0.8 microM, whereas II exhibits a Ki of approximately 80 nm against cathepsin B. These Ki values are some 10-fold and 3-fold lower than those reported for the corresponding peptide-aldehyde inhibitors of chymotrypsin and cathepsin B upon which the peptidyl-glyoxals were fashioned. Unexpectedly, the sequence Cbz-Pro-Ala-CHO, which was designed to inhibit elastase-like proteinases, exhibited no inhibitory activity towards porcine pancreatic elastase, even when used at concentrations as high as 200 microM.

Animals↗

Detection of the fertile phase from changes in cervico-vaginal fluid volume.

Characteristic changes in cervico-vaginal fluid (CVF) volume which occur during the menstrual cycle might be used to detect the fertile phase. Twenty-five normal women were asked to withdraw CVF and measure its volume at home using a small, disposable, graduated vaginal aspirator. In 16 cycles day 0 (ovulation) was defined as the day of maximum follicular diameter according to serial ultrasound examination. A rise in CVF volume occurred between day -9 and -2 and a peak between day -4 and 0. In these sixteen, and in a further 72 cycles, day 0 (time of maximum fertility) was taken as the day of peak cervical mucus secretion. CVF volume rose, on the average, on day -6.2 (range -17 to -2) and peaked on day -0.8 (range -5 to +2). In two cycles, no rise and peak were identified. Changes in CVF volume were easy to recognise and could be useful to couples wishing to achieve pregnancy.

Adult↗

Oxygen saturation during transfer from operating room to recovery after anaesthesia.

Transcutaneous oxygen saturation of haemoglobin was measured in 101 patients en route from the operating room to the recovery room. Twenty-nine became significantly hypoxaemic during the journey. The incidence of hypoxaemia was not found to relate to age, weight, duration or type of surgery, type of anaesthesia or pre-existing disease. Duration of the interval between cessation of oxygen in the operating room and arrival in recovery room was the only significant finding in patients who became hypoxaemic.

Adolescent↗

Parainfluenza virus bronchiolitis. Epidemiology and pathogenesis.

An investigation of the epidemiology and pathogenesis of bronchiolitis due to parainfluenza virus (PV) was carried out. Bronchiolitis due to PV occurred most commonly in non-Caucasian males. Breast-fed infants exhibited a reduced risk of developing bronchiolitis. Once an episode of PV bronchiolitis occurred, both exposure to cigarette smoke and bottle feeding were associated with an increased frequency of recurrent wheezing, and subsequent infection with respiratory virus almost uniformly resulted in wheezing. Cell-mediated immune responses to PV antigen and titers of PV-specific IgE were greater among patients with bronchiolitis than among patients with upper respiratory tract infection. The epidemiology and pathogenesis of bronchiolitis due to PV is similar to that of respiratory syncytial virus. Lower respiratory tract infection may predispose to episodes of bronchoconstriction on subsequent exposure to cigarette smoke or other viral infections.

Antigens, Viral↗

Hypercalcemia: long-term follow-up with matched controls.

Using laboratory tests and the presence of complaints thought to be associated with hyperparathyroidism, we retrospectively studied 160 patients found to have hypercalcemia on a routine multiphasic examination in two different calendar years. Each case was compared to a matched control, and mean follow-up was 8.5 yr. The diagnosis of presumptive hyperparathyroidism was made by attempting to eliminate any confounding causes of hypercalcemia and by performing parathyroid hormone assays in 41 unoperated patients. Fifteen patients had a parathyroid adenoma removed (12 during and 3 after the duration of the study). Except for an increase in the incidence of hypertension in black male patients, we noted no significant differences in symptomatology or renal function between patients and matched controls. We conclude that most patients with mild persistent (presumptive) hyperparathyroidism may be left untreated under surveillance for long periods of time without the development of significant complications.

Adenoma↗

Role of parainfluenza virus-specific IgE in pathogenesis of croup and wheezing subsequent to infection.

In order to determine the role of parainfluenza virus-specific IgE antibody production and release of histamine in the pathogenesis of lower respiratory disease caused by parainfluenza virus infection, we studied 84 infants and children at the time of parainfluenza virus infection. Parainfluenza virus-IgE antibody was detected in samples of nasopharyngeal secretions by means of an enzyme-linked immunosorbent assay, and histamine content of nasopharyngeal secretions was determined by a fluorometric technique. Virus-specific IgE responses appeared earlier and were of greater magnitude in patients with croup, wheezing, and croup with wheezing caused by parainfluenza virus infection than in patients with parainfluenza virus-induced upper respiratory illness. Histamine was detectable in nasopharyngeal secretions of patients with parainfluenza virus-related croup significantly more often than in patients with upper respiratory illness caused by parainfluenza virus. These observations suggest a role for immunologic mechanisms in the pathogenesis of severe forms of respiratory illness caused by parainfluenza virus infection.

Antibodies, Viral↗

Reserpine and breast cancer.

After a series of studies on the linkage of reserpine with breast cancer, both evidence and interpretation appeared to be in conflict. Our case-control survey of long-term, comprehensive records from the Kaiser Foundation Medical Care Program, on 108 hypertensive breast cancer cases and 324 hypertensive controls, matched by year of birth and by race, produces a significant positive association between reserpine use and breast cancer. However, the association vanishes upon further matching with respect to the year of the first hypertension diagnosis and the subsequent length of follow-up. We thus fail to support suspicions of causality.

Age Factors↗