Search PubMed⌕ Search

Biomedical subjects

R Jenkins

Publications and source records attributed to R Jenkins.

At least 145 records · Page 8Linked to original sources

Effects of centrally administered corticotropin-releasing factor (CRF) and alpha-helical CRF on the vocalizations of isolated guinea pig pups.

Intraventricular corticotropin-releasing factor (CRF) was administered to guinea pig pups both with a freehand injection technique and via indwelling cannula. Behavioral effects depended upon the technique used. The highest dose of CRF (5 micrograms) inhibited the vocalizing of pups in a subsequent isolation test only when CRF was given by freehand injection. The possibility that disturbance attendant to the freehand procedure can account for this difference is discussed. To determine the effect of endogenous CRF in the absence of additional disturbance, the CRF antagonist alpha-helical CRF (ahCRF) was administered with the indwelling cannula procedure. ahCRF enhanced vocalizing during the first 10 min, and enhanced locomotor activity during the last 10 min, of a 30-min isolation test. Overall, the results indicate that endogenous CRF reduces vocalizing and locomotion during social isolation and that under certain injection conditions exogenous CRF can exacerbate the behavioral effect. The results also demonstrate the potential impact of the technique used to administer exogenous CRF. Further, the prevailing view, that CRF mediates stress-related behavioral responses, is supported only if behavioral inhibition, rather than vocalizing or locomotor activity, is viewed as the stress-related response in this situation.

Animals↗

Patterns of alcohol consumption in white collar-workers--a cross-sectional and longitudinal study.

A 6-year follow-up of a cohort of male and female white collar workers in whom there was baseline information on alcohol consumption and access to data on sickness absence, promotion and labour turnover, revealed that even moderate alcohol and consumption in this population was associated with social costs for the employer and the employee, particularly in terms of sickness absence. The longitudinal examination of consumption in this study suggests that early intervention in a drinking career may reduce alcohol consumption and consequently avoid years of morbidity and sickness absence, as well as having a favourable influence on promotion prospects and labour turnover.

Adult↗

A six year longitudinal study of the occupational consequences of drinking over "safe limits" of alcohol.

Although much research has focused on the psychological, social, and economic consequences of heavy problem drinking, there has been far less attention paid to the consequences of "moderate" drinking. This study used a unique opportunity to carry out a six year follow up of a cohort of male and female white collar workers in whom there was baseline information on alcohol consumption and access to details on sickness absence, labour turnover, and promotion. It has provided evidence that even moderate alcohol consumption in the working population is associated with social costs for the employer and the employee, including substantial sickness absence, and lack of promotion in men, although the increase in labour turnover was not statistically significant. The longitudinal examination of consumption in this study suggests that early intervention in a drinking career may reduce alcohol consumption and consequently avoid years of morbidity and sickness absence, as well as having a favourable influence on performance and labour turnover.

Absenteeism↗

Two-step PCR in the retrospective diagnosis of enteroviral viraemia.

Enteroviral infections are potentially serious in man causing a variety of syndromes and a viraemic phase is probable in most patients. However, virological diagnosis is usually indirect by isolation of the agent from throat or stools when possible, and/or slow due to the need to titrate antibodies in paired sera. Because of its high sensitivity the polymerase chain reaction (PCR) offers the possibility of rapid detection of even low-grade viraemia. We have developed a 2-step PCR procedure adapted for enteroviruses and applied it to stored sera from patients with enteroviral meningitis. The acute sera from 7/12 patients were positive but the 4 convalescence sera tested, 2 of which had been positive at the acute phase, were negative. The assay should now be tested prospectively on serum and cerebrospinal fluid and could be developed for routine diagnosis.

Adolescent↗

Thrombosis of difficult intracranial aneurysms by the endovascular placement of platinum-Dacron microcoils.

Patients with symptomatic aneurysms that are not excluded from the cerebral circulation have a poor prognosis. Standard treatment is surgical exploration with direct clipping of the aneurysm. Because of their large size or relationship to the base of the skull, some aneurysms may not be suitable for direct surgical clipping and may require alternative treatment modalities. A prospective clinical and radiological study of seven patients treated with the endovascular placement of platinum-Dacron microcoils to exclude the aneurysm from the cerebral circulation is reported. The seven patients ranged in age from 37 to 63 years; four were women. At completion of the endovascular procedure, total occlusion of the aneurysm with preservation of the parent artery had been achieved in four patients and 90% occlusion of the aneurysm in two. In the seventh patient, occlusion of the internal carotid artery resulted in the patient's death. At the 6-month follow-up review, both patients with an aneurysm less than 20 mm in size had persistent aneurysm thrombosis; however, the two patients with giant aneurysms had partial recanalization. Both required repeat thrombosis of their aneurysm with the placement of additional microcoils, one at 6 weeks and one at 6 months. These two patients have persistent aneurysm thrombosis at 12 months following their second procedure. The patient mortality rate for this study was 14%, while the procedure mortality/morbidity rate was 9%. It is concluded that thrombotic aneurysm therapy of difficult aneurysms is a safe procedure and will have a place in the treatment of selected aneurysms.

Adult↗

Long-term increase in the levels of c-jun mRNA and jun protein-like immunoreactivity in motor and sensory neurons following axon damage.

The immediate early genes c-fos, c-jun and NGFI-A are rapidly and transiently expressed in neurons of the superficial dorsal horn following noxious sensory stimulation. However, using either in situ hybridisation to map mRNA or specific antibodies to detect the protein products we were unable to detect any change in expression of those genes in stimulated dorsal root ganglion cells or motor neurons. In contrast levels of c-jun mRNA and protein-like immunoreactivity (but not c-fos or NGFI-A) are massively increased within dorsal root ganglion cells and motor neurons following sciatic nerve section or crush. However, these changes are neither rapid nor transient. Increased gene product is seen at 24 h but not 2 h after nerve damage and these levels are maintained up to seven days later. These results suggest that there are multiple routes for the control of c-jun gene expression within the nervous system and that c-jun may play a key role in the neuronal response to injury.

Animals↗

A 5-year study of cryosurgery in the treatment of liver tumors.

This report summarizes our 5-year experience with cryosurgery for in situ ablation of liver tumors. The liver was exposed with laparotomy, and the tumors were subjected to two freeze-thaw cycles using liquid nitrogen delivered by insulated probes; cryoablation was monitored with intraoperative ultrasonography. Tumor markers and computed tomography evaluated tumor response during long-term follow-up. From 1985 to 1990, 32 patients (19 men and 13 women) were entered into this study. The histologic characteristics of the tumors were as follows: colorectal, 24 patients; hepatoma, three patients; neuroendocrine, two patients; and others, three patients. After a follow-up period of 5 to 60 months (median follow-up, 24 months), nine patients (28%) remained disease free, 11 patients (34%) were alive with disease, and 12 patients (38%) died. The patterns of failure included liver and extrahepatic disease in 54% of cases, liver disease only in 32% of cases, and extrahepatic disease only in 14% of cases. In patients with "liver only" failure, recurrence at the treatment site occurred in three patients (9%). This study establishes the long-term effectiveness of cryosurgery in the treatment of primary and metastatic liver tumors.

Adult↗

Stable isotope studies of nicotine kinetics and bioavailability.

The stable isotope-labeled compound 3',3'-dideuteronicotine was used to investigate the disposition kinetics of nicotine in smokers, the systemic absorption of nicotine from cigarette smoke, and the bioavailability of nicotine ingested as oral capsules. Blood levels of labeled nicotine could be measured for 9 hours after a 30-minute intravenous infusion. Analysis of disposition kinetics in 10 healthy men revealed a multiexponential decline after the end of an infusion, with an elimination half-life averaging 203 minutes. This half-life was longer than that previously reported, indicating the presence of a shallow elimination phase. Plasma clearance averaged 14.6 ml/min/kg. The average intake of nicotine per cigarette was 2.29 mg. A cigarette smoke-monitoring system that directly measured particulate matter in smoke was evaluated in these subjects. Total particulate matter, number of puffs on the cigarette, total puff volume, and time of puffing correlated with the intake of nicotine from smoking. The oral bioavailability of nicotine averaged 44%. This bioavailability is higher than expected based on the systemic clearance of nicotine and suggests that there may be significant extrahepatic metabolism of nicotine.

Administration, Inhalation↗

Post-viral fatigue syndrome. Epidemiology: lessons from the past.

This chapter outlines the recorded epidemiological history of PVFS (including the early epidemics of myalgic encephalomyelitis) and the development of the concept, including the realisation that endemic cases also occur. Cases of PVFS are still not recorded by the Surveillance Centre for Communicable Diseases, so it is very difficult to detect and monitor any outbreak in the community, since each GP may only have two or three such patients and would, therefore, not be aware of an epidemic in the community as a whole if it occurred. Epidemiological issues raised by the early epidemics, including the delineation of the syndrome, the question of bias, the role of hysteria and the role of depression; the issue of symptom distribution, and its implications for aetiology; and a multiaxial framework for understanding the association with psychological symptoms are discussed. The value of a future multidisciplinary research programme designed to disentangle direct and predisposing causes of PVFS is emphasised.

Disease Outbreaks↗

Abdominal CT findings after liver transplantation in 66 patients.

CT scanning is used frequently to assess the condition of patients after liver transplantation. The CT records of 174 adult patients who underwent liver transplantation were studied retrospectively to determine the number and timing of CT studies as well as the frequency and significance of the findings. One-hundred seventy CT scans were obtained in 66 (38%) of the 174 patients, with a mean of 2.6 scans/patient. The interval between transplantation and scanning was 1 day to 24 months; in 59 (89%) of 66 patients, the first CT scan was obtained within 30 days. The acute indications for CT scanning were fever or leukocytosis in 54 (92%) of 59 patients and abnormal liver function tests in five (8%) of 59 patients. CT scans obtained more than 30 days after transplantation were repeat scans in all but seven patients. Indications in this latter group were the same as for the acute group, plus evaluation of hepatic neoplasia in three patients. CT findings included periportal low attenuation in 41 (62%) of 66 patients; ascites in 25 (38%); splenomegaly in 19 (29%); loculated intraperitoneal noninfected fluid collections in 13 (20%); intrahepatic, splenic, pancreatic, or perihepatic abscesses in seven (11%); hepatic infarction in six (9%); splenic infarction in three (4%); and hepatic calcification in two (3%). Other major abnormalities included inferior vena caval thrombosis (one patient), pseudoaneurysm of the hepatic artery with rupture (one patient), and recurrent hepatocellular carcinoma (one patient). CT scanning after liver transplantation is used predominantly in the acute setting to evaluate for liver infarction or intraabdominal abscess. In this setting, CT showed these abnormalities, in addition to tumor recurrence or vascular abnormalities, in 15 (23%) of 66 patients.

Ascites↗

Disability and social stratification.

This paper suggests that, for a variety of reasons, the sociology of social stratification--and, as a consequence, mainstream sociology more generally--has neglected the topic of disability. Using material drawn from a range of sources, it is argued that disability is related in definite ways to social class. Further, it is also argued that disability must be considered as a factor contributing to the production and reproduction of stratification in its own right, independently of class relations. These arguments are further advanced in the course of a more detailed consideration of research evidence concerned with mental handicap. The paper ends with a consideration of the role of non-class factors--specifically social status and citizenship--in the stratification systems of modern industrial societies.

Persons with Disabilities↗

A survey of community (out-of-hospital) sites used in pediatric training.

A survey was completed of US pediatric residency programs about the use of community sites in training. A total of 85% of program directors responded and reported a wide use of the 21 identified survey sites. Further study is needed to determine the appropriate contribution that community sites can make to pediatric training.

Internship and Residency↗