Site specific variations in rat adipose tisue transforming growth factor-α: Effects of age

Transforming growth factor alpha (TGF-α) was assayed in subcellular preparations obtained by sequential centrifugation of adipose tissue homogenates from epididymal and perirenal adipose tissue depots in young and aged rats. When expressed per unit wet weight, per mg protein or per fat cell, TGF-α activity in young rats was greater in the epididymal than in the perirenal depot. In aged rats, absolute quantity of TGF-α was significantly increased in the larger perirenal depot. This study demonstrates the presence of TGF-α in adipose tissue homogenates, and implicates this cytokine in the growth of adipose tissue. © 1993 Wiley-Liss, Inc.     

Beta-adrenergic receptor involvement in the mediation of learned taste aversions

Drug-induced stimulation or blockade of beta-adrenergic receptors in the lateral hypothalamus has been reported to enhance or reduce, respectively, the normally supressive affect of quinine adulteration on sweet milk consumption in rats. Subsequently, it was hypothesized that the beta-receptors may function analogously in the mediation of learned taste aversions. In order to test this hypothesis we conditioned rats to avoid a preferred aqueous solution of saccharin (0.1% w/v) by pairing it with a toxic injection of 0.4 molar lithium chloride (10 ml/kg i.p.). Three days later the rats were re-exposed to saccharin water 30 min after receiving a ventricular injection of either the beta-adrenergic agonist dl-isoproterenol hydrochloride (18 g) or the beta adrenergic antagonist dl-4-[2 hydroxy-3-isopropylaminopropoxy]-indole (32 g). As predicted, the beta-agonist further enhanced the avoidance of saccharin among animals already conditioned to avoid it, while the blocking agent attenuated the learned aversion. However, the influence of the drugs on drinking was similar among unconditioned control animals suggesting that their affects were independent of prior learning.This study was supported by State of Kansas D.I.M. Grant No. 0421-6-629-0101, and NICHHD Grant No. 002528-05, Bureau of Child Research, University of Kansas.     

Cardiopulmonary exercise testing in the evaluation of functional capacity after treatment of lymphomas in adults

The present study assessed several parameters of cardiopulmonary function in patients, after treatment for aggressive non-Hodgkin's lymphoma and Hodgkin's disease, to determine the influence of these parameters on patient's performance status. One hundred and six patients (66 male and 40 female) aged 40 +/- 15 years were examined 1-2 years (median 14 months) after anticancer treatment. The patients were examined by means of rest and dynamic stress echocardiography and cardiopulmonary exercise. The rest and post-exercise ejection fraction (EF), Doppler parameters of left ventricular diastolic function and peak oxygen consumption (pVO2) were used as parameters of cardiopulmonary performance. The cumulative dose (CD) of doxorubicin (DOX) given was 240 +/- 70 (240 mg/m2). Thirty-seven percent of patients received mediastinal irradiation in accordance with the used treatment protocol. Sixty-four patients (60%) experienced fatigue after the treatment. Three patients (3%) demonstrated an decreased EF <50%, 34 (32%) demonstrated impaired diastolic function, 14 (13%) demonstrated decreased pVO2<20 ml/kg/min and 15 (14%) demonstrated a value of pVO2 below the reference value, respectively. None of the patients exhibited clinical signs of heart failure. Apart from three patients with a rest EF<50%, all the other patients responded to stress echocardiography with an increment of EF > 5%. The parameter pVO2 significantly correlated with stress EF (0.58, P < 0.0002). A significant relationship was found with all parameters of diastolic function: to index E/A of diastolic filling (r = 0.67, P < 0.0001), isovolumic relaxation time (r = -0.56, P < 0.0009) and to deceleration time (r = -0.54, P < 0.009), respectively. A negative relationship was found with age (r = -0.74, P < 0.0001), CD of DOX (r = -0.53, P < 0.003) and radiotherapy-involving mediastinum (r = - 0.44, P < 0.04), respectively. Using multivariate analysis, a significant relationship was found between pVO2 and parameters of diastolic filling, age, female sex and CD of DOX, respectively (r = 0.58, P < 0.0001). Diastolic dysfunction was correlated with age, CD of DOX and radiotherapy-involving mediastinum, respectively (r = 0.51, P < 0.01). The results show that diastolic dysfunction was the most affected parameter of cardiopulmonary function in cancer survivors. This parameter negatively influenced cardiopulmonary performance and was significantly correlated with the cumulative dose of doxorubicin given and radiotherapy on mediastinum. Despite a high number of patients experiencing fatigue, the study demonstrates that only a relatively small number of patients show a depressed pVO2 on a cardiopulmonary stress test and other cardiac abnormalities. The results of the tests support the introduction of regular aerobic exercise for cancer survivors to increase their cardiopulmonary performance and well-being. Hypothetically, aerobic training may also positively influence diastolic function. However, this assumption warrants a prospective follow-up.     

Evaluation of acute and early cardiotoxicity in survivors of Hodgkin's disease treated with ABVD or BEACOPP regimens

The study was conducted to compare the presence of cardiotoxicity after the treatment of Hodgkin's disease with the standard ABVD or BEACOPP protocol. We examined 29 patients treated by means of the ABVD regimen and 34 treated with the BEACOPP regimen. Using rest echocardiography we assessed the left ventricular function before and after the therapy. One year after the completion of therapy, a control examination was performed with a battery of tests; the rest and dynamic stress echocardiography and cardiopulmonary tests were carried out to assess cardiopulmonary performance. A similar significant deterioration of ejection fraction and diastolic function was apparent after the treatment in both sub-groups with a further progression at the one-year control. Only one patient from the BEACOPP sub-group showed a pathological drop of EF <50%. The most affected parameters of left ventricular function (LV) were Doppler indices. We found a significant relationship of the parameters of LV function compared with age, the cumulative dose of doxorubicin and the cumulative dose of radiotherapy. Multivariate analysis demonstrated that diastolic dysfunction correlated with advanced age and the cumulative dose of doxorubicin, and decreased cardiopulmonary performance with advanced age, radiotherapy, and female gender. Both parameters were significantly influenced by the presence of hypertension. The used regimens demonstrated similar subclinical cardiotoxicity, thus the most aggressive regimen, BEACOPP, is not accompanied by a higher rate of cardiac impairment. The clinical value of such subclinical cardiotoxicity will be estimated in a further prospective follow-up.     

Secondary syringe exchange among users of 23 California syringe exchange programs

This article describes the secondary syringe exchange (SSE) practices of injection drug users (IDUs) attending 23 syringe exchange programs (SEPs) in the state of California during 2002 (n=539). The sample was primarily heroin injecting, about two thirds male, half White and half other racial/ethnic groups. Participants were interviewed with a structured questionnaire that included items on sociodemographic factors, drug use practices, sexual practices, use of SEP and other social services, and satisfaction with SEP services. Interviews lasted about 30 minutes. SSE was highly prevalent: 75% of IDUs reported participating in SSE in the 6 months before interview. Program characteristics, such as legal status, SSE policy, and exchange policy, did not affect the prevalence of SSE among SEP clients. Infectious disease risk behaviors were significantly more common among SSE participants than nonparticipants. SSE participants were more likely to share syringes (p<.001) and cookers (p<.001) in the previous 6 months. SSE was significantly associated with being stuck with another person's syringe (needle-stick), a little-discussed "occupational hazard" of this practice. In multivariate analysis, the adjusted odds ratio of needle-stick among SSE participants was 2.8 (95% confidence interval, 1.3, 6.0). The high prevalence of SSE and the infectious disease risk associated with it warrant additional research to determine the causality of these associations. In the interim, SEPs should consider reinforcing HIV prevention education messages and training IDUs who engage in SSE in safe handling of biohazardous materials.     

Effects of cell wall inhibitors on cell division in Streptococcus mutans

The addition of inhibitors of cell wall biosynthesis to exponential-phase cultures of Streptococcus mutans may do one of three things, depending on the concentrations used: (i) prevent cell division at a time coincident with the onset of chromosome replication, (ii) prevent cell division later in the cell cycle coincident with or near completion of septation, or (iii) lead to limited cell lysis. The relative tolerance of S. mutans to inhibitors of cell wall biosynthesis may be due to the fact that S. mutans cultures treated with low levels of cell wall antibiotics seem to be blocked at a stage before initiation of autolytic activity, whereas cultures treated with high levels of these antibiotics seem to be blocked after termination of the autolytic phase. Thus, the cells escape the lytic death that is seen in other streptococci exposed to inhibitors of cell wall biosynthesis.     

Psychiatric problems in the aged: a reconsideration

The numerically important mental disorders found in the senescent population are reviewed from the point of view of their relationship to the process of ageing. Only two direct relationships are seen: the acute confusional states due to the age-linked decline in stress resistance; and the neurotic reactions due to the diminished capacity for rapid and adequate adjustment to the more subtle but chronic sociopsychological changes the aged individual is so frequently exposed to in our society. The chronic dementing processes of the senium, senile and arteriosclerotic dementia, are more likely to occur at an advanced age, but apparently are not the final outcome of cerebral and/or cerebrovascular ageing, although the ageing process seems to favour their phenotypical manifestation. The functional psychoses may occur at an advanced age but are not directly related to the process of ageing.