Dose-response studies with thyrotropin-releasing hormone (TRH) in abstinent male alcoholics: evidence for selective thyrotroph dysfunction?

A reduced thyrotropin (TSH) response to thyrotropin-releasing hormone (TRH) has been reported in subjects with a history of alcoholism whereas prolactin (PRL) responses have generally been normal. One hypothesis proposed to explain the reduced TSH response is down-regulation of pituitary TRH receptors. If this is correct, PRL response should also be diminished. To account for the different dose-response characteristics of TSH/PRL we have given four dosages of TRH (25, 100, 500 and 800 micrograms) to eight noncirrhotic, male alcoholics abstinent from ethanol a minimum of 28 days and to seven male control subjects. Across the TRH dose range the alcoholic subjects exhibited reduced basal TSH (p = .01) and a reduced TSH response (p = .0023) but no differences in basal and stimulated PRL levels. Alcoholic subjects had higher basal T4, T3 and FT4I values than did control subjects but covarying for T4, T3 and FT4I did not change the significance of either TSH or PRL findings. No significant differences in estradiol, estrone, testosterone, cortisol or glucose were noted between groups. The present study confirms the observation of a lower TSH response to TRH in abstinent alcoholics and indicates that the lower response cannot be overcome by increasing TRH dosage. The similar PRL response between groups suggests normal lactotroph function in noncirrhotic abstinent alcoholics and argues against the pituitary TRH receptor down-regulation hypothesis.     

Lung tumor-associated derepressed alloantigen coded for by the K region of the H-2 major histocompatibility complex

Transplacental induction of lung tumors in C3HfeB/HeN (C3Hf) strain mice can be readily achieved with the carcinogen 1-ethyl-1-nitrosourea. Several of these tumors express, as a tumor-associated transplantation antigen (TATA), a normal tissue alloantigen present in strain A and C3H/HeN (C3H) mice. In the present study it was shown that the tumor-associated alloantigen on the C3Hf-derived lung tumor 85 was present in all mice of H-2(a) and H-2(k) haplotypes tested and in CBA (532) strain mice (H-2(ka) haplotype). Studies using congenic-resistant and recombinant strains of mice indicated that the genetic locus controlling the expression of this antigen was either within or to the left of the H-2K region of the major histocompatibility complex (MHC). Thus the antigen was expressed in B10.A (4R) mice (kkbbbb MHC haplotype) but not in B10 (bbbbbb) or B10.AQR mice (qkkddd). The antigen was expressed in all tissues tested of C3H and A strain mice. It was not detected on any tissue tested including embryo tissue of C3Hf mice or mice of MHC haplotype other than H-2(k) or H-2(a). Because C3Hf strain mice were originally derived from C3H strain mice (H-2(k)), the MHC haplotype of C3Hf mice has been provisionally designated H-2(kb). The finding of a tumor-associated change in the expression of a H-2K region-coded antigen is consistent with the concept that MHC-coded antigens may act as targets for immunological surveillance of tumors.     

Mixed lymphocyte reactivity and cell-mediated lympholysis to trinitrophenyl-modified autologous lymphocytes in C57BL/10 congenic and B10.A recombinant mouse strains

Cell-mediated lympholysis (CML) to trinitrophenyl (TNP)-modified autologous splenic lymphocytes has been recently reported in the mouse (1). Both the sensitization and effector phases of this phenomenon were shown to be T-cell mediated. Effector cell specificity studies indicated that modification of the target cells is a necessary but insufficient requirement for cytolysis, and suggested that altered cell surface components controlled by genes mapping in the mouse major histocompatibility H-2 complex (MHC) are important in the specificity of the cytotoxic reaction (1). In allogeneic models the generation of cytotoxic effector cells has been shown to be preceded or accompanied by immunogen- induced proliferation of responding lymphocytes, i.e. a mixed lymphocyte reaction (MLR) (2-5), although the generation of effectors may not necessarily always be the consequence of extensive cell proliferation (5). If the induction of cytotoxic effector lymphocytes by modified syngeneic spleen cells is characteristic of sensitization with cellular alloantigens, one would expect to find that sensitization with TNP-modified autologous cells would also induce thymidine incorporation by the responding cells in the culture. The present report demonstrates that both stimulation of thymidine incorporation and generation of cytotoxic effector cells are part of the in vitro response to TNP-modified autologous lymphocytes. However, the MLR to TNP- modified autologous cells consistently appeared to be less pronounced when compared with an allogeneic MLR, whereas the cytotoxic activity of the effector cells generated by sensitization against TNP-modified autologous cells was frequently as high as that detected against H-2 alloantigens. These two components of reactivity to “modified self” are verified in several C57BL/10 congenic and B10.A recombinant mouse strains.     

The provision of renal replacement therapy for adults in England and Wales: recent trends and future directions

We assessed the level of provision of renal replacement therapy for adults in England and Wales. All autonomous main renal units in England (n = 52) and Wales (n = 5) were surveyed in 1996. Data for England were compared to the 1993 National Renal Review. The acceptance rate in England 1995 was 82 (80-85) per million population (p.m.p.) compared with 67 (65-70) p.m.p. in 1991-2. The rate in 1995 in Wales was 109 (98- 122) p.m.p. The prevalence rate in England was 476 p.m.p. at end-1995 compared to 393 p.m.p. in 1993, in Wales it was 487 p.m.p. The number of main renal units in England did not rise between 1993 and 1995; capacity was increased by use of more treatment shifts and temporary haemodialysis stations, and by opening more satellite units. The main growth was in hospital haemodialysis. There was an uneven geographical distribution of services. Patients accepted were older with more comorbidity. The use of better-quality processes of dialysis increased. The steady-state position for RRT will not be reached for over a decade. Health authorities will face continued pressure to fund increases in quantity and quality improvements. A stronger evidence base of the effectiveness of therapies, and a national registry to monitor the equity and cost-effectiveness of services are needed.      

青少年和成年人无症状阻生智齿干预措施的疗效评价

目的评价在青少年和成人中拔除与保留无症状阻生智齿的效果.方法计算机检索Cochrane口腔健康组资料库(至2004年8月4日),Cochrane中心临床对照试验资料库(CENTRAL),Ovid-MEDLINE(1966～2004年8月4日),PubMed(1966～2004年8月4日)和EMBASE(1974～2004年8月4日).检索无语种限制.同时对主要相关杂志进行手检,并尽力获取正在进行和未发表的研究.纳入比较预防性拔除与保留阻生智齿效果的全部随机对照或临床对照研究.由3位作者分别独立评价所检出文献的相关性、真实性并提取数据,如有不确定性,联系作者以获取关于随机和失访的更多信息.对所有试验均进行了质量评价.结果共纳入3个研究,其中2个已完成的随机对照试验评价了青少年预防性拔除智齿对切牙拥挤的影响,另1个随机对照试验正在进行,但研究者不能提供任何资料,他们准备近期发表文章,如是,其资料将被纳入本评价的更新中.已完成的2个研究结局判断指标不同,不能进行数据合并.结论没有证据支持或反对常规预防性拔除成年人无症状阻生智齿,有一些可靠的证据表明在青少年预防性拔除阻生智齿既不能减少也不能预防切牙拥挤.     

Reciprocating tachycardia due to a right-sided unidirectional retrograde anomalous pathway (URAP).

An 8 year-old boy had extensive electrophysiological evaluation of his recurrent supraventricular tachycardias. His ECG never showed delta waves but intracardiac stimulation and recording disclosed the following (1) eccentric retrograde atrial activation; (2) increased cycle length and retrograde conduction time following the development of right bundle-branch block; (3) constant retrograde conduction time for increasingly premature ventricular stimuli; (4) atrial captures by ventricular stimuli when the atrioventricular-His pathways were refractory; and (5) no delta waves upon stimulation of the atrial input site of the anomalous pathway. A diagnosis of reciprocating tachycardia involving retrograde conduction through an accessory pathway was made. Reciprocating tachycardias involving a unidirectional retrograde anomalous pathway can be easily misdiagnosed as atrioventricular node reentrant tachycardias if no evidence of preexcitation can be found, particularly if the anomalous pathway is on the right side. In order to exclude the participation of a concealed unidirectional anomalous pathway in a patient's reentry tachycardia, a complete map must be made of right and left atrial endocardial activity.