Controversies in tuberculosis

Tuberculous infection among children continues to be a significant cause of morbidity. The symptom complex are so variable among children that the final diagnosis often rests on the laboratory tests. Proper interpretation of the tests, specially tuberculin test and radiographic studies, are necessary for establishing correct diagnosis. The usefulness of tuberculin test in both unimmunized and BCG vaccinated children is highlighted. BCG accelerated response as a test should be reserved for identifying serious form of pulmonary disease or CNS tuberculosis when the tuberculin test is negative. Radiographic assessment may be sensitive in some instances but not always specific and hence needs cautious interpretation. Tuberculosis among BCG vaccinated children though not uncommon, needs proper documentation. Current trends in the management of tuberculosis including CNS forms are briefly outlined.     

应激相关因素对护士生活质量作用模型的理论构建和结构方程分析

目的应用结构方程分析研究应激相关因素对护士生活质量的影响机制。方法通过随机抽样,采用生活质量综合评定问卷、压力反应问卷、生活事件量表、特质应对方式问卷、领悟社会支持量表、艾森克人格问卷对405名护士进行调查,并应用结构方程分析方法对其作用机制进行探索。结果在5个理论可行的竞争模型中获取了最佳模型(CMINDF2.344;GFI0.928;AGFI0.891;CFI0.945;RMSEA0.060),即应激相关5因素(压力反应、生活事件、社会支持、应对方式和个性特征)中除应对方式外均能直接影响生活质量,而应对方式则以其他应激相关因素为中介对生活质量产生间接影响,这5个因素均可互为中介对护士生活质量产生间接作用。结论结构方程分析方法证实应激对护士生活质量的影响是一个交叉作用系统,在干预应激对护士生活质量的影响时应综合运用直接和间接方法。     

Preterm Birth: Implications for Family Stress and Coping

The event of preterm birth represents a significant risk to the equilibrium of the family, often placing the family under significant stress. This paper is intended to assist neonatal nurses in understanding factors related to a family's appraisal of stress and strategies used for coping. Such factors are an important consideration in planning the most effective interventions to support optimal family adaptation to their preterm infant's birth. In identifying the best clinical approaches to supporting a family coping with the event of a preterm birth, nurses need to consider levels of the evidence that supports adoption of clinical intervention strategies. Working to reduce family stress and improve family coping ensures the most optimal home environment for the preterm infant to grow and thrive in after discharge.     

The mechanical and morphological properties of bone beneath internal fixation plates of differing rigidity

The internal fixation of diaphyseal fractures by bone plates is a well recognized treatment. The normal physiological stress of bone is reduced by plates that cause a negative balance of bone-remodeling processes. Many investigators have shown that the degree of stress protection is dependent on the rigidity of the plates. It was the aim of this study to quantify mechanical and morphological changes at different locations in a plated diaphyseal bone as a function of differing plate rigidity. Two types of plates with the same size but different materials were used. The stainless steel plates had a modulus of elasticity and bending stiffness 3.2 times higher than the carbon fiber reinforced carbon plates. Both types of plates were applied to the intact right and left femora of six foxhounds for 6 months. The stiffer stainless steel plates led to a significantly higher bone loss and correspondingly greater loss of mechanical properties. These effects were greatest directly beneath the plate and less with increasing distance from the plate.     

Prolactin responses to haloperidol in drug-free and treated schizophrenic patients

Summary The prolactin response to 5 mg haloperidol i.m. was studied in 12 schizophrenic patients in a drug-free state and after a month treatment with haloperidol, as a possible index of dopamine receptor sensitivity and occupancy. Blood samples were taken at times 0, 60, 90 and 120 minutes. The increase in PRL observed in the drug-free state disappeared after drug treatment. The PRL plasma levels after treatment with 60 mg haloperidol per os were higher than the maximal PRL responses after 5 mg i.m. The increases in baseline PRL caused by the treatment correlated positively to the reduction in the BPRS score. The test was also performed in a group of 11 patients chronically treated with haloperidol during a daily dose of 60 mg, and 15 days after reduction of the dose to 30 mg. PRL increases after 5 mg haloperidol i.m. were observed only after reduction of the dose. It is suggested that the prolactin response to haloperidol is an index of the occupancy of receptors that are involved in the PRL releasing mechanisms, and could be used to verify their blockade by the neuroleptics, especially in patients that do not respond positively to drug treatment.     

Coronavirus induced primary demyelination: indications for the involvement of a humoral immune response

Coronavirus MHV-JHM infection of rodents can result in demyelinating encephalomyelitis. We analysed histological changes induced by coronavirus MHV-JHM infection in Lewis rats. Besides an acute disease (AE), chronic panencephalitis (CPE) and subacute demyelinating encephalomyelitis (SDE) were induced. These disease types were differentiated by the incubation period, the localization of lesions, the type of tissue damage and distribution of virus antigen. In AE and CPE, virus antigen was detected in neurons, astrocytes and oligodendrocytes, whereas in SDE neurons lacked virus antigen. Viral nucleocapsid protein (N) was present in the cytoplasm and the spike protein (S) was displayed on the surface of infected neural cells. However, expression of S protein relative to N protein was severely impaired in SDE lesions. Quantitative analysis of infiltrating inflammatory cells revealed that the number of macrophages and T cells were similar in lesions of AE, CPE and SDE. In contrast to that, SDE lesions contained a significantly higher number of IgG + B cells and plasma cells. In addition active demyelinating SDE lesions displayed an enhanced IgG content and deposits of complement C9. These results indicate that virus induced primary demyelination could be a consequence of antibody mediated cytotoxicity. Furthermore, a reduction in the number of cells producing spike protein in the chronic forms of the disease indicates down-regulation of this protein, possibly mediated by anti-S antibodies.     

Effects of the phosphodiesterase inhibitor rolipram on the acoustic startle response in rats

Systemic administration of the phosphodiesterase inhibitor rolipram (0.05–10.0 mg/kg, IP) produced a rapid and dose-related increase in the amplitude of the acoustic startle response in rats. The (−) isomer was more potent than the (+) isomer in enhancing startle amplitude. Rolipram increased startle responses that were elicited by brief electrical stimulation of the ventral cochlear nucleus or nucleus reticularis pontis caudalis, two brainstem relay nuclei of the startle neural circuit. A low (5 μg) dose of rolipram produced an excitatory effect on startle following spinal (lumbar intrathecal) infusion but not following supraspinal (lateral ventricle) infusion. Rolipram (0.5 mg/kg, IP) excitation of startle was not blocked by drugs which differentially disrupt the release of monoamines (DSP4, reserpine + alpha-methylpara-tyrosine, reserpine + para-chloro-phenylalanine) or by drugs which differentially block monoamine receptors (haloperidol, prazosin, idazoxan, cinanserin, or cyproheptadine). The marked increase in startle seen following systemic rolipram injection is attributable, at least in part, on an action in the lumbar spinal cord that directly or indirectly facilitates neural transmission along the reticulospinal component of the startle reflex neural pathway. The startle reflex should be a useful behavioral test system for studying the mechanism of action of rolipram and related compounds purported to selectively inhibit calmodulin-independent forms of phosphodiesterase.     

Opsonization of yeast by the plasma of Biomphalaria glabrata (Gastropoda): a strain-specific, time-dependent process

Phagocytosis of yeast by haemocytes of Biomphalaria glabrata, intermediate host of Schistosoma mansoni, is influenced strongly by host plasma components, although it can occur without involvement of such factors. Plasma from two strains of B. glabrata which are resistant to S. mansoni differs in its opsonic properties from the plasma of a susceptible strain. This may reflect the principles which determine compatibility or incompatibility in this host-parasite system. Opsonization is a time-dependent process: short periods of incubation in plasma from all strains reduces subsequent phagocytosis in the absence of plasma factors, whereas longer incubation in resistant strain plasma is markedly opsonic. Haemocytes from all strains examined are equally competent in their recognition of either native or opsonized yeast.     

协同刺激分子CD28在结核杆菌抗原体外激活人外周血γδT细胞中的作用

目的 :为了探讨CD2 8协同刺激分子在结核杆菌 (Mtb)低分子多肽抗原体外激活人外周血γδ T细胞中的作用。方法 :采用激发型抗CD2 8单抗模拟第二信号 ,Mtb低分子多肽抗原作为刺激原 ,对纯化的人外周血T细胞进行体外刺激和培养 ;用流式细胞仪检测γδ T细胞上CD2 8分子的表达、γδ T细胞的增殖效应及活化的γδ T细胞上CD6 9分子的表达。结果 :人外周血γδ T细胞中有 5 0 %左右表达CD2 8分子 ;抗CD2 8单抗协同Mtb抗原可刺激γδ T细胞的活化和增殖 ;但抗CD2 8单抗或Mtb抗原单独刺激则无作用。活化的γδ T细胞表面表达CD6 9分子。结论 :Mtb抗原在选择性活化人外周血γδ T细胞时需要第二信号的参与 ;CD2 8在Mtb抗原激活γδ T细胞时可提供协同刺激信号 ;CD6 9可作为γδ T细胞的早期活化标志。     

Altered islet Beta-cell function before the onset of Type 1 (insulin-dependent) diabetes mellitus

Summary To define the glucose to insulin dose-response relationship before the onset of diabetes, we studied 22 nondiabetic co-twins of patients with Type 1 (insulin-dependent) diabetes mellitus and nine control subjects. All had intravenous glucose tests at 0.02, 0.1 and 0.5 g/kg and were followedup prospectively for at least 6 years. Seven twins developed diabetes a mean of 7 months later; the remaining 15 are now unlikely to develop diabetes. The seven pre-diabetic twins had higher fasting insulin levels than control subjects (4.2±2.0 vs 1.8±1.8 nmol/l; p<0.05); but lower glucose clearance (1.0±0.5 vs 1.9±0.7 %/min; p<0.05), first phase insulin response at 0.5 g/kg (21.1±23.2 vs 143±50 nmol/l; p<0.0001), and total insulin responses at 0.1 g/kg (p<0.05) and 0.5 g/kg (p<0.00005). Using a curve-fitting programme, the normal glucose to insulin relationship was lost in prediabetic twins who had lower coefficient of determination (R²) than control subjects (p<0.01). In contrast, 15 low-risk twins and their nine control subjects had similar fasting glucose and insulin levels, glucose clearance, R² and insulin secretory responses to different glucose loads. The positive predictive values of subnormal R² and subnormal first phase insulin response were 67 % and 58 % respectively. These observations demonstrate an altered glucose to insulin dose-response relationship and loss of maximum insulin secretory response to glucose before the onset of Type 1 diabetes.