Assembly and crystallization of the complex between the human T cell coreceptor CD8alpha homodimer and HLA-A2

A strategy for overexpression in Escherichia coli of the extracellular immunoglobulin domain of human CD8alpha was devised using codon usage alterations in the 5' region of the gene, designed so as to prevent the formation of secondary structures in the mRNA. A fragment of CD8alpha, comprising residues 1-120 of the mature protein, excluding the signal peptide and the membrane-proximal stalk region, was recovered from bacterial inclusion bodies and refolded to produce a single species of homodimeric, soluble receptor. HLA-A2 heavy chain, beta2-microglobulin and a synthetic peptide antigen corresponding to the pol epitope from HIV-1 were also expressed in E. coli, refolded and purified. CD8alpha/HLA-A2 complexes were formed in solution and by co-crystallization with a stoichiometry of one CD8alpha alpha dimer to one HLA-A2-peptide unit.     

New methods for transurethral electroresection of the prostate from the anesthesiologic viewpoint

Intravascular absorption of large volumes of solution without electrolytes is a common problem in transurethral resection of the prostate. In the present study we compared two different methods of resection (TURP vs. Vaporization TURP; 20 patients in each group) regarding fluid absorption and loss of blood. In addition, we report on 60 patients who had Vapo-TURP. The operations were performed by different very experienced surgeons. In both groups, spinal anaesthesia and standard regimes of infusion were used. The amount of fluid absorbed was measured by the ethanol method (2 vol.% ethanol; Widmark-formula). Haemoglobin, haematocrit and electrolytes were determined at set times. Ten of the 20 patients in the TURP group showed blood-alcohol levels > 0.1%/1000. In the Vapo-TURP group, only five of 57 patients (three patients with perforation of the prostate capsula were excluded) showed positive levels of blood-alcohol (< 0.05%/1000; fluid absorption < 150 ml). The difference was statistically significant (p = 0.002). Sixty minutes after the beginning of the procedures, the values of haemoglobin and haematocrit were significantly lower in the TURP group (7.68 +/- 0.41 vs. 7.38 +/- 0.64 mmol/l and 0.36 +/- 0.02 vs. 0.34 +/- 0.03). Regarding absorption of fluid and bleeding, Vapo-TURP was superior. From the anaesthesiological point of view, Vapo-TURP should be the method of choice, especially for the elderly.     

Elevated levels of IL-8 in dengue hemorrhagic fever

AIMS: To characterise retinal function using electrophysiological and psychophysical tests in 17 patients with helicoidal peripapillary chorioretinal degeneration. METHODS: The electroretinogram (ERG) was recorded using gold foil corneal electrodes. The electro-oculogram (EOG) was recorded using a standard protocol. Dark adaptometry was recorded with an SST-1 dark adaptometer and colour vision assessed with Ishihara plates and Farnsworth D-15. RESULTS: All subjects had a recordable ERG. The amplitudes and implicit times of the a- and b-waves were within normal limits at all luminances in five subjects (age 21-70 years, mean 40 years). The ERG of six (age 26-55 years, mean 40.7 years) had subnormal amplitudes at all luminances, but normal implicit times, and six (age 38-81 years, mean 60.7 years) had abnormal ERGs with marked reduction of a- and b-waves, and delayed implicit times of the b-wave. The implicit times of the a-wave were normal in all subjects. A reduction in the b/a wave ratios was not found, nor was there selective loss of scotopic, mixed rod/cone, or cone responses. The light/dark ratio of the EOG was subnormal (150-185%) or abnormal (below 150%) in all but three subjects. Two patients with normal EOG showed normal ERGs in both eyes, but one had subnormal ERGs in both eyes. The scotopic sensitivity was normal in all subjects and dark adaptation showed a normal time course. Colour vision was normal in all patients. CONCLUSION: The results suggest that in most cases the function of the retinal pigment epithelium is affected by this disease before any changes in the function of the sensory retina are detectable by our methods, and that retinal dysfunction is focal rather than diffuse.     

Skin vasoconstriction effect of contact antiphlogistics

Five contact antiphlogistics were evaluated and compared to hydrocortisone by the human skin vasoconstriction assay in 20 volunteers. The test concentrations ranged from 10(-2) to 10(-6) w/w; the duration of occlusive application was 16 h. The substances could be ranked as follows in ascending order of activity (index values in relation to hydrocortisone).     

Flow cytometric analysis of T4:T8 splenic cell during dengue virus infection of mice

The present study was undertaken to investigate the effect of dengue type 2 virus (DV) and DV-induced cytokines (CF and CF2) on T lymphocyte subpopulations of spleen by flow cytometry. Following DV-ic inoculation in mice the percent number of CD4+ and CD8+ lymphocytes in the spleen was reduced, the peak reduction in both was observed on the 6th day post-inoculation (p.i.). Intravenous inoculation of CF or CF2 in mice also decreased the percent number of CD4+ as well as CD8+ T lymphocytes subpopulation in the spleen, the maximum reduction being observed at 1 and 2 hr, respectively. The reduction in T lymphocyte subpopulation by CF and CF2 was found to be dose dependent. Thus, the alterations of T lymphocyte subpopulations during DV infection are mediated via cytokines.     

Mineral nutrition and fertilizer response of grain sorghum in India — A review over the last 25 years

Researches on the mineral nutrition and fertilizer response of grain sorghum (Sorghum bicolor (L) Moench) carried out during the last 25 years in India are reviewed here. In general, N,P,K, Fe and Mn concentrations in vegetative plant parts decreased with crop age, while the concentrations of Ca, Mg and Cu increased. The concentration of N and P increased in panicle or grains of sorghum with advance in crop age. The seasonal change for other nutrients has not, however, been studied.Accumulation and uptake of N,P, and K by grain sorghum were characterized. Usually N and P accumulated slowly compared with the rapid accumulation of K in early crop growth stage and vice-versa in later stages of growth. As against the sizable mass of N and P into panicle, K was partitioned into stalk.Fertilizer responses to N and P were observed throughout India. Improved varieties and hybrids of sorghum responded to N rates ranging from 60 to 150 kg N ha^–1, whereas a response to P application was observed up to 40 kg P ha^–1. Although responses to K application had been inconsistent, an increase in grain yield of sorghum was observed due to 33 kg K ha^–1. A balanced fertilizer schedule consisting of 120 kg N ha^–1, 26 kg P ha^–1, 33 kg K ha^–1 and 15–25 kg Zn50₄ ha^–1 is recommended for improved productivity of grain sorghum.It is concluded that systematic research efforts should be directed so as to identify problem soils showing deficiencies and toxicities of different nutrients. Characterization of the seasonal changes in the concentration and uptake of different nutrients and determination of critical concentration and hidden hunger of different nutrients in plant tissues would lead to the recommendation of balanced fertilization for different sorghum-growing regions in India.A part of the paper presented in the Silver Jubliee Conference of Indian Society of Agronomy held at H.A.U., Hissar (India) in March, 1981     

The genome sequence of Rickettsia prowazekii and the origin of mitochondria

We describe here the complete genome sequence (1,111,523 base pairs) of the obligate intracellular parasite Rickettsia prowazekii, the causative agent of epidemic typhus. This genome contains 834 protein-coding genes. The functional profiles of these genes show similarities to those of mitochondrial genes: no genes required for anaerobic glycolysis are found in either R. prowazekii or mitochondrial genomes, but a complete set of genes encoding components of the tricarboxylic acid cycle and the respiratory-chain complex is found in R. prowazekii. In effect, ATP production in Rickettsia is the same as that in mitochondria. Many genes involved in the biosynthesis and regulation of biosynthesis of amino acids and nucleosides in free-living bacteria are absent from R. prowazekii and mitochondria. Such genes seem to have been replaced by homologues in the nuclear (host) genome. The R. prowazekii genome contains the highest proportion of non-coding DNA (24%) detected so far in a microbial genome. Such non-coding sequences may be degraded remnants of 'neutralized' genes that await elimination from the genome. Phylogenetic analyses indicate that R. prowazekii is more closely related to mitochondria than is any other microbe studied so far.     

CQI in the acute dialysis setting

When the acute dialysis program became an in‐house operation, the development and implementation of a CQI program was a priority. Quality indicators were identified. Clotting in the dialyzer, treatment delays, and catheter‐related infections were tracked. Based on our CQI data, it was clear from the beginning that there was a high incidence of dialyzer clotting, particularly on our patients on Extended Daily Dialysis (EDD) who were on heparin‐free dialysis. Heparin‐free dialysis is prescribed for high bleeding risk patients and for patients with heparin‐induced thrombocytopenia. There was a need to explore an effective way to maintain patency and longevity of the extracorporeal circuit as clotting not only results to blood loss but to loss of treatment time, which affects the efficiency and adequacy of the dialysis therapy. Our policy on no‐heparin dialysis was modified. Hourly saline flushes were changed to a more aggressive every‐15‐to‐30 minute flushes. In addition, "heparin rinse" or priming the extracorporeal circuits with 5000 units of heparin added to 1‐liter bag, except for HIT positive patients, was immediately implemented. After 2 months, clotting in the dialyzer on Extended Daily Dialysis was significantly reduced from 24% to 2%. Conclusion:  CQI in the acute dialysis setting is critical for a continuous cycle of evaluating and improving patient outcomes. Through the process of CQI, we were able to identify dialyzer clotting with our EDD as a quality of care problem and implemented a solution that was effective.     

Outcome and predictors of success of biofeedback for constipation

BACKGROUND: A study was undertaken to determine outcome and to identify predictors of success for biofeedback for constipation. METHODS: Patients who had at least one biofeedback session were evaluated whether or not they completed a treatment course. Parameters assessed included use of cathartics, number of spontaneous bowel movements per week, presence of rectal pain, number of biofeedback sessions and results of anorectal physiology. RESULTS: A total of 194 patients (59 male, 135 female) of median age 71 (range 11-96) years, including 30 with concomitant rectal pain, were treated. The median number of spontaneous bowel movements per week before treatment was 0. Some 35 per cent of patients had complete success (three or more spontaneous bowel movements per week with discontinuation of cathartics), 13 per cent had partial success (fewer than three spontaneous bowel movements per week with continued use of cathartics) and 51 per cent had no improvement. Neither patient age, sex nor duration of symptoms significantly affected outcome. Only 18 per cent of patients who had between two and four sessions had complete success, compared with 44 per cent of those who had five or more (P < 0.001). A total of 63 per cent of patients who completed the treatment protocol experienced complete success, compared with 25 per cent of those who self-discharged (P < 0.0001). CONCLUSIONS: This large study indicates that the success rate of biofeedback for patients with constipation is less than previously reported. However, the success rate improves significantly after five or more sessions and is significantly related to the patient's willingness to complete treatment.