Characterization of a novel HLA-DQB1 allele, DQB1*020102

A novel human leukocyte antigen (HLA)-DQB1 allele, DQB1*020102, was detected in a 28-year-old woman of Han ethnic in Guangzhou, China. Compared with HLA-DQB1*020101 and HLA-DQB1*0202, they differed in only one nucleotide at the position 167 (C to T) of exon 2, which was a highly conserved position. This is a synonymous mutation, which does not cause any change in the amino acid sequence of mature protein.     

Entrainment of Intestinal Slow Waves with Electrical Stimulation Using Intraluminal Electrodes

The aim of this study was to investigate whether the intestinal stimulation would be feasible using a less invasive method: intraluminal electrodes. The study was performed in nine healthy hound dogs (15–26 kg). Four pairs of electrodes were implanted on the serosa of the jejunum at an interval of 5 cm with the most proximal pair 35 cm beyond the pylorus. An intestinal fistula was made 20 cm beyond the pylorus. Simultaneous recordings of intestinal myoelectrical activity were made for 2 h in the fasting state from both intraluminal and serosal electrodes. Various pacing parameters were tested. The frequency of the intestinal slow wave recorded from the intraluminal electrodes was identical to that from the serosal electrodes , p < 0.001), and so was the percentage of normal 17–22 cycles/min waves (95.8±33.9% vs 98.16±1.33%, r=0.96, p<0.01).p < 0.01). A complete entrainment of the intestinal slow wave was achieved in every dog with electrical stimulation using intraluminal ring electrodes. The effective pacing parameters were pulse width of 70 ms, amplitude of 4 mA and frequency of 1.1 IF (intrinsic frequency). The time required for the entrainment of the intestinal slow wave with intraluminal pacing was 25.0±2.1s. The maximum driven frequency was found to be 1.43±0.01 IF. The results reveal that intraluminal pacing is an effective and efficient method for the entrainment of intestinal slow waves. It may become a potential approach for the treatment of intestinal motor disorders associated with myoelectrical abnormalities. © 2000 Biomedical Engineering Society. PAC00: 8754Dt, 8719Ff, 8717Nn     

CXCR4 and CCR5 expression on CD4+ T cells in vivo and HIV-1 antigen beta-chemokine production in vitro after treatment with HIV-1 immunogen (REMUNE)

BACKGROUND: The chemokine receptors CXCR4 and CCR5 have been identified as the major coreceptors for HIV-1 on CD4+ cells and macrophages. The natural ligands for these receptors are SDF-1 and the beta-chemokines (MIP-1alpha, MIP-1beta, RANTES), respectively, and are the products of a variety of immune cells, including CD8+ T lymphocytes. STUDY DESIGN/METHODS: We hypothesized that the ability to stimulate the natural ligands for these receptors using an immune based therapy might influence in vivo chemokine receptor expression. RESULTS: In vivo CXCR4 expression remained stable after treatment with an HIV-1 Immunogen (REMUNE), whereas CCR5 expression on CD4+ T cells decreased (p < .05). Furthermore, HIV-1 antigen-specific production of beta-chemokines in vitro was also augmented (P < .05). CONCLUSIONS: These preliminary results suggest that this HIV-1-specific immune-based therapy can stimulate antigen-specific beta-chemokine production in vitro and downregulate CCR5 receptor expression on CD4 cells in vivo.     

Significance of premature contractions of WPW type in the acute phase of myocardial infarction

Observations in 220 patients with myocardial infarction of an intensive care unit are reported. The distinctive features of premature ventricular contractions of WPW type are described. Production of premature contractions of this type in the acute stage of myocardial infarction is regarded as a premonitory sign of rhythm disorders of considerable significance. The electrophysiological and electropathological background of rhythm disorders is analyzed in close detail, particular consideration is being given to the implications of premature contractions of WPW type. Increasing electric inhomogeneity in the acute phase of myocardial infarction is illustrated by intracavitary electrocardiograms. A relationship has been found between the protracted repolarization of the hypoxic ventricular areas and the appearance of T-U complexes. Two distinct groups of premature ventricular contractions of WPW type with reference to the conductive system are described. The origin of the delta waves in the WPW syndrome is discussed.     

Search for correlates of protective immunity conferred by anthrax vaccine

Vaccination by anthrax protective antigen (PA)-based vaccines requires multiple immunization, underlying the need to develop more efficacious vaccines or alternative vaccination regimens. In spite of the vast use of PA-based vaccines, the definition of a marker for protective immunity is still lacking. Here we describe studies designed to help define such markers. To this end we have immunized guinea pigs by different methods and monitored the immune response and the corresponding extent of protection against a lethal challenge with anthrax spores. Active immunization was performed by a single injection using one of two methods: (i) vaccination with decreasing amounts of PA and (ii) vaccination with constant amounts of PA that had been thermally inactivated for increasing periods. In both studies a direct correlation between survival and neutralizing-antibody titer was found (r(2) = 0.92 and 0.95, respectively). Most significantly, in the two protocols a similar neutralizing-antibody titer range provided 50% protection. Furthermore, in a complementary study involving passive transfer of PA hyperimmune sera to naive animals, a similar correlation between neutralizing-antibody titers and protection was found. In all three immunization studies, neutralization titers of at least 300 were sufficient to confer protection against a dose of 40 50% lethal doses (LD(50)) of virulent anthrax spores of the Vollum strain. Such consistency in the correlation of protective immunity with anti-PA antibody titers was not observed for antibody titers determined by an enzyme-linked immunosorbent assay. Taken together, these results clearly demonstrate that neutralizing antibodies to PA constitute a major component of the protective immunity against anthrax and suggest that this parameter could be used as a surrogate marker for protection.     

A subset of gamma delta T-cell receptor-positive cells produce T-helper type-2 cytokines and regulate mouse skin graft rejection following portal venous pretransplant preimmunization.

C3H/HeJ mice received B10.BR skin grafts following portal or lateral tail vein infusion of irradiated B10.BR spleen cells. Thereafter mice were injected with anti-alpha beta or anti-gamma delta T-cell receptor (TCR) monoclonal antibody (mAb). Anti-gamma delta TCR mAb abolished the increased graft survival afforded by portal venous (p.v.) immunization, and reversed the bias towards expression of mRNA for type-2 cytokines [interleukin-4 (IL-4), IL-10] seen in lymphoid tissue of p.v.-immunized mice. When gamma delta TCR+ and alpha beta TCR+ cells were isolated from the intestinal epithelial compartment (IEL), liver or Peyer's Patch (PP) of p.v.-immunized mice, the gamma delta TCR+ cells were found to be enriched in cells producing type-2 cytokines on rechallenge with irradiated B10.BR cells in vitro. gamma delta TCR+ cells from p.v.-immunized mice were further expanded in vitro with anti-CD3 and cytokines (combined IL-2 and IL-4). Following expansion these cells were capable of adoptively transferring increased B10.BR skin graft survival to naive mice, and continued to show a bias in type-2 cytokine synthesis after allostimulation in vitro. When gamma delta TCR chain expression was assessed in cells taken from p.v.-immunized mice, or in cells expanded in culture, our data suggest that p.v. immunization leads to oligoclonal, not polyclonal, expansion of those gamma delta TCR+ cells involved in inhibition of graft rejection.     

Genetic analysis of a human rotavirus that belongs to subgroup I but has an RNA pattern typical of subgroup II human rotaviruses.

We have previously found (O. Nakagomi, T. Nakagomi, H. Oyamada, and T. Suto, J. Med. Virol. 17:29-34, 1985), during an epidemiological study in Japan, a novel human rotavirus that belongs to subgroup I but has a long RNA pattern typical of subgroup II human rotaviruses. From the stool specimen containing this virus, we successfully isolated in MA104 cells a rotavirus, designated AU-1, which possesses these novel characteristics. The possibility that strain AU-1 was a laboratory contaminant of an animal rotavirus previously adapted to tissue culture cells was ruled out, and the identity of the AU-1 strain was established. Genetic analysis by RNA-RNA hybridization revealed that the AU-1 strain is not a simple reassortant between subgroup I and II human rotaviruses but that it shares a high level of sequence homology only with the gene encoding VP7 (the major neutralization protein) of serotype 3 human rotaviruses. Weak homology of the genomic RNA segments was also observed between the AU-1 strain and animal rotavirus strains, including rhesus rotavirus strain RRV and bovine rotavirus strain NCDV. These results suggest that the AU-1 strain may be an animal rotavirus that infected a human.     

African trypanosome antigens recognized during the course of infection in N''dama and Zebu cattle.

The humoral immune responses to Trypanosoma brucei infection were examined in N'dama and in Zebu, two breeds of cattle recognized for their differing susceptibility to trypanosomiasis. Regardless of the clinical course, animals of both breeds produced antibodies to nonsurface trypanosome antigen(s) detectable by both immunodiffusion and immune fluorescence. As a new approach to assessment of the humoral response to trypanosome infection, protein antigens responded to were isolated by immune precipitation, and their molecular weights were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This allowed the detection of differences in the immune response which correlated with the clinical course of the disease. All cattle of both breeds which exhibited a capacity to control the disease recognized at least one of three specific antigens: protein of 110,000, 150,000, and 300,000 daltons. The N'dama, which proved less susceptible to the disease, generally responded to more of the three identified trypanosome protein antigens than did the Zebu. Animals which died of trypanosomiasis failed to produce detectable antibodies to any of the three specific proteins, although they sometimes exhibited antibodies to another trypanosome antigen.     

Cellular dysfunction in the diabetic fibroblast: impairment in migration,vascular endothelial growth factor production,and response to hypoxia

Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P < 0.001) and was not significantly stimulated by hypoxia (1% O(2)), whereas wild-type fibroblast migration was up-regulated nearly twofold in hypoxic conditions (P < 0.05). Diabetic fibroblasts produced twice the amount of pro-matrix metalloproteinase-9 as normal fibroblasts, as measured by both gelatin zymography and enzyme-linked immunosorbent assay (P < 0.05). Adult diabetic fibroblasts exhibited a sevenfold impairment in vascular endothelial growth factor (VEGF) production (4.5 +/- 1.3 pg/ml versus 34.8 +/- 3.3 pg/ml, P < 0.001) compared to wild-type fibroblasts. Moreover, wild-type fibroblast production of VEGF increased threefold in response to hypoxia, whereas diabetic fibroblast production of VEGF was not up-regulated in hypoxic conditions (P < 0.001). To address the question whether these differences resulted from chronic hyperglycemia or absence of the leptin receptor, fibroblasts were harvested from newborn db/db mice before the onset of diabetes (4 to 5 weeks old). These fibroblasts showed no impairments in VEGF production under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients.     

Detection of sperm in men with Y chromosome microdeletions of the AZFa,AZFb and AZFc regions

BACKGROUND: Y chromosome microdeletions are associated with severe male factor infertility. In this study, the success rate of testicular sperm retrieval was determined for men with deletions of AZF regions a, b or c. METHODS: AZF deletions were detected by PCR of 30 sequence-tagged sites within Yq emphasizing the AZFa, b and c regions. Semen analysis and diagnostic testis biopsy or testicular sperm extraction (TESE) findings were correlated with the specific AZF region deleted. RESULTS: A total of 78 men with AZF deletions included three with AZFa deletion, 11 with AZFb, 42 with AZFc, 16 with AZFb+c and six with Yq (AZFa+b+c). All men with AZFa, AZFb, AZFb+c and Yq deletions were azoospermic and no sperm were found with TESE or biopsy. Of men with isolated AZFc deletion, sperm were found in 75% (9/12) by TESE and 45% (9/20) on biopsy (56% overall); 62% (26/42) were azoospermic and 38% (16/42) severely oligozoospermic. A total of 7 patients with deletion patterns that included the complete AZFa region and 23 that included the complete AZFb region who underwent TESE or biopsy did not have sperm detected by these surgical measures. CONCLUSIONS: Microdeletion of the entire AZFa or AZFb regions of the Y chromosome portends an exceptionally poor prognosis for sperm retrieval, whereas the majority of men with AZFc deletion have sperm within the semen or testes available for use in IVF/ICSI.