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61.
Utilizing real-time computer image analysis, individual spermatozoawere selected using microaspiration. Selection criteria werebased on potential hyperactivation motility characteristics;the amplitude of lateral head displacement >7.5 µm,curvilinear velocity >70 µm/s and linearity of <30%.For this pilot study, 16 patients (eight in each group) wererecruited. Using subzonal insemination (SUZI), up to five (mean= 4.4 ± 0.3) spermatozoa selected using computer-imagesperm selection (CISS) were microinjected, or up to 15 (mean= 12.8 ± 1.3 SD) unselected spermatozoa. In the groupwhich utilized CISS, 28 out of 49 (57%) oocytes were fertilizedcompared with 13 out of 52 (25%) utilizing conventional SUZI(P < 0.04); polyspermy was 20% (n = 10) and 2% (n = 1) respectively.CISS with SUZI showed increased efficiency in achieving fertilizationand is a novel approach to studying individual sperm functionin a sperm egg bioassay where gamete ratios are close to unity.  相似文献   
62.
Oligostyryllithium was synthesized by the reaction of sec-butyllithium with styrene in diethyl ether at ?40°C. Dimer model anions (counter cations: Li and K) of the growing chain ends were synthesized by metallation of 1-methoxy-1,3-diphenylpropane. The structures of the lithium compounds were corroborated by 13C NMR spectroscopy and compared with those of the potassium compounds. As for polystyryllithium and its model compounds, the charge density on the α-carbon increased and that on the phenyl ring of the growing end decreased with increasing molecular weight, while, in polystyrylpotassium and its model compounds, the charge density on the α-carbon increased and the one on the phenyl ring did not change with increasing molecular weight. The temperature change of the 1H NMR spectrum of oligostyryllithium in diethyl ether indicated rotation around the C-1? Cα bond at lower temperatures than in tetrahydrofuran, but the activation energy was the same in both solvents. T1 values of the phenyl carbons in model compound 2b were one to two orders of magnitude shorter than those of the protonated compound.  相似文献   
63.
64.
Lymphocyte subsets in the tumor nests of breast carcinoma were immunohistochemically investigated and a quantitative analysis was added. The majority of cases showed predominance of T cell and suppressor T cell (T8). A decrease in number of lymphocyte subsets and the helper T (T4)/T8 ratio in the stroma of tumor nests correlated well with the progression of clinical stage and the presence of metastasis. This correlation could not be found in the peripheral region of the tumor nests. Macrophages and NK cells were infrequently observed only in the peripheral region of ductal carcinoma. T cell infiltration was prominent in medullary carcinoma with lymphocyte infiltration (MC), and macrophages, NK cells, and T zone histiocytes were frequently encountered. For the purpose of knowing the activity of T cells, IL-2 receptor (Tac) and transferrin receptor were examined irnmunohistochemically. The fact that a few activated T cells were found only in the peripheral region of tumor nest suggested the local immune response in ductal carcinoma not to be so active as to reject the tumor cells. Since numerous activated T cells were recognized in the tumor nests of MC, this type of breast carcinoma was thought to have a higher immune reactivity. There was little evidence indicating NK cells to play a role for natural cytotoxicity in breast carcinoma. ACTA PATHOL. JPN. 36 1455-1468, 1968  相似文献   
65.
Many plant and bacterial toxins act upon cytosolic targets and must therefore penetrate a membrane barrier to function. One such class of toxins enters the cytosol after delivery to the endoplasmic reticulum (ER). These proteins, which include cholera toxin (CT), Pseudomonas aeruginosa exotoxin A (ETA), and ricin, move from the plasma membrane to the endosomes, pass through the Golgi apparatus, and travel to the ER. Translocation from the ER to the cytosol is hypothesized to involve the ER-associated degradation (ERAD) pathway. We developed a genetic strategy to assess the role of mammalian ERAD in toxin translocation. Populations of CHO cells were mutagenized and grown in the presence of two lethal toxins, ETA and ricin. Since these toxins bind to different surface receptors and attack distinct cytoplasmic targets, simultaneous acquisition of resistance to both would likely result from the disruption of a shared trafficking or translocation mechanism. Ten ETA- and ricin-resistant cell lines that displayed unselected resistance to CT and continued sensitivity to diphtheria toxin, which enters the cytosol directly from acidified endosomes, were screened for abnormalities in the processing of a known ERAD substrate, the Z form of alpha1-antitrypsin (alpha1AT-Z). Compared to the parental CHO cells, the rate of alpha1AT-Z degradation was decreased in two independent mutant cell lines. Both of these cell lines also exhibited, in comparison to the parental cells, decreased translocation and degradation of a recombinant CTA1 polypeptide. These findings demonstrated that decreased ERAD function was associated with increased cellular resistance to ER-translocating protein toxins in two independently derived mutant CHO cell lines.  相似文献   
66.
Pregnancy-associated malaria (PAM) is an important cause of maternal and neonatal suffering. It is caused by Plasmodium falciparum capable of inhabiting the placenta through expression of particular variant surface antigens (VSA) with affinity for proteoglycans such as chondroitin sulfate A. Protective immunity to PAM develops following exposure to parasites inhabiting the placenta, and primigravidae are therefore particularly susceptible to PAM. The adverse consequences of PAM in primigravidae are preventable by intermittent preventive treatment (IPTp), where women are given antimalarials at specified intervals during pregnancy, but this may interfere with acquisition of protective PAM immunity. We found that Kenyan primigravidae receiving sulfadoxine-pyrimethamine IPTp had significantly lower levels of immunoglobulin G (IgG) with specificity for the type of parasite-encoded VSA-called VSA(PAM)-that specifically mediate protection against PAM than did women receiving a placebo. VSA(PAM)-specific IgG levels depended on the number of IPTp doses received and were sufficiently low to be of clinical concern among multidose recipients. Our data suggest that IPTp should be extended to women of all parities, in line with current World Health Organization recommendations.  相似文献   
67.
Age-related changes in the structure and replication of mitochondrial DNA (mtDNA) were investigated in different organs from young adult (9–10 months' old) and senescent (28–29 months' old) BALB/c mice and Fischer 344 rats. Total mtDNA from brain, heart, kidney and liver was isolated by centrifugation in ethidium bromide—CsCl gradient and examined for the occurrence of complex forms and replicative intermediates by electron microscopy. The frequency of catenated mtDNA (interlinked molecules containing two or more circular units) varied from about 2.5% to 5% in adult tissues and showed a small increase in the majority of senescent organs. The frequency of double-sized circular molecules, or circular dimers, was very low in adult tissues, with an average of about 0.04% in mice and 0.1% in rats. The frequency of circular dimers increased with aging to 1.9% in mouse brain and 1.5% in rat kidney, with smaller increases (0.4% and 0.7%) in heart mtDNA from both species; there was no significant increase in the other organs. It is suggested that the increase in the frequency of circular dimer mtDNA reflects an overall deterioration of tissue physiology rather than intrinsic senescent changes in the mitochondria. The frequencies and types of the various replicative forms of mtDNA varied significantly according to tissue but not according to species or donor age. The only exception was a significant increase in the frequency of larger replicative forms in senescent mouse liver, to about 20% compared with 12% in adult liver, suggesting an age-related change in the rate of mtDNA replication and/or turnover in this organ.  相似文献   
68.
Mutations of the GREAT gene cause cryptorchidism   总被引:7,自引:0,他引:7  
In humans, failure of testicular descent (cryptorchidism) is one of the most frequent congenital malformations, affecting 1-3% of newborn boys. The clinical consequences of this abnormality are infertility in adulthood and a significantly increased risk of testicular malignancy. Recently, we described a mouse transgene insertional mutation, crsp, causing high intraabdominal cryptorchidism in homozygous males. A candidate gene Great (G-protein-coupled receptor affecting testis descent), was identified within the transgene integration site. Great encodes a seven-transmembrane receptor with a close similarity to the glycoprotein hormone receptors. The Great gene is highly expressed in the gubernaculum, the ligament that controls testicular movement during development, and therefore may be responsible for mediating hormonal signals that affect testicular descent. Here we show that genetic targeting of the Great gene in mice causes infertile bilateral intraabdominal cryptorchidism. The mutant gubernaculae fail to differentiate, indicating that the Great gene controls their development. Mutation screening of the human GREAT gene was performed using DHPLC analysis of the genomic DNA from 60 cryptorchid patients. Nucleotide variations in GREAT cDNA were found in both the patient and the control populations. A unique missense mutation (T222P) in the ectodomain of the GREAT receptor was identified in one of the patients. This mutant receptor fails to respond to ligand stimulation, implicating the GREAT gene in the etiology in some cases of cryptorchidism in humans.  相似文献   
69.
70.
Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and punctureinduced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.  相似文献   
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