Heat-shock protein (HSP70-2) allelic frequencies in three distinct Mexican populations

The major histocompatibility complex (MHC) genes are highly polymorphic and therefore have been useful in population genetics and disease association studies. We analyzed restriction fragment length polymorphism of HSP70-2 alleles in healthy unrelated Mestizo, Mazatecan and Nahua populations. Both Indian groups, Mazatecans and Nahuas, were in Hardy-Weinberg equilibrium, while Mestizos were in disequilibrium (chi 2 = 0.399; P < 0.05). The Mazatecan Indians presented a high frequency of BB homozygosity (17.35%) compared to Mestizos (5%) (P = 0.01). Mexican ethnic groups present differences in distribution of BB genotype. The low frequency of BB genotype in Mestizos may be the result of a negative selection process.     

Platelet adhesion onto segmented polyurethane film surfaces modified by addition and crosslinking of PEO-containing block copolymers

Polyethylene oxide (PEO) surfaces were prepared by the addition of PEO-containing amphiphilic block copolymers as surface modifying additives and of dicumyl peroxide (DCP) as a crosslinking agent in segmented polyurethane (PU). PEO-polypropylene oxide-PEO triblock copolymers (Pluronics) with different PEO chain length (from 0 to 98) were used as the surface modifying additives. The PEO additives in the PU film were then crosslinked to be stably entrapped in the PU matrix. The crosslinking was done by free radicals produced from the decomposition of DCP in the film through heating (120 degrees C) or ultraviolet irradiation (254 nm). The surface properties of the PEO additive-entrapped PU films were investigated by the measurement of water contact angles and electron spectroscopy for chemical analysis. The bulk properties such as water absorption, long-term film stability, and tensile strength and elongation at break, were also investigated. It was observed that addition of a small amount (5 wt% based on PU) of the PEO additives resulted in a considerable change of surface characteristics. The PEO additives were stably entrapped in the PU films by crosslinking of them, without significant changes of bulk properties of the films. From the platelet adhesion test on the prepared PEO additive-containing film surfaces, it was observed that the platelet adhesion on the surfaces decreases with increase in PEO chain length of PEO additives. The film surface containing additive with long PEO chains (chain length of 98) was particularly effective in preventing platelet adhesion. The crosslinking of the PEO additives in PU films did not affect the behavior of platelet adhesion on the surfaces; the films with crosslinked PEO additives showed similar platelet adhesion on the surfaces to the films with uncrosslinked ones.     

Expression and changes of HSP70 in the rat forebrain subjected to gamma knife (100Gy) irradiation targeted on the caudate putamen and survived for different times

Forebrain heat shock protein 70 (HSP70) immunohistochemical reactivity was investigated in rats subjected to gamma knife irradiation focusing on the right caudate putamen nucleus. The forebrain sections of all experimental animals were processed with anti-HSP70 antiserum and then by avidin-biotin peroxidase complex immunohistochemistry after gamma ray irradiation with a dose of 100Gy and they each survived for different times (from 30 min to 30 days). Some neurons, glial cells, and endothelial cells were HSP70-like immunoreactivity (HSP70-LI) positive. HSP70-LI was mainly distributed in the target area of irradiation, as well as in non-target regions, e.g. the cortex, hippocampus, and hypothalamus, etc. The expression and change of HSP70-LI from 3 h to 30 days after irradiation followed the following rules: (1) Within 3 to 24 h, the dilated vessels with HSP70-LI endothelial cells were found at first, and a few lightly stained HSP70-LI neurons and glias were observed in the target and non-target regions; (2) In 3-7 days, darkly stained HSP70-LI neurons and glias were apparently increased and formed an expression peak. From 14 to 30 days, HSP70-LI cells were distinctly decreased and became weakly stained or negative. These results suggested that although the irradiation target of the gamma knife was localized, the response to irradiation occurred extensively.     

Sonographic findings of breast hamartoma: emphasis on compressibility

The characteristic features of hamartoma in terms of discrepancies in mammographic and sonographic shapes of the mass were evaluated. We reviewed 16 pathologically proven breast hamartomas, which had undergone preoperative mammography and ultrasonography. All masses were analyzed according to ACR-BIRADS on mammography. On sonography, each mass was analyzed for size, shape, margin, internal echogenicity, and posterior acoustic enhancement. We also analyzed the echogenicity of halo, and compared the characteristic changes in the shape of hamartomas attributable to compression in mammograms and sonograms. The most common sites were at 12 o'clock in the right breast and 2 o'clock in the left. The most common mammographic findings of the hamartomas were a round shape (11/16), a circumscribed margin (13/16), internal fat densities (D4)(16/16) and radiolucent halos (14/16). The most common sonographic findings of the hamartomas were an oval shape (16/16), circumscribed margins (10/16), heterogeneous internal echogenicity (14/16), echogenic (7/16) or echolucent halos (5/16), and posterior enhancements (12/16). The characteristic feature of hamartomas was a change of the mammographic round shape mass into an elongated oval shape mass by sonography (11/11), suggesting the compressibility of hamartomas. Three of the hamartomas contained a pathologically proven internal calcification. The presence of a hamartoma was suggested by a change in a mammographic round mass with a radiolucent halo into an oval heterogeneous mass surrounded by an echogenic or echolucent halo on the sonogram. This characteristic difference between the mammographic and sonographic findings was attributed to the hamartoma compressibility, and was associated with the over-proliferation of fat containing mature normal breast tissue.     

Molecular weight determination and fractionation of poly(L-histidine) by gel filtration

Dextran gel filtration (using Sephadex G-75 gel) with a continuous monitoring system was applied to the determination of the molecular weight and for fractionation of poly(L -histidine), poly[imino-1-(4-imidazolylmethyl)-2-oxoethylene], (PLH). PLH was eluted satisfactorily with a pH 2,35 buffer, whereas it was adsorbed to the gel with a pH 5,40 buffer. The weight-average and number-average molecular weights (M_w and M_n) were determined from the calibration plot of molecular weight, obtained with proteins, and corrected by the Smith method. A highly fractionated “monodisperse” PLH with M_w/M_n = 1,14 to 1,22 was obtained from PLH with M_w/M_n = 1,43 by the use of a pH 4,95 acetic acid/ammonium acetate buffer.     

Projections from the hypothalamus and its adjacent areas to the posterior pituitary in the rat

Cholera toxin conjugated horseradish peroxidase was injected into the posterior pituitary and its afferents traced in 21 albino rats. The neuronal processes as well as the perikarya were elaborately displayed. The principal and retrochiasmatic supraoptic nuclei and the magnocellular paraventricular subnuclei were densely labelled. The accessory cell groups or nuclei labelled included: the medial preoptic and anterior hypothalamic areas, the anterior and posterior fornical nuclei, the lateral hypothalamic area, the nucleus circularis and nucleus of the forebrain bundle and hitherto unknown or not fully appreciated retrochiasmatic area, the dorsal accessory groups in an area between the stria medullaris and fornix, on the one hand, and the stria terminalis and internal capsule, on the other, and a well developed subependymalperiventricular zone. The medial preoptic nucleus, subfornical organ and organ vasculosum laminae terminalis were also weakly stained. Dendrites of the magnocellular paraventricular nucleus have been said by some to be largely confined to the subnuclei in which they lie. Immunohistochemical studies have proved that they extended beyond their nuclear confinement. The present study has found much wider extension of their dendritic fields. In fact, dendrites of the magnocellular neurosecretory cells in general were long and had a certain degree of directional bias. Several sites projecting to the posterior pituitary were closely related to the cerebrospinal fluid. Namely, the subependymal neuronal plexuses along the third ventricle and beneath the interventricular foramen, and the subpial dendritic plexuses of the supraoptic and retrochiasmatic supraoptic nuclei. Neurons were seen to squeeze in-between the ependymal cells, bringing themselves very close to the cerebrospinal fluid. No direct cerebrospinal fluid-contacting elements, either cell bodies or processes, however, could be ascertained. It is proposed that these plexuses may monitor changes in the cerebrospinal fluid. Besides the principal neurohypophysial tract the posterior pituitary was found in the present study to receive its afferents via two accessory fasciculi, one coursing in the medial forebrain bundle and the other running along the lateral wall of the infundibular recess subependymally.     

An analogy between fetal haptoglobin and a potent immunosuppressant in cancer

In spite of the numerous reports indicating the presence of humoral immunosuppressive factors in cancer patients, only a few of these factors have been biochemically identified. Furthermore, their role as effective immunosuppressors in vivo remains to be established. Our laboratory has attempted to isolate and identify the major immunosuppressive factor in the malignant effusions derived from ovarian and lung cancer patients. We have previously demonstrated that the Mr 52,000 immunosuppressive factor isolated from the ascites fluid of an ovarian cancer patient inhibited T-dependent immune responses in vivo and in vitro including the inhibition of E-rosetting. Thus, this immunosuppressive factor was named "suppressive E-receptor" (SER). Our current study demonstrates that this SER factor purified from malignant effusions derived from ovarian, lung, or head and neck cancer patients had a common component which dissociated equally into Mr 38,000-42,000 and 17,000-19,000 moieties on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under vigorous reducing conditions. Electroelution of these two components followed by a limited amino acid sequence determination revealed these two components to have N-terminal amino acid sequences identical to the beta and alpha 2 subunits of normal adult haptoglobin. Immunoelectrophoresis of SER using a polyclonal antiserum to neonatal cord blood demonstrated that SER, unlike normal haptoglobin, has slower electrophoretic mobility than the normal adult haptoglobin. Western blotting analysis of SER separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions failed to recognize a monoclonal antibody directed specifically to SER. However, this monoclonal antibody exclusively reacted with the SER separated by an analytical polyacrylamide gel electrophoresis gel under nondenaturing conditions while normal adult haptoglobins or purified but denatured haptoglobin obtained from the same malignant fluid as SER all failed to react with this antibody. Thus, SER appears to bear an additional epitope(s) that is absent in normal adult haptoglobin. Since the SER as well as the neonatal haptoglobin have at least 100 to 1000-fold more potent immunosuppressive activity than the normal adult haptoglobin, this additional epitope(s) present in SER may be responsible for the potent immunosuppressive property of SER.     

瘦素受体Gln223Arg基因多态性与不同葡萄糖耐量血清瘦素的相关性研究

目的 :研究瘦素受体基因Gln2 2 3Arg等位基因与不同葡萄糖耐量中血清瘦素及其它代谢指标的关系。方法 :运用聚合酶链反应 限制性片段长度多态性 (PCR RFLP)方法测定无亲缘关系 ,不同葡萄糖耐量 198例北京地区汉族人的瘦素受体基因Gln2 2 3Arg等位基因 ,同时分析其与临床资料的相关性。结果 :不同等位基因型的瘦素水平无显著差异 ,而在葡萄糖耐量减低 (IGT)男性 ,Gln2 2 3Arg等位基因有较高的胆固醇水平 [(7 2 6±1 95 )和 (5 31± 1 31)mmol/L ,P =0 0 4]和较高的收缩压 [(18 8± 1 2 )和 (17 2± 1 6 )kPa ,P =0 0 3]。结论 :瘦素受体Gln2 2 3Arg基因多态性与不同葡萄糖耐量的血清瘦素无关 ,但与机体代谢有一定关系     

成人下凳骨第三磨牙阻生关系的研究

目的 观测成人下颌骨第三磨牙的阻生关系。方法 根据吴氏《人类骨骼测量方法》中规定的年龄估计及性别鉴定的标准,观测成人颌骨的形态结构。结果 302个下颌骨标本的观察结果为,男女混合阻生率为10.60％,女性阻生率高于男性,肉眼见无第三磨牙萌出者106例,经X线拍片验证,5例有埋没牙存在,故实际第三睡缺如率为33.44%。从测量数据可见阻生组（无第三磨牙组）的第二磨牙后间隙、下颌斜长、下颌体长及髁突间宽均较正常组小。结论 无第三磨牙可能是人类进化过程中,下颌骨与牙齿均衡退化的结果,而阻生是人类进化从有第三磨牙向第三磨牙演化的过渡阶段。