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211.
212.
Samples of chorionic villi were obtained in the first trimester by aspiration using a cannula passed transcervically under the guidance of real time ultrasound. In initial studies in 47 anaesthetised patients immediately before therapeutic abortion a method was developed giving a success rate of 89%. In 10 patients successful sampling was performed as an outpatient procedure without anaesthesia. In all, seven diagnostic procedures were undertaken and four of the five unaffected pregnancies continued. The technique of chorionic villous sampling using real time ultrasound is simple to learn and yields material for biochemical analysis and chromosomal study without the need for tissue culture. The exact obstetric risk, however, remains to be defined.  相似文献   
213.
Summary The horseradish-peroxidase (HRP) technique was used to visualize the cell bodies of axons projecting to the goldfish pituitary. Following intravenous injections of HRP, HRP reaction products were observed in axons of the rostral pars distalis, proximal pars distalis, neurointermediate lobe, pituitary stalk and in axons coursing from the pituitary into the hypothalamus. HRP-labelled cells in the brain were localized in two regions only — the nucleus preopticus (NPO) pars magnocellularis and pars parvocellularis, and the nucleus lateralis tuberis (NLT) of the hypothalamus. These observations suggest that the NPO and NLT are the source of the neurosecretory innervation of the goldfish pituitary.  相似文献   
214.
In the experiments on the anesthesized cats sodium hydroxybutyrate and piracetam, in contrast to glyo-6, have been shown to slow down the growth rate of creatine phosphokinase activity in the blood of the coronary sinus during 60-min occlusion of the coronary artery. At the same time, in the experiments on rats with 3-day myocardial infarction GABA derivatives like glyo-6 failed to influence the final size of cardiac necrosis. It may be concluded that anti-ischemic action of some drugs may be expressed only in the reduction of the rate of ischemic lesion development in the heart, but not in the limitation of the infarction size.  相似文献   
215.
216.
The primate cochlear nuclear complex exhibits several characteristic morphological differences in the various primate families from Lorisidae through Hominidae. The most striking differences occur in the organization of the dorsal cochlear nucleus in which the laminar pattern becomes progressively obscured. Granule cells form an external granular layer as well as being intermixed within the molecular and pyramidal layers in slow lorises and squirrel and rhesus monkeys. Whereas a prominent external granular layer remains in chimpanzees, granule cells are scant in other portions of the nucleus. Human adults lack an external granular layer. A small number of granule cells occur but with inconstant distribution. Primates lack the linear array of pyramidal cells oriented perpendicularly to the epithelial surface as seen in cats. The granule cell layer exhibits similar regression in development of the human cochlear complex. The external granular layer is prominent in the fetus but rapidly decreases in size after birth. It achieves its adult form prior to 18 months. The data suggest that neuronal attrition, or programmed cell death, may be the major mechanism accounting for the alterations that occur in the human granule cell layer. Other differences in cytoarchitecture, within the great apes and humans, include decreases in the small and giant cell populations of the cochlear complex. These changes, in consort with the organizational changes and reduction of granule cells as noted above, suggest a trend towards reduced intranuclear integration at the level of the cochlear nucleus coupled with encephalization of the auditory system.  相似文献   
217.
The enzymatic nature of 5'-monodeiodination (5'-D) in avian liver homogenates was demonstrated by abolishment of activity by iopanoic acid (IOP). T3 production from T4 was dependent on enzyme and substrate concentrations, incubation time, incubation temperature, and pH. Two pathways of 5'-D activity were present in avian liver and exhibited characteristics similar to those described in mammalian tissues. Type II activity was identified as propylthiouracil (PTU)-insensitive activity. Type I (PTU-sensitive) was determined by difference between Total and Type II. Km values were 1.58 microM T4 for Total activity and 0.90 nM T4 for Type II, corresponding to the characteristics of the mammalian pathways. The effects of goitrogens on avian hepatic 5'-D were equivalent to those reported for the mammalian enzyme.  相似文献   
218.
The polycation protamine sulfate increases microvascular permeability in the kidney by reducing glomerular charge. We have exposed the pulmonary vasculature to protamine sulfate to determine whether electrical charges play a role in protein permeability in lung vascular beds. In anephric rats, protamine sulfate increased hematocrit approximately 25%. With protamine sulfate doses of 0.08 and 0.04 mg/g body wt, lung blood-free wet-to-dry weight ratios were increased (5.24 +/- 0.8 and 4.89 +/- 0.7) compared with control (3.85 +/- 0.3) (P less than 0.05). In isolated, ventilated, and perfused lungs 0.04 mg/g body wt protamine sulfate increased pulmonary arterial pressure from 5.2 +/- 1.4 to 16.3 +/- 3.9 mmHg (P less than 0.01). These lungs gained weight and lung wet-to-dry weight ratios were significantly increased (15.33 +/- 4.26 compared with 6.04 +/- 0.24 for control lungs). Poly-L-lysine, another polycation, also caused significant increases in pulmonary arterial pressure, lung weight, and lung wet-to-dry weight ratios. The addition of diphenhydramine to the perfusate 10 min before the addition of protamine sulfate did not prevent these changes. Heparin (90 U/mg protamine sulfate) reversed the abnormalities. Pulmonary arterial pressure (7.0 +/- 1.1 mmHg) was not significantly different from the control value, lung weight did not increase, and the lung wet-to-dry weight ratio was 6.24 +/- 0.23 (P greater than 0.05). We conclude that polycations have a significant effect on pulmonary vascular resistance and perhaps on permeability.  相似文献   
219.
An active site-tyrosine-containing heptapeptide from D-amino acid oxidase   总被引:1,自引:0,他引:1  
The flavoenzyme D-amino acid oxidase (Eo) is rapidly chlorinated by N-chloro-D-leucine (Rudie, N.G., Porter, D.J.T., and Bright, H.J. (1980) J. Biol. Chem. 255, 498-508). We have carried out chymotryptic digestion of E0-36Cl2 and find that all of the radiolabel is located in a heptapeptide having [3.5-36Cl2]chlorotyrosine as the COOH-terminal residue. This heptapeptide, having the sequence -Asp-Leu-Glu-Arg-Gly-Ile-Tyr-, is located within a larger fragment obtained previously from cyanogen bromide cleavage of E0. These results demonstrate that the target for chlorination in E0 must be a single tyrosine residue and provide, when taken together with previous findings, the first clear evidence for the identity and location of an active site residue in the polypeptide chain of D-amino oxidase.  相似文献   
220.
An intranuclear microsporidium is described from hemoblastic cells of the chinook salmon, Oncorhynchus tshawytscha. The infection is associated with an acute anemia in the fish. Up to 47% of the hemoblast nuclei were infected in anemic fish. The organisms, found only in spleen and kidney tissues, were 1–2 μm in diameter and consisted of vegetative and early sporulation forms. This microsporidium differs from known species which parasitize fish in its tissue location; however, the absence of mature spores and other life cycle stages precludes determination of its precise taxonomic identity.  相似文献   
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