Virus infection and hand papular dermatoses in young children

Four strains of enterovirus and 1 strain of adenovirus were isolated from stool and pharyngeal swabs by inoculation into primary human embryonic kidney cell culture in 25 cases of dorsum manus infantile papular dermatitis. Two strains of Coxsackie A-9 virus and 1 strain of Echovirus-25 were identified. With the isolated virus as antigen, a matched pair study by sera antibody test was carried out in 43 children with papular dermatitis and 40 normal individuals as controls. In 26 cases of Coxsackie A-9 virus positive papular dermatitis, a 4-fold rise (> 1:1.6) in the relative serum antibody was observed in 80.77%, while no high levels were observed in patients with Echovirus-25 and adenovirus dermatitis (< 1:16). The authors can reasonably conclude that epidemic Coxsackie A-9 virus infection is obviously related to infantile papular dermatitis and is probably the main cause of the disease.

Genomic organization of the human c-kit gene: evolution of the receptor tyrosine kinase subclass III

The c-kit proto-oncogene encodes a transmembrane tyrosine kinase receptor. It belongs to receptor tyrosine kinase subclass III, which also includes the colony-stimulating factor I receptor (c-fms), platelet-derived growth factor receptors A and B (PDGFRA and PDGFRB), as well as FLT1 and FLT3/FLK2. c-kit and PDGFRA, c-fms and PDGFRB, FLT1 and FLT3/FLK2 are grouped by pair in three clusters in man on chromosome 4 band q11-q13, chromosome 5 band q31-q33 and chromosome 13 band q12 respectively. Here, we report the genomic organization of the human c-kit gene, which is composed of 21 small coding exons, distributed over 80 kb. Comparison of the c-kit and c-fms oncogenes shows that they share identified exon/intron boundaries in their two kinase domains, as well as a similar exon/intron organization in the extracytoplasmic domain. Comparison with the kinase domains of tyrosine kinase genes not belonging to subclass III suggests that the exon/intron organization of c-kit and c-fms is a characteristic feature of subclass III. The genomic similarities between c-kit and c-fms, in conjunction with the location in pairs on different chromosomes of the subclass III genes, has led us to hypothesize that cis and trans duplications gave rise to this group of genes.

Temperature dependence of drug blockade of a calcium-dependent potassium channel in cultured hippocampal neurons

The temperature dependence of drug blockade of a calcium-dependent potassium channel K(Ca) has been studied in cultured CA1 hippocampal neurons. Channel openings from a 70-pS K+ channel were recorded when inside-out patches were exposed to a bath solution containing 140 mM K+ and 0.2 mM Ca2+. The mean open times of channel events were not significantly altered when the bath temperature was lowered from 24 degrees to 14 degrees C (Q10 = 1.2). Introduction of the drug RP-62719 into the bath solution (at 5 microM) resulted in the mean open time of the K(Ca) channel to be diminished by 85% (at 24 degrees C) with no change in the amplitudes of the unitary currents. Over the same temperature range of 24 degrees to 14 degrees C, in the presence of RP-62719, the mean open times were significantly prolonged (Q10 = 2.2). A simple open channel block scheme was used to determine the temperature dependence of the onward- (blocking) and off- (unblocking) rate constants. Thermodynamic analysis, using transition rate theory, showed that the blocking rate constant was associated with a large increase in entropy. The relatively high temperature dependence for channel blockade is not consistent with a rate-limiting process established by simple diffusion of the agent to a channel blocking site. Channel block may involve conformational changes in the channel protein as a consequence of hydrophobic interactions between drug and channel sites.

Actions of cardiac drugs on a calcium-dependent potassium channel in hippocampal neurons

The patch-clamp method has been used to determine the actions of three newly synthesized cardiac drugs on a calcium-dependent potassium channel, K(Ca), in CA1 hippocampal neurons. Activation of a 65-pS channel was evident in excised inside-out patches with the internal side of the membrane exposed to Ca2+ (0.2 mM); cessation of channel activity was immediate upon perfusion with ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid-containing solution. In the presence of low concentrations (0.1-10 microM) of the drugs UK-68798, KC-8857 (tedisamil), or WY-48986 (risotilide), channel openings evinced rapid flickering behavior from open to nonconducting levels; current amplitude was not affected by the drugs. The actions of the drugs were consistent with a voltage-independent block of open K(Ca) channels. In addition, the three drugs, at concentrations similar to those applied to inside-out patches, also blocked K(Ca) when they were applied to the bath solution for outside-out patches. The potencies for channel block of the drugs acting either externally or internally were in the order UK-68798 greater than tedisamil greater than risotilide, with UK-68798 reducing the mean open time of K(Ca) by one-half at a concentration near 0.4 microM.

Clinical significance of hysterography in the diagnosis of choriocarcinoma and invasive mole

From 1963 through 1988, a total of 194 hysterographies were performed for 111 patients. Three types of abnormalities were observed on the hysterogram: filling defect, intramural invasion of the uterine wall by the contrast medium; and intravasation of the contrast medium into the pelvic veins. The pathology and clinical significance of three types of abnormalities were studied. The results showed that hysterography demonstrated better images than pelvic arteriography and B-scan for the diagnosis of choriocarcinoma and invasive mole, especially when combined with B-scan/or pelvic arteriography, a greater accuracy was achieved.

The effect of intrauterine devices, the stainless steel ring, the copper T220, and releasing levonorgestrel, on the bleeding profile and the morphological structure of the human endometrium--a comparative study of three IUDs. A morphometric study of 96 cases

Thirty-four women using the stainless steel ring (SS), 43 women using the Copper T220 (TCu), and 19 women using levonorgestrel-releasing intrauterine devices (LNG) were admitted to the study. The light microscopic biopsy material was subjected to morphometric studies including 8 indices of endometrial activity before (Control) and after 24 months of exposure to the SS and TCu device and 3-10 months of exposure to the LNG device. The women were grouped into subjects with and without intermenstrual and prolonged bleeding. The results revealed that there were highly significant differences between the IUDs at the endometrial level as displayed by morphometry. However, the difference between bleeders and non-bleeders was not significant in any of the three types of IUDs. Although the mode of action of these IUDs at the endometrial level is different, the mechanism responsible for the irregular endometrial bleeding needs to be further investigated.

Specificity of acute effects of Cd on renal function

Renal reabsorption of a typical low-molecular weight protein (cytochrome c) by rats was compared in controls and in rats acutely poisoned with CdCl2 (20 mumol/kg i.p., together with 300 mumol mercaptoethanol), HgCl2 (3 mg/kg i.m.), or NiCl2 (10 mg/kg i.p.). The effects of these metals on reabsorption of filtered cytochrome c were expressed in terms of changes induced in total protein excretion and in urinary concentrating ability. On this basis, only Cd exerted an acute specific effect on transport of cytochrome c, similar to its production of low molecular weight proteinuria following chronic exposure. At the time of the experiments the animals contained only low Cd levels in the renal cortex (7 micrograms/g). We conclude that the acutely injected rat can serve at least to some extent as a valid model for the study of Cd nephrotoxicity and that cytochrome c is a useful probe for the study of Cd-induced low molecular weight proteinuria.