Actions and cross-reactivity of antiallergic agents and a calcium channel antagonist on rat peritoneal mast cells. Difference in the action mechanisms and cross-reactivity among the agents

The actions of the antiallergic agents, disodium chromoglycate (DSCG), tranilast and ketotifen, and of a calcium channel antagonist, nicardipine, and cross-reactivity among the agents were examined by observing the inhibition of⁴⁵Ca uptake and histamine release in rat mast cells stimulated by antigen and compound 48/80 (comp. 48/80).

1. All agents inhibited⁴⁵Ca uptake and histamine release in mast cells stimulated by antigen. The inhibition of⁴⁵Ca uptake by the antiallergic agents paralleled the inhibition of histamine release, while nicardipine inhibition of⁴⁵Ca uptake was stronger than its inhibition of histamine release.
2. The action of DSCG on⁴⁵Ca uptake and histamine release was significantly decreased in cells stimulated with antigen and phosphatidylserine (PS), while tranilast inhibition of histamine release was not affected by the addition of PS despite a significant decrease in the inhibition of⁴⁵Ca uptake.
3. The inhibitory effect of DSCG and tranilast was significantly lower in mast cells stimulated by comp. 48/80 than in the cells stimulated by antigen.
4. Tachyphylaxis was observed in cells re-exposed to DSCG and tranilast following previous exposure to the agents.
5. Cross-reactivity was found between DSCG and tranilast.

     

A simple organ culture method for differentiation of melanocytes in mouse embryonic skin using “origami” membrane filter

Summary A simple organ culture method for culturing embryonic skin was developed. A piece of skin with a part of the neural tube from mouse embryo (11 to 12 d) was placed on a 25 mm d membrane filter. The filter was folded to wrap the explant and inserted into glass tubing. The explant and filter in the glass tubing were placed in a rotating tissue culture tube containing 5 ml culture medium (Ham's F12 supplemented with 15 to 20% fetal bovine serum) and filled with a mixture of 95% air:5% CO₂. In explants cultured for 6 d fully differentiated melanocytes were observed in the epidermis.     

A nonsynonymous polymorphism in the human fatty acid amide hydrolase gene did not associate with either methamphetamine dependence or schizophrenia

Genetic contributions to the etiology of substance abuse and dependence are topics of major interest. Acute and chronic cannabis use can produce drug-induced psychosis resembling schizophrenia and worsen positive symptoms of schizophrenia. The endocannabinoid system is one of the most important neural signaling pathways implicated in substance abuse and dependence. The fatty acid amide hydrolase (FAAH) is a primary catabolic enzyme of endocannabinoids. To clarify a possible involvement of FAAH in the etiology of methamphetamine dependence/psychosis or schizophrenia, we examined the genetic association of a nonsynonymous polymorphism of the FAAH gene (Pro129Thr) by a case-control study. We found no significant association in allele and genotype frequencies of the polymorphism with either disorder. Because the Pro129Thr polymorphism reduces enzyme instability, it is unlikely that dysfunction of FAAH and enhanced endocannabinoid system induce susceptibility to either methamphetamine dependence/psychosis or schizophrenia.     

A patient with hepatic granuloma formation and angiotensin-converting enzyme production by granuloma cells during clinical relapse of hepatitis A

Elevation of the serum angiotensin-converting enzyme (sACE) level and hepatic granulomas were found during a clinical relapse in a 22 year old patient with acute viral hepatitis type A (AVH-A). The serum transaminase level and sACE level remained high for more than 6 months. In the biopsied specimen of the liver, fibrous rings of granulomas composed of collagen types I, III, and V were observed. Furthermore, the localization of ACE was visible in the rough endoplasmic reticulum of epithelioid cells of granulomas in the liver under electron microscopy using the indirect immunoperoxidase method. These results suggest that granuloma cells in the liver caused by hepatitis A may be involved in ACE production. In addition, other diseases associated with the presence of granulomas in the liver, such as lymphoma, cytomegalovirus infection, visceral leishmaniasis, and lupoid hepatitis, were ruled out. However, the hepatic granulomas disappeared with the healing of AVH-A. In this regard, the present case is considered to be one of the very few cases of hepatic sarcoidosis.     

Postnatal development of lymphatic vessels and their smooth muscle cells in the rat diaphragm: a confocal microscopic study

This paper reports on how lymphatic vessels and their smooth muscle cells develop in the diaphragm of postnatal rats. Lymphatic endothelial cells in the diaphragm were labeled by an intraperitoneal injection of DiI-labeled acetylated low-density lipoprotein (DiIac-LDL). During postnatal week 1, DiI-ac-LDL was detected in many free cells in addition to distinct endothelial cells that formed lymphatic vessels. Occasionally, saccular lymphatics isolated from previously formed lymphatics were recognized; these were referred to as lymphatic islands. The DiI-ac-LDL-labeled free and lymphatic endothelial cells showed immunoreactivity for CD 34 and Flt-4, but most of them did not express either OX 62 or ED 1 immunoreactivity, with only some showing ED 1 immunoreactivity. This suggests that most of the DiI-ac-LDL-labeled elements were lymphatic endothelial cells, and that some were macrophages. After postnatal week 1, the DiI-ac-LDL positive cells were restricted to lymphatic vessels. Until postnatal week 6, lymphatic vessels increased as the diaphragm enlarged. Towards the end of postnatal week 2, free cells expressing alpha-smooth muscle actin (alpha-SMA) immunoreactivity increased in the diaphragm, and some of these were in contact with lymphatics. A coarse plexus of smooth muscle cells surrounding the lymphatic vessels first appeared at postnatal week 2, and this plexus became denser with age. Our findings indicate that lymphatic vessels are formed not only by sprouting from previously formed lymphatic vessels but also by migrating endothelial cells, and that smooth muscle cells may be differentiated from mesenchymal cells to form a plexus surrounding the lymphatic vessels.     

Incidental prostatic carcinoma: Morphometry correlated with histological grade

Summary The histological grades of prostatic carcinoma, as defined by Gleason, were correlated with three methods of morphometry in 254 step-sectioned prostates obtained at autopsy. The variables studied were 1) the number of tumours in each prostate; 2) bilaterality and 3) tumour volume. Each characteristic yielded a statistically significant correlation with histological grade. The strongest correlations were obtained using tumour volume. These autopsy studied help to explain the inconsistent results obtained from morphometric analyses of surgical material, and lend support to the Gleason system as a means of predicting tumour behavior.Supported in part by research contracts PH 64-10, NCI-72-3213, N01-CP-53521; Grant R01-CA-33644; and the Grant-in-Aid for Cancer Research (33) from the Ministry of Health and Welfare     

The three-dimensional microvascular arrangement around rat dorsal hairs as revealed by scanning electron microscopy

The three-dimensional microvascular arrangement around the dorsal hairs in vascular corrosion casts of adult Wistar rats was studied by scanning electron microscopy. Each anagen dorsal hair was surrounded by a basket-like capillary network, which was supplied by the branches of the subcutaneous artery and drained into the veins continuous with the subcutaneous vein. The capillary network surrounding the anagen dorsal hair was denser at its lower part, and became more sparse at its upper part. Transmission electron microscopy showed that the capillaries around the hair bulb possessed fenestrations. Our findings indicate that the microvascular arrangement around the anagen dorsal hair is so organized as to supply the hair bulb, which is the most important area for hair growth, with abundant blood. This study was presented at the 24th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Okayama, September 17–19, 1992.     

Minimally invasive therapy under image guidance--emphasizing MRI-guided cryotherapy

Cryotherapy may provide a method for the focal destruction of cancerous tissue while preserving most of the surrounding normal tissue. The mechanisms of tissue injury in cryotherapy are 1) intracellular ice formation, 2) dehydration of cells, and 3) stagnation of microcirculation. MR images were superior to CT and ultrasound in monitoring interstitial cryotherapy, because the very short T2 relaxation time of ice affords excellent contrast between the ice and surrounding tissue, allowing an accurate depiction of the entire extent of the iceball. MR imaging demonstrates the iceball as sharply marginated regions of signal loss that expanded and engulfed the renal and hepatic masses with clear contrast between the iceball and surrounding tissue. Recently, a fast Joule-Thomson cryocycling device for MR-compatible cryotherapy application was developed and clinical trials under MRI-guided monitoring were performed in several sites of the body. In our series, cryotherapy was performed in 14 cases of renal tumor and 4 cases of hepatic malignancy under the guidance of a horizontal open MR system. Fourteen of the 18 cases were discharged a day after cryotherapy. One of the residual tumors at the margin of a renal cancer required re-cryoablation. All cryoablated tumors resolved and there were no serious complications and no clinically significant changes-during the follow-up study.     

Quantitation of varicella-zoster virus DNA in patients with Ramsay Hunt syndrome and zoster sine herpete

Varicella-zoster virus (VZV) reactivation causes facial nerve palsy in Ramsay Hunt syndrome (RHS) and zoster sine herpete (ZSH) with and without zoster rash, respectively. In the present study, we analyzed the VZV DNA copy number in saliva samples from 25 patients with RHS and 31 patients with ZSH using a TaqMan PCR assay to determine differences in the viral load between the two diseases. VZV copy number in saliva peaked near the day of the appearance of zoster in patients with RHS. Consequently, VZV DNA was less frequently detected in patients with RHS who exhibited facial palsy several days after the appearance of zoster. These findings suggest that the VZV load in saliva samples reflects the kinetics of viral reactivation in patients with RHS. In addition, VZV DNA was equally detected in saliva from patients with RHS and ZSH, and there was no significant difference in the highest viral copy number between patients with RHS and those with ZSH. The VZV load does not appear to reflect a major difference between RHS and ZSH.