Human membrane cofactor protein (MCP, CD46) is widely distributed and is one of the plasma membrane complement inhibitors. We isolated cDNA clones encoding genetic homologues of human MCP from a rat testis cDNA library. Northern blot analysis indicated that rat MCP is preferentially expressed in testis, similar to what is found with guinea pig MCP. We identified several different cDNAs, which were presumably generated by alternative splicing from a single-copy gene. The most prevalent isoform corresponded to the Ser/Thr/Pro-rich C type of human MCP. Mouse MCP cDNA was cloned by polymerase chain reaction based on the nucleotide sequence of rat MCP. The deduced amino acid sequence showed 77.8% identity to rat MCP. Mouse MCP was also preferentially expressed in testis. Unique expression in testis in rat and mouse as well as guinea pig suggests that MCPs in these species not only act as complement regulatory proteins but may also have more specialized functions in fertilization or reproduction. Genetic mapping by linkage analysis indicated that the mouse Mcp gene is located on distal chromosome 1, closely linked to the complement receptor 2 (Cr2) gene.

Amino Acid Sequence↗

PubMedDate not supplied

Overloading a muscle does not alter the rate of motoneuronal loss in aged rats.

Effects of increased activity on neuronal cell death was investigated in the motor nuclei innervating normal and overloaded medial gastrocnemius (MG) muscles of Fischer 344 rats. The MG muscle was overloaded by the unilateral surgical ablation of synergists at the age of 17 months (group A) or 24 months (group B). When the rats reached the age of 24 and 28 months (group A) or 30 months (group B), motoneurons innervating the MG muscle were labeled bilaterally with horseradish peroxidase injected into the MG nerve. The wet weight of the muscle on the operated side was consistently heavier than that of the contralateral, intact side. The number of labeled neurons decreased with advancing age, and there was no difference in the magnitude of decline found between motor nuclei innervating intact and hypertrophied muscles. Thus, overloading the MG muscle did not retard or accelerate the age-related loss of motoneurons innervating this muscle. These findings indicate that the causal relationship between motoneuronal activity and death with advancing age needs to be studied further.

Age Factors↗

PubMedDate not supplied

Ca(2+)-responsive extensible monolayer membrane of calmodulin-albumin conjugate.

A Ca(2+)-responsive monolayer protein membrane was prepared by developing calmodulin and bovine serum albumin at the air-water interface and by conjugating them with a bifunctional agent. In the case of the BSA monolayer, complex formation with Mg2+ generated a larger change in surface pressure than that with Ca2+. On the other hand, a drastic change in surface pressure was observed for the conjugated thin membrane associated with Ca2+ than that associated with Mg2+. Due to a drastic change in the conformation of calmodulin, the conjugated protein film changes its morphology (STM image), depending on Ca2+ concentration: the extended structure in the presence of Ca2+ transforms to a shrinked structure in the absence of Ca2+. The largest surface pressure change was detected when calmodulin was mixed with an equimolar amount of bovine serum albumin.

Calcium↗

PubMedDate not supplied

Immunohistochemical localization of calcitonin gene-related peptide in the human gastric mucosa.

BACKGROUND/AIM: There have been only a few studies on the distribution of calcitonin gene-related peptide (CGRP) in the human stomach, in which it was stated that CGRP fibers are rare in that organ. The aim of the present study was to investigate the immunohistochemical localization of CGRP in the human gastric mucosa obtained by endoscopic biopsy from patients with gastric ulcers. METHODS: Immunohistochemistry was carried out according to the indirect immunoperoxidase method using an anti-human CGRP antibody. Biopsies were taken from the ulcer margin in 18 patients (age 37-78, average 57.4 years) and from two endoscopically normal portions (antrum and body) in 7 other patients (age 36-65, average 51.0 years). One biopsy specimen was obtained from each portion. RESULTS: Twelve of the eighteen biopsy specimens from the ulcer margin, 6 of the 7 biopsy specimens from normal portions of the antrum and 3 of the 7 biopsy specimens from normal portions of the body showed CGRP-immunoreactive staining. Intense staining was more marked in the specimens from the ulcer margin compared to those of the normal portions. CONCLUSIONS: CGRP immunoreactivity was observed in the human gastric mucosa in considerable abundance, and it is presumed that CGRP might participate in a restoration mechanism of the ulcer.

Adult↗

PubMedDate not supplied

Gene transfer with cationic lipid into human hepatocellular carcinoma in nude mice.

BACKGROUND/AIMS: Using a cationic lipid, gene transfection into the tumor of a human hepatocellular carcinoma model in nude mice was attempted in order to explore the possibility of its use in gene therapy. METHODOLOGY: A DNA-lipid complex was made by combining the cationic lipid distearyldimethyl ammonium bromide (DDAB) with pCMV sPORT expressing the reporter gene LacZ. The expression of this complex was first investigated in vitro against the human hepatocellular carcinoma cell line Li7HM. It was then injected directly into a hepatocellular carcinoma model tumor created by implanting Li7HM into the liver of BALB/c nu/nu mice, and the expression of LacZ was histologically evaluated. RESULTS: LacZ gene was expressed in Li7HM in vitro with the optimized DNA-lipid complex. Cell toxicity was not a problem. Expression of LacZ was also seen in the mouse hepatocellular model tumor into which the complex had been injected, indicating successful gene transfection with this method. CONCLUSIONS: Direct injection of a DNA-lipid complex into a mouse hepatocellular carcinoma model tumor is a safe and simple method of gene transfection, proving this to be a viable method of transfer for use in gene therapy.

Animals↗

PubMedDate not supplied

The effect of intraportal administration of prostaglandin E1 on liver blood flow and liver function.

BACKGROUND/AIMS: Prostaglandin E1 (PGE1) exerts a hepatic cytoprotective action directly and indirectly through enhancing hepatic blood flow. Although PGE1 is usually administered systemically, more than 60% of PGE1 is inactivated during only a single passage through the lung. By administering PGE1 intraportally the intrahepatic level of this drug can be increased effectively and liver dysfunction might be prevented. In this study, the effect of intraportal administration of PGE1 to patients who underwent hepatectomy was estimated. METHODOLOGY: Twenty patients who underwent hepatectomy from January 1995 to December 1996 were divided into 2 groups, i.e., a PGE1 group (n=8) and a control group (n=12). Laboratory data and hepatic portal blood flow were examined before and after hepatectomy. In the PGE 1 group, PGE 1 was continuously infused at a dose of 120 microg/day for 5 days through a catheter inserted into the portal vein via the gastroepiploic vein. RESULTS: There was no difference in the post-operative change in aspartate aminotransferase (AST) or alanine aminotransferase (ALT) between the 2 groups. Elevation of total bilirubin was more significantly suppressed in the PG group than in the control group. Total branched-chain amino acids and the tyrosine ratio reached their peak on the 5th post-operative day (POD) and were significantly higher in the PG group. Post-operative portal blood flow was significantly increased in the PG group. CONCLUSIONS: Our results indicated that continuous intraportal administration of small doses of PGE1 is effective for the protection of hepatic function after hepatectomy.

Adult↗