Hyperplastic vascular smooth muscle cells of the intrarenal arteries in angiotensin II type 1a receptor null mutant mice

BACKGROUND: Angiotensin II (Ang II), which contracts vascular smooth muscle cells (VSMCs), has been reported to regulate VSMC growth. Recently formed transgenic mice without angiotensinogen or Ang II receptors showed vascular alterations. However, it is still unclear how their VSMCs alter. We explored the role of Ang II via the Ang II type 1a receptor (AT1a) in VSMCs in vivo using AT1a null mutant mice. METHODS: We analyzed the ultrastructure of the intrarenal arteries in AT1a null mutant mice that were homozygous for a targeted disruption of AT1a receptor gene using light and electron microscopy. RESULTS: The structural changes of the intrarenal arteries in AT1a null mutant mice showed the wall thickening, which in the interlobar, arcuate, and proximal interlobular arteries consisted of two additional populations of VSMCs, on the luminal and abluminal sides of the media. The luminal overpopulation of smooth muscle cells (SMCs) was arranged in a longitudinal direction separated by increased interposed elastic laminae. The abluminal overpopulation of SMCs ran in circumferential directions separated from the main population. The cytological structure of VSMCs in AT1a null mutant mice was smaller in size, contained more organelles for protein synthesis and secretion than in control mice, and had poorly developed contractile apparatus. CONCLUSIONS: The lack of AT1a signaling causes structural abnormalities in the renal vascular system and transforms the phenotype of VSMCs into cell proliferation, induces the escape of VSMCs from the circular mechanical integrity, and results in increased synthesis of extracellular matrices.     

Competitive incorporation of arachidonic acid analogs by cultured rat keratinocytes

Arachidonic acid (20:4 n-6) and its metabolic products, such as prostaglandins and leukotrienes, have been known to be associated with skin inflammatory reactions. However, the mechanism of the competitive incorporation of 20:4 n-6 into keratinocytes among polyunsaturated fatty acids (PUFAs) remains uncertain. To investigate the relationship between the molecular structure of PUFAs and the rate of incorporation of PUFAs into cells, a fetal rat skin keratinocyte (FRSK) cell line was used. The cells were incubated for 24 h with any two of the following arachidonic acid analogs: mead acid (20:3 n-9), dihomo-gamma-linolenic acid (20:3 n-6), 11,14,17-cis-eicosatrienoic acid (20:3 n-3), arachidonic acid (20:4 n-6), eicosapentaenoic acid (20:5 n-3) and 5,8,11,14-cis-nonadecatetraenoic acid (19:4 n-5), at the ratio of 1:0, 0.5:0.5, or 0:1; and their incorporation into lipid was measured by capillary gas-liquid chromatography. The experiments indicated that 20:3 n-6 was preferentially incorporated into phospholipids of FRSK rather than 20:3 n-9 or 20:3 n-3, and 19:4 n-5 as well as 20:4 n-6 was preferentially incorporated into total cellular lipid and phospholipids rather than 20:3 n-9 or 20:5 n-3. When two PUFAs were added simultaneously to the medium, 19:4 n-5 most effectively reduced the competitive incorporation of 20:4 n-6 into phospholipids. These results suggest that keratinocytes discriminate 20:4 n-6 from other arachidonic acid analogs by its double bond positions from the carboxyl group.     

Environmental survey of salmonella and comparison of genotypic character with human isolates in Western Japan

To estimate the prevalence and distribution of salmonellae, especially Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis), in Western Japan, an investigation was conducted of the chicken industry and environmental sources between 1995 and 1998. Salmonellae were isolated from 34 of 90 samples (37.8%) of raw chicken parts, 34 of 98 faecal samples (34.7%) at 35 broiler farms, 11 of 59 samples (18.6%) of liquid eggs, and from 71 of 272 samples (26.1%) of swab specimens from equipment and cracked or faecally soiled shell eggs at the processing facilities. Salmonellae, including S. Enteritidis, were also isolated from swab samples of henhouses associated with one of the shell-egg processing facilities (11 samples out of 55, 20%). In the broiler meat production environment, S. Infantis was dominant. Twenty-two of 36 sewage samples (61.1%) and 16 of 72 samples (22.2%) taken from 5 rivers contained salmonellae including S. Enteritidis. S. Enteritidis isolates were analysed with pulsed-field gel electrophoresis using enzyme Bln I. Thirty-four isolates from shell-egg processing facilities and henhouses, obtained over several years, had the same pulsed-field profile as isolates obtained from four individual outbreaks that occurred in this location in 1997. One of the clonal lines of S. Enteritidis, among multiple serovars of salmonellae in the environment, was thought to have distributed in reservoirs, laying hens, for several years, and continued to cause outbreaks in this area.     

Induction of endometrial cycles and ovulation in a woman with combined 17alpha-hydroxylase/17,20-lyase deficiency due to compound heterozygous mutations on the p45017alpha gene

OBJECTIVE: To describe the case of a Japanese woman with combined 17alpha-hydroxylase/17,20-lyase deficiency (congenital adrenal hyperplasia type V) and to discuss possible therapeutic procedures in such patients. DESIGN: Case report. SETTING: University hospital. PATIENT(s): A 26-year-old woman with secondary amenorrhea and primary sterility. INTERVENTION(s): Nucleotide sequencing of the P45017alpha gene (CYP17), induction of endometrial maturation with steroid hormone replacement, and ovulation induction with gonadotropin. MAIN OUTCOME MEASURE(s): Nucleotide sequence of CYP17, endometrial thickness and follicle diameter measured by transvaginal ultrasonography, and histologic evaluation of the endometrium. RESULT(s): Two different mutations were detected on CYP17: One was a deletion of the phenylalanine codon (TTC) at either amino acid 53 or 54 in exon 1, and the other was a missense mutation with the substitution of histidine (CAC) by leucine (CTC) at position 373 in exon 6. Repeated histologic evaluations performed during treatment with P consistently revealed an unripe endometrium with glands of the early secretory phase and markedly scanty stroma. Ultrasound examination revealed follicular growth and ovulation after gonadotropin administration, but insufficient thickness of the endometrium. CONCLUSION(s): Ovulation induction was possible in this patient with 17alpha-hydroxylase/17,20-lyase deficiency, but the endometrial response to steroid hormone replacement was extremely poor.     

Multislice CT of the thorax: effects of contrast material pushed with saline solution using a dual power injector on contrast material dose and perivenous artifacts

A new method of power injection of contrast material flushed with saline solution for thoracic multislice CT using a dual power injector was evaluated in 105 patients. The patients were categorized into 3 groups of 35 patients each, according to the protocol of contrast material administration: (1) 100 mL of non-ionic contrast material(300 mgI/mL), (2) 75 mL of the same contrast material, and (3) 75 mL of the same contrast material flushed with 30 mL of saline solution. Scanning was performed in a caudal-to-cranial direction. Mean attenuation for the three protocols was measured in the superior vena cava, pulmonary trunk, ascending aorta, and descending aorta. Vascular opacification and perivenous artifacts were graded using four-point scoring by a consensus panel of three blinded radiologists. Intravenous injection of 75 mL of contrast material flushed with saline solution provided significantly better vascular opacification in the superior vena cava(p < 0.001) and pulmonary trunk(p < 0.02) than that provided by a 75 mL or 100 mL injection of contrast material alone. A similar degree of enhancement was observed in the ascending and descending aorta. Further, perivenous artifacts in the subclavian vein were significantly reduced (p < 0.05).     

Value of upper gastrointestinal endoscopic examination of head and neck cancer patients

Between January 1995 and March 1999, we performed the upper gastrointestinal endoscopic examinations on 287 patients with head and neck cancers and detected 23 cases (8%) of esophageal cancer and 8 cases (2.8%) of gastric cancer, showing how frequently esophageal cancer occurs in head and neck cancer. The esophageal cancer involved the oral cavity in 8 cases (9.5%), the oropharynx in 3 cases (8.6%), the hypopharynx in 10 cases (19.6%), and the larynx in 2 cases (2%). Esophageal cancer occurred most frequently in hypopharyngeal cancer, particularly the pyriform sinus type and the postcricoid type. We conclude that upper gastrointestinal endoscopic examination, including Lugol staining, is necessary in head and neck cancer patients.     

Roles of chemokines and chemokine receptors in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) uses a coreceptor together with CD4 to enter CD4+ target cells. The chemokine receptors CXCR4 and CCR5 have been found to be the major coreceptors for T-cell line-tropic and macrophage-tropic HIV-1 strains, respectively, although many other chemokine and orphan receptors have also been identified as potential coreceptors for HIV-1. Genetic analyses has revealed the importance of chemokine and chemokine receptor genes in disease progression. The discovery of coreceptors provides a more defined scheme for virus entry in which the HIV-1 envelope glycoprotein sequentially binds CD4 and coreceptor, leading to a membrane fusion reaction between the viral envelope and the plasma membrane of the target cell. It also provides the basis for HIV-1 cell tropism. The identification of HIV coreceptors provides new opportunities for the development of anti-HIV therapy. Many coreceptor-based therapeutic approaches have been developed, some of which are currently in clinical trials.     

Primary nonsecretory plasma cell leukemia: a rare variant of multiple myeloma

 We report a patient with primary nonsecretory plasma cell leukemia. These cells resembled prolymphocytes and expressed only CD38 and CD56. Due to the atypical morphology and lack of monoclonal immunoglobulins in both serum and urine, it was difficult to make a correct diagnosis. Electron-microscopic and immunocytochemical cytoplasmic studies were useful. Received: May 4, 1998 / Accepted: September 3, 1998