Responsiveness of the ANP providing system to volume load in conscious dogs

We examined in detail changes in arterial plasma ANP concentration in response to volume load in conscious dogs. In a 5-min volume load experiment, 18 ml/kg of isosmotic and isooncotic 3% Dextran 40 in saline was infused over a period of 5 min. Mean left atrial pressure (MLAP) increased transiently by 7.6±0.9 mm Hg. Plasma ANP level (P-ANP) did not significantly increase. Assayed P-ANP levels were corrected for hemodilution. Corrected P-ANP (C-ANP) significantly increased from 206±17 to 348±34 pg/ml. However, the level of C-ANP did not reach a steady state. No significant linear correlation was found between increases in MLAP and normalized C-ANP. In a 45-min volume load experiment, the elevated level of MLAP caused by the 5-min volume load was maintained for 40 min by supplemental infusion. C-ANP significantly increased from 196±18 pg/ml to 435±73 ng/ml. The level of C-ANP reached a steady state. A close linear correlation was observed between increases in MLAP and normalized C-ANP. However, the peak time of C-ANP lagged 10 min behind MLAP. These results indicate that it takes 10 min for P-ANP to reach a steady state in fully responding to a volume load, and that the long-term volume load is a prerequisite to the response of the ANP providing system.     

Seasonal changes in the hypothalamo-pituitary-testes axis of the Japanese wood mouse (Apodemus speciosus)

Seasonal changes in the hypothalamo-pituitary-testes axis of the Japanese wood mice (Apodemus speciosus) were studied. The testes, epididymis, pituitary and hypothalamus were compared between mice in the breeding season (July) and non-breeding season (October) using morphological techniques, and the plasma testosterone level was evaluated by enzyme immunoassay. Significant differences in these tissues were observed between the breeding season and the non-breeding season. Specifically, differences in the non-breeding season included 1) a decline in testicular and epididymal weights, arrest of spermatogenesis and decrease of serum testosterone concentration; 2) a decrease in the number of luteinizing hormone (LH)-, follicle stimulating hormone (FSH)-, prolactin (PRL)-, and growth hormone (GH)-immunoreactive cells, and decrease in the size of FSH, PRL, and GH-immunoreactive cells; and 3) an increase in the size of gonadotropin-releasing hormone (GnRH)-immunoreactive neurons. Our findings indicate that the male adult Japanese wood mouse exhibits unique seasonal changes in the hypothalamo-pituitary-testes axis which are not found in laboratory mice.     

Non-IgG1 nature of cutaneous basophil hypersensitivity factor in contact sensitivity. II. Demonstration of antigen-dependent basophil chemotactic activity of cutaneous basophil hypersensitivity factor

It was recently demonstrated that there was a specific activity to induce basophil-rich skin reaction in the sera of contact-sensitized guinea pigs (CBH factor, CBH-F). In the in vitro chemotactic assay system, CBH-F was shown to have weak basophil chemotactic activity but enhanced its activity in the presence of corresponding antigen(s). Furthermore, basophil chemotaxis in reaction to the antigen(s) was observed when the cells were preincubated with CBH-F. It worked mainly for Percoll-separated bone marrow basophils but not for oil-induced peritoneal macrophages. Immunological analysis revealed that CBH-F was a protein with a small molecular weight (MW 4-6 X 10(4] with an antigen binding site and isoelectric point of between 4.5 and 5.0. It did not show any characteristics of IgG1 or IgG2 on immunoadsorbent column and immunoelectrophoresis. Enzyme treatment with insoluble trypsin eliminated the chemotactic activity but this was not the case with neuraminidase treatment.     

A single gene controls resistance to Japanese encephalitis virus in mice

Summary The inheritance of resistance to Japanese encephalitis virus (JEV) was investigated using inbred strains of mice to study genetic resistance against JEV infection. C57BL/6 mice immunized intraperitoneally (i.p.) with an infective dose of JEV were resistant to intracerebral (i.c.) challenge with JEV, whereas most C3H/He mice treated in the same manner died. C57BL/6 mice developed this resistance 2 weeks earlier than C3H/He after intraperitoneal (i.p.) immunization. Passive transfer of spleen cells from immunized C57BL/6 protected the recipient mice from i.c. challenge, while transfer from immunized C3H/He was less effective. Since immunized athymic nude mice were not resistant to i.c. challenge with JEV, T lymphocytes were considered to be necessary for protection. When F₁, F₂ and backcross mice derived from C57BL/6 and C3H/He were challenged i.c. with JEV after i.p. immunizations, the number of resistant and susceptible mice were consistent with Mendelian ratios. Thus it can be concluded that resistance to JEV in mice was controlled by a single, dominant autosomal gene which was not linked toa (non agouti)-locus (chromosome 2).     

Two cases of intussusception of appendiceal mucocele: diagnostic value of preoperative ultrasonography

Mucocele of the appendix was first described and named "Hydrops processus vermiformis" by Rokitansky in 1866. Intussusception of a appendiceal mucocele is very rare and we have been able to find only 14 previously reported cases. We present two cases with preoperative ultrasonography which is valuable for its diagnosis. Case 1: A 5-year-old male was admitted to Kahoku Hospital because of right lateral colic abdominal pain and tumor. Ba-enema examination revealed intussusception to the colon and ultrasonography showed the cystic mass of the appendix. Case 2: A 51-year-old female was admitted because of right lower abdominal pain. Ultrasonography was helpful showing the cystic tumor at the base of the appendix. Recent reports say that ultrasonography is valuable examination for its diagnosis. Also in our two cases preoperative ultrasonography was performed and gave us valid information for its qualitative diagnosis.     

The Influence of Dysphagia on Nutritional and Frailty Status among Community-Dwelling Older Adults

Malnutrition is a core symptom of the frailty cycle in older adults. The purpose of this study was to investigate whether dysphagia influences nutrition or frailty status in community-dwelling older adults. The study participants were 320 Japanese community-dwelling older adults aged ≥65 years. All participants completed a questionnaire survey that included items on age, sex, family structure, self-rated health, nutritional and frailty status, and swallowing function. Nutritional status was categorized as malnourished, at risk of malnutrition, and well-nourished based on the Mini Nutrition Assessment-Short Form. The participants were then classified into a malnutrition (malnourished/at risk) or a well-nourished group (well-nourished). Frailty was assessed using the Cardiovascular Health Study criteria. The participants were then divided into a frailty (frail/pre-frail) or a non-frailty group (robust). Dysphagia was screened using the 10-item Eating Assessment Tool. Multiple logistic regression analysis was conducted to determine whether dysphagia was associated with nutritional or frailty status. The results revealed that dysphagia influenced both nutrition (odds ratio [OR]: 4.0; 95% confidence interval [CI]: 1.9–8.2) and frailty status (OR: 2.3; 95% CI: 1.0–5.2); therefore, the swallowing function would be an important factor for community-dwelling older adults on frailty prevention programs.