Intensified IgA mesangial deposits after administration of sheep anti-type IV collagen serum in mice

Sheep anti-type IV collagen serum was intravenously administered to male mice of the BALB/c, C3H and ddY strains, and their kidneys were morphologically studied monthly for 10 months thereafter. By immunofluorescence, the sheep IgG was seen to have immediately become conjugated to the glomeruli, mainly in a mesangial pattern. Successively, autologous mouse C3 and IgG appeared with the same type of distribution. Within 3 to 4 months after the start of the experiment, mouse IgA also appeared in the mesangium, especially in ddY mice. The intensity and frequency of mesangial IgA deposition and the serum IgA level increased with time in this strain. BALB/c and C3H mice also showed the same tendency of mesangial IgA deposition, although to a lesser degree. In summary, it was concluded that mesangial IgA deposition was due to non-immunological local trapping, on the basis of the results obtained by ELISA analysis of the sera and renal eluate. Although the ddY mouse is known to show spontaneous mesangial IgA deposition associated with a high serum IgA level with aging, these characteristics were much accelerated and intensified by this antiserum treatment. The relation of this observation to the pathogenesis of human IgA nephritis is discussed.     

Epitopic heterogeneity of the CD36 antigen expressed by normal and neoplastic endothelial cells. An immunohistochemical study with a novel monoclonal antibody 8C9.

Phenotypic and functional heterogeneity of endothelial cells (ECs) is being recognized with increasing frequency. Here we report a novel murine monoclonal antibody (MoAb), named 8C9, that detects a unique epitope on the leukocyte differentiation antigen CD36 (platelet glycoprotein IV or IIIb) expressed by both normal and neoplastic ECs. In immunohistochemical and flow-cytometric studies, 8C9-immunoreactivity was detected on capillary ECs, adipocytes, monocytes, platelets and a human monocytoid cell line U-937, which are known to express the CD36 antigen. Blocking experiments using U-937 cells and studies on cryostat sections revealed that a murine MoAb OKM5, which detects the CD36 antigen, blocked the binding of 8C9 to its antigen. Immunoblot analysis showed that 8C9 bound to a 97-kDa membrane protein expressed by U-937 cells treated with phorbol ester. These results indicate that 8C9 detects the CD36 antigen. However, the findings that some OKM5-positive normal ECs in the liver, spleen and lymph nodes as well as neoplastic ECs in a cutaneous angiosarcoma did not react with 8C9, together with the fact that the CD36 antigen does not form a complex or associate with other proteins, suggest epitopic heterogeneity of the CD36 antigen expressed by these tissues.     

The organization of serotonin fibers in the anterior column of the mammalian spinal cord. An immunohistochemical study

Detailed comparative analysis of the organization of serotonin fibers in the anterior column of the mammalian spinal cord (rat, guinea pig, cat, dog and monkey) was carried out by use of the indirect antibody peroxidase-antiperoxidase (PAP) method. The plexus formation of serotonin-containing varicose fibers around the alpha-motoneurons in the monkey anterior horn was in much closer apposition to the cell bodies in comparison with the spinal cords of the rodents and carnivores. The results may suggest that anterior horn motoneurons in the simian spinal cord are intimately innervated by serotonin fibers in a manner different from that of rodents and carnivores. Furthermore, the small cell groups endowed with particularly dense networks of serotonin fibers were demonstrable in the anterior horn of L1-L2 segments of rats, and L3-L4 of guinea pigs and monkeys; however, in the lumbar levels of the carnivores this was not the case. Hence it seems doubtless that there exists in the lumbar anterior horn of the rodent and primate spinal cords a cell group with an unknown specialized function.     

Neurofibroma of the gallbladder seen as a papillary polyp

A case of neurofibroma of the gallbladder in a 44-year-old woman without von Recklinghausen neurofibromatosis but with right hypochondralgia is reported. The tumor was seen preoperatively as a polypoid lesion and in the resected gallbladder as a papillary polypoid growth over the main intramural tumor mass. Microscopically, the tumor was identified as a neurofibroma with many tactile corpuscle-like structures (Wagner-Meissner bodies), which were found by electron microscopic and immunohistochemical examination to consist of Schwann cells. Twelve cases of non-epithelial neoplasms arising in the gallbladder are also reviewed.     

Deproteinizing effects on resin-tooth bond structures

This study investigated the effects of NaOCl on resin-tooth bonds to simulate the situations of long-term durability and caries invasion. Resin-tooth bonded specimens were produced with the use of two resin adhesives (Excite and One-Bond). Resin-tooth bonded beams (adhesive area; 0.9 mm2) were serially sectioned and the specimens were immersed in 10% NaOCl medium for 0 (control), 2, 4, and 6 h after being stored in water for 24 h. After immersion, microtensile bond tests were performed. SEM fractography was conducted to calculate each failure mode by image analysis. In addition, the adhesive interface was examined with the use of TEM. In the control specimens, enamel bond strengths had no difference between Excite (45.6 +/- 15.0) and One-Bond (56.9 +/- 12.9). On the other hand, dentin bond strengths had significant difference between Excite (80.6 +/- 21.2) and One-Bond (50.7 +/- 11.2). The bond strengths decreased with increased storage time for both systems with enamel and dentin bonds. The deteriorated mineralized dentin of beams resulted in bond-strength reduction for resin-enamel bonds. For dentin bonding, the adhesive interface was gradually dissolved from the outer to the center portion of the beam. The depletion of collagen fibrils within the demineralized dentin or hybrid layer deformation was found under SEM and TEM examinations. These morphological changes are responsible for bond strength reduction of resin-dentin bonds.     

Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression

Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4±1.8 weeks, mean birth weight 1047±249 g) was 230±71×10⁹/l just after birth and thereafter gradually increased to 579±178×10⁹/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2–6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants.     

Treatable ischemic neuronal damage in the gerbil hippocampus

The Mongolian gerbil is known to develop delayed neuronal death in the hippocampus following brief forebrain ischemia (Brain Res 239: 57-69). Morphological, biochemical, or electrophysiological studies on this neuronal injury have shown that neurons still retain potential reversibility at the earlier period of alteration. To examine this possibility, immediately following 5 min of ischemia in the gerbil, pentobarbital, diazepam, or nizofenone was injected. Seven days following ischemic insult, animals were perfusion fixed and neuronal density in the hippocampal CA1 subfield was counted. Most of the neurons in the CA1 sector survived ischemic insult when a drug was given, whereas most of them were lost without the treatment. The average neuronal density of treated groups showed a statistically significant (p less than 0.01) persistence compared with that of control group. The effective dosage of the drugs were 20-40 mg/kg in pentobarbital, 10-20 mg/kg in diazepam, and 12.5-25 mg/kg in nizofenone. On the other hand, when pentobarbital was injected 1 hr following ischemia, while neurons still remain intact morphologically, it showed no effect. This result indicates that the neuronal damage of "delayed neuronal death" type is reversible if treatment is instituted at an early period of cell change.     

HIV misconceptions among married women in Malawi: the role of household decision-making autonomy

Journal of Public Health - Married women face one of the highest HIV rates in Malawi. Although HIV misconceptions have been identified as a major contributor to HIV infection, we know very little...