Monoclonal Antibodies to Trypanosoma cruzi Inhibit Motility and Nucleic Acid Synthesis of Culture Forms

Monoclonal antibodies were raised against the surface of epimastigotes and metacylic trypomastigotes of Trypanosoma cruzi, as shown by electron microscopy, agglutination, and immunofluorescence. The antibodies were stage specific but not strain specific. A deleterious effect of the antibodies on T. cruzi culture forms was shown by the drastic reduction of parasite motility and incorporation of nucleic acid precursors. Some fraction of the parasite population, however, was viable and replicated and infected mouse macrophages in culture. The antibodies were found to also mediate complement-induced lysis of culture forms of T. cruzi.     

Malaria infection induces rapid elevation of the soluble Fas ligand level in serum and subsequent T lymphocytopenia: possible factors responsible for the differences in susceptibility of two species of Macaca monkeys to Plasmodium coatneyi infection

The intraerythrocytic stage of the simian malaria parasite Plasmodium coatneyi (CDC strain) was intravenously inoculated into two species of macaques with different susceptibilities to infection with this parasite, including four Japanese macaques (Macaca fuscata) and three cynomolgus macaques (M. fascicularis). The Japanese macaques infected with P. coatneyi developed severe clinical manifestations similar to those of severe human malaria and eventually became moribund, while the infected cynomolgus macaques, natural hosts of the parasite, exhibited no severe manifestation of disease except anemia and finally recovered from the infection. In the infected Japanese macaques, peripheral CD4(+) and CD8(+) T-cell populations were markedly decreased and fragmentation of chromosomal DNA in peripheral blood mononuclear cells was detected during the terminal period of infection, suggesting that apoptotic cell death was responsible at least in part for the T lymphocytopenia. Furthermore, soluble Fas ligand levels in sera of the infected Japanese macaques increased gradually to a markedly high level of 28. 83 +/- 10.56 pg/ml (n = 4) when the animals became moribund. On the other hand, none of the infected cynomolgus monkeys exhibited either T lymphocytopenia or elevated soluble Fas ligand level. These findings suggest that differences in immune response between the two species of macaque tested accounted for the contrasting outcomes after infection with the same isolate of malarial parasite, and in particular that a profound T lymphocytopenia due to Fas-derived apoptosis played a role in the fatal course of malaria in the infected Japanese macaques.     

Microfilamentous type VI collagen in the hyalinized stroma of the hypertrophied ligamentum flavum

Summary Thickened ligamenta flava obtained from 14 patients with spinal canal stenosis were examined with special reference to type VI collagen. The characteristic histological finding in the thickened area was rupture of normal elastic fibre meshwork with resultant fibrosis which usually appeared hyaline. Using an immunohistological method, collagen types VI, I and III were found to be present in the hyaline matrix. Ultrastructural study revealed many microfilamentous structures of type VI collagen admixed in loosely packed, banded collagen fibres. With differential salt precipitation of pepsin-extracted collagen the existence of type VI collagen was confirmed by SDS-polyacrylamide gel electrophoresis analysis and Western blotting analysis using anti-type VI collagen antibody. Quantification of type VI collagen in pepsin-extracted crude collagen samples by an inhibition enzyme-linked immunosorbent assay showed an increasing amount of type VI collagen in the thickened ligamenta flava compared to the normal ligaments. Thus, increase of type VI collagen is the main contribution to the thickening of the ligamentum flavum. This may represent an adaptational and reparative process associated with disruption of elastic fibres.     

Unusual Enterobacteriaceae: H2S+ Shigella sonnei, one authentic and one false positive due to contamination with the obligate anaerobe Eubacterium lentum.

A mixture of Shigella sonnei and Eubacterium lentum produced H2S in triple sugar iron agar; however, neither produced any in pure culture. A second culture of S. sonnei, isolated in Japan, is thought to be the first documented H2S+ Shigella.     

THE PRESENCE OF INTRACYTOPLASMIC CONFRONTING CISTERNAE OF THE ENDOPLASMIC RETICULUM IN OSTEOSARCOMA CELLS IN INTERPHASE

Confronting cisternae of the endoplasmic reticulum recognized in tumor cells of 7 cases of osteosarcoma were presented. They were found in the mitotic cells as well as in the cytoplasms of interphase cells. The more the mitotic cells were observed in 1 μm-thick sections, the more frequently those membranous structures were encountered in the corresponding ultrathin sections. In the interphase cells, such structures were located around Golgi apparatus or close to the nucleus. Occasionally, they were composed of a pair of closely apposed cisternae of the nuclear membrane and the rough endoplasmic reticulum. These results seem to indicate that the nuclear envelope which is disrupted and reformed during mitosis in rapidly proliferating cells takes part in the formation of the confronting cisternae of the endoplasmic reticulum.     

Novel missense mutations in the human lysosomal sialidase gene in sialidosis patients and prediction of structural alterations of mutant enzymes

Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S) in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type 2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S transversions cause large conformational changes including the active site residues responsible for binding the sialic acid carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of the constructed models, which was also influenced by previously identified V217M and G243R transversions. Received: Stptember 21, 2001 / Accepted: November 2, 2001     

Prevention of rotavirus infection by oral administration of cow colostrum containing antihumanrotavirus antibody

After immunizing 8-month pregnant Holstein cows with human rotavirus, Wa strain, cow colostrum containing neutralizing antibody to human rotavirus, designated as Rota colostrum, was obtained. After randomly grouping 13 infants from a single orphanage, 6 infants received 20 ml of Rota colostrum every morning and 7 control infants received 20 ml of market milk. One month later, rotavirus associated diarrhea was observed in 6 of the 7 infants given milk and 1 out of the 6 infants given Rota colostrum. Orally administered Rota colostrum significantly protected infants from diarrhea caused by rotavirus (P < 0.05). Two out of 5 Rota colostrum recipients who were free from diarrhea showed rises in complement fixation (CF) antibody titer after the rotavirus infection epidemic. Thus, Rota colostrum prevented the outbreak of diarrhea but did not prevent immunological responses to natural rotavirus infection. In the therapeutic trial Rota colostrum had no effect on duration of diarrhea, bowel movements or virus shedding in stool. However, there were no side-effects of Rota colostrum.     

Aqueductal lesions in 6-aminonicotinamide-treated suckling mice

Summary Suckling mice which received a single intraperitoneal injection of 6-aminonicotinamide on the 5th postnatal day, consistently developed hydrocephalus. During the early stages of hydrocephalus (7–9 days after injection), aqueductal lesions were characterized by edematous ependymal and subependymal cells, and spongy changes in the periaqueductal area, which resulted in aqueduct stenosis. Later stages (after 20 days post-injection) showed that these edematous changes totally subsided, leaving an obliterated aqueduct which was similar to that of human congenital hydrocephalus. At the completely obliterated area, ultrastructural investigation disclosed a normal-looking neuropil but no aqueductal lumen. In the remaining ependymal cell, increased intermediate filaments and lipid droplets occurred. These data suggest that acute ependymal cell degeneration during the perinatal period may result in the profile of aqueduct agenesis in human congenital hydrocephalus.Supported in part by research grants NS-03356, NS-10803 from NINCDS, USPHS     

Lessons learned from lower urinary tract complications of anorectoplasty for imperforate anus with rectourethral/rectovesical fistula: Laparoscopy-assisted versus posterior sagittal approaches

PurposeTo report the sequelae of and preventive strategies for selected lower urinary tract (LUT) complications, i.e., posterior urethral diverticulum (PUD), intraoperative LUT injuries, postoperative dysuria, and fistula recurrence in male imperforate anus (IA) with rectourethral/rectovesical (RU/RV) fistula after laparoscopy-assisted anorectoplasty (LAARP) or posterior sagittal anorectoplasty (PSARP).Methods153 boys with IA and RU/RV fistula treated 1986–2019 by LAARP (n = 56) or PSARP (n = 97) at two unrelated institutes were studied retrospectively.ResultsAfter mean follow-up of 17.0 years (range: 36.5 days-32.0 years), the overall incidences of LUT complications were: LAARP (6/56; 10.7%); PSARP (7/97; 7.2%); p = 0.55, comprising PUD: LAARP (n = 5), PSARP (n = 0); p = 0.006; injuries: LAARP (n = 0), PSARP (n = 5); p = 0.16; dysuria: LAARP (n = 1), PSARP (n = 1); p>0.999; and recurrence: LAARP (n = 0), PSARP (n = 1); p>0.999. Mean onset of PUD was 5.1 years (range: 1.0–15.1 years). Treatment: PUD: surgery (n = 2/5), conservative (n = 3/5); injuries: intraoperative repair (n = 5/5); dysuria: conservative (n = 2/2), and recurrence: redo PSARP (n = 1/1).ConclusionsStrategies devised to improve dissection accuracy resolved the specific technical issues causing LUT complications (remnant RU fistula dissection in LAARP and blind posterior access in PSARP). Currently, the incidence of new cases of PUD and LUT injuries is zero.Level of Evidence: Level III