Neonatal erythema infectiosum

A report is presented of a patient with neonatal erythema infectiosum who developed petechiae, transient thrombocytopenia and transient cardiac failure due to transplacental transmission of human parvovirus B19 (HPV B19) infection. It is suggested that the thrombocytopenia was caused by platelet-associated IgG produced by the patient, and that the cardiac failure may have been caused by direct entry of HPV B19 into the cardiac tissue.     

Enhanced levels of C-X-C chemokine,human GROα, in Helicobacter pylori-associated gastric disease*

C-X-C Chemokines play an important role for neutrophil extravasation through microvessels. Although the level of interleukin (IL)-8 is known to increase in the Helicobacter pylori-infected gastric mucosa, another C-X-C chemokine, GROα, has not been evaluated in the H. pylori-associated gastric mucosal injury. The present study was designed to investigate gastric contents of GROα in relation to those of IL-8 in the gastric mucosa of H. pylori-infected peptic ulcer patients. Thirty-eight patients with gastric ulcer and 41 with gastritis underwent endoscopy with informed consent and 49 were found to be H. pylori positive and 30 H. pylori negative. Biopsies from the gastric corpus were performed in each patient to examine the H. pylori colonization by bacterial culture, the rapid urease test and histological specimens as well as measurement of the contents of human GROα and IL-8. Helicobacter pylori infection was eradicated in 21 patients by triple therapy (lansoprazole 30mg, amoxycillin 2.0g, clarithromycin 600 mg; 2 weeks). The samples for GROα and IL-8 assay were homogenized in 0.02% aprotinin containing phosphate-buffered solution and the mucosal contents of GROα and IL-8 in the supernatants were quantified by sandwich enzyme immunoassay methods. The levels of GROα and IL-8 in H. pylori-positive gastric mucosa were significantly higher than those in the H. pylori-negative mucosa. There was a significant linear correlation between the levels of GROα and IL-8 (r= 0.798, P < 0.01). After the eradication of H. pylori by the triple therapy, the levels of GROα and IL-8 were significantly decreased. The GROα showed an increase in the H. pylori-positive gastric mucosa in a similar fashion as IL-8 contents, suggesting a pathogenetic role for GROα in H. pylori-associated gastric mucosal injury.     

Sulfhydryl blocker-induced colitis in the rat: Immunological changes in thymus gland and colonic mucosa

The study was designed to examine the changes of thymus in sulfhydryl blocker-induced colitis. We used N-ethylmaleimide (NEM) as sulfhydryl blockers. Fasted male Sprague-Dawley rats were given 3% NEM in 1% methyl cellulose into the colon. N-ethylmaleimide treatment caused severe diarrhoea with bleeding for the first 7 days. At autopsy, adhesions, colon dilatation, and single or multiple erosions and ulcers were observed. Time-course studies revealed that the lesions were most extensive and severe 3 or 7 days after the administration of NEM. Histological examination of colon on the 3rd day after NEM treatment demonstrated mucosal erosion, oedema and extensive infiltration of neutrophils. The mucosal lesions extended into the submucosa and muscle on the 7th day after NEM treatment. Immunohistochemical studies showed that T cells and macrophages were markedly increased in the lamina propria of colonic mucosa. After 3 weeks, the infiltration of chronic inflammatory cells was observed and regeneration of the mucosa was noticed. The thymus gland was significantly decreased in weight and size on the 3rd day after NEM treatment, but the weight loss of thymus gland was regained in 3 weeks. Transient atrophy of thymus gland was noticed in this colitis model. The phenotypes of thymocytes were not influenced by NEM treatment. It is concluded that the thymus abnormalities in human ulcerative colitis are not induced in this animal model and that other chronic models are necessary for the elucidation of the immunological abnormalities, including thymus abnormalities.     

Effects of recombinant tumour necrosis factor on antibody-dependent eosinophil-mediated damage to Schistosoma japonicum larvae

Human recombinant tumour necrosis factor (rTNF) enhanced monoclonal IgE-dependent eosinophil-mediated cytotoxicity to schistosomula of Schistosoma japonicum in a dose-dependent manner. The enhancing effect of rTNF was also observed for the antibody-dependent cytotoxicity of a human eosinophilic leukemia cell line, EoL-3, but not of another cell line, EoL-1. Observation by a slow-motion movie camera demonstrated that activated EoL-3 cells adhered to the surface of schistosomula by 6 h after incubation, which triggered intracellular movement of eosinophil granules. The granules were concentrated toward the surface of the larvae and then degranulation started. The cell membrane was left as a balloon-like remnant. Cell sorting analysis by FACStar indicated that the expression of receptors for C3bi (CR3) and low affinity FcR for IgE (Fc epsilon RII) increased on the surface of EoL-3 cells after stimulation with rTNF, while this was not observed for EoL-1 cells.     

Pneumomediastinum in newborns induced by the Elder CPR/demand valve during resuscitation

Two term and one post-term newborn infants with pneumomediastinum associated with the use of an Elder CPR (cardiopulmonary resuscitation)/demand valve during resuscitation are described. Because of apnea or irregular gasping respiration after vaginal delivery, they received repetitive positive-pressure ventilation with this resuscitator, which is designed to provide 100% oxygen with a limited pressure of up to 40 cmH₂O. Following resuscitation, the infants had tachypnea and diminished breath sounds. Roentgenograms and computed tomography of the chest revealed pneumomediastinum in all three and cervical subcutaneous emphysema in one. They required 25–30% oxygen for 3–14 days until they recovered spontaneously. Thus, pressures as low as 40 cmH₂O can cause barotrauma, and the Elder resuscitator, even when functioning properly, may injure the lungs of newborn infants.     

Gastrointestinal motility and the brain‐gut axis

The role of the brain‐gut axis in gastrointestinal motility is discussed according to the specific organs of the gastrointestinal tract. Not only clinical studies but basic animal research are reviewed. Although the mechanism of functional gut disorders remains to be clarified, recent data suggest that there is evidence that the brain‐gut axis has significant effects on gastrointestinal motility. The major role of endoscopy in the diagnosis of functional gastrointestinal disorders is to exclude organic gastrointestinal disorders. In the esophagus, the lower esophageal sphincter and a gamma‐aminobutyric acid B mechanism are considered to play important roles in gastroesophageal reflux disease. In the stomach, corticotropin‐releasing factor, neuropeptide Y and other substances might be involved in the pathogenesis of non‐ulcer dyspepsia. In the small intestine, corticotropin‐releasing factor, gamma‐aminobutyric acid B and other substances are considered to modulate intestinal transit via central mechanisms. In the colon, it is known that psychiatric factors are related to the onset and clinical course of irritable bowel syndrome. Serotonin, corticotropin‐releasing factor, gamma‐aminobutyric acid, orphanin FQ and neuropeptide Y have been reported as putative neurotransmitters. More efforts in basic science studies and animal and human studies of physiology of the gastointestinal tract are still required. These efforts will elucidate further mechanisms to clarify the etiology of motility disorders and encourage the investigation of new therapies in this field.