Convalescent Group Research Articles

Group C Rotavirus Infections in Patients with Diarrhea in Thailand, Nepal, and England

Atypical rotavirus obtained from fecal specimens of six patients with diarrhea from Thailand, Nepal, and England were characterized by using polyacrylamide gel electrophoresis and immune electron microscopy. The electropherotypes were characteristic of the porcine reference group C rotavirus strain but demonstrated considerable strain-to-strain variation. Human convalescent group C sera had a high titer (1:320) when tested against the human isolates and a low titer (1:40) when tested against a porcine reference strain (Cowden). When porcine antiserum (Cowden) was tested against the human isolates, the titers ranged from 1:40 to 1:320, indicating significant antigenic diversity between strains. Group C rotavirus appears to have a worldwide distribution as an agent associated with diarrhea in children and adults.

Bacterial contamination of the small intestine of infants with enteropathogenic Escherichia coli and other enteric infections: a factor in the aetiology of persistent diarrhoea?

The duodenal microflora was studied during the first week of diarrhoea in 40 infants with acute infectious diarrhoea of different aetiologies and compared with that in a convalescent group and a group in whom diarrhoea of known aetiology had persisted for more than 14 days after an acute onset. In the acute phase 16 of the 40 infants had more than 10(4) colony forming bacteria/ml, predominantly upper respiratory commensals. In over half of the infants infected with enteropathogenic Escherichia coli a faecal type flora was found in the duodenum. This flora included the enteropathogenic E coli serotype isolated from the stool in three quarters of cases. Infants with persisting diarrhoea had significantly more faecal type bacteria in the duodenum than either those with acute diarrhoea or the convalescent group. In addition, there was a significant further increase in Enterobacteriaceae in infants whose persistent diarrhoea occurred after infection with enteropathogenic E coli. Infections with enteropathogenic E coli may have a predilection for disturbing the duodenal microflora, which may contribute to the development of persistent diarrhoea.

Interaction of Cytomegalovirus with Leukocytes from Patients with Mononucleosis Due to Cytomegalovirus

Cytomegalovirus (CMV) was isolated from hemic cells from seven of seven patients with acute CMV mononucleosis and from one of six patients with mononucleosis during convalescence. CMV was isolated from the mononuclear leukocyte fraction, the polymorphonuclear leukocyte fraction, or both cell fractions. Virus was not detected in washed erythrocytes, plasma, or leukocyte lysates. Mononuclear leukocytes from patients with acute CMV mononucleosis displayed an elevated level of incorporation of [3H]thymidine on the day of donation compared with that in cells from convalescent patients or normal donors. Responses to pokeweed mitogen and concanavalin A were significantly lower in patients with CMV mononucleosis than in normal donors. There were no significant differences among the acute, convalescent, and normal donor groups in response to phytohemagglutinin or in the one-way mixed leukocyte reaction. These findings suggest that in patients with CMV mononucleosis virus infects and may persist within peripheral blood leukocytes and that the lymphocytes of these patients are selectively hyporesponsive to certain mitogens.

Virus-induced pancreatic disease by Venezuelan encephalitis virus. Alterations in glucose tolerance and insulin release.

Viral infections have been implicated in the induction of diabetes mellitus in man and laboratory animals. Since virus-specific immunofluorescence (FA) is detectable in hamster pancreas during the acute phase of Venezuelan encephalitis (VE), experiments were designed to correlate pathologic and virologic events with metabolic studies in VE-infected hamsters. Golden Syrian hamsters were inoculated s.c. in groups of four to 12 with 100,000 plaque-forming units (PFU) of the vaccine strain (TC-83) of VE or 1,000 PFU of the virulent Trinidad strain of VE. Ultrastructurally, during Trinidad infection, mature virions were associated with the cell surfaces and within pancreatic beta cells in contrast to absence of virus-related changes in TC-83-infected hamsters. Virus-specific-FA was noted in islet cells and acinar cells of Trinidad-infected hamsters. VE growth curves demonstrated viral replication in pancreas with both strains. Although ultrastructural and FA changes were much more prominent in Trinidad-infected hamsters in contrast to TC-83-infected hamsters during the first few days of illness, the rapid lethality of the Trinidad-infected group necessitated performing all metabolic studies in TC-83-strain-infected hamsters. Accordingly, for the metabolic studies, glucose tolerance tests (GTT) using 2 mg. or 5 gm./kg. glucose i.p. were performed in groups of hamsters acutely infected two days earlier with the TC-83 vaccine strain and in 24-day and 90-day convalescent hamsters after TC-83 vaccine strain. Samples were obtained for glucose and immunoreactive insulin (IRI) determinations. Glucose intolerance occurred in hamsters in each of the infected groups given 5 gm./kg. glucose except for the 90-day convalescent TC-83 group. Severely decreased IRI responses occurred in the 24-day and 90-day convalescent TC-83 hamsters following both 2- and 5-gm./kg. glucose. Pancreatic IRI content in 24-day convalescent TC-83 hamsters was within normal limits, suggesting a defect in IRI release from the beta cells at this stage of convalescence.

Multiple sclerosis and cell-mediated hypersensitivity to myelin A 1 protein

Cellular hypersensitivity to myelin basic (A 1) protein was evaluated using the MIF assay in 246 subjects. Of 100 with multiple sclerosis positive results are seen in relationship to acute exacerbations of illness. Normal control subjects gave a mean value of 100 ± 9% whereas patients studied within 4 weeks of onset of illness gave a result of 59 ± 12.5%. A convalescent group studied between 5 and 12 weeks after an attack gave results of 86 ± 22.2%. A chronic group gave a mean of 91 ± 8.2%. Positive values were also seen in a number of other patients with central or peripheral nervous system disease especially those with “autoimmune disease”. However, results of this study clearly establish a temporal relationship between in vitro evidence of hypersensitivity to A 1 protein and clinical expression of disease.

Uric acid excretion in infectious mononucleosis: a function of increased purine turnover.

ABSTRACT Uric acid excretion was studied in patients with infectious mononucleosis during the acute and convalescent phases and in control groups of patients with nonspecific upper respiratory infections. Fifty-five percent of the patients with acute infectious mononucleosis had serum uric acids greater than 8.0 mg/100 ml. Urinary uric acid excretion and uric acid/creatinine ratios were significantly greater in the acute phase than in the convalescent or control groups, and draws attention to the possible development of uric acid nephropathy. The uric acid-creatinine ratio was greater than 0.60 in 80% of our patients and appears to be a suitable method for detecting increased purine turnover in infectious mononucleosis. This data supports the hypothesis that the hyperuricemia of infectious mononucleosis is due to increased purine turnover.