Gill structural change in response to turbidity has no effect on the oxygen uptake of a juvenile sparid fish.

Turbidity as a result of increased suspended sediments in coastal waters is an environmental stress of worldwide concern. Recent research on fish suggests that detrimental changes to gill structure can occur in turbid waters, with speculation that these alterations diminish fitness variables, such as growth and development, by negatively impacting the O2 uptake capacity (respiration) of fish. Specifically to address this unknown, the impact of turbid water on the gill structure, somatic growth rate and O2 uptake rates of a juvenile sparid species (Pagrus auratus) was addressed following exposure to five different turbidity treatments (<10, 20, 40, 60 or 80 nephelometric turbidity units) for 30 days. Significant gill structural change was apparent with a progressive increase in turbidity and was quantified as a reduction in lamellar density, as well as an increase in basal hyperplasia, epithelial lifting and increased oxygen diffusion distance across the lamellae. The weight of control fish did not change throughout the experiment, but all fish exposed to turbid waters lost weight, and weight loss increased with nephelometric turbidity units, confirming that long-term turbidity exposure is detrimental to growth productivity. The growth of fish could be impacted in a variety of ways, but the specific hypothesis that structural alteration of the gills impairs O2 uptake across the gills and limits growth fitness was not supported because there was no measurable difference in the standard metabolic rate, maximal metabolic rate, aerobic metabolic scope or critical oxygen saturation limit of fish measured in clear water after 30 days of exposure. Although impaired O2 uptake as a result of structurally adjusted gills is unlikely to be the cause of poor fish growth, the exact mechanism by which growth productivity is affected in turbid conditions remains unclear and warrants further investigation.

Enterovirus-specific IgM in the diagnosis of meningitis.

Samples of serum from 557 patients with a clinical diagnosis of meningitis or encephalitis and referred to the Epsom Public Health Laboratory during a period of 3 years were tested for enterovirus-specific IgM in a mu capture enzyme-linked immunosorbent assay (ELISA). Enterovirus-specific IgM was detected in 45% samples from all age groups. In the 3-5-year age group, 67% specimens were positive. A notable male predominance (73%) was seen in the age group 0-15 years. As predicted, a seasonal increase in incidence was found in the summer and autumn months. Data from a questionnaire sent to the referring laboratories showed only a 5% enterovirus isolation rate from cerebrospinal fluids when isolation of a virus was attempted. The enterovirus IgM ELISA is a sensitive economical and rapid method for use in the diagnosis of viral meningitis.

Coxsackie viruses and diabetes mellitus.

Serum specimens from 162 patients with insulin-dependent diabetes of recent onset and 319 controls were tested for neutralizing antibodies to Coxsackie viruses types B1 to B5. Antibody to type B4 virus was more often found in diabetics than in controls, particularly in the 10-19 year age group. Though controls were not matched for geographical area it was thought that this was unlikely to explain the difference found. The month of onset of diabetes in the patients studied showed a pronounced seasonal incidence, which resembled that found in earlier studies.