PubMed Health⌕ Search

Biomedical subjects

M Hatch

Publications and source records attributed to M Hatch.

10 recordsLinked to original sources
PubMed1992

Childhood leukemia around nuclear facilities.

Epidemiologic studies on the health effects of living near nuclear facilities have been rare and, indeed, radiobiological models would not predict any detectable increase in cancer risk to the general public from the very low levels of radioactivity emitted by nuclear installations. Thus the recent evidence suggesting an excess of childhood leukemias in the vicinity of certain nuclear sites in the United Kingdom has generated considerable controversy. To help resolve the uncertainty and enhance interpretability of results, future epidemiologic studies will need to be designed with great care (and within realistic cost limits). This commentary suggests three areas for methodologic consideration: (i) definition and modelling of radiation exposure; (ii) selection of cancer sites and sensitive subgroups; and (iii) use of incidence or mortality data. Specific suggestions for further epidemiologic research are offered as well.

Adolescent↗
PubMed1992

The epidemiology of electric and magnetic field exposures in the power frequency range and reproductive outcomes.

Some laboratory studies have reported effects of extremely low frequency electric and magnetic fields on calcium homeostasis and pineal gland function which potentially could have consequences for reproductive health. The purpose of this review is to report results of research to date in humans on maternal, paternal and fetal exposure to the 50-60 Hz fields associated with electricity, and to propose populations, endpoints and strategies for future research.

Adult↗
PubMed1991

The effects of Carbogen, carbon dioxide, and oxygen on noise-induced hearing loss.

An investigation into the effect of Carbogen (95% O2/5% CO2), 5% CO2/air, and 100% oxygen on cochlear threshold shifts caused by noise was undertaken. Five groups of eight pigmented guinea pigs were exposed to 105 dB broad band noise for 6 h per day for five consecutive days with each group receiving the various gaseous mixtures either during noise exposure or for 1 h immediately after noise exposure. A control group received the same noise exposure but respired air. Auditory threshold shifts, as measured by the auditory evoked brainstem response, were measured at 2,4,8,12,16, 20 and 24 kHz. Recordings were taken pre-exposure and at Day 1, 3, 5, and Weeks 2 and 3 after noise exposure. Carbogen, given during noise exposure, resulted in a trend toward less post noise exposure threshold shift (as compared to controls) which reached statistical significance by Week 3 at all frequencies except 2 and 20 kHz. Subjects given Carbogen after exposure also showed a general trend toward decreased noise induced threshold shifts, as compared to controls, but this was not statistically significant. The mixture of 5% CO2/air given during noise exposure yielded no difference in threshold shifts as compared to controls. When 100% oxygen was administered during noise exposure, a marked decrease in noise induced threshold shifts could be seen as compared to controls, with differences reaching statistical significance by day 5 at most frequencies. These results indicate that oxygen (i.e. cochlear-oxygenation) is a more important factor than CO2 (i.e., as a vasodilator) in protection of the cochlea from noise induced damage.

Animals↗
PubMed1991

A retrospective analysis of the metabolic status of stone formers in the New York City metropolitan areas.

Eighty stone-forming patients were evaluated as outpatients for risk factors involved in stone formation. Analyses of the major stone risk parameters in the 24-hour collections indicated low volume (less than 2L) in about 79% of these patients. Forty percent of all patients were found to be hypocitraturic, 30% were hyperoxaluric, 18% were hypercalciuric, and 13% were hyperuricosuric. Sixty-one percent of the patients had a normal calcium load study; of these, four patients were uric acid stone formers. The remaining 39% of patients were classified as either absorptive hypercalciuric (16 patients), or fasting hypercalciuric with normal (12 patients) or elevated (3 patients) serum parathyroid hormone (PTH) levels. Of these 31 patients, 61% were not hypercalciuric on the basis of the 24-hour urine collections. The protocol provided a diagnosis in over 98% of patients. Low urinary volume was the only defect found in 5% of patients, while more than one risk factor was identified in 93%.

Adult↗
PubMed1976

An enzymic method for the spectrophotometric determination of oxalic acid.

A simple method is described for the measurement of urinary oxalate. Oxalate decarboxylase is coupled with NAD+ requiring formate dehydrogenase and the result recorded spectrophotometrically. Accurate determination can be carried out either on urine or a citrate extract or urine. Using the citrate extract procedure, the urinary samples can be stored for at least 3 months without any effect on the oxalate content.

Oxalates↗