Anterior ischemic optic neuropathy in Buerger's disease

A 77-year-old man with a history of Buerger's disease developed an anterior ischemic optic neuropathy. This disease, while rare in the United States at the present time, is common in other parts of the world. None the less, this appears to be the first reported case of this type of optic neuropathy in a patient with documented Buerger's disease. A possible mechanism is suggested.     

Systemic effects of intraocular epinephrine during cataract surgery

This paper examines the effects of intraocular epinephrine on systemic blood pressure and heart rate during cataract surgery. Sixty-two patients were studied, all of whom received an intraocular infusion of approximately 200 to 300 mL of balanced salt solution with 0.5 mL of epinephrine 1:1000. There was no statistically significant change in blood pressure or heart rate during the time of epinephrine administration. Electrocardiogram monitoring during surgery showed no changes. We believe that dilute concentrations of epinephrine administered during extracapsular cataract extraction pose little threat of systemic toxicity.     

Elimination of antibiotic-resistant plasmids by quinolone antibiotics

Of 7 plasmids we tested, the plasmid pORF2 was eliminated in vitro with the most efficiency by treatment with subinhibitory concentrations of novobiocin, coumermycin and 10 quinolones. It showed a cure rate of 43% by enoxacin; 12% by novobiocin, pefloxacin, ciprofloxacin and CI-934; 7% by coumermycin and ofloxacin; 9% by amifloxacin; and 4% by AM-833. On the other hand, pSC194, pBR322 and pMH612 were poorly cured in vitro by quinolones, except pSC194 which was cured 33% by enoxacin. R1, pP1603, and pUB110 were unaffected by the treatment. Mice were challenged intraperitoneally with a 2XLD50 of Escherichia coli carrying the ORF2 plasmid and were treated per os with 1 X or 1/2 X ED50 of either enoxacin or CI-934. The frequency of loss of ampicillin resistance determined 3 h after treatment shows curing effects of 92% for CI-934, 89% for enoxacin and 20% for untreated control.     

The combination of prazosin and verapamil in the treatment of essential hypertension

An exaggerated fall in blood pressure has been reported with the combination of an alpha 1-blocker and a calcium antagonist. This study investigated, in a placebo-controlled, randomized crossover trial, the clinical usefulness of the combination of prazosin (2 mg b.i.d.) and verapamil (160 mg b.i.d.). Therapeutic efficacy was monitored at regular outpatient visits: average supine and erect blood pressures were, respectively, 175/99 and 176/103 mm Hg with placebo, 160/91 and 164/96 mm Hg with single drug treatment, and 152/84 and 152/89 mm Hg with combination therapy. This significant and clinically useful reduction in blood pressure had an overall magnitude of approximately 28/18 mm Hg (supine) and 29/19 mm Hg (erect). Further measurements were made during a series of intensive study days, and the most important additional finding was a pharmacokinetic interaction that resulted in increased peak concentrations and bioavailability of prazosin. In conclusion, the combination of prazosin and verapamil proved effective in the treatment of 12 patients with essential hypertension who had been poorly responsive to conventional treatment with a beta-blocker and thiazide diuretic.     

An analysis for blood manganese used to assess environmental exposure

In this graphite-furnace atomic-absorption spectrometric method for measuring manganese in whole blood, we use a pyrolytic platform to minimize interference by sample matrix. For optimal sample ashing we denature the sample within the furnace with nitric acid and use oxygen as the purge gas at low temperatures. The mean manganese concentration found in blood from 15 unexposed city dwellers was 215 (2 SD 135) nmol/L. By comparison, the range of manganese concentrations in blood sampled from a group of Australian aborigines living near a surface manganese ore deposit on Groote Eylandt, Northern Territory, was much higher (median 405 nmol/L, range 175 to 990 nmol/L).     

Brain mechanisms in the control of food intake—30 years on

Do brain systems exist which control not only increases or decreases in food intake, but also bring about specific changes in the size and distribution of meals consumed, alter the selection of particular macronutrients and adjust feeding responses to the perceived pleasantness (hedonic value) of the food? A cautious yes can be given to each of these questions. Moreover, since most experimental work has been carried out on the brains of animals, we can also ask how well these animal data relate to the human condition; given the methodological issues involved in making such inferences, the answer is remarkably well.