Abnormal gastric emptying in primary anorexia nervosa

The gastric emptying rate was measured in 10 female patients with primary anorexia nervosa and 12 healthy volunteers, using a scinti-scanning technique for the simultaneous study of the liquid and solid components of a test meal. The emptying rate of both the liquid and the solid phase components of the meal was significantly slower in patients with anorexia nervosa. The aetiological and therapeutic implications of this finding are discussed.

Probenecid and intraocular methicillin

Probenecid was given intravenously to rabbits in an effort to extend the intraocular longevity of intravitreal methicillin. With relatively high levels of probenecid, an insignificant elevation of half-life was obtained. Aqueous levels of methicillin were measured after intravitreal injection and were found to be adequate to inhibit penicillinase-producing S. aureus for approximately 20 hours.

Effect of N-(phosphonacetyl)-L-aspartate on 5-azacytidine metabolism in P388 and L1210 cells

The effect of N-phosphonacetyl-L-aspartate (PALA) pretreatment on the metabolism and cytotoxicity of 5-azacytidine (5-aza-Cyd) was studied in two murine leukemic cell lines. Exposure of P388 and L1210 cells to 3 mM PALA for 3 hr before adding 5-aza-Cyd at 75 microM was accompanied by a two-fold increment in acid-soluble and 3-fold increment in acid-insoluble incorporation of 5-aza-Cyd in both cell lines. RNA incorporation of 5-aza-Cyd increased from 97.5 +/- 3.4 pmol 5-aza-Cyd per microgram D-ribose in control cells to 299.2 +/- 4.2 pmol 5-aza-Cyd per microgram D-ribose in PALA-treated cells; a smaller increment in DNA incorporation of 5-aza-Cyd was also noted. Sequential treatment of cells with PALA and 5-aza-Cyd was associated with a 40% reduction in protein synthesis compared to only a 2 and 8% reduction, respectively, produced by the drugs given alone. Sequential administration of PALA and 5-aza-Cyd resulted in greater than additive cytotoxicity as measured by both growth inhibition and in vitro soft-agar cloning assays. Exposure of both cell lines to 3 mM PALA for 3 hr produced 50 and 65% reductions in intracellular levels of cytidine triphosphate and uridine triphosphate; intracellular accumulation of 5-azacytidine triphosphate, the lethal metabolite of 5-aza-Cyd, increased from 43.4 +/- 2.1 pmol/10(6) cells to 92.4 +/- 3.3 pmol/10(6) cells in PALA-treated cells. PALA was able to augment the metabolism and cytotoxicity of 5-aza-Cyd in a uridine-cytidine kinase-mutant 5-aza-Cyd-resistant L5178Y subline. This sequential drug combination has a rational biochemical basis and may offer significant advantages over either drug when administered alone, especially in cells which are resistant to 5-aza-Cyd.

Altered 5-azacytidine metabolism following 3-deazauridine treatment of L5178Y and human myeloblasts

The effect of 3-deazauridine pretreatment on 5-azacytidine metabolism was studied in suspension cultures of L5178Y murine leukemia. A 3-hr exposure to 2 microM 3-deazauridine followed by a 1-hr exposure to 5 microM [14C]-5-azacytidine resulted in a 2-fold increase in total intracellular 5-azacytidine accumulation compared to untreated controls. Under the same conditions, incorporation of 5-azacytidine into the acid precipitable fraction of L5178Y cells was increased 3-fold. Incorporation of 5-azacytidine into RNA increased 85% following 3-deazauridine pretreatment, but 5-azacytidine incorporation into DNA did not change significantly. In cells pretreated with 3-deazauridine, there was an 80% reduction of intracellular cytidine triphosphate, the natural feedback inhibitor of uridine-cytidine kinase, the rate-limiting enzyme in the phosphorylation of 5-azacytidine. Intracellular levels of 5-azacytidine triphosphate, the presumed lethal metabolite of 5-azacytidine, increased from 28.8 pmol/10(6) cells in control cells to 56.4 pmol/10(6) cells following 3-deazauridine treatment. The sequence of 3-deazauridine followed by 5-azacytidine demonstrated synergistic cell killing when measured by an in vitro soft-agar cloning assay. Similar biochemical alterations were also seen in human leukemic myeloblasts. It appears that 3-deazauridine-induced alterations in 5-azacytidine metabolism may account for the enhanced cytotoxicity of this drug sequence.

Vitreous cylinders

Vitreous cylinders, a rarely discussed ophthalmologic entity, were studied in two clinical cases and in five enucleated eyes. The cylinders were found in four cases of ocular toxoplasmosis, one case of vitreous hemorrhage complicating a malignant melanoma, and one case of pars planitis and one of uveitis, both of unknown causes. Results of scanning electron microscopy in one specimen suggested that cylinders are formed by condensation of vitreous collagen fibers. We emphasize the nonspecific nature of this interesting vitreous finding.

Acute rheumatic fever and rheumatic heart disease on the Navajo reservation, 1962-77

The occurrence of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) among Navajos was ascertained for the period from 1962 through 1977 by means of hospital discharge diagnoses and patients' charts. The annualized attack rate for ARF was 12.4 per 100,000 population, with no clear evidence of an overall secular trend. The proportion of recurrences (19.6 percent) and clinical features were similar to those reported elsewhere, but no seasonal variation in attack rates was noted. Between 1962-71 and 1972-77, the age of RHD patients increased, suggesting few newly diagnosed cases and the aging of known patients. A streptococcal disease control program was instituted in many Navajo elementary schools before 1975. In the program, throat cultures were performed routinely for some asymptomatic children and for all symptomatic children. During the subsequent 3 years, ARF rates declined from 13.5 to 8.2 per 100,000 in areas covered by the program, while in the noncovered areas the rates showed little change-9.5 to 10.1 per 100,000.

Bacillus cereus endogenous panophthalmitis

A case of severe suppurative endogenous panophthalmitis caused by Bacillus cereus resulted from intravenously administered medications. This is the first, to our knowledge, well-documented case of endogenous endophthalmitis associated with this organism. It is recommended that if on Gram's stain of the anterior chamber fluid, Gram-positive rods are seen, chloramphenicol should be administered in addition to penicillin because of the possibility of B cereus infection.

STUDIES ON THE UPTAKE OF RAGWEED POLLEN ALLERGENS BY POLYAMINOSTYRENE

Polystyrene (PS), polyaminostyrene (PAS), and the diazonium salt of polyaminostyrene (DPAS) were compared for their capacity to bind ragweed pollen allergens. PAS was slightly more efficient than DPAS in this respect although the binding was non-specific. Nevertheless, the allergens could not be eluted from PAS with saline. PS appeared to be unable to bind the pollen allergens. DPAS coupled to tyrosine was as efficient as DPAS in binding the pollen allergens.

STUDIES ON THE UPTAKE OF REAGIN BY POLYAMINOSTYRENE–RAGWEED COMPLEXES

The various factors governing the uptake of reagin by insoluble antigenic complexes prepared by incubating ragweed pollen extract (WSR) with either polyaminostyrene (PAS) or diazopolyaminostyrene (DPAS) have been investigated. It was found that PAS–WSR was as capable of binding reagin as DPAS–WSR. This reaction was shown to be specific and the quantity of reagin bound to the complex was found to vary with the amount of reagin present during the incubation and the duration of incubation. The binding was independent of the concentration of reagin in the incubation mixture and of the temperature of incubation.