Conduction disturbances in patients with calcified mitral annulus diagnosed by echocardiography

Clinical, radiologic and histo-pathological observations have suggested that conduction disturbances (CD) are frequent in patients with calcified mitral annulus (CMA). To determine the incidence of CD, 65 consecutive patients with CMA were studied. Sixty-five normal individuals, matched for age and sex served as a control group. CMA has been identified by M-mode echocardiography, cross-sectional echo and image amplifier fluoroscopy. CD were present in 23 patients with CMA as compared to seven patients in the control group (p less than 0.01). Three patients developed complete atrioventricular block (4.6%) during hospitalization requiring artificial pacemakers. We conclude that, 1) early detection of CMA in the elderly is useful in predicting a higher incidence of CD. 2) Complete heart block is more frequent in patients with CMA. 3) Frequent ECG follow-up in these patients has proven to be useful in avoiding serious clinical complications.

Method for qualitative determination of 2-deoxystreptamine

We have developed a qualitative method to assay for the presence of 2-deoxystreptamine in hydrolysates of crude aminoglycoside preparations using a 2-deoxystreptamine-requiring idiotrophic mutant. The assay involves (i) incubation of a 2-deoxystreptamine-requiring mutant with 1 mg of a hydrolyzed preparation from a crude unknown antibiotic mixture per ml, and (ii) examination of the resultant incubation mixture for production of antibiotic(s) by disk assay.

Gallium-68 labeled red cells and platelets: new agents for positron tomography

Red cells and platelets are labeled with Ga-68 by preparing the tga-68-hydroxy-quinoline (oxide) complex and mixing the complex with the separated cellular components. The complex is prepared by first breaking the Ga-68 EDTA chelate with concentrated hydrochloric acid, adsorption of the galluim on a strong anionic ion-exchange column, and elution of the gallium activity with distilled water. Oxine is added, the oxine complex extracted into chloroform, and--following evaporation and dissolution--the solution is added to either red cells or platelets that have been centrifuged from whole blood, washed, and suspended in normal saline. After 15 min of incubation , labeling efficiencies of greater than 90% and yields of 7 mCi are obtained from 18 mCi of Ga-68 EDTA eluted from the generator. After injection of the gallium-labeled red cells in dogs, excellent blood pool images were obtained by positron tomography. The distribution corresponded to that of 11CO-labeled red cells. When labeled platelets were injected into dogs with experimentally induced intimal injury of on carotid artery, the area of injury was clearly visualized 40 min after tracer injection.

Human splanchnic metabolism during diabetic ketoacidosis

Splanchnic exchange rates of glucose, acetoacetate, beta-hydroxybutyrate, lactate, pyruvate, glycerol, alanine, glutamine, glutamate, free fatty acids, and triglycerides were measured in eight patients during moderate to severe diabetic ketoacidosis. Their arterial glucose concentration was 20.68 (9.80-52.79) mumole/liter and tic glucose release was 0.77 (0.09-2.44) mmole/min. Gluconeogenesis accounted for about one-half of net splanchnic glucose release, assuming quantitative conversion of net splanchnic extracted lactate, pyruvate, glycerol, alanine, and alpha-ketoglutarate equivalents to glucose. Net splanchnic free fatty acid extraction was 0.24 (0.09-0.52) mmole/min. There was a positive correlation between free fatty acid uptake and ketone-body release. Net splanchnic acetoacetate release was 0.50 (0.05-0.92) mmole/min and beta-hydroxybutyrate release was 0.35 (-0.16 to 0.84) mmole/min. Total ketone-body release was 0.84 (0.37-1.61) mmole/min. The wide ranges of net splanchnic glucose and ketone-body production rates show the heterogeneous characteristics of the diabetic patient in ketoacidosis. It is concluded that the hyperglycemia and hyperketonemia of diabetic ketoacidosis is due to the lack of reciprocity among rates of hepatic glycogenlysis, gluconeogenesis, and ketogenesis resulting in inappropriate net splanchnic release of glucose and ketone bodies.

A new actinomycin complex produced by a Micromonospora species: fermentation, isolation, and characterization

A species of Micromonospora, Micromonospora floridensis NRRL 8020, has been found to produce an actinomycin complex consisting of at least 25 active components. After solvent extraction of the complex, separation of the individual components was carried out by preparative thin-layer chromatography. Hydrolysis and subsequent electrophoretic and chromatographic identification of the amino acid content of each of the isolated components have shown differences from known actinomycins, and the probability exists that these contain a number of amino or imino acids not previously found in other members of this group of antibiotics.

Effects of prophylactic antibiotics on colonic healing

The effect of antibiotic colon preparation on the tensile strength and morphologic appearance of colonic anastomoses has been investigated in dogs. Preparation with preoperative kanamycin did offer a slight benefit over mechanical bowel cleansing. The addition of erythromycin and kanamycin to the preoperative bowel preparation significantly (p less than 0.001) improved the mean tensile strengh of the healing colonic anastomosis. Continuation of erythromycin and kanamycin for one week postoperatively almost doubled the mean tensile strength of the healing anastomosis. Continuation of erythromycin without kanamycin in the postoperative period provided little protection over the preoperative administration of kanamycin and erythromycin. Histologic examination showed that erythromycin and kanamycin given during the pre- and postoperative period changed the mode of healing from that of secondary intention to healing by first intention. The findings support the concept that soilage of the peritoneal cavity at the time of elective colon surgery is not as important as leakage caused by poor anastomotic healing. Antibiotic bowel preparation with kanamycin and erythromycin improves the healing of colonic anastomoses.

Dissolution patterns of polydisperse powders: oxalic acid dihydrate

The dissolution of oxalic acid dihydrate crystals of log-normal particle-size distribution in 0.1 N HC1 was studied. A biphasic cube root dependence was found; the slopes of the initial cube root plots were consistent with theory based on dissolution of isometric, isotropic particles where assumptions were made of: (a) sink conditions, (b) particle-size-independent solubility, and (c) particle-size-independent film thickness of adsorbed liquid layers.

Nonsink dissolution rate equations

In spite of the fact that film theory is based on severe assumptionss, it is shown to be a good working model. The Niebergall-Goyan equation, the Short-Sharkey-Rhodes equation, and the Pothisiri-Carstensen equation-all based on simple film theory-are shown to hold through 80-90% of the dissolutin process for p-hydroxybenzoic acid and sodium chloride, both at values below and above the amount necessary to saturate the dissolution medium. Deviations are attributed to experimental difficulties and to improper definition of monodisperseness rather than to the assumptions made in the theory.

New polyene antifungal antibiotic produced by a species of Actinoplanes

A new species of Actinoplanes, which has been deposited with the designation NRRL 5325 at the Northern Utilization Research and Development Division of the U. S. Department of Agriculture, produces a polyene antifungal complex designated as Sch 16656. The complex, consisting of one major and three minor components, is isolated from the fermentation broth by a solvent extraction procedure and purified by precipitation methods. The major component is a heptaene and is highly active in vitro and in vivo against Candida albicans. It is active also against strains of Torulopsis and is significantly more potent orally than candicidin in mice against Candida infections.