Evaluation of the new RapID-ANA II system for the identification of clinical anaerobic isolates.

The RapID-ANA II System (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) is a recently revised and marketed 4-h system for the identification of anaerobic bacteria. The system was compared with conventional identification methods for its ability to identify 566 clinical anaerobic isolates. Overall, the system identified correctly to genus and species 68% of the total isolates (62% of 204 gram-negative bacilli, 70% of 69 nonsporeforming gram-positive bacilli, 74% of 130 Clostridium isolates, and 72% of 163 anaerobic cocci), without the use of additional tests. With the additional tests suggested by the manufacturer, 78% of the total isolates were identified correctly to species. The routine use of a few simple and practical tests (e.g., egg yolk agar for Clostridium spp.), in addition to the RapID-ANA II, would improve significantly the accuracy of the system in the identification of anaerobic bacteria. This second-generation system offers a number of improvements over the original system, including an updated data base and the option of overnight refrigeration of the system before the addition of reagents.     

Questioning the efficacy of Fallopian tube sperm perfusion

The aim of this work was to compare the efficiency of standard intrauterine insemination (IUI) and Fallopian tube sperm perfusion (FSP) in the treatment of infertility. Ninety-six consecutive patients with infertility in 100 cycles were included in the study. Those randomized to standard IUI included 48 patients in 50 cycles [25 clomiphene citrate only and 25 clomiphene citrate/human menopausal gonadotrophin (HMG) cycles] (group I). Patients subjected to FSP included 48 patients in 50 cycles (18 clomiphene citrate only and 32 clomiphene citrate/HMG cycles) (group II). The overall pregnancy rate per cycle (16% versus 18%) was not significantly different in the two groups. The pregnancy rates were also similar in the two groups when compared for the cause of infertility: ovulatory disorder 16.7% versus 16%, tubal impairment 10% versus 9.1%, cervical hostility (no pregnancy occurred in this group) and unexplained infertility 21.4 % versus 25 %. The overall pregnancy rate (for the two groups) appeared higher when clomiphene citrate/HMG was used for ovulation induction (21.1%) than when clomiphene citrate only was used (11.6%).      

Changes in rat plantaris motor unit profiles with advanced age

The physiological characteristics of single motor units in rat plantaris muscles were determined in situ, for young adult (3 months) and very old (30–34 months) Fischer 344 rats. Old muscles generated 43% less tetanic force (P₀) per gram. Motor units classified as “slow”, using criteria of fatigue resistance and “sag” during unfused tetani, had a mean P₀ which was 255% of that in young muscles, while fast motor units were similar in P₀ in the two groups. Estimates were made of motor unit numbers using whole muscle and mean motor unit P₀ values. The typical young plantaris contained 48 units, of which 5–6 were slow, while old plantaris contained 29 units, of which 11 were slow. In spite of this large increase in slow motor unit presence (increased mean motor unit P₀, plus increased number) in old muscles, a comparatively modest (72%) increase occurred in the muscle cross-section occupied by histochemically demonstrated slow fibres. During senescence, there occurs a loss in muscle tetanic force capability which is accompanied by a loss of motor units and a reorganization of the remaining motor unit profile. An increase in slow motor unit number and size with advancing age can evidently occur without concomitant histochemical changes. Motor units do not “dedifferentiate”, but maintain their physiological distinctiveness into very old age.     

Apparent glucose utilization in Walker 256 metastatic brain tumors

Regional rates of apparent glucose utilization (GU) in metastatic Walker 256 (WL-256) brain tumors produced by the intracarotid injection of WL-256 tumor cells in rats were measured using¹⁴C-deoxyglucose and quantitative auroradiography. Apparent glucose utilization was uniform within individual small and medium size tumors without necrosis, varied considerably among different tumors within this group, and did not correlate with tumor size or location. High values of GU in medium and large-size tumors correlated with viable-appearing tissue in contrast to necrotic tissue and were always 1.3 to 3 times higher than that of adjacent and contralateral nontumorous brain. The apparent net extraction of glucose (E _n ^* ) in viable tumor regions was estimated to be several fold higher than that in remote brain tissue; analysis of this data for medium and large tumors indicates that the calculated values of GU and E _n ^* overestimate the actual rates of utilization and net extraction of glucose. Local cerebral glucose utilization (LCGU) was higher than normal adjacent to small tumors and lower than normal adjacent to large tumors. The LCGU in many gray-matter structures remote from the intracerebral tumors was reduced and roughly proportional to the metastatic tumor burden. The comparatively high uptake of 2-deoxyglucose by viable tumor cells has diagnostic and localization value and suggests that appropriate glucose analogues could be developed to produce a tumor-selective inhibition of glycolysis and tumoricidal effect.An abstract of this work has been presented: M. Shinohara, R. Blasberg, C. Patlak, W. Shapiro: Metastatic brain tumors: local cerebral glucose utilization, Neurology 29: 545, 1979     

Prediction of chemotherapy response in human leukemia using an in vitro chemotherapy sensitivity test on the leukemic colony-forming cells

An in vitro test system to quantitatively assess the chemotherapy sensitivity of human acute leukemic colony-forming cells (L-CFU) in relation to normal granulocytic precursor cells (CFU-C) has been developed. After simultaneous exposure of leukemic and normal bone marrow cells to individual drugs in vitro, cells were grown using an improved agar culture method with daily feeding. A sensitivity index (SI) was determined as the ratio of survival fraction of CFU-C to that of L-CFU, L-CFU being more (or less) sensitive than CFU-C if the SI were higher (or lower) than unity. Thirty SI were determined for 6 single drugs actually given in various combinations to a total of 9 patients (8 with acute nonlymphocytic leukemia and 1 with chronic myelomonocytic leukemia). A highly significant correlation was observed between high (or low) SI and achievement of (or failure to achieve) complete remission, with only 6 false correlations (p = 0.0013). Also, the mean of these SI (MSI) for the multiple single drugs given to each patient as components of a combination chemotherapy was used to indicate an overall sensitivity for each trial of the chemotherapy. Among the 10 chemotherapy trials (1 trial each for 8 patients and 2 trials for 1 patient), 4 trials resulting in complete remission had MSI higher than 1.0, and 6 trials not resulting in complete remission had MSI lower than 1.0 (p = 0.0048). This assay system appears useful in predicting the response of patients to chemotherapy and in the selection of the most effective drugs for use in individual patients.