Bacterial spectra and antibiotics in odontogenic infections. Renaissance of the penicillins?]

BACKGROUND: The role played by odontogenic infection in dental, oral, and maxillofacial surgery is not to be underestimated even at the present time. An extensive, standardized, prospective study was performed with the intention of verifying the bacterial spectrum of odontogenic infections to evaluate antibiotic sensitivity. MATERIAL AND METHODS: Bacterial spectra and resistograms of 65 patients with an odontogenic infection were analyzed in a prospective study under standardized conditions for specimen collection and transport. RESULTS: A total of 226 bacterial strains were analyzed. The ratio between anaerobes and aerobes was approximately 2:1. The most frequent aerobes were members of the genera Streptococcus (46 isolates), Staphylococcus (10 isolates), and Neisseria (9 isolates), respectively. The anaerobic gram-positive spectrum was dominated by members of the genera Eubacterium (19 isolates), Peptostreptococcus (16 isolates), and Actinomyces (12 isolates). The most frequently isolated gram-negative anaerobes were Prevotella (46 isolates), and Fusobacterium (21 isolates).The overall resistance to antibiotics was very low: only 7.3% of all bacteria were resistant to penicillin G/V, and 8.8% showed resistance to ampicillin. The resistance rates to other beta-lactam antibiotics were 4.4% to piperacillin and 0.6% to imipenem, respectively.Penicillin G presented the highest antimicrobial activity among aerobes: only 4.5% of anaerobic strains were resistant of penicillin G. The other resistance rates of anaerobic bacteria to antibiotics were as follows: ampicillin 24%, doxycycline 34%, erythromycin 18%, and clindamycin 9.3%. Penicillin G was also highly antimicrobially active to anaerobes. The resistance rates were: penicillin G 8.1%, ampicillin 2.6%, doxycycline 9.2%, erythromycin 10.2%, and clindamycin 1.4%, respectively.     

Evaluation of sperm morphology using Kruger's strict criteria.

Prospective and retrospective studies were conducted to evaluate sperm morphology using strict criteria for predicting fertilization capacity in males. Severely impaired male fertility potential was measured by a result of less than or equal to 4% (denotes percentage sperm having normal morphology) and scores of greater than 14% indicated normal fertilization potential. There were no statistically significant differences found in pregnancy rates in partners of men with normal morphology of less than or equal to 4% vs. those with 14% or greater (chi 2 analysis): the prospective study showed a 41% pregnancy rate in less than or equal to 4% group vs. 29% rate in greater than 14% group (p = 0.44 NS); the retrospective analysis showed a 50% pregnancy rate in the group with less than or equal to 4% morphology scores vs. 67% in greater than 14% group (p = 0.45 NS). When only the men with normal motile density (greater than 10 x 10(6)/ml) were evaluated, a statistical difference was found in the retrospective study between the group with morphology results greater than 14% (93%) vs. the group less than or equal to 4% (40%). However, the 56% success rate in the men with less than 10 x 10(6)/ml sperm and normal morphology less than or equal to 4% reduces the significance of the diagnosis of sperm morphology using the new strict criteria.     

Development of presynaptic inhibition onto retinal bipolar cell axon terminals is subclass-specific.

Synaptic integration is modulated by inhibition onto the dendrites of postsynaptic cells. However, presynaptic inhibition at axonal terminals also plays a critical role in the regulation of neurotransmission. In contrast to the development of inhibitory synapses onto dendrites, GABAergic/glycinergic synaptogenesis onto axon terminals has not been widely studied. Because retinal bipolar cells receive subclass-specific patterns of GABAergic and glycinergic presynaptic inhibition, they are a good model for studying the development of inhibition at axon terminals. Here, using whole cell recording methods and transgenic mice in which subclasses of retinal bipolar cells are labeled, we determined the temporal sequence and patterning of functional GABAergic and glycinergic input onto the major subclasses of bipolar cells. We found that the maturation of GABAergic and glycinergic synapses onto the axons of rod bipolar cells (RBCs), on-cone bipolar cells (ON-CBCs) and off-cone bipolar cells (OFF-CBCs) were temporally distinct: spontaneous chloride-mediated currents are present in RBCs earlier in development compared with ON- and OFF-CBC, and RBCs receive GABAergic and glycinergic input simultaneously, whereas in OFF-CBCs, glycinergic transmission emerges before GABAergic transmission. Because on-CBCs show little inhibitory activity, GABAergic and glycinergic events could not be pharmacologically distinguished for these bipolar cells. The balance of GABAergic and glycinergic input that is unique to RBCs and OFF-CBCs is established shortly after the onset of synapse formation and precedes visual experience. Our data suggest that presynaptic modulation of glutamate transmission from bipolar cells matures rapidly and is differentially coordinated for GABAergic and glycinergic synapses onto distinct bipolar cell subclasses.     

Predictors of oral mucositis in patients receiving hematopoietic cell transplants for chronic myelogenous leukemia.

PURPOSE: Oral mucositis is a nearly universal and often severe complication following hematopoietic cell transplantation (HCT). The objective of this study was to evaluate factors predicting oral mucositis severity among 133 patients undergoing allogeneic HCT for chronic myelogenous leukemia. PATIENTS AND METHODS: All patients were transplanted between 1992 and 1999, were >or= 18 years of age, received either cyclophosphamide/total-body irradiation (TBI) or busulfan/cyclophosphamide conditioning regimens, and received four doses of methotrexate for graft-versus-host disease prophylaxis post-transplant. Oral mucositis was measured by a trained examiner every 2 to 3 days using the Oral Mucositis Index (OMI). Multiple linear regression analysis was used to identify predictors of mean OMI during days 6 to 12, 1 to 18, and the maximum OMI score between days 1 to 18. RESULTS: TBI containing conditioning regimens, body mass index >or= 25, and methylenetetrahydrofolate reductase 677 TT genotype were found to be predictive of higher mean OMI scores (P <.05). Pretransplant multivitamin supplement use was associated with lower mean OMI scores compared to those who did not use supplements. Smoking status, race, pretransplant treatment with interferon-alfa or hydroxyurea, and patient/donor ABO compatibility were not associated with mean OMI scores. CONCLUSION: Patients who are scheduled to receive conditioning regimens containing TBI, have a pretransplant body mass index >or= 25, or carry the methylenetetrahydrofolate reductase 677 TT genotype should be considered at greater risk of developing oral mucositis following HCT. Future studies should investigate whether multivitamin supplementation before HCT could reduce mucositis severity.     

Promising preclinical activity of 2-methoxyestradiol in multiple myeloma.

PURPOSE: 2-Methoxyestradiol (2ME2), a natural endogenous product of estradiol metabolism, has demonstrated activity against tumor cell lines and can inhibit angiogenesis. There are limited treatment options for patients with multiple myeloma (MM) who relapse after high-dose therapy and stem cell transplantation. We studied the preclinical activity of 2ME2 as a therapeutic agent for myeloma. EXPERIMENTAL DESIGN: Five established myeloma cell lines as well as primary plasma cells from patients with MM were exposed to 2ME2 at various concentrations. We evaluated the activity of the drug to inhibit cell replication and induction of apoptosis in vitro as well as the ability of the drug to inhibit myeloma tumor xenograft growth in severe combined immunodeficient mice. RESULTS: 2ME2 inhibited tritiated thymidine uptake in all myeloma cell lines tested in a dose-dependent fashion and induced G(2)-M phase cell cycle arrest. The drug induced apoptosis in all cell lines tested and in half of the primary plasma cells evaluated in a dose-response manner. Forty-eight h after drug exposure, a large proportion of the cells were dead by propidium iodide staining. Injection of the drug i.p. suppressed myeloma tumor xenograft growth, and the effect was sustained after cessation of therapy. CONCLUSIONS: 2ME2 has significant activity against myeloma cell lines and primary myeloma cells both in vitro and in an animal model. Clinical trials are required to evaluate its activity in patients with MM.     

Development and perspectives of experimental pancreas transplantation in the rat

Whole organ pancreas transplantation in the rat was first described by Sun Lee in 1972. Since that time the basic technique has been modified in several ways and this model can now be used for a variety of experiments. Various techniques for transplantation and representative results of functional and immunological experiments are summarized.     

Comparison of four anti-HIV screening assays which belong to different test generations.

There are three different test generations of enzyme-linked immunosorbent assays (ELISA) for the detection of human immunodeficiency virus (HIV) infection, depending on whether virus lysate, recombinant proteins or synthetic peptides are used as solid phase antigen. Four different assays, i.e., three sandwich ELISAs and one competitive test, were used to demonstrate differences between the three systems with regard to the content of different diagnostically relevant virus proteins. The sensitivities and specificities of these assays were compared by using 312 anti-HIV positive sera and 500 sera of healthy blood donors. The highest sensitivity and specificity were achieved by the competitive ELISA based on recombinant proteins, and by the sandwich ELISA based on synthetic peptides.     

Intraoperative measurement of velocity and volume of coronary circulation using the Duplex system

A high frequency ultrasound system processor was used for an intraoperative evaluation of coronary blood flow velocity and volume. In 12 patients with symptomatic coronary heart disease, morphology and hemodynamic parameters of the coronary artery system were examined intraoperatively. Optimal imaging was possible by keeping the ultrasound transducer at a constant distance of a few millimeters from the surface of the heart and the pericardial space between them filled with saline solution. Using this technique, large areas of the cardiovascular system were reproducible up to a peripheral vascular diameter of 2-3 mm. Blood flow velocity (20 to 33 cm/s) and blood volumes (33 to 94 ml/min) provide quantitative information on the degree of stenosis intraoperatively after coronary anastomosis during bypass surgery. All images were of outstanding quality and precision. This method is highly valuable for the intraoperative determination of blood flow parameters.