An immunocytochemical study of isolated human retinal Müller tells in culture

Background: We report a modified method for the isolation and propagation of adult human Müller cells in culture. Methods: The retina of postmortem human eyes was mechanically dissociated and cultured. Using immunocytochemical techniques, these cells were stained with monoclonal antibodies specific for Müller cells, glial fibrillary acidic protein (GFAP), vimentin, glutamine synthetase (GS) and keratin. Transmission electron microscopy (TEM) was also performed. Results: The dissociated and cultured cells expressed vimentin and GS, but not GFAP. At least 85% of these cells stained with a Müller tell-specific monoclonal antibody. Using TEM, flat cells containing 13-nm intermediate filaments and glycogen were identified. Conclusion: Human retinal Müller cells tan be isolated and propagated in culture. Purified cell cultures are required for controlled studies of the normal physiology and pathologie responses of Müller cells.     

Effects of acetylcholine, carbachol, and mannitol on rabbit corneal endothelial function as assessed by corneal deturgescence

Background: Anterior chamber miotic solutions are widely used in ophthalmic surgery to induce pupillary contraction. We investigated whether the acetylcholine, carbachol, or mannitol present in perfusing solutions can affect corneal endothelial function. Methods: Freshly dissected deepithelized rabbit corneas were mounted in a Dikstein-Maurice chamber at 36 °C. The endothelial sides were perfused with six solutions: (A) 55 mM (1%) acetylcholine Cl plus modified balanced salts; (B) control for A, with acetylcholine Cl replaced by sucrose; (C) 0.55 mM (0.01%) carbachol Cl plus balanced salts; (D) balanced salts solution (BS; control for C); (E) 3% mannitol plus modified balanced salts; and (F) modified balanced salts (control for E, with mannitol replaced by sucrose). Corneal thickness was followed for 3 h in each experiment. The effect of solution E did not differ from that of solution F. Results: The carbachol-containing solution produced a small increase in corneal thickness compared to the control solution, while the acetylcholine-containing solution resulted in corneal thickness lower than that in control preparations. Conclusion: From these data, acetylcholine is harmless to the endothelium, and may actually stimulate its fluid pump mechanism. Carbachol, on the other hand, appears to have a detrimental effect.     

Health care delivery system. Effects on surgical education: The Mexican panorama

Health care delivery in Mexico is divided in three groups: a social sector that covers approximately 53% of the population and is financed by the labor force, the state and the employer; a public, or open, sector that covers 33% of the population and is financed by federal and state funds; and a private sector that covers about 5% of the population and has two categories, the not-for-profit hospitals and the profit-oriented institutions. Most medical practitioners can work in any of the three groups or in several. Nine percent of Mexico's population, because of extreme ignorance, poverty, or isolation, have no or limited access to medical care. Mexico has 58 medical schools, which graduate about 7800 new physicians annually, awarding them the title Medico cirujano (Physician Surgeon). There are more than 160,000 physicians in Mexico, 20,000 of whom are unemployed. Each year, approximately 12,000 physicians compete for the 4306 places in the official residency training programs for all specialties. Of those taking the examination, 2000 try to get one of the 625 slots available for training in general surgery. Most of the surgical training programs in Mexico have a 3-year duration. The Mexican Academy of Surgery, the Mexican Society of General Surgery, and the Mexican Board of Surgery, as well as private individuals and organizations, are working to improve the quality of medical education and trying to establish a 5-year training program in surgery. The rapid movement toward modernization that is sweeping the country must include the improvement of surgical education as well.

---

Resumen La atención de la salud en México está dividida en tres grupos: el Sector Social que cubre approximadamente el 53% de la población y que está financiado por la fuerza laboral, el Estado y el empleador; un Sector Público o Abierto que cubre el 33% de la población y que es financiado con fondos federales y estatales; y un Sector Privado que cubre el 5% de la población y que posee dos categorías: la de los hospitales sin ánimo de lucro y la de las instituciones con ánimo de lucro. La mayoría de los médicos pueden trabajar en cualquiera de los 3 grupos, o en combinación. El 9% de la población mexicana, por extrema ignorancia, pobreza y aislamiento no posee acceso alguno, o sólo lo tiene mínimo, a la atención médica.México posee 58 facultades de medicina, las cuales gradúan alrededor de 7.800 nuevos médicos anualmente, a quienes se les expide el título de médico cirujano.Hay más de 160.000 médicos en México, 20.000 de los cuales se encuentran desempleados. Cada año aproximadamente 12.000 médicos compiten por las 4.306 plazas en los programas oficiales de adiestramiento en las diferentes especialidades. De aquellos que presentan examen, 2.000 tratan de obtener uno de los 625 lugares disponibles para adiestramiento en círugía general.La mayoría de los programas de adiestramiento quirúrgico en la nación son de tres años de duración. La Academia Mexicana de Cirugía, la Asociación Mexicana de Cirugía General y el Consejo Mexicano de Cirugía, así como individuos y organizaciones privadas, trabajan en pro del mejoramiento de la calidad de la educación médica y tratan de establecer un programa de adiestramiento en cirugía de cinco años de duración. Los rápidos cambios de modernización que ocurren en el país deben incluir también el mejoramiento de la educación quirúrgica.

---

Résumé L'administration des soins au Mexique est repartie entre trois secteurs: 1) Le secteur social qui couvre environ 53% de la population et qui est financé par la caisse des ouvriers, celle de l'état et celle du patronat; 2) un secteur public ou ouvert, qui couvre environ 33% de la population et qui est financé par des fonds fédéraux et gouvernementaux et enfin 3) un secteur privé, qui ne couvre que 5% environ de la population et qui comprend deux catégories, les hôpitaux à but non-lucratif et les institutions à but lucratif. La plupart des médecins peuvent exercer dans un ou plusieurs de ces trois groupes. Neuf pourcent de la population, en raison d'une extrême pauvreté, de son ignorance ou de son éloignement, a peu ou pas d'accés à des soins structurés.Il y a 58 écoles de Médecine au Mexique, produisant environ 7800 nouveaux médecins par an. Ils reçoivent le titre de Medico Cirujano littéralement, Médecin chirurgical. Il existe plus de 160000 médecins au Mexique, dont 20000 sont sans travail. Chaque année, environ 12000 médecins sont en compétition pour obtenir un des 4306 postes officiels de résidents, toutes spialités confondues. Parmi ceux qui se présentent, 2000 sont candidats pour un poste en chirurgie. La plupart des programmes d'enseignement durent trois ans. L'Académie de Chirurgie Mexicaine, La Société Mexicaine de chirurgie Générale et le comité d'accréditation chirurgicale, tout en accord avec les institutions privées et leur dirigeants oeuvrent pour un programme de cinq ans. La vague de progrès, ressentie dans tous les domaines, qui traverse actuellement le pays doit aussi intéresser l'amélioration de l'enseignement en chirurgie.

     

Assessment of polynuclear aromatic hydrocarbons ecotoxicity threshold in marine sediments through in situ input/decay measurements

The ability of decomposers to process variable amounts of xenobiotics in the marine sediment is a useful aggregate indicator of their capacity to prevent their accumulation and eventual ecotoxic effects. Since decomposition processes depend on environmental factors at the sediment which are difficult to mimic in laboratory systems, in situ evaluations in undisturbed sediments are of great interest. A method and its results are presented to evaluate the decomposition rates of PAHs (polynuclear aromatic hydrocarbons) in coastal undisturbed marine sediments at different levels of pollution input. The method is based on the application of pulse chromatography concepts to interpret trap and bed sediment monitoring data obtained at regular time intervals, using models of the water column as an anisotropic carrying medium. The results are for a 14 month data series from moderately polluted sediments near an urban site and at a more distant nearly pristine site on the south Atlantic coast. QSAR (quantitative structure activity relations) indicate that decay rates increase with higher UV absorption and lipidic solubility. At low levels of total PAH input to the sediments (<0.05 g day^–1 g^–1), decomposition mechanisms effectively process these compounds within a few days. At higher input levels (up to 0.12 g day^–1 g^–1), decomposition lags behind the inputs by approximately 25% and PAHs accumulate in the sediment. In situ estimates of the PAH input/decay ratios provide reliable ecosystem indicators of a safe threshold for anthropogenic inputs of PAHs to the marine environment and a basis for receptor-based standards aimed at their regulation.     

Functional consequences of inhibition of nucleotide breakdown in rat vas deferens: a study with Evans blue

The effect of Evans blue on nucleotide breakdown, nucleotide-evoked contractions and electrically evoked contractions, overflow of ATP and overflow of tritium (after labelling with [³H]-noradrenaline) was studied in rat vas deferens. Pieces of vas deferens degraded 83 to 85% of added ATP, ADP and 2-methylthio ATP (all 100 M) over 30 min. Evans blue (100 M) reduced this degradation to 22 to 26%. Nucleotides elicited contraction with potency declining in the order , \-methylene ATP > 2-methylthio ATP > ATP > ADP. Evans blue (100 M) shifted the concentration-response curve of , \-methylene ATP to the right and increased the maximum. Concentration-response curves of ATP, ADP and 2-methylthio ATP, in contrast, were shifted to the left and responses were much potentiated. In the presence of Evans blue, the rank order of potency was ATP > 2-methylthio ATP > , \-methylene ATP > ADP. Electrical field stimulation (100 pulses at 10 Hz) elicited contraction and an overflow of tritium and ATP. Evans blue (100 M) did not alter the contraction and the evoked overflow of tritium but increased 24-fold the evoked overflow of ATP. The results indicate that Evans blue may serve as an — albeit impure — ecto-nucleotidase inhibitor in functional experiments. Such experiments demonstrate that the low potency of ATP (and also ADP and 2-methylthio ATP) in eliciting contraction, and the small size of the overflow of ATP upon sympathetic nerve stimulation, are due to rapid breakdown.     

Virtual Changes of the Shape of the Lips

Many of the unsatisfactory results in cosmetic surgery are due not to the technique employed itself but to the virtual changes that our work has imposed in other areas. These changes are especially evident in the face, due to the small dimensions of its organs. The surgeon should do a thorough evaluation of the area to be treated prior to the surgery and make her/him notice not only the usual existing asymmetries, but also the modifications which probably will be noticed in the neighboring parts after surgery, to avoid later problems. The surgeon will discover then the many irregularities a patient may have, which have not been noticed by the patient before. These, if not detected in time, are weapons that may act as a boomerang against the surgeon later.     

Semen Parameters Before and After Transurethral Surgery for Ejaculatory Duct Obstruction

Purpose

We examined how transurethral resection of the ejaculatory ducts, performed for infertility, affects semen quality in patients with azoospermia and oligo-asthenospermia.

Materials and Methods

A retrospective review was done of 46 cases of transurethral resection of the ejaculatory ducts for ejaculatory duct obstruction, confirmed by transrectal ultrasound. Clinical course and semen quality were assessed by semen parameter indications.

Results

In 65 percent of the patients transurethral resection of the ejaculatory ducts improved semen quality (greater than a 50 percent increase in total motile sperm count) and 20 percent initiated a pregnancy an average of 6.1 months postoperatively. Statistically significant increases in total motile sperm count were achieved in men with azoospermia and those treated for oligo-asthenospermic indications; the improvement also was shown to be sustainable. Complications occurred in 20 percent of the men.

Conclusions

Significant and durable semen quality improvement can be achieved after transurethral resection of the ejaculatory ducts for all surgical indications. In most unsuccessful cases the reason for failure is unclear.     

Haemodynamic consequences and uterine contractions following 0.5 or 1.0 litre crystalloid infusion before obstetric epidural analgesia

Purpose

The efficacy of infusion of 0.5 L and 1.0 L Ringer’s lactate (LR) to prevent hypotension during induction of obstetric analgesia was studied. The effect of the different fluid boluses on fetal heart rate (FHR) and frequency of uterine contractions were also determined.

Methods

Ninety-two ASA 1–2 parturients were randomized to receive 0.5 L (Group 1) and 1.0 L (Group 2) LR immediately before incremental epidural injections with lidocaine to achieve T₁₀ sensory block. Systolic blood pressure (SBP) was measured with an automated BP cuff every two minutes for 30 min after infusion of fluid bolus. Fetal heart rate monitoring and tocometry were used continuously. The number of uterine contractions were recorded 30 min before and 60 min after iv bolus.

Results

The SBP decreased in both groups, but there was no difference between groups in mean SBP or maternal heart rate. The incidence of hypotension (SBP < 90 mmHg or decrease of 20%) was 4% in both groups. The FHR record of a patient in Group 1 showed a single late deceleration, and a decrease in beat-to-beat variability occured in one patient in Group 2. A decrease in the frequency of uterine contractions of two or more contractions per 30 min was noted more frequently in Group 2 (P < 0.05). The duration of iv bolus was longer in Group 2 than Group 1 (18.8 ± 4.3 min vs 12.3 ± 4.5 min, P < 0.01).

Conclusion

Administration of 1.0 L LR iv does not provide added protection against maternal hypotension, and is associated with delay in providing pain relief and a risk of decreasing uterine contraction frequency.     

The mutagenic potential of the furylethylene derivative 2-furyl-1-nitroethene in the mouse bone marrow micronucleus test.

The compound 2-furyl-1-nitroethene (G-0) has been tested to determine its ability to induce clastogenic or aneugenic effects in vivo, through the induction of micronucleated polychromatic erythrocytes (MNPCE) in mouse bone marrow. Groups of five CD-1 male mice were administered once intraperitoneally at a dose range of 5-20 mg/kg and bone marrow was sampled at 24 and 48 h after the treatment. G-0 was dissolved in corn oil, thus a vehicle control group received only corn oil at 10 ml/kg. The positive control group was administered with cyclophosphamide (40 mg/kg). All animals dosed with the highest concentration of the test agent (20 mg/kg) showed evident clinical symptoms of toxicity. Although evidences of bone marrow toxicity were observed, no statistically significant increases in the incidence of MNPCE over the vehicle control group were observed at any sampling time with any of the assayed doses of the G-0 compound. Cyclophosphamide treatment increased the incidence of MNPCE in all treated animals, demonstrating the sensitivity of the assay conditions in which it was carried out. From the results obtained, it is concluded that the test agent G-0 is neither clastogenic nor aneugenic in the erythrocytes from the bone marrow of treated mice at the doses tested.     

Phase II study of denileukin diftitox for relapsed/refractory B-Cell non-Hodgkin's lymphoma.

PURPOSE: Denileukin diftitox is a fusion protein combining diphtheria toxin and interleukin-2 (IL-2) that targets tumor cells expressing the IL-2 receptor. Its efficacy has been shown in CD25+ cutaneous T-cell lymphoma, but not in B-cell non-Hodgkin's lymphoma (NHL). A phase II study was performed to evaluate the efficacy and tolerability of denileukin diftitox for relapsed or refractory B-cell NHL. PATIENTS AND METHODS: Patients with relapsed or refractory B-cell NHL were eligible. Tumor CD25 expression was determined by immunohistochemistry or flow cytometry. Denileukin diftitox was administered intravenously at a dose of 18 microg/kg once daily for 5 days every 3 weeks, up to eight cycles. RESULTS: Of the 45 patients assessable for response, 32 (71%) were refractory to the last chemotherapy treatment, and all were previously treated with rituximab. Three complete responses (6.7%) and eight partial responses (17.8%) were observed, for an overall response rate of 24.5%. Nine patients (20%) had stable disease. Objective response rates were similar in CD25+ (22%) and CD25- histologies (29%), as were stable disease rates (22% and 18%, respectively). For responding patients, the median time to treatment failure was 7 months, with a median follow-up in survivors of 18 months (range, 9 to 28 months), and the projected progression-free survival at 20 months was 24% (95% CI, 0% to 60%). Most toxicities were low-grade and transient. CONCLUSION: Denileukin diftitox seems to be effective in relapsed or refractory, CD25+ and CD25- B-cell NHL and is well-tolerated at the dosage evaluated. Evaluation of denileukin diftitox in combination with other agents may be warranted.