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To determine the prevalence of wheezing during the first year of life in Cantabria, Spain and its associated risk factors.

Incluso después de la promulgación del código de Nuremberg las investigaciones sobre sífilis continuaron alejándose en muchas ocasiones de los estándares éticos. En este artículo hemos revisado las investigaciones que sobre esta enfermedad tuvieron lugar después de la Segunda Guerra Mundial, centrándonos en los casos de Guatemala y de Tuskegee. En Guatemala durante los años 1946 a 1948 se inoculó deliberadamente a más de 1.000 adultos sífilis, chancroide y gonorrea, y se hicieron miles de serologías a poblaciones indígenas o a niños huérfanos. El experimento Tuskegee sobre sífilis fue realizado entre 1932 y 1972 por el Servicio Público de Salud de los Estados Unidos para estudiar la evolución natural de esta enfermedad en ausencia de tratamiento. Se realizó sobre un grupo de población rural de raza negra y no se interrumpió a pesar de la introducción de tratamientos eficaces para la resolución de la enfermedad durante estos años (1945).

Even after the Nuremberg code was published, research on syphilis often continued to fall far short of ethical standards. We review post-World War IIresearch on this disease, focusing on the work carried out in Guatemala and Tuskegee. Over a thousand adults were deliberately inoculated with infectious material for syphilis, chancroid, and gonorrhea between 1946 and 1948 in Guatemala, and thousands of serologies were performed in individuals belonging to indigenous populations or sheltered in orphanages. The Tuskegee syphilis study, conducted by the US Public Health Service, took place between 1932 and 1972 with the aim of following the natural history of the disease when left untreated. The subjects belonged to a rural black population and the study was not halted when effective treatment for syphilis became available in 1945.

Physicians have conducted research on syphilis for centuries, seeking to understand its etiology and the means of transmission as well as find ways to prevent and cure the disease. Their research practices often strayed from today's ethical standards. In this paper we review ethical aspects of the long history of research on syphilis with emphasis on the experiments performed in the 20th century. The description of research around the time of World War II covers medical experiments carried out in US prisons and in the experimentation centers established by Japanese doctors in occupied territory, as well as experiments in Nazi Germany and the treatment of syphilitics there.

Durante siglos la sífilis ha sido objeto de investigación por parte de los médicos, dado que la etiología, la forma de contagio, la profilaxis y el tratamiento eran desconocidos. En muchas ocasiones las investigaciones se han alejado de los estándares éticos actuales. En este artículo hemos revisado desde un punto de vista histórico y ético las investigaciones que sobre esta enfermedad se han ido realizando a lo largo de los siglos, centrándonos sobre todo en aquellos experimentos realizados en el siglo xx. Describimos con detalle los estudios realizados en los años que tuvieron lugar alrededor de la Segunda Guerra Mundial: experimentos realizados por los médicos norteamericanos en prisiones de Estados Unidos, la sífilis en la Alemania nazi o los ensayos realizados por los japoneses en centros de experimentación creados a tal fin en los territorios ocupados.

Characterization of multiphase systems occurring in fermentation processes is a time-consuming and tedious process when manual methods are used. This work describes a new semi-automatic methodology for the on-line assessment of diameters of oil drops and air bubbles occurring in a complex simulated fermentation broth. High-quality digital images were obtained from the interior of a mechanically stirred tank. These images were pre-processed to find segments of edges belonging to the objects of interest. The contours of air bubbles and oil drops were then reconstructed using an improved Hough transform algorithm which was tested in two, three and four-phase simulated fermentation model systems. The results were compared against those obtained manually by a trained observer, showing no significant statistical differences. The method was able to reduce the total processing time for the measurements of bubbles and drops in different systems by 21–50% and the manual intervention time for the segmentation procedure by 80–100%.Characterization of multiphase systems occurring in fermentation processes is a time-consuming and tedious process when manual methods are used. This work describes a new semi-automatic methodology for the on-line assessment of diameters of oil drops and air bubbles occurring in a complex simulated fermentation broth. High-quality digital images were obtained from the interior of a mechanically stirred tank. These images were pre-processed to find segments of edges belonging to the objects of interest. The contours of air bubbles and oil drops were then reconstructed using an improved Hough transform algorithm which was tested in two, three and four-phase simulated fermentation model systems. The results were compared against those obtained manually by a trained observer, showing no significant statistical differences. The method was able to reduce the total processing time for the measurements of bubbles and drops in different systems by 21–50% and the manual intervention time for the segmentation procedure by 80–100%.

The culture conditions of a multiphase fermentation involving morphologically complex mycelia were simulated in order to investigate the influence of mycelial morphology (Trichoderma harzianum) on castor oil and air dispersion. Measurements of oil drops and air bubbles were obtained using an image analysis system coupled to a mixing tank. Complex interactions of the phases involved could be clearly observed. The Sauter diameter and the size distributions of drops and bubbles were affected by the morphological type of biomass (pellets or dispersed mycelia) added to the system. Larger oil drop sizes were obtained with dispersed mycelia than with pellets, as a result of the high apparent viscosity of the broth, which caused a drop in the power drawn, reducing oil drop break-up. Unexpectedly, bubble sizes observed with dispersed mycelia were smaller than with pellets, a phenomenon which can be explained by the segregation occurring at high biomass concentrations with the dispersed mycelia. Very complex oil drops were produced, containing air bubbles and a high number of structures likely consisting of small water droplets. Bubble location was influenced by biomass morphology. The percentage (in volume) of oil-trapped bubbles increased (from 32 to 80%) as dispersed mycelia concentration increased. A practically constant (32%) percentage of oil-trapped bubbles was observed with pelleted morphology at all biomass concentrations. The results evidenced the high complexity of phases interactions and the importance of mycelial morphology in such processes.

The production of γ-decalactone by the filamentous fungus Trichoderma harzianum involves four phases (oil-water-air-mycelium) and its dispersion is crucial during fermentation. Oil and biomass (when present) dispersion, as a function of the volumetric power drawn (P/V), was characterized, in two; three- and four-phase systems agitated with Rushton turbines. Trichoderma harzianum mycelium was used as the solid phase in the four-phase system. Two stages of the fermentation were simulated: the beginning (15% oil and 1.4 kgm^-3 of mycelium) and the end (2% oil and 10.6 kg m^-3 of mycelium). In the two-phase system, the use of exhausted broth achieved higher oil dispersions at low P/V values as compared with distilled water. Aeration decreased the oil dispersion for the high-oil system, but enhanced oil dispersion for the low-oil system. Compared with the P/V used in the actual fermentation (0.2 kW m^-3), a high segregation of the system was observed for the high-oil/low-biomass system, due to the difficulty of mixing the thick oil-air emulsion present at the top of the tank. The system simulating the end of the fermentation reached almost complete homogeneity of oil and biomass, a phenomenon due to the high biomass/oil ratio and the biomass acting as an oil carrier.
© 2001 Society of Chemical Industry

The effect of oscillating dissolved oxygen tension (DOT) on the metabolism of an exopolysaccharide-producing bacteria (Azotobacter vinelandii) was investigated, particularly on the mean molecular weight (MMW) of the alginate produced. Sinusoidal DOT oscillations were attained by manipulating the oxygen and nitrogen partial pressures at the inlet of a 1.0 L working volume bioreactor. Periods of 1200, 2400, and 4000 s and average amplitudes between 1.0% and 2.2% DOT, with an oscillation axis fixed at 3% DOT, were tested. A culture carried out at constant 3% DOT was used as comparison. The average wave amplitude had an important effect on the maximum mean molecular weight (MMWmax) of the alginate produced. The higher the amplitude, the lower the MMWmax. As the average wave amplitudes decreased from 2.2% to 1.0%, the MMWmax increased from 64 to 240 KDa, respectively. Furthermore, at 3% constant DOT (0.0% of amplitude), a MMWmax of 350 KDa was obtained. No important effect of the oscillating DOT on kinetics of biomass growth, alginate production, and sucrose consumption was observed, compared with constant DOT. The findings of this study point out that accurate DOT control is crucial if a particular molecular weight species of alginate needs to be produced, particularly in large fermentors, where bacteria are exposed to an oscillatory environment as a result of DOT gradients caused by the high viscosity of the broth and insufficient mixing.

Abstract:: The known level energies, electromagnetic moments and decay probabilities of high-spin states in the N = 46 isotones 86Zr, 87Nb, 88Mo, 89Tc, and 90Ru are interpreted within the shell model. The single-particle space was truncated to the p 1/2 and g 9/2 orbits (relative to the 88Sr core) and the single-particle energies and empirical two-body matrix elements derived by Gross and Frenkel were used in the calculations. Based on the generally good success of this approach, energies and decay properties of the yrast spectra in 90Ru and 91Rh are predicted.

Abstract:: Subpicosecond lifetimes of high spin states in the rotational nuclei 73Se, 74Se and 74Br have been measured using the 58Ni +19F compound reaction and the Doppler Shift Attenuation method. Six EUROBALL Cluster detectors arranged in cube geometry allowed us to select the relevant transitions in γγ coincidence mode. The high counting statistics achieved in this setup also facilitated the determination of average sidefeeding times, which were found to agree rather well with the results of Monte-Carlo calculations of the particle and γ-ray evaporation process. The deduced quadrupole strengths and deformations are compared with the results of previous measurements and the predictions of Cranked Shell Model calculations. In 74Br, a large and constant prolate deformation of β2= 0.37(1) was found for the presumed 4+ and 3− two-quasiparticle bands.

Seventeen wild-type Xanthomonas isolates were screened in terms of broth viscosity in shake-flasks. As culture conditions affect polymer characteristics, a fair comparison among isolates required their cultivation in a fermenter under controlled dissolved oxygen tension. Three isolates and a reference strain were studied. The mean molecular weights and molecular weight distributions of their xanthans were determined. Products showed different pyruvate (0.2–7%), acetate (5–10%) and proteinaceous nitrogen (1–3%) contents. The selected isolates exhibit properties which could improve xanthan gum production and some could be used to produce polymers with specific characteristics.

Joint debridement was performed for advanced haemophilic arthropathy of the knee in eleven patients. Follow up was for an average of 5.4 years and the results were evaluated retrospectively by the Hospital for Special Surgery disability score sheet. The clinical results were excellent in four, good in five and fair in two. Debridement should be considered in the young haemophiliac to avoid, or delay, total knee arthroplasty. The operation may give the patient years of life without pain and it appears to slow the development of radiographic changes.

Twenty seven patients with haemophilia who had repeated haemarthroses affecting the knee joint, despite appropriate substitution therapy, were treated by surgical synovectomy. Open operations were carried out on 18 and 9 had an arthroscopic procedure. The average age at the time of synovectomy was 13 years for both the open and arthroscopic groups. The open group was followed up for an average of 15.2 years and the closed for 5.4 years. Operation took 70 minutes on average in the arthroscopic group and 50 minutes in the open. Patients who had an arthroscopy were in hospital for an average of 5 days and those with an open operation for 10. Synovectomy by both methods significantly reduced bleeding episodes. The results were assessed according to the classification recommended by the Orthopaedic Advisory Committee of the World Federation of Haemophilia. In the open group 2 patients had a good result, 10 were fair and 6 poor; in the arthroscopic group 3 had a good result, 5 were fair and 1 poor. Both operations appeared to slow, but did not halt, the radiographic deterioration of the joints.

Intra-articular injection of Au-198 (gold synoviorthesis) has been used in the treatment of repeated haemarthroses of the elbows, knees, or ankles in 64 haemophiliacs. These patients had continued to have joint haemorrhages despite appropriate, episodic, substitutive therapy over a period of more than six months. Follow-up for an average period of 14 years in one knee in 38 male haemophiliacs showed 8 good, 23 fair, and 7 poor results with regard to their joint scores.

Apparent yield stress is a very useful rheological property which is important in determining the extent of mixing in xanthan fermentations as well as the suspending ability of the gum solutions. Using a previously developed stress relaxation technique, three commercial products, one home-made product and one dehydrated-reconstituted fermentation broth (DRFB) were characterized in terms of the apparent yield stressty of solutions containing different polymer concentrations and when mono and divalent salts or sucrose were added and also when exposing the samples to heat treatment in the case of DRFB. Sodium, potassium, calcium, magnesium, acetate, pyruvate, the mean molecular weight (MMW) and the molecular weight distribution (MWD) were determined. Although the four products showed differences in their chemical characteristics, the pyruvic acid content and the mean molecular weight played the main role in determining the yield stress patterns. With no salt added, the slope of thetyvs gum concentration plot was a strong and inverse function of the pyruvate content. With NaCl 0.5%, the mentioned slope correlated linearly with the MMW. The three commercial xanthans showed very similar MWD. Xanthan broths showed an exponential, rather than a linear (as it was the case for end-products) function ofty in terms of xanthan concentration. No significative differences were found in ty depending on the type of salt. Sucrose decreasedty and this effect was more pronounced in DRFB than in a solution of a commercial xanthan.

Molecular diffusion of solutes, like sucrose in the xanthan gum fermentation, is important in order to understand the complex behavior of mass transfer mechanisms during the process. This work was focused to determine the diffusion coefficient of sucrose, a carbon source for xanthan production, using similar sucrose and xanthan concentrations to those occurring in a typical fermentation. The diaphragm cell method was used in experimental determinations. The data showed that diffusion coefficient of sucrose significantly decreases when xanthan gum concentration increases. Theoretical and semiempirical models were used to predict sucrose diffusivity in xanthan solutions. Molecular properties and rheological behavior of the system were considered in the modeling. The models tested fitted well the behavior of experimental data and that reported for oxygen in the same system.

Abstract: Two strains of X. campestris from a collection and a wild strain isolated from infected cabbage were cultured in a defined medium in a 25 dm3 fermenter. The rheological characteristics of the broth were measured using a Weissenberg rheogoniometer. The rheological behaviour over a wide range of shear rates could be described with the power law model and a yield stress was obtained using the Herschel-Bulkley equation. As expected, the broth's flow behaviour is highly influenced by gum concentration. In general, the rheological parameters during the fermentations varied within the following ranges: K (2–210 dyn-sn/cm2), n (0.2–0.9), τ y (0.02–50 dyn/ cm2), with strain 1459 reaching the maximum values as well as the highest gum concentration. Differences in flow behaviour could be associated with different molecular configurations of the polymers produced by the different strains. Heat treatment of the broths change the rheological characteristics, increasing K and decreasing n. Reconstituted solutions of all sterilized gums exhibited similar rheological characteristics and, at low concentrations, also similar to those of a commercial xanthan.

Viscoelasticity has important implications in mass transfer and mixing processes. Previous studies regarding to the viscoelastic behaviour of xanthan solutions have been carried out with diluted solutions or they have not covered a wide range of polymer concentrations. In this study, it was shown that the first normal stress difference measured in fermentation broths is highly dependent on shear rate, and this viscoelastic level is modified by the heat treatment to which the broths are subjected as a postfermentative procedure. The viscoelasticity level is different for xanthan solutions prepared with products arising from different sources and for fermentation broths before the heat treatment, if compared with that measured in end-products. In general, the higher the polymer concentration, the higher the viscoelasticity (expressed as first normal stress difference or Weissenberg number). The addition of a biocide, the change in ionic strength and the addition of sucrose to the xanthan solutions, lead to significant changes in the first normal stress difference.

During 1972 a large epidemic, in excess of 10,000 cases, of typhoid fever occurred in Mexico City, Pachuca, and other communities of Mexico. The main characteristic of the epidemic, in addition to the large number of persons affected, was the prevalence of a strain of Salmonella typhi which was highly resistant to chloramphenicol both in vivo and in vitro, and which belonged to a single phage type, Vi degraded approaching type A. Of 493 strains of S. typhi studied during the outbreak, 452 (91.7%) were resistant to chloramphenicol (CM), tetracycline (TC), streptomycin (SM), and sulfonamides (SU). The epidemic strain owes its resistance to an R factor which is easily transferable to Escherichia coli K-12 and which appears to be stable. In the third month of the outbreak, a strain of S. typhi resistant to CM, TC, SM, SU, ampicillin (AM), and kanamycin (KM) was isolated from a patient with severe typhoid fever. During the following 9 months, six additional strains of S. typhi resistant to AM, CM, TC, SM, and SU were also isolated. Transfer experiments to E. coli K-12 indicate that these strains are infected with two different R factors, one causing CM, TC, SM, and SU resistance and the other causing AM or AM and KM resistance. The frequency of transfer of the resistance in overnight crosses was in the order of 10(-4) for CM, TC, SM, and SU and 10(-6) for AM or AM, and KM. The appearance of these strains resistant both to chloramphenicol and ampicillin was a cause for concern for the clinicians; fortunately, they have remained an infrequent cause of disease.

The rheological complexity of Xanthan fermentations presents an interesting problem from a mixing viewpoint, because the phenomena of poor bulk blending and low oxygen mass transfer rates inherent in highly viscous fermentations (and their consequences) can be systematically investigated, even at the pilot plant scale. This study in a 150 L fermentor compares the physical and biological performance of four pairs of impellers: a standard Rushton turbine, a large diameter Rushton turbine, a Prochem Maxflo T, and a Scaba 6SRGT. Accurate in-fermentor power measurements, essential for the comparison of impellers in relation to operating costs are also reported. It is demonstrated that the agitator performance in Xanthan fermentations is very specific and the choice of which impeller to use in bioreactors to obtain enhanced performance is dependant on the applied criterion. None of the criterion favored the use of the standard Rushton turbine, therefore suggesting that there are strong grounds for retrofitting these impellers with either large diameter impellers of similar design or with novel agitators. In addition, fluid dynamic modeling of cavern formation has clearly highlighted the importance of a well mixed and oxygenated region for providing the capacity for high microbial oxygen uptake rates which govern Xanthan productivity and quality. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 95–108, 1998.

Recombinant plasmid pBP13, which expresses the alkaline lipase fromPseudomonas aeruginosa IGB83 under thetac promoter was transferred toXanthomonas campestris pvcampestris IBT148. Different fermentation conditions were tested for lipase productivity by strain IBT148 carrying plasmid pBP13, and a fermentation process was established in an instrumented bioreactor, where lipase production was increased more than 12-fold with respect to the initial culture conditions in shake flasks. Xanthan gum stabilized the activity of the alkaline lipase.

An outpatient study of 125 children with acute invasive diarrhea was conducted at the Hospital Infantil de Mexico Federico Gomez. Through a single-blind randomization, we compared the efficacy of furazolidone, 7.5 mg/kg/day (49 patients), with trimethoprim-sulfamethoxazole (TMP-SMX), 8 mg/40 mg/kg/day (52 patients), each given for 5 days. A control group of 24 patients received no antimicrobials. Stool samples were collected from all patients at the time of admission, and active drugs were administered before the stool culture results were available. At baseline, 48 of 125 patients (38.5%) had negative stool cultures. In the other patients, the most frequently isolated pathogens were Shigella sp and enteropathogenic Escherichia coli. Of the total population who completed the study 43 of 49 (87.8%) of the patients in the furazolidone group and 43 of 52 (82.7%) of the patients in the TMP-SMX group achieved clinical cure by day 3, compared with 10 of 22 (45.5%) of the patients in the control group. Day 3 cure rates were similar between groups, independent of baseline stool culture results. Of those patients who had positive stool cultures on day 1, 20 of 34 (58.8%) in the furazolidone group and 19 of 29 (65.5%) in the TMP-SMX group had negative culture results on day 6, compared with 4 of 12 (33.3%) in the control group. Overall, clinical and bacteriologic success was achieved in 31 of 49 (63%) patients treated with furazolidone and in 36 of 52 (69%) patients treated with TMP-SMX, compared with 5 of 22 (23%) patients in the control group. In the studied population there were no differences in clinical or clinical and bacteriologic cure rates between the antimicrobial groups; however, there was a significant difference in cure rates between antimicrobial groups and the control group (p < 0.001).

Chromogranin A (CGA) is a ubiquitous 48-kDa secretory protein present in adrenal medulla, anterior pituitary, central and peripheral nervous system, endocrine gut, thyroid, parathyroid, and endocrine pancreas. Recently, we have demonstrated that the protein could be a precursor of bioactive peptides capable of modulating catecholamine secretion from cultured adrenal medullary chromaffin cells. Here we cleaved CGA purified from bovine chromaffin granules with endoproteinase Lys-C, and we isolated and partially sequenced the peptide inhibiting catecholamine secretion from cultured chromaffin cells. A corresponding synthetic peptide composed of the first 20 N-terminal amino acids produced a dose-dependent inhibition in the 10(-9) to 10(-6) M range (with an ID50 of 5 nM) of the catecholamine secretion evoked by carbamoylcholine or by potassium at a depolarizing concentration. This peptide affected secretagogue-induced calcium fluxes but did not alter sodium fluxes. It was found to increase desensitization of cell responses and to modify the kinetics of catecholamine release. Our results indicate that the peptide is extracellularly generated from CGA by a calcium-dependent proteolytic mechanism. We suggest that this peptide, named chromostatin, may be an endocrine modulator of catecholamine-associated responses.

A bacterial mixed culture was immobilized in Millipore filters to construct microbial-membranes for BOD determination using an oxygen electrode. The biosensor response was best when 0.5 mg cells were immobilized per cm2of membrane, at 30°C, pH 7 and 0.05 M phosphate buffer. Reproducible microbial-membranes can be constructed and they can be stored for up to 20 days without appreciable loss of their response characteristics.

Abstract: The effect of different aeration conditions during the culture of Azotobacter vinelandii on the production and molecular mass of alginate was evaluated in shake flasks. In baffled flasks, the bacteria grew faster and produced less alginate (1.5 g/l) than in conventional (unbaffled) flasks (4.5 g/l). The viscosity of the culture broth was also influenced by the type of flask. Higher final viscosities were attained in unbaffled flasks [520 cP (520 mPa s)] as compared to baffled flasks (30 cP). This latter phenomenon was closely related to the changes in the molecular mass distribution. In either cases, the mean molecular mass increased with culture age; however, at the end of the fermentation, the mean molecular mass of the alginate obtained in unbaffled flasks was fivefold higher than that obtained in baffled flasks. As the culture proceeded, the cells of Azotobacter grown in unbaffled flasks increased in diameter, whereas those cultured in baffled flasks decreased in size.

Chromogranin A (CGA) is a secretory protein present in the adrenal medulla and in a variety of endocrine organs. This protein may serve as precursor for pancreastatin (PST) and for other biologically active peptides. Recently, chromostatin (CST), a CGA derivative, has been identified that possesses high biological activity. The cellular distribution of CST in various endocrine organs is completely unknown. Using immunohistochemistry on plastic sections, we investigated the occurrence and cellular distribution of CST, PST, and CGA in human endocrine pancreas of healthy and diseased states and in the adrenal medulla. In the normal and diabetic pancreas, CST immunoreactivity was localized exclusively in beta cells, which were mostly unreactive for PST and CGA. Both latter peptides were confined mainly to glucagon (alpha) cells. Insulinoma cells displayed strong insulin, PST, and CGA immunoreactivities, but they were faintly immunoreactive for CST or unreactive. Adrenal chromaffin cells exhibited strong immunoreactivity for CGA but lacked CST and PST immunoreactivities. Based on the peculiar distributive pattern of CST, PST, and CGA, we suggest that CGA is differentially processed in chromaffin and islet tissues and in insulinoma cells. The unique cellular localization of CST in the endocrine pancreas of normal and pathological conditions may indicate that CST is involved in beta-cell function.

Chromostatin is a 20-residue peptide derived from chromogranin A (CGA), the major soluble component of secretory granules in adrenal medullary chromaffin cells. One known biological function of chromostatin is to inhibit the secretagogue-evoked catecholamine secretion from chromaffin cells. Putative receptors are present on the chromaffin-cell plasma membrane, and the activation of such receptors leads to the inhibition of L-type voltage-sensitive calcium channels. We report here that exposure of chromaffin cells to chromostatin modifies neither cAMP and cGMP levels nor protein kinase C activity but does provoke the activation of soluble protein phosphatase (PPase) type 2A in a dose-dependent manner compatible with the peptide concentration inhibiting catecholamine secretion. The activation of the PPase as well as the inhibition of both secretagogue-induced Ca2+ entry and catecholamine secretion by chromostatin were all blocked by okadaic acid, a specific PPase inhibitor. We suggest that chromostatin directly or indirectly stimulates PPase-2A, dephosphorylating a target protein and lowering its activity in the secretory process.

Ninety-four U.S. students who acquired diarrhea in Mexico were treated with furazolidone (47 subjects) or ampicillin (47 subjects) on a double-blind random basis. Of 47 students, 26 (55%) who received furazolidone (100 mg four times daily for 5 days) recovered from illness within 48 h after initiation of therapy, in contrast to 15 of 47 (32%) who received ampicillin (500 mg four times daily for 5 days) (P less than 0.05). Altogether, 74% of students treated with furazolidone and 49% of those receiving ampicillin were well within 72 h (P less than 0.05). When furazolidone was compared with ampicillin, clinical illness was shortened on the average from 65 to 61 h for enterotoxigenic Escherichia coli diarrhea, from 83 to 58 h for shigellosis, from 82 to 51 h for diarrhea unassociated with a detectable agent, and from 72 to 57 h for all cases irrespective of etiology. Although not dramatically effective in the current trial, the broad spectrum of activity of furazolidone is of interest. Because of in vitro activity against Campylobacter strains and known effectiveness in treating giardiasis, furazolidone should be considered in therapy for diarrhea of unknown etiology in certain settings when laboratory processing of stools for etiological agent is not feasible.

One of the functions of chromogranin A (CGA), the major soluble component of secretory granules in both adrenal medullary chromaffin cells and many other endocrine cell types appears to be that of a prohormone. CGA is the precursor of several peptides including pancreastatin, a 49-residue peptide, and a 20-residue peptide, chromostatin, which have been identified as biologically active peptides. Chromostatin produces a dose-dependent inhibition (ID50 of 5 nM) of the secretagogue-evoked catecholamine secretion from chromaffin cells. Here we report that chromostatin potently inhibits L-type calcium currents recorded with the nystatin-perforated patch technique in cultured chromaffin cells. This inhibitory effect of chromostatin on calcium currents was not observed in experiments using the classical patch-clamp whole-cell approach which induces the leakage of cytoplasmic components. Using 125I-chromostatin, we show that chromostatin exhibits a fully reversible and saturable binding to the plasma membrane of cultured chromaffin cells. Analysis of binding experiments at equilibrium indicates the existence of one class of binding sites with a Bmax of 2.7 pmol/mg of chromaffin cell proteins and an apparent Kd of 6.5 nM. This high affinity is in good correlation with the half-maximal concentration (ID50 5 nM) of chromostatin inhibiting catecholamine secretion from chromaffin cells. Specificity of the chromostatin binding was further assessed by displacement experiments with unlabeled CGA-related or -unrelated peptides. We found an excellent quantitative correlation between the affinities of the various peptides determined by binding assays and their functional potency tested on catecholamine secretion: bovine chromostatin greater than human chromostatin greater than CGA much greater than rat chromostatin, pancreastatin, CAP-14, substance P, and Leu-enkephalin. Cross-linking experiments reveal that chromostatin associates specifically with an 80-kDa plasma membrane protein. These results together with the patch-clamp experiments support the idea that chromaffin cells possess specific chromostatin receptors and that activation of such receptors leads to the inhibition of L-type voltage-sensitive calcium channels through an intracellular second messenger pathway.

Production of γ-decalactone, a compound having peach-like aroma characteristics, by a strain of Trichoderma harzianum is reported here for the first time. Cultures were carried out in a 14 L fermentor using castor oil as the sole carbon source. The filamentous-like growth of the microorganism resulted in highly viscous and non-Newtonian broths, which caused the formation of stagnant zones in the fermentor. T. harzianum was able to produce 260 mg/L of γ-decalactone after 7 days of culture in a stirred fermenter operated at 3.3 s^-1 and 1 vvm of air flow rate. The production of γ-decalactone was mainly non-growth associated. The use of high agitation rates&sbd;to improve mixing&sbd;resulted in celullar lysis. Cell damage occurred at volumetric power drawn as low as 0.2 W/L. Mycelial morphology (mainly hyphal thickness) changed drastically along the culture and was an important influence on the rheology of the broths. All these characteristics make this system an interesting model of study of hydrodynamically complex fermentations involving up to four phases.

Las malformaciones uterinas congénitas son poco frecuentes. El útero bicorporal tiene una prevalencia de 0,4%. Generalmente asintomática, se puede manifestar como dolor pélvico por un hematómetra o menstruación retrógrada de un cuerno uterino no comunicante. Se presenta el caso de una niña de 10 años que, en el contexto de dolor abdominal y fiebre, se realizan pruebas de imagen y se objetiva un útero bicorporal ocupado por lo que parece un hematómetra. Se interviene a la paciente para drenar el mismo, vía histeroscópica y laparoscópica comprobándose que se trataba de un piometra. Se realiza la hemihisterectomia sin incidencias con el fin de preservar su fertilidad y resolver el cuadro infeccioso.

Abstract:  Twenty-eight patients with displaced intra-articular fractures of the calcaneus treated by open reduction and fixation were compared with 30 patients with similar fractures treated conservatively. Judged by the clinical and radiographic criteria results were more satisfactory in the surgical group than in the nonoperative group, although high rates of poor results were encountered in both groups.

Baffled 500 ml Erlenmeyer flasks were compared with conventional 2800 ml Fernbach flasks forXanthomonas campestris to produce xanthan. Bacterial growth rates were similar in both types of flask although the Fernbach flasks gave higher biomass concentrations. Xanthan production was similar in both types of flasks but different viscosities were attained. On a weight basis, the xanthan produced in baffled flasks was up to three times more viscous and more pseudoplastic or ‘shear thinning’. For screening purposes, baffled flasks are better because the rheological quality of the gum produced in them is more like that obtained in stirred fermentors than the gum from Fernbach flasks and considerably less shaker space is required, thus allowing a larger number of tests to be performed.