Somatic innervation contributes to the release of bulbourethral gland secretion in male rats.

BACKGROUND: In male rats, the bulbourethral glands (Bu-Gs) are the unique accessory sexual glands surrounded by striated musculature. However, until now the role of this musculature was unknown. OBJECTIVES: (i) To characterize the Bu-Gs striated muscular layer in male rats and determine its innervation and response to genital stimulation. (ii) To reveal the role of the Bu-Gs striated musculature in the release of glandular secretion. (iii) To elucidate the effect of bilateral ablation of the Bu-Gs on copulatory behavior and seminal fluid characteristics. MATERIALS AND METHODS: Adult Wistar male rats were allocated in three experiments: in Experiment 1, the Bu-Gs striated musculature, innervation and reflex activity were determined by gross anatomy and histological and electrophysiological techniques; electromyographic activity of the Bu-Gs striated musculature was evoked with genital stimulation. In Experiment 2, Bu-Gs were analyzed after copulatory behavior of intact or animals with unilateral transected motor branch of the sacral plexus (MBSP). In Experiment 3, copulatory behavior and spermatobioscopy of males with bilateral ablation of the Bu-Gs or sham surgery were analyzed. RESULTS: The Bu-Gs striated fibers discharged in response to mechanostimulation of the prepuce, glans, and penile-urethra. Innervation of the Bu-Gs striated musculature originated from the MBSP; this nerve also innervates striated penile muscles. Unilateral transection of the MBSP significantly decreased the secretion from the ipsilateral Bu-G to the nerve transection. Bilateral ablation of Bu-Gs did not affect seminal plug formation but decreased semen viscosity. DISCUSSION AND CONCLUSION: The Bu-Gs striated musculature contributes to expel glandular secretion during sexual intercourse. The somatic control of Bu-Gs secretion is additional to the reported autonomic innervation supplied by the cavernosus nerve, which may underlie the synthesis of secretion as well as contraction of Bu-Gs smooth muscle.

Neuroanatomic and behavioral correlates of urinary dysfunction induced by vaginal distension in rats.

The aim of the present study was to use a model of simulated human childbirth in rats to determine the damage to genitourinary structures and behavioral signs of urinary dysfunction induced by vaginal distension (VD) in female rats. In experiment 1, the length of the genitourinary tract and the nerves associated with it were measured immediately after simulated human delivery induced by VD or sham (SH) procedures. Electroneurograms of the dorsal nerve of the clitoris (DNC) were also recorded. In experiment 2, histological characteristics of the bladder and major pelvic ganglion of VD and SH rats were evaluated. In experiment 3, urinary parameters were determined in conscious animals during 6 h of dark and 6 h of light before and 3 days after VD or SH procedures. VD significantly increased distal vagina width (P < 0.001) and the length of the motor branch of the sacral plexus (P < 0.05), DNC (P < 0.05), and vesical nerves (P < 0.01) and decreased DNC frequency and amplitude of firing. VD occluded the pelvic urethra, inducing urinary retention, hematomas in the bladder, and thinness of the epithelial (P < 0.05) and detrusor (P < 0.01) layers of the bladder. Major pelvic ganglion parameters were not modified after VD. Rats dripped urine in unusual places to void, without the stereotyped behavior of micturition after VD. The neuroanatomic injuries after VD occur alongside behavioral signs of urinary incontinence as determined by a new behavioral tool for assessing micturition in conscious animals.

Equilibrium susceptibilities of superparamagnets: longitudinal and transverse, quantum and classical.

The equilibrium susceptibility of uniaxial paramagnets is studied in a unified framework which permits us to connect traditional results of the theory of quantum paramagnets, S = 1/2,1,3/2,..., with molecular magnetic clusters, S∼5,10,20 all the way up (S = 30,50,100,...,) to the theory of classical superparamagnets. This is done using standard tools of quantum statistical mechanics and linear-response theory (the Kubo correlator formalism). Several features of the temperature dependence of the susceptibility curves (crossovers, peaks, deviations from Curie law) are studied and their scalings with S identified and characterized. Both the longitudinal and transverse susceptibilities are discussed, as well as the response of the ensemble with anisotropy axes oriented at random. For the latter case a simple approximate formula is derived too, and its range of validity assessed, which could be used in the modelization of experiments.

Low-field susceptibility of classical Heisenberg chains with arbitrary and different nearest-neighbour exchange.

Interest in molecular magnets continues to grow, offering a link between the atomic and nanoscale properties. The classical Heisenberg model has been effective in modelling exchange interactions in such systems. In this, the magnetization and susceptibility are calculated through the partition function, where the Hamiltonian contains both Zeeman and exchange energy. For an ensemble of N spins, this requires integrals in 2N dimensions. For two, three and four spin nearest-neighbour chains these integrals reduce to sums of known functions. For the case of the three and four spin chains, the sums are equivalent to results of Joyce. Expanding these sums, the effect of the exchange on the linear susceptibility appears as Langevin functions with exchange term arguments. These expressions are generalized here to describe an N spin nearest-neighbour chain, where the exchange between each pair of nearest neighbours is different and arbitrary. For a common exchange constant, this reduces to the result of Fisher. The high-temperature expansion of the Langevin functions for the different exchange constants leads to agreement with the appropriate high-temperature quantum formula of Schmidt et al, when the spin number is large. Simulations are presented for open linear chains of three, four and five spins with up to four different exchange constants, illustrating how the exchange constants can be retrieved successfully.

Spin dynamics in a dissipative environment: from quantal to classical.

We address the problem of spin dynamics in the presence of a thermal bath, by solving exactly the appropriate quantum master equations with continued-fraction methods. The crossover region between the quantum and classical domains is studied by increasing the spin value , and the asymptote for the classical absorption spectra is eventually recovered. Along with the recognized relevance of the coupling strength, we show the critical role played by the structure of the system-environment interaction in the emergence of classical phenomenology.

Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution.

AIM: To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers. METHODS: Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing. RESULTS: The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India. CONCLUSION: Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.

[Skin abscess as the clinical presentation of Pott's disease]. / Abscesos cutáneos como forma de presentación de la enfermedad de Pott.

Interest in skeletal tuberculosis has been growing in our environment due to the presence of patients with immunodeficiency and those from areas where tuberculosis is endemic. Clinical presentation in the form of skin abscesses with an osteoarticular focus is rare, hindering early diagnosis and treatment. We describe the case of an 8-year-old immigrant boy with a diagnosis of bone tuberculosis based on the presence of skin fistulas.

Abscesos cutáneos como forma de presentación de la enfermedad de Pott / Skin abscess as the clinical presentation of Pott´s disease

La tuberculosis espinal recobra interés clínico en nuestro medio con la presencia de pacientes inmunodeprimidos o bien procedentes de áreas endémicas para tuberculosis. La presentación clínica en forma de abscesos cutáneos a partir de un foco osteoarticular constituye una rareza y dificulta el diagnóstico y el tratamiento precoces. Se presenta el caso clínico de un niño inmigrante, de 8 años, diagnosticado de tuberculosis ósea a partir de la presencia de fístulas cutáneas (AU)

Tuberculosis abdominal seudotumoral / Pseudotumoral abdominal tuberculosis

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Large quantum nonlinear dynamic susceptibility of single-molecule magnets.

The nonlinear dynamical response of Mn12 single-molecule magnets is experimentally found to be very large, quite insensitive to the spin-lattice coupling constant, and displaying peaks reversed with respect to classical superparamagnets. It is shown that these features are caused by the strong field dependence of the relaxation rate due to the detuning of energy levels between which tunneling takes place. The nonlinear susceptibility technique, previously overlooked, is thus proposed as a privileged probe to ascertain the occurrence of quantum effects in mesoscopic magnetic systems.

Subset of hybrid eukaryotic proteins is exported by the type I secretion system of Erwinia chrysanthemi.

Erwinia chrysanthemi exports degradative enzymes by using a type I protein secretion system. The proteases secreted by this system lack an N-terminal signal peptide but contain a C-terminal secretion signal. To explore the substrate specificity of this system, we have expressed the E. chrysanthemi transporter system (prtDEF genes) in Escherichia coli and tested the ability of this ABC transporter to export hybrid proteins carrying C-terminal fragments of E. chrysanthemi protease B. The C terminus contains six glycine-rich repeated motifs, followed by two repeats of the sequences DFLV and DIIV. Two types of hybrid proteins were assayed for transport, proteins with the 93-residue-protease-B C terminus containing one glycine-rich repeat and both hydrophobic terminal repeats and proteins with the 181-residue C terminus containing all repeat motifs. Although the shorter C terminus is unable to export the hybrids, the longer C terminus can promote the secretion of hybrid proteins with N termini as large as 424 amino acids, showing that the glycine-rich motifs are required for the efficient secretion of these hybrids. However, the secretion of hybrids occurs only if these proteins do not carry disulfide bonds in their mature structures. These latter results suggest that disulfide bond formation can occur prior to or during the secretion. Disulfide bonds may prevent type I secretion of hybrids. One simple hypothesis to explain these results is that the type I channel is too narrow to permit the export of proteins with secondary structures stabilized by disulfide bonds.

[Poisoning by Robinia pseudoacacia]. / Intoxicación por Robinia pseudoacacia.

We present a 7 boys Robinia pseudoacacia (black locust) intoxication. Three of them showed neurological symptoms, including coma. All of them showed gastrointestinal symptomatology. Evolution was satisfactory in all of them. A bibliographic revision is done.

[Maternal-fetal transmission of HIV in Catalonia and the Balearic Islands]. / Transmisión materno-infantil de la infección por el virus de la inmunodeficiencia humana (VIH) en Cataluña y Baleares.

Two hundred and ninety three cases of children born of HIV positive mothers have been observed between January 1984 and June 1988 in Catalonia and Balearic Islands, with a ration of 9.5/10,000 newborns. Sex was not significant in the infected group. Most of the cases (68%) have been detected since 1987 and represent a significant increase in HIV positive children and thus of those who will present with clinical manifestations of this infection.

Rehidratacion por via bucal en ninos hospitalizados de la ciudad de Mexico / Oral rehydration in hospitalized children in Mexico city

Ingresaron al Servicio de Urgencias del Hospital de Pediatria del Centro Medico Nacional del IMSS, 358 pacientes con deshidratacion por gastroenteritis, de los cuales 292 (81.5 por ciento), fueron tratados por el metodo de rehidratacion por via bucal. Se obtuvo exito en 268 (91.8 por ciento) tomaron voluntariamente la solucion hidratante; a 58 (21.7 por ciento) se les administro por gastroclisis. Reingresaron 17 pacientes de los cuales 9 se rehidrataron nuevamente por via bucal. El tratamiento fracaso en 24 (18.2 por ciento) de los casos. La evaluacion de los resultados confirma las ventajas del metodo por su facilidad de aplicacion, ausencia de complicaciones por venoclisis, participacion de los padres, acortamiento de estancia hospitalaria y bajo costo. En consecuencia, es imperativo que este metodo se implante en todos los niveles de la atencion medica, no solamente para el tratamiento de la deshidratacion, sino para la prevencion de la misma durante el curso de la gastroenteritis, ya que las enfermedades diarreicas continuan siendo el motivo mas frecuente de hospitalizacion y una de las causas de mayor mortalidad en la poblacion infantil de nuestro pais