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Biomedical subjects

P Peña

Publications and source records attributed to P Peña.

At least 19 recordsLinked to original sources
PubMed2004

Critical assessment of the methods used for detection of bacterial translocation.

AIM: Bacterial translocation (BT) can be demonstrated by blood and lymph node cultures and also by polymerase chain reaction (PCR) detection of DNA of enteric bacteria. Aiming at investigating BT after gastrointestinal operations we assessed it on two endpoints after ischemia-reperfusion (IR) or sham operation (SO). METHODS: 2 groups of 200-g Brown Norway male rats were treated as follows: SO animals ( n=12) had laparotomy alone and IR animals ( n=12) had successively 15 min clamping of the portal vein and the mesenteric artery. Half the animals in each group were killed on postoperative (p.o.) day 2 the other half on p.o. day 7. Under sterile conditions regional lymph nodes and vena cava and portal vein blood samples were recovered and cultured for aerobes and anaerobes. Escherichia coli beta-galactosidase DNA was assessed in blood samples by PCR. The findings in the two groups were compared by means of chi(2) tests. RESULTS: Post-hepatic (peripheral blood) BT was detected by cultures of gram-negative bacteria in 16% and 0% of SO and IR animals, respectively, on p.o. day 2 and in 16% and 50% on p.o. day 7. These differences were not significant (ns). E. coli DNA was found in one SO rat. Pre-hepatic BT (portal blood and/or lymph nodes) of gram-negative bacteria was found in 16% and 33%, respectively, on day 2 and in 16% and 16% on day 7 (ns). However, if gram-positive cultures were taken into account, the figures were 66% and 66% on day 2 and 66% and 83% on day 7 (ns). No anaerobes could be cultured. CONCLUSIONS: (1) BT is frequent in surgically manipulated animals. (2) To limit the assessment of BT to Enterobacteriaceae is probably misleading, since consistent amounts of gram-positive bacteria are found in the pre-hepatic territory. (3) PCR tests limited to E. coli DNA alone are likely incomplete. (4) Short periods of vascular clamping do not increase BT on the two endpoints selected in comparison with SO animals.

Animals↗
PubMed2004

Detection of a CBG-like protein in human Fallopian tube tissue.

The acrosome reaction (AR), a modified exocytotic process, is prerequisite for successful mammalian fertilization. The protein component that is responsible for the AR-inducing activity of human follicular fluid, has been found to be immunologically identical with corticosteroid-binding globulin (CBG), which is well characterized and serves as a transport protein for progesterone and cortisol in the plasma. Our findings have shown that the CBG-like protein is expressed by endothelial cells of the Fallopian tube depending on the hormonal cycle. In the culture medium of human epithelial tubal cells, the CBG-like protein was detected by Western blot analysis. The protein was also found in biologically active form in human tubular fluid. Our investigations strongly indicate that human Fallopian tube cells actively express and secrete a CBG-like progesterone-binding protein, which might play a role in the in vivo modulation of human sperm AR.

Acrosome Reaction↗
PubMed2004

Alpha-glucosidase in the human epididymis: topographic distribution and clinical application.

Alpha-glucosidase activity (EC.3.2.1.20) is present in human seminal plasma, and the neutral form of the enzyme originates almost exclusively from the epididymis. In this study, the specific immunocytochemical location of alpha-glucosidase in the human epididymis was evaluated using a polyclonal antibody. Furthermore, a spectrophotometric assay was employed to assess epididymal obstruction in infertile patients. The enzymatic activity of alpha-glucosidase free of prostate isoform (AGFPI) was determined spectrophotometrically at 405 nm. According to AGFPI activity, patients with leucocytospermia, oligozoospermia and azoospermia were recorded as having normal values or low values indicating epididymal obstruction. Specific immunochemistry staining was demonstrated in the cytoplasmic cells at the epithelial level, in the transition area and in the efferent ducts. The values of the three groups and the control were as follows (mean +/- SEM): normozoospermia (control): 20.2 +/- 1.4 mU ml(-1); azoospermia: normal value: 17.6 +/- 2.2 mU ml(-1), low value: 7.4 +/- 1.8 mU ml(-1); oligozoospermia: normal value: 22.3 +/- 2.5 mU ml(-1), low value: 7.3 +/- 0.7 mU ml(-1); leucocytospermia: increase value: 38.9 +/- 3.7 mU ml(-1), low value: 11.1 +/-1.3 mU ml(-1). This study suggests that determination of alpha-glucosidase might be helpful to evaluate functions of the epididymis and particularly to exclude epididymal obstruction.

Adult↗
PubMed2003

Achromobacter xylosoxidans bacteremia: a 10-year analysis of 54 cases.

Fifty-four cases of Achromobacter xylosoxidans bacteremia diagnosed over a 10-year period in patients from 2 months to 87 years of age were reviewed. Fifty-two episodes were nosocomial. The most frequent underlying condition was neoplasm (solid or hematological). The source of infection was a contaminated intravenous catheter in 35 patients (60%) and pneumonia in 6 patients. Eight (15%) patients died. The only risk factors significantly associated with mortality were age over 65 years and neutropenia. The results of in vitro susceptibility studies of the isolates showed that antibiotic therapy with antipseudomonal penicillins or carbapenems would be a reasonable choice. An epidemiological study conducted in the hemodialysis unit showed Achromobacter xylosoxidans in tap water and on the hands of two healthcare workers but not in the hemodialysis systems. Patients were probably contaminated when healthcare workers manipulated the intravenous catheters without wearing gloves.

Adolescent↗
PubMed2001

Evaluation of the acrosome reaction in human spermatozoa: comparison of cytochemical and fluorescence techniques.

The acrosome reaction, which is essential for fertilization, includes fusion and vesiculation of the plasma membrane with the outer acrosomal membrane of spermatozoa, thereby releasing the acrosomal content. Determination of the ability of spermatozoa to undergo the acrosome reaction has proved to be a useful parameter in evaluation of infertile patients. The objective of this study was to compare cytochemical techniques, such as double stain (Giemsa/trypan blue) and triple stain (Bismarck brown/rose bengal/trypan blue), with a fluorescence method using Pisum sativum agglutinin fluorescein conjugate and Hoechst dye N degrees 33258 (double fluorescence). Whereas the cytochemical methods are easy to perform in general laboratories, the fluorescence technique requires special and costly instrumentation. In semen obtained from fertile donors, spermatozoa were selected by the swim-up technique and the acrosome reaction was induced by incubation at low temperature. The percentages of vital and acrosome-reacted spermatozoa were determined after incubation at 4 degrees C and at room temperature. No statistically significant difference was found between double fluorescence (viability 86.3%, acrosome reaction 14.7%) and triple stain (viability 85.3%, acrosome reaction 17%) (P > 0.05). On the other hand, the double stain technique showed different values for viability (70.3%) and acrosome reaction (42.5%) (P < 0.05). In conclusion, triple stain yielded results similar to those obtained by the fluorescence technique in evaluating the acrosome reaction and can therefore easily be used in general or research laboratories.

Acrosome Reaction↗
PubMed2001

[Effects of proteolytic enzymes and sexual abstinence on alpha glucosidase biochemical quantification in human seminal plasma].

BACKGROUND: alpha-glucosidase is found in human seminal plasma as an acid form, located in accessory glands, and as a neutral form secreted almost exclusively by the epididymis. Quantification of alpha-glucosidase activity is a marker of the secretory function of the epididymis and indemnity of the sperm transport pathway. AIM: To obtain reference values for alpha-glucosidase in normal samples of seminal plasma, to evaluate its behavior in serial samples and to determine the effect of proteolytic enzymes. MATERIAL AND METHODS: Fifty donors, with normal semen analysis according to the criteria of the World Health Organization, were evaluated. For the study with alpha-quimotrypsin, 0.1 to 10 mg/ml of the enzyme was added to the seminal plasma from a group of donors. alpha-glucosidase was also measured in semen obtained from nine patients at different time intervals. RESULTS: Normal alpha-glucosidase values ranged from 14.52 to 25.69 microU/ml. Concentrations up to 10 mg/ml of alpha-quimotrypsin (10 times of that usually used in the liquefaction of the semen) did not alter the quantification of alpha-glucosidase. Serial determinations revealed oscillations in their magnitude, which stayed in each patient's characteristic range. However a subgroup presented a marked reduction of the activity of alpha-glucosidase as the abstinence diminished (40%). CONCLUSIONS: Evaluation of alpha-glucosidase in seminal plasma gives reliable information of the secretor state of the epididymis and especially replaces invasive methods used to evaluate the indemnity of the spermatic transport from the epididymis to the anterior urethra.

Adult↗
PubMed2000

137Cs and relationships with major and trace elements in edible mushrooms from Mexico.

137Cs and 40K specific activity together with major and trace elements were determined in soil samples and in different edible wild mushroom species collected from a seminatural temperate forest ecosystem located in the central part of the Mexican Volcanic Belt. The activity measurements were made using a gamma-ray spectrometer system with a high purity germanium (HpGe) detector. The major and trace elements were determined using emission spectrography and mass spectrometry, respectively. The aggregated transfer factors for 137Cs were estimated in 30 local mushroom species collected from 1993 to 1999. Differences as large as three orders of magnitude were observed. The contribution of mushrooms for the total 137Cs dietary intake by the local population was estimated to be 37%. Mushrooms also showed to be good accumulators for Rb, Cu, Cs and Se.

Agaricales↗
PubMed2000

[Use of midodrine and frozen semen to treat semen transport disturbances. Report of 2 cases].

Retrograde ejaculation severely compromises male fertility. The use of sympathicomimetics for the treatment of this condition has poor results, except in patients with partial retrograde ejaculation, whose semen has a higher spermatozoa concentration. The semen of two patients with partial retrograde ejaculation was collected and frozen after the injection of a sympathicomimetic (Midodrine). The frozen/thawed samples were mixed with fresh semen recently ejaculated to obtain a minimal number of motile spermatozoa, and used for intrauterine insemination (> de 1 x 10(6) motile spermatozoa/ml). In both cases, pregnancies that developed satisfactorily, were obtained.

Adult↗
PubMed2000

[Variability determination in chromatin condensation and seminal alpha glucosidase with relation with the spermiogram].

BACKGROUND: Sperm functional tests as an addition to semen analysis have been used to study the fertilization ability of spermatozoa. Besides the usual variability of the seminal analysis an individual variability in the results of functional tests has been recently found. AIM: To evaluate in a three months period, the individual variability of sperm parameters and sperm maturation using the chromatin condensation test and epidydime a-glucosidase (that allows to discriminate obstructive processes). MATERIAL AND METHOD: The evaluation was carried out in two donors (12 samples) apparently in good health. One of them presented evident semen analysis alterations (donor 1) and the other was considered normal under the WHO standards (donor 2). RESULTS: The averages for donor 1 were: Sperm count 24 x 106 sperm/ml (range 10-58 x 106 sperm/ml), morphology 31.8% (range 30-35%), total motility 33% (range 20-42%), sperm maturation 38% (range 28-78%), a-glucosidase 8.65 (U/ml (range 5-10 (U/ml). The averages for donor 2 were: Sperm count 96 x 106 sperm/ml (range 50-140 x 106 sperm/ml), morphology 32.2% (range 30-35%), total motility 69% (range 58-78%), sperm maturation 17% (range 7-30%), a-glucosidase 36.9 (U/ml (range 20-82 (U/ml). CONCLUSIONS: These results show that significant variations can be found in the sperm parameters and in seminal plasma a-glucosidase; however these variations are generally maintained at the normal or abnormal ranges for each individual, except the sperm morphology that was constant and with low variation in both donors. The determination of the chromatin condensation in the semen analysis gives an additional information about the grade of sperm maturation and would be of great value for differentiating between sperm samples that show similar morphology values.

Adult↗
PubMed1999

Groundwater flow system in the valley of Toluca, Mexico: an assay of natural radionuclide specific activities.

Natural radionuclides and physicochemical parameters have been evaluated in groundwater samples from boreholes belonging to the drinking water supply system of the Toluca City, Mexico. The results obtained for radon and radium, together with the physicochemical parameters of the studied samples, indicate a fast and efficient recharge pattern. The presence of a local and a regional groundwater flows was also observed. The local flow belongs to shallower water, recognized by its low radon content and dissolved ions, as compared with the regional, deeper groundwater flow with a longer residence time.

Fresh Water↗
PubMed1998

[Septicemia associated with central venous catheterization in a children's hospital. A multivariate study].

BACKGROUND: The blood stream infections (BSI) are the principal nosocomial infection in the child hospitals. In this study we estimate the incidence of BSI associated with central venous catheterization, and estimate different risk and protective factors, through a multivariate study. MATERIAL AND METHODS: The study have followed in a prospective way during 6 months all the children with central venous catheterization (489 catheters), from the moment of insertion until withdrawal, collecting various data previous to the development of the infection: place of insert, type of catheter, duration, clinic information, microbiology, and the treatments administered through the catheter. In was accomplished an multivariate analysis with logistic regression, for two principal effect variables, the catheter colonization and the catheter related BSI. RESULTS: The incidence of catheter related BSI was 5.5% and for local infection 11.2%. The density of incidence was 3.15 and 6.42 for each 1,000 catheters-day, respectively. The logistic regression model included: colonization of the skin in the insertion point > 15 colonies, days with antibiotics through catheter, use of lipidic parenteral solutions and fever, previous to the infection. The area under the ROC curve was 0.72. CONCLUSIONS: In children with septicemias associated with central catheterization the predictors or sentry criterion for the decision on when to withdraw a catheter are colonization (> 15 colonies) of the insert point, together with the use of lipidic parenteral solutions or extended antibiotic treatment.

Age Factors↗
PubMed1998

The transcription factor GHF-1, but not the splice variant GHF-2, cooperates with thyroid hormone and retinoic acid receptors to stimulate rat growth hormone gene expression.

The rat growth hormone (GH) promoter was significantly activated in non-pituitary cells by the expression of unliganded trioodothyronine (T3) and retinoic acid (RA) receptors. Furthermore, a strong ligand-dependent activation was found in the presence of the pituitary-specific transcription factor GHF-1. When compared with GHF-1, the splice variant GHF-2 showed a decreased ability to bind the cognate site in the GH promoter. As a consequence, expression of GHF-2 had little stimulatory effect on the GH promoter and did not show cooperation with T3 or RA receptors even in the presence of ligands. Furthermore, over-expression of GHF-2 inhibited the response to T3 and RA in pituitary cells. These results show that alternative splicing of the GHF-1 gene gives rise to two isoforms that differ in their transactivating properties and in their ability to synergize with the nuclear thyroid hormone and retinoic acid receptors on GH gene expression.

Alternative Splicing↗
PubMed1998

A direct protein-protein interaction is involved in the cooperation between thyroid hormone and retinoic acid receptors and the transcription factor GHF-1.

The nuclear receptors for thyroid hormone (TRs) and retinoic acid (RARs and RXRs) cooperate with the pituitary-specific transcription factor GHF-1 to activate the rat growth hormone (GH) gene. The GH promoter contains a hormone response element (HRE), which binds TR/RXR and RAR/RXR heterodimers, located close to two binding sites for GHF-1. GHF-1 inhibits binding of TR/RXR and RAR/RXR heterodimers to an isolated HRE. Similarly, the receptors inhibit binding of GHF-1 to its cognate site. These results suggest the existence of direct protein to protein interactions between the receptors and the pituitary transcription factor. This was confirmed by in vitro binding studies with GST fusion proteins, which demonstrated a strong association of GHF-1 with RXR and a weaker interaction with RAR and TR. GHF-1 and the receptor heterodimers form a ternary complex with a fragment of the rat GH promoter, which contains binding sites for both, and GHF-1 increases receptor binding to the promoter when present in limiting conditions. These results suggest that the synergistic activation of the rat GH gene involves protein-DNA interactions as well as a physical association between the nuclear receptors and the pituitary-specific transcription factor GHF-1.

Animals↗
PubMed1997

[Viridans streptococci isolated from cerebrospinal fluid. Clinical significance of 9 cases].

Viridans streptococci (VS) are often isolated from cerebrospinal fluid (CSF). However, the significance of such isolates is poorly understood. In the present study we carry out a retrospective analysis of 9 patients in whom VS were isolated from CSF during a 1-year period at La Paz Hospital. Two patients (22.2%) had meningitis diagnosed through clinical, laboratory and bacteriologic findings. Both patients had predisposition diseases (previous difficult spinal tap, ventriculo-peritoneal shunt). The other isolations were considered as contaminants. Three patients (33.3%) with no VS meningitis had other different serious disease (sepsis without bacteriologic confirmation). VS are isolated with relative frequency from CSF, although they cause meningitis in less than one-quarter of the cases (those who have a predisposition disease). In the other cases, VS are isolated as contaminants of CSF and other disease should be search as cause of patient symptoms.

Adolescent↗
PubMed1997

Destructive herpetic whitlow in AIDS: report of three cases.

Herpes simplex virus infection in immunocompromised individuals, including AIDS patients, is characterized by its tendency for atypical presentations and unusual locations, often resulting in delayed diagnosis and treatment. Three HIV-infected patients who developed prolonged cutaneous lesions of the fingers are presented. These lesions were unmodified by previous antibiotic treatment, and rapidly progressed to the complete destruction of nail structures in two patients. Viral culture confirmed the diagnosis of herpetic whitlow in all cases, and treatment with oral acyclovir resulted in complete recovery. Surgical treatment was not necessary.

AIDS-Related Opportunistic Infections↗
PubMed1996

Hypophysial and extrahypophysial projections of the neurosecretory system of cartilaginous fishes: an immunocytochemical study using a polyclonal antibody against dogfish neurophysin.

Immunocytochemistry using antibodies against the neurohypophysial nonapeptides has given equivocal results regarding relevant aspects of the classical neurosecretory system of elasmobranchs. The lack of antibodies reacting with the elasmobranch neurophysins (Nps) has prevented the study of this neurosecretory system by Nps immunocytochemistry. This led us to purify Nps from Scyliorhinus canicula, and to use them to raise a polyclonal antibody. This antibody reacted strongly with the elasmobranch neurophysin neurons, revealing their most delicate and distant hypophysial and extrahypophysial projections. A detailed mapping of the neurosecretory system of five elasmobranch species (Etmopterus spinax, Squalus acanthias, Scyliorhinus canicula, Galeus melanostomus, Raja radiata) and one holocephalian species (Hydrolagus colliei) was performed. In elasmobranchs, the magnocellular neurophysin cells formed a distinct preoptic nucleus, whereas in Hydrolagus the immunoreactive cells were scattered. Distinct parvicellular neurophysin cells were present in the preoptic nucleus. In Raja the nucleus "O" contained parvicellular Nps-immunoreactive neurons. The findings at the pituitary level point to the possibility that neurophysin neurons, in addition to releasing nonapeptides into the systemic capillaries of the neural lobe, also participate in the regulation of the function of the rostral, medial and intermediate lobes of the adenohypophysis by a dual mechanism, i.e., a neurovascular pathway and a direct neural input. The extrahypophysial projections of the neurophysin neurons were highly developed to a degree not comparable to any other vertebrate group. The targets of these projections were located in the telencephalon, diencephalon and hindbrain. The evolutionary and functional implications of this phenomenon are discussed.

Animals↗
PubMed1996

[Epilepsy and dementia. An atavistic association].

We carried out a brief historical review as to the meaning of the association between epilepsy and dementia and of 'epileptic dementia'. We also reviewed the literature published in the last decade on this theme, analyzing whether chronic recurrence of epileptic fits brings about cognitive deterioration. We concluded by affirming that 'epileptic dementia' was a mixed bag containing numerous diseases and syndromes with symptoms of both. Only exceptionally could epileptic fits bring on cognitive deterioration and this usually only slight. A great many factors and not just recurrent epileptic fits determine cognitive prognosis in epileptics.

Cognition Disorders↗