Individual differences in the recovery of the hypothalamic-pituitary-adrenal axis after termination of exposure to a severe stressor in outbred male Sprague-Dawley rats

Individual differences in the speed of recovery of the hypothalamic-pituitary-adrenal (HPA) axis response to immobilization in wooden boards (IMO) were studied in two experiments using a normal population of two months old male outbred Sprague-Dawley rats. In a first experiment, rats were subjected to 2 h IMO and were sampled, together with a group of control rats, at various times by the tail-nick procedure. Rats were divided into three groups depending on plasma corticosterone levels observed 2 h after termination of exposure to IMO: fast recovery (FR), intermediate recovery (IR) and slow recovery (SR). When the samples obtained at different times were classified in function of the three groups obtained at 2 h post-stress, no differences among groups were observed just after IMO. However, in the morning on the day after stress, all IMO rats showed higher plasma corticosterone levels than controls, but SR rats showed higher levels than FR rats, whereas IR rats were in between. Neither ambulatory activity in the open-field nor behaviour in the plus-maze was related to the HPA responsiveness to IMO. In a second experiment, there were no between-groups differences in ACTH and corticosterone levels obtained just after IMO. However, at 2 h, post-stress ACTH levels followed the same pattern as corticosterone. These data indicate that individual differences in the speed of recovery of the HPA axis after exposure to a severe stressor are not related either to individual differences in fear/anxiety or to the HPA response during exposure to the stressor. These individual differences in the capability to terminate the activation of the HPA axis after stress might be related to individual differences in the predisposition to develop stress-induced pathology.

Determination of trace amounts of lead in mussels by flow-injection flame atomic-absorption spectrometry coupled with on-line minicolumn preconcentration

A minicolumn packed with poly(aminophosphonic acid) chelating resin incorporated in an on-line preconcentration system for flame atomic-absorption spectrometry was used to determine ultratrace amounts of lead in mussel samples at microg L(-1) level. The preconcentrated lead was eluted with hydrochloric acid and injected directly into the nebulizer for atomization in an air-acetylene flame for measurement. The performance characteristics of the determination of lead were: preconcentration factor 26.8 for 1 min preconcentration time, detection limit (3sigma) in the sample digest was 0.25 microg g(-1) (dry weight) for a sample volume of 3.5 mL and 0.2 g sample (preconcentration time 1 min), precision (RSD) 2.3% for 25 microg L(-1) and 2.0% for 50 microg L(-1). The sampling frequency was 45 h(-1). The method was highly tolerant of interferences, and the results obtained for the determination of lead in a reference material testify to the applicability of the proposed procedure to the determination of lead at ultratrace level in biological materials such as mussel samples.

[Serological certification of the interruption of the vectorial transmission of Chagas disease in Chile]

BACKGROUND

In 1999 an International Commission of Experts evaluated the sanitary interventions that started in 1980 to eliminate Triatoma infestans, the biological vector of Chagas disease, to certify if the conditions needed to interrupt the transmission, were achieved.

AIM

To report the data used by the International certification commission to certify the interruption of vectorial transmission of Chagas disease in Chile.

MATERIAL AND METHODS

A comparative evaluation of the prevalence of Trypanosoma cruzi antibodies in children surveyed between 1994 and 1995 and between 1995 and 1999.

RESULTS

In the first period, 5,948 children were surveyed and in the second, 5,069 children were studied. Twenty children (0.4%) were positive for Trypanosoma cruzi antibodies in the second survey. These figures were significantly lower than the 1.1% prevalence detected between 1994 and 1995. In only three of the 20 cases, the transmission through vectors was confirmed, which represents a 99.4% reduction of this way of transmission.

CONCLUSIONS

Based on these findings, the Commission certified that Chile is the second country in Latin America to interrupt the vector transmission of Chagas disease. The successful public health program for Chagas disease will have a positive impact improving the quality of life of rural populations, that are most exposed to the disease.

Validated HPLC method for quantifying permethrin in pharmaceutical formulations

An isocratic HPLC method for permethrin determination in raw material and pharmaceutical presentations as lotion and shampoo has been developed and validated following ICH recommendations. Cis and trans- isomers, impurities and degradation products are well separated. The chromatographic analysis were performed on a 4 microm particle C-18 Nova-Pak (Waters, Madrid, Spain) column (15 x 0.39 cm) kept in a Biorad column oven at 35 degrees C. Mobile phase consisted of methanol--water (78:22, v/v) at a flow rate of 1 ml/min. UV detection was performed at 272 nm and peaks were identified with retention times as compared with standards and confirmed with characteristic spectra using the photodiode array detector.

Mycobacterium avium infection in an ostrich (Struthio camelus)

Acid-fast organisms were identified by histopathology of granulomatous lesions in an ostrich (Struthio camelus). The organisms were grown in Herrold's egg media with and without mycobactin and identified as Mycobacterium avium. An agar gel immunodiffusion (AGID) test for Mycobacterium avium paratuberculosis was performed for detection of antibody for M. avium in this infected ostrich and seven other ostriches that were in contact. The results of the AGID were consistent with the pathologic diagnosis of mycobacteriosis and the isolation of M. avium in the affected ostrich.

Effect of internal carotid artery occlusion on vertebral artery blood flow: a duplex ultrasonographic evaluation

The aim of this study was to evaluate the effect of unilateral internal carotid artery occlusion on blood flow volume and blood flow velocities in both vertebral arteries using duplex Doppler ultrasonography in the cervical segment. Forty patients with unilateral extracranial internal carotid artery occlusion confirmed by angiography were studied, and the results were compared with those obtained in 57 age-matched patients in whom cervical duplex ultrasonography showed no abnormalities. We measured the diameter, flow velocities, and blood flow volume in both vertebral arteries, and the side-to-side differences were also calculated. Eleven patients (27.5%) with an occluded internal carotid artery had increased peak systolic velocity in the ipsilateral vertebral artery, and 6 (15%) had increased peak systolic velocity in the contralateral vertebral artery. The mean peak systolic velocity and the mean blood flow volume were statistically greater in the ipsilateral vertebral arteries than in the same-side vertebral arteries of the control group (P < .05). We also detected a mean increase of 14.29% of the net blood flow volume in the vertebral arteries compared with the control group. Patients with extracranial unilateral internal carotid artery occlusion may have a compensatory increase in both the peak systolic velocity and the blood flow volume in both vertebral arteries.

[Minimally deviated adenocarcinoma (malignant adenoma) of the cervix uteri]

Minimal deviation adenocarcinoma (adenoma malignum) is a rare well-differentiated form of invasive cervical adenocarcinoma. Because of its rarity and cytologic changes are subtle there are only a few reports of this pathology, been necessary the realization of large biopsy of the cervical tissue for it histological diagnosis. We made a review in the period 1994-2000, of the clinical, cytological, histological features, treatments and follow-up of 4 patients in the Gynecologic Oncology Department of the University Hospital Vall d' Hebron, Barcelona, Spain.

Secondary metabolites from a Streptomyces strain isolated from Livingston Island, Antarctica

The producing strain Streptomyces sp. 1010 was isolated from a shallow sea sediment from the region of Livingston Island, Antarctica. From the culture broth of this strain naturally active secondary metabolites were isolated identical to phthalic acid diethyl ester (C12H14O4, MW. 222); 1, 3-bis (3-phenoxyphenoxy)benzene (C30H22O4, MW.446); hexanedioic acid dioctyl ester (C22H42O4, MW.370) and the new substance 2-amino- 9, 13 -dimethyl heptadecanoic acid (C19H39NO2, MW.313). These compounds represent diverse classes of chemical structures and provide evidence for the untapped biosynthetic potential of marine bacteria from Antarctica.

Resolution of a mispaired secondary structure intermediate could account for a novel micro-insertion/deletion (387 insA/del 8 bp) in the PYGM gene causing McArdle's disease

We report two siblings with McArdle's disease who are both compound heterozygotes for two non-identical frameshift mutations in the PYGM gene; a previously reported 753 delA in exon 18 and a novel 387 insA/del 8 bp in exon 10. The novel mutation is predicted to result in premature termination of translation 33 amino acids downstream of the site of mutation, potentially encoding a severely truncated protein of 419 amino acids instead of 841 amino acids. The complete lack of myophosphorylase activity observed in muscle derived from one sibling suggests that this mutation has deleterious functional consequences. The underlying mechanism of mutagenesis may have been slipped mispairing mediated by the formation of a Moebius loop-like secondary intermediate.

Evidence that a single exposure to aversive stimuli triggers long-lasting effects in the hypothalamus-pituitary-adrenal axis that consolidate with time

Because of its use as a negative reinforcer in animal studies and its potential pathological impact (e.g. post-traumatic stress disorder and depression), exposure to aversive stimuli is a relevant model for studying CNS plasticity. We present evidence that a single exposure to two predominantly emotional stressors [restraint in tubes and immobilization on wooden boards (IMO)] can modify the response of the hypothalamo-pituitary-adrenal (HPA) axis to a subsequent exposure to the same stressor days later in that a more rapid return to the baseline was observed in the poststress period. In addition, the effect was greater with IMO, the more severe stressor. Using IMO, we have further demonstrated that the effect of a previous single exposure to the stressor (i) increased with days elapsed between the two exposures; (ii) was specific for the previously experienced stressor; and (iii) was mediated via central-mediated effects [corticotropin-releasing factor (CRF) mRNA in the paraventricular nucleus of the hypothalamus]. These data suggest that animals retain memory about a single experience with stressors, resulting in an acceleration of the poststress recovery of the HPA axis that enhances progressively over a period of weeks. The extent to which the present data are relevant regarding post-traumatic stress disorders is unclear, but the study of the HPA response to severe stressors may be suitable for the study of the neurobiological basis of the progressive consolidation of learning over a long period of time (days to weeks).

[What lines of action should the Valencia Society of Family and Community Medicine adopt over the next 4 years?]

OBJECTIVE

To identify the areas of activity in which the Valencia Society of Family and Community Medicine (SVMFyC) should become involved over the next four years.

DESIGN

Qualitative research.Setting. SVMFyC members.

PATIENTS AND OTHER PARTICIPANTS

27 experts belonging to the SVMFyC took part.

INTERVENTIONS

Qualitative consensus-seeking techniques. Reliability and validity of the technique were ensured through triangulation and the selection of experts from among the different professional groups within the SVMFyC.

MEASUREMENTS AND MAIN RESULTS

To determine the recommended lines of action, productivity, spontaneous representativity, intensity of recommendation and degree of agreement were analysed. The priority lines recommended were: defending the MIR path, proposing reforms in undergraduate study plans, watching over the transparency of job selection procedures and the annual OPE selection, promoting the professional degree course, creation of posts for teachers in family and community medicine, defining the size of the population registered with a doctor, proposing an incentives list and studying alternatives to uniform salaries in the form of target-linked remuneration.

CONCLUSIONS

The lines of action recommended by the experts were established.

Multiple mechanisms of immune evasion can coexist in melanoma tumor cell lines derived from the same patient

Progressive tumor growth may be associated with suppression of the immune response. Many different mechanisms may contribute to immune evasion. We investigated some of these mechanisms in melanoma cells lines generated from two patients. These cell lines show a complex pattern of altered HLA expression; however, the resulting phenotype did not satisfactorily explain the simultaneous evasion of T and NK cell cytotoxicity. Two additional alterations have now been detected in these melanoma cell lines: (1) resistance to FAS-induced apoptosis caused by defective FAS gene expression, and (2) constitutive expression of immunosuppressive cytokines. Our results show that several of the major mechanisms for immune evasion may coexist in a single tumor. This suggests that tumor progression may give rise to an extremely resistant phenotype, which may be an impediment to some immunotherapeutic strategies. We hypothesize that the simultaneous presence of several mechanisms involved in tumor immune evasion must be the result of progressive selection of characteristics that are advantageous for tumor survival in a competent host. Our findings do not support the possibility that FASL expression is a common mechanism of evasion of immune response in melanoma cells.

General binocular disorders: prevalence in a clinic population

The purpose of this paper was to study the prevalence of nonstrabismic accommodative and binocular dysfunctions in a clinical population. We examined 265 symptomatic patients who were chosen from an optometric clinic. We performed several tests to diagnose any form of refractive, accommodative or binocular dysfunction. Of the 265 subjects examined, 59 patients (22.3%) had some form of accommodative or binocular dysfunction and required not just the correction of the refractive error but a specific treatment for each of the problems diagnosed. The remaining subjects were classed as having refractive anomalies. The frequency of binocular dysfunctions was 12.9%, and 9.4% for accommodative anomalies. Convergence excess (4.5%) was more prevalent than convergence insufficiency (0.8%) and accommodative excess (6.4%) more prevalent than accommodative insufficiency (3%).

[Valaciclovir in the treatment of initial infection by genital herpes virus: comparative study]

BASIS

To know the therapeutic efficiency in the genital herpes of two drugs: acyclovir and valaciclovir.

METHODS

There were included in the study 142 patients with diagnostic of clinic first episode by genital herpes in two equal groups of 71 patients each one. The distribution in both groups was random to receive one of the following treatment standards: acyclovir 200 mg by verbal each 5 hours, during 7 days; valaciclovir: 500 mg by verbal each 12 hours during 7 days being valued objective and subjective response to the treatment.

RESULTS

The prevailing symptom was the pain (45% and 46.4%), followed by the warmth or burning sensation. The most frequent lesions in both groups were blisters (39.4% and 46.4%). The analysis response to the treatment in relationship to the symptoms as well as in the lesions it could be appreciated that there are not significant differences in the patients treated in both groups (p = 0.3). The adverse effect communicated by the discussed patients were scarce and similar in both groups.

CONCLUSIONS

Both drugs are suitable for the treatment of the genital herpes. The advantage observed with the valaciclovir is the dosing comfort and the facility of completing the treatment.

[Usefulness of the blink reflex in a case of brainstem neuro-Behcet's disease]

INTRODUCTION

Brainstem is the most frequently affected structure in neurobehçet disease. Brainstem auditory evoked responses (BAER) and magnetic resonance imaging (MRI) have been employed in early diagnosis of the disease. We present here a case of neurobehçet disease which brainstem lesion was suspected by blink reflex and corroborated by MRI. BAER were normal in this case.

CLINICAL CASE

The patient was a woman, 49 years old, diagnosed from Behçet's disease. Clinical symptoms consisted of dizziness, headache, nausea, vomiting and bilateral tinnitus preceded by fever in the previous days. Neurological examination showed increased tendon reflexes and adiadochokinesis. Cerebrospinal fluid was inflammatory but aseptic. Computerised tomography and BAER were normal. Blink reflex recording showed abnormalities after the stimulation of the right supraorbital nerve in R2 component, ipsilateral and contralateral, the remainder components being normal. This finding was compatible with a lesion in the spinal tract-nucleus of the right trigeminal nerve. Cranial MRI showed several areas of high signal intensity in protuberancial calotte and spinal tract-nucleus of the trigeminal nerve. The patient improved after prednisone and chlorambucil combined therapy. Serial blink reflex studies were normal, while the patient was asymptomatic.

CONCLUSION

These results indicate that determination of blink reflex together with BAER may be of help in the evaluation of a more extensive area of the brainstem in neurobehçet's disease, even in absence of trigemino-facial symptomatology. Early diagnosis is important because of neurobehçet's morbi-mortality.

Safety and immunogenicity of a paediatric presentation of an influenza vaccine

BACKGROUND

Flu vaccination in otherwise healthy infants and young children is important to prevent severe disease, as well as to control epidemic spread of influenza infection.

AIMS

To examine the safety and immunogenicity of a paediatric presentation of a purified, inactivated, triton split influenza vaccine.

METHODS

Two doses of the vaccine, provided in prefilled syringes of 0.25 ml, were administered, one month apart, to 67 children under 3 years of age.

RESULTS

Nine cases of immediate reaction to vaccination (macules/papules) were observed after the second injection only. During the study period, 9% of children experienced at least one delayed local reaction, and 28% of children presented at least one systemic reaction. Almost all reactions were mild and transient. Immunogenicity results surpassed the European Community recommendations for a 0.50 ml dose of vaccine in adults.

CONCLUSION

This paediatric formulation of inactivated flu vaccine appears safe and immunogenic in children from 6 months to 3 years of age; the convenient presentation in a prefilled syringe of 0.25 ml volume will facilitate administration of the dose recommended for young children.

Clinical evaluation of an in-house IS6110 polymerase chain reaction for diagnosis of tuberculosis

The aim of this study was to clinically validate a heminested polymerase chain reaction (PCR) method, based on the IS6110 insertion segment of Mycobacterium tuberculosis complex, for the diagnosis of tuberculosis. Samples of pulmonary, extrapulmonary and blood origin were collected prospectively from 331 patients. All samples were processed to detect acid-fast bacilli by direct stain, culture and PCR. The gold standard comparison was a clinically based final case definition of tuberculosis corresponding to group 3 of the American Thoracic Society's classification system. The sensitivities of stain, culture and PCR were 41%, 65% and 59%, respectively. Overall specificity exceeded 97% for all techniques. The combination of PCR and direct stain achieved a sensitivity similar to that of culture alone. The PCR method detected 74 of 95 (78%) culture-positive results. In a hospital setting, PCR could be a useful, reliable tool for diagnosis of tuberculosis and may be introduced as a complementary routine diagnostic laboratory method.

Rapid and complete extraction of phenols from olive oil and determination by means of a coulometric electrode array system

Extraction methods to determine olive oil phenols are not exhaustive. A procedure to test their effectiveness, based on the treatment of the extracted oil with 2 N HCl followed by analysis of phenols in the aqueous phase, has been developed. It was concluded, using this test, that 15-40% of phenols remained unextracted when the liquid/liquid extraction method with 80% methanol was applied. Solid phase extraction (C(18) cartridge) succeeded in retaining most of the phenols in the cartridge, but the recovery yield from the sorbent material was low. However, a new extraction method, based on the use of N,N-dimethylformamide (DMF) as an extraction solvent, achieved a complete extraction of phenols from oils. The proposed method requires a lower amount of oil, solvents, energy, and labor than the traditional ones. Because of the low concentration of phenols in the DMF extract, the highly sensitive electrochemical detector (EC) technique was studied. All of the phenols detected by the traditional UV detectors were also detected by EC using a coulometric array system. A rapid and complete analytical methodology of phenols in olive oil has been proposed based on coupling DMF extraction and EC detection.

Surfactant protein genetic marker alleles identify a subgroup of tuberculosis in a Mexican population

Pulmonary surfactant and its components are essential for normal lung function and are involved in local host defense. Surfactant protein (SP)-A and SP-D bind to and modulate phagocytosis of Mycobacterium tuberculosis by macrophages. Frequency comparisons of SP marker alleles in tuberculosis patients and healthy control subjects (tuberculin-skin test positive or general population) were performed. Regression analyses of the tuberculosis and the tuberculin-skin test positive groups revealed, on the basis of odds ratios, tuberculosis susceptibility (DA11_C and GATA_3) and protective (AAGG_2) marker alleles. Similarly, between tuberculosis patients and general population control subjects, susceptibility 1A(3), 6A(4), and B1013_A and protective AAGG_1, and AAGG_7 marker alleles were observed. Moreover, interactions were seen between alleles 6A(2) and 1A(3) (P=.0064) and between 1A(3) and B1013_A (P=. 036). The findings indicate a possible involvement of SP alleles in tuberculosis pathogenesis.

Shape of the 8B alpha and neutrino spectra

The beta-delayed alpha spectrum from the decay of 8B has been measured with a setup that minimized systematic uncertainties that affected previous measurements. Consequently the deduced neutrino spectrum presents much smaller uncertainties than the previous recommendation [J. N. Bahcall et al., Phys. Rev. C 54, 411 (1996)]. The 8B nu spectrum is found to be harder than previously recommended with about (10-20)% more neutrinos at energies between 12-14 MeV. The integrated cross sections of the 37Cl, 71Ga, 40Ar, and Super-Kamiokande detectors are, respectively, 3.6%, 1.4%, 5.7%, and 2.1% larger than previously thought.

A mitochondrial tRNA(Lys) gene mutation (T8316C) in a patient with mitochondrial myopathy, lactic acidosis, and stroke-like episodes

We studied a patient with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes who had morphologically and biochemically abnormal muscle mitochondria. Molecular analysis revealed a T8316C transition in the mitochondrial DNA tRNA(Lys) gene. The mutation was homoplasmic in muscle from the proposita, heteroplasmic in her blood, and still less abundant in blood from her asymptomatic maternal relatives. The T8316C mutation affects a highly conserved base pair and was not found in controls, thus satisfying the accepted criteria for pathogenicity. Our data document the genetic heterogeneity in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, underlining that the same syndrome may be associated with mutations of different genes.

Platelet-derived growth factor and epidermal growth factor play a major role in human colonic fibroblast repair activities

BACKGROUND AND AIMS

Ulceration is a common feature of inflammatory bowel diseases, where subepithelial cell growth is frequently necessary for resolution. In order to further understand the role of colonic fibroblasts in this process, we have used an in vitro model of wound repair to study the response of human colonic fibroblasts to several growth factors expressed in colonic tissues.

METHODS

Proliferation was determined by [(3)H]thymidine incorporation into DNA in subconfluent fibroblast cultures. In vitro wound repair was determined in confluent fibroblast monolayers after mechanical denudation. The presence of growth factors secreted by fibroblasts was studied in conditioned medium by heparin affinity chromatography and immunodetection with specific antibodies.

RESULTS

Serum and platelet-derived growth factor (PDGF-BB) induced a dramatic increase in both colonic fibroblast proliferation and closure of wounded cell monolayers. Epidermal growth factor (EGF) stimulated both fibroblast activities, but the effect was less potent. However, colonic fibroblasts did not respond to transforming growth factor-beta(1). Conditioned medium stimulated fibroblast proliferation and wound repair activity, which was reverted by the addition of suramin. Furthermore, a PDGF-like factor was isolated from colonic fibroblast-conditioned medium.

CONCLUSIONS

EGF and PDGF-BB promote human colonic fibroblast-dependent wound repair activities. Human colonic fibroblasts may exert an autocrine regulation via the production of growth factors.