Comparative Anatomy of the Forearm and Hand of Wildcat (Leopardus geoffroyi), Ocelot (Leopardus pardalis) and Jaguar (Panthera onca)

Introduction The thoracic limbs of cats facilitate jumping and represent one of their main ways for pursuing and capturing prey. The main muscles and nerves involved in these activities are present in the region of the forearm and of the hand. The scant anatomical reference availabe on South American cats species justifies the present comparative study.

Materials and Methods The forelimbs of wildcat, ocelot and jaguar wild felines were fixed. Images of the dissected limbs were captured using a digital camera. Measurements were made using a caliper.

Results The long and short heads of the extensor carpi radialis muscle of the ocelot and of the jaguar showed a great development in comparison with those of the wildcat. The flexor digitorum profundus muscle in the three felines is formed by five heads. In the jaguar, the radial or deep head presented two sesamoid bones. The brachioradialis muscle of the jaguar and of the ocelot is inserted medially at the distal end of the radius and at the proximal row of the carpus by a thick and flattened tendon. The pronator teres muscle of the jaguar extended to the carpal region. In the wildcat and in the ocelot, this muscle was less developed

Conclusions The main variations observed between the forearms and the hands of these South American cats were found between the supinator and the pronator muscles, presenting a variation in the size of their bellies and tendons. Our study of the muscular characteristics represents a contribution to the homologies and differences of the forearm and hand muscles of each of these species of felines.

Prevalence of Sarcopenia in Community-Dwelling Chilean Elders According to an Adapted Version of the European Working Group on Sarcopenia in Older People (EWGSOP) Criteria

BACKGROUND

Sarcopenia is the progressive loss of mass and skeletal muscle strength and has serious consequences on older people's health. The Chilean older population has a high life-expectancy, but the prevalence of functional dependence is also high.

OBJECTIVE

To determine the prevalence of sarcopenia in Chilean older adults and its relationship with age, gender, and body mass index (BMI).

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

1,006 non-disabled, community-dwelling subjects aged 60 years or older living in Santiago.

MEASUREMENTS

Anthropometric measurements, handgrip strength, physical performance tests, and dual-energy-x-ray-absorptiometry (DXA) scan were performed. Sarcopenia was defined using the algorithm of the European Working Group on Sarcopenia in Older People (EWGSOP). Muscle mass was measured with DXA scan; skeletal muscle mass index (SMI) and hand dynamometry were defined with cut-off points obtained for the Chilean population. For a 3m walking speed we used the cut-off point of the EWGSOP definition. Nutritional status and obesity were defined according to World Health Organization standards. Association between sarcopenia and age, gender, BMI and lean/fat mass ratio was estimated by logistic regression models.

RESULTS

The prevalence of sarcopenia was 19.1% (95%CI: 16.8%-21.8%), similar in men and women. There was an increasing trend of sarcopenia by age group and a decreasing trend with nutritional status. After logistic regression, sarcopenia was positively associated with age (OR=1.10; 95%CI:1.06-1.15) and falls (OR=1.83; 95%CI:1.07-3.15) and negatively associated with overweight (OR=0.31; 95%CI:0.16-0.59), obesity (OR=0.02; 95%CI:0.004-0.11), lean mass/fat mass ratio (OR=0.69; 95%CI:0.48-0.9997), knee height (OR=0.78; 95%CI:0.68-0.89) and calf circumference (OR=0.87; 95%CI:0.77-0.97).

CONCLUSIONS

The total prevalence of sarcopenia was 19.1% increasing with age reaching 39.6% in people of 80 or more years of age. A negative association of sarcopenia with overweight, obesity and lean/fat mass ratio was observed. Although the high prevalence of obesity (35.9%), only 2% of obese people were sarcopenic.

Evaluación de diferentes niveles de inclusión de plantas nativas de sabanas inundables sobre una dieta basal de Brachiaria humidicola y su efecto sobre la producción de metano in vitro

Se evaluó el efecto sobre la producción de metano de la inclusión creciente (25, 50 y 75 %) de cinco plantas nativas de sabanas inundables (Senna occidentalis, Enterolobium schomburgkii, Galactia jussiaeana, Belencita nemorosa y Ambrosia peruviana), sobre una dieta base de Brachiaria humidicola. Los tratamientos fueron incubados anaeróbicamente con fluido ruminal a 39°C por 24 h y después del proceso de fermentación, se determinó la producción de gas, metano, ácidos grasos volátiles (AGV), amonio y degradación de la materia seca (MSD). La inclusión en la dieta de 50 y 75% de todas las plantas, incrementaron el contenido de amonio ruminal, con valores entre 189 - 282 mg/L. Ninguna de las plantas modificó la concentración de AGVT (44-62 mmol/L). La producción de metano no se redujo significativamente con ningún tratamiento (p>0,05), aunque con S. occidentalis (75%) este parámetro fue inferior en un 18%, además, se incrementó la MSD y los niveles de butirato, isobutirato y valerato. Con E. schomburgkii (75%), la metanogénesis también se redujo en un 15%, sin embargo, este efecto estuvo acompañado de una disminución en la MSD y producción de gas. En conclusión, ninguna de las plantas mostró potencial para reducir la producción de metano, no obstante, las especies se convierten en alternativas nutricionales útiles para complementar el aporte proteico de la dieta en los sistemas ganaderos ubicados en condiciones de sabanas inundables.

Current practice in Latin America of flexible ureterorenoscopy with laser for treating kidney stones

INTRODUCTION

The use of flexible ureterorenoscopy for treating kidney stones has increased in recent years, with considerable worldwide variation in the surgical technique and indications.

OBJECTIVES

To determine the current practice, technique variations, use and indications of flexible ureterorenoscopy for treating kidney stones in Latin American.

METHODS

We sent (by email and web link) an anonymous questionnaire with 30 questions on flexible ureterorenoscopy for treating kidney stones to Latin American urologists from January 2015 to July 2015. We collected the responses through the Survey Monkey system.

RESULTS

A total of 283 urologists in 15 Latin American countries participated (response rate, 10.8%); 254 answered the questionnaire completely; 52.8% were urologists from Mexico and 11% were from Argentina; 11.8% of the responders stated that they performed >100 cases per year; 15.2% considered ureterorenoscopy as the treatment of choice for stones >2cm, and 19.6% performed ureterorenoscopy in single stages for calculi measuring >2.5cm. Some 78.4% use fluoroscopy, 69.1% use a ureteral sheath in all cases, 55.8% place double-J catheters at the end of surgery, 37.3% considered a stone-free state to be 0 fragments, and 41.2% use plain radiography to assess the stone-free condition.

CONCLUSIONS

Most participating urologists consider flexible ureterorenoscopy as the first-choice treatment for stones <2cm; a small percentage of these urologists perform >100 ureterorenoscopies per year. More than half of the urologists routinely used fluoroscopy and ureteral access sheath; the most common method for determining the stone-free state is plain abdominal radiography.

Mini Nutritional Assessment Short-Form: Validation in Five Latin American Cities. SABE Study

OBJECTIVES

To validate the short-form of the MNA (MNA-SF) and the cut-off point of 31 cm for calf circumference (CC) in older people in Latin America.

METHODS

A cross-sectional study was conducted with 5,722 community-dwelling older subjects (range: 60-102 years) in Latin America´s five main cities: Sao Paulo (Brazil), Santiago (Chile), Havana (Cuba), Mexico DF (Mexico) and Montevideo (Uruguay). All participants underwent an interview, which included anthropometric measurements, completing the MNA and obtaining socio-demographic, nutrition and health information. The short-form of the MNA consists of only six questions from the original 18. It has two versions: one using body mass index (BMI) and the second using CC as a surrogate. Cohen's Kappa was calculated to assess the agreement between the MNA and the MNA-SF; diagnostic tests were performed, and Receiver-operating characteristic (ROC) curves were developed. Criterion-related validity was assessed in the Chilean sample.

RESULTS

Both version of the MNA-SF showed high sensitivity and specificity with the MNA, showing good accuracy (0.88), although higher values were estimated for malnutrition and risk of malnutrition in the total sample by sex. The cut-off point of 31 cm for CC showed high sensitivity (74.6-94.4%), specificity (72.6-100%) and good area under the ROC curve (0.87-0.95) when compared with BMI. There was good agreement between MNA and both version of MNA-SF for identifying persons with malnutrition or a risk of malnutrition in the five cities (Kappa coefficient: 0.6193-0.7852).

CONCLUSION

Both versions of the MNA-SF are population-screening tools of easy and fast application, with good accuracy for assessing malnutrition and risk of malnutrition in Latin American older people.

A multicentric study regarding the use of hormone therapy during female mid-age (REDLINC VI)

BACKGROUND

Menopausal hormone therapy (HT) has shown benefits for women; however, associated drawbacks (i.e. risks, costs, fears) have currently determined its low use.

OBJECTIVE

To determine the prevalence of current HT use among mid-aged women and describe the characteristics of those who have never used, have abandoned or are currently using HT. In addition, reasons for not using HT were analyzed.

METHOD

This was a cross-sectional study that analyzed a total of 6731 otherwise healthy women (45-59 years old) of 15 cities in 11 Latin American countries. Participants were requested to fill out the Menopause Rating Scale (MRS) and a questionnaire containing sociodemographic data and items regarding the menopause and HT use.

RESULTS

The prevalence of current HT use was 12.5%. Oral HT (43.7%) was the most frequently used type of HT, followed by transdermal types (17.7%). The main factors related to the current use of HT included: positive perceptions regarding HT (odds ratio (OR) 11.53, 95% confidence interval (CI) 9.41-14.13), being postmenopausal (OR 3.47, 95% CI 2.75-4.36) and having a better socioeconomic level. A total of 48.8% of surveyed women had used HT in the past, but abandoned it due to symptom improvement or being unconcerned; fear of cancer or any other secondary effects were also reported but in less than 10%. Among women who had never used HT, 28% reported the lack of medical prescription as the main reason, followed by the absence of symptoms (27.8%). Among those reporting lack of prescription as the main reason for not using HT, 30.6% currently had severe menopausal symptoms (total MRS score > 16); 19.5% of women were using alternative 'natural' therapies, with 35.1% of them displaying severe menopausal symptoms as compared to a 22.5% observed among current HT users.

CONCLUSION

The use of HT has not regained the rates observed a decade ago. Positive perceptions regarding HT were related to a higher use. Lack of medical prescription was the main reason for not using HT among non-users, many of whom were currently displaying severe menopausal symptoms.

Sandfly saliva of Lutzomyia ovallesi (Diptera: Psychodidae) as a possible marker for the transmission of Leishmania in Venezuela Andes region

BACKGROUND & OBJECTIVES

The saliva of the Phlebotominae is highly immunogenic to the vertebrate host and is a determining factor in the Leishmania infection. The aim of this work was to study the saliva of Lutzomyia ovallesi as a possible risk marker for the transmission of Leishmania.

METHODS

Two populations of L. ovallesi from different geographical areas and subjected to different environmental conditions were compared by geometric morphometry of the wings, by protein profile analysis of salivary glands and by assessing the presence of anti-saliva protein in human sera confronted with laboratory L. ovallesi saliva.

RESULTS

The results showed differences in the isometric size and structure of the wings but no allometric effects. Protein profiles of salivary glands of both the L. ovallesi populations studied were found to be similar, based on 11 protein bands with molecular weights ranging from 16 to 99 kDa. Anti-saliva antibodies were present in human sera, but human sera infected and uninfected with leishmaniasis could not be differentiated.

INTERPRETATION & CONCLUSION

We conclude that the saliva of laboratory-reared L. ovallesi is representative of that of the wild population. It is suggested to study the presence of anti-saliva antibodies in other species of sandflies and mosquitoes.

Gluten-free bread formulated with Prosopis ruscifolia (vinal) seed and corn flours

Vinal (Prosopis ruscifolia) is a wild leguminous tree found widely in the north of Argentina. Like other Prosopis, vinal can grow under extreme temperatures, in poor soils and can tolerate high saline conditions. Taking into account the high protein and gums contents of vinal seeds, a gluten-free bread was developed including them and corn flour. A central composite design involving vinal seed flour/corn starch ratio (X1) and corn flour/corn starch ratio (X2) was used, and second-order models for specific volume (Y1) and bread score (Y2), evaluated by an expert panel, were employed to generate response surfaces. In the optimum zone of response surfaces, a product with higher protein content (5.2 g/100 g) than gluten-free breads found in local commercial markets was obtained. Also, an interesting antioxidant activity (115 mg ascorbic acid equivalent/100 g) was found in optimized gluten-free bread.

3D-gradient coil structures for MRI designed using fuzzy membership functions

The design of high-performance gradient coils is essential for modern magnetic resonance imaging (MRI) applications. This work presents a new and alternative design methodology that explores three-dimensional (3D) solution space by combining fuzzy membership functions to model and re-shape the coil structure, given the magnetic field, electrical and mechanical constraints. The method was applied to design a short, unshielded asymmetric gradient coil for breast imaging. The resulting dome-shape coil has superior gradient performance compared to a standard fingerprint coil. New quadrupolar gradient coil designs for breast imaging are also obtained with the proposed method.

A magnetization mapping approach for passive shim design in MRI

A new passive shim design method is presented which is based on a magnetization mapping approach. Well defined regions with similar magnetization values define the optimal number of passive shims, their shape and position. The new design method is applied in a shimming process without prior-axial shim localization; this reduces the possibility of introducing new errors. The new shim design methodology reduces the number of iterations and the quantity of material required to shim a magnet. Only a few iterations (1-5) are required to shim a whole body horizontal bore magnet with a manufacturing error tolerance larger than 0.1 mm and smaller than 0.5 mm. One numerical example is presented.

Further evidence that the discriminative stimulus properties of indorenate are mediated by 5-HT 1A/1B/2C receptors

Indorenate (5-methoxytryptamine beta-methylcarboxylate, INDO) is a serotonin (5-hydroxytryptamine, 5-HT) agonist that has affinity for 5-HT(1A/1B/2C) receptors. Unlike other anxiolytics such as 5-HT receptor agonists, INDO may not share tolerance or dependency with the benzodiazepine anxiolytics. It has been reported that the discriminative stimulus properties of 5-HT(1A/1B/2C) agonists, but not those of 5-HT(3/4) agonists, generalize to INDO. Therefore, the aim of the present study was to obtain further evidence on the differential involvement of 5-HT(1A/1B/2C) receptors in the discriminative stimulus properties of INDO by evaluating its interactions with antagonists of the 5-HT(1A), 5-HT(1B), 5-HT(2C), and 5-HT(3/4) receptor subtypes. Rats were trained to discriminate INDO from saline in a conditioned taste aversion paradigm. For Group D(+)S(-), administration of INDO signalled that saccharin flavour was followed by LiCl, while injection of vehicle signalled safe consumption of saccharin solution. Group D(-)S(+) had the contingencies reversed. After this training, rats had generalization tests where INDO administration was preceded by different doses of the following antagonists: WAY100635 (5-HT(1A)), NAN190 (5-HT(1A)), methiothepin (5-HT(1A/1B/2C)), GR127935 (5-HT(1B/1D)), ketanserin (5-HT(2A/2C)), ritanserin (5-HT(2C/2A)), mesulergine (5-HT(2C/2A)), metergoline (5-HT(2C/2A)), SB206553 (5-HT(2B/2C)), and tropisetron (5-HT(3/4)). In Group D(+)S(-), the order of potency to block the discriminative stimulus properties of INDO was WAY100635>ketanserin>ritanserin>GR127935>mesulergine congruent with SB206553>metergoline>methiothepin>NAN190, while in Group D(-)S(+), the order was WAY100635>GR127935>ketanserin>ritanserin>mesulergine congruent with SB206553>metergoline>methiothepin>NAN190. Tropisetron did not produce any alteration of the discriminative control by INDO. These results suggest that the discriminative signal of INDO is mediated by 5-HT(1A/2C/1B) receptors and that blockade of any of its components produces a degradation of its discriminative effects.

[Prevalence of breast self-examination in health workers. Factors associated with its correct performance]

OBJECTIVE

Determine the frequency of a breast self-examination (BSE), in health workers and the associated risk factors in its correct performance.

MATERIAL AND METHODS

From January 24 to February 24, 2000, a transversal analytical study was performed in the workers of the General Hospital Zone number 32, of the IMSS in Minatitlán, Veracruz. 106 women were included, who verbally accepted to participate in the study. A self-administered survey was applied which contained variables of the use and performance of the BSE, social demographic variables, information about BSE, and positive health attitudes and faces with breast cancer.

RESULTS

A total of 92 (86.8%) of the workers have performed an BSE at least once in their life; 46.2% performed it adequately and 53.8% did not perform the technique adequately. The variables: profession, high social economical level, nulliparous after 25 years old, users of contraceptives, having visited a gynecologist for breast clinical examination, and if a family member recommended to perform a BSE, were related with the use adequately of BSE (p < 0.05).

CONCLUSIONS

The frequency of the use of a breast self-examination is high, however, it is not performed adequately by the majority of the women studied. Its correct execution is associated with the following variables: medical background doctor or nurse, well informed about BSE, family support and a positive health attitude. It is necessary to perform educational interventions so that the breast self-examination can be performed correctly.

Discriminative stimulus properties of indorenate, a 5-HT1A, 5-HT1B and 5-HT2C agonist: a study in rats

Indorenate (INDO), initially described as an antihypertensive agent, also has some effects on behaviour, with anxiolytic and anorectic actions being reported. The aim of the present experiment was to examine the activity of INDO at the behavioural level at various serotonin (5-hydroxytryptamine, 5-HT) receptor sites by comparing its stimulus properties with those of other 5-HT receptor agonists and by examining its interactions with some 5-HT antagonists. Rats were trained to discriminate between 10.0 mg/kg INDO (administered intraperitoneally (90 min before the start of the session) from saline. A Fixed Ratio 10 (FR10) schedule of reinforcement was in effect in each drug condition. During generalization test sessions, the discrimination index (DI, responses to drug lever/responses to drug + saline lever) was calculated from the responses emitted before the first reinforcer of the session. DI was a function of the dose of INDO employed. Generalization to the discriminative stimulus properties of INDO was observed with the 5-HT1A receptor agonist 8-OH-DPAT (1.0 mg/kg produced 90% generalization) and the 5-HT(1B/2C) receptor agonist 1-(3-trifluoromethylphenyl) piperazine (TFMPP) (3.0 mg/kg produced up to 75% generalization). Yohimbine (5.6 mg/kg), buspirone (1.0 mg/kg), 6-chloro-2-(1-piperaziny)pyrazine (1.0 mg/kg) and m-chlorophenylpiperazine (mCPP) (1.0 mg/kg) induced a DI of 70%, 50% and 48% and 55%, respectively. In generalization tests, ritanserin (0.01-1.0 mg/kg) induced saline-like responding. NAN-190 (3.0 mg/kg), a 5-HT1A receptor antagonist, was able to reduce the DI of INDO to 50%. Although the 5-HT(2C/2A) receptor antagonists cinanserin (10.0 mg/kg) and metergoline (0.3 mg/kg) were able to reduce the stimulus properties of INDO to 60% and 30%, respectively, only ritanserin (1.0 mg/kg) reduced the stimulus properties of INDO to 25% with a clear dose-response relationship. The results suggest that INDO acts as an agonist at 5-HT1A receptor sites, but its activity at 5-HT(1B/2C) receptor sites also contributes to its discriminative function.

Antisilicone antibodies in patients with silicone implants for retinal detachment surgery

A modified ELISA assay was used to detect IgG binding to silicone and IgG subtypes in serum of patients bearing silicone bands, silicone sponges and intraocular silicone oil. Presence of autoantibodies (rheumatoid factor, antinuclear antibody, and SCL 70) and signs and symptoms of autoimmune diseases were also checked. Antisilicone antibodies were detected in 35.7% of patients with solid silicone and in 83% in those with silicone oil. This increase in IgG is mainly due to IgG1. Nevertheless no positive results were found in detecting signs and symptoms of autoimmune diseases.

Lack of association between Helicobacter sp colonization and gallstone disease

Recently, Helicobacter sp has been identified in resected gallbladder tissue and in collected bile from Chilean patients with chronic cholecystitis. Therefore, it an association between bile Helicobacter sp and gallbladder cancer has been proposed. Interestingly, both Helicobacter colonization and gallstone disease (GD) happen very frequently in Chile. However, whether there is an association between Helicobacter colonization and GD has not been completely studied. The aim of this study was to determine the incidence of Helicobacter in human gallbladder tissues with GD. The study included 95 Mexican patients undergoing cholecystectomy. Collected gallbladder specimens were assessed to identify Helicobacter sp using histology, immunohistochemistry, and polymerase chain reaction (PCR) analysis using Helicobacter-specific 16-S ribosomal RNA primers. Of the 95 specimens examined in detail, all had stones as follows: 56 (59%) had chronic cholecystitis; 7 (7.4%), acute cholecystitis: 15 (16%), both chronic and acute cholecystitis, 10 (9.5%), cholesterolosis, and 7 (7.4%), lymphoid hyperplasia. Specimens were considered positive for Helicobacter when histology was positive. Only 1 of the 95 specimens was positive for Helicobacter by immunohistochemistry analysis; 1 of 32 cases, by PCR. These results suggest a low incidence of Helicobacter in the gallbladder epithelium of Mexican patients with GD. However, we can not discard the existence of uncommon Helicobacter sp in gallbladder epithelium and its association with gallstone pathogenesis. Additionally, this study suggests no apparent association between GD and Helicobacter colonization in a Mexican population.

Chromosome 11 abnormalities in myelodysplastic syndromes

Cytogenetic studies were performed in 140 patients with myelodysplastic syndrome (MDS) at diagnosis. Chromosome 11 anomalies were found in 7 cases (5%); 2 of these patients had refractory anemia (RA), 2 had refractory anemia with excess of blasts (RAEB), 1 had RAEB in transformation (RAEB-t), and 2 had chronic myelomonocytic leukemia (CMMoL) according to the French-American-British (FAB) Cooperative Group criteria. The chromosome 11 abnormalities comprised trisomy 11 (2 patients), monosomy 11 (1 patient), del(11)(q23) (2 patients), add(11)(p15) (1 patient), and der(11) t(3;11)(p21;q23) (1 patient). Abnormalities involving band q23 of chromosome 11 occurred in 3 cases and were the most common alteration. However, specific chromosomal alterations were not associated with any FAB classification group. These findings and their implications in the biology of MDS are discussed.

Discriminative stimulus properties of indorenate, a serotonin agonist

OBJECTIVE

To determine whether indorenate, a serotonin-receptor agonist, can exert discriminative control over operant responses, to establish the temporal course of discriminative control and to compare its stimulus properties to a (5-HT)IA receptor agonist. [3H]-8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT).

DESIGN

Prospective animal study.

ANIMALS

Ten male Wistar rats.

INTERVENTIONS

Rats were trained to press either of 2 levers for sucrose solution according to a fixed ratio schedule, which was gradually increased. Rats were given injections of either indorenate or saline solution during discrimination training. Once they had achieved an 83% accuracy rate, rats underwent generalization tests after having received a different dose of indorenate, the training dose of indorenate at various intervals before the test, various doses of 8-OH-DPT, or NAN-190 administered before indorenate or 8-OH-DPAT.

OUTCOME MEASURES

Distribution of responses between the 2 levers before the first reinforcer of the session, response rate for all the responses in the session, and a discrimination index that expressed the drug-appropriate responses as a proportion of the total responses.

RESULTS

Indorenate administration resulted in discriminative control over operant responses, maintained at fixed ratio 10, at a dose of 10.0 mg/kg (but not 3.0 mg/kg). When the interval between the administration of indorenate and the start of the session was varied, the time course of its cue properties followed that of its described effects on 5-HT turnover. In generalization tests, the discrimination index was a function of the dose of indorenate employed; moreover, administration of 8-OH-DPAT (from 0.1 to 1.0 mg/kg) fully mimicked the stimulus properties of indorenate in a dose-dependent way. The (5-HT)IA antagonist NAN-190 prevented the stimulus generalization from indorenate to 8-OH-DPAT. Also, NAN-190 antagonized the stimulus control of indorenate when administered 45 minutes before the session, but not when administered 105 minutes before the session (i.e., 15 minutes before the administration of indorenate).

CONCLUSION

(5-HT)IA receptors are of relevance to the stimulus function of indorenate. However, other receptor subtypes may also be involved. Hence, other agonists and specific antagonists should be studied before definite conclusions are drawn.

[Peripheral muscle strength in stable COPD patients: correlation with respiratory function variables and quality of life]

The aim of this study was to assess peripheral muscle strength in patients with chronic obstructive pulmonary disease (COPD) using a simple test and to look for correlation with function variables, physiological strength variables and quality of life parameters. Twenty-three COPD patients with moderate to severe air-flow limitation (FEV1 = 39 +/- 12%) in stable phase but displaying inability to carry out daily tasks were enrolled. Peripheral muscle strength was assessed in all patients by measuring the maximum load in a single repetition of five simple upper and lower extremity exercises performed at a multi-gymnastics station. Results were compared to respiratory function variables (FVC, FEV1, FEV1/FVC and gasometry), to results of an exercise test on a cycle ergometer with monitoring of respiratory gases (VEmax, VO2max and Wmax), to endurance (minutes) to dyspnea (Mahler's scale) and to quality of life (Chronic Respiratory Disease Questionnaire-CRDQ). No relation between functional parameters and endurance in minutes was found. Minute ventilation (VE) proved to be significantly related to oxygen intake (VO) and maximum work in the stress test. Dyspnea on Mahler's scale was unrelated, but fatigue variables and emotional function variables on the CRDQ were related. We conclude that peripheral muscle strength is unrelated to level of flow limitation or exercise tolerance in COPD patients. Peripheral muscle strength is related, however, to maximum work load and some aspects of quality of life.

[Efficacy of a program for tobacco use cessation with a combined substitution treatment of nicotine (patches plus chewing gum) at 6 months of follow-up]

Our aim was to assess the efficacy after 6 months of combined smoking cessation therapy using nicotine substitution with both chewing gum and patches. Sixty-six (25 women, 41 men) heavy smokers (38.04 packs/year and 8.42 mean score on Fagerström test) were followed between September 1995 and March 1997. Most patients were referred by respiratory, cardiology or ear-nose-and-throat outpatient clinics. The patients were prescribed 24-hour nicotine substitution therapy with 21 mg patches, plus chewing gum providing 2 mg of nicotine (3 to 10 per day) for a minimum of 8 weeks and a maximum of 12, with gradually decreasing doses. The patients were checked 1, 2, 4, 8, 12 and 24 weeks after enrollment. Expired air carbon monoxide was measured to confirm abstinence at each checkup and a simple questionnaire was filled in to assess abstinence syndrome and detect the presence of treatment side effects. Rate of abstinence achieved with this protocol after six months of follow-up was 37.9%. The failure rate was highest in the first week (33%) but gradually decreased until week 12. No patients had to abandon treatment due to side effects.

Assays for investigating RNA editing in plant mitochondria

In plant organelles transcripts are modified posttranscriptionally by RNA editing. This modification process changes almost every protein-coding RNA at specific cytidine and uridine positions. Therefore, mitochondrially encoded protein sequences differ from the genomically fixed information and show, after editing, a higher conservation. To investigate this unusual processing step in plant mitochondria, several assays have been developed. However, compared with the progress made in other RNA editing fields, knowledge about the factors involved in plant mitochondrial editing is limited. One reason for this is the lack of a reliable in vitro system for mitochondria. To reveal the biochemical nature of the RNA editing reaction in plant mitochondria, we developed an in vitro system by which we were able to show that cytidine is specifically modified to uridine by a deamination or transamination process. Here we describe the development of a pea in vitro system and discuss assays to follow the editing process.

Selective neuronal targeting in prion disease

The pattern of scrapie prion protein (PrP(Sc)) accumulation in the brain is different for each prion strain. We tested whether the PrP(Sc) deposition pattern is influenced by the Asn-linked oligosaccharides of PrP(C) in transgenic mice. Deletion of the first oligosaccharide altered PrP(C) trafficking and prevented infection with two prion strains. Deletion of the second did not alter PrP(C) trafficking, permitted infection with one prion strain, and had a profound effect on the PrP(Sc) deposition pattern. Our data raise the possibility that glycosylation can modify the conformation of PrP(C). Glycosylation could affect the affinity of PrP(C) for a particular conformer of PrP(Sc), thereby determining the rate of nascent PrP(Sc) formation and the specific patterns of PrP(Sc) deposition.

[Retrospective multicenter study of the efficacy of interferon alpha in chronic hepatitis C]

BACKGROUND

Until very recently, interferon (INF) in Spain was authorized in chronic hepatitis C (C-HCV) at a dosis of 3 megaunits (mu) for 6 months. Nonetheless, the rate of maintained complete response is lower than that obtained with more prolonged treatments. The first aim of this study was to retrospectively know the effectiveness of alpha INF in patients treated for 6 or 12 months with a dosis of 3 or 5-6 MU. The second was to analyze the characteristics of the patients who achieved a maintained complete response.

PATIENTS AND METHODS

Patients with C-HCV treated in 9 hospitals in Andalucía, Spain who fulfilled the following conditions were retrospectively analyzed: liver biopsy prior to treatment, positive test for anti HCV and a follow up of at least 6 months after alpha INF treatment. A total of 344 patients were studied: 267 treated with alpha INF-2b, 51 with alpha INF-2a and 26 with lymphoblastoid INF. One hundred ninety-five patients were treated for 6 months and 149 for 12 months.

RESULTS

Seventy-seven (22%) of the patients presented maintained complete response, 170 (50%) did not respond and 97 (28%) relapsed. On comparing the three types of interferon used over 6 months, no significant differences were observed. Neither were differences found on comparing the dosis of 3 mu versus 5 or 6 mu. On analyzing the treatments of 6 and 12 months, the following was observed, respectively: maintained complete response 15% vs 32%, relapse 29% vs 30% and non responders 57% vs 38% (p < 0.001). Multivariate analysis demonstrated that the patients who responded the best to INF were those who presented the following characteristics: female sex, age under 40 years last, history of transfusion or IVDA, basal GPT level higher than 145 IU/I, GGT less than 55 IU/I, less evolved histologic lesions and duration of treatment over 12 months.

CONCLUSIONS

Of the different treatments analyzed with alpha interferon in chronic hepatitis C, the best was found to be that with 3 mu during 12 months.

Transfer of rps19 to the nucleus involves the gain of an RNP-binding motif which may functionally replace RPS13 in Arabidopsis mitochondria

The discovery of disrupted rps19 genes in Arabidopsis mitochondria prompted speculation about the transfer to the nuclear compartment. We here describe the functional gene transfer of rps19 into the nucleus of Arabidopsis. Molecular cloning and sequence analysis of rps19 show that the nuclear gene encodes a long N-terminal extension. Import studies of the precursor protein indicate that only a small part of this extension is cleaved off during import. The larger part of the extension, which shows high similarity to conserved RNA-binding domains of the RNP-CS type, became part of the S19 protein. In the Escherichia coli ribosome S19 forms an RNA-binding complex as heterodimer with S13. By using immuno-analysis and import studies we show that a eubacterial-like S13 protein is absent from Arabidopsis mitochondria, and is not substituted by either a chloroplastic or a cytosolic homologue of this ribosomal protein. We therefore propose that either a highly diverged or missing RPS13 has been functionally replaced by an RNP domain that most likely derived from a glycine-rich RNA-binding protein. These results represent the first case of a functional replacement of a ribosomal protein by a common RNA-binding domain and offer a new view on the flexibility of biological systems in using well-adapted functional domains for different jobs.

Heart block in dextrocardia with situs inversus. A case report

The authors report a case of a forty-one-year-old white woman with dextrocardia with situs inversus who presented episodes of prolonged sinus arrest and syncopal episodes secondary to possible idiopathic degeneration of the conduction system, managed successfully with a permanent bicameral pacemaker. In their literature review they found that this case represents a very rare association.

[Thrombolysis in mechanical prosthetic valve thrombosis. Its management with streptokinase]

We present the first experience in Mexico in 10 patients, 9 female and 1 male with an average age of 42.5 years. All patients had clinical, echocardiographic and fluoroscopic criteria of dysfunctioning mechanical valvular prosthesis due to thrombosis (9 Sorin type and 1 Starr-Edwards). None of the patients had contraindications for thrombolytic therapy. All cases were treated with intravenous streptokinase: 250,000 U in 30 minutes followed by an infusion of 100,000 U per hour, always under clinical, echocardiographic and fluoroscopic control every 2 and 24 hours respectively until the normalization of the clinical and hemodynamic parameters with a top limit of 72 hour. The average duration of the thrombolysis was 54 +/- 6.1 hours with an average total doses of 5' 200,000 U of streptokinase. In 90% of the cases there was an increase in the valvular area: mitral (n = 7), from 1.02 +/- 0.21 to 1.75 +/- 0.36 cm2 (p < 0.001), while the mean transvalvular gradient decreased from 10.42 +/- 3.77 to 3.42 +/- 0.975 mmHg (p < 0.001); the systolic pulmonary artery pressure also decreased from 53.7 +/- 15.29 to 35 +/- 2 mmHg (p < 0.001). In the tricuspid prosthesis (n = 2) the average valvular area was increased from 0.8 +/- 0.44 to 1.55 +/- 0.77 cm2, decreasing proportionally the mean transvalvular gradient from 12.5 +/- 2 to 4.5 +/- 3.5 mmHg with no changes in the systolic pressure of the pulmonary artery. In the Starr-Edwards prosthesis in aortic position (n = 1), no hemodynamic changes were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Isolation of transcription promoters from Thiobacillus ferrooxidans and T. acidophilus and its introduction by conjugation to T. intermedius]

The chemolithotrophic acidophilic bacteria, Thiobacillus ferrooxidans is considered as the most important microorganism in relation to copper and uranium bioleaching ability. Since T. ferrooxidans is a strict chemolithotrophic microorganism, its genetic manipulation is a very hard task. Until now, all efforts have been unsuccessful. Therefore, we decided to approach the problem in steps, trying initially to manipulate some T. ferrooxidans related strains. We chose Thiobacillus acidophilus that shares its habitat with T. ferrooxidans and Thiobacillus intermedius, for its heterotrophic nature that makes them easier to grow and suitable for heterologous conjugation. The main objective of this work was directed towards the isolation and characterization of transcription promoters from T. acidophilus and T. ferrooxidans genomic DNA. Four different promoters from T. acidophilus and four from T. ferrooxidans were isolated and sequenced. In order to test their functional capacity in bacterial systems different from E. coli, they were subcloned and transferred to other bacteria. One of these recombinant plasmids was successfully transferred to T. intermedius and from it to Ps. putida. The subcloned promoter was able to confer streptomycin resistance to Ps. putida.

The yeast tRNA(Phe) gene family: structures and transcriptional activities reveal member differences not explained by intragenic promoters

Several cloned members of the yeast tRNA(Phe) gene family were transcribed in vitro using a HeLa extract and a yeast extract. The optimum DNA concentration was determined and kinetic experiments were performed for each clone to compare transcription levels. Both extract systems were able to splice the intervening sequence, but only the yeast extract produced the mature product. Some genes were not transcribed with the homologous system while they were transcribed with the HeLa extract, suggesting a control mechanism that is not operating in the heterologous system. Competition experiments demonstrated that the intragenic promoters of the inactive genes were able to bind transcription factor(s), but not as efficiently as active genes. This binding was not so strong when using linear DNA and was dependent on the presence of the 3' intragenic control region. DNA sequencing and computer analysis indicated the presence of short conserved sequences upstream from the genes. These sequences, which are not related to the intragenic promoters, are direct repeats of part of the 3' coding region in those genes that are transcribed in the homologous system. The relevance of these sequences on homologous transcription in vitro remains to be established.