Operational characteristics of ultrasound in the diagnosis of Sjögren's syndrome

BACKGROUND AND OBJECTIVE

To determine the operational characteristics of salivary gland ultrasound (SGU) in the diagnosis of Sjögren's syndrome (SS) in a population of colombian patients with dry symptoms.

MATERIALS AND METHODS

Study of diagnostic tests in patients with dry symptoms who consecutively attended the rheumatology consultation (2018-2020). Sociodemographic and clinical data were obtained through a survey, paraclinical and ophthalmological tests, minor salivary gland biopsy, unstimulated salivary flow and SGU (score 0-6 based on De Vita) were done. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values (Stata 15®) were calculated. The receiver operating characteristics (ROC) curve was developed.

RESULTS

102 patients were included (34 SS and 68 non-SS), mean age 55.69 (±11.93) years, 94% women. Positive ultrasound (score of 2 or more) was more frequent in the SS group, (70.6% vs. 22.1%, P<0.0001). The sensitivity was the same for grade 2 and 3 (70.59%), with a higher specificity (89.71%) for grade 3 (PPV 77.42% NPV 85.92). The ROC curve from the sum of the glands by means of ultrasound was better than those of the independent glands. The ROC curve of the ultrasound presented a greater area under the curve (0.72 [0.61-0.82]) than that of the histological analysis (focus score) (0.68 [0.59-0.78]), P=0.0252.

CONCLUSION

Salivary gland ultrasound is a useful and reliable method for the classification of SS. Its use could be considered in the future within the SS classification criteria.

Risk scores' performance and their impact on operative decision-making in left-sided endocarditis: a cohort study

The accuracy of contemporary risk scores in predicting perioperative mortality in infective endocarditis (IE) remains controversial. The aim is to evaluate the performance of existent mortality risk scores for cardiovascular surgery in IE and the impact on operability at high-risk thresholds. A single-center retrospective review of adult patients diagnosed with acute left-sided IE undergoing surgery from May 2014 to August 2019 (n = 142) was done. Individualized risk calculation was obtained according to the available mortality risk scores: EuroScore I and II, PALSUSE, Risk-E, Costa, De Feo-Cotrufo, AEPEI, STS-risk, STS-IE, APORTEI, and ICE-PCS scores. A cross-validation analysis was performed on the score with the best area under the curve (AUC). The 30-day survival was 96.5% (95%CI 91-98%). The score with worse area under the curve (AUC = 0.6) was the STS-IE score, while the higher was for the RISK-E score (AUC = 0.89). The AUC of the majority of risk scores suggested acceptable performance; however, statistically significant differences in expected versus observed mortalities were common. The cross-validation analysis showed that a large number of survivors (> 75%) would not have been operated if arbitrary high-risk threshold estimates had been used to deny surgery. The observed mortality in our cohort is significantly lower than is predicted by contemporary risk scores. Despite the reasonable numeric performance of the analyzed scores, their utility in judging the operability of a given patient remains questionable, as demonstrated in the cross-validation analysis. Future guidelines may advise that denial of surgery should only follow a highly experienced Endocarditis Team evaluation.

Neuroleptic malignant syndrome in a postoperative patient: A case report

Neuroleptic malignant syndrome is a rare medical emergency associated with the use of antipsychotics and other antidopaminergic drugs. There is no specific test, and diagnosis is based on high clinical suspicion and good differential diagnosis. A clinical picture consistent with hyperthermia, muscle rigidity, altered level of consciousness, together with signs of rhabdomyolysis in analytical studies and a history of taking neuroleptic drugs are the key elements in the detection of this entity. Due to its low incidence and potential mortality, it is essential to publish case reports of neuroleptic malignant syndrome in order to raise awareness of this entity and facilitate diagnostic suspicion when encountering a patient with compatible symptoms. The following is the case of a 79 year old patient with chronic alcohol consumption as the only history of interest, who was given a single dose of haloperidol after an episode of delirium in the postoperative period of conventional trauma surgery. She subsequently developed a picture of progressive deterioration of the level of consciousness, diaphoresis, generalized muscle rigidity, hyperthermia, together with severe metabolic acidosis, hyperlacticaemia, rhabdomyolysis, hypertransaminasemia and hypocalcemia. After ruling out other entities compatible with the clinical picture, neuroleptic malignant syndrome was given as the main diagnostic hypothesis. Diagnosis was confirmed after clinical and analytical improvement following treatment with dantrolene. The patient was discharged from hospital with no sequelae a few days after onset of the condition.

Neuroleptic malignant syndrome in a postoperative patient: a case report

Neuroleptic malignant syndrome is a rare medical emergency associated with the use of antipsychotics and other antidopaminergic drugs. There is no specific test, and diagnosis is based on high clinical suspicion and good differential diagnosis. A clinical picture consistent with hyperthermia, muscle rigidity, altered level of consciousness, together with signs of rhabdomyolysis in analytical studies and a history of taking neuroleptic drugs are the key elements in the detection of this entity. Due to its low incidence and potential mortality, it is essential to publish case reports of neuroleptic malignant syndrome in order to raise awareness of this entity and facilitate diagnostic suspicion when encountering a patient with compatible symptoms. The following is the case of a 79 year old patient with chronic alcohol consumption as the only history of interest, who was given a single dose of haloperidol after an episode of delirium in the postoperative period of conventional trauma surgery. She subsequently developed a picture of progressive deterioration of the level of consciousness, diaphoresis, generalized muscle rigidity, hyperthermia, together with severe metabolic acidosis, hyperlacticaemia, rhabdomyolysis, hypertransaminasemia and hypocalcemia. After ruling out other entities compatible with the clinical picture, neuroleptic malignant syndrome was given as the main diagnostic hypothesis. Diagnosis was confirmed after clinical and analytical improvement following treatment with dantrolene. The patient was discharged from hospital with no sequelae a few days after onset of the condition.

Non-invasive metabolomics for improved determination of embryonic sex markers in chemically defined culture medium

Metabolic differences between early male and female embryos can be reflected in culture medium (CM). We used a single bovine embryo culture step (24h) supporting improved birth rates under chemically defined conditions (CDC) to investigate biomarker detection of embryonic sex in contrast to classical BSA-containing medium. In vitro matured slaughterhouse oocytes were fertilized in vitro with a single bull. Embryos were initially cultured in synthetic oviduct fluid with BSA. On day-6, morulae were cultured individually in droplets with (BSA) or without protein (CDC). On day-7, expanded blastocysts were sexed (amelogenin gene amplification) and CM was stored at -145°C until metabolomic analysis by UHPLC-TOF MS. N=10 embryos per group (i.e. male-protein; female-protein; male-non-protein; female-non-protein) were produced. Statistical analysis revealed N=6 metabolites with different concentrations in CM, N=5 in male embryos (methionine, tryptophan, N-stearoyl-valine, biotin and pipecolic acid), N=1 in female embryos (threonine) (P<0.05 in BSA; P<10^-7 in CDC). Only the clear threshold between males and females in CDC allowed correct classification of 100% males and 91% females within 5 out of 6 biomarkers (one female outlier showing the male biomarker profile). The use of CDC represents a critical aspect in the efficient detection of embryonic sex biomarkers by metabolomics.

Effect of replacing dietary corn with beet pulp on energy partitioning, substrate oxidation and methane production in lactating dairy goats

The objective of this experiment was to study the effect of substitution of corn by beet pulp on energy partitioning, substrate oxidation, nitrogen and carbon balance and milk performance in dairy goats during late lactation. Twelve multiparous lactating Murciano-Granadina goats were fed two diets. Six goats were fed a mixed ration with 310 g/kg DM of ground corn (diet CORN) and in the other diet the corn was substituted with 302 g/kg DM of beet pulp (diet BP) in a cross-over design. No significant differences between diets were observed for milk production (1.36 kg/day, on average) and differences were found for milk fat (5.39 and 4.21% for BP and CORN, respectively). The metabolisable energy intake was higher (P < 0.05) in the CORN diet than BP (1320 vs 1044 kJ/kg0.75 BW, respectively). The difference in methane emissions between treatments was significant (P < 0.05) with values of 92 vs 61 kJ/kg0.75 BW for BP and CORN, respectively, indicating that greater levels of starch in diet reduce methane production. Replacing corn with BP reduced significantly the energy body fat deposition (300 vs 44 kJ/kg0.75 BW for CORN and BP diets, respectively). This reduction in energy retention for the BP diet did not compromise milk yield and milk energy output.

Paternal line multigenerational passage of altered risk assessment behavior in female but not male rat offspring of mothers fed a low protein diet

Maternal low protein (MLP) diets in pregnancy and lactation impair offspring brain development and modify offspring behavior. We hypothesized multigenerational passage of altered behavioral outcomes as has been demonstrated following other developmental programming challenges. We investigated potential multigenerational effects of MLP in rat pregnancy and/or lactation on offspring risk assessment behavior. Founder generation mothers (F0) ate 20% casein (C) or restricted (R) 10% casein diet, providing four groups: CC, RR, CR, and RC (first letter pregnancy, second letter lactation diet) to evaluate offspring (F1) effects influenced by MLP in F0. On postnatal day (PND 250), F1 males were mated to non-colony siblings producing F2. On PND 90, F2 females (in diestrous) and F2 males were tested in the elevated plus maze (EPM) and open field. Corticosterone was measured at PND 110. Female but not male CR and RC F2 made more entries and spent more time in EPM open arms than CC females. Overall activity was unchanged as observed in male F1 fathers. There were no open field differences in F2 of either sex, indicating that multigenerational MLP effects are due to altered risk assessment, not locomotion. MLP in pregnancy reduced F1 male and F2 female corticosterone. We conclude that MLP in pregnancy and/or lactation increases the innate tendency to explore novel environments in F2 females via the paternal linage, suggesting lower levels of caution and/or higher impulsiveness to explore unknown spaces. Further studies will be necessary to identify the epigenetic modifications in the germ line through the paternal linage.

Spatial and temporal dynamics of suspended load at-a-cross-section: the lowermost Ebro River (Catalonia, Spain)

Suspended load dynamics were analyzed for the period 2007-2009 in a semi-meandering cross-section under different hydrological conditions. Samples were collected at four different points of the cross-section. During "low discharges" (≤ 600 m³/s) suspended load samples were collected at-a-monthly basis, whereas at "high discharges" (> 600 m³/s) sampling was conducted intensively (at-a-daily basis during the first stages of the flood event). Results indicated that during low discharges, both organic and inorganic suspended load concentrations tended to be uniformly distributed across the fluvial section; but during high discharges, two distinct areas were found: an area extending from the "Inner-bank" to the "Channel centre" (Area-I) with higher suspended concentrations (organic and inorganic) than those recorded in the "Outer bank" (Area-II). This phenomenon was likely related to the formation of secondary flow velocity cells and the activation of new sources of sediment. In addition, a non-significant relationship between organic suspended load and water flow was observed in the outer-bank. At-a-monthly basis, the analysis of the suspended load showed the existence of an intra-annual cycle of the inorganic concentrations, with a progressive increase from October to March followed by a decrease from March to September. Nevertheless, the organic suspended load did not show any trend, being equally distributed along the year, suggesting that other sources of organic matter besides phytoplankton are predominant.

[Emergency anesthesia in a woman with mitochondrial neurogastrointestinal encephalopathy]

Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is characterized by leukoencephalopathy, peripheral neuropathy, ptosis, ophthalmoplegia, and gastrointestinal dysmotility. Mitochondrial myopathies are rare diseases and little is known of how to manage them when the patient requires anesthesia. We describe the anesthetic procedure used during emergency surgery for megacolon in a 26-year-old woman with MNGIE. Variables monitored were electrocardiogram, invasive arterial pressure, oxygen saturation by pulse oximetry, end-tidal carbon dioxide pressure, neuromuscular block, and depth of anesthesia (entropy). Rapid sequence induction was accomplished with midazolam, fentanyl, propofol, and rocuronium as an alternative to succinylcholine. Anesthesia was maintained with intravenous propofol; a second dose of the neuromuscular blocker was not required. No intraoperative problems developed and extubation was possible 2 hours after arrival in the postoperative critical care unit, once we had checked the level of block to confirm that reversion was not required.

The use of diatom assemblages as ecological indicators in highly stratified estuaries and evaluation of existing diatom indices

Diatom indices are used to evaluate the ecological status of rivers but they have been rarely applied in estuaries. This study aimed to identify the diatom species indicating the main environmental gradients and pressures in a highly stratified estuary; and to evaluate the applicability of existing freshwater diatom indices. Marine influence due to salt-wedge intrusion and sea water mixing appeared as the main factor affecting diatom community. Three diatom assemblages were identified: indicators of riverine conditions (without marine influence), indicators of estuarine conditions (heterogeneous conditions with higher conductivities due to marine influence) and those specifically indicating well-established salt-wedge situations. Nowadays, the main human pressure affecting diatom community in the Ebro Estuary is the hydrological alteration resulting from flow regulation and abstraction. Several limitations were encountered in the application of diatom indices (e.g. inverse response with nutrients; ecologically important species not considered). Therefore, their use in estuaries should be done cautiously.

Multilocus phylogeny and species delimitation within the Natterer's bat species complex in the Western Palearctic

Delimiting species is a crucial issue for many biological disciplines and is of primary importance for designing effective conservation plans. Traditional taxonomy based on morphological characters can be misled by the presence of phenotypic plesiomorphism or adaptative convergence. The use of multiple locus genetic data appears thus as a powerful tool for recognizing species boundaries. In this study, we used six nuclear introns and two mitochondrial markers to conduct a phylogenetic study of the Myotis nattereri species complex in the Western Palearctic. We combined tree-based and non-tree-based analyses, and also used concatenated phylogenetic methods of the separated nuclear and mitochondrial dataset as well as a recent coalescence-based multilocus approach. The strong concordance between the results of the analyses conducted confirms that M. nattereri is a paraphyletic group that is composed of four well-differentiated lineages in the study area. In the framework of the unified species concept, these four clades can be confidently considered as four valid species. This recognition of new cryptic species in the Western Mediterranean region shows that the biodiversity of this well-studied area is still not fully understood.

Asymptomatic rhabdovirus infection in meridional serotine bats (Eptesicus isabellinus) from Spain

Different rhabdoviruses have been found in healthy bats, suggesting asymptomatic infection. The aim of this study was to focus on the epidemiology and pathogenesis of EBLV1 infection in the meridional serotine bat (Eptesicus isabellinus), as well as to search for other rhabdoviruses in this bat, which is the responsible for more than 95% of cases of human exposure to lyssaviruses in Europe. RT-PCR on oropharyngeal swabs was used together with antibody detection by the Rapid Fluorescent Focus Inhibition Test (RFFIT) to investigate EBLV1 circulation in 19 natural colonies of meridional serotine bats in Andalusia (Spain) from 1998 to 2003. The survey was based on 1,227 different captures of 1,033 individuals that were ring banded, sampled and released. Individuals that were repeatedly captured were always found in the same colony, despite the fact that some colonies were less than five km apart. Viral circulation was detected in ten colonies either by RT-PCR, serology or both. Each colony showed a different temporal pattern of viral circulation suggesting independent endemic circulation. Some positive individuals were captured healthy in following campaigns providing evidence for survival after viral infection. RNA from two apparently new Dimarhabdoviruses was also found in the pharyngeal cavity of two healthy bats.

[Comparison of the double-lumen endotracheal tube and the Arndt bronchial blocker used by inexperienced anesthesiologists in right- and left-sided thoracic surgery]

OBJECTIVES

To compare the effectiveness, quality of lung collapse and time anesthesiology residents required for selective intubation using the double-lumen endotracheal tube (DLT) and the Arndt bronchial blocker (ABB).

PATIENTS AND METHODS

Patients were sequentially assigned to 2 groups according to the side of surgery and then to 2 additional subgroups according to the device used. For right-sided surgery an ABB was placed in the right main bronchus or a DLT was placed in the left bronchus; for left-sided surgery an ABB was inserted into the left bronchus or a DLT was placed on the right. DLTs were introduced into the glottis by direct laryngoscopy and then guided into the bronchus using a fiberoptic bronchoscope. ABBs were introduced according to the manufacturer's recommendations. All devices were placed in position by residents. The variables recorded were time to insert the device, number of malpositions, and quality of lung collapse.

RESULTS

Forty patients were included. Mean (SD) times for positioning each device were 4.12 (0.97) minutes for the ABB and 4.1 (2.7) minutes for the DLT in right-sided surgery and 7.92 (43) minutes for the ABB and 3.7 (1.8) minutes for the DLT in left-sided surgery (P < .015) for left sided surgery. There were no significant differences in the number of malpositionings. The quality of lung collapse was excellent in 90% of the cases.

CONCLUSIONS

In the hands of supervised, inexperienced anesthesiologists the ABB took longer to position for left-sided thoracic surgery.

Disruption of ephrin-A/EphA binding alters synaptogenesis and neural connectivity in the hippocampus

Ephrins are guidance cues that modulate axonal growth and the subsequent axonal topographic maps in many regions of the CNS. Here we studied the functional roles of ephrin-A/EphA interactions in the layer-specific pattern of axonal projections in the hippocampus by disrupting the ephrin-A signaling by over-expression of a soluble EphA receptor. Tracing experiments in EphA5-Fc over-expressing mice revealed that reduction of ephrin-A/EphA interactions did not affect the proper distribution of the main hippocampal afferents, i.e. entorhinal and commissural projections. However, further ultrastructural analyses showed a reduction in the density of synaptic terminals in the entorhinal and commissural termination layers in these mice. In addition, using anti-calbindin antibodies, we analyzed the dentate mossy fiber projections following disruption of ephrin-A/EphA interactions throughout developing hippocampus. While the main mossy fiber bundle appeared normal, the infrapyramidal bundle formed longer projections that established ectopic contacts in these transgenic mice. Later, the expected specific pruning of the infrapyramidal bundle was not observed at adult stages. Ultrastructural analyses confirmed a higher number of mossy fiber terminals in the infrapyramidal bundle in adult EphA5-Fc transgenic mice and showed that these terminals were larger and established a greater number of contacts than in controls. Our results demonstrate that ephrin-A/EphA interactions regulate the synaptogenesis of hippocampal afferents and the proper development and refinement of granule cell projections.

EBLV1 circulation in natural bat colonies of Eptesicus serotinus: a six year survey

The serotine bat (Eptesicus serotinus) accounts for 95 % of cases of human exposition to EBLV1. The aim of this study was to focus on the epidemiology and pathogenesis of EBLV1 infection in the serotine bat. Our first objective was the development of an RT-PCR technique for the specific detection of EBLV1 RNA in oro-pharyngeal swabs. This technique showed better performance than the classical immunofluorescence (IF) on brain in detecting EBLV1 in healthy flying bats. We have used this technique together with antibody detection by the fluorescent focus inhibition test (FFIT) to investigate EBLV1 circulation in 19 natural colonies of serotine bats in Andalusia (Spain) from 1998 to 2003. The survey was based on 1223 different captures of 1080 individuals that were ring banded, sampled and released. Individuals that were repeatedly captured were always found in the same colony even though some colonies were less than five Km apart. Viral circulation was detected in nine colonies either by RT-PCR, serology or both. Each colony showed a different temporal pattern of viral circulation suggesting independent endemic circulation. Some positive individuals were captured healthy in following campaigns evidencing survival after viral infection.

Mitochondrial phylogeography of the long-eared bats (Plecotus) in the Mediterranean Palaearctic and Atlantic Islands

Long-eared bats of the genus Plecotus are widespread and common over most of the western Palaearctic. Based on recent molecular evidence, they proved to represent a complex of several cryptic species, with three new species being described from Europe in 2002. Evolutionary relationships among the different lineages are still fragmentary because of the limited geographic coverage of previous studies. Here we analyze Plecotus mitochondrial DNA sequences from the entire Mediterranean region and Atlantic Islands. Phylogenetic reconstructions group these western Palaearctic Plecotus into two major clades which split at least 5 Myr ago and that are each subdivided into further subgroups. An 'auritus group' includes the traditional P. auritus species and its sister taxon P. macrobullaris (=P. alpinus) plus related specimens from the Middle East. P. auritus and P. macrobullaris have broadly overlapping distributions in Europe, although the latter is apparently more restricted to mountain ranges. The other major clade, the 'austriacus group,' includes the European species P. austriacus and at least two other related taxa from North Africa (including P. teneriffae from the Canary Islands), the Balkans and Anatolia (P. kolombatovici). The sister species of this 'austriacus group' is P. balensis, an Ethiopian endemic. Phylogenetic reconstructions further suggest that P. austriacus reached Madeira during its relatively recent westward expansion through Europe, while the Canary Islands were colonized by a North African ancestor. Although colonization of the two groups of Atlantic Islands by Plecotus bats followed very distinct routes, neither involved lineages from the 'auritus group.' Furthermore, the Strait of Gibraltar perfectly segregates the distinct lineages, which confirms its key role as a geographic barrier. This study also stresses the biogeographical importance of the Mediterranean region, and particularly of North Africa, in understanding the evolution of the western Palaearctic biotas.

Intravenous immunoglobulin preparations and autoimmune disorders: mechanisms of action

Intravenous immunoglobulins (IVIg) have been used as a substitutive treatment for primary and secondary humoral immune deficiencies for several decades. In the meantime, increased experience has been acquired with IVIg in the management of other inflammatory and autoimmune disorders, such as Kawasaki's disease, idiopathic thrombocytopenic purpura, dermatomyositis or Guillain-Barré syndrome, in which several clinical trials have demonstrated its efficacy. In other pathologies, IVIg seem to be effective, although further studies are required. Nevertheless, the exact mechanism by which IVIg exert their beneficial actions is not completely understood. According to in vitro as well as in vivo data, several mechanisms of action have been proposed: Fc receptor blockade, idiotype-anti-idiotype interactions, neutralisation of bacterial toxins and superantigens, competitive inhibition of complement activation, down-regulation of B- and T-cell function, enhancement of pathogenic autoantibodies clearance, modulation of soluble products, apoptosis blockade via Fas receptor and administration of soluble products which could interfere with the immune response. Both IVIg structure, as well as its obtention from pooled human plasma donors, seem to play an important role in IVIg immunomodulatory properties. Thus, the objective of the present article is to review the current evidence upon the mechanisms of action of IVIg.

[Prevalence of psychiatric disorders in men and women hospitalized in a internal medicine service of a hospital of Santiago, Chile]

BACKGROUND

Mental disorders may interfere, aggravate or mimic medical conditions.

AIM

To study the prevalence of psychiatric disorders among patients hospitalized in a medical ward of a general hospital.

PATIENTS AND METHODS

A structured interview for DSM-III, devised for "non patients", was applied to 203 men and 203 women, aged 11 to 90 years old, hospitalized in an internal medicine service of a public hospital. Thirty four psychiatric conditions that can be discriminated with the instrument and others that complied with DSM-III criteria, were investigated.

RESULTS

There was a 60% prevalence of mental disorders among men (alcohol dependency in 26%, delirium or dementia in 10.8%, anxiety disorders in 10.4%, major depression in 7.8% and adaptation disorders in 3%). Among women, the prevalence of mental disorders was 65% (major depression in 23.2%, anxiety disorders in 14.3%, adaptation disorders in 8.4%, dementia in 5.6%, delirium in 3% and alcohol dependency in 2.5%). Most conditions were of moderate or mild intensity. Two or more conditions coexisted in 40% of cases. Only in 8% of these subjects, a psychiatric consultation was requested.

CONCLUSIONS

There is a high frequency of psychiatric disorders among medical patients. These must be adequately diagnosed and treated.

Screening of active lyssavirus infection in wild bat populations by viral RNA detection on oropharyngeal swabs

Brain analysis cannot be used for the investigation of active lyssavirus infection in healthy bats because most bat species are protected by conservation directives. Consequently, serology remains the only tool for performing virological studies on natural bat populations; however, the presence of antibodies merely reflects past exposure to the virus and is not a valid marker of active infection. This work describes a new nested reverse transcription (RT)-PCR technique specifically designed for the detection of the European bat virus 1 on oropharyngeal swabs obtained from bats but also able to amplify RNA from the remaining rabies-related lyssaviruses in brain samples. The technique was successfully used for surveillance of a serotine bat (Eptesicus serotinus) colony involved in a case of human exposure, in which 15 out of 71 oropharyngeal swabs were positive. Lyssavirus infection was detected on 13 oropharyngeal swabs but in only 5 brains out of the 34 animals from which simultaneous brain and oropharyngeal samples had been taken. The lyssavirus involved could be rapidly identified by automatic sequencing of the RT-PCR products obtained from 14 brains and three bat oropharyngeal swabs. In conclusion, RT-PCR using oropharyngeal swabs will permit screening of wild bat populations for active lyssavirus infection, for research or epidemiological purposes, in line not only with conservation policies but also in a more efficient manner than classical detection techniques used on the brain.

Bat predation on nocturnally migrating birds

Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

Isosporosis and unizoite tissue cysts in patients with acquired immunodeficiency syndrome

Isospora belli, a coccidian parasite in humans, has been described as causing chronic diarrhea and acalculous cholecystitis in patients with the acquired immunodeficiency syndrome (AIDS). Diagnosis can be made at the tissue level in the epithelium of the small bowel and by fecal examination. Disseminated extraintestinal forms are uncommon. We studied 118 adult patients with AIDS and chronic diarrhea using stool analysis and endoscopy with duodenal biopsy specimen collection. These samples were processed by routine histology and transmission electron microscopy. Isosporosis was diagnosed in 8 cases. In 2 of them, unizoite tissue cysts were present in the lamina propria, with negative results in stool materials. The cysts were located within a large parasitophorous vacuole. There were no structural means of differentiating the species level of Isospora based on morphology using light or electron microscopy. We believe further work should be done to determine if unizoite tissue cysts are part of the cycle of I belli or of other species of Isospora that could be pathogenic in immunocompromised hosts.

Is the Gibraltar strait a barrier to gene flow for the bat Myotis myotis (Chiroptera: Vespertilionidae)?

Because of their role in limiting gene flow, geographical barriers like mountains or seas often coincide with intraspecific genetic discontinuities. Although the Strait of Gibraltar represents such a potential barrier for both plants and animals, few studies have been conducted on its impact on gene flow. Here we test this effect on a bat species (Myotis myotis) which is apparently distributed on both sides of the strait. Six colonies of 20 Myotis myotis each were sampled in southern Spain and northern Morocco along a linear transect of 1350 km. Results based on six nuclear microsatellite loci reveal no significant population structure within regions, but a complete isolation between bats sampled on each side of the strait. Variability at 600 bp of a mitochondrial gene (cytochrome b) confirms the existence of two genetically distinct and perfectly segregating clades, which diverged several million years ago. Despite the narrowness of the Gibraltar Strait (14 km), these molecular data suggest that neither males, nor females from either region have ever reproduced on the opposite side of the strait. Comparisons of molecular divergence with bats from a closely related species (M. blythii) suggest that the North African clade is possibly a distinct taxon warranting full species rank. We provisionally refer to it as Myotis cf punicus Felten 1977, but a definitive systematic understanding of the whole Mouse-eared bat species complex awaits further genetic sampling, especially in the Eastern Mediterranean areas.

Digoxin level and clinical manifestations as determinants in the diagnosis of digoxin toxicity

The aim of this study was to determine the relative importance of different risk factors in the diagnosis of digitalis toxicity. The authors recruited inpatients for whom serum digoxin level was requested and prospectively followed them for a week to ascertain if they showed digitalis toxicity. The predictive value of different factors for the assessment of digoxin toxicity was analyzed by multiple logistic regression. Forty-one toxic and 58 nontoxic patients were included. In the univariant analysis, intoxicated patients were older, most were women, and they had worse renal function and higher digoxin level; but there were no differences in serum electrolytes or other risk factors. In the multivariant analysis, digoxin level was the only independent factor related to digitalis toxicity. A different risk of toxicity for each clinical manifestation was found for a certain digoxin level. Patients with signs of automaticity in the electrocardiogram had a higher likelihood of being intoxicated than patients with gastrointestinal symptoms, atrioventricular block, or bradycardia. Therefore, in the population evaluated in this study, digoxin level is the key independent factor in digoxin intoxication, although the probability of being intoxicated is also a function of the type of clinical manifestations. A graphic approximation of this probability based on these two factors is presented.

Phylogeography of African fruitbats (Megachiroptera)

Joint sequences from the mitochondrial cytochrome b and 16S rRNA genes of a wide representation of Megachiroptera were employed to evaluate the traditional taxonomic arrangement of African fruitbats and to examine their origins and evolutionary relationships. The resulting phylogenetic hypotheses are inconsistent with the previously established morphology-based subdivisions of Megachiroptera at the suprageneric level. Findings indicate the existence of an African clade, which appears to be formed by two endemic clades: the epomophorines and the myonycterines. According to our topologies, the genus Rousettus is monospecific in mainland Africa. Its traditional subgenera Stenonycteris and Lissonycteris appear closer to the myonycterines than to Rousettus. Topologies also indicate that the African genus Eidolon is not phylogenetically related to any other African fruitbat. It would seem that the arrival of fruitbats in Africa was a complex process involving at least three independent colonization events. One event took place probably in the Miocene via forested corridors that connected the African and Asian rain forest blocks, as for other groups of mammals. The resulting lineage diversified into most of the extant African fruitbats. Related to this clade, the Rousettus species group is thought to have arrived in Africa in more recent times, possibly by progressive displacement from the East through India. Finally, the present topologies suggest an independent colonization of Africa by ancestors of Eidolon.

Molecular phylogeny and morphological homoplasy in fruitbats

The present study evaluates the evolutionary framework of the Old World fruitbats based on the cytochrome b and 16S rRNA mitochondrial gene sequences from a wide range of taxa. Phylogenetic analyses indicated that morphology-based subfamilies and most suprageneric groups are nonnatural assemblages. They also support the existence of an endemic African clade of fruitbats. The discrepancy between the evolutionary relationships yielded by molecular and morphological data sets may be, at least in part, explained by the recurrent retention of primitive morphology (Rousettus-like) across different lineages. The maintenance of primitive characters in different groups of flying foxes, as well as morphological convergence in nectar-feeding bats and possibly also in short-muzzle bats, may have led to high levels of homoplasy, resulting in misleading taxonomic arrangements. This may be particularly so with respect to high taxonomic levels based on morphological characters.

An ethanol-inducible MDR ethanol dehydrogenase/acetaldehyde reductase in Escherichia coli: structural and enzymatic relationships to the eukaryotic protein forms

An ethanol-active medium-chain dehydrogenase/reductase (MDR) alcohol dehydrogenase was isolated and characterized from Escherichia coli. It is distinct from the fermentative alcohol dehydrogenase and the class III MDR alcohol dehydrogenase, both already known in E. coli. Instead, it is reminiscent of the MDR liver enzyme forms found in vertebrates and has a K(m) for ethanol of 0.7 mM, similar to that of the class I enzyme in humans, however, it has a very high k(cat), 4050 min(-1). It is also inhibited by pyrazole (K(i) = 0.2 microM) and 4-methylpyrazole (K(i)= 44 microM), but in a ratio that is the inverse of the inhibition of the human enzyme. The enzyme is even more efficient in the reverse direction of acetaldehyde reduction (K(m) = 30 microM and k(cat) = 9800 min(-1)), suggesting a physiological function like that seen for the fermentative non-MDR alcohol dehydrogenase. Growth parameters in complex media with and without ethanol show no difference. The structure corresponds to one of 12 new alcohol dehydrogenase homologs present as ORFs in the E. coli genome. Together with the previously known E. coli MDR forms (class III alcohol dehydrogenase, threonine dehydrogenase, zeta-crystallin, galactitol-1-phosphate dehydrogenase, sensor protein rspB) there is now known to be a minimum of 17 MDR enzymes coded for by the E. coli genome. The presence of this bacterial MDR ethanol dehydrogenase, with a structure compatible with an origin separate from that of yeast, plant and animal ethanol-active MDR forms, supports the view of repeated duplicatory origins of alcohol dehydrogenases and of functional convergence to ethanol/acetaldehyde activity. Furthermore, this enzyme is ethanol inducible in at least one E. coli strain, K12 TG1, with apparently maximal induction at an enthanol concentration of approximately 17 mM. Although present in several strains under different conditions, inducibility may constitute an explanation for the fairly late characterization of this E. coli gene product.

[Estimation of the use of seat belts: an observational study and a telephone survey]

OBJECTIVE

To estimate the prevalence of safety-belt use in a telephone survey and an observational survey.

PATIENTS AND METHODS

Observational survey. Trained interviewers studied 4,067 front-seat occupants, at ten intersections of Madrid, according to "National Highway Traffic Safety Administration" guidelines. TELEPHONE SURVEY: We selected 433 front seat occupants from the Madrid city residential telephone directory. The questionnaire was completed by trained interviewers.

RESULTS

Prevalence by the observational survey was 58.5%, and was significantly higher at interurban intersections (OR = 2.1) than city intersections. In the telephone survey, the overall prevalence was 94% at interurban area and 64% at city area and it was associated with no history of lines and positive opinion of effectiveness of safety belts.

CONCLUSIONS

The safety belt prevalence observed is low, especially in the urban area. The telephone survey overestimates the safety belt use, but contributes with useful information for planning strategies.

[Clinical, epidemiologic, and microbiologic study of urinary infection in patients with renal transplant at a specialized center in Argentina]

Sixty-four patients were evaluated for urinary tract infection (UTI) during the first six months after renal transplantation. Eighty per cent received the allograft from a living, related donor and 37% were female. The median age was 33.8 years. All the patients received cefazolin as perioperative antibiotic prophylaxis. No prophylaxis was given during the bladder catheterization period, which had a median duration of 5.9 days. Nineteen per cent developed predisposing urological factors (PUF). The incidence of UTI was 41% and 15% of all these patients developed bacteremia from this source. UTI was observed in 50% of the patients without PUF between the 5th and 12th days post-transplantation, and these cases had been detected by the control urine culture performed when the bladder catheter was withdrawn. This group of patients accounted for 14% of all the patients. Recurrence was present in 42% of the patients with UTI (19% had reinfection, 4% relapse and 19% both). They were more frequent in patients with PUF than in the patients without; 78% vs. 24%, respectively (p < 0.05). The overall UTI incidence was also higher; 75% vs. 33%, respectively (p < 0.05). The same was observed for the median number of episodes (3 vs. 1). The organisms most frequently isolated were E. faecalis (21%). E. cloacae (17%), and E. coli (17%). Species prevalence differs from that of other reports, probably due to the different institutional antibiotic management. Since half of the UTI episodes suffered by patients without PUF were associated to bladder catheterization, there is a need to institute antibiotic prophylaxis in our center.

[Bilateral Leydig cell tumor]

A 7 year old boy presented with bilateral nodular testicular swelling, adult penis development and scrotal aspect. Laboratory studies revealed a bone age of 13 years, increased testosterone, estradiol, DHEA-S, and 17 ketosteroids levels. The GnRH test revealed puberal findings. Biopsy was consistent with Leydig cell tumor with presence of Reinke crystals. After enucleation of the tumor signs of necrosis and malignancy were shown. Orchiectomy will follow as chemotherapy and radiotherapy have been reported to be without value.

Overproduction and purification of the connector protein of Bacillus subtilis phage phi 29

A phi 29 DNA fragment containing genes 10 and 11, coding for the connector protein and the lower collar protein, respectively, has been cloned in the pBR322 derivative plasmid pKC30 under the control of the PL promoter of phage lambda. Two polypeptides with the electrophoretic mobility of proteins p10 and p11 were labelled with 35S-methionine after heat induction. The proteins were characterized as p10 and p11 by radioimmunoassay and they represented about 10% and 7%, respectively, of the total E. coli protein after 4 hours of induction. These proteins represent less than 1% of the B. subtilis protein in phi 29-infected cells. Protein p10 has been highly purified from the E. coli cells carrying the recombinant plasmid. Antibodies raised against the purified protein p10 reacted with the connector protein produced in phi 29-infected B. subtilis.