Structure of a microbial homologue of mammalian platelet-activating factor acetylhydrolases: Streptomyces exfoliatus lipase at 1.9 A resolution

BACKGROUND

Neutral lipases are ubiquitous and diverse enzymes. The molecular architecture of the structurally characterized lipases is similar, often despite a lack of detectable homology at the sequence level. Some of the microbial lipases are evolutionarily related to physiologically important mammalian enzymes. For example, limited sequence similarities were recently noted for the Streptomyces exfoliatus lipase (SeL) and two mammalian platelet-activating factor acetylhydrolases (PAF-AHs). The determination of the crystal structure of SeL allowed us to explore the structure-function relationships in this novel family of homologous hydrolases.

RESULTS

The crystal structure of SeL was determined by multiple isomorphous replacement and refined using data to 1.9 A resolution. The molecule exhibits the canonical tertiary fold of an alpha/beta hydrolase. The putative nucleophilic residue, Ser131, is located within a nucleophilic elbow and is hydrogen bonded to His209, which in turn interacts with Asp177. These three residues create a triad that closely resembles the catalytic triads found in the active sites of other neutral lipases. The mainchain amides of Met132 and Phe63 are perfectly positioned to create an oxyanion hole. Unexpectedly, there are no secondary structure elements that could render the active site inaccessible to solvent, like the lids that are commonly found in neutral lipases.

CONCLUSIONS

The crystal structure of SeL reinforces the notion that it is a homologue of the mammalian PAF-AHs. We have used the catalytic triad in SeL to model the active site of the PAF-AHs. Our model is consistent with the site-directed mutagenesis studies of plasma PAF-AH, which implicate Ser273, His351 and Asp296 in the active site. Our study therefore provides direct support for the hypothesis that the plasma and isoform II PAF-AHs are triad-containing alpha/beta hydrolases.

[Comparative study of the frequency and features of emotional disturbances in patients in primary care clinics]

BACKGROUND

Psychological problems are a frequent cause of consultation in primary care outpatient clinics.

AIM

To report the results for Santiago de Chile of the World Health Organisation multicentric collaborative study on Psychological Symptoms in General Health Care.

PATIENTS AND METHODS

The results of 1453 patients that attended three primary care clinics in East Metropolitan Santiago were compared with those of patients studied in 15 other centers throughout the world. Two hundred fifty three cases were studied in detail with a structured diagnostic interview (CIDI-PHC). The capacity of general physicians to recognise emotional disorders as well as their management of psychological cases was also assessed.

RESULTS

Among the 253 patients studied in detail, 53% of patients had a definite psychiatric diagnosis, compared with 24% of patients, as an average, in other countries. There was a higher prevalence of depression, generalised anxiety disorder, neurasthenia and harmful use of alcohol. Chilean physicians recognised 74.1% of patients with psychiatric conditions, as compared with 48.9% of physicians abroad. Tranquilizing agents were the most often prescribed medications (40%) followed by antidepressants (18%).

CONCLUSIONS

There is a high prevalence of emotional disorders in patients consulting at the primary care level.

The flanking region sequences of the 15-kDa lipoprotein gene differentiate pathogenic treponemes

The species Treponema pallidum includes three subspecies (pallidum, pertenue, and endemicum) that cause syphilis, yaws, and bejel, respectively. A closely related species, Treponema paraluiscuniculi, is the etiologic agent of venereal syphilis in rabbits but does not infect humans. Although these treponemes cause distinct diseases, no laboratory method for differentiation has been reported. Genetic signatures were defined in the 5' and 3' flanking regions of the 15-kDa lipoprotein gene (tpp15) that distinguish the human pathogens and T. paraluiscuniculi, as well as distinguishing T. pallidum subsp. pallidum from the causes of human nonvenereal treponematoses. A single Eco47III restriction site in the 5' flanking region differentiates T. pallidum subsp. pallidum from the other subspecies and species, and an XcmI site in the 3' flanking region differentiates T. paraluiscuniculi from the human pathogens. Polymerase chain reaction methods and restriction polymorphism were used to analyze 27 strains of pathogenic Treponema species.

Assembly of chimeric connexin-aequorin proteins into functional gap junction channels. Reporting intracellular and plasma membrane calcium environments

Chimeric proteins comprising connexins 26, 32, and 43 and aequorin, a chemiluminescent calcium indicator, were made by fusing the amino terminus of aequorin to the carboxyl terminus of connexins. The retention of function by the chimeric partners was investigated. Connexin 32-aequorin and connexin 43-aequorin retained chemiluminescent activity whereas that of connexin 26-aequorin was negligible. Immunofluorescent staining of COS-7 cells expressing the chimerae showed they were targeted to the plasma membrane. Gap junction intercellular channel formation by the chimerae alone and in combination with wild-type connexins was investigated. Stable HeLa cells expressing connexin 43-aequorin were functional, as demonstrated by Lucifer yellow transfer. Paris of Xenopus oocytes expressing connexin 43-aequorin were electrophysiologically coupled, but those expressing chimeric connexin 26 or 32 showed no detectable levels of coupling. The formation of heteromeric channels constructed of chimeric connexin 32 or connexin 43 and the respective wild-type connexins was inferred from the novel voltage gating properties of the junctional conductance. The results show that the preservation of function by each partner of the chimeric protein is dictated mainly by the nature of the connexin, especially the length of the cytoplasmic carboxyl-terminal domain. The aequorin partner of the connexin 43 chimera reported calcium levels in COS-7 cells in at least two different calcium environments.

Proliferative effect of insulin on cultured smooth muscle cells from rat mesenteric resistance vessels

The present study evaluates the growth promoting effect of insulin on the proliferative activity of cells from rat mesenteric arteries in culture in order to test the hypothesis that insulin may play a pathogenetic role in the hypertrophy of resistance vessels. The proliferative effect of insulin was studied in cultured vascular smooth muscle cells (SMC) obtained from two functionally different rat vessels: mesenteric arteries and aorta. Growth characteristics (cell number and growth rate) of mesenteric and aortic cells were determined after a quiescent period and followed-up for 24, 72, and 120 h after the addition of insulin. At all studied time intervals, aortic SMC exhibited a significatively higher cell number and specific growth rate than did mesenteric SMC. Aortic SMC also displayed a greater proliferation than did mesenteric SMC in the presence of 10% fetal calf serum (FCS). At a physiological concentration of 100 microU/mL, the proliferative effect of insulin, after a quiescent period, was seen only in aortic SMC, at 72 and 120 h. Higher insulin concentration (500 microU/mL) increased significantly the cell number in SMC of both arteries. The proliferative effect was significant at all studied periods for aortic SMC; however, in mesenteric SMC, insulin increased the cell number only at 72 and 120 h. The proliferative effect of insulin was observed on SMC obtained from functionally different arteries such as aorta and mesenteric, being greater in the former. The different behavior of these SMC in the presence not only of insulin, but also of 10% FCS, provides further evidence for the existence of intervascular heterogeneity. The mild stimulatory effect of insulin in vitro may contribute in this way to the vascular hypertrophy of pathological entities exhibiting hyperinsulinemia.

Evidence for a low temperature transition state binding preference in bovine adenosine deaminase

Arrhenius plots of the interactions of bovine adenosine deaminase (ADA) and of coformycin-inhibited ADA with adenosine are non-linear and reveal that coformycin significantly increases the activation energy for reaction only at temperatures well below the normal operating temperature of the enzyme (38.3 degrees C). This apparent enhanced affinity of the enzyme for the transition state analog at low temperature is confirmed from determinations of coformycin binding at 38.3 degrees C (KI = 5.3 x 10(-11) M) and at 21 degrees C (KI = 1.1 x 10(-11) M). It is suggested that these data are inconsistent with a model for general enzyme catalysis that requires an initial transition state complementary active site. Instead, it is suggested that an initial active site transition state complementarity is undesirable and the tendency of the enzyme to exist in this conformer at low temperatures is responsible for its inefficient interaction with adenosine substrate.

[Accumulation of actin and adhesion to HEp-2 cells of strains of Escherichia coli isolated from children with diarrhea in Mendoza, Argentina]

E. coli strains are the major bacterial cause of diarrhea among children under 2 years of age residing in Mendoza, Argentina. Detection of diarrheogenic E. coli is made after coproculture, by agglutination tests using O-group antisera including most enteropathogenic E. coli (EPEC) serogroups and others often isolated in diarrhea. Although there are many O serogroups and H serotypes of E. coli strongly associated with infantile diarrhea, a number of studies have shown differences in the rate of isolation of EPEC between cases and controls using DNA probes. We compared the diagnosis of EPEC infections by traditional serogrouping tests with other detection methods using cell culture, involving the screening of isolates for adherence patterns to HEp-2 cells. A total of 140 isolates from children less than 24 months old with acute, persistent and chronic diarrhea and 40 isolates from controls were recovered. Three distinct patterns of adherence, termed localised (LA), diffuse (DA) and aggregative (EAgg) adherence were found. The fluorescence actin staining assay was used as indicative of the ability of some EPEC strains that produce attaching-effacing (A/E) lesions. Positive serogrouping strains were strongly associated with adherence (P = 0.0001). LA adherence pattern occurred in 11% of cases with acute diarrhea associated with these serogroups (P = 0.001) and children under 12 months (P = 0.0001). The FAS test was positive in 80% of them. EAgg adherence was found only in patients (20% P = 0.0001) and DA occurred both in cases (29%) and controls (2.5% P = 0.0001). Diagnosis of EPEC infections has traditionally been performed by identifying organisms belonging to a number of serogroups or serotypes epidemiologically linked to diarrhea. Evidence is presented in this paper to show that pathogenicity is not restricted to serogroups. Isolation of many adherent strains not belonging to traditional EPEC O serogroups, shows the need for alternative methods to be used to detect and identify E. coli.

bldA-dependent expression of the Streptomyces exfoliatus M11 lipase gene (lipA) is mediated by the product of a contiguous gene, lipR, encoding a putative transcriptional activator

Extracellular lipase synthesis by Streptomyces lividans 66 carrying the cloned lipase gene (lipA) from Streptomyces exfoliatus M11 was found to be growth phase dependent, since lipase was secreted into the medium mainly during the stationary phase; S1 nuclease protection experiments revealed abundant lipA transcripts in RNA preparations obtained during the stationary phase but not in those obtained during exponential growth. Transcription from the lipA promoter was dependent on the presence of lipR, a contiguous downstream gene with a very high guanine-plus-cytosine content (80.2%). The deduced lipR product consists of a protein of 934 amino acids that shows similarity to known transcriptional activators and has a strong helix-turn-helix motif at its C terminus; this motif is part of a domain homologous to DNA-binding domains of bacterial regulators of the UhpA/LuxR superfamily. The lipR sequence revealed the presence of a leucine residue, encoded by the rare TTA codon, which caused bldA dependence of lipA transcription in Streptomyces coelicolor A3(2); replacement of the TTA codon by the alternate CTC leucine codon alleviated bidA dependence but not the apparent growth phase-dependent regulation of lipA transcription. When lipR expression was induced in a controlled fashion during the exponential growth phase, by placing it under the inducible tipA promoter, lipase synthesis was shifted to the exponential growth phase, indicating that the timing of lipR expression, and not its bldA dependence, is the main cause for stationary-phase transcription of lipA.

The value of hysteroscopic exploration for abnormal uterine bleeding

STUDY OBJECTIVE

To determine sensitivity, specificity, positive predictive value, negative predictive value, and global diagnostic precision of hysteroscopic exploration in the diagnosis of endometrial hyperplasia and adenocarcinoma in women with abnormal uterine bleeding.

DESIGN

Retrospective analysis.

SETTING

University-affiliated hospital.

PATIENTS

One thousand three hundred ninety-eight patients with abnormal uterine bleeding, 57.3% premenopausal and 42.6% postmenopausal.

INTERVENTIONS

Diagnostic hysteroscopy and subsequent dilatation and curettage.

MEASUREMENTS AND MAIN RESULTS

Endometrium was classified hysteroscopically as normal, atrophic, endometrial hyperplasia, and endometrial carcinoma. Histopathologic diagnosis was performed to determine the efficacy of hysteroscopy in diagnosing endometrial hyperplasia and adenocarcinoma. For endometrial hyperplasia in premenopausal women, sensitivity was 71.8%, specificity 96.4%, and global diagnostic precision 92.5%; in postmenopausal women, respective figures were 85. 1%, 100%, and 97.3%. For diagnosing adenocarcinoma in premenopausal patients, hysteroscopy was 100% sensitive, with specificity 99.4% and global diagnostic precision 99.5%; in postmenopausal women, respective figures were 100%, 99.4%, and 99.5%.

CONCLUSIONS

In women with abnormal uterine bleeding, diagnostic hysteroscopy is a basic tool that allows precise diagnosis of endouterine lesions such as polyps and submucous myomas. It also is highly accurate for evaluating endometrial adenocarcinoma and hyperplasia.

Species-specific voltage-gating properties of connexin-45 junctions expressed in Xenopus oocytes

Gap junctions composed of connexin-45 (Cx45) homologs from four species, zebrafish, chicken, mouse, and human, were expressed in pairs of Xenopus oocytes. The macroscopic conductance (gj) of all Cx45 junctions was modulated by transjunctional voltage (Vj) and by the inside-outside voltage (Vm), and the modulation was species specific. Although their gating characteristics varied in voltage sensitivity and kinetics, the four Cx45 junctions shared 1) maximum conductance at Vj = 0 and symmetrical gj reduction in response to positive and negative Vj of low amplitude, with little residual conductance; and 2) gj increases in response to simultaneous depolarization of the paired cells. The formation of hybrid channels, comprising Cx45 hemichannels from different species, allowed us to infer that two separate gates exist, one in each hemichannel, and that each Cx45 hemichannel is closed by the negativity of Vj on its cytoplasmic side. Interestingly, the Vm dependence of hybrid channels also suggests the presence of two gates in series, one Vm gate in each hemichannel. Thus the Vj and Vm dependence provides evidence that two independent voltage gates in each Cx45 hemichannel exist, reacting through specific voltage sensors and operating by different mechanisms, properties that have evolved divergently among species.

Detection of Treponema pallidum by a sensitive reverse transcriptase PCR

Syphilis is diagnosed by serologic testing or by identification of the causative agent, Treponema pallidum. The bacterium has historically been detected in clinical specimens by dark-field microscopy, immunostaining with polyclonal or monoclonal antibodies, or the rabbit inoculation test (RIT). RIT is considered to be very sensitive and specific, although it is available only in research settings and is not clinically useful due to the length of time required to obtain a result. In recent years, several PCR methods have been developed for the detection of T. pallidum, but none of these has shown a clear advantage in sensitivity over RIT. We have developed a specific and highly sensitive reverse transcriptase PCR (RT-PCR) that targets a 366 bp region of the 16S rRNA of T. pallidum. This RT-PCR can detect a single organism by Southern analysis when whole organisms are diluted and 10(-2) to 10(-3) T. pallidum organisms when RNA equivalents are used to make cDNA. The test was demonstrated to detect 10(-2) T. pallidum RNA equivalents in cerebrospinal fluid. Twenty different strains of T. pallidum, isolated from cerebrospinal fluids, aqueous humor, blood, and chancres, were shown to be detectable by this test. This efficient and sensitive technique could be more useful than existing methods for detecting very low numbers of organisms in clinical samples.

[Wine and health. Epidemiological studies and possible mechanisms of the protective effects]

Epidemiological studies show that moderate alcohol consumption, particularly wine, is associated to a decreased risk of ischemic heart disease death. A series of in vitro observations also support this association. Low density lipoproteins (LDL) oxidation apparently plays a key pathogenic role. Wine contains compounds with antioxidant capacity that could account for its postulated stabilizing effect on LDL. Furthermore, in human volunteers wine increases plasma total antioxidant capacity. Other additional effects also contribute to decrease the risk of ischemic heart disease: increased HDL cholesterol, and decreased blood coagulation. In another series of observations, moderate alcohol consumption has been associated with decreased physical and mental deterioration in elderly people. However, it is still under analysis if exaggerated alcohol consumption does increase the incidence of some cancers. On the whole, the presently available evidences clearly indicate that the positive effects associated to moderate wine or alcohol consumption, predominate over the negative effects. In fact, it seems reasonable to reassure moderate alcohol consumers that their cardiovascular death risk is lower; yet there are not enough studies to recommend moderate drinking to non-drinkers.

Urinary calcium excretion in healthy school children

Two hundred and twenty Argentinian primary school children (122 boys, 98 girls, aged 6-13 years) were studied to establish reference values of 24-h urinary calcium excretion (UCa) and calcium/creatinine ratio (Ca/Cr) in 24-h urine collections and in first-morning urine samples. Mean UCa excretion was 2.05 +/- 1.40 mg/kg per day and the 95th percentile was 4.74 mg/kg per day. UCa excretion was higher in boys than girls (2.33 +/- 1.47 and 1.70 +/- 1.24 mg/kg per day respectively, P < 0.001). Statistically significant differences were found between the 6- to 9-year and the 10- to 13-year age groups (2.37 +/- 1.49 vs. 1.73 +/- 1.25 mg/kg per day, P < 0.001). Mean Ca/Cr ratios in 24-h collections and in first-morning urine samples were 0.129 +/- 0.086 and 0.105 +/- 0.079 for the group overall (P < 0.001). The Ca/Cr ratio in the first-morning urine sample correlated poorly with the 24-h calcium excretion, suggesting that the Ca/Cr ratio in first-morning urine samples cannot replace the 24-h measurement.

Conservation of the 15-kilodalton lipoprotein among Treponema pallidum subspecies and strains and other pathogenic treponemes: genetic and antigenic analyses

The 15-kDa lipoprotein of Treponema pallidum is a major immunogen during natural syphilis infection in humans and experimental infection in other hosts. The humoral and cellular immune responses to this molecule appear late in infection as resistance to reinfection is developing. One therefore might hypothesize that this antigen is important for protective immunity. This possibility is explored by using both genetic and antigenic approaches. Limited or no cross-protection has been demonstrated between the T. pallidum subspecies and strains or between Treponema species. We therefore hypothesized that if the 15-kDa antigen was of major importance in protective immunity, it might be a likely site of antigenic diversity. To explore this possibility, the sequences of the open reading frames of the 15-kDa gene have been determined for Treponema pallidum subsp. pallidum (Nichols and Bal-3 strains), T. pallidum subsp. pertenue (Gauthier strain), T. pallidum subsp. endemicum (Bosnia strain), Treponema paraluiscuniculi (Cuniculi A, H, and K strains), and a little-characterized simian isolate of Treponema sp. (Fribourg-Blanc strain). No significant differences in DNA sequences of the genes for the coding region of the 15-kDa antigen were found among the different species and subspecies studied. In addition, all organisms showed expression of the 15-kDa antigen as determined by monoclonal antibody staining. The role of the 15-kDa antigen in protection against homologous infection with T. pallidum subsp. pallidum Nichols was examined in rabbits immunized with a purified recombinant 15-kDa fusion protein. No alteration in chancre development was observed in immunized, compared to unimmunized, rabbits, and the antisera induced by the immunization failed to enhance phagocytosis of T. pallidum subsp. pallidum by macrophages in vitro. These results do not support a major role for this antigen in protection against syphilis infection.

Two 16S-23S ribosomal DNA intergenic regions in different Treponema pallidum subspecies contain tRNA genes

The 16S-23S intergenic spacers of Treponema pallidum subspecies pallidum, Nichols strain, and Treponema pallidum subspecies pertenue, Gauthier strain, have been cloned, characterized and sequenced. Isoleucine and alanine tRNA genes have been identified within the 16S-23S intergenic regions on separate alleles of 293 and 303 bases, respectively. The two alleles are present in both T.p.pallidum and T.p. pertenue, and show no sequence differences between the bacterial subspecies. The ile-tRNA and ala-tRNA genes show 65% and 84% sequence identity, respectively, with the homologous genes of the related spirochete, Borrelia burgdorferi.

Comparison of methods for the detection of treponema pallidum in lesions of early syphilis

BACKGROUND

The clinical diagnosis of primary and secondary syphilis can be difficult because of the wide variability of lesions. The available laboratory tests (dark-field microscopy and direct fluorescent antibody) require specialized microscopes and skilled technicians, and serologic tests are insensitive in early infection.

METHODS

Dark-field microscopy and monoclonal antibody staining were compared to a new solid-phase enzyme-linked immunosorbent assay (Visuwell test) for detection of T. pallidum in lesion exudate of 188 patients with genital lesions.

RESULTS

Sixty-four patients (34%) had lesions of early syphilis diagnosed by either dark-field, monoclonal antibody staining, or both. The Visuwell test and dark-field examination were positive in 52 (81.3%) and 55 (85.9%) of the 64 patients, respectively, whereas the monoclonal antibody staining technique demonstrated the presence of T. pallidum in 59 (92.2%) of the 64 patients. The Visuwell test gave a negative result in 111 of 124 patients who had negative dark-field and direct fluorescent antibody test results (89.5% specificity).

CONCLUSIONS

The Visuwell test is an alternative method for evaluating genital ulcers but is less sensitive and specific than existing tests.

[Ultrasonographic (intra- and extraluminal) pattern of cervico-urethral anastomosis after radical prostatectomy]

Thirteen patients, mean age 61 years (range 54 to 71), diagnosed with prostate adenocarcinoma underwent radical prostatectomy. To achieve a diagnosis they were all performed blood PSA determination, digital rectal examination, transrectal ultrasound and a prostate ultrasound-guided biopsy by automatic gun puncture. Serum PSA quantification, digital rectal examination and transrectal ultrasound were repeated in the immediate post-operative, and three and six months after surgery. Through the information obtained with endocavitary ultrasound, the lumen of the cervicourethral anastomosis and the perianastomotic tissue was assessed. Transrectal ultrasound plays a relevant role in the follow-up of patients undergoing radical prostatectomy. When a patient with prostate radical surgery shows an elevation of serum PSA and/or abnormal digital rectal examination, an ultrasound-guided biopsy (at the node or perianastomotic area) is indicated.

Progesterone does not alter sympathetic activity in tissues involved in energy balance

Female rats acclimated to thermoneutrality to avoid cold influences received progesterone by means of subcutaneous implants. They increased their food intake and body weight above the values recorded in control animals. None the less, despite the enhanced food intake, no sign of activation of the sympathetic nervous system was observed, as judged by the unaltered noradrenaline content, half-life and turnover rate in brown adipose tissue, pancreas and heart. This indicates that progesterone increases food intake but prevents non-energy-conservation processes regulated by the sympathetic nervous system from taking place. Thus, it facilitates in two different ways the building up of energy stores. Because overfeeding induced by palatable diets increases the sympathetic tone to the organs studied, it is suggested that the central mechanisms regulating energy balance are probably influenced in a different manner by progesterone than by the sensory properties of palatable diets.

[Ureterosigmoidostomy detubularized with surgical staplers: C.F.C. (Original technique)]

Description of our modification of the detubulized ureterosigmoidostomy surgical technique (Castiñeiras-Ferragut-Camacho). In an attempt to shorten the surgery time, we used for these changes absorbable mechanical sutures (Poli Gia and T.A.). This paper analyzes the technical details of interest as well as the anatomicosurgical considerations that should be known prior to carry out this type of by-pass. The anatomicophysiological principles on which our developments are based are those referred by N.G. Kock15 and used by R. Hohenfellner and R. Fisch14, when they described the detubulized ureterosigmoidostomy performed manually. We believe that both surgical procedures, R. Hohenfellner & R. Fisch14 and ours (detubulized ureterosigmoidostomy, C.F.C.), are suitable alternatives to conventional ureterosigmoidostomy.

Laparoscopic treatment of esophageal achalasia

An observational cohort study evaluated the initial results of using laparoscopic-approach cardioesophageal myotomy with Dor-type anterior fundoplicature for esophageal achalasia. The study involved our first 12 patients: five men and seven women whose median age was 51 years. Esophageal motility was vigorous in four patients; the other eight had aperistalsis. Conversion to laparotomy was required in one case. No postoperative mortality occurred. Postoperative complications included one left subdiaphragmatic abscess secondary to perforation of the esophageal mucosa, which was sutured. Median postoperative hospital stay was 5 days (confidence interval, 4.7-6.7 days). Symptom relief (disappearance of dysphagia) was recorded in 10 cases; relief with partial persistence of dysphagia was observed in the remaining two patients, who were treated by postoperative dilatation. As to the postoperative manometric results, the median basal pressure of the lower esophageal sphincter was reduced from 26.3 mm Hg preoperatively to 15.5 mm Hg postoperatively, with a tendency toward statistical significance (p = 0.08); the median esophageal isotopic retention after 15 min decreased from 60% preoperatively to 24.5% after surgery, with a tendency toward statistical significance (p = 0.07). Cardiomyotomy with Dor fundoplicature through a laparoscopic approach seems effective in treating esophageal achalasia.

Isolation of a species-specific mitochondrial DNA sequence for identification of Tilletia indica, the Karnal bunt of wheat fungus

Mitochondrial DNA (mtDNA) from five isolates of Tilletia indica was isolated and digested with several restriction enzymes. A 2.3-kb EcoRI fragment was chosen, cloned, and shown to hybridize with total DNA restricted with EcoRI from T. indica and not from a morphologically similar smut fungus, Tilletia barclayana. The clone was partially sequenced, and primers were designed and tested under high-stringency conditions in PCR assays. The primer pair Ti1/Ti4 amplified a 2.3-kb fragment from total DNA of 17 T. indica isolates from India, Pakistan, and Mexico. DNA from 25 isolates of other smut fungi (T. barclayana, Tilletia foetida, Tilletia caries, Tilletia fusca, and Tilletia controversa) did not produce any bands, as detected by ethidium bromide-stained agarose gels and Southern hybridizations. The sensitivity of the assay was determined and increased by using a single nested primer in a second round of amplification, so that 1 pg of total mycelial DNA could be detected. The results indicated that the primers which originated from a cloned mtDNA sequence can be used to differentiate T. indica from other Tilletia species and have the potential to identify teliospores contaminating wheat seeds.

Papulacandin B resistance in budding and fission yeasts: isolation and characterization of a gene involved in (1,3)beta-D-glucan synthesis in Saccharomyces cerevisiae

Papulacandin B, an antifungal agent that interferes with the synthesis of yeast cell wall (1,3)beta-D-glucan, was used to isolate resistant mutants in Schizosaccharomyces pombe and Saccharomyces cerevisiae. The resistance to papulacandin B always segregated as a recessive character that defines a single complementation group in both yeasts (pbr1+ and PBR1, respectively). Determination of several kinetic parameters of (1,3)beta-D-glucan synthase activity revealed no differences between S. pombe wild-type and pbr1 mutant strains except in the 50% inhibitory concentration for papulacandin B of the synthases (about a 50-fold increase in mutant activity). Inactivation of the synthase activity of both yeasts after in vivo treatment with the antifungal agent showed that mutant synthases were more resistant than the corresponding wild-type ones. Detergent dissociation of the S. pombe synthase into soluble and particulate fractions and subsequent reconstitution indicated that the resistance character of pbr1 mutants resides in the particulate fraction of the enzyme. Cloning and sequencing of PBR1 from S. cerevisiae revealed a gene identical to others recently reported (FKS1, ETG1, CWH53, and CND1). Its disruption leads to reduced levels of both (1,3)beta-D-glucan synthase activity and the alkali-insoluble cell wall fraction. Transformants containing the PBR1 gene reverse the defect in (1,3)beta-D-glucan synthase. It is concluded that Pbr1p is probably part of the (1,3)beta-D-glucan synthase complex.

Sequence and functional analysis of the Streptomyces phaeochromogenes plasmid pJV1 reveals a modular organization of Streptomyces plasmids that replicate by rolling circle

pJV1 is an 11 kb, high-copy-number conjugative Streptomyces phaeochromogenes plasmid that replicates by the rolling circle mechanism (RCR). Sequencing combined with functional analysis of deletion, insertion and frameshift mutations was used to characterize the genes involved in plasmid transfer and chromosome mobilization (Cma), the single-strand origin for RCR and an associated strong incompatibility (Sti) determinant. pJV1 contains two essential transfer genes whose expression is regulated by an adjacent repressor gene with similarity to the GntR family of regulators. A consensus sequence specific for the helix-turn-helix motifs of repressor proteins of Streptomyces plasmids is proposed. Unregulated expression of the transfer genes by inactivation of the repressor is lethal. Three additional genes increase intramycelial plasmid spread resulting in pock formation but, unlike the essential transfer genes, are not required for Cma. The pJV1 transfer genes and their regulatory region, but not the minimal replication region encoding the double-strand replication origin and replication protein, are similar in their sequence and arrangement to those of the Streptomyces nigrifaciens plasmid pSN22, revealing a modular organization of Streptomyces RCR plasmids.

[Digestive hemorrhage and hemoperitoneum as complications of visceral aneurysms]

Two cases of visceral aneurysm are reported, one of the splenic artery and another of the gastroepiploic artery. The reason for the publication is the rarity, especially of aneurysms of the gastroepiploic artery, and because of the unusual presentations as upper gastrointestinal hemorrhage and hemoperitoneum respectively. The splenic artery aneurysm was diagnosed by CAT scan and the gastroepiploic one during emergency laparotomy because of the hemodynamic disturbance.

[Effectiveness of aminosidine sulphate in severe visceral leishmaniasis, resistant to the treatment with pentavalent antimony]

A grave kala-azar infection in a 14 years old boy is described. The leishmanial infection failed to respond to ten interrupted courses of glucantime of variable duration (14-56 days) at a dose of 20mg Sb5/kg/day. However a favorable response occurred to intramuscular aminosidine sulphate (20mg/kg/day) for 20 days. This same regimen was repeated 20 days later. After the first treatment splenic puncture parasite density fell from 50 amastigotes per oil immersion field to 3 amastigotes in 10 fields. A further splenic puncture 7 months after treatment was negative. The marked hepatoesplenomegaly gradually resolved over 26 months follow up and he gained 13 kilograms in weight. After aminosidine sulphate therapy his Montenegro reaction become positive and his lymphocytes responded to leishmania antigens.

[Complications of ultrasound-guided transperineal puncture biopsy of the prostate]

Between June 1988 and February 1993, 520 ultrasound-guided transperitoneal prostate biopsy punctures were performed in patients with prostate disease. Of these, 89 (17.1 %) were positive for malignancy. An analysis is made of the highly uncommon complications observed, which corresponded to 17 cases of haematuria (3.26%) and 3 of fever (0.5%). Likewise, reference is made to perineal neoplastic implantation, since such complication was evident in one of the cases contributed (0.19%). Also, a review of the literature relative to the complications is made, concluding by stating the relevance of this diagnostic technique in spite of said complications.

[Head circumference in Chilean school children 5 to 18 years of age and socioeconomic status]

The objectives of this study were to determine the head circumference (HC) values of a representative sample of 4,346 school children aged 5 to 18 years from Chile's Metropolitan Region, to carry out a comparative study with international reference data of Tanner, Nellhaus and Roche et al and to compare the HC values by socioeconomic status (SES). The sample included school children of both sexes, from public, private subsidized and private non-subsidized schools and from urban and rural areas. HC was measured according to Jelliffe norms and SES through Graffar's Modified Method. Results showed a high correlation between HC values of school-age children from Chile's Metropolitan Region and Tanner, Nellhaus and Roche et al Tables, with similar growth curves; from this manner, HC values of school-age children from Chile's Metropolitan Region not differ significantly from international reference data. HC values were, in general, significantly higher in males than females in all age groups, in students from high SES to compare with other socioeconomic strata and in older school children. This fact was tested too in 1992, in a representative sample of 605 poor school children beneficiaries from the School Feeding Program in Peñalolen and Pirque Counties from Chile's Metropolitan Region with similar results. It can be concluded that HC values of school-age children from Chile's Metropolitan Region were higher in males than females, in high SES compared with medium and low SES and in older students and does not differ significantly from international reference data.

[Nutritional status of school children in poverty conditions from urban and rural areas. Metropolitan region. Chile. 1986-1987]

The aim of this study was to compare the nutritional status of poor children from urban and rural areas and to quantify the impact of socioeconomic, sociocultural and family variables on nutritional status. Weight/age, height/age, weight/height and head circumference percentages were measured in a representative sample of 4509 school children, 39% belonging to a low socioeconomic status and living in the Metropolitan region, chosen according to grade, type of school, sex and geographic area. Children coming from rural areas had significantly higher percentages of undernutrition than children from urban areas according to weight/age (47 vs 34%, and weight/height (7.7 vs 4.6%); likewise they had a higher proportion of height/age ratios below 90% (10.3 vs 5.2%). Head circumference was below 100% in 77 and 65% of rural and urban children. Brachial anthropometric variables were also lower in rural children. The number of siblings and family size were the independent variables with the greatest explanatory power for weight/age and height/age variations. Mother's instruction in urban areas and crowding, family alcoholism and mother's instruction in rural areas, were the independent variables with the greatest explanatory power for head circumference variation. It is concluded that the significant relationship found between socioeconomic, sociocultural and family variables ad nutritional status is relevant, considering that the sample was homogeneous in each geographic area.

[Clinical features, diagnosis, and treatment of tumor lesions arising in the adrenal gland]

Between 1981 and 1993, 14 patients with tumoral adrenal disease were diagnosed and treated in the Urology Services of both Hospitals. Nature of the adrenal disease was functional in 8 patients (two carcinomas and six pheochromocytomas) and non-functional in the rest (three carcinomas, two adenomas and one myelolipoma). Reference is made to the clinical manifestations and laboratory tests related to hormonal activity, depending on whether the tumour is functional or non-functional, chromaffin or non-chromaffin. Patients with functional carcinomas had Cushing's syndrome, with very clear virtilization signs. Urine 17-hydroxycorticosteroid, 17-cetosteroides and cortisol were all increased, same as plasma cortisol. Patients with pheochromocytomas had hypertension and headaches (six patients), sweating (five patients), anxiety (four patients) and loss of weight (two patients). All of them had increased urine vainillylmandelic acid and catecholamines. Clinical signs and symptoms of non-functional tumours were related to bulk growth and size (in the three carcinomas), and sometimes was highly anodyne, or even absent (in the two adenomas and the myelolipoma), the cause of discovery being accidental during an ultrasound examination. An analysis is made of the different imaging diagnostic procedures performed, such as IVU (performed in 13 patients) with a 38.4% resolutory power; ultrasound (performed in 11 patients) with an 81.8% resolution; CAT (performed in 6 patients) with a 100% resolution capacity and arteriography (performed in 3 patients) with a 100% resolution power, although patients had previously undergone ultrasound and CAT.(ABSTRACT TRUNCATED AT 250 WORDS)

[Paratesticular neoplasms of mesenchymatous origin. Clinico-pathologic study]

There is a group of malignant intrascrotal tumours which represent a very small number when compared to testicular neoplasias and which are known as paratesticular neoplasias. More than 90% belong to the sarcomatous species. From a clinical point of view and based on the patient's age, two groups can be distinguished: sarcomas affecting children and adolescents (primarily rabdomiosarcomas) and those occurring in adulthood, the more frequent histopathological variants being fibrosarcoma, leiomiosarcoma and liposarcoma. This work contributes five paratesticular sarcomas (two rabdomiosarcomas, one liposarcoma, one leiomiosarcoma and one fibrosarcoma). The features related to histogenesis, diagnosis (revealing signs and clinical examination), natural history (dissemination routes based on histopathology) and treatment are reported. With regard to treatment, both the local surgery (total orchiectomy by inguinoscrotal approach with or without hemiscrotectomy), and indications for lymphadenectomy and radiotherapy in relation to staging are discussed though insisting on the chemotherapy approach.

[Longitudinal radiologic study of the esophagus, in an endemic area of Chagas disease, in a period of 13 years]

A radiological study of the oesophagus of a cohort of patients was carried during a 13 year period in the municipality of Mambaí Goiás. Barium swallow findings were recorded on 70mm film using a portable machine. Of 731 patients examined 382 (52.3%) were seropositive for T. cruzi. The sexes were equally divided. The incidence of detectable megaoesophagus was 7.9% among the cohort and 14.2% in the seropositive individuals. Progression of the disease was noted during this longitudinal study in 21.7% of males and 16.6% of females.

Reduced oxygen consumption of brown adipocytes isolated from progesterone-treated rats

It has been previously shown that responsiveness to noradrenaline is reduced in brown adipocytes isolated from estradiol-treated rats. The possibility that high plasma levels of progesterone could also alter adrenergic response was checked. The oxygen consumption of brown adipocytes isolated from control and progesterone-treated rats was monitored in basal conditions and in the presence of increasing concentrations of noradrenaline. In both situations, cells isolated from treated animals showed a lower respiratory rate than those from control animals. These results suggest that not only estradiol but also progesterone could modulate the adrenergic response of brown adipocytes. The study of alpha 1- and beta-adrenergic responses indicates that the beta-response parallels the general reduction in oxygen consumption, although the alpha 1-response seems to be more deeply depressed. Estimation of cell number in brown fat depots indicates some hyperplasia induced by progesterone; this increase in cell number could counterbalance partially but not totally the decreased cellular oxygen consumption at the organ level.

Sequence of the Streptomyces albus G lipase-encoding gene reveals the presence of a prokaryotic lipase family

An extracellular lipase (Lip)-encoding gene from Streptomyces albus G has been cloned and sequenced. It encodes a Lip with 82% sequence identity to another previously cloned Lip from a Streptomyces species not closely related. These two sequences can be aligned with 33% identity to the sequence of Lip1 from the antarctic psychrotroph Moraxella TA144 [G. Feller et al., Nucleic Acids Res. 18 (1990) 6431]. An alignment of the three sequences revealed amino-acid substitutions which might be responsible for the greater thermal stability of the Streptomyces lipases. The presence of this lip gene family in several members of the Streptomyces genus was also shown.

[A longitudinal radiologic study of the esophagus in an endemic area of Chagas' disease over a 6-year period]

A longitudinal study over six years was undertaken of 494 residents of the municipality of Mambaí, Goiás. Two hundred and twelve (43%) were seropositive in 1975/76 and 199 of 464 of the same patients group, positive in 1980/82 (42.8%). At both examination single radiographs of the oesophagus were obtained immediately after ingestion of 75 ml of barium sulphate solution and a second X-ray taken one minute later. Among the 201 seropositive patients without megaesophagus in the first study 4 (2%) evolved megaesophagus during the six years of observation. During this time, using Rezende's classification, patients with established megaesophagus, changed their group in the following manner. Only one Group I patient changed to group II. Only one group II patient progressed to group IV. Progress of megaesophagus in the affected patients occurred in 2.8% of 212 patients. Also four patients with grade I megaesophagus initially had a normal oesophagogram on the follow up examination. Ten patients had doubtful oesophagogram initially and six on follow up, 75% of these patients were seropositive. This study could indicate that a doubtful oesophagogram is an early sign of megaoesophagus.

[A mortality study in the Internal Medicine Emergency Service of October 12 Hospital during 1989]

152,902 patients were attended at the Emergency Department of "12 de Octubre" Hospital during 1989; 48,701 of them were seen in the Internal Medicine area. 196 dead, 164 case histories were selected in order to fulfil the protocol. Several variants were analysed, such as age, sex, diagnosis, time spent at the hospital, quality of life, date, etc. 53.6% were male; the median age was 73 years and the overall median age of all patients seen was 55.9 years. Median Karnovsky was 52.50% of the patients died during their first 5 hours at the Emergency Department. The most frequent diagnoses for the area were neurological, followed by cardiovascular, oncological, digestive, etc. The most frequent diseases observed were cerebrovascular accident, cardiac insufficiency and acute infarction, oncological cases and death on arrival. Mortality was higher in winter. On the whole, mortality was higher in oncology patients followed way behind by neurology digestive and cardiovascular patients.

Normative data on the Boston Diagnostic Aphasia Examination in a Spanish-speaking population

Normative data of the Boston Diagnostic Aphasia Examination (Goodglass & Kaplan, 1972) in a Spanish-speaking population is presented. This test was given to 180 neurologically normal adults grouped according to three variables: sex, age, and educational level. The statistically significant differences found are presented. Few differences appeared between sexes, but there were marked differences among the different age groups and in particular among educational levels. A correction to the scoring is proposed for each of the subtests according the patient's educational level.

Trypanosoma (Schizotrypanum) cruzi: repetitive DNA sequence evolution in three geographically distinct isolates

1. Middle-repetitive DNA sequences were analyzed by molecular hybridization to determine both the extent of complementarity and time of evolutionary divergence between isolates of Trypanosoma cruzi from Argentina, Mexico, or Venezuela. 2. Although molecular hybridizations showed no significant difference between the middle-repetitive DNAs of the Mexican and Venezuelan isolates, there was a 2.7% base pair mismatch in hybrid molecules formed by association of strands from both the Mexican and Argentine isolates. 3. Using the rates for divergence of middle-repetitive DNA in sea urchins, the Mexican and Argentine isolates were estimated to have diverged approximately 20-25 million years ago. 4. Analysis of the kinetics for the DNA hybridizations indicates that only minor amplifications of specific gene sequences or changes in the complexity of the genomes could have occurred during the divergence of the three isolates studied.

Treatment of transitional cell carcinoma of the ureter: is the controversy justified?

Between 1938 and 1985, 73 patients with ureteral tumors underwent surgery at Puigvert Foundation (1 case with bilateral synchronous tumors). Sixty-three patients were males and 10 females. Ages ranged between 49 and 78 (mean of 62) years. Tumoral stages were: pTa 5 cases; pT1 56 cases; pT2 10 cases, and pT3 2 cases. Radical treatment was performed in 38 cases and conservative treatment in 35 cases. Follow-up ranged between 2 and 20 (mean of 7) years. The overall survival rate at 5 years was 100, 82 and 50% for stages pTa, pT1 and pT2-3, respectively (p less than 0.05). Analyzed together, the actuarial survival at 5 years was 90.3% with conservative surgery and 67.8% with radical surgery (p not significant). The survival by stages for the patients treated with radical surgery was: 100% in pTa; 69.6% in pT1, and 57.1% in pT2-3. For those treated conservatively, survival was 100% in pTa, 95.8% in pT1 and 33.3% in pT2. Thus patients presenting with infiltrating tumors should not be treated conservatively, while patients with superficial lesions had a similar evolution whether treated by conservative or radical surgery.