Production of nucleic acid-related substances by Aspergillus niger in chemically defined media

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Produção de substâncias relacionadas a ácidos nucleicos por Streptomyces aureofaciens em meios complexos

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Genes involved in lactose catabolism and organic acid production during growth of Lactobacillus delbrueckii UFV H2b20 in skimmed milk

There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh – lactate dehydrogenase, adhE – Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 – catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property for pizza cheeses.

Genes involved in protein metabolism of the probiotic lactic acid bacterium Lactobacillus delbrueckii UFV H2b20

A basic requirement for the prediction of the potential use of lactic acid bacteria (LAB) in the dairy industry is the identification of specific genes involved in flavour-forming pathways. The probiotic Lactobacillus delbrueckii UFV H2b20 was submitted to a genetic characterisation and phylogenetic analysis of genes involved in protein catabolism. Eight genes belonging to this system were identified, which possess a closely phylogenetic relationship to NCFM strains representative, as it was demonstrated for oppC and oppBII, encoding oligopeptide transport system components. PepC, PepN, and PepX might be essential for growth of LAB, probiotic or not, since the correspondent genes are always present, including in L. delbrueckii UFV H2b20 genome. For pepX gene, a probable link between carbohydrate catabolism and PepX expression may exists, where it is regulated by PepR1/CcpA-like, a common feature between Lactobacillus strains and also in L. delbrueckii UFV H2b20. The well conserved evolutionary history of the ilvE gene is evidence that the pathways leading to branched-chain amino acid degradation, such as isoleucine and valine, are similar among L. delbrueckii subsp. bulgaricus strains and L. delbrueckii UFV H2b20. Thus, the involvement of succinate in flavour formation can be attributed to IlvE activity. The presence of aminopeptidase G in L. delbrueckii UFV H2b20 genome, which is absent in several strains, might improve the proteolytic activity and effectiveness. The nucleotide sequence encoding PepG revealed that it is a cysteine endopeptidase, belonging to Peptidase C1 superfamily; sequence analysis showed 99% identity with L. delbrueckii subsp. bulgaricus ATCC 11842 pepG, whereas protein sequence analysis revealed 100% similarity with PepG from the same organism. The present study proposes a schematic model to explain how the proteolytic system of the probiotic L. delbrueckii UFV H2b20 works, based on the components identified so far.

Functional and ultrastructural neuroanatomy of interactive intratectal/tectonigral mesencephalic opioid inhibitory links and nigrotectal GABAergic pathways: Involvement of GABAA and μ1-opioid receptors in the modulation of panic-like reactions elicited by electrical stimulation of the dorsal midbrain

In the present study, the functional neuroanatomy of nigrotectal-tectonigral pathways as well as the effects of central administration of opioid antagonists on aversive stimuli-induced responses elicited by electrical stimulation of the midbrain tectum were determined. Central microinjections of naloxonazine, a selective mu(1)-opiod receptor antagonist, in the mesencephalic tectum (MT) caused a significant increase in the escape thresholds elicited by local electrical stimulation. Furthermore, either naltrexone or naloxonazine microinjected in the substantia nigra, pars reticulata (SNpr), caused a significant increase in the defensive thresholds elicited by electrical stimulation of the continuum comprised by dorsolateral aspects of the periaqueductal gray matter (dlPAG) and deep layers of the superior colliculus (dlSC), as compared with controls. These findings suggest an opioid modulation of GABAergic inhibitory inputs controlling the defensive behavior elicited by MT stimulation, in cranial aspects. In fact, iontophoretic microinjections of the neurotracer biodextran into the SNpr, a mesencephalic structure rich in GABA-containing neurons, show outputs to neural substrate of the dlSC/dlPAG involved with the generation and organization of fear- and panic-like reactions. Neurochemical lesion of the nigrotectal pathways increased the sensitivity of the MT to electrical (at alertness, freezing and escape thresholds) and chemical (blockade of GABA(A) receptors) stimulation, suggesting a tonic modulatory effect of the nigrotectal GABAergic outputs on the neural networks of the MT involved with the organization of the defensive behavior and panic-like reactions. Labeled neurons of the midbrain tectum send inputs with varicosities to ipsi and contralateral dlSC/dlPAG and ipsilateral substantia nigra, pars reticulata and compacta, in which the anterograde and retrograde tracing from a single injection indicates that the substantia nigra has reciprocal connections with the dlSC/dlPAG featuring close axo-somatic and axo-dendritic appositions in both locations. In addition, ultrastructural approaches show inhibitory axo-axonic synapses in MT and inhibitory axo-somatic/axo-axonic synapses in the SNpr. These findings, in addition to the psychopharmacological evidence for the interaction between opioid and GABAergic mechanisms in the cranial aspects of the MT as well as in the mesencephalic tegmentum, offer a neuroanatomical basis of a pre-synaptic opioid inhibition of GABAergic nigrotectal neurons modulating fear in defensive behavior-related structures of the cranial mesencephalon, in a short link, and through a major neural circuit, also in GABA-containing perikarya and axons of nigrotectal neurons.

Neuroanatomical and neuropharmacological study of opioid pathways in the mesencephalic tectum: effect of μ1- and κ-opioid receptor blockade on escape behavior induced by electrical stimulation of the inferior colliculus

Deep layers of the superior colliculus (DLSC), the dorsal and ventral periaqueductal gray matter (PAG), and inferior colliculus (IC) are midbrain structures involved in the generation of defensive behavior. beta-Endorphin and Leu-enkephalin are some neurotransmitters that may modulate such behavior in mammals. Light microscopy immunocytochemistry with streptavidin method was used for the localization of the putative cells of defensive behavior with antibodies for endogenous opioids in rat brainstem. Midbrain structures showed positive neurons to beta-endorphin and Leu-enkephalin in similar distributions in the experimental animals, but we also noted the presence of varicose fibers positive to endogenous opioids in the PAG. Neuroanatomical techniques showed varicose fibers from the central nucleus of the inferior colliculus to ventral aspects of the PAG, at more caudal levels. Naloxonazine and nor-binaltorphimine, competitive antagonists that block mu(1)- and kappa-opioid receptors, were then used in the present work to investigate the involvement of opioid peptide neural system in the control of the fear-induced reactions evoked by electrical stimulation of the neural substrates of the inferior colliculus. The fear-like responses were measured by electrical stimulation of the central nucleus of the inferior colliculus, eliciting the escape behavior, which is characterized by vigorous running and jumping. Central administration of opioid antagonists (2.5 microg/0.2 microl and 5.0 microg/0.2 microl) was performed in non-anesthetized animals (Rattus norvegicus), and the behavioral manifestations of fear were registered after 10 min, 2 h, and 24 h of the pretreatment. Naloxonazine caused an increase of the defensive threshold, as compared to control, suggesting an antiaversive effect of the antagonism on mu(1)-opioid receptor. This finding was corroborated with central administration of nor-binaltorphimine, which also induced a decrease of the fear-like responses evoked by electrical stimulation of the inferior colliculus, since the threshold of the escape behavior was increased 2 and 24 h after the blockade of kappa-opioid receptor. These results indicate that endogenous opioids may be involved in the modulation of fear in the central nucleus of the inferior colliculus. Although the acute treatment (after 10 min) of both naloxonazine and nor-binaltorphimine causes nonspecific effect on opioid receptors, we must consider the involvement of mu(1)- and kappa-opioid receptors in the antiaversive influence of the opioidergic interneurons in the dorsal mesencephalon, at caudal level, after chronic (2-24 h) treatment of these opioid antagonists. The neuroanatomical study of the connections between the central nucleus of the inferior colliculus and the periaqueductal gray matter showed neuronal fibers with varicosities and with terminal bottons, both in the pericentral nucleus of the inferior colliculus and in ventral and dorsal parts of caudal aspects of the periaqueductal gray matter.

Psychopharmacological evidences for the involvement of muscarinic and nicotinic cholinergic receptors on sweet substance-induced analgesia in Rattus norvegicus

In order to investigate the effects of sweet substance intake on pain modulation, male albino Wistar rats weighing 180-200 g received either tap water or sucrose solutions (250 g/l) for 14 days as their only source of liquid. Each rat consumed an average of 15.6 g sucrose/day. Their tail withdrawal latencies in the tail-flick test (probably a spinal reflex) were measured immediately before and after this treatment. An analgesia index was calculated from the withdrawal latencies before and after treatment. The index (mean +/- SEM, N = 8) for the groups receiving sucrose solution plus saline (NaCl; 0.9%) for 14 days was 0.70 +/- 0.01. Atropine (1 and 2 mg/kg)-treated rats (N = 8) after intake of sucrose exhibited an analgesia index of 0.39 +/- 0.09 and 0.39 +/- 0.08, respectively, while mecamylamine (1 and 2 mg/kg)-treated rats (N = 10) after intake of sucrose had an index of -0.02 +/- 0.07 and 0.03 +/- 0.07, respectively. These results indicate that the effect of sucrose intake on nociceptive thresholds is controlled by neurotransmission of acetylcholine and depends on the nicotinic cholinergic receptors for its major analgesic effect, although muscarinic receptors were also involved in this antinociceptive process.

[HCV genotypes. Liver histopathology and immunologic profile in four groups of patients]

AIM

Study on the prevalence of MCV genotypes, and correlation with liver pathology and immunological parameters.

PATIENTS AND METHODS

77 chronic hepatitis C patients (52 males, 25 females), mean age 44 +/- 14 years, belonging to four groups: (1) 23 (11 males) without other aetiology, (II) 19 (18 males) excessive drinkers, (III) 18 (12 males) haemodialysed, (IV) 17 (11 males) renal transplantation patients Genotyping was done by PCR (primers of the core, and hybridisation with specific probes). Serum Igs A, G, and M (by nephelometry), and peripheral blood lymphocyte (PBL) subsets (by flow cytometry) were determined.

RESULTS

One genotype was found in 62 patients (1b 69.2%, 1a 21.5%, 2a 3.1%, 2b 3.1%, 3a 9.2%), and two genotypes in 4 patients (1b + 3a in 1 of group 1, 1b + 2a in 2 and 1a + 3a in 1 of group 111). Twelve cases (15.6%) were not identified (NI). Relative prevalence was not different in the four groups, but in 7 drug addicts 1 b was not found (Ia in 71.4%, 3 a 28.6%) The relationship between genotypes and age was significant (p < 0.05): in the 34 patients with less than 40 years, 1b was found in 38.2%, in the others in 41.2%, and NI in 20.6%; in those with 40-60 years, 1b was found in 68.8%, in the others in 15.6%, M in 15.6%; in those above 60 years, 1b was found in 90.9%, in the others in 9.1%. Of those identified, only genotype 1 (1a and 1b) was associated to moderate or severe activity, and infected 11/13 cases of cirrhosis or severe fibrosis. IgM (g/dL) was lower in 1b than in the others: 1.58 + 1.23 vs. 2.53 + 1.93 (p < 0.01). PBL (per mm3) were lesser in 1b than in the others, with significance for the CD8+: 540t239 vs. 739 + 420 (p < 0.01).

CONCLUSIONS

Genotype 1b was the most prevalent in Portuguese patients, more significantly in the elderly, and was absent in drug addicts. The prevalence of genotypes is similar in general patients, in chronic haemodialysed, in renal transplantation recipients and in alcoholics. More severe liver pathology was associated with 1b and 1a genotypes. IgM and CD8+ had lower mean values in 1b infected patients. Other genotypes are certainly important in Portugal.

Development of an ELISA to assess the potency of horse therapeutic polyvalent antibothropic antivenom

The objective of this study was the search for a suitable venom antigen to be used in an in vitro alternative immunoassay, to the standard antivenom neutralization assay using mice. Bothrops jararaca venom was fractionated in DEAE-Sephacel columns and the fractions were tested for a correlation between antibody capture enzyme linked immunosorbent assay (ELISA) absorbance values and the 'in vivo' antivenom potency. Individual antivenoms from 14 horses and 15 separate FUNED polyspecific Bothrops ampouled antivenoms (final product) were used. Fractions showing the higher correlations were further chromatographed in a Sephadex G-75 column and again tested for the correlation. Two fractions with haemorrhagic activity displayed a correlation of r = 0.77 and r = 0.8 against the individual horse antivenom sera and of r = 0.79 and r = 0.8 for the ampouled antivenom. For all results p < 0.001. Two other fractions with phospholipase A2 activity showed a correlation of r = 0.66 (p < 0.01) and r = 0.56 (p < 0.03) against the individual horse antivenom sera. Electrophoresis results show a similar composition for both antigens with haemorrhagic activity. Results indicate that the fractions purified would be suitable for the desired objective of this study.

Fractures of the spine in ankylosing spondylitis

Fractures through the disc or the vertebral body as well as the posterior elements are typically seen in ankylosing spondylitis. The fractures can be compared to the fractures of long bones and are often unstable. These fractures are usually associated with increasing pain and may be the result of minor traumas. The radiographic appearance may be discrete, but overlooking the fracture may have disastrous consequences. The characteristic features and the biomechanical pathogenesis of these fractures are reviewed.

[Hospital infections at an oncology hospital]

During 23 months, the authors analyzed 8122 records of cancer patients admitted to the National Institute of Cancer of Rio de Janeiro, Brazil. The rate of hospital infection was of 18.4 infection episodes per 100 admissions. Hospital infections were detected in 556 patients (57.7%) of the surgical department. The overall rate of purulence seen in 4194 surgeries was 10.1%, and among 2153 clean surgeries, the authors found 95 (4.4%) suppurated surgeries. The surgical wound (28.2%), the respiratory tract (19.2%), and the urinary tract (18.7%) were the major sites involved during infections episodes. Of the 319 ICU patients evaluated, 154 acquired infection after the first 72 hours, with a mortality rate of 48.7%. The hospital microbial flora was made-up mostly of gram-negative aerobic bacteria, with a high incidence of micro-organisms that resist to major antibiotics of hospital use. The percentage of positive results in blood culture tests requested was of 23.7%, with a predominance of gram-negative bacteria (50.9%) and a high percentage of gentamicin-resistant micro-organisms. Antibiotics of greater use in surgical interventions were amikacin, first generation cephalosporins, and chloramphenicol, whereas amikacin, carbenicillin, and first and third generation cephalosporins prevailed in nonsurgical treatments. The authors' experience and findings re-emphasize the need and the importance of a broad multidisciplinary understanding and suggest the need of strict action for an effective control and prevention in hospitals of developing countries.

Sclerotic changes of the sternal end of the clavicle

Five adult females with swelling, tenderness and similar sclerotic changes of the sternal end of the clavicle are presented. They were recognised during a 10-year period, suggesting that the condition is rare and may be misdiagnosed. In three patients strain of the sternoclavicular joint seemed to be an aetiological factor.

Degree of vertebral wedging of the dorso-lumbar spine

From a random sample consisting of 164 persons, the degree of vertebral wedging was calculated as the ratio between the heights of the anterior and posterior aspects of the vertebrae Th8 to L3. The normal values and confidence limits are described. The degree of wedging was significantly greater at almost all levels in the male group than in the female group. No positive relationship to age was found.

Identification of Low-Molecular-Weight Nucleic Acid-Related Substances Secreted by Streptomyces aureofaciens

Streptomyces aureofaciens growth in chemically defined medium is actively associated with the secretion of low-molecular-weight nucleic acid-related substances and is linked to low availability of phosphate. Thirteen pure compounds were isolated, of which seven were identified.

[The cribriform fossa of the sacrum. A source of abusive interpretation of osteolysis]

A number of X-ray pictures have been taken of a 29 years old man suffering from low back pains. The profile negative of these pictures imply an erosion on the forewall of the sacral canal, which is similar to a tumor destruction. The tomography refutes any bone destruction. On the contrary, it proves that there are some very deep riddled fossae of the sacrum, a frequent anatomic variant.

Sacroiliac joint involvement in classical or definite rheumatoid arthritis

In 188 patients with rheumatoid arthritis 564 radiologic examinations of the sacroiliac joints were performed. Severe blurring of the joint space or ankylosis were uncommon. The involvement was related to an age > 40 years at the onset, high values of the ESR and involvement of most joint groups in the limbs and cervical spine. Sex, presence or high titres of the rheumatoid factor and antinuclear antibodies were unrelated to lesions of the sacroiliac joints. A relation to the severity of rheumatoid arthritis rather than to the immunologic condition is suggested.