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Biomedical subjects

C Cruz

Publications and source records attributed to C Cruz.

At least 145 records · Page 8Linked to original sources
PubMed1991

Traumatic interhemispheric subdural haematomas.

According to reports in the literature traumatic interhemispheric subdural haematomas (I.S.H.) are supposed to present acutely or subacutely with contralateral monoparesis of a lower extremity or hemiparesis or in bilateral haematomas even with paraparesis, and to need early operative evacuation. In our series of 5 cases none of them followed this "classical" clinical picture, and three of them recovered without operation. We conclude that the indication for operative evacuation depends on the clinical course and that in patients with spontaneously improving symptomatology non-surgical management under close supervision may be the better solution. Also the C.T. finding of open convexity cisterns may be possible indication for conservative management.

Adolescent↗
PubMed1991

Comparative study of the fatty acid composition of sponges of the genus Ircinia. Identification of the new 23-methyl-5,9-tetracosadienoic acid.

1. The phospholipid fatty acid compositions of the sponges Ircinia strobilina, Ircinia felix, Ircinia campana, Ircinia sp., Spongia tubulifera and Dysidea etherea were studied, revealing the presence, besides other common fatty acids, of considerable amounts (2-5%) of the novel 23-methyl-5,9-tetracosadienoic acid (1). 2. The demospongic acids 5,9-tetracosadienoic acid, 23-methyl-5,9-tetracosadienoic acid (1), and 5,9-pentacosadienoic acid, were particularly abundant in sponges of the genus Ircinia, in contrast to the most common 5,9-hexacosadienoic acid found in other species. These findings are discussed in terms of the taxonomy of the Dictyoceratida. 3. The complete characterization of the novel phospholipid fatty acid 23-methyl-5,9-tetracosadienoic acid (1) is presented.

Animals↗
PubMed1991

Neuronal localization of pyroglutamate aminopeptidase II in primary cultures of fetal mouse brain.

Pyroglutamate aminopeptidase II is a highly specific membrane-bound ectopeptidase proposed to inactivate thyrotropin releasing hormone (TRH) in brain extracellular space. Its activity was measured in primary cell cultures of fetal brain in an attempt to define its cellular localization. Enzyme activity was detected in hypothalamic or cortical cell membrane fractions from 4- to 12-day-old cultures. When proliferation of nonneuronal cells was abolished by cytosine arabinoside treatment, pyroglutamate aminopeptidase II specific activity was increased as compared to untreated cultures, the opposite was observed for pyroglutamate amino-peptidase I activity. Treatment of cortical cells with the neurotoxic agent glutamate reduced simultaneously pyroglutamate aminopeptidase II and glutamate decarboxylase activities. Glial cell cultures expressed pyroglutamate aminopeptidase I or glutamate synthase activities but not pyroglutamate aminopeptidase II. The data suggest that pyroglutamate aminopeptidase II is predominantly localized in neuronal cells. This is consistent with a role for pyroglutamate aminopeptidase II in TRH-ergic synaptic transmission.

Animals↗
PubMed1991

Urinary excretion of renin and angiotensinogen in nephrotic rats.

Puromycin aminonucleoside (PA)-nephrotic rats have a high plasma renin activity (PRA) and low angiotensinogen levels. We measured proteinuria, urine renin, and urine angiotensinogen daily, for 11 days after PA injection. Proteinuria and urine angiotensinogen were evident on day 5, and urine renin on day 6. Peak levels of urine renin and angiotensinogen were attained on day 8. These data suggest that angiotensinogen urine excretion may contribute to its low plasma levels, and urine renin loss may limit a further increase in PRA.

Angiotensinogen↗
PubMed1991

Response of Weeksella virosa peritonitis to imipenem/cilastin.

CAPD peritonitis is most commonly due to gram positive infection. Gram negative bacillary infection is less frequent but is often seen in hospitalized patients or in those on antibiotics. Weeksella virosa (formerly known as Flavobacterium II F) has been isolated from the vaginal secretions and urine of normal women. As gram negative colonization typically proceeds from the perineal region, Weeksella virosa peritonitis might be expected in women at risk for gram negative peritonitis. A 33-year-old woman on CAPD developed multiply resistant Weeksella virosa peritonitis after prior hospitalization for pericarditis and antibiotic treatment for pneumonia. Cultures became negative and cell counts returned to normal during treatment with intravenous imipenem/cilastin. Curative treatment was completed with intraperitoneal imipenem/cilastin and oral ampicillin. Treatment was well tolerated despite theoretical concerns about the risk of seizures in patients with severe renal insufficiency not on hemodialysis.

Adult↗
PubMed1991

Testing the safety of non-disconnect disposable Y sets for peritoneal dialysis.

In order to test the efficacy of the Del Clamp as a contamination barrier, the following protocol was carried out. Sixty bags of dialysate (1.5 L, 1.5% Dextrose) were connected to matching disposable Y sets and 100 mL of dialysate allowed to flow into each drain bag, after which the clamps were closed. The bags were arranged in groups of 10 and each group was inoculated with 1 mL of a standard suspension of S. aureus, S. epidermidis, E. coli, E. faecalis, P. aeruginosa and C. albicans, respectively. 3 bags were inoculated and left with the clamp open as controls. After 6 hr, incubation at 37 degrees C, 20 mL duplicate samples from each drain bag were centrifugated and processed for anaerobic and aerobic culture. None of the specimens taken from the sets grew bacteria or fungi. All the drain bags of the control sets grew the inoculated organism. We conclude that the Del Clamp makes CAPD safer by working as an effective contamination barrier and eliminating a potential for combination during the dialysis exchange.

Bacteria↗
PubMed1991

[Clinical diagnosis versus autopsy].

Records from 910 autopsies performed at a university hospital in Salvador, Bahia, Brazil were examined in order to assess the accuracy of clinical diagnoses of the patients' underlying causes of death. This study found inaccurate clinical diagnoses in 31% of the cases. The overall rate of diagnostic error appeared to remain fairly stable from 1970 to 1982, being highest for older patients. Thirty-six percent of the 263 cancer deaths were incorrectly diagnosed, and a number of pathologies considered relatively easy to diagnose were not always correctly identified--the underlying cause of death being incorrectly diagnosed in many of the fatalities caused by such ailments as arterial hypertension, chronic obstructive lung disease, pneumonia/bronchopneumonia, and schistosomiasis. Quite aside from their direct medical implications, diagnostic errors of the magnitude observed in this and other studies seriously jeopardize the quality of vital statistics and such statistics' usefulness for improving public health.

Adolescent↗
PubMed1991

Clinical diagnosis versus autopsy.

Records from 910 autopsies performed at a university hospital in Salvador, Bahia, Brazil, were examined in order to assess the accuracy of clinical diagnoses of the patients' underlying causes of death. This study found inaccurate clinical diagnoses in 31% of the cases. The overall rate of diagnostic error appeared to remain fairly stable from 1970 to 1982, being highest for older patients. Thirty-six percent of the 263 cancer deaths were incorrectly diagnosed, and a number of pathologies considered relatively easy to diagnose were not always correctly identified. Quite aside from their direct medical implications, diagnostic errors of the magnitude observed in this and other studies seriously jeopardize the quality of vital statistics and such statistics' usefulness for improving public health.

Adolescent↗
PubMed1990

Angiotensin I-converting enzyme activity in puromycin aminonucleoside-nephrotic syndrome.

Puromycin aminonucleoside (PAN)-nephrotic rats have high serum angiotensin I-converting enzyme (ACE) activity. We studied ACE activity in serum, urine, and tissues from PAN-nephrotic rats on days 2, 6, 11, and 16 after PAN injection. Proteinuria and hypoproteinemia were evident on days 6 and 11. Though significantly decreased, proteinuria was still evident on day 16. Serum ACE activity increased on days 2, 6, and 11. Urinary ACE activity became evident on days 6, 11, and 16 and correlated positively with proteinuria, suggesting that the source of urine ACE is the blood serum. ACE activity increased in testis on days 2 and 6, in lungs and aorta on days 6 and 11, in adrenal glands and small intestine on day 11, and in kidney on days 11 and 16. Heart ACE activity decreased on days 2 and 6, and increased on day 16; brain ACE activity decreased on day 6 and increased on day 11. These data implicate that changes in tissue ACE content may contribute to elevate serum ACE in PAN-nephrotic rats.

Animals↗
PubMed1990

MutY, an adenine glycosylase active on G-A mispairs, has homology to endonuclease III.

The mutY gene of Escherichia coli, which codes for an adenine glycosylase that excises the adenine of a G-A mispair, has been cloned and sequenced. The mutY gene codes for a protein of 350 amino acids (Mr = 39,123) and the clone genetically complements the mutY strain. The protein shows significant sequence homology to E. coli endonuclease III, an enzyme that has previously been shown to have glycosylase activity on damaged base pairs. Sequence analysis suggests that, like endonuclease III, MutY is an iron-sulfur protein with a [4Fe-4S]2+ cluster.

Adenine↗
PubMed1990

Evaluation of the role of prolyl endopeptidase and pyroglutamyl peptidase I in the metabolism of LHRH and TRH in brain.

Intraneuronal peptide regulatory mechanisms are still poorly understood. The cytosolic enzymes prolyl endopeptidase (EC 3.4.21.26) and pyroglutamyl peptidase I (E.C.3.4.19.3) degrade both TRH and LHRH. Previous studies from this laboratory have not supported a role for these enzymes in the control of TRH levels. These studies have now been extended to cell and organ cultures and examine the effects of enzyme inhibition on LHRH. Exposure of dispersed hypothalamic cells or median eminences in culture to Z-Pro-Prolinal and pyroglutamyl diazomethyl ketone, specific inhibitors of prolyl endopeptidase and pyroglutamyl peptidase I respectively, did not change TRH content or recovery of released TRH. In vivo and in vitro treatment with these inhibitors did not modify the content of LHRH or recovery of this peptide upon release from several brain regions except in the olfactory bulb where an unexpected decrease in levels was observed. Olfactory bulb levels of TRH also decreased but only after prolonged in vivo inhibitor treatment. The decrease in olfactory bulb LHRH and TRH could not be accounted for by enzyme induction and is likely due to a non-specific or indirect effect of the inhibitors on the processing of these peptides. These studies demonstrate that levels of LHRH and TRH in brain are not controlled by cytosolic peptidases.

Animals↗
PubMed1990

Serotype-specific outbreak of group B meningococcal disease in Iquique, Chile.

From 1979 to August 1987, there have been 178 cases of meningococcal disease in Iquique, Chile, a city of about 140,000. The attack rate for the last 5 years has been in excess of 20/100,000 per year, more than 20 times greater than for the country overall. The mortality rate was 6%. The disease occurred in patients with ages from 4 months to 60 years, but 89% of cases were in patients less than 21 years. The largest number of cases were in the age group 5-9 years (n = 54), but the highest incidence occurred in children less than 1 year of age (72.8/100,000 per year). The male/female ratio was 1.2. Cases occurred all year round with little seasonal variation. Of the 178 cases, 173 were biologically confirmed. Serogroup analysis of strains from 135 patients revealed A = 1, B = 124, C = 10. Forty-four group B strains from 1985-7 were serotyped: 15:P1.3 = 36, 15:NT = 4, 4:P1.3 = 2, NT:NT = 2. Ten of 11 of the outbreak strains tested were sulfadiazine-resistant. This is the first recognized outbreak caused by a Gp B:15 strain in South America. It shares many of the characteristics of outbreaks caused by closely related strains in Europe, such as a predilection for older children and adolescents, sulfadiazine-resistance, and sustained high attack rates. The Iquique strain (B:15:P1.3) belongs to the same genetic clone (ET-5 complex) as the Norway (B:15:P1.16) and the Cuban (B:4:P1.15) strains.

Adolescent↗
PubMed1990

mutA and mutC: two mutator loci in Escherichia coli that stimulate transversions.

Two transversion-specific mutator loci, mutA and mutC, were identified in Escherichia coli. Mutators with high rates of A.T----T.A transversions were identified using a screening technique that relied upon the reversion of an altered lacZ gene back to wild-type via a specific A.T----T.A transversion. Among the mutators collected, one class mapped to a previously unidentified locus that we designate mutA. Analysis of reverse mutations in lacZ and forward nonsense mutations in lacI showed that the mutA strain has higher levels of A.T----T.A and G.C----T.A transversions, and to a lesser degree A.T----C.G transversions. The mutA locus maps very near to, but is separable from, mutL, at about 95 min on the E. coli chromosome. Both its mutagenic specificity and complementation experiments confirmed that mutA is distinct from mutL and from a nearby mutator locus, miaA. The phenotype of a mutA mutL double mutator strain suggests that the mutA gene product prevents some replication errors. Another mutator, designated mutC, maps very near uvrC, at 42 min, but is distinguishable from uvrC, which has no mutator effects. The specificity of reversion of lacZ mutations in a mutC strain is identical to that in a mutA strain. Also, the behavior of a mutC mutS double mutant is identical to that of a mutA mutL double mutant. It is likely that mutA and mutC are components of the same error-avoidance system.

Chromosome Mapping↗
PubMed1990

A set of lacZ mutations in Escherichia coli that allow rapid detection of specific frameshift mutations.

We have used site-directed mutagenesis to alter bases in lacZ near the region encoding essential residues in the active site of beta-galactosidase. The altered sequences generate runs of six or seven identical base pairs which create a frameshift, resulting in a Lac- phenotype. Reversion to Lac+ in each strain can occur only by a specific frameshift at these sequences. Monotonous runs of A's (or of T's on the opposite strand) and G's (or C's) have been constructed, as has an alternating -C-G- sequence. These specific frameshift indicator strains complement a set of six previously described strains which detect each of the base substitutions. We have examined a variety of mutagens and mutators for their ability to cause reversion to Lac+. Surprisingly, frameshifts are well stimulated at many of these runs by ethyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine and 2-amino-purine, mutagens not widely known to induce frameshifts. A comparison of ethyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine and 2-aminopurine frameshift specificity with that found with a mutH strain suggests that these mutagens partially or fully saturate or inactivate the methylation-directed mismatch repair system and allow replication errors leading to frameshifts to escape repair. This results in a form of indirect mutagenesis, which can be detected at certain sites.

Base Sequence↗
PubMed1990

Spinal cord hemangioblastoma with subarachnoid hemorrhage.

A case of subarachnoid hemorrhage caused by a cervical hemangioblastoma is presented. The clinical picture was indistinguishable from that of a subarachnoid hemorrhage from an intracranial lesion. The diagnosis was established by angiography and water-soluble contrast myelography followed by cervical computed tomographic scan. At surgery, the tumor was completely removed, and no neurological deficit was observed after the operation.

Adult↗