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Biomedical subjects

F Diaz

Publications and source records attributed to F Diaz.

At least 55 records · Page 3Linked to original sources
PubMed1995

Pyruvate dehydrogenase complex from the primitive insect trypanosomatid, Crithidia fasciculata: dihydrolipoyl dehydrogenase-binding protein has multiple lipoyl domains.

The pyruvate dehydrogenase complex (PDC) has been purified to apparent homogeneity from the insect trypanosomatid, Crithidia fasciculata, a member of the most primitive eukaryotic group to contain mitochondria. Separation of the purified PDC by SDS-PAGE yielded five bands of 70 (p70), 60 (p60), 55, 46 and 36.5 kDa, which appeared to correspond to dihydrolipoyl dehydrogenase binding protein (E3BP), dihydrolipoyl transacetylase (E2), E3, E1 alpha and E1 beta, respectively. The purified complex did not exhibit endogenous PDHa kinase activity. p70 was much less abundant than p60. Polyclonal antisera raised against p70 did not cross-react with p60, and antisera raised against p60 did not cross-react with p70, suggesting that p60 did not arise from p70 by proteolysis. Both p70 and p60 contained similar amino terminal sequences. Both sequences contained the MPALSP motif similar to sequences present in both E3BP and E2 from other sources. Incubation of the purified PDC with [2-14C]pyruvate in the absence of CoA resulted in the acetylation of both p70 and p60, suggesting that both proteins contained lipoyl domains, but the specific incorporation of label into p70 was significantly greater than for p60. Limited proteolysis of the acetylated complex with trypsin yielded two major fragments derived from p60 of 35 and 30 kDa, corresponding to E2L and E2I, and one major acetylated fragment of 58 kDa derived from p70. Therefore, these results suggest that p70 is an E3BP and given its apparent M(r) and degree of acetylation, it contains multiple lipoyl domains.

Amino Acid Sequence↗
PubMed1995

Factors associated with Taenia solium cysticercosis: analysis of nine hundred forty-six Peruvian neurologic patients. Cysticercosis Working Group in Peru (CWG).

In most developing countries, 10% of acute neurologic cases are patients with neurocysticercosis (NCC). Determining specific factors associated with contracting NCC will facilitate its diagnosis and prevention. We examined multiple socioeconomic, demographic, environmental, medical, and behavioral characteristics of 946 Peruvian neurologic patients for a correlation with NCC, which was diagnosed by the highly specific and sensitive electroimmunotransfer blot (EITB) or immunoblot assay. Eighteen percent (172 of 932) of serum samples and 28% (101 of 362) of cerebrospinal fluid samples were EITB-positive. The proportion of EITB-positive persons was similar for all socioeconomic levels. Significant factors associated with NCC were: 1) being born outside Lima, 2) having raised pigs, 3) more than 20 years of age, 4) a history of seizures, and 5) a history of taeniasis. Of these factors, raising pigs is the only one that is amenable to intervention, via improvements in animal husbandry.

Adolescent↗
PubMed1995

Comparison of bladder management complication outcomes in female spinal cord injury patients.

A total of 70 female spinal cord injury patients was retrospectively analyzed for outcomes of long-term bladder management. Three groups were defined: 1) 23 patients on intermittent catheterization, 2) 25 treated by reflex voiding and incontinence padding, and 3) 22 with an indwelling catheter. Mean years of using the specific bladder management technique were 8.5 +/- 4.7, 15.8 +/- 7.3 and 16.7 +/- 9.0 for the 3 groups, respectively. All patients were evaluated for long-term complications. There were 4 major complications (17%) in the intermittent catheterization group, 10 (40%) in the padding group and 58 (greater than 200%) in the indwelling catheter group. The aggregate difference in complication rates among the 3 group was highly significant (p < 0.00001). Of comparable long-term patients (11 to 23 years) there were no major complications among 6 on intermittent catheterization, 8 among 14 who use padding and 21 among 9 with an indwelling catheter. The differences among the groups remained significant (p < 0.00001). Additional analyses showed highly significant differences between the catheter group and the other 2 groups (intermittent catheterization p = 0.0009 and padding p = 0.0005), and a difference that approached significance between the intermittent catheterization and padding groups (p = 0.085). The results strongly support intermittent catheterization as the optimal management of female patients following spinal cord injury given that other factors, in particular independent hand function or the need for appropriate assistance, are considered.

Catheters, Indwelling↗
PubMed1994

Pyruvate dehydrogenase complexes from the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum, helminths exhibiting anaerobic mitochondrial metabolism.

The pyruvate dehydrogenase complex (PDC) has been purified to apparent homogeneity from 2 parasitic helminths exhibiting anaerobic mitochondrial metabolism, the equine nematode, Parascaris equorum, and the canine cestode, Dipylidium caninum. The P. equorum PDC yielded 7 major bands when separated by SDS-PAGE. The bands of 72, 55-53.5, 41 and 36 kDa corresponded to E2, E3, E1 alpha and E1 beta, respectively. The complex also contained additional unidentified proteins of 43 and 45 kDa. Incubation of the complex with [2-14C]pyruvate resulted in the acetylation of only E2. These results suggest that the P. equorum PDC lacks protein X and exhibits an altered subunit composition, as has been described previously for the PDC of the related nematode, Ascaris suum. In contrast, the D. caninum PDC yielded only four major bands after SDS-PAGE of 59, 58, 39 and 34 kDa, which corresponded to E3, E2, E1 alpha and E1 beta, respectively. Incubation of the D. caninum complex with [2-14C]pyruvate resulted in the acetylation of E2 and a second protein which comigrated with E3, suggesting that the D. caninum complex contained protein X and had a subunit composition similar to PDCs from other eukaryotic organisms. Both helminth complexes appeared less sensitive to inhibition by elevated NADH/NAD+ ratios than complexes isolated from aerobic organisms, as would be predicted for PDCs from organisms exploiting microaerobic habitats. These results suggest that although these helminths have similar anaerobic mitochondrial pathways, they contain significantly different PDCs.

Acetylation↗
PubMed1994

Zamorano-Dujovny multipurpose neurosurgical image-guided localizing unit: experience in 866 consecutive cases of 'open stereotaxis'.

We describe the Zamorano-Dujovny localizing unit which consists of a ring-shaped headholder held on the patient's head by three or four variably placed fixation pins, thereby avoiding interference with the flap sites or craniotomy. The base ring is mounted intraoperatively on a special adapter that allows any patient positioning including supine, lateral prone, 3/4 prone, sitting, etc. Imaging studies, such as computed tomography, magnetic resonance imaging, x-ray, digital angiography, and digital subtraction angiography can be performed with the headholder anchored in place for multimodality image localization. Surgical draping can be done over the ring to provide a completely sterile field. An arc/quadrant localizing device can be mounted on any four alternative positions according to the neurosurgeon's preference. PC-compatible software gives the setting for any possible mounting. Intraoperatively the localizing unit can be used in a 'fixed' permanent setting or as a 'nonfixed' system to provide intraoperative three-dimensional orientation. Different types of instruments compatible with the unit extend its capabilities, such as 'bayonet'-type brain retractors (cylinders and speculum) that keeps the surgical corridor unobstructed from the arc. As an alternative, in the nonfixed setting, self-retaining arms are fixed to the base ring and brain retractors and conventional microsurgical techniques can be used without any mechanical obstruction.

Angiography, Digital Subtraction↗
PubMed1994

The epidemiology of Helicobacter pylori in Peruvian children between 6 and 30 months of age.

OBJECTIVES: Cross-sectional studies of children in developing countries show a high prevalence of Helicobacter pylori infection at 6 months of age, but a decrease in the prevalence of infection between 1 and 5 yr of age. The decrease suggests a loss or clearance of infection, an uncommon finding in adults. Our objective in this study was to determine the longitudinal persistence of H. pylori infection in young children. METHODS: We tested an initial cohort of 105 6-month-old infants at 6-month intervals with the 13C-urea breath test; 56 subjects were successfully studied for 2 yr or until 30 months of age. RESULTS: Overall prevalence decreased from 71.4% to 47.9% when children were between 6 and 18 months of age, and we found a significant gender difference (males 63.6-55.0%, females 80.0-38.7%, p = 0.03). Of the 56 subjects, six had negative breath tests at all 6-month intervals, 10 were consistently positive, and 36 subjects had one or more negative tests after a positive test. The overall probability of acquiring H. pylori in a given 6-month period ranged between 0.28 and 0.38; the probability of clearing the infection was between 0.22 and 0.45. During the first 18 months after birth, male infants were more likely to acquire H. pylori and less likely to clear the infection than female infants. CONCLUSION: We conclude that H. pylori colonization in infants may be a reversible process.

Breath Tests↗
PubMed1993

Cysticercosis as a major cause of epilepsy in Peru. The Cysticercosis Working Group in Peru (CWG)

In countries where cysticercosis is endemic, the proportion of epilepsy due to cysticercosis is not well documented. To investigate the association between cysticercosis and epilepsy, we used the enzyme-linked immunoelectrotransfer blot (EITB) assay to detect serum antibodies to Taenia solium in 498 consecutive outpatients at a neurology clinic in Lima, Peru. Every patient was classified as epileptic (n = 189) or non-epileptic (n = 309) after neurological, and where possible electroencephalographic, examination. A substantially higher proportion of epileptic than non-epileptic patients was seropositive in the EITB (22 [12%] vs 8 [3%], p < 0.001). 19% of epileptic patients born outside Lima, 20% of those with late-onset epilepsy, and 29% of patients with both these characteristics were seropositive. Thus, in Peru, cysticercosis is an important aetiological factor for epilepsy.

Adolescent↗
PubMed1993

Three syndrome concept of schizophrenia. A factor analytic study.

One hundred and fifty-five DSM-IIIR schizophrenic patients were assessed for positive and negative symptoms using Andreasen's Scale for Assessment of Positive Symptoms (SAPS) and the Scale for Assessment of Negative Symptoms (SANS). Interrelationships of individual positive and negative symptoms were examined using a factor analysis. Results of the factor analysis are consistent with Liddle's proposition that there are three syndromes underlying symptomatology in schizophrenia: disorganization; psychomotor poverty and reality distortion.

Adolescent↗
PubMed1993

Diagnosis of pleural tuberculosis by detection of specific IgG anti-antigen 60 in serum and pleural fluid.

The objective of this study was the prospective evaluation of the IgG antibody levels to mycobacterial antigen 60 (A60) in serum and pleural fluid and their role in the diagnosis of tuberculous pleuritis. The level of IgG was measured by Elisa in 30 patients with tuberculous pleuritis and 48 control subjects with pleural effusion (24 with carcinoma, 10 with transudative pleural effusion, 11 with empyema or parapneumonic effusion, 1 with pulmonary embolism and 2 due to systemic lupus erythematosus). The median titers of IgG against A60 of both serum and pleural fluid from tuberculous patients [445.6 +/- 133.56 and 263 +/- 72.58 Elisa units (EU) respectively] were significantly higher than those of corresponding median values (97.3 +/- 8.35 and 41.3 +/- 4.93 EU) of the control group (p < 0.01 and p < 0.01, respectively). Considering 240 units as cutoff point for a positive test in serum, the sensitivity was 53.3% and the specificity 100%. In the pleural fluid the cutoff point value was established at 150 units, with a sensitivity of 50% and specificity of 100%. We concluded that Elisa using A60 is a reliable and rapid test with an acceptable sensitivity and magnificent specificity.

Antibodies, Bacterial↗
PubMed1993

Water cost and availability: key determinants of family hygiene in a Peruvian shantytown.

OBJECTIVES: This study was conducted to determine whether poor hygiene practices are owing to difficulty in getting enough water and/or to ignorance of sanitary principles. METHODS: In a water-scarce shantytown in Lima, Peru, we observed in 12-hour periods over 3 consecutive days the amount of water and soap used for personal and domestic activities in 53 families and the frequency with which direct fecal contamination of hands was interrupted by washing. We also surveyed women in a similar shantytown concerning their knowledge of hygiene to ascertain whether noncompliance was owing to ignorance. RESULTS: Three hundred fecal contamination events were registered, of which only 38 (13%) were interrupted by hand washing within 15 minutes. The mean 12-hour per capita amount of water and soap used by the families was low. More than 80% of the water stored by these families had fecal coliforms. Yet the level of knowledge concerning the importance of hand washing and other hygienic practices was high. CONCLUSIONS: In water-scarce areas, sanitary education programs probably will not change hygiene practices. In these areas, an adequate supply of water is essential for good hygiene.

Adolescent↗
PubMed1993

Neonatal tetanus in Peru: risk assessment with modified enzyme-linked immunosorbent assay and toxoid skin test.

We used a modified enzyme-linked immunosorbent assay (ELISA) to investigate tetanus immunity in 232 pregnant Peruvian women. One hundred forty-two (61.2%) had protective antitoxin titers (> or = 0.01 IU/mL). Protective titers correlated positively with the number of toxoid doses reported during the current pregnancy. A majority of women reporting no toxoid doses during the current pregnancy had at least one prenatal health care visit. We evaluated a toxoid skin test in 44 of the subjects, but it correlated poorly with the ELISA. The modified ELISA is a useful in vitro method for studying tetanus immunity in the developing world.

Adult↗
PubMed1992

Epidemiology of taeniasis and cysticercosis in a Peruvian village. The Cysticercosis Working Group in Peru.

To determine the prevalence of cysticercosis in a rural area where the disease is endemic, the authors studied the seroepidemiology of human and porcine cysticercosis in a Peruvian jungle community (Maceda, Peru) in 1988 using an enzyme-linked immunoelectrotransfer blot (EITB) assay. Of the 371 sampled inhabitants, 30 (8%) were seropositive, most of whom were asymptomatic. After niclosamide therapy, four Taenia species worms were identified in the seropositive group, compared with one in the control group (p = 0.06). Pigs were frequently infected: 44 of 133 (33%) were found positive for Taenia by tongue examination and 57 of 133 (43%) were positive by EITB. In 69% of the sampled households that had pigs, there was at least one seropositive pig. The number of pigs diagnosed positive by the tongue examination was significantly greater in households that had latrines than in those that did not. Cysticercosis is a common but usually asymptomatic infection that affects both humans and pigs in the high jungle areas of Peru.

Adolescent↗
PubMed1992

[Postoperative acute aortic dissection. Apropos of two cases].

Aortic dissection after cardiac surgery is a rare complication. The prognosis is often poor: 33-78% of mortality. The study of two cases out of 2100 patients operated upon during the last three years, and the review of the literature, allows to recall the mechanism, the anatomic origin and the different surgical techniques. Early diagnosis is essential. Some preventive techniques may reduce the incidence of the iatrogenic dissections.

Aged↗
PubMed1992

[Technical problems during coronary revascularization in case of massive calcified aorta].

A massively calcified ascending aorta which may make aortic clamping impossible, is a major obstacle to coronary revascularisation surgery. The aim of this study was to demonstrate that by the use of certain technical modifications, these patients can be treated even in multivessel disease. In the author's experience, two patients with this condition underwent complete revascularisation with a good surgical result controlled by angiography. The sites of arterial cannulation were the aortic arch in one case, the brachiocephalic artery and the common femoral artery in the other case. The ascending aorta was not clamped in either patient or used as the origin of the coronary bypass grafts. Myocardial protection was performed by systemic cooling with ventricular fibrillation without cardioplegia. The feasibility of these methods has led to the suggestion of a classification of the aortic wall according to peroperative palpation. This classification would provide indications for the use of technical modifications not only in extreme cases of aortic calcification but also in patients with severe atherosclerotic changes at high neurological risk; it would not, however, interfere with the classical technique of revascularisation.

Aged↗