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Biomedical subjects

A Guerra

Publications and source records attributed to A Guerra.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Cystinuria: description of a simple method of determination and our 5-year clinical experience].

Ion exchange chromatography is the best method for the determination of cysteine in urine, but it requires an expensive apparatus, specialized technicians and a long time. The major colorimetric procedure is the nitroprusside color reaction first described by Brand, but it involves the reaction with toxic cyanide reagent. Moreover commercial stick are not available. We have experienced a colorimetric procedure in which the sulfhydryl group of cystine reduces phosphotungstic acid to tungstic blue, which is determined photometrically. This procedure avoids the use of cyanide. We used this screening test during 5 years of ambulatory evaluation of nephrolithiasis and we found these results: urine cystine 191 controls: 87 +/- 57 mg/day, 870 stone oxalate and uric acid patients: 99 +/- 57 mg/day, 11 stone cystine patients: 479 +/- 379 mg/day (p 0.001). A close correlation was found in stone cystine patients between our data obtained in the same sample with ion exchange chromatography. We conclude that this inexpensive and simple method can be recommended as a screening test for cystinuria.

Adolescent↗
PubMed1990

[Esophageal motility disorders in cirrhotics treated by sclerosing the varices].

We performed esophageal manometry on 17 cirrhotic patients (group I) treated with repeated varicose sclerosis (VS) after the varices had been completely eradicated. We used 5% ethanolamine oleate with the free hand technique, administering intra-varix injections at the cardia level, never exceeding 25 cc per session. The first two sessions were spaced a week apart, and the consecutive ones were on a monthly basis. The mean number of VS sessions was 5.52. The esophageal motility study was carried out on the average 12.3 months after the last VS session, with a minimum of six and maximum of 17 months. As controls we used 16 cirrhotic patients with unsclerosed varices (group II) and 26 healthy subjects (group III). The mean age and patient distribution were similar, according to Pugh grading. The length of the lower esophageal sphincter (LES) and the amplitude of the propulsive waves in the middle esophagus were similar in all three groups. We found the LES pressure to be significantly reduced in group I (17.52 +/- 2.8 mmHg) in relation to group II (20.26 +/- 2.49 mmHg) (p less than 0.001) and group III (22.86 +/- 3.73 mmHg) (p less than 0.01). The group II patients showed significantly lower pressure levels than the group III ones (p less than 0.05). The amplitude of peristaltic waves in the distal esophagus was significantly less in group I (22.94 +/- 7.31 mmHg) than in group II (37.46 +/- 10.95 mmHg) (p less than 0.01) and group III (44.8 +/- 11 mmHg) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Isolation of a gene that down-regulates nitrate assimilation and influences another regulatory gene in the same system.

Glutamine is the preferred source of nitrogen of Neurospora crassa. In its presence and that of the gene product of MS5 (nmr-1), the fungus represses the assimilation of less preferred forms of nitrogen, such as nitrate. In the absence of glutamine and the presence of the product of gene nit-2, less preferred forms of nitrogen are assimilated as long as a specific pathway for their assimilation is induced. We report here the isolation, from a cosmid bank, of a gene that complements MS5 and can also complement nit-2. We speculate that this result suggests an interaction between the MS5 and nit-2 gene products and that this is important in the regulation of nitrate assimilation.

Cosmids↗
PubMed1988

Abnormal renal responses to calcium entry blockade in normotensive offspring of hypertensive parents.

In nine young normotensive subjects with no family history of hypertension and nine age-matched normotensive subjects with one parent with essential hypertension, effective renal plasma flow (p-aminohippuric acid clearance), glomerular filtration rate (inulin clearance), and excretion of sodium and exogenously administered lithium were measured for 90 minutes before and after administration of a single 20-mg oral dose of the calcium entry blocker nifedipine. Segmental tubular handling of fluid and sodium was estimated using lithium clearance as a marker of proximal tubular reabsorption. Nifedipine did not cause any change in subjects with no family history of hypertension, but in those with one hypertensive parent there was a marked increase in effective renal plasma flow (from 644 +/- 39 to 847 +/- 42 [SEM] ml/min x 1.73 m2; p less than 0.001) and a decrease in filtration fraction (from 17.6 +/- 1.0 to 12.6 +/- 0.4%; p less than 0.001), while the glomerular filtration rate was unchanged, thus suggesting a prevailing efferent vasodilation. Sodium excretion rate (p less than 0.02) and fractional sodium excretion (p less than 0.025) increased slightly but significantly in subjects with one hypertensive parent, but not in normotensive subjects with no family history of hypertension. Lithium clearance also rose (from 29.0 +/- 2.0 to 32.8 +/- 1.9 ml/min, p less than 0.001), and the derived value of fractional proximal reabsorption diminished (from 75.8 +/- 1.0 to 71.3 +/- 1.2%, p less than 0.001). Estimated distal delivery of sodium and absolute distal sodium reabsorption both increased significantly (p less than 0.005), while fractional distal sodium reabsorption was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Renal colic: behavior of urinary parameters in the assessment of lithogenic risk].

In patients with renal colic we studied lithogenic urinary risk factors before and after the stone passage. We showed abnormalities in water, electrolytes and other substances excretion due to retention and metabolic disorders. The effects more pronounced is on urinary sodium, calcium, magnesium and ammonium. Citrate behaviour suggests a transient intracellular acidosis.

Adult↗
PubMed1987

Neoadjuvant chemotherapy for osteosarcoma of the extremity.

Eighty-five patients with nonmetastatic, high-grade osteosarcoma of an extremity received intravenous methotrexate and intraarterial cisplatinum and then a definitive surgical resection. The preliminary results suggest that preoperative chemotherapy with a delayed surgical resection is as safe as immediate surgery. More patients are candidates for limb salvage after chemotherapy. The tumor response to the preoperative chemotherapy also has prognostic value. Reducing the postoperative chemotherapy can be dangerous. A high dose methotrexate may not be necessary.

Adolescent↗
PubMed1987

A controlled clinical study on the efficacy of benzydamine in the topical treatment of non-specific cervicitis and vaginitis.

The authors report the results achieved in a controlled clinical study carried out for evaluating the efficacy of some topical preparations in the treatment of the so-called non-specific cervicovaginitis. The best results have been observed in 55 patients treated with a 0.1% benzydamine solution, whose efficacy was found to be significantly greater than that of povidone-iodine vaginal suppositories or a 0.2% aluminium acetate solution that were used in an additional 45 patients suffering from non-specific vulvovaginitis and exocervicitis, according to a fully randomized experimental study protocol. The results obtained in the non-selected population of the present study confirm the usefulness of benzydamine vaginal douches in the therapy of non-specific inflammations involving the lower female genital apparatus.

Acetates↗
PubMed1986

Adriamycin-methotrexate high dose versus adriamycin-methotrexate moderate dose as adjuvant chemotherapy for osteosarcoma of the extremities: a randomized study.

Adjuvant chemotherapy comprising Adriamycin (ADM) and Methotrexate (MTX) with Citrovorum Factor (CF) was administered on a randomization basis to 2 groups of patients with osteosarcoma after surgical ablation of the primary tumor. One group received high dose MTX (regimen I) and the other moderate dose MTX (regimen II). In both groups a short period of heparin treatment was also administered to prevent neoplastic emboli during surgery. All patients were free of metastasis at the beginning of therapy. The efficacy of therapy was determined by recording the percentage of continuously disease-free patients. This was compared to the disease-free survival in 132 patients previously treated with other ADM or ADM-MTX regimens and to a group of 39 patients treated during this period with amputation only. The latter did not receive adjuvant chemotherapy for a variety of reasons and are equated to a concurrent control group. Over the ensuing 27-66 months, 31 of 56 patients (55%) treated with regimen I and 25 of 50 (50%) treated with regimen II were disease-free. The overall disease-free survival in both regimens was 53%. This is similar to the 132 patients treated with previous adjuvant chemotherapy protocols (45-50%). However, the percentage of continuously disease-free patients treated with adjuvant chemotherapy was significantly better than the 39 patients (12%) treated contemporaneously with surgery only (P less than 0.0005). Survival in the latter is similar to that of historical control patients. These results do not suggest any change in the natural history of osteosarcoma and reveal benefits which may accrue with adjuvant chemotherapy. These results also demonstrate that in adjuvant treatment of osteosarcoma performed with ADM and MTX the high and the moderate doses of MTX are equally efficacious.

Adult↗
PubMed1986

Histologic study of the inhibition of bone resorption in organ cultures by myo-inositol-2-monophosphate.

This study examines chemically and histologically the relative abilities of inositol monophosphate (IP1), inorganic phosphate (Pi), ethane-1-hydroxy-1, 1-diphosphonate (EHDP) and dichloromethylene disphosphonate (Cl2MDP) to inhibit parathyroid hormone (PTH)--induced resorption of fetal rat long bones in organ culture. Pregnant rats injected with 45Ca on the 18th day of gestation were killed the next day and their fetuses removed. Half of each pair of dissected long bones was incubated in a chemically defined control medium while the contralateral half was incubated in medium containing PTH or PTH plus the compound to be tested. 45Ca released into the medium was indicative of the amount of bone resorption. Bones were then processed histologically and examined microscopically. All compounds inhibited resorption to some extent with IP1 and Pi being less effective than EHDP or C12MDP at comparable phosphate concentrations. However, the disphosphonates damaged osteoclasts whereas IP1 and Pi did not. This suggests that IP1 may inhibit resorption by a different mechanism perhaps related only to prevention of crystal dissolution.

Animals↗
PubMed1986

Thymomodulin in management of food allergy in children.

We studied 44 children, 7 months to 14 years old (15 males and 29 females), diagnosed for food allergy from the symptomatology, anamnestic data information, physical examination, determination of IgG/IgA/IgE plasmatic levels, and the application of the Prick test and RAST. The anamnestic data revealed a high prevalence of cow's milk feeding during the first 6 months of life, and a high incidence of allergies in the family, the mother being the most frequently affected relative. The children had a low IgA plasmatic level (56.78 +/- 6.3 mg%) and a high IgE plasmatic level (389 +/- 35 U/ml). RAST proved to be positive only in 28% of the subjects; the Prick test showed a better correlation with the symptomatology. The children were divided into groups A and B and submitted to an exclusion diet for 6 months, group B receiving oral Thymomodulin. At the end of this treatment period, a better food tolerance was achieved in the group of children treated with Thymomodulin combined with the exclusion diet. The oral challenge which induced a relapse of clinical symptomatology in 68% of the subjects in group A, induced it in only 29% of the subjects in group B. Furthermore, clinical manifestations were less severe in group B. In the group B children, the IgE plasmatic level showed a significant decrease (228 +/- 6 U/ml) (p less than 0.005), and the IgA plasmatic level rose to 98.35 +/- 8 mg% (p less than 0.01). No modifications were observed in the other immunological parameters studied. It is concluded that oral Thymomodulin combined with an exclusion diet was very effective in preventing food allergy relapses.

Adolescent↗
PubMed1985

Histologic evaluation of necrosis in osteosarcoma induced by chemotherapy. Regional mapping of viable and nonviable tumor.

The predominant sites of viable and nonviable tumor were determined in the primary lesions of 50 patients with osteosarcoma after initial treatment with preoperative chemotherapy. The degree of tumor destruction was classified as good, fair, and poor and a map of the sites revealing viable and nonviable tumor was constructed. The study revealed several preferential sites where viable tumor was likely to persist: soft tissues, cortex, subcortex, ligaments, and areas in contact with cartilage (growth plate and/or articular cartilage). Localized areas of hemorrhage and necrosis, designated "lacunae," were noted within the tumor. They were frequently surrounded by bundles of viable tumor and appeared to correlate with open surgical biopsies. Factors responsible for this phenomenon and the persistence of viable tumor are discussed. The findings have important implications in the design of surgical treatment and in the use of needle biopsies to determine the effects of preoperative treatment.

Adolescent↗