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Biomedical subjects

M A Calvo

Publications and source records attributed to M A Calvo.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Infectious external otitis: etiology in the Terrassa region, culture methods, and considerations on otomycosis].

The etiology of infections of the outer ear was studied in the area of Terrassa (Barcelona) over a six-year period (1987-1992). A total of 1419 samples of ear discharge were processed. Traditional culture media were used to isolate the microorganisms as well as a modified culture medium prepared by us (APA). Usual methods were used to identify the microorganisms. The results show Pseudomonas aeruginosa to be the most frequently isolated microorganism. 76.5% of the otitis studied were unimicrobial and the presence of moulds or yeast was noted in 6.9% of samples. Otomycosis (5.9%) is one of the major pathological processes of the outer ear, and Aspergillus niger is the prime causal agent.

Aspergillosis↗
PubMed1994

[Anatomopathologic changes in the testis following prolonged treatment with LHRH agonists. Experimental study in rats].

Presentation of a study conducted on 20 male Wistar rats treated for 3 months with Leuprolide (LHRH agonist). Analysis of pathophysiological testicular changes resulting from the treatment and extent of recovery at 3 months of therapy discontinuation, relating those changes to testosterone plasma levels in peripheral blood. Serum testosterone fell to 1.17 +/- 0.30 ng/ml in the treated group, shifting to figures overlapping with normal values within 3 months of discontinuing treatment. Such decreased testosterone levels translate into significant testicular histological damage. Three months after interruption of treatment there is nearly complete recovery of such damage, with just around 10% tubules without spermatozoa, with unchanged germinal line. We conclude that the marked suppression in testosterone levels caused by LHRH agonists translates into a significant degeneration of the seminiferous tubule, which appears to be reversible 3 months after treatment discontinuation.

Animals↗
PubMed1993

Effects of Ca2+ channel antagonists in guinea-pig normal and skinned gall bladder.

CaCl2 (0.01-50 mM, in K(+)-depolarized tissues), KCl (0.1-100 mM) and acetylcholine (1 nM-10 mM) produced concentration-dependent contractions of guinea-pig isolated gall bladder. Nifedipine (1-100 microM), verapamil (1-100 microM), diltiazem (1-100 microM), cinnarizine (1-100 microM), and flunarizine (1-100 microM) each produced a concentration-related inhibition of the log concentration-effect curve for CaCl2. The rank order of potencies of these antagonists, measured as the IC50 against Ca2+ (50 mM)-induced contraction of depolarized gall bladder, was diltiazem (0.25 microM) > or = verapamil (0.8 microM) approximately nifedipine (1.2 microM) >> cinnarizine (25 microM) approximately flunarizine (80 microM). Verapamil and diltiazem depressed KCl-induced contraction with an effectiveness and potency similar to those displayed against CaCl2 but nifedipine, cinnarizine and flunarizine were less effective against contractions in response to KCl compared to CaCl2. Verapamil and diltiazem, but not the other Ca2+ channel antagonists tested, had a specific inhibitory effect on the contractions due to KCl when compared to acetylcholine-induced contractions. Cinnarizine (10-100 microM) and flunarizine (10-100 microM), but not the other antagonists tested, depressed Ca2+ (20 microM)-evoked contraction of skinned guinea-pig gall bladder preparations. It is concluded that distinct differences exist between the Ca2+ channel antagonists examined. The action of nifedipine, verapamil and diltiazem is restricted to the plasmalemma whereas cinnarizine and flunarizine also act on the intracellular contractile apparatus.

Acetylcholine↗
PubMed1993

[Diagnostic value of aspiration cytology with ERCP].

ERCP is of great value in diagnosing malignant pathology of the biliopancreatic duct system. However, the ERCP endoscopic characteristics in malignant stenosis often lack specificity and are difficult to differentiate from those of chronic pancreatitis. In these cases histological confirmation is essential to diagnosis. With the aim of increasing the diagnostic possibilities of ERCP in pancreatic cancer--particularly when associated with chronic pancreatitis--we performed aspiration cytology of pancreatic juice obtained via endoscopic cannulation of the main pancreatic duct using ERCP in 102 patients with suspected periampullar pathology, chronic pancreatitis and/or pancreatic cancer. The diagnostic sensitivity of cytology for pancreatic malignancy was 33.3%, versus 60% for cancer of Vater's papilla. Specificity was 100% in both cancers. We observed no false positive results or complications. On combining both techniques, i.e., ERCP and cytology of the pancreatic juice, sensitivity increased to 100% for pancreatic malignancy, 77.7% for chronic pancreatitis (characteristic ERCP radiographic images and absence of neoplastic cells) and 100% in the case of ampullomas. Difficulties in the differential diagnosis between advanced chronic pancreatitis and pancreatic cancer persist with ERCP alone. In such cases aspiration cytology may secure a definitive diagnosis--particularly when neoplastic cells are demonstrated (Class IV).

Adult↗
PubMed1993

[Role of testosterone in the testicular microcirculatory changes produced in the rat by the administration of high doses of human chorionic gonadotrophin].

A study was performed in 20 male Wistar rats weighing 250-300 gm; 10 comprised the control group and the other 10 were treated with 5 mg/day of cyproterone acetate which was given with the meal for 2 months. The rat testicular microcirculation was studied by laser Doppler flowmetry. Similarly, the testicular interstitial fluid volume and plasma testosterone in peripheral blood were determined. Within each of the two groups, 5 were studied without any pharmacologic stimulation and 5 at 4 hours following the administration of 100 IU subcutaneous HCG. The rats treated with cyproterone acetate had very low levels of serum testosterone (1.254 +/- 0.667) versus the control group (3.686 +/- 0.705), the difference being statistically significant (p < 0.05). Following administration of HCG, the microcirculation changes and the interstitial fluid were the same as those of the control group despite the blockade of the androgenic receptors by cyproterone acetate. The increase in testosterone levels therefore does not appear to mediate the testicular microcirculation changes produced by HCG.

Androgen Receptor Antagonists↗
PubMed1993

[Testicular microcirculation in rats measured with laser-Doppler flowmetry].

Study carried out in 50 male Wistar rats distributed into 5 groups: baseline and at 2, 4, 8 and 24 hours after subcutaneous injection of Human Chorionic Gonadotropin, 100 IU. It was observed that testicular microcirculatory flow shows a rhythmical fluctuating pattern (5-10 fluctuations per minute), which becomes continuous at 4 hours but recovers at 24 hours. At the same time, there is an increased volume of testicular interstitial fluid that peaks at 8 hours, and returns to baseline levels at 24 hours. Serum testosterone values increase with HCG injection, reaching a peak at 4 hours (25.9 mg/ml), to return to nearly baseline levels at 24 hours (5.04 mg/ml). Disappearance of the rhythmical microcirculatory pattern, and the increase of interstitial fluid volume do not appear to be mediated by testosterone, since the raise in hormone levels, occurred after HCG administration, preceded the observed microcirculatory changes.

Animals↗
PubMed1992

Ultrastructure of the concentric membrane system in Arthrinium aureum.

An ultrastructural study was performed on Arthrinium aureum. The fungi were treated with glutaraldehyde and osmium tetroxide fixation. The hypha and conidia has a concentric membrane system which consisted of multiple membranes of a myelinoid appearance, and continued to the conidia and hypha plasma membrane. The fungi were also treated with periodic acid-alkaline bismuth (PABi) staining after glutaraldehyde and osmium tetroxide fixation. PABi positive materials were found on the marginal glycogen granules, the concentric membrane system and the conidia plasma membrane.

Microscopy, Electron↗
PubMed1992

Pathological lesions following an experimental intoxication with aflatoxin B1 in broiler chickens.

A follow-up of chickens dosed orally over 21 days with 0.2 and 3 micrograms of aflatoxin B1 (AFB1) g-1 of bodyweight daily and their subsequent recovery 10 days after withdrawal of contaminated food was conducted. Vacuolation of liver cells during the initial days of the intoxication and cellular depletion in the follicle medulla of the bursa of Fabricius were the lesions which appeared first and persisted during the recovery phase in both groups of intoxicated animals. The intensity of these lesions and their persistence was related to the dose of aflatoxin ingested. A significant reduction in the bodyweight and absolute weights of liver, bursa of Fabricius spleen and thyroid was observed in the higher dose group.

Aflatoxin B1↗
PubMed1992

Ultrastructure of the hyphae and conidia of Arthrinium aureum.

Electron microscopic observations of structures in Arthrinium aureum, which have not previously been described, are presented and discussed. Considerable attention is given to cytoplasmic inclusions, especially nuclei, mitochondria and Woronin bodies.

Cell Nucleus↗
PubMed1991

Xanthogranulomatous cholecystitis associated with gallbladder adenocarcinoma. A clinicopathological study of 5 cases.

The simultaneous presence of xanthogranulomatous cholecystitis and adenocarcinoma of the gallbladder has rarely been reported. A review of 53 cases of gallbladder adenocarcinoma in a 15-year period revealed 5 cases in which a concomitant diffuse xanthogranulomatous disease was observed. Clinical and pathologic features of these cases are commented and the diagnostic importance stressed. Both inflammatory and neoplastic components were closely mixed in 3 cases, thus making a prompt diagnosis difficult. Etiologic factors implicated in the development of both entities are considered.

Adenocarcinoma↗
PubMed1991

Gastric juice and analysis of basal and stimulated secretion following treatment with rice-bran oil.

In determining whether rice-bran oil (RBO) has antisecretory activity, we induced stress ulcers in 20 Wistar rats (10 controls; 10 animals given 0.2 ml/day RBO orally for 4 days prior to ulcer induction). In turn, we analyzed gastric juice for histamine, pepsin, H+ concentration ([H+]) and output volume. A second, complementary study was made of basal and stimulated gastric secretion through continuous "in vivo" recording of output. Secretion was stimulated with increasing doses of histamine, betanechol and pentagastrin. Ninety-four rats were used (47 controls and 47 rats given 0.2 ml/day RBO orally for 4 days prior to gastric output evaluation). The results were evaluated by the Student t-test. Ulcer index in the RBO-treated rats was significantly lower than among the controls (p less than 0.01), as also reflected by a significantly greater decrease in [H+] among the RBO-treated rats (p less than 0.05). However, no significant differences were observed for the remaining parameters. Continuous recording of basal gastric output showed a significant decrease in [H+] among the RBO-treated rats (p less than 0.01). Following histamine stimulation, [H+] was likewise significantly lower among the RBO-treated rats than in the controls. However, no significant differences were observed following stimulation with either betanechol or pentagastrin. RBO contains a high percentage of unsaturated fats; the latter act as precursors in the synthesis of arachidonic acid, which in turn is the essential precursor of prostaglandins--established inhibitors of gastric secretion. RBO also contains antioxidants such as alpha-tocopherol, which may likewise stimulate the synthesis of prostaglandins. RBO likely acts by increasing prostaglandin output, thus interfering with gastric HCl production.

Administration, Oral↗
PubMed1990

[Complicated hepatic hydatid cyst and acute pancreatitis. Value of ERCP and treatment with endoscopic sphincterotomy].

We present the case of a 29 year-old cholecystectomized woman with hepatic hydatid cysts who was admitted for acute pancreatitis. Echography and abdominal CAT revealed three thydatid cysts-the one in the right liver lobe being complicated-as well as pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) confirmed the suspected diagnosis of intrabiliary hydatid cyst rupture. An endoscopic sphincterotomy was performed, posterior evolution being asymptomatic, thus permitting the postponing of surgery.

Adult↗
PubMed1990

Influence of the addition of mineral salts on the inhibitory activity of strains of the Arthrinium genus.

The influence which the addition of certain mineral salts has on the inhibiting activity of strains belonging to the Arthrinium genus was studied. The salts employed were AgNO3, FeCl2, MnCl2 and CuSO4, in concentrations of 10, 50, 100, 150 and 200 mg/l, in the presence of Bacillus subtilis, Enterobacter cloacae, Staphylococcus aureus, Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Candida albicans and Aspergillus niger. For B. subtilis and S. aureus greater inhibition was observed after the addition of FeCl2 (200 mg/l) and MnCl2 (10 mg/l). E. coli showed a greater sensibility in the presence of AgNO3 (200 mg/l) and CuSO4 (150 mg/l). Inhibition before Enterobacter cloacae and Serratia marcescens was not increased by the addition of any of the salts. The addition of MnCl2 at 10 mg/l concentration to the basal medium showed a considerable increase of inhibitory activity over Klebsiella pneumoniae and Candida albicans. Activity for Aspergillus niger decreased when any of the salts were added to the medium.

Antibiosis↗
PubMed1990

[Treatment of gastroesophageal reflux by pexis to the round ligament. Report of 100 operated patients followed-up for 16 to 23 years].

In a study of 1,491 patients operated with ligament cardiopexy from 1,694 onwards, which we published in 1986, we reviewed 100 consecutive cases operated 15 years earlier or more. The review was based on a radioclinical (100), fiberscopic (53) and manometric (71) study, as well as on a measurement of the pH in doubtful cases (22). The results were distributed into categories A (normal), B (occasional disorders), C (functional disorders without recurrence) and R (recurrence), as follows: A + B 81%, C 12% and R 6%. This recent study confirms the conclusions we drew in 1981: a 15-minute operation that cures 94% of the patients without recurrence after 15 years and more is an appropriate procedure.

Female↗