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Biomedical subjects

M Velasco

Publications and source records attributed to M Velasco.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Microscopic colitis and collagenous colitis. An entity not yet reported in Chile].

Collagenous and microscopic colitis have been described as causes for abundant watery diarrhea with a normal radiologic and endoscopic aspect of the colonic mucosa. Microscopic colitis is characterized by diffuse intraepithelial lymphocytic infiltration and collagenous colitis by thickening of subepithelial collagen layer greater than 15 microns with or without inflammatory changes of the mucosa. Here are reported 5 patients with microscopic colitis and 4 with collagenous colitis. The mean age was 52 years (range 40 to 68) with an equal sex distribution. Diarrhea was of longstanding duration without weight loss, anemia or hypoalbuminemia. Occasionally the volume of diarrhea was over 1 L a day. One patient had steatorrhea that proved resistant to a gluten free diet. Endoscopic and radiologic findings were normal in every patient and the diagnosis was based on typical histology. Azulfidine therapy was successful in 7 patients and prednisone in another. Colonic biopsy should be performed in every patient with chronic diarrhea.

Adult↗
PubMed1992

[Significance of investigating viral DNA in serum from patients with hepatitis B].

The DNA-HBV was investigated in 109 serum samples from 75 patients with different forms of infection with the HB virus, using an RIA hybridization technique (Genostic-Abott). DNA-HBV was present in 12 of 18 cases of acute hepatitis, 1 of 3 patients with fulminant disease, 11 of 14 patients with chronic hepatitis and/or cirrhosis, 2 of 10 patients with hepatoma and 6 of 30 asymptomatic chronic carriers. Presence of DNA-HBV beyond 60 days in 7 patients with acute hepatitis established the chronic state. The highest levels were found in patients with chronic hepatitis or cirrhosis (mean 41 +/- 11 pg/ml) and the lowest in chronic carriers and patients with hepatoma. High levels of DNA-HBV denote persistent viral replication and would support antiviral treatment. Thus, investigation of DNA-HBV has diagnostic, prognostic and therapeutic implications in patients with Hepatitis B.

DNA, Viral↗
PubMed1991

A double-blind, parallel, comparative evaluation of amlodipine vs. captopril in the monotherapeutic treatment of mild and moderate essential hypertension.

A double-blind, parallel, comparative study of the antihypertensive efficacy and safety of once-daily oral doses of amlodipine (5-10 mg/day) vs. twice-daily oral doses of captopril (25-50 mg twice daily) in adult patients with mild or moderate essential hypertension (supine diastolic blood pressure of 95-115 mm Hg) was undertaken in two hospital centers. Interim analysis of data from 40 patients shows that amlodipine and captopril both significantly (p < 0.05) reduced blood pressure compared with baseline. Nineteen of 21 (90.5%) amlodipine-treated patients and 15 of 19 (78.9%) captopril-treated patients had their diastolic blood pressure "normalized" (< 90 mm Hg) with mean final doses of 8.2 and 76.7 mg/day, respectively. At the final visit, there were no statistically significant differences between the two treatment groups in either mean supine or standing blood pressure. Minor nonsignificant changes in standing heart rate were observed in both treatment groups. Seven of the 21 amlodipine-treated patients and 3 of the 19 captopril-treated patients reported adverse experiences. No patients in either treatment group discontinued due to adverse events; one patient in the amlodipine group required a dose reduction. These interim data indicate that the overall efficacy and safety profiles of these two drugs are comparable.

Adult↗
PubMed1991

Autologous adrenal medullary transplants in advanced Parkinson's disease with particular attention to the selective improvement in symptoms.

Ten patients with advanced Parkinson's disease, presenting with tremor, rigidity and akinesia had autologous adrenal medullary transplantation taken from the left adrenal gland to the head of the right caudate nucleus. Particular attention was taken to avoid prolonged exposure of the adrenal tissue before transplantation and to separate the medullary from the cortical adrenal tissues. Postoperative CT scans confirmed the correct position of the transplants. Differences between pre- and 1-year postoperative clinical conditions were statistically evaluated, with patients under medical (L-dopa) treatment and after the medication was temporarily discontinued. Performance of motor tasks was tested to differentiate slowness of movements imposed by excessive muscular tension (rigidity) from that secondary to delayed reaction time to sensory demands (akinesia). Two deaths occurred 35 and 69 day after surgery for causes not related to the surgical procedures. One of those patients had remained stable neurologically and the other had deteriorated to progressive dementia and catatonia. At autopsy, no lesions in the CNS other than those expected from the surgical procedure were evident, and histological examination failed to reveal chromaffin cells in the head of the right caudate nucleus. Evaluation of the 8 cases that survived for 1 year revealed no significant improvement in their clinical or motor task performance, when considered as a group. However, cases with mild akinesia did better than cases with moderate to advanced akinesia, suggesting that transplantation is indicated in cases with rigidity, but not in cases with 'negative' symptoms of Parkinson's disease. All cases required postoperative medication.

Adrenal Medulla↗
PubMed1991

[Prolonged treatment with acyclovir in recurrent genital herpes. Clinical, virological, and immunological response].

The effect of a prolonged course of oral acyclovir was evaluated in 55 pts with recurrent genital herpes (36 men and 19 women). The pts were voluntarily enrolled after an acute episode, with tissue culture viral isolation. All the pts received an initial course with 200 mg of acyclovir x 5 for 10 days. Then they were randomly assigned to two groups (double-blind), one received 400 mg t.d. for 6 months and the other placebo. Clinical, virological and immunological follow-up included: tissue culture viral isolation, HSV antibody detection, serum Igs levels, T and B cell count, T-cell subsets (OKT3, OKT4, OKT8), C3 and phagocytosis test. The drug was well tolerated with hardly any side effects. Recurrences diminished dramatically in acyclovir treated pts, in contrast with those receiving placebo who did not show modification in viral recurrences. The immunological study was normal in most pts and did not change significantly during the trial.

Acyclovir↗
PubMed1991

[Spontaneous bacterial peritonitis: a frequent and recurrent complication in cirrhotic patients with ascites].

One hundred and twenty consecutive patients with liver cirrhosis and ascites were prospectively studied in order to analyze the frequency, clinical and bacteriological features, recurrence, and prognosis of spontaneous bacterial peritonitis (SBP). Two variants of SBP were defined: culture positive SBP and culture negative neutrocytic ascites (CNNA). During a follow-up of 6 +/- 2 months, thirty three episodes in 23 patients were identified. Nineteen episodes had ascites positive cultures (58%). The total mortality rate associated with SBP was 39%. (47% for culture positive form and 29% for CNNA). Seven of 15 cirrhotics who had recovered from a first episode of SBP (46%) had 10 recurrences. Mortality associated with SBP recurrence was 50%. Six-month survival probability was 65% in patients with sterile ascites and 33% in SPB (p < 0.05). Impairment of liver function was present in 23 episodes (70%) but abdominal complaints occurred only in one/third and 4 (12%) were asymptomatic. E coli was the most frequent agent involved in culture positive SBP. We confirm that SBP is a frequent, recurrent and severe complication of ascites in cirrhotics. Episodes of SBP without abdominal symptoms or with a silent course are not infrequent. Then, SBP recognition requires ample use of diagnostic paracentesis.

Adult↗
PubMed1990

Differential response to aminergic stimuli and biological behavior of growth hormone secreting pituitary adenomas.

Growth hormone (GH) serum levels in response to the administration of aminergic drugs and thyroliberine (TRH) were determined in a group of 34 acromegalics. Administration of bromocriptine (10 mg single oral dose) was followed by a decrease in GH below 60% control values in 35% of the cases. Administration of diazepam (10 mg single oral dose) to those cases not responding to bromocriptine induced a decrease in GH in 58% of the cases and an increase in GH in 42%. Administration of cyproheptadine (24 mg/day for one month) to those cases not responding to bromocriptine or with increased GH after the administration of diazepam, decreased GH in 75%, while increased GH in 25% of the cases. TRH 200 micrograms single I.V. dose induced increase of 128% GH basal level in 65% of cases (TRH positive) which correlated with more benign clinical course, decreased GH levels in response to bromocriptine, increased PRL levels, PRL-GH mixed secreting adenomas in immunohistochemistry studies, presence of granulated cells in electron microscopy studies and normalization of GH in the majority of surgically treated cases. By contrast, TRH negative cells correlated with aggressive tumor growth, lack of response to bromocriptine, normal PRL levels, pure GH secreting adenomas by immunohistochemistry, poorly granulated cells and lack of response to surgical treatment. Results suggest that there is more than one type of acromegaly that might be distinguished by the aminergic control on GH secretion.

Acromegaly↗
PubMed1990

Wakefulness-sleep modulation of EEG-EMG epileptiform activities: a quantitative study on a child with intractable epilepsia partialis continua.

Continuous all night recordings of epileptiform EEG activities from right frontal scalp and thalamic Centromedian regions and EMG activities from left deltoid muscular region were performed on a child with intractable epilepsia partialis continua, with depth stimulating-recording electrodes used for neuroaugmentive seizure control. In addition, "normal" and "mature" sleep indicators in the same child were simultaneously recorded according to the International Procedures. During wakefulness (W), type B seizures consisted of isolated, high amplitude, negative-positive EEG sharp waves recorded from the right Centromedian region (RCM sharp) correlated with isolated bursts of high amplitude EMG potentials recorded from the left deltoid muscle (LEMG jerks). Type C seizures consisted of clusters of repetitive RCM sharp and LEMG jerks, where individual EEG-EMG activities showed poor correlations. Number and amplitude of type B RCM sharp and LEMG jerks significantly decreased when patient directly shifted from W to slow wave sleep I and II (SWSI and II). Number and amplitude of RCM sharp increased while those of LEMG jerks decreased directly from SWS I and II to slow wave sleep III (SWS III); all forms of EEG-EMG epileptiform type B activities significantly decreased directly or indirectly from W and SWS to paradoxical sleep (PS). Scalp EEG spikes from right frontal and central regions showed almost parallel changes to those of RCM sharp, except during SWS II, when amplitude increased in the former and decreased in the later. Occurrence of type C seizures only decreased during PS and duration decreased directly from SWS I to II and indirectly from SWS I to SWS II and PS; and from W to SWS II and III and PS.

Child, Preschool↗
PubMed1990

[Genital HPV infection, relation between vulvar and cervico-vaginal localization].

The Authors studied 37 women affected by vulvar condylomatosis. Thirty-four presented features of florid or microflorid condylomatosis, three were affected by flat condylomatosis, Papillomavirus (HPV) infection of the cervico-vaginal tract was present in 25 women. No vulvar cellular atypia was found in the 37 cases with HPV lesions, while in 6 cases there were also cervical dysplasia (CIN 1-CIN 2). Nineteen out of 23 patients with disseminated revealed a vaginal flogosis mostly by yeats, detected by microbiological examinations. The evidence of disseminated florid or microflorid lesions associated with the virus infection, both located at the cervico-vaginal tract, support the ipothesis of virus types with higher virulence, a greater ubiquitary trophysm and a greater oncogenic risk, as supported also by other Authors.

Condylomata Acuminata↗
PubMed1990

[Anti-hepatitis C viral antibodies in different pathological entities in Chile].

In order to determine the prevalence of anti-hepatitis C viral antibodies in Chile, we determined antibody titers in preserved serum from 91 subjects using an ELISA method. The number and percentage of patients with positive titers was as follows: hemophiliacs without evidence of liver disease 88% (n = 25); prostitutes 0% (n = 25); sporadic non A non B hepatitis 0% (n = 12); chronic non alcoholic hepatitis with negative anti-HbsAg and anti HBc 63% (n = 10); hepatomas with negative titers as indicated for the previous group 30% (n = 10); post transfusion non A non B hepatitis 66% (n = 3). These results suggest that transfusion of blood products may be the main etiologic factor for Hepatitis C in our population.

Chile↗
PubMed1990

[Acute hepatitis by virus B in Chile: clinical and developmental characteristics].

We report clinical characteristics and follow up in 31 patients with acute B-hepatitis. Twenty were male and the age ranged from 9 to 80 years (mean 38). The infecting mechanism was probably related to homosexuality in 11, parenteral contact in 4 (1 post transfusional), health care workers in 4, home contact in 3, promiscuity in 3 and unknown in 6. Of 24 patients followed for a mean of 2 years, 20 recovered completely (84%). Anti HBs appeared 2 to 17 months (mean 8.3) after disappearance of HBsAg. Two had fulminant hepatitis and died, 1 developed chronic active hepatitis and 1 with subfulminant disease died after 6.5 months. Thus, the known risk factors for B-Hepatitis are confirmed in this series.

Acute Disease↗
PubMed1990

[Paracentesis combined with albumin infusion in the treatment of tense ascites in cirrhotic patients].

We randomized 31 cirrhotic patients with tense ascites to a Group A receiving only diuretic therapy (spironolactone, furosemide, n = 14) or a Group B treated with paracentesis and intravenous albumin infusion (n = 17). Ascites was eliminated in 88% of patients in Group B compared to 57% of patients in Group A (p < 0.05). Complications developed in 4 patients in Group A and 2 patients in Group B. Paracentesis was associated to a mild and transient reduction in mean arterial pressure and a significant rise in urinary output. Duration of hospital stay was 5 +/- 3 days in Group B and 22 +/- 6 in Group A (p < 0.001). Survival and likelihood of readmission for ascites was similar in both groups. Our results suggest that paracentesis plus intravenous albumin infusion is a fast, safe and effective therapy for tense ascites in cirrhotic patients.

Albumins↗
PubMed1990

[A submucosal hematoma of the esophagus. A clinical case].

Spontaneous intramural hematoma of the esophagus (SIHE) is a rare condition usually affecting middle-aged or elderly women. It presents as acute substernal or epigastric pain, typically accompanied by dysphagia or hematemesis. SIHE is not usually associated with vomiting, and is therefore clearly distinguishable from hematogenic esophageal disorders, such as the Mallory Weiss lesion and the Boerhaave syndrome. The pathogenesis is in dispute. We present a case of SIHE without a discernible mucosal breach, suggesting a primary intramural bleed as the initiating event. Its diagnosis relies on the history and a barium swallow. Instrumentation can result in further damage to the esophagus. Treatment is conservative and results in resolution of the hematoma and return to normal swallowing. A favorable prognosis is the rule.

Aged↗
PubMed1990

[Primary biliary cirrhosis. The experience in 33 consecutive cases].

Primary biliary cirrhosis is a chronic, progressive and often fatal cholestatic liver disease. We report clinical characteristics and follow up in 33 consecutive patients studied at a single university hospital during the last 10 years. 31 were female (94%) and the mean age was 51 +/- 2 years. At diagnosis, itching was present in 26 cases (78%). Association with autoimmune mediated diseases was frequent. Liver function tests showed marked cholestasis (alkaline phosphatase levels of 439 +/- 58 IU/l, range 90-1335). High antimitochondrial antibody titers and elevation of IgM levels were shown in all cases. According to liver biopsy findings, the diagnosis of primary biliary cirrhosis was an early one during the prospective phase of the study and was made in 8 +/- 1.4% of liver biopsies performed during this period. After a follow up of 27 +/- 5 months, 10 patients have died (30%). Our experience suggests that primary biliary cirrhosis is not an uncommon cause of chronic liver diseases in Chile.

Adult↗