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Biomedical subjects

V Valdivieso

Publications and source records attributed to V Valdivieso.

At least 19 recordsLinked to original sources
PubMed1997

[Evidence-based medicine].

The need to improve the quality of health care and to contain its costs has become mandatory. Simultaneously we are confronted by a growing body of clinical information, most of it irrelevant. This paper describes the origin and methods of Evidence-Based Medicine, a new alternative to the usual ways of medical information. The recent development of computerized data bases is permitting the rapid location of relevant clinical information concerning specific questions on diagnosis, therapy or prognosis. Critical analysis is then used to determine the validity of the evidence obtained, which can be employed in clinical decision making. The future role of Evidence-Based Medicine in education and clinical practice seems highly promissory.

Evidence-Based Medicine↗
PubMed1996

[Study of volume and kinetics of gallbladder emptying in non-pregnant, pregnant, and puerperal women].

Gallbladder stasis apparently plays an important role in the patho-genesis of cholelithiasis during pregnancy. On the other hand, gallstones diagnosed immediately after delivery disappear spontaneously during late puerperium in one third of these patients. Gallbladder emptying was assessed by biliary scintigraphy and ultrasonography in normal, nulliparous volunteers. The two methods had an excellent correlation: thence, we used ultrasonography to determine gallbladder volume and contraction in pregnant and puerperal women. Fasting and postprandial residual volumes were significantly larger during pregnancy, while the kinetics f gallbladder emptying was similar in nulliparous and pregnant women. During puerperium, gallbladder volume returned to the values observed in nulliparae; but the kinetics of emptying was significantly faster, suggesting an increased sensitivity of gallbladder muscle to physiologic stimuli.

Adolescent↗
PubMed1995

[The internist, today].

The crisis of Internal Medicine is universal, and its fragmentation in an increasing number of sub-specialties is still taking place, with the undesirable results of dehumanization, excessive technification and increasing costs. Recent data indicate the growing and worrisome shortage of general internists in our country. The Medical disadvantages of the predominant care by sub-specialists are analized. The main features of the modern general internist are described. Changes in medical education and health policies to increase their number and professional quality are suggested.

Chile↗
PubMed1994

[Ideas contributing to the reform of the health sector in Chile].

General criteria are proposed for the organization of chilean health system. The fundamental ideas emphasize administrative decentralization, an effective and expedite intercommunication between different attention levels and a rationalization of the use of diagnostic procedures and treatments. The "basic health plan" features are outlined. The need for patient and family education and the access to tertiary medicine only through referrals is highlighted. The second part of article proposes changes in Medical Education. The need to reorient undergraduate medical formation towards solving outpatient problems and to extend specialization possibilities to all graduates, including Adult and Children general medicine training programs, is emphasized. The incorporation of basic economical concepts to the curriculum and group work training is considered beneficial. Finally, self-teaching behaviors and resolutive capacities in legal and ethical aspects should be encouraged in students. The potential teaching roles of future health reference, diagnostic and therapeutic centers is insinuated.

Adolescent↗
PubMed1993

Metaplasia and precursor lesions of gallbladder carcinoma. Frequency, distribution, and probability of detection in routine histologic samples.

BACKGROUND: Gallbladder diseases, especially cholelithiasis, are extremely frequent in Chile, and an increasing frequency of gallbladder carcinoma has been observed during the last decades. Hyperplastic and atypical epithelial lesions of gallbladder epithelium have been considered potential precursors of invasive carcinoma. The current study was designed to study the frequency, distribution, extension, and probability of routine detection of potentially preneoplastic changes of gallbladder epithelium. METHODS: Epithelial changes were histologically studied by mapping gallbladders obtained at elective cholecystectomy for lithiasis in 162 Chilean patients. RESULTS: Antral-type metaplasia was found in 95.1% of the cases, intestinal metaplasia in 58.1%, hyperplasia in 46.9%, dysplasia in 16%, and carcinoma in situ in 2.5%. A significant association of intestinal metaplasia with hyperplasia, intestinal metaplasia with dysplasia, and hyperplasia with dysplasia was found. Hyperplasia and dysplasia were also present in four cases with carcinoma in situ. Mean extension of the lesions (percentages of the sections in which the change was observed) was antral-type metaplasia (62.7%), intestinal metaplasia (25.3%), hyperplasia (24.1%), dysplasia (15.5%), and carcinoma in situ (9.7%). Antral-type and intestinal metaplasia were more extensive and more severe in patients older than 50 years of age. Hyperplasia was more extensive in cases in which it was associated with dysplasia and carcinoma in situ. CONCLUSIONS: The extension of metaplasia seems to depend in part on the age of the patients. The association of intestinal metaplasia with hyperplasia and dysplasia agrees with the findings of other authors that relate metaplasia to gallbladder cancer. The epithelial lesions are focal or partially confluent, thus a single random histologic section will detect less than one third of the hyperplasias, dysplasias, and carcinomas in situ.

Adult↗
PubMed1993

Pregnancy and cholelithiasis: pathogenesis and natural course of gallstones diagnosed in early puerperium.

Several recent reports have indicated an increased prevalence of gallstones in association with pregnancy. If these reports are true, the early puerperium should be a favorable time to detect the disease in its initial stages and follow its natural course. Accordingly, the gallbladder was examined by ultrasound in 980 women during the immediate postpartum period and in 150 nulliparous, age-matched healthy volunteers. Gallstones were detected in 12.2% of the puerperal women and in 1.3% of the control group. In 70 patients who had stones in a functioning gallbladder, 22 (31%) had had attacks of biliary colic. The history of pain was more common in patients with stones greater than 10 mm in diameter. Forty-one women with small stones (< 10 mm) were followed clinically and ultrasonographically for between 6 and 24 (mean = 8.7) mo. All remained pain-free, and in twelve subjects (29%) the stones disappeared. Gallbladder bile was examined in 11 normal volunteers (controls) immediately after delivery and in 19 women with small stones 39 +/- 6 days postpartum. Bile was saturated with cholesterol in the controls and was unsaturated in patients with gallstones. We conclude that in our population pregnancy is a very important pathogenetic factor favoring gallstone formation. Attacks of biliary colic appear early and frequently in young Chilean women with this disease. Unexplained disappearance of small stones frequently occurs: in some cases it is likely to be the result of spontaneous dissolution because bile becomes unsaturated within a few weeks of delivery.

Abdominal Pain↗
PubMed1992

[Correlation between ultrasound and pathology of the gallbladder].

Ultrasound is a sensible and specific method for the diagnosis, study of natural course and follow up of medical treatment of gallstones. Thus it is important to specify the concordance between echographic and pathological findings of the gallbladder. Ninety one patients were subjected to an ultrasound gallbladder examination immediately before elective surgery and the excised organ was pathologically examined right after the operation. The number and size of stones, the diameters and wall thickness of the gallbladder and the presence of polyps and septa were compared with both methods. The correlation was fair for the number or size of the stones considered separately; however the correct diagnosis of both parameters was obtained in only a third of the cases. Diameters of the gallbladder were underestimated by ultrasound; wall thickness measurement showed a very good correlation with both methods. No correlation was found for polyps or septa. Although ultrasound is excellent for the diagnosis of gallstones, its precision, is insufficient to determine the exact number and size of the stones.

Cholelithiasis↗
PubMed1992

[Miliary tuberculosis as a complication of BCG immunotherapy in cancer of the bladder. Case report].

Intravesical administration of BCG may be used as an ancillary immunotherapy after endoscopic resection for cancer of the bladder. Local side effects are usually mild. Here is reported a patient who developed miliary tuberculosis after this form of therapy. Radiologic studies of the thorax and liver biopsy confirmed the diagnosis. The patient recovered after treatment with anti-tuberculosis drugs (TA-81 scheme). Epithelial trauma may be invoked as an alteration facilitating this complication. Although it develops infrequently, patients with bladder cancer treated with BCG must be monitored for this complication.

BCG Vaccine↗
PubMed1990

[Relations of the physician and his patients in today's medicine: background and perspectives].

In the last decades, demographic, economic and social changes along with the explosive development of scientific and technological aspects in medicine have modified public expectations in health care. The doctor-patient relation has been modified accordingly. Access of all patients to the most sophisticated medical care seems increasingly difficult and may be considered utopic. Thus, education of both medical students and general public must be urgently directed towards the primary and secondary prevention of most common diseases. The doctor-patient relation must be strengthened in the framework of a solid humanistic and scientific basis.

Humans↗
PubMed1989

[Biliary lipid secretion in men with cholelithiasis].

Supersaturation of bile is indispensable for the appearance of cholesterol gallstones; it can be due to hypersecretion of cholesterol or to hyposecretion of bile acids and phospholipids. In a previous study we demonstrated cholesterol hypersecretion in Chilean women with gallstones. To elucidate the secretory defect in male patients we studied two groups of young men with normal body weight and a functioning gallbladder: four individuals with cholesterol gallstones and six healthy volunteers. The bile acid pool size and the secretory rate of bile acids and phospholipids were similar in controls and gallstone patients. On the other hand, cholesterol output was higher in the gallstone group. This study confirms the importance of biliary cholesterol hypersecretion as a major factor in the pathogenesis of gallstone disease in Chile.

Adult↗
PubMed1988

Frequency of gallbladder cancer in Chile, a high-risk area.

We report an autopsy study of gallbladder cancer prevalence in Chile, where the risk of this disease is among the highest reported world-wide. In 14,768 autopsy protocols obtained from 3 university hospitals, 45% of women and 20% of men older than 20 years had gallstone disease (the major known risk factor for gallbladder cancer). The prevalence of gallbladder cancer in Chileans was compared to that found in a Swedish-Czechoslovakian autopsy study previously published. These countries were chosen because of their high frequency of gallstone disease. The comparison was performed by using logistic regression models adjusting for possible differences in the age-sex structure or the true incidence of gallstones in both populations. We found that the most important single risk factor for gallbladder cancer in Chile was gallstone disease, with an estimated effect on the logistic scale meaning that the cancer risk for subjects with gallstones is seven times higher than for those without the disease. Second in importance was the risk for sex, women being 2.8 times higher than for men. The estimated difference in the sex composition and the incidence of gallstones resulted in 17.9% higher odds of cancer in Chile than in Sweden and Czechoslovakia. However, this difference was not significant. This study suggests that the major etiologic factors of gallbladder cancer in Chileans, Swedes and Czechoslovakians are primarily related to gallstone disease.

Adult↗