Schweizerische Rundschau fur Medizin Praxis = Revue suisse de medecine Praxis最新文献

Sleep apnea syndrome (SAS) consists of nocturnal snoring interrupted by obstructive apnea and of diurnal symptoms like hypersomnolence as a consequence of sleep fragmentation. Cardiovascular morbidity and mortality associated with this syndrome justify early detection and appropriate treatment. Polysomnography is still a frequently used method for early detection; however, several disadvantages like duration, discomfort and expense led to a search for alternatives. Since the beginning of the eighties, oximetry allows recording of nocturnal oxygen saturation of hemoglobin even at home. Nocturnal oximetry reveals O2-desaturation associated with apnea and thus permits often to diagnose or exclude SAS. Diagnosis of SAS is made when at least 20 desaturations per hour with an amplitude of at least 4% are recorded. On the other hand, normal nocturnal oximetry nearly excludes SAS. In those cases where nocturnal oximetry is not diagnostic, polysomnography remains the method of choice. Departing from published work, a model for SAS detection, based mainly on nocturnal oximetry, is proposed.

The assessment of an erectile dysfunction (ED) includes the history, a clinical examination and blood tests. There is some confusion about which basic hormonal tests are needed at the beginning of clinical evaluation. We feel that with the results from our patients we could help to answer this question. From 1 January 1990 until the December 31 1993 we evaluated 1134 patients for ED. Those who favoured a surgical correction of their ED were fully evaluated by nocturnal penile tumescence testing, penile arteriography, intracavernosal injection of vasoactive agents and dynamic pharmaco-cavernosometry. The results from these tests were correlated with luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and prolactin. 183 (16.1%) of our patients with a mean age of 45 +/- 14 were fully evaluated. From these patients 76 were excluded because their ED was posttraumatic, undoubtedly psychogenic or could not be proven by the tests mentioned above. From the 107 patients finally included in this study, 90 had normal endocrine parameters. 17 patients had low testosterone. 14 of these patients had otherwise completely normal hormonal tests without evidence of secondary hypogonadism. Three patients had their low testosterone levels confirmed by repeated measurements. In addition, prolactin was significantly increased, and FSH and LH were near or below the lower reference value. When evaluating patients for the first time because of an erectile dysfunction, the measurement of testosterone as a single endocrine test is adequate. If testosterone is low, repeated measurements, combined with LH, FSH and prolactin, will identify patients with an ED due to an endocrine disease.

Clinically, acute hepatitis C is an asymptomatic disease in up to 90% of cases. Transaminases fluctuate characteristically. Anti-HCV (RIBA-II) and HCV-RNA (PCR) are diagnostic early in the course of the disease. The risk of chronification is high, exceeding 50% of cases, irrespective of disease transmission (parenterally or sporadic). Alpha-interferon is applicated in pilot-studies to reduce the risk of chronification, with varying results. Chronic hepatitis C is an insidious disease. Again, most cases are asymptomatic. Bilirubin is normal. GPT-activity tends to fluctuate during the course. Anti-HCV and HCV-RNA can be detected in serum. About 20% of cases progress to cirrhosis (and HCC) after a long-lasting disease (20 to 30 years after infection). Alpha-Interferon therapy is successful in about 25% of patients.

Hepatitis E virus (HEV) is a newly identified and molecularly characterized RNA virus. HEV has a worldwide distribution. Large epidemics were observed on the Indian subcontinent, in Central and in Southeast Asia. The enterically transmitted HEV infection also occurs in sporadic form. Only few cases of HEV infection with clinically apparent hepatitis were diagnosed in Western Europe and in the USA. HEV infection causes symptoms of a self-limiting, acute, icteric disease similar to those of hepatitis A. Severe and fulminant courses occur more often than with HAV infection. Chronic liver disease or persistent viremia have not been observed. Diagnosis of HEV infection is based on the detection of anti-HEV-antibodies.

Since the discovery of hepatitis C virus five years ago eight complete isolates and a large number of partial isolates have been sequenced. By comparing sequences, six HCV types can be differentiated which show more than 35% divergency in the NS5 proteins. The course of hepatitis C and the response rate after interferon therapy may be dependent on the HCV type. Serological tests for the diagnosis of acute and chronic hepatitis C have been improved, so that more than 90% of patients seroconvert at the peak of transaminases during acute infection; however in single cases, seroconversion can last up to nine months after onset of disease. Antibodies which can be detected in the acute and chronic phase of hepatitis C are directed against structural and nonstructural proteins. Most recently, also antibodies enveloping proteins E1 and E2 have been identified. These antibodies obviously do not seem to neutralize the virus. In patients with acute hepatitis C and complete recovery antibodies may persist up to ten years after onset of disease. At present there is no marker for past infection or immunity to HCV. Chronicity of hepatitis C and infectivity of patients can only be shown by detection of viral RNA using RT-PCR. Indications to perform PCR are patients prior to and after interferon therapy, hemodialysis patients, patients undergoing immunosuppression, new-born babies of mothers with chronic hepatitis C and patients with acute hepatitis C who are negative for antibodies.

Hepatitis B virus (HBV) mutants and hepatitis C virus (HCV) genotypes have recently been identified in patients with acute and chronic infections. Mutations may be associated with a specific clinical course of infection, e.g. chronic active or fulminant-hepatitis as well as the development of hepatocellular carcinoma (HCC). Further, mutations may affect clearance of HBV or HCV infection and the response to antiviral therapy with alpha-interferon; however, the exact contribution of specific mutations organotypes to the course of HBV or HCV infection remains to be established.

Elevated liver enzymes are a frequent clinical problem of varying significance. In otherwise healthy individuals the most frequent causes of elevated liver enzymes are toxins such as alcohol and drugs. In this situation, further studies are usually not needed; it is sufficient to control the relevant parameters after abstinence from alcohol or withdrawal of the drug(s). In patients with known, suspected or unknown nonhepatic diseases, elevated liver enzymes can be caused by cardiovascular diseases, obesity, endocrinopathies, infectious diseases, malignancies, collagen disorders, sarcoidosis and other diseases. In this situation, sonography or liver histology frequently will be diagnostic, revealing the cause of the underlying disease as well as of the elevated liver enzymes.

In carefully selected patients with viral hepatitis B, C (and D?), alpha-interferon (IFN) treatment is associated with a reduction of active viral replication. In chronic hepatitis B, HBeAg clearance rates approximate 40%. About 25% of patients with chronic hepatitis C will profit from a long-lasting (six to twelve months) IFN therapy. Treatment of chronic hepatitis D remains unsatisfactory, since only a minority of patients (less than 10%) finally will clear the virus, even if IFN is administered for one year. Due to the lack of data, IFN therapy cannot be recommended in the moment for patients at special risks, e.g. in the post-transplant situation, during immunosuppressive or hemodialysis therapy.