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Biomedical subjects

M Horn

Publications and source records attributed to M Horn.

At least 109 records · Page 6Linked to original sources
PubMed1994

Beta-blockers in cardiac failure.

The use of beta-blocking agents in patients with heart failure is still controversial. An activated sympatho-adrenal system in heart failure may support blood pressure and cardiac index, on the other hand, it increases cardiac load and myocardial oxygen consumption, reduces myocardial oxygen supply and may contribute to the high incidence of arrhythmias and sudden death. Today there is a certain awareness about the important role of the sympatho-adrenal system in CHF. Short-term studies failed to demonstrate a benefit of beta-blockers while long-term studies have proved major haemodynamic benefit and functional improvement in most patients. The haemodynamic benefit consists of a reduction of heart rate and left ventricular filling pressure and an improvement in exercise capacity. The mechanism of these actions of beta-blockers, with the exception of lowering heart rate, remains unclear. Energy metabolism of the failing heart, which is considered to be deficient, may beneficially be influenced by chronic beta-blocker treatment. Effects of beta-blockers on prognosis in patients with heart failure are also still controversial. Most recent trials (MDC Trial, CIBIS Trial) were inconclusive concerning mortality. Aetiology of heart failure may be important; however, observations on secondary prevention post-myocardial infarction also contradict heart failure studies. Thus, further efforts are urgently needed to define the mechanism of action of beta-blockers in patients with cardiac failure and to identify more clearly patients who benefit from this type of therapy.

Adrenergic beta-Antagonists↗
PubMed1994

Radical surgery (R2 resection) for gastric cancer. A multivariate analysis.

BACKGROUND: Extended lymphadenectomy remains controversial in the Western world. Its evaluation and the identification of high-risk patients after surgery are important tasks. METHODS: A retrospective prognostic study of 318 patients treated for potential cure of gastric cancer was performed. All patients underwent extended lymphadenectomy. Clinical histopathologic and surgical factors were examined for their influence on survival by univariate and multivariate analysis. RESULTS: Postoperative mortality was 4.4% (14 of 318), and the 5-year adjusted survival rate was 57.8%. Multivariate analysis using the Cox model identified seven factors as having independent influence on survival. Detrimental factors were male gender, age over 65 years, high pN category, increasing number of lymph nodes invaded by metastases, total gastric resection, splenectomy, and increasing number of perioperatively required blood units. CONCLUSION: Extended lymphadenectomy was possible without sacrificing low postoperative mortality rates. The importance of certain prognostic factors, in particular lymph node status, could be confirmed.

Aged↗
PubMed1994

[Burden of DDT, HCH, HCB and PCB in human milk in the former German Democratic Republic. Research and toxicologic evaluation].

The decreasing tendency of the contamination of human milk with residues of organochlorine compounds (DDT, HCH, HCB, PCB) has been confirmed by our investigations also for the territory of the former GDR. Compared with the residue-situation existing in the FRG, the contamination of breast milk with DDT-metabolites 4,4'-DDE and 4,4'-DDT were elevated. A positive correlation was found between age and HCB-exposure, urban residency and 4,4'-DDE, beta-HCH and PCB, and smoking and beta-HCH-residues in human milk.

Age Factors↗
PubMed1994

[Therapeutic hypothermia after cerebral ischemia. Theoretical principles and possible clinical applications].

In animal models of cerebral ischemia hypothermia has been shown to have a beneficial effect. Reduction of infarct size, fewer potentially neurotoxic metabolites, and a better neurological outcome were observed compared to sham-operated animals. In clinical practice hypothermia has been widely used in cardiovascular surgery and occasionally in neurosurgery. The first trials with hypothermia in patients with severe head injury have also shown beneficial results. However, studies on therapeutic hypothermia in the clinical management of acute stroke are not yet available.

Animals↗
PubMed1994

[Indications for ACE inhibitors in the postinfarct period].

Prognosis of patients post-myocardial infarction depends largely on the degree of left ventricular dysfunction, which results from loss of contractile tissue and remodeling of infarcted and surviving myocardium. This remodeling process may result in chronically progressive dysfunction and ultimately in heart failure. Next to mechanical determinants humoral control of hypertrophy, dilatation and qualitative changes of surviving myocardium are discussed. A major determinant of the extent of remodeling is infarct size. Efficacy of angiotensin-converting enzyme (ACE) inhibitors on infarct size was tested in animal experiments with conflicting results. Recent clinical studies also report beneficial (GISSI-3 and ISIS-4) or no (CONSENSUS II) effects on survival post-myocardial infarction when ACE-inhibitors were used in the acute phase. Up to date it remains unsettled which patients may benefit from acute therapy with ACE-inhibitors. Three days after myocardial infarction hemodynamically stable patients with heart failure may be treated with ACE-inhibitors (AIRE study). Prognosis may be improved and manifestation of heart failure prevented or delayed also in patients without heart failure treated in this phase of myocardial infarction with ACE-inhibitors (SAVE study). Prevention of heart failure may also be observed in patients treated later (at least 4 weeks) after myocardial infarction (SOLVD prevention arm). It is essential for this indication that patients are carefully selected for treatment depending on left ventricular function. Duration of treatment in patients with severe left ventricular dysfunction probably has to be lifelong, the doses of ACE-inhibitors used have to be relatively high (e.g. 3 x 50 mg captopril or 2 x 10 mg enalapril).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

[Abdominal wall implantation metastasis 2 years after apparently uneventful laparoscopic cholecystectomy].

An extraordinary rare case of implant metastasis at the laparoscopic working port, two years after an apparent uncomplicated laparoscopic cholecystectomy is presented. The histological reexamination of the gallbladder with the detection of a minimal carcinomatous lymphangiosis in newly prepared sections, the exclusion of other primary tumors and also the tumor-free interval of six months until now, after radical excision of the abdominal wall, are strongly suggestive for an intraoperative tumor cell dissemination into the abdominal wall by a histologically unrecognized carcinoma of the gallbladder.

Abdominal Muscles↗
PubMed1994

Debating NSI.

Explore the source record for details and available documents.

Adult↗
PubMed1994

[Surgical methods in the treatment of retroperitoneal neuroblastoma].

The authors submit their experience with the surgical treatment of retroperitoneal neuroblastoma, which is one of the most frequent solid tumours of child age. They describe the principles of the surgical technique with emphasis on radical removal of the tumour even in the area of large blood vessels. They emphasize the advantage of using an ultrasonic surgical aspirator (CUSA, Valleylab Co., Pfizer) which makes it possible to remove residues of the tumour without damaging the large blood vessels. During the period between 1987-1992 they treated at the Motol Faculty Hospital 69 children with retroperitoneal neuroblastoma. Of these 60 were operated. In the first stage of the disease 9 patients were operated, all survive. In the second stage 4 patients were operated, 75% survive, in the third stage 24 patients 50% survive, in the fourth stage 20 of 29 patients were operated and 11 (38%) survive. In stage IV--S three patients were operated, one survives. The total survival of patients during the investigation period is 52%.

Adolescent↗
PubMed1993

Hormonal regulation and properties of a new group of basic hemolymph proteins expressed during insect metamorphosis.

Two abundant basic proteins, and arylphorin, that are expressed during metamorphosis of Trichoplusia ni were isolated, their cDNAs cloned, and regulation of their expression assessed. According to the criteria of encoded protein sequence, positions of sequence coinitiation and cotermination, amino acid compositions, nonsex-specificity, and immunological analyses, the related yet distinct basic proteins do not correspond to any previously established group of insect proteins, each of which can be distinguished on the basis of such criteria, although they appear to be within the arthropod hemocyanin superfamily. The basic proteins can be separated under native isoelectric focusing conditions, indicating that they do not preferentially form heteromeric complexes under such conditions. While the transcripts for both basic proteins and a coexpressed acidic protein (Jones, G., Brown, N., Manczak, M., Hiremath, S., and Kafatos, F. (1990) J. Biol. Chem. 265, 8596-8602) appeared in both sexes on the day prior to ecdysteroid-driven metamorphic commitment, and persisted at high abundance for the next 24 h, the arylphorin mRNA appeared 1 day earlier and declined immediately after metamorphic commitment. The dynamics of suppression of the appearance and abundance of transcripts in response to maintenance of a high juvenile hormone titer was different for the acidic versus the two basic proteins. Another regulatory difference in response to juvenile hormone was shown by a decreased translatability of the mRNAs for the two basic proteins, but not for the acidic protein. In contrast, the abundance and translatability of arylphorin mRNA was insensitive to a high juvenile hormone level. A further difference in regulation was shown by the maintenance of a high level of both arylphorin and the acidic protein in the hemolymph after disappearance of their transcripts, while the basic proteins instead disappeared from the hemolymph and persisted in the fat body. These results establish at least three qualitatively different effects of juvenile hormone on the abundance of transcripts for these representatives of three groups in the hemocyanin superfamily, and also establish mRNA translatability as another differential level of regulation among them. Given these differences in mechanisms of regulation of evolutionarily related proteins, this system of metamorphosis-associated proteins in T. ni should prove to be a valuable tool in studies of mechanisms of hormonal regulation of gene expression during the metamorphic transformation of larval tissues.

Adipose Tissue↗
PubMed1993

Molecular analysis and genetic mapping of the rhodopsin gene in families with autosomal dominant retinitis pigmentosa.

Eighty-eight patients/families with autosomal dominant retinitis pigmentosa (RP) were screened for rhodopsin mutations. Direct sequencing revealed 13 different mutations in a total of 14 (i.e., 16%) unrelated patients. Five of these mutations (T4K, Q28H, R135G, F220C, and C222R) have not been reported so far. In addition, multipoint linkage analysis was performed on two large families with autosomal dominant RP due to rhodopsin mutations by using five DNA probes from 3q21-q24. No tight linkage was found between the rhodopsin locus (RHO) and D3S47 (theta max = 0.08). By six-point analysis, RHO was localized in the region between D3S21 and D3S47, with a maximum lod score of 13.447 directly at D3S20.

Australia↗
PubMed1993

Intrauterine tachycardia and periventricular leukomalacia.

We describe a preterm infant of 32 weeks' gestation with hydrops fetalis due to intrauterine supraventricular tachycardia. On the second day of life, cranial ultrasound showed a mainly right-sided periventricular leukomalacia already with porencephalic cysts. These findings were confirmed by autopsy. An association of intrauterine tachycardia with periventricular leukomalacia must be assumed.

Adult↗
PubMed1993

[31P-cardio-MR-spectroscopy in myocardial insufficiency].

The relative linear relationships of creatine phosphate/gamma-adenosine triphosphate (PCr/ATP) and of phosphodiester (PDE)/ATP were measured in 38 normals and 27 patients with cardiac insufficiency using cardiac 31P-MR-spectroscopy. There was no significant difference between normals and those with dilated cardiomyopathy (19 cases) and severe aortic valve lesions (8 cases), irrespective of the clinical stage of the cardiac abnormality. Within subgroups of insufficiency there was a correlation between PCr/ATP and the severity of the disease with significant differences between mild and severe cardiac insufficiency. In 6 patients a significant rise in PCr/ATP could be demonstrated following clinical improvement under drug therapy. There was no correlation between the relative linear relationship and the left ventricular ejection fraction.

Adult↗
PubMed1993

TGN38/41 recycles between the cell surface and the TGN: brefeldin A affects its rate of return to the TGN.

TGN38 and TGN41 are isoforms of an integral membrane protein (TGN38/41) that is predominantly localized to the trans-Golgi network (TGN) of normal rat kidney cells. Polyclonal antisera to TGN38/41 have been used to monitor its appearance at, and removal from, the surface of control and Brefeldin A (BFA)-treated cells. Antibodies that recognize the lumenal domain of TGN38/41 are capable of specific binding to the surface of both control and BFA-treated cells. In both control and BFA-treated cells internalized TGN38/41 is targeted to the TGN; however, there are differences in 1) the morphology of the intracellular structures through which TGN38/41 passes and 2) the kinetics of internalization. These data demonstrate that TGN38/41 cycles between the plasma membrane and the TGN in control and BFA-treated cells and suggest that recycling pathways between the plasma membrane and the TGN exist for predominantly TGN proteins as well as those that normally cycle to other intracellular compartments. They also demonstrate that addition of BFA not only alters the morphology and localization of the TGN but also the kinetics of endocytosis.

Animals↗
PubMed1993

Cardiac dysfunction and development of heart failure.

A major consequence of chronic cardiac dysfunction is chronic overload of contractile myocardium. Various aetiologies, in reaction to this, may induce compensatory mechanisms consisting of excentric (dilatation) and concentric hypertrophy. Chronic left ventricular dysfunction is caused most frequently by myocardial infarction. Left ventricular dilatation and hypertrophy occurs in patients with extensive infarction. Dilatation may at first be compensatory, restoring stroke volume within 4 weeks of the infarct. However, as dilatation progresses, left ventricular ejection fraction and stroke volume deteriorate during exercise and at rest, and finally pulmonary capillary wedge pressure increases and patients become symptomatic 1.5-3 years after the infarct. Major determinants of progressive left ventricular dilatation and deterioration of haemodynamics are a depressed left ventricular ejection fraction, angiographically determined infarct size, stroke volume early (4 days) after myocardial infarction, infarct location (anterior/inferior) and the grade (TIMI) of perfusion of the infarct-associated coronary artery. Chronic loading and unloading may accelerate or decelerate this process. Efficiency and energy reserve (phosphocreatine) of the dilated ventricles is reduced. Further intrinsic changes in surviving myocardium include morphological and functional disturbance of coronary microcirculation.

Cardiomegaly↗
PubMed1993

Hepatitis B virus infection in liver allografts.

Liver transplantation of hepatitis B surface antigen (HBsAg)-positive patients has been associated with high morbidity and mortality secondary to hepatitis B (HB) recurrence in the graft. Eight patients of the Queensland Liver Transplant Service were HBsAg positive pretransplant. Six acquired HB infection of the graft, one developed serological recurrence of HB before early death from sepsis, and one HB e antigen-negative patient permanently cleared the virus. HB-infected grafts showed early expression of viral antigen, acute hepatitis, fibrosing cholestatic hepatitis, chronic active hepatitis, cirrhosis, or minimal changes associated with a carrier state. Only in the latter case was HB mild and nonprogressive. Cases of fibrosing cholestatic hepatitis progressed rapidly to liver failure; they showed fibrosis and plates of ductular epithelium extending from portal tracts into lobules, cholestasis, ballooning of hepatocytes, and prominent hepatocyte expression of viral antigens. Perioperative HB immunoglobulin proved ineffective in preventing HB recurrence. One other patient became HBsAg positive for the first time after retransplantation; he developed severe acute hepatitis, then chronic active hepatitis. Our biopsy findings support the view that, in liver allografts, the HB virus may be directly cytopathic.

Acute Disease↗
PubMed1993

Cytomegalovirus myelitis in perinatally acquired HIV.

A 7 year old child perinatally infected with HIV who died from progressive muscular paralysis and central nervous respiratory failure is described. Cytomegalovirus (CMV) prophylaxis with a special intravenous CMV hyper-immunoglobulin had been successfully conducted for more than four years. Macroscopic and microscopic immunohistochemical examination of the spinal cord revealed a diffuse CMV infiltration of the entire myelon. CMV infected cells were identified as astrocytes, oligodendrocytes, neurons, macrophages, ependymal, endothelial, and Schwann cells. Other organs had no signs of CMV infection. Central nervous spinal CMV infection was most probably due to insufficient penetration of the blood-brain barrier by the CMV hyper-immunoglobulin. In suspicious cases early spinal magnetic resonance imaging (1.5 tesla) combined with an examination of urine and cerebrospinal fluid for CMV is recommended.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Ocular findings in a family with autosomal dominant retinitis pigmentosa and a frameshift mutation altering the carboxyl terminal sequence of rhodopsin.

A family is described in which an 8 base pair deletion (nucleotides 5252-5259, codons 341-343) of the rhodopsin gene cosegregates with autosomal dominant retinitis pigmentosa (adRP). The deletion results in a shift in the reading frame, causing a rhodopsin molecule extended by one residue and substantially altered at the carboxyl terminus. Phenotypic expression is relatively mild. In affected members, night blindness did not occur before the age of 16, and late onset of visual field loss was consistently reported. Even older individuals (59 and 76 years) had preserved central islands in the visual field; a younger female patient had normal visual fields until the age of 34. ERG and psychophysical tests showed well preserved cone function at stages of virtually abolished rod function. Phenotypic differences and similarities between this form of adRP and others associated with mutations at the carboxyl terminus of the rhodopsin molecule are discussed. The cause of RP by mutations in this region remains to be clarified.

Adult↗