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Biomedical subjects

K Heller

Publications and source records attributed to K Heller.

At least 55 records · Page 3Linked to original sources
PubMed1995

Treatment with beta-adrenergic blocking agents after myocardial infarction: from randomized trials to clinical practice.

OBJECTIVES: Our aim was to determine the percent of patients with myocardial infarction who are treated with beta-adrenergic blocking agents in dosages proved to be effective in preventing death after a heart attack. BACKGROUND: In the prospective randomized trials showing that beta-blocker treatment improves survival rates after myocardial infarction, relatively high dosages of these agents were used. However, it is not known whether these dosages are used in current clinical practice. METHODS: In a retrospective analysis of clinical data from 606 consecutive survivors of myocardial infarction at four university hospitals in three countries, we assessed the number of infarct survivors receiving prospectively defined "effective dosages" of beta-blockers. We defined these dosages as those that demonstrated improved survival rates of infarct survivors who received active drug in large, prospective, double-blind, placebo-controlled trials. RESULTS: Only 58% of infarct survivors with no contraindications to beta-blockers received these drugs at the time of hospital discharge, and only 11% received dosages equivalent to > 50% of the effective dosages. Independent predictors of failure to prescribe beta-blockers to infarct survivors without contraindications to these drugs were the use of diuretic agents, transient heart failure, impaired left ventricular function and increased patient age. Among patients receiving beta-blockers, only the use of propranolol predicted prescription of a low beta-blocker dosage. CONCLUSIONS: Failure to prescribe beta-blockers after myocardial infarction is common but in most cases is not due to clear contraindications. Many patients not receiving beta-blockers belong to subgroups that would derive the greatest benefit from such treatment. Finally, even when beta-blockers are prescribed, the dosages used are considerably lower than those proved to be effective in preventing death after myocardial infarction.

Adrenergic beta-Antagonists↗
PubMed1995

Alternative splicing in human retinal mRNA transcripts of an opsin-related protein.

An opsin-related gene encodes a putative RPE-retinal G-protein-coupled receptor (RGR) that is most homologous to the visual pigments and invertebrate retinochrome. A splice variant of human RGR mRNA can be demonstrated by the sequence of isolated cDNA clones and by the amplification and analysis of human retinal mRNA. The shortened transcript contains a deletion of 114 nucleotides that correspond exactly to the sequence of exon 6 in the human rgr gene. The predicted RGR variant lacks the putative sixth transmembrane domain and has a calculated molecular weight of 27,726. Variable amounts of a 28-kDa protein were found in the retinas of some individuals by immunoblot assay. Since a similar shortened RGR transcript was not detected in bovine retina or RPE, the RGR variant is not essential for vertebrate vision. Analysis of the structure of the rgr gene and of the sequences of cDNA clones indicates that the truncated mRNA may be produced through alternative splicing of pre-mRNA from which a cassette exon is removed and the predicted RGR variant is radically altered in primary structure.

Base Sequence↗
PubMed1994

Recruitment challenges in studying late-life depression: do community samples adequately represent depressed older adults?

Although research on late-life depression is burgeoning, little attention has been given to the sampling and recruitment obstacles encountered in trying to enlist the participation of older adults in such studies. In this article, the authors summarize the response rates of 15 recent epidemiological studies and 100 descriptive studies examining late-life depression among community-dwelling older adults. These studies excluded approximately 25-35% of potential participants. The authors present evidence suggesting that because depressed older adults may be especially likely to refuse research invitations, researchers may overlook or underestimate important correlates of depression. In addition, the authors describe several strategies for enhancing recruitment efforts.

Aged↗
PubMed1994

[Potentially dangerous moments in use of esophageal balloon tamponade. 4 case reports with critical analysis of the literature].

In general, balloon tamponade is still part of the therapy of bleeding esophageal varices, despite effective sclerotherapy. Four case reports demonstrate that the application of balloon tamponade may be associated with severe complications. Moreover, a critical analysis of the literature shows a very different handling with respect to volume of gastric balloon, duration of blockade and traction to the tube. To prevent serious side effects, a safe way is described in detail when using balloon tamponade.

Aged↗
PubMed1993

[Orthotopic liver transplantation with arterial re-anastomosis in the rat--a detailed description of technique and analysis of possible errors].

Liver transplantation (LTX) in the rat is a frequently used transplantation model. In the present study we give a detailed description of the suture technique for all anastomoses, except the bile duct, with arterialization of the transplanted liver over an aortoceliac segment to the recipient's aorta. Using this technique, we finally achieved survival rates of 80%. During the development stages, the main cause of death was an exceedingly long anhepatic time (> 20 min); later on, complications occurred only from insufficient anastomoses. The advantage of the suture technique over the cuff technique is that a more physiological anastomosis is obtained with less trauma to the recipient when using rearterialization. Despite the complicated suture technique, the anhepatic time can be well reduced to below 20 min.

Anastomosis, Surgical↗
PubMed1993

Distinction between quality and quantity of problem-solving responses among depressed older women.

The purpose of this project was to investigate the extent to which depressed and nondepressed community-dwelling older women differed in their problem-solving responses to vignettes describing problematic situations common in this population. Contrary to expectations, the depressed and nondepressed older women showed an equal capacity to follow traditional problem-solving steps. There were differences, however, in the quality of solutions generated for dealing with social isolation and interpersonal conflict as judged by peer evaluators. Further work is needed in understanding the components of effective problem solving most important for adjustment to real-life difficulties.

Adaptation, Psychological↗
PubMed1992

Clonidine for patients with rapid atrial fibrillation.

OBJECTIVE: To determine whether clonidine can slow ventricular rate in patients with rapid atrial fibrillation. DESIGN: Randomized, controlled trial, with a 4-hour follow-up period. SETTING: Emergency room of a university hospital. PATIENTS: A consecutive sample of 18 hemodynamically stable patients who were evaluated or treated for rapid atrial fibrillation. Exclusion criteria included acute or terminal illness; current use of antiarrhythmic agents, calcium-channel blockers, or beta-blockers; excessive hypertension; pulmonary, valvular, or pericardial disease; and electrolyte imbalance. INTERVENTIONS: Patients were randomly assigned to receive either "no treatment" (control group) or clonidine, 0.075 mg orally, at baseline and after 2 hours if heart rate did not decrease by at least 20%. MEASUREMENTS: Blood pressure was measured by the same nurse in the same arm for 4 consecutive hours, and a full 12-lead electrocardiographic evaluation was done. MAIN RESULTS: Heart rate decreased to below 100 beats/min in eight of nine patients receiving clonidine compared with two of nine patients in the control group. The difference in the mean decreases in heart rate was 38 beats/min (95% CI, 20 to 56 beats/min). Six patients who were treated with clonidine and one patient in the control group reverted to normal sinus rhythm. Systolic blood pressure decreased slightly in both groups, without significant differences. Clinical follow-up was uneventful. CONCLUSION: Low-dose clonidine was an easy, efficient, and effective treatment for patients with rapid atrial fibrillation who were hemodynamically stable.

Adrenergic alpha-Agonists↗
PubMed1992

Morphometric comparisons of optic nerve axon loss in acquired immunodeficiency syndrome.

Axonal degeneration and diminution of the axonal population in the optic nerve have been documented in aging and in various neuro-ophthalmic conditions. We applied morphometric techniques to the postmortem examination of optic nerves obtained from patients with acquired immunodeficiency syndrome. Twelve optic nerves (eight from patients with AIDS and four from age-matched control eyes) were stained with paraphenylenediamine and morphometrically analyzed with a computer-assisted image and measurement system. Degeneration was often severe and was scattered throughout all of the AIDS-affected optic nerves. In the AIDS-affected optic nerves, the mean axonal population was markedly lower than the mean obtained from normal optic nerves (880,000 vs 1,507,000). Despite the approximate 40% loss of axons, mean axonal diameters were not markedly different, suggesting that no particular class of axon was especially susceptible to AIDS-associated degeneration. The extent and pattern of axonal loss in optic nerves of patients with AIDS suggest that the changes may not only be secondary to damage at the retina, but may reflect an AIDS-associated primary optic neuropathy.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Central hamartoma of the liver in a child.

A two-year-old girl was found to have a hamartoma of the liver located centrally in the hilar region. Despite the benign character of this lesion severe biliary obstruction developed rapidly and made surgical therapy necessary. The surgical approach, with reference to the literature, is discussed.

Child, Preschool↗
PubMed1991

[Endoscopy, shockwave lithotripsy and local lysis in complicated pigmentary calculi of extra- and intrahepatic bile ducts].

Endoscopy, extracorporeal shockwave lithotripsy (ESWL) and local lysis with alkaline solution of EDTA and bile salts in water were applied in combination in four patients with extra- and intrahepatic pigment stones as well as calcium bilirubinate covered concrements of the biliary tract. In the first patient (a man aged 80 years) a giant concrement of the bile duct was broken up after ESWL by three weeks of local chemical lysis and the fragments were removed by endoscopy. In the second case (man, aged 72), a nonextractable pigment stone was at first reduced in size by four-day local lysis and then removed endoscopically. Intrahepatic pigment stones were completely removed in the other two patients (boy of 12, man of 62) by local lysis only in 3 and 15 weeks, respectively. Even long-term use of the alkaline solution may not cause any serious side effects. Breaking up of stones after size reduction with ESWL of giant stones, size reduction of intact stones and contact lysis of intrahepatic stones are three important indications for chemical dissolution of biliary tract stones, respectively.

Adolescent↗
PubMed1991

Peer support telephone dyads for elderly women: was this the wrong intervention?

Tested a preventive intervention in which peer telephone dyads were developed for low-income, community-living, elderly women with low perceived social support. After an initial assessment, respondents were randomly assigned to either an assessment-only control or received 10 weeks of friendly staff telephone contact. After a second assessment, participants receiving the staff contact were randomly assigned to continue that contact or were paired in dyads to continue phone contact with one another. Dependent variables were measures of perceived social support, morale, depression, and loneliness. All groups, particularly the staff contact group, showed some improvement in mental health scores over time, but there were no significant differences between intervention groups, or between intervention and assessment-only control groups. The results suggest that participation in the study and in personal assessment interviews at home were probably morale enhancing, and that additional telephone contact did not significantly add to that effect. Evidence also indicates that, in this sample, low perceived family support was significantly related to poor mental health, so it is possible that a program designed to increase friend support may have been the wrong intervention.

Aged↗
PubMed1991

Support interventions for older adults: confidante relationships, perceived family support, and meaningful role activity.

The rationale and problems encountered in implementing a peer-support telephone intervention are described. The research conducted by Heller, Thompson, Trueba, Hogg, and Vlachos-Weber (1991) was based on epidemiological literature documenting the moral enhancing value of confidante relationships. However, that literature may be insufficiently precise to form the basis for an intervention without prior ethnographic study of the local target population. Furthermore, the positive effects of peer friendships may refer to long established relationships rather than to newly formed social ties. It is concluded that future support intervention research with older adults should concentrate on reinforcing meaningful role activities, and that greater attention should be given to strengthening indigenous ties before attempting to create new ones. While prior process research and formative evaluation are of value, we also emphasize the importance of well-controlled field studies in the ultimate test of intervention hypotheses.

Aged↗