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Biomedical subjects

J Berg

Publications and source records attributed to J Berg.

At least 37 records · Page 2Linked to original sources

Isoenzyme-specific cyclooxygenase inhibitors: a whole cell assay system using the human erythroleukemic cell line HEL and the human monocytic cell line Mono Mac 6.

NSAIDs inhibit the conversion of arachidonic acid into Prostaglandin G2 and Prostaglandin H2 which is catalyzed by the enzyme cyclooxygenase (COX). Two genetically distinct isoforms have been discovered, COX-1 and COX-2. While COX-1 is thought to account for homeostatic amounts of eicosanoids, COX-2 is induced during inflammation leading to pathologic amounts of eicosanoids. Since NSAIDs inhibit both COX isoforms, antiinflammatory drug research has refocused to discovering COX-2 inhibitors that do not inhibit COX-1. For this purpose, we have developed a whole cell assay system using the human erythroleukemic cell line HEL as a source for COX-1 and the human monocytic cell line Mono Mac 6 as a source for COX-2. Mono Mac 6 cells express high amounts of COX-2 upon stimulation with lipopolysaccharide (LPS) in the absence of any detectable COX-1 protein. On the other hand, we find HEL cells to naturally express COX-1 protein, but not COX-2. Testing of a panel of NSAIDs as well as some COX-2 specific inhibitors showed that this assay system is suitable for identifying compounds that selectively inhibit either COX-1 or COX-2. This test system offers the advantage of assessing COX-1 and COX-2 inhibitors within the human species, within a similar test set-up, and circumvents the need for tedious purification of either platelets or peripheral blood monocytes.

Anti-Inflammatory Agents, Non-Steroidal

An evaluation of a self-management program for adults with asthma.

The purpose of this study was to evaluate the impact of a self-management program for adults with moderate to severe asthma on compliance with inhaled, prescribed, nonemergency medications; asthma symptoms; and airway obstruction. In this controlled experimental study, 55 subjects from a rural community were randomized to one of two groups. Self-efficacy theory served as the framework for this study. Primary measures included the Metered Dose Inhaler (MDI) Chronolog, a journal of daily asthma concerns, and a peak-flow meter to appraise airway obstruction. Secondary measures included the Asthma Self-Management Assessment Tool (ASMAT) and the Self-Efficacy for Asthma Management Scale (SEAMS). These measures were completed pre- and post-intervention. Data analysis using descriptive and inferential statistics revealed that subjects receiving the self-management program increased compliance with inhaled medications (U = 271, p = .043).

Adolescent

Microsporidia in humans.

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AIDS-Related Opportunistic Infections

Canine osteosarcoma: amputation and chemotherapy.

One of the most important advances in veterinary oncology during the past 10 years has been the use of adjuvant chemotherapy for treatment of the micrometastases of canine osteosarcoma. This article reviews the biologic behavior of osteosarcoma and discusses chemotherapy with the two agents known to be effective: cisplatin and doxorubicin.

Amputation, Surgical

Transcranial Doppler detection of microemboli in prosthetic heart valve patients: dependency upon valve type.

Transcranial Doppler ultrasound has revealed the existence of cerebrovascular microemboli in asymptomatic patients with prosthetic heart valves. We investigated the relation between the presence and number of emboli signals and valve type. Patients with six types of prosthetic valves (Björk-Shiley monostrut, Medtronic-Hall, Carbomedics, ATS, Carpentier-Edwards standard, Carpentier-Edwards supraannular) were examined using transcranial Doppler ultrasound in two centers. The monitoring time was 30 min over the right middle cerebral artery. All patients were stabilized on warfarin at the time of study. Microemboli signals were identified by their characteristic audiovisual signal and on subsequent spectral analysis, based on accepted criteria. A standard neurologic questionnaire was completed by all patients. The prevalence of microemboli signals varied between 49% (Medtronic Hall) and 97% (Björk-Shiley monostrut), while their number varied between 1 [0-3] (Carpentier-Edwards standard) and 187 [136-240] (Björk-Shiley monostrut) per hour (median and 95% CI). Both parameters were significantly higher in patients with Björk-Shiley monostrut valves compared to the other patient groups. There were no significant differences in the prevalence of neurologic complications among the groups examined (overall 16%), or in emboli numbers between symptomatic and asymptomatic patients. The prevalence and quantity of microemboli signals in patients with prosthetic heart valves, as detected by transcranial Doppler, is dependent upon valve type. The clinical significance of these microemboli signals remains to be further evaluated.

Aged

Disseminated microsporidiosis especially infecting the brain, heart, and kidneys. Report of a newly recognized pansporoblastic species in two symptomatic AIDS patients.

Microsporidia have emerged as important opportunistic AIDS pathogens of the alimentary, respiratory, and urinary tracts. Although nonhuman mammalian microsporidia infections typically include encephalitis, CNS microsporidiosis has not been reported in patients with AIDS. A 33-year-old white male and an 8-year-old black girl presented with seizures and declining mental status. Central nervous system (CNS) imaging studies revealed small peripherally and diffusely enhancing lesions present for at least 2 and 4 months before death, respectively. Both patients expired despite empirical anti-toxoplasma therapy. Their brains contained innumerable soft gray matter lesions that consisted of central areas of necrosis, filled with free spores and spore-laden macrophages, surrounded by microsporidia-infected astrocytes. The complete autopsy of the child also revealed necrotizing and sclerosing cardiac and renal microsporidiosis and infection of the pancreas, thyroid, parathyroids, liver, spleen, lymph nodes, and bone marrow. Infected cells included astrocytes, cardiac myocytes, epithelium, endothelium, vascular smooth muscle cells, hepatocytes, adipocytes, Schwann cells, and macrophages. Light and electron microscopic studies revealed pansporoblastic development within thick-walled sporophorous vacuoles of parasite origin. Although most similar to Pleistophora sp and Thelohania sp, this microsporidian is different from any known species. Microsporidiosis should be considered as the possible cause of a wide range of diseases in AIDS patients, including CNS, cardiac, and renal.

AIDS-Related Opportunistic Infections

Permeability properties of the intact mammalian bladder epithelium.

Because the mammalian bladder must store urine of composition which differs markedly from that of plasma for prolonged periods, the bladder permeability barrier must maintain extremely low permeabilities to substances which normally cross membranes relatively rapidly, such as water, protons, and small nonelectrolytes like urea and ammonia. In the present studies, permeabilities of the apical membrane of dissected rabbit bladder epithelium to water, urea, ammonia, and protons were measured in Ussing chambers and averaged (in cm/s) for water, 5.15 +/- 0.43 x 10(-5); for urea, 4.51 +/- 0.67 x 10(-6); for ammonia, 5.14 +/- 0.62 x 10(-4); and for protons, 2.98 +/- 1.87 x 10(-3), respectively. These permeability values are exceptionally low and are expected to result in minimal to no leakage of these normally permeable substances across the epithelium. Water permeabilities in intact whole rabbit bladders were indistinguishable from those obtained in the dissected epithelial preparation. Moreover, addition of nystatin to the apical solution of dissected epithelia rapidly increased water permeability in conjunction with loss of epithelial resistance. These results confirm that the apical membrane of the bladder epithelial cells represents the bladder permeability barrier. In addition, they establish a model system that will permit examination of how membrane structure reduces permeability and how epithelial injury compromises barrier function.

Ammonia

Quality of life in COPD patients using transtracheal oxygen.

Transtracheal oxygen offers patients with chronic obstructive pulmonary disease many benefits. A qualitative study was conducted to examine patients' perceptions of how the technology affects quality of life. This study has several implications for nurses working in hospital and home settings.

Activities of Daily Living

Ultrasonography of the brain and vertebral canal in dogs and cats: 15 cases (1988-1993).

Medical records of 3 cats and 12 dogs with lesions of the brain (3 cats, 2 dogs) or vertebral canal (10 dogs) that underwent intraoperative ultrasonography were reviewed. Ultrasonography was performed after craniotomy, a ventral slot procedure, or laminectomy, using a real-time sector scanner with a 7.5- or 10-MHz transducer. In the 3 cats and 2 dogs with brain lesions, cerebral masses were hyperechoic, compared with normal brain, and were easily located. In the 2 dogs, ultrasonography was necessary to localize deep-seated cerebral lesions that could not be seen following craniotomy. In 7 dogs that underwent a ventral slot procedure because of prolapse of an intervertebral disk, ultrasonography was successfully used to assess completeness of disk removal. The remaining 3 dogs underwent dorsal laminectomy because intradural enlargement of the spinal cord (1 dog) or an intradural mass (2 dogs) could be seen myelographically. In the 2 dogs with intradural masses, intraoperative ultrasonography helped to delineate the extent of the tumor. In the third dog, spinal cord swelling was seen ultrasonographically; the histologic diagnosis was spinal cord edema.

Animals

Results of surgery and doxorubicin chemotherapy in dogs with osteosarcoma.

Thirty-five dogs with appendicular osteosarcoma were treated with 5 doses of doxorubicin (30 mg/m2 of body surface, i.v., every 2 weeks). Surgical excision of the primary tumor was performed 13 days after the second (n = 18) or third (n = 17) treatment, and the subsequent doxorubicin treatment was given the day following surgery. Resected tumors were evaluated histologically to determine response to preoperative chemotherapy (ie, percentage of the tumor that was necrotic). Survival data for the 35 dogs were compared with survival data for a historical control group, consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Administration of doxorubicin at 2 week intervals was well tolerated. Three dogs were alive and did not have evidence of disease at the time of reporting. Of the remaining 32 dogs, 3 died or were euthanatized because of cardiomyopathy presumably caused by doxorubicin; 1 died suddenly 116 weeks after initiation of treatment; and the remaining 28 were euthanatized because of problems documented to be related to distant metastases. Thirteen dogs (40.6%) were euthanatized because of pulmonary metastases, 10 dogs (31.3%) were euthanatized because of bone metastases, and 5 dogs (15.6%) were euthanatized because of metastases in other sites. The proportion of dogs euthanatized because of bone metastases was significantly (P < 0.001) higher for the study group than for the control group. Median survival time for the 35 dogs that received doxorubicin was estimated to be 52.3 weeks, and 1- and 2-year survival rates were estimated to be 50.5 and 9.7%, respectively. Survival time was significantly (P < 0.0001) longer for these dogs than for control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Amputation, Surgical

Is there a hemispheric side preference of cardiac valvular emboli?

Microaggregates arising from prosthetic cardiac valves offer the opportunity to examine the distribution of valvular emboli in the human cerebral circulation. Forty-four patients with different kinds of prosthetic valves underwent bilateral transcranial Doppler monitoring for 1 h to detect high intensity Doppler signals representing microemboli. Comparing the total number of embolic signals in both middle cerebral arteries (N = 1066), a side preference was not statistically evident. However, clear side preferences were obvious in some individuals. The lack of statistical evidence for hemispherical preferences of cardiac microembolism in general does not exclude selective streaming in individuals, explaining the clinical observation of lodging preferences of recurrent cardiac embolism. A cardiac source of microembolism may mimic disease activity of extracranial carotid artery stenosis and bias the localization of embolic source.

Adult

Opitz BBBG syndrome: new family with late-onset, serious complication.

The Opitz BBBG syndrome is characterized by hypertelorism and (in male patients) hypospadias, in addition to a number of midline abnormalities: posterior laryngeal cleft, stridor, swallowing dysfunction, cardiac defects, imperforate anus, and urinary tract and CNS anomalies. Inheritance is autosomal dominant (McKusick number *145410) with partial male sex limitation in most pedigrees. We report a Dutch family with Opitz BBBG syndrome in which the proband developed late-onset symptoms of a structural laryngeal abnormality.

Abnormalities, Multiple

CAVIAR: a tool to improve serial analysis of the 12-lead electrocardiogram.

An important part of an electrocardiogram (ECG) interpretation is the comparison between the present ECG and earlier recordings. The purpose of the present study was to evaluate a combination of two computer-based methods, synthesized vectorcardiogram (VCG) and CAVIAR, in this comparison. The methods were applied to a group of 38 normal subjects and to a group of 36 patients treated with anthracyclines. A fraction of these patients are likely to develop cardiac injury during or after the treatment, since anthracyclines are known to cause heart failure and cardiomyopathy. Two ECGs were recorded on each patient, one before and one after the treatment. On each normal subject, two ECGs were recorded with an interval of 8-9 years. A synthesized VCG was calculated from each ECG and the two synthesized VCGs from each subject were analysed with the CAVIAR method. The CAVIAR analysis is a quantitative method and normal limits for four measurements were established using the normal group. Values above these limits were more frequent in the patient group than in the normal group. The conventional ECGs were also analysed visually by an experience ECG interpreter without knowledge of the result of the CAVIAR analysis. No significant serial changes were found in 10 of the patients with high CAVIAR values. Changes in the ECGs were found in two patients with normal CAVIAR values. In summary, synthesized VCG and CAVIAR could be used to highlight small serial changes that are difficult to find in a visual analysis of ECGs.

Adult

Variability of Doppler microembolic signal counts in patients with prosthetic cardiac valves.

BACKGROUND AND PURPOSE: The purpose of this study was the evaluation of intraobserver, interobserver, and intrasubject variability in the Doppler detection of microembolic signals in patients with mechanical prosthetic valves. Simultaneously, the feasibility of automated embolus detection by means of a neuronal network was investigated. METHODS: From 25 patients with mechanical prosthetic heart valves, single transcranial Doppler monitoring sessions of 30 minutes' duration were recorded on videotape, randomized, and subsequently analyzed by eight independent trained observers from three centers. Three observers evaluated these tapes on three separate occasions, blinded to their previous results. An additional 48 patients with prosthetic heart valves were repetitively monitored with transcranial Doppler ultrasonography for 30 minutes three times within 1 year to examine the long-term variability in the occurrence of microembolic signals. Finally, in an effort to assess the short-term intrasubject variability, 20 patients were examined for 90 minutes, and the results of the three 30-minute periods were compared. The interobserver, intraobserver, and intrasubject (both short- and long-term) variability was evaluated. RESULTS: No significant differences in microembolic signal counts were found among the different observers, between the human observers and the neuronal network, or among the three separate evaluations of stored data by the same observer. The same was true for repeat examinations of the same patient (P > .05, Student's two-paired t test and Friedman's test). CONCLUSIONS: The detection of microembolic signals in patients with prosthetic cardiac valves is a reproducible technique. The reliable performance of the neuronal network argues for a broader use of this device. The intrasubject stability of the microembolic rate over 1 year supports the concept that the underlying emboligenic process is associated with intrinsic mechanical properties of the valve implant and not due to a thromboembolic process in the heart.

Cerebral Arteries