Search PubMed⌕ Search

Biomedical subjects

B Carlson

Publications and source records attributed to B Carlson.

At least 73 records · Page 4Linked to original sources

Managed care is here ... and growing. Are you involved? Prepared? If not, you should be.

As managed care evolves in Michigan, one message is clear: physicians are key players and therefore, must get involved. After all, as Allan Dobzyniak, MD, explains in the following article, "Physicians are the people who control utilization, the people who are uniquely in a position to control quality, and the people who are uniquely in a position to give value to the health care dollar." While there are risks, the evolution of managed care provides physicians with a solid opportunity to accomplish something in terms of on-going health care management. The following article provides a status report on managed care in Michigan, plus a comprehensive examination of its inherent risks and opportunities for physicians and patients.

Managed Care Programs↗

Changes in satellite cell mitotic activity during acute period of unilateral diaphragm denervation.

The acute period of unilateral diaphragm denervation (DNV) is associated with increases in cell mitotic activity, protein synthesis, and muscle fiber hypertrophy. Our purpose was to determine whether acute unilateral diaphragm DNV is associated with changes in muscle isometric contractile properties, cross-sectional area of different muscle fiber types, mitotic activity of muscle fiber satellite cells, and muscle fiber ultrastructural properties indicative of injury. Adult male Fischer 344 rats underwent a right phrenicotomy, and DNV and intact (INT) hemidiaphragms were studied 72 h later. DNV hemidiaphragm displayed a significant decline in maximal isometric force (8.7 vs. 24.3 N/cm2) and a prolonged time to peak twitch force (47.8 vs. 37.5 ms) and time to half relaxation (72.3 vs. 44.3 ms) compared with INT contralateral hemidiaphragm (P < 0.05). DNV resulted in a significant increase in cross-sectional area of types I (33%), IIa (35%), and IIb (28%) fibers relative to INT hemidiaphragm (P < 0.05). Satellite cell mitotic activity (assessed by incorporation of bromodeoxyuridine) was approximately 5.5 times greater in DNV than in INT muscle (DNV 25.0 +/- 3.8, INT 4.5 +/- 1.4 labeled satellite cell nuclei/1,000 nuclei; P < 0.05). Ultrastructural examination of electron micrographs revealed alterations in Z-line and sarcomeric structure indicative of muscle injury. Cellular infiltration and segmental necrosis were also noted in some fibers. We conclude that acute unilateral diaphragm DNV results in muscle fiber injury that induces satellite cell activation. We also speculate that the specific force decrement associated with DNV is at least partially the result of muscle injury.

Animals↗

Discrimination ability in patients with extensive fixed partial dentures on mandibular canine teeth.

To study discrimination ability under different test situations, a psychophysiologic test was performed in a group of patients with 12-unit mandibular fixed partial dentures supported on the 2 canines. The cantilever segments were exchangeable. Analyses of discrimination ability were performed with regard to periodontal and endodontic status of the abutment teeth and to type of mucosal contact in cantilever regions. Discrimination ability was markedly reduced with a strongly reduced periodontal bone contact area. The endodontic status did not affect discrimination ability. A tendency towards better discrimination ability was seen when the cantilever sections without mucosal contacts were compared with those with mucosal contacts through pontics or saddles.

Alveolar Bone Loss↗

Selective effects of mastoparan analogs: separation of G-protein-directed and membrane-perturbing activities.

Mastoparan (MP), a wasp venom peptide, is known both to interact with G-proteins and to alter membrane structure and function. To determine the structural requirements for these two aspects of MP action, we constructed several analogs of the peptide and characterized them using Swiss 3T3 cell membranes. The effects of these peptides were measured on: i) G-protein-mediated stimulation of phospholipase-C activity by GTP gamma S and bombesin and ii) the membrane enzyme activities, calcium-activated phospholipase-C and Na,K-ATPase. MP strongly inhibited all the above activities and caused membrane permeabilization. Substitution of one Lys residue by Gly at either the N- or C-terminal of the MP molecule resulted in peptides which selectively inhibited G-protein stimulated phospholipase-C with no or very slight membrane-perturbing effects. Introduction of additional Lys residues to MP led to the opposite effect. Thus, G-protein modulating and membrane disrupting actions of MP appear to be not necessarily linked, and may be separated.

3T3 Cells↗

An ergonomic evaluation of nursing assistants' job in a nursing home.

Thirty-eight nursing assistants (NAs) in a nursing home ranked and rated 16 different patient handling tasks for perceived stresses to the low back. The nursing assistants were observed for 79 4 h shifts and were videotaped for 14 4 h shifts to describe a typical workday and to determine the number of patient-handling tasks performed per shift, the use of assistive devices, and biomechanical stresses to the low back. In addition, data were collected on nursing assistants' and patients' characteristics. The top eight ranked tasks included transferring patient from toilet to wheelchair (WC), WC to toilet, WC to bed, bed to WC, bathtub to WC, chairlift to WC, weighing patients and lifting patients up in bed. The mean ratings of perceived exertion for these tasks were between 'somewhat hard' and 'hard'. The estimated compressive force on L5/S1 disc for the 50th percentile patient weight ranged from 3.7 to 4.9 KN. Nursing assistants worked in teams of two and performed 24 patient transfers per 8 h shift by manually lifting and carrying patients. Assistive devices (a hydraulic lift and gait belt) were used less than 2% of the time. Patient safety and comfort, lack of accessibility, physical stresses associated with the devices, lack of skill, increased transfer time, and lack of staffing were some of the reasons for not using these assistive devices. Environmental barriers (such as confined workplaces, an uneven floor surface, lack of adjustability of beds, stationary railings around the toilet, etc.) made the job more difficult. Nursing assistants had a high prevalence of low-back pain and 51% of nursing assistants visited a health care provider in the last three years for work related low-back pain.

Accidents, Occupational↗

Heterologous expression and secretion of a Streptomyces scabies esterase in Streptomyces lividans and Escherichia coli.

The esterase gene from Streptomyces scabies FL1 was cloned and expressed in Streptomyces lividans on plasmids pIJ486 and pIJ702. In S. lividans, the esterase gene was expressed during later stages of growth and was regulated by zinc, as is seen with S. scabies. The 36-kDa secreted form of the esterase was purified from S. lividans. N-terminal amino acid sequencing indicated that the processing site utilized in S. lividans for the removal of the signal sequence was the same as that recognized for processing in S. scabies. Western blots (immunoblots) revealed the presence of a 40-kDa precursor form of the esterase in cytoplasmic extracts. A 23-amino-acid deletion was introduced into the putative signal sequence for the esterase. When this deleted form of the esterase was expressed in S. lividans, a cytoplasmic 38-kDa precursor protein was produced but no secreted esterase was detected, suggesting the importance of the deleted sequence for efficient processing and secretion. The esterase gene was also cloned into the pUC119 plasmid in Escherichia coli. By using the lac promoter sequence, the esterase gene was expressed, and the majority of the esterase was localized to the periplasmic space.

Alkaline Phosphatase↗

Non-erotic self-choking in five psychiatric inpatients.

Recurrent self-choking without suicidal intent has received limited attention in the literature; most reports have focused on the sexual nature of the behavior. The authors describe five psychiatric inpatients who engaged in repeated non-erotic self-choking. Similarities in clinical features of the cases include a history of substance abuse (including abuse of volatile substances), aggressive behaviors, a chronic history of psychotic symptoms leading to repeated long-term hospitalizations, and a sense of relief or pleasure, but no overt sexual stimulation, caused by self-choking. The possible role of limbic system dysfunction in this behavior is considered.

Adult↗

Removal of benign intraoral masses using the CO2 laser.

Benign soft tissue lesions of the mouth can be removed using the CO2 laser. This type of laser surgery is faster and offers less postoperative complication as compared with conventional surgery and electrosurgery. Presently, the CO2 laser can be used for intraoral biopsy of benign masses, gingivectomies, and frenectomies.

Adult↗

Increased phenylalanine incorporation in regenerating skeletal muscle grafts.

Skeletal muscle regenerates following grafting, but little is known about protein synthesis and its regulation during regeneration. We determined the sequence of changes in protein synthesis in rat extensor digitorum longus (EDL) muscle by the measurement of phenylalanine (Phe) incorporation into muscle protein at various times after grafting. Compared with control EDL, Phe incorporation in grafts doubled in 1 day, was four- to eight-fold greater from days 2 to 10 after grafting, and then subsided. Tissue mass (wet weight) increased rapidly from days 7 to 20 in EDL grafts. The maximal increase in protein synthesis occurred 7-10 days after grafting, whether or not the nerve was left intact. Autoradiography indicated that incorporated radioactivity was associated with regenerating muscle fibers on day 10. Deficiencies of insulin, pituitary or testicular hormones, or chronic in vivo administration of insulin, growth hormone, testosterone, or tri-iodothyronine did not substantially alter the elevation in incorporation of the Phe into muscle protein 10 days after grafting. The breakdown of EDL protein, measured in vitro simultaneously with protein synthesis, was increased five-fold, and overall protein degradation was elevated six-fold 10 days after grafting. These findings indicate that Phe incorporation is rapidly elevated following grafting of the EDL, and that by days 7-10 reflects synthesis in regenerating muscle fibers. The increase in protein synthesis associated with muscle regeneration at this time appears to be independent of innervation and anabolic hormones.

Animals↗

Comparison of isometric exercise and high volt galvanic stimulation on quadriceps femoris muscle strength.

The purpose of this study was to compare the effectiveness of both high volt galvanic current (HVG) and isometric exercise to strengthen the quadriceps femoris muscles in 17 healthy subjects. The subjects were divided into three groups. The Control Group (n = 6) received no exercise or stimulation. The Isometric Exercise Group (n = 5) performed 15 sessions of maximum isometric contractions, and the Electrical Stimulation Group (n = 6) engaged in 15 sessions of electrically stimulated isometric contractions. The Isometric Exercise Group was found to have an increase in strength significantly greater (p less than .05) than either the Control or Electrical Stimulation Group. No increase in strength was observed in either the Control or Electrical Stimulation Group. This study indicates that HVG stimulation is not as effective as isometric exercise in increasing strength in muscle.

Adult↗

Mania associated with LSD ingestion.

The authors report a patient who suffered a full-blown manic attack after ingesting LSD or an LSD analogue. The patient experienced acute symptoms of LSD intoxication, which resolved but were followed in about 3 weeks by a typical manic episode of psychotic magnitude. The mania cleared with lithium therapy.

Adult↗