Biomedical subjects
Publications and source records attributed to R Johnson.
Palatal dimensions (width, depth, and height) of 40 patients with Down's syndrome were compared to 44 control patients. The height was measured with a specially designed palatal-height gauge. The palatal dimensions of patients with Down's syndrome were narrower in width, shorter in depth, and lower in height.
The ability of soybean oil lipid emulsions to affect essential fatty acid deficiency (EFAD) and plasma fatty acid distribution was studied in neonatal pigs. The test animals were maintained on a fat-free diet prior to administration of lipid emulsion. Plasma and red blood cell (RBC) membrane levels of essential [linoleic (C-18:2 omega 6) and arachidonic (C-20:4 omega 6)] and nonessential [palmitic (C-16, palmitoleic (C-16:1 omega 7), stearic (C-18), and oleic (C-18:1 omega 9)] fatty acids and the triene:tetraene ratio [5,8,11-eicosatrienoic acid (C-20:3 omega 9):arachidonic acid (C-20:4 omega 6)] were monitored to ascertain the establishment of EFAD and its correction. Nonessential fatty acids were studied, as these components of lipid therapy have received little attention. Results indicate that soybean oil emulsions are effective in reversing fatty acid profiles found in EFAD, and both essential and nonessential fatty acids are under strict metabolic control.
We assessed the isokinetic and isometric strength and power profile of the knees of 37 patients who had a previous grade II sprain (partial tear) of the anterior cruciate ligament. Of the 37 knees, 11 had an isolated partial anterior cruciate ligament rupture and 26 had a partial anterior cruciate ligament rupture combined with a partial medial collateral ligament rupture. The Cybex II isokinetic dynamometer was used in the measurements. Eight years after the injury, the mean strength deficit of the injured knees was minimal when compared with the uninjured side. In the hamstrings of both groups, the relative strength deficit increased significantly with a higher speed of isokinetic movement (P less than 0.05). Compared with the strength parameters (peak torques), the other functional parameters (total work, average power, and peak angular impulse) of the injured knees showed some, but not significantly greater, deficits (hamstrings, 7% to 10%; quadriceps, 4% to 10%). We found that the general thigh muscle function in knees with old grade II sprains of the anterior cruciate ligament appears adequate except in flexion where the strength deficits are significantly greater in higher speeds of isokinetic movement. Therefore, rehabilitation using high-speed flexion (and extension) exercises is recommended.
To determine the ability of prophylactic knee braces to reduce or limit medial collateral and anterior cruciate ligament elongation under dynamic loading conditions, we used cadaveric specimens that had a surrogate soft tissue material that matched the tissue compliance of in vivo contracted muscles. Eight cadaveric specimens were fitted with four prophylactic knee braces and instrumented with Hall Effect Strain Transducers on both the medial collateral and anterior cruciate ligament. Each specimen was mounted in a testing frame while a lateral impact was applied to the knee joint by a pendulum at levels below the injury threshold. Legs were tested at 0 degrees and 30 degrees of knee flexion, both with and without an intact anterior cruciate ligament. The maximum elongation for each ligament was calculated as a percentage of the initial measured length. The addition of a prophylactic knee brace significantly reduced the level of impact force at the point of impact, but this did not result in a significant reduction of anterior cruciate ligament elongation for any test. Although not significant, all braces tested were more effective at reducing medial collateral ligament elongation during a lateral impact with the knee flexion at 30 degrees than at 0 degrees.
Coccidioidomycosis, a mild flulike illness in approximately 40% of infected persons, progresses to severe pulmonary or disseminated disease in 1% to 10% of symptomatic cases. We examined host genetic influences on disease severity among class II HLA loci and the ABO blood group. Participants included African-American, Caucasian, and Hispanic persons with mild or severe disseminated coccidioidomycosis from Kern County, California. Among Hispanics, predisposition to symptomatic disease and severe disseminated disease is associated with blood types A and B, respectively. The HLA class II DRB1*1301 allele marks a pre-disposition to severe disseminated disease in each of the three groups. Reduced risk for severe disease is associated with DRB1*0301-DQB1*0201 among Caucasians and Hispanics and with DRB1*1501-DQB1*0602 among African-Americans. These data support the hypothesis that host genes, in particular HLA class II and the ABO blood group, influence susceptibility to severe coccidioidomycosis.
We screened automated ambulatory medical records, hospital and emergency room claims, and pharmacy records of 2,826 health maintenance organization (HMO) members who gave birth over a 30-month period. Full-text ambulatory records were reviewed for the 30-day postpartum period to confirm infection status for a weighted sample of cases. The overall postpartum infection rate was 6.0%, with rates of 7.4% following cesarean section and 5.5% following vaginal delivery. Rehospitalization; cesarean delivery; antistaphylococcal antibiotics; diagnosis codes for mastitis, endometritis, and wound infection; and ambulatory blood or wound cultures were important predictors of infection. Use of automated information routinely collected by HMOs and insurers allows efficient identification of postpartum infections not detected by conventional surveillance.
A mail survey of 613 private veterinary practices in Indiana was conducted to determine the prevalence of canine distemper infection in Indiana during 1991 and 1992 and to compare the prevalence in three geographic regions. Of the practices that were contacted, 223 (37%) responded. Canine distemper had been diagnosed by 150 (67%) of the 223 practices. The period prevalence increased significantly from 11.1 to 16.9 cases per 10,000 dog visits. Surveillance of private veterinary practices may be useful to confirm suspected outbreaks of diseases in companion animals.
The epidemiologic features of an outbreak of canine distemper during 1992 and 1993 in pet dogs in Indiana are described. Risk factors for disease were characterized using hospital records of private veterinary practitioners. The risk of disease for purebred dogs was 85% lower than the risk of disease for mixed-breed dogs. Lack of vaccination was associated with a 350-fold increase in the risk of canine distemper, and 93.8% of all cases could be attributed to the lack of vaccination. For many of the owners, the cost of medical treatment exceeded the cost of a vaccination program.
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The laboratories of the six hospitals in Rochester, New York worked together to bid on laboratory services for local managed-care contracts. Their primary goal was to keep shrinking health-care dollars in the Rochester community while providing quality laboratory services for managed-care payers. The six laboratory providers formed a cooperative Consortium that enabled them to compete successfully with national commercial laboratories for referral laboratory testing for outpatients and nonpatients. In 1995, the Consortium was approached by a Rochester-based health maintenance organization (HMO) offering an exclusive contract opportunity based on requirements that included cost reduction and a switch from a fee schedule to a capitated payment method. The Rochester laboratories each agreed to contract terms with the HMO, then followed this success by working with a second, significantly larger HMO, agreeing to provide exclusive laboratory services under a similar, capitated arrangement. The formation and work of the Consortium may provide other hospitals facing daunting competition from large commercial laboratory enterprises with a cooperative arrangement model to provide community-wide laboratory services.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.