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Biomedical subjects

E Larsen

Publications and source records attributed to E Larsen.

At least 73 records · Page 4Linked to original sources
PubMed1990

Effects of peripheral administration of naloxone on beta-adrenergic mediated responses.

A possible interaction between the opiate and beta-adrenergic systems in controlling body temperature, heart rate and water intake was investigated using adult male Sprague-Dawley rats. Peripheral administration of isoproterenol (8 and 50 micrograms/kg, s.c.) produced significant elevations of heart rate and tail skin and colonic temperatures, respectively. Peripheral pretreatment with naloxone (1 mg/kg, s.c.) was without effect on these beta-adrenergic responses. Administration of isoproterenol (25 micrograms/kg, s.c.) produced a significant increase in water intake which was abolished by peripheral pretreatment with naloxone (1 mg/kg, s.c.). Previous studies have suggested that the dipsogenic response to isoproterenol is mediated through angiotensin II. In the present study the angiotensin II-induced (200 micrograms/kg, s.c.) dipsogenic response was abolished by naloxone pretreatment. However, pretreatment with an equimolar dose of naloxone methobromide, an opiate antagonist which does not cross the blood-brain barrier, was ineffective in altering the dipsogenic response produced by peripheral administration of either angiotensin II or isoproterenol. Collectively, the data suggest that opiates do not alter peripheral beta-adrenergic responses and that the blocking effects of naloxone on the isoproterenol-induced drinking response is mediated centrally and may be due to blocking angiotensin II dipsogenesis.

Angiotensin II↗
PubMed1990

Association of ankle instability and foot deformity.

95 patients operated on for chronic lateral ankle instability were compared for possible foot deformities with 34 normal persons. All the feet underwent a standardized radiographic examination. Measurements of three defined angles on a lateral nonweight-bearing radiograph indicated higher foot arches in the instability group than in the control group. Benink's tarsal index showed a higher frequency of cavovarus deformities in the instability group.

Adolescent↗
PubMed1990

Alterations in the longevity and fecundity of adult Trichinella pseudospiralis related to method of isolation of infective larvae.

The infectivity of Trichinella pseudospiralis infective larvae was reduced significantly following exposure to low pH or a combination of 1% pepsin at low pH compared to that for larvae isolated in phosphate-buffered saline (PBS) at pH 7.0. Reduction of host gastric pH by administration to mice of sodium bicarbonate solution in PBS was accompanied by an increase in the infectivity of larvae isolated in 1% pepsin/HCl (P/HCl) compared to that for worms inoculated into hosts given PBS alone. Fewer adult worms developing from larvae isolated in P/HCl became established in the host small bowel than was seen with larvae isolated in PBS; moreover, the fecundity in vitro of adult worms developing from P/HCl-isolated larvae was reduced below that for adults developing from larvae isolated from host muscle in PBS. More adult worms were recovered following infection of immune hosts with PBS-isolated larvae than were recovered from immune mice challenged with larvae isolated in P/HCl. Similar findings were observed in mice immunized by infection with Trichinella spiralis and challenged with T. pseudospiralis larvae isolated in either P/HCl or PBS. Immunization of mice with T. pseudospiralis larvae isolated by either method and challenged with larvae of T. spiralis resulted in recovery of similar percentages of the challenge inoculum.

Animals↗
PubMed1990

Infectivity of Trichinella pseudospiralis isolated from carrion.

The reproductive capacity index for Trichinella pseudospiralis infective larvae was similar for worms isolated from mouse carcasses on the day upon which mice were killed (day 0: 104.4 +/- 18.6 [mean +/- SD]) and on day 5 following mouse death (106.1 +/- 23.6), but was reduced for worms recovered from carcasses on day 10 postkill (PK: 22.7 +/- 5.7). Larvae isolated from mouse carcasses held at 24 C after day 10 PK were not infective. The percentage of viable worms (tightly coiled or moving) isolated from carrion was similar on days 0 and 5 PK but had declined to 40.4% by day 10 PK and showed a further reduction to 11.8% for worms isolated from carrion on day 15 PK. Viable worms were not recovered from carcasses after day 15 PK.

Animals↗
PubMed1990

Static or dynamic repair of chronic lateral ankle instability. A prospective randomized study.

In a prospective study, 82 patients with 89 chronic lateral unstable ankles were randomly allocated to either static (Group S) or dynamic (Group D) reconstruction. For static reconstruction a procedure involving the distal part of the peroneus brevis tendon was used. The bore holes in the lateral malleolus were placed at the insertions of the original ligaments. For dynamic reconstruction the anterior one-half of the peroneus brevis tendon was used. On muscular contraction the split tendon will slide through a bore canal in the lateral malleolus. Theoretically, both procedures can stabilize the ankle and subtalar joint. Fifty-six patients were assigned to static reconstruction and, because of thin tendons, only 26 were assigned to dynamic reconstruction. Thirty-three cases had increased subtalar mobility. All patients had standardized clinical and roentgenographic examinations preoperatively and at nine and 25 months postoperatively. At the 25-month follow-up examinations the clinical results were best in Group S. The number of reinjuries was highest in Group D, and two patients had given up sports. The inversion movement was most restricted in Group S but without functional importance. A significant reduction of talar tilting and anterorotational talar displacement was seen in both groups but was most pronounced in Group S. Also, postural balance improved in both groups. Complications in Group S were venous thrombosis in two patients, dysesthesia in the cicatrix in two, hyposensibility of the lateral foot edge in one, and calcification at one bore hole in one patient. Complications in Group D were hyposensibility and dysesthesia in the cicatrix in one patient. The static procedure is recommended for reconstruction of chronically unstable ankles, especially if associated with increased subtalar mobility.

Adolescent↗
PubMed1989

PADGEM protein: a receptor that mediates the interaction of activated platelets with neutrophils and monocytes.

PADGEM (platelet activation dependent granule-external membrane protein) is an integral membrane protein of the alpha granules of platelets and Weibel-Palade bodies of endothelial cells that is expressed on the plasma membrane upon cell activation and granule secretion. Activated platelets, but not resting platelets, bind to neutrophils, monocytes, HL60 cells, and U937 cells. This interaction is inhibited by anti-PADGEM antibodies, PADGEM, and EDTA; anti-GPIIb-IIIa, anti-thrombospondin, anti-GPIV, and thrombospondin produce no effect. Neutrophils and U937 cells, in contrast to Jurkatt cells, contain PADGEM recognition sites, as shown by binding of PADGEM contained in phospholipid vesicles. These results indicate that PADGEM mediates adhesion of activated platelets to monocytes and neutrophils. Therefore, PADGEM shares not only structural but also functional homology with ELAM-1 and MEL-14, members of a new family of vascular cell adhesion molecules.

Antibodies, Monoclonal↗
PubMed1989

Genetic analysis of modifiers affecting sexual dimorphism and temperature sensitivity of bx1 in Drosophila melanogaster.

Two modifiers of bithorax1 phenotypic expression are described. An X-chromosome region is associated with sexual dimorphism in bx1 penetrance. It is hypothesized that sexual dimorphism is in part due to a lack of dosage compensation of the modifier, in males. A third chromosome region that segregates with the pink peach allele is implicated in mediating temperature sensitivity. By appropriate combinations of modifiers, both sexual dimorphism and temperature sensitivity can be greatly reduced.

Alleles↗
PubMed1989

The HPC-device: a method to quantify the heel pad shock absorbency.

Previous studies have indicated that the shock absorbency of the heel pad is significant in the pathophysiology of pain conditions connected with heel strike. The purpose of this study was to develop a simple clinically usable method for quantification of the heel pad shock absorbency. The results of our efforts was the HPC-device which consists of a fixing device and a transducer. The HPC-device was found suitable in the evaluation of the heel pad force/deformation characteristics. The reproducibility of heel pad deformation was 0.96. Tests of six cadaver heel pads revealed a high correlation between the HPC result and the shock absorbency found by drop tests. In a normal material (200 heel pads), it was found that the shock absorption decreased with age and that men had significantly higher shock absorbency than women. Men also had significantly thicker heel pads than women. However, there was no linear correlation between the thickness of the heel pad and the shock absorbency, although the thinnest heel pads had the lowest shock absorbency. The HPC-device was found clinically usable and will be used in further testing of the significance of heel pad shock absorption for the development of heel strike dependent over-use injuries.

Adolescent↗
PubMed1989

Synovitis in chronically unstable ankles.

Histopathologic synovial changes were studied prospectively in 69 patients with 75 ankles operated on for radiographically verified chronic lateral instability. The median duration of instability was 2(0.5-20) years. Before the operation, 73 ankles were painful. After a peroneus brevis tenodesis, all but 1 patient felt improved. Twenty-eight of 75 ankles had moderate or extreme degrees of synovitis. The degree of ankle instability did not influence the severity of changes. Factors that influenced the degree of synovitis were duration of instability of more than 4 years, degenerative changes--such as old bony avulsions, chondral fibrillations and clefts--and high activity level of the patient. To improve stability, alleviate pain, and perhaps to prevent the development of arthrosis, we recommend ligamentous repair in painful active patients with long-standing lateral instability of the ankle with degenerative changes in or around the ankle joint.

Adolescent↗
PubMed1989

Infection of the Chinese hamster with Trichinella pseudospiralis.

A mean of 2,862 muscle larvae was recovered on day 45 postinfection (PI) from the total body musculature of Chinese hamsters infected with 498 Trichinella pseudospiralis. Infection of the Chinese hamster with 494 Trichinella spiralis resulted in recovery of a mean of 225 muscle larvae on day 45 PI. The reproductive capacity index for T. pseudospiralis was 5.74, whereas that for T. spiralis was 0.46 in this host species.

Animals↗
PubMed1988

Mass spectrometry of underivatized 15-hydroxyeicosatetraenoic acid and 15-hydroxyeicosapentaenoic acid.

A direct mass spectrometric method for 15-hydroxy metabolites of arachidonic acid and of eicosapentaenoic acid is described. 15-Hydroxyeicosanoids have the capacity to inhibit the formation of leukotrienes, potent mediators of inflammation formed by the 5-lipoxygenase pathway of arachidonic acid metabolism and may therefore have anti-inflammatory properties. 15-Hydroxyeicosatetraenoic acid (15-HETE) and 15-hydroxyeicosapentaenoic acid (15-HEPE) were synthesized using soybean lipoxygenase and arachidonic acid and eicosapentaenoic acid as substrates. These hydroxy fatty acids were then purified by reversed-phase high-performance liquid chromatography. This modified procedure provides rapid synthesis of multimilligram quantities of 15-hydroxyeicosanoids for in vitro and in vivo studies. Electron impact mass spectra of 15-HETE and 15-HEPE could be obtained directly without derivatizations.

Chromatography, High Pressure Liquid↗
PubMed1988

Patterns of cell division in imaginal discs of Drosophila.

A transmission electron microscopic study of cell division in serially sectioned imaginal discs of early third instar fruitfly larvae revealed that mitotic cells maintain a relationship with the basal surface of the disc through thin cytoplasmic extensions abutting on vesicular material. Two patterns of cell division were discerned. In one, cell divisions were isolated and usually found near the peripodial membrane-disc epithelium junction; in the other, cell divisions were clustered. Observations on cell death and cell division in the peripodial membrane are also reported.

Animals↗
PubMed1988

Purpuric contact dermatitis from black rubber chemicals.

Black rubber chemicals are capable of causing an allergic contact dermatitis, in some cases associated with a purpuric capillaritis. A typical case of such a purpuric reaction is described in a man sensitive to black rubber chemicals.

Aged↗
PubMed1988

Femoral shaft fracture after hip arthroplasty.

Femoral shaft fractures after hip arthroplasties were treated in 74 noncemented hemiarthroplasties and 65 cemented arthroplasties. In loose prostheses the best clinical results and the least number of operations were achieved with revision arthroplasty with a long-stem prosthesis, combined with simple internal fixation methods when applicable. In firmly fixed prostheses the results of revision arthroplasty and traction treatment were similar. Cemented revision arthroplasty did not interfere with fracture union. Internal fixation with the prosthesis in situ cannot be recommended because of a large number of secondary revision arthroplasties and nonunions. Removal of the femoral stem prosthesis and internal fixation nearly always require a secondary revision and cannot be recommended.

Adult↗
PubMed1988

Remodeling of angulated distal forearm fractures in children.

Seventy children treated for distal forearm fractures were clinically and roentgenologically reexamined with a median follow-up time of 3.5 years (range, 1.5-6.0 years). The angulation of the fractures and of the epiphyseal plates was measured at the time of healing and at the follow-up examination. The patients were divided into three age groups of 0-5 years, 6-10 years, and 11-15 years at the time of fracture. In children younger than 11 years of age with residual angulation after distal forearm fractures, the change of orientation of the epiphyseal plate toward normal seemed to account for nearly all the actual correction at the site of fracture, up to 28 degrees. In children older than 11 years of age the capacity of correction of the orientation of the epiphyseal plate was preserved, but its influence upon the correction of distal forearm fractures decreased. This did not prevent correction of possible residual angulation at the fracture site--up to 18 degrees. This may be because, in this age group, appositional bone formation and resorption are the most important remodeling factors. The importance of the orientation of the epiphyseal plate is related to the distance between the fracture site and the epiphyseal plate and by the age of the patient.

Adolescent↗
PubMed1988

Metastasis size in pathologic femoral fractures.

Radiographic assessment was made of metastases in 69 consecutive patients with pathologic femoral fractures. The following variables were considered: width of metastasis, ratio between width of metastasis and bone, axial length of cortical destruction, and proportion of cortical bone destroyed of the circumference. Differences in size of the metastases were not related to location in the femur or histologic type. In 62 of 69 fractures the ratio between width of the metastasis and bone was greater than or equal to 0.60, axial cortical destruction in the neck was greater than or equal to 13 mm and in other parts of the femur greater than or equal to 30 mm, and cortical destruction of the circumference greater than or equal to 50 percent. Prophylactic internal fixation need not be considered for femur metastatic lesions that do not reach these limits.

Adult↗
PubMed1988

Tendon transfer for lateral ankle and subtalar joint instability.

Seventy-three patients suffering from lateral instability of the ankle joint, bilateral in 6 cases and combined with subtalar instability in 25, were operated on using the distal part of the peroneus brevis tendon. The tendon was pulled through two bore canals in the lateral malleolus and fixed in a bore hole in the calcaneus. The direction of the tendon in relation to the calcaneus and the talus was varied depending upon the type of instability. At 9 and 24 months follow-up, all but 2 patients had substantial reduction of the radiographically measured instability. No subtalar instability could be disclosed, and all the patients could return to normal levels of activity. The operation can be recommended for chronic lateral ankle and subtalar joint instability.

Adolescent↗