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Biomedical subjects

L P Johnson

Publications and source records attributed to L P Johnson.

At least 19 recordsLinked to original sources

Intractable epistaxis: transantral ligation vs. embolization: efficacy review and cost analysis.

After posterior nasal packing, the two most common therapies for intractable epistaxis are transantral ligation of the internal maxillary artery and percutaneous embolization of the distal internal maxillary artery. However, optimal management of intractable posterior epistaxis remains controversial. We retrospectively reviewed the charts of 21 patients treated for intractable epistaxis and obtained data on presentation, risk factors, treatment, success rates, complications, and cost. Twelve patients received percutaneous embolization, five underwent transantral ligation, and four required both. The success rates for transantral ligation and percutaneous embolization were 89% and 94%, respectively. No mortality or serious morbidity occurred with either technique. A cost comparison revealed that transantral ligation was moderately less expensive than percutaneous embolization ($5941 vs. $6783). Although some authors advocate transantral ligation or percutaneous embolization as the procedure of choice for intractable epistaxis, a direct comparison of efficacy and cost reveals that they are comparable procedures with specific strengths and weaknesses. We present our experience and a review of the literature, highlighting the indications and advantages of each technique. We conclude that the choice of treatment modality should be based on the benefits of each procedure as it pertains to the specific needs of the individual patient.

Adult

Intraoral ultrasound evaluation of peritonsillar abscess.

Peritonsillar cellulitis and peritonsillar abscess are similar clinical entities with markedly different methods of treatment. Therefore, accurate diagnosis is paramount to appropriate treatment. This pilot study was designed to evaluate the sensitivity and specificity of intraoral ultrasound as a noninvasive method of differentiating abscess from cellulitis. Sixteen consecutive patients suspected of having peritonsillar abscess were prospectively evaluated with intraoral ultrasound. The results were confirmed with imaging or surgical drainage. Correct diagnoses were made in 9 (90%) of 10 abscesses and in 5 (83%) of 6 cases of cellulitis. Our results suggest that, while there is a learning curve for intraoral ultrasound, it is an accurate, noninvasive, and inexpensive tool to differentiate abscess from cellulitis. We believe that this will be a clinically useful technique in the future.

Adolescent

Effect of hot-fat trimming on factors associated with the subprimal yield of beef carcasses.

Thirty-two crossbred cattle (steers = 17; heifers = 15) exhibiting an ultrasound fat thickness at the 12 to 13th rib region of at least 10 mm were selected from a slaughter shift at a commercial packing plant. After splitting, alternating sides of each carcass were trimmed of 1) subcutaneous fat in excess of 6.4 mm; 2) all kidney, pelvic, and heart fat; and 3) all cod or udder fat and fat in the flank region. Both sides of each carcass were fabricated into subprimals (final trim level of 6.4 mm) according to normal industry procedures. Effect of hot-fat trimming, yield grade (3, 4, and 5), and gender on hot-fat trim, fabrication fat trim, major subprimal, and total subprimal yield of untrimmed and trimmed carcasses were determined. Higher numerical yield grade (YG) corresponded with higher (P less than .05) percentages of hot-fat trim. Hot-fat trimming increased (P less than .05) the difference in fabrication fat trim between steers and heifers and between YG 3 and YG 5. Steers and heifers differed (P less than .05) in percentage of major subprimals and total subprimals when processed conventionally, whereas hot-fat trimming eliminated this difference (P less than .05). Untrimmed YG 3 carcasses had 3.1 and 5.0% higher major subprimal yield (P less than .05) than untrimmed YG 4 and YG 5 carcasses, respectively, whereas hot-fat trimming reduced this difference to 2.5% for YG 4 and to 3.7% for YG 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue

Selective management of early glottic cancer.

Seventy patients with stage I and II glottic cancer were treated at the University of Utah School of Medicine hospitals from 1980 through 1987. Forty-four patients had stage I cancer and 26 patients had stage II. The overall survival in the stage I group was 82%. Primary site control was 93% with only three deaths due to laryngeal cancer. Local control rates were 93% with CO2 laser excision, 80% with CO2 laser and irradiation, and 67% with radiation alone. Stage II glottic patients had an overall survival of 61.5% with a local control rate of 76%. Twenty-one of 24 patients were treated by full-course irradiation. Of the eight patients who recurred at the primary site, all were irradiation failures who had initial bulky disease and impaired vocal cord mobility. Selective CO2 laser excision was highly effective, whereas radiation therapy results were somewhat disappointing. Open partial laryngectomy should be considered in bulky stage II disease patients.

Adult

The prediction of percentage of protein in pork carcasses.

Determination of percentage of protein in a pork carcass is a very costly and lengthy process. Therefore, we attempted to identify an easy and economical means to predict protein content of pork carcasses. Forty-seven market-weight pigs were slaughtered. The right side of each carcass was skinned, deboned and ground for composition analysis. Carcass data were collected on the left side and specific gravity analysis was performed on the side, ham and 8-9-10 rib loin section of each carcass. The hams and loin sections were dissected into skin, bone, subcutaneous fat, seam fat and individual muscles. After these components were weighted, they were analyzed for chemical composition. Percentage of chemical protein of each animal was determined and correlated with each of the weights and measurements taken on the carcass, ham and loin sections. Stepwise regression was used to predict decimal fraction of protein using either the carcass data, specific gravity ham measurements, loin section measurements or various combinations of these. In prediction equation, specific gravity of the carcass accounted for 73.4% of the variation found in percentage of protein. Prediction equations using indicators from the ham and loin section resulted in equations with R-square values as high as .783. These results suggest that specific gravity or indicators from the carcass, ham or loin section can be employed to predict percentage of protein in pork carcasses.

Adipose Tissue

The prediction of percentage of fat in pork carcasses.

Forty-seven market-weight pigs were slaughtered in order to determine percentage of chemical fat and in an attempt to determine an easily obtainable and inexpensive method to predict this value. The hams and 8-9-10 rib loin sections were removed from the left side of each carcass and dissected into subcutaneous and seam fat, individual muscles, skin and bone. Weights and chemical analysis were determined for each component. Numerous weights, measurements and specific gravity were determined on the carcass, ham and loin section of each pig. Percentage of chemical fat of each ham, loin section and carcasses was determined and correlated with the various weights and measurements taken. Stepwise regression was used to develop prediction equations using carcass data, specific gravity, ham or loin measurements or various combinations of these as dependent variables. The single best indicator of the decimal fraction of chemical fat in the pork carcass was determined to be specific gravity of the carcass half, the prediction equation using this variable had an R-square of .64. By adding 10th rib fat thickness to this equation, the R-square increased to .72. The best equation using carcass variables included 10th rib fat and marbling (R-square = .67). The loin section proved to be an accurate indicator of composition; ham measures were not as accurate as specific gravity and carcass measurements for predicting percentage of carcass fat. This research suggests that the percentage of chemical fat in the pork carcass can be predicted by an easy and inexpensive means.

Adipose Tissue

Evolving perspectives on the exposure risks from magnetic fields.

Based on information from suggesting effects of positive and negative polarity on cancer cells, surveys were performed on magnetic resonance imaging devices, as well as other types of equipment capable of producing appreciable magnetic fields. These surveys were performed in areas where there was a potential for both occupational and general public exposure.

Electromagnetic Fields

Prognostic indicators in head and neck cancer patients receiving combined therapy.

In 1983 we initiated a prospective nonrandomized study of the value of preoperative chemotherapy in previously untreated patients with stages III and IV squamous cell carcinoma of the head and neck. In 1983 and 1984, 50 patients were entered in the study. Prior to therapy all patients were evaluated by a representative from the Medical Oncology, Radiation Therapy, and Head and Neck Surgery Divisions, University of Utah School of Medicine, Salt Lake City. In addition to the standard preoperative evaluation, pretreatment computed tomographic scans were performed on all patients. Follow-up computed tomographic scans were performed after the second cycle of chemotherapy and at the completion of treatment. Initial therapy in all patients consisted of induction chemotherapy with cisplatin (day 1, 100 mg/m2) and fluorouracil (days 1 through 5, 1000 mg/m2). Several factors were examined for their utility in predicting response to therapy and survival. Factors evaluated included: (1) extent and timing of chemotherapeutic response; (2) computed tomographic quantitated primary tumor size; (3) size of computed tomographic quantitated regional (neck) metastases; (4) performance status; (5) cancer stage; (6) total lymphocyte count; and (7) serum liver function tests. The factor found to be most useful in predicting improved survival was the extent of response to chemotherapy. The remaining factors, performance status, regional lymph node status, serum gamma-glutamyltransferase levels, and cancer stage, were also found to correlate with length of survival but were much less important than the response to chemotherapy.

Antineoplastic Combined Chemotherapy Protocols

Surgical management of isthmic spondylolisthesis.

In order to determine the factors that produce a successful outcome in the surgical management of spondylolisthesis, 44 consecutive patients who underwent surgical treatment were reviewed. Preoperative evaluation was directed towards determining the presence or absence of nerve root compression. The patients without nerve root compression typically underwent fusion alone, while those with evidence of nerve root compression had decompression and fusion. After an average 36-month follow-up, results were good in 78%, fair in 18%, and poor in 4%. There were five complications, all of which were successfully managed. Two patients required reoperation for pseudoarthrosis. An eventual 100% fusion rate was achieved. Results in the patients with Grade III or Grade IV olisthesis were nearly equivalent to the less severe cases. Nine patients received allograft, with a fusion rate equal to the 32 receiving autogenous bone. This study suggests that in patients who have isthmic spondylolisthesis with mechanical lumbar symptoms only, or in patients with low-back pain with radicular extremity pain caused by nerve root irritation, fusion alone is indicated. In patients with documented radiculopathy resulting from nerve root compression, decompression in addition to fusion is indicated.

Adolescent

Harrington-Bobechko instrumentation in the treatment of scoliosis: a preliminary report.

A dual hook system devised by Bobechko for use with Harrington and Moe distraction rods to eliminate postoperative orthotic support was employed in the surgical treatment of 57 patients with progressive scoliosis. Mean follow-up time was 33 months (range 15 to 56 months). Average correction was 51%, with an average loss of correction of 8 degrees. Five patients required reinstrumentation, two of whom had dislodgement of both upper hooks during the first postoperative week; the other three had rod breakage which occurred 3 to 20 months after surgery. The results indicate that the dual hook system provides greater security of fixation than a single hook construct, but has the disadvantage of bulkiness, making it prominent in thin patients. Postoperative protection with bracing for 6-9 months continues to be recommended to guard against instrument failure.

Adolescent

Inheritance and relationships of linear type traits for age groups of Holsteins.

Routine classifications from the linear type trait program of the Holstein Association were analyzed separately for age groups. Inheritance of linear type traits and their genetic and phenotypic relationships were evaluated. Estimates of genetic and phenotypic parameters were compared to other studies with experimental classifications from the Holstein Association and with data from artificial insemination organizations across age groups. Evaluation of sires for type traits across age groups may not properly rank sires if ages of daughters differ for sires. Future genetic evaluations of type by the Holstein Association will consider only classifications of cows closest to 30 mo, so heritabilities for linear type traits for only 2 yr olds from this study may have application. Some linear type traits are very similar genetically. Stature has substantial genetic association with final score as subjectively assigned by classifiers.

Aging

Genetic basis of secondary type traits for Holsteins.

Classifications from the Holstein Association were for secondary and primary type traits. Full linear scale of 1 to 50 was used for primary type traits, but scores for secondary type traits perceived to be midscale (21 to 29) were not recorded. Scores for midscales were randomly assigned to cows based on normalized sire distributions from percentages of daughters scored 1 to 20 and 30 to 50. Procedure for assigning scores of 21 to 29 was tested with primary type traits and judged satisfactory. Estimates of heritability for secondary type traits agreed favorably with earlier estimates. Only three secondary type traits had heritability of at least .15, and they were relative height of front end, teat placement side view, and tailhead. Heritabilities for traits of legs and feet were uniformly low, and traits of legs and feet were closely related. Little practical gain was anticipated from selection for secondary type traits.

Animals

A proposal for a combined family practice--internal medicine residency.

Both family practice and internal medicine currently train graduates for primary care. A single, four-year program is proposed that combines the strengths of family practice and internal medicine, incorporates community needs into the curriculum, and addresses the physician's changed role in a revolutionized health care provision system. Specific training recommendations and the societal and professional advantages of such a program are detailed.

Delivery of Health Care

Streptococcal pyrogenic exotoxin type A (scarlet fever toxin) is related to Staphylococcus aureus enterotoxin B.

The nucleotide sequence of the gene encoding group A streptococcal pyrogenic exotoxin type A (SPE A) was determined by the dideoxy chain termination method. The first 30 residues of the translation product represented a hydrophobic signal peptide. The mature protein was 220 amino acids in length and had a molecular weight of 25,805. It has significant protein sequence homology with Staphylococcus aureus enterotoxin B but not with other proteins in the Dayhoff library.

Amino Acid Sequence

Bacteriophage involvement in group A streptococcal pyrogenic exotoxin A production.

Lysogenic conversion has been suggested as a mechanism of control of group A streptococcal pyrogenic exotoxin type A production. Digestion of DNA from two converting bacteriophages, 3GL16 and T12, with a variety of restriction endonucleases yielded identical DNA fragments upon electrophoresis in agarose gels. Several known A toxin-positive strains that did not appear to produce converting phage upon induction were analyzed for toxin and phage DNA. Strains, including NY5, 594, and C203S, were shown by hybridization studies to carry the A toxin gene (speA) adjacent to chromosomally inserted phage fragments, homologous to phage T12 DNA, which may represent defective converting phages. The phage T12 att site mapped adjacent to speA. These data suggest that phage T12 acquired the A toxin gene from the bacterial genome. All streptococcal strains tested that were A toxin negative by Ouchterlony immunodiffusion failed to show any hybridization to speA-specific probes.

Bacterial Proteins