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Biomedical subjects

T J Prihoda

Publications and source records attributed to T J Prihoda.

At least 55 records · Page 3Linked to original sources
PubMed1990

Torch versus oven preceramic soldering of a nickel-chromium alloy.

Base metal preceramic solder joints have been described as unpredictable and inconsistent in tensile strength. Compared to base metal postoldered joints, presoldering with a gas-oxygen torch produces weaker joints that have increased porosity and voids. This investigation compared the tensile strength of base metal solder joints presoldered with a gas-oxygen torch to that of joints presoldered in a porcelain oven under vacuum. The mean (+/- SD) solder joint tensile strength was 460.0 (+/- 99.4) MPa for the oven-soldered and 520.2 (+/- 37.8) MPa for the torch-soldered specimens. A strong, consistent, void-free preceramic solder joint was produced between a nickel-chromium base and gold solder by both torch- and oven-presoldering techniques; however, preceramic soldering with a torch tended to result in a stronger bond.

Ceramics↗
PubMed1990

Hospital-based toxicology: patterns of use and abuse.

We examined 949 consecutive toxicology requests to determine (a) the identity and relative frequency of the most commonly detected drugs in our hospital population; (b) degree of concordance between clinical impression and laboratory analysis; (c) influence of age and sex upon the numbers and results of toxicologic analyses; (d) temporal pattern of our annual toxicology case-load; (e) temporal and sexual distribution of various common drugs; (f) drugs most often found together; and (g) frequency with which inappropriate toxicology request were received. Laboratory analysis agreed with clinical impression in only 17.4% of cases. Age and sex correlated with the detection of specific drugs. But for benzodiazepines, no consistent temporal pattern was present regarding either type or number of drugs detected. Certain days of the week demonstrated a statistically significant effect upon the number of toxicology requests received, while seasons, holidays, and lunar phases had no influence. Inappropriate requests comprised 9% of the total annual toxicology caseload.

Adolescent↗
PubMed1990

A clinical and microbiologic analysis of risk factors for puerperal endometritis.

Predictors of postpartum endometritis were identified in 607 asymptomatic, laboring women. One hundred (16.5%) developed postpartum endometritis. Multivariate analysis using stepwise logistic regression identified cesarean delivery (relative risk 12.8; P less than .0001) as the dominant overall predictor. In patients with cesarean delivery (N = 124), prophylactic antibiotics (relative risk 0.54; P less than .0002) and high-virulence bacteria or Mycoplasma hominis (relative risk 1.4; P less than .01) predicted the incidence of endometritis, and in patients with vaginal delivery (N = 483), "bacterial vaginosis organisms" (relative risk 14.2; P less than .001) and aerobic gram-negative rods (relative risk 4.2; P less than .01) predicted endometritis. Despite significant associations found on univariate analysis, clinical variables such as duration of labor, rupture of membranes, and internal monitoring were not predictive of endometritis in the multivariate analysis. Our findings show that cesarean delivery and certain organisms, such as bacterial vaginosis or high-virulence organisms, predict endometritis, and that clinical variables may be facilitators rather than predictors of endometritis.

Adult↗
PubMed1989

Development and initial validation of a dual-language English-Spanish format for the Arthritis Impact Measurement Scales.

Language, cultural, and educational barriers complicate efforts to validate health status questionnaires that have been translated into Spanish. To overcome these problems, a prototype dual-language format was developed for the Arthritis Impact Measurement Scales. Validity testing with 72 patients diagnosed as having rheumatoid arthritis indicated high levels of test-retest reliability, item-to-scale internal consistency, and construct validity for both Anglo and Hispanic subjects. A technique for developing and pilot-testing a questionnaire written in a regional Spanish dialect is described. Linguistic considerations, questionnaire design, and other applications are discussed in light of the results obtained.

Arthritis↗
PubMed1989

Plaque fluid pH, calcium and phosphorus responses to calcium food additives in a chewable candy.

Fourteen subjects between 7 and 17 years of age with an equal distribution of low and high caries activity were given: (1) a 10% sucrose rinse, (2) a reference candy, (3) a reference candy with 3% dicalcium phosphate dihydrate, and (4) a reference candy with 0.75% calcium lactate on four different occasions. Plaque samples were collected before and at 15-min intervals after the sucrose rinse or food challenge for a period of 1 h on each occasion. Plaque samples were centrifuged and the extracellular plaque fluid analysed by a microtechnique for pH, total calcium and inorganic phosphorus concentration. There was no significant increase in calcium and phosphorus in plaque fluid for the group using candy with added calcium compared to the reference candy or sucrose rinse. There was no significant difference between the measurements in subjects grouped as caries active or inactive. The results suggest no benefit can be expected from adding dicalcium phosphate dihydrate and calcium lactate to candy to decrease demineralization during a cariogenic challenge.

Adolescent↗
PubMed1989

An approach to developing a valid Spanish language translation of a health-status questionnaire.

This article discusses methodological issues confronting health professionals using questionnaires to study health care variables among populations with limited literacy in English, and suggests techniques for minimizing problems that plague questionnaire-based research among these populations. A recent effort to validate a questionnaire for Rheumatoid Arthritis patients in South Texas is used to illustrate pitfalls and potential solutions.

Arthritis, Rheumatoid↗
PubMed1989

O2- and pneumonia-induced lung injury. I. Pathological and morphometric studies.

The physiological, morphological, and morphometric findings of several lung injury models in baboons have been compared in the following six study groups: 1) initial injury with oleic acid followed by ventilation with 100% O2, 2) ventilation with 100% O2, 3) ventilation with 80% O2, 4) ventilation with 80% O2 followed by inoculation of Pseudomonas aeruginosa, 5) ventilation with 40% O2, and 6) normal nonventilated room-air-breathing animals. The animals were maintained for 11 days in an intensive care unit. Light microscopically, animals ventilated with 40 and 80% O2 showed mild lung injury, consisting mostly of an increase in alveolar macrophages in peribronchiolar sites and focal alveolar wall widening. The 100% O2-oleic acid, 100% O2, and 80% O2-Pseudomonas-treated baboons showed mixed exudative-reparative diffuse alveolar lesions. Ultrastructurally, the type II cells of these three groups had significantly altered morphology with aberrations of lamellar body configurations. Morphometric findings showed increases in type II and interstitial cells and decreases in type I and endothelial cells in these injured animals. A striking finding was that the physiological, morphological, and morphometric changes of an 80% O2-Pseudomonas insult was as injurious as 100% O2. This synergistic effect of hyperoxia and infection very likely reflects the most frequent evolution of adult respiratory distress syndrome in patients in intensive care units.

Animals↗
PubMed1989

Clinical determinants of abnormalities in pulmonary functions in survivors of the adult respiratory distress syndrome.

Pulmonary function tests (PFTs) were performed in 39 survivors of the adult respiratory distress syndrome (ARDS) in whom clinical data had been prospectively collected during the acute episode. PFTs stabilized within 6 months of the episode and had returned to normal in most survivors. Persistent abnormalities were found after 6 months in diffusing capacity (14 of 23 patients, 61%), vital capacity (10 of 23 patients, 43%), and total lung capacity (five of 24 patients, 21%). To clarify the mechanisms underlying these persistent abnormalities, we attempted to correlate long-term PFT outcomes with estimates of the severity of initial lung injury as assessed from clinical data and with other features of the patient's course. The severity of lung function impairment during the first 3 days of ARDS was not related to long-term PFT values. However, a lower DLCO was related to a higher AaDO2, higher pulmonary artery pressure, and worse radiographic appearance on Days 4 through 7 and to the occurrence of sepsis. A lower FVC was related to higher pulmonary vascular resistance in Days 4 through 7 of ARDS. Long-term values for FVC and TLC were directly related to increasing levels of PEEP applied from Days 4 through 7 of ARDS in patients with peak airway pressures less than 50 cm H2O. Long-term abnormalities of pulmonary function of survivors of ARDS were not related to initial lung impairment but were directly related to persistence of impaired lung function during the acute episode. Recovery of lung function may also have been directly related to therapeutic modalities such as PEEP and impaired by the occurrence of sepsis.

Adolescent↗
PubMed1989

Chronic secretory otitis media: effects of surgical management.

To study the effectiveness of adenoidectomy and tympanostomy tubes in the treatment of chronic otitis media with effusion, we randomly assigned 578 4- to 8-year-old children to receive one of the following: bilateral myringotomy and no additional treatment (group 1), tympanostomy tubes (group 2), adenoidectomy and myringotomy (group 3), or adenoidectomy and tympanostomy tubes (group 4). The 491 who accepted surgical treatment were evaluated at 6-week intervals for up to 2 years. Treatment effect was assessed by four main outcomes: time with effusion, time with hearing loss, time to first recurrence of effusion, and number of surgical re-treatments. For the groups (in order), the mean percent of time with any effusion in either ear was 49, 35, 30, 26 (p less than .0001); the mean percent of time with hearing thresholds 20 dB or greater was 19, 10, 8, and 7 (p less than .0001) in the better ear; and 38, 30, 22 and 22 in the worse ear (p less than .0001); the median number of days to first recurrence was 54, 222, 92, and 240 (p less than .0001); and the number of surgical re-treatments was 66, 36, 17, and 17 (p less than .0001). The most notable adverse sequela, purulent otorrhea, occurred in 22%, 29%, 11%, and 24% of the patients assigned to groups 1 through 4, respectively (p less than .001). In severely affected children who have chronic otitis media with effusion resistant to medical therapy, adenoidectomy is an effective treatment. Adenoidectomy plus bilateral myringotomy lowered posttreatment morbidity more than tympanostomy tubes alone and to the same degree as did adenoidectomy and tympanostomy tubes. Adenoidectomy appears to modify the underlying pathophysiology of chronic otitis media with effusion. This effect is independent of the preoperative size of the adenoid. Tympanostomy tube drainage and ventilation of the middle ear provide adequate palliation so long as the tubes remain in place and functioning. We recommend that adenoidectomy be considered in the initial surgical management of 4- to 8-year-old children with hearing loss due to chronic secretory otitis media that is refractory to medical management and, further, that the size of the adenoid not be used as a criterion for adenoidectomy. Concomitant bilateral myringotomy with suction aspiration of the middle ear contents also should be done, with or without placement of tympanostomy tubes at the discretion of the surgeon.

Acoustic Impedance Tests↗
PubMed1989

An objective method of compliance assessment with metered-dose inhalers.

Evaluation of compliance with metered-dose inhalers (MDIs) is especially difficult. We investigated the correlation between serial weight change of the MDI canister and the number of doses delivered. Canister weight strongly correlated with number of activations for three different bronchodilators (metaproterenol, r2 = 0.9965; albuterol, r2 = 0.9984; terbutaline, r2 = 0.9913). To validate these results, a one-month trial designed to mimic patient use was conducted. Nine aerosol bronchodilator MDIs (three each of terbutaline, albuterol, and metaproterenol) were evaluated by three volunteers, each given one of each type of MDI. Number of activations were recorded in a diary and canisters were weighed weekly. At the end of the four-week period the number of activations were determined from weekly canister weight. Predicted activation numbers, calculated from both regression line and baseline weight, were compared to actual activation number. Statistical analysis was done using analysis of variance. Predicted number of activations for all three drugs ranged from 77 to 125 percent of observed and did not significantly differ depending on the type of bronchodilator (p = 0.3340). The method of prediction, regression intercept or baseline weight, led to significantly different predictions (p = 0.0569). The interaction between the method of prediction and type of bronchodilator was significant (p = 0.0197). Using either method, the actual number of doses dispensed can be predicted within 25 percent.

Albuterol↗
PubMed1989

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions.

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Brain Concussion↗
PubMed1989

Logistic regression analysis of risk factors for intra-amniotic infection.

The identification of risk factors for intra-amniotic infection may allow changes in obstetric management and reduce complications. In a pilot study, stepwise logistic regression identified duration of ruptured membranes and duration of interval monitoring as significant risk factors for intra-amniotic infection. Using the preliminary regression equation, we established critical durations (risk criteria) to predict a 20% or greater probability of intra-amniotic infection. Subsequently, 2908 patients were screened prospectively for risk criteria and/or the presence of intra-amniotic infection. Seven hundred five patients of the 2908 (24%) met the risk criteria, and 107 of 124 cases of intra-amniotic infection (86%) met the risk criteria. In patients meeting the risk criteria, the relative risk of intra-amniotic infection was 19.7. In addition, 81 of 705 (12%) of mothers developed endometritis. Ten neonates of mothers with criteria developed sepsis or pneumonia. A stepwise logistic regression performed on the prospectively gathered data showed that among patients meeting risk criteria, parity, duration of internal monitoring, and duration of membrane rupture were the significant risk factors for intra-amniotic infection.

Adult↗
PubMed1988

Antigliadin antibodies detected by enzyme-linked immunosorbent assay as a marker of childhood celiac disease.

Using an enzyme-linked immunosorbent assay (ELISA) assay, we studied the sera of 17 patients with celiac disease and 114 control subjects for the levels of IgG and IgA antigliadin antibodies. As a group, the patients with celiac disease had significantly higher levels of antigliadin antibodies of both IgG and IgA classes (p less than or equal to 0.001). However, there was a significant overlap of values, resulting in respective sensitivities and specificities of 88% and 90% for IgG antigliadin antibodies, and 73% and 65% for IgA antigliadin antibodies. The combined use of both IgG and IgA antigliadin antibody levels produced a sensitivity of 86% and a specificity of 90%. A gluten-free diet in celiac patients did not seem to affect these results. We conclude that the antigliadin antibody ELISA assay cannot be used as a definitive diagnostic test for celiac disease. The small-bowel biopsy remains the principal diagnostic method; the ELISA assay should, at best, be considered a screening test for this disease.

Antibodies↗
PubMed1988

Delayed onset post-tympanotomy otorrhea.

Otorrhea is the most frequent complication of the use of tympanostomy tubes. When it occurs after the immediate postoperative period, otorrhea is probably the result of external contamination of the middle ear or acute otitis media. We analyzed data from 627 operations upon 1248 ears of 491 children with chronic secretory otitis media and found that delayed onset (longer than 7 weeks) postoperative otorrhea occurred after 26.4 percent of the 382 operations in which tympanostomy tubes were used. The average number of episodes of otorrhea per case was 1.46 and ranged from 1 to 9. The rate of otorrhea occurrence in patients with tubes in place was significantly higher in the summer months. Otorrhea also occurred after 9.0 percent of 245 myringotomy procedures. The average number of episodes was 1.32 and ranged from 1 to 3. Treatment of postoperative otorrhea increases the health care costs of surgical treatment of chronic otitis media with effusion; this problem should be included in the calculation of cost-effectiveness.

Child↗
PubMed1988

Diffuse alveolar damage in the evolution of bronchopulmonary dysplasia in the baboon.

Pulmonary immaturity, oxygen exposure that elicits cellular damage by free radicals, and barotrauma induced by mechanical ventilation are implicated in the pathogenesis of bronchopulmonary dysplasia. In the adult counterpart of adult respiratory distress syndrome, diffuse alveolar damage characterizes a histopathological sequence of lung findings that can occur during the disease course. Although adult respiratory distress syndrome has many etiologies, elevated oxygen exposure is known to be a contributor to the ensuing lung injury. In bronchopulmonary dysplasia, oxygen exposure is thought to be a primary agent of injury. The evolution of the histopathological findings in the premature baboon model of hyaline membrane disease/bronchopulmonary dysplasia was investigated in this study and compared to that in oxygen-treated adult baboons with adult respiratory distress syndrome. Findings from lung specimens of 121 prematurely delivered baboons at 0, 0.5, 1, 2, 3-6, 7-11+ days after delivery document that the premature lung has a delayed and more blunted exudative response when compared to that of human and baboon adults. Saccular edema, not hyaline membranes, is the dominant histopathological finding in the exudative phase of diffuse alveolar damage and occurs later (7-11 days) in infant lungs when compared to comparably treated adult lungs in which maximal exudative changes are seen at 3-6 days. The reparative response in the premature baboon is characterized by saccular wall thickening and fibrosis, with less intramural organization of exudate in saccular/alveolar spaces when compared to adults. The airway changes in the premature are more severe than those seen in adult disease. These findings indicate that diffuse alveolar damage does occur in the immature lung albeit with differing characteristics when contrasted to comparably injured adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effect of adenoidectomy upon children with chronic otitis media with effusion.

To investigate the mechanism whereby adenoidectomy influences the subsequent course of patients with chronic otitis media with effusion, we analyzed, on the basis of adenoid size, the outcomes of 476 children randomly assigned to receive, after paracentesis and aspiration of the middle ear, either no treatment, tympanostomy tubes, adenoidectomy, or both. The two groups receiving adenoidectomy did significantly better than those who did not, and the effect was independent of adenoid size. This suggests that reduction of the adenoidal bacterial reservoir may be the mechanism whereby adenoidectomy is effective.

Adenoidectomy↗
PubMed1988

Creatine kinase MB in cases of skeletal muscle trauma.

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.

Craniocerebral Trauma↗