Biomedical subjects

M A Schork

Publications and source records attributed to M A Schork.

At least 19 recordsLinked to original sources

PubMed1995

Hemodynamic characteristics of neonates following first stage palliation for hypoplastic left heart syndrome.

BACKGROUND: It is widely held that the postoperative course of patients with hypoplastic left heart syndrome (HLHS) after stage 1 palliation is characterized by hemodynamic instability, which in part may be due to excessive pulmonary blood flow. Hence, avoidance of alkalosis and the use of minimally oxygen-enriched inspiratory gas are thought by many to be important, although there is little pertinent published data. This study was undertaken to characterize the postoperative course and to determine whether the FIO2 and blood pH are related to indices of hemodynamic stability in these infants. METHODS AND RESULTS: The postoperative course of 25 consecutive infants undergoing first stage palliation for HLHS were retrospectively reviewed and the following data were obtained: arterial pressure, arterial blood gas measurements, the inotropic agents used, and multiple respiratory parameters. There was one operative death, and 2 patients died within 2 days, but 22 were extubated (mean, 5.2 +/- 4.1 days after surgery). Hospital mortality was 24%. Mean pH was > or = 7.51 for the first 9 hours after surgery and was > or = 7.45 for the entire period. The mean FIO2 was > or = 50% for the first 18 hours. The PaO2 was appropriate (37 +/- 6 mm Hg at 1 hour after surgery, increasing to 45 +/- 5 mm Hg by hour 73). Only modest inotropic support was needed to maintain appropriate blood pressure. CONCLUSIONS: These data suggest that neither alkalosis nor relatively high inspired oxygen necessarily cause hemodynamic instability in these patients. To what extent these results are generalizable is unclear, but they suggest that there is nothing inherent with HLHS that mandates postoperative hemodynamic instability or unacceptable mortality.

Arteries↗

PubMed1995

A study of radiologic imaging techniques and airway grading to predict a difficult endotracheal intubation.

STUDY OBJECTIVES: To study whether a detailed radiographic examination of neck and upper airway can help identify normal looking patients in whom endotracheal intubation may be difficult; determine whether such parameters as identified by magnetic resonance imaging (MRI) can also be identified in a soft tissue radiograph; and to study the correlation between oropharyngeal appearance, based on Mallampati's classification, and laryngoscopic findings in a large number of patients requiring endotracheal intubation. DESIGN: Prospective. SETTING: University medical center. PATIENTS: 20 adult patients in whom an unanticipated difficult endotracheal intubation was encountered, and a control group of 20 patients in whom endotracheal intubation was easily accomplished. INTERVENTIONS: Difficult-to-intubate patients were identified according to prospectively established criteria. Control subjects, in whom the trachea was easily intubated, were matched for age, gender, height, weight, and oropharyngeal appearance. MEASUREMENTS AND MAIN RESULTS: In all 40 study patients, a soft tissue radiograph and an MRI scan of the neck were obtained. We measured 21 parameters from both radiographic studies. There were no significant differences between the two groups in 20 of 21 measured parameters on MRI scans and soft tissue radiographs. Only one measurement--the distance between the uppermost visible part of the airway and the posterior pharyngeal wall (measured from MRI scans only)--between the two groups achieved statistical significance. The values recorded from MRI and soft tissue radiographs were not significantly different. Airway grading system first suggested by Mallampati had a fair correlation with laryngoscopy findings associated with a difficult endotracheal intubation. CONCLUSIONS: No significant difference between the two groups could be identified on soft tissue radiography or MRI scans.

Adult↗

PubMed1995

Visual outcome and ocular survival after penetrating trauma. A clinicopathologic study.

PURPOSE: Ocular trauma is a leading cause of blindness in the United States. This study was undertaken to identify clinical and histopathologic factors that predict ocular survival and final visual acuity after penetrating ocular trauma. METHODS: One hundred seventy-six cases of ruptured globe were reviewed. Factors analyzed included (1) initial visual acuity, (2) wound location, (3) wound length, (4) mechanism of injury (sharp, blunt, or missile), (5) presence of intraocular foreign body, (6) type of ocular wound (perforating versus nonperforating), (7) performance of vitrectomy, and (8) histopathologic features (n = 40). Data were analyzed using univariate and multivariate logistic regression analysis. RESULTS: Predictors of excellent final visual acuity (20/60 or better) were initial visual acuity of 20/200 or better, wound location anterior to the plane of insertion of the four rectus muscles, wound length 10 mm or less, and sharp mechanism of injury. In contrast, predictors of poor vision were initial visual acuity of light perception or no light perception, wounds extending posterior to rectus muscle insertion plane, would length greater than 10 mm, and blunt or missile injury. Vitrectomy did not improve final vision. Factors predicting enucleation were similar to those predicting poor vision; however, vitrectomy decreased the likelihood of enucleation. Histopathologic review showed fibrous ingrowth in 93% of eyes enucleated more than 14 days after injury, and none of those enucleated within 2 weeks. CONCLUSION: Significant predictive factors of final visual acuity after penetrating trauma include visual acuity, wound location and length, and mechanism of injury. Establishment of predictors of ocular survival and visual function may assist clinicians in selecting salvageable eyes for surgical repair.

Adolescent↗

PubMed1995

Are traditional prognostic criteria useful in pancreatic abscess?

Pancreatic abscess remains a potentially lethal disease. Efforts to relate outcome to the severity of associated pancreatitis or the type of surgical drainage employed have yielded conflicting results. This study was designed to test the validity of traditional prognostic criteria in the clinical setting of pancreatic abscess and to determine whether the technique of surgical drainage employed correlated with survival. The records of 40 consecutive patients with pancreatic abscess were reviewed. In each case the diagnosis was confirmed by operation. Prognostic factors analyzed included number of Ranson criteria, etiology, type, and number of microorganisms isolated, extent of abscess, time to diagnosis and operation, and technique of surgical drainage. Of the 11 Ranson criteria evaluated, only an elevation in blood urea nitrogen > 5 mg/dl correlated with decreased survival (p < 0.001). Polymicrobial abscesses (three or more organisms) resulted in a higher mortality than abscesses where fewer than three organisms were isolated (45.4 vs 13.8%; p < 0.05). Intraperitoneal extension of the abscess was associated with an increased mortality rate compared to those confined to the retroperitoneum (57.1 vs 15.2%; p < 0.01). In patients requiring unplanned reexploration, mortality was significantly increased (42.9 vs 11.5%; p < 0.05). The technique of surgical drainage employed (open versus closed) did not influence overall mortality (23.5 vs 21.7%; p = NS). Extent of disease at operation, polymicrobial abscess, reexploration for persistent or recurrent disease, and deterioration in renal function were all predictive of increased mortality in cases of pancreatic abscess.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗

PubMed1995

Variability in Cobb angle measurements in children with congenital scoliosis.

The variability in measurement of angles in congenital scoliosis is not known, but it is postulated that it is larger than that in adolescent idiopathic scoliosis due to skeletal immaturity, incomplete ossification, and anomalous development of the end-vertebrae. To determine this variability, we selected 54 radiographs of adequate quality showing 67 scoliotic curves from children with congenital scoliosis. The end-vertebrae were preselected. Each curve was measured by the Cobb method on two separate occasions by six different observers, using the same goniometer and marker. The intraobserver variability was +/- 9.6 degrees and the interobserver variability +/- 11.8 degrees. If 'significant progression' is to be used as a criterion for surgical fusion in congenital scoliosis, there should be at least a 23 degrees increase, the entire range of the interobserver variability, in the curvature to ensure that the perceived increase is not due to variability in measurement.

Analysis of Variance↗

PubMed1995

The effect of bronchopulmonary dysplasia on growth at school age.

OBJECTIVE: To determine the effect of bronchopulmonary dysplasia (BPD) on growth at school age. DESIGN: A prospective cohort study. METHODS: The sample included 406 children selected from a reconstructed cohort of infants of very low birth weight previously enrolled in a multisite, randomized, controlled clinical trial. The children were contacted at 8 to 10 years of age. Height, weight, and head circumference (HC) were measured. Possible confounders including sociodemographic data, and neonatal factors were also recorded. RESULTS: The children in the BPD group were significantly smaller in weight (z score, -0.50 +/- 1.19 SD vs -0.06 +/- 1.30 SD) and HC (z score, -1.41 +/- 1.32 SD vs -0.63 +/- 1.62 SD) than those without BPD. However, after controlling for cofounders (using analysis of covariance), no significant differences were demonstrated between the two groups. Power analyses showed that a difference of at least 0.43 z score units could have been detected. The previously documented associations between BPD and suspected confounders were reconfirmed. CONCLUSIONS: Significant differences were noted between children with and without BPD for weight and HC but not height. When possible confounders were taken into account, the differences were no longer appreciated. Thus, the previously reported poor growth in children with BPD may have been related to other factors and not necessarily to BPD.

Body Height↗

PubMed1994

Hemostasis and healing of superficial splenic injuries using Nd:YAG laser and nonsuture techniques: preliminary report.

This study was designed to compare Nd:YAG laser to fibrin glue, electrocautery, and avitene in the management of superficial splenic injury. Six dogs were submitted to laparotomy. A #11 blade scalpel was used to sharply excise the splenic capsule inflicting four 1" x 1" superficial injuries on each spleen. The lesions were treated. All animals had a second laparotomy ("first relaparotomy"); 2 dogs each were reexplored on postop days 3, 7, and 14. Morphologic and histologic observations were made. A third and final relaparotomy was performed on all dogs at 21 days with repeated morphologic and histologic assessments. Hemostatic times, grades of adhesions, and microscopic changes were not significantly different among the various treatments (P > 0.25). Capsular plaque formations were significantly different at the first relaparotomy (P < 0.01) and at final relaparotomy (P < 0.05). Both adhesions and capsular plaque formation were least at fibrin glue-treated sites, whereas Nd:YAG (1.06 microns) was most effective for average hemostatic time (mean = 109.67 s). Electrocautery produced the greatest necrosis at treatment sites. We conclude that all modalities are effective in controlling hemorrhage.

Animals↗

PubMed1994

Development of altered taste preferences in tumor-bearing rats.

Experimental tumors induce a decline in food intake that may derive from changes in taste or the development of taste aversions. The preferences of tumor-bearing (TB) and non-tumor-bearing (NTB) rats for five chemicals (three palatable and two aversive taste stimuli) were studied in an animal model of experimental cancer employing the methylcholanthrene (MCA) sarcoma. In protocol 1, five groups of Fischer 344 rats were given 23-h, two-bottle preference tests (taste solution vs. water) daily from day 3 after tumor implantation until spontaneous death occurred. Both NTB and TB rats avoided quinine hydrochloride and hydrochloric acid solutions throughout the experiment indicating that tumor growth produced no disruption in the animals' perception of these normally aversive tastes. In both groups, preference for sucrose (88% to 97%) and saccharin (75% to 93%) remained high until days 22 and 17 respectively, but tended to decline with advanced tumor growth. In both cases, a reduction in total calorie intake preceded the changes in sucrose or saccharin preference by several days. With or without a tumor, rats exhibited approximately 50% preference for NaCl at all times. In protocol 2, a four-bottle preference test (sucrose vs. saccharin vs. NaCl vs. water) was administered before tumor implantation and again 3 weeks later when a decline in food intake was evident. Both TB and NTB rats displayed a dominant preference for sucrose over saccharin, NaCl, and water at the pre- and posttests. However, a comparison of the difference scores (pre- minus postimplantation) of NTB and TB rats showed a small but significant suppression of TB animals' preference for sucrose. The altered preferences for sweet but not salt taste stimuli suggest that food-related taste cues may be more susceptible to the development of taste aversions during cancer. However the contribution of taste changes to the anorexia of cancer remains unclear and it is possible that the changes in taste preference may be secondary to the reduction in food intake.

Animals↗

PubMed1994

Comparison of thallium-201 SPECT redistribution patterns and rubidium-82 PET rest-stress myocardial blood flow imaging.

To compare regional thallium-201 SPECT redistribution patterns with rubidium-82 PET, we studied 81 patients with both imaging modalities. Sixty patients had significant coronary artery disease. All patients underwent PET imaging after dipyridamole infusion, while SPECT imaging was performed after exercise stress (38 patients) and dipyridamole (43 patients). Sixty-eight percent of patients with prior infarct had fixed defects on SPECT, compared to 39% with PET. Sixty-one percent of patients with prior infarct had PET perfusion defects which exhibited 'reflow' or normal rubidium-82 tracer uptake (p < 0.05 vs. SPECT). Similar results were seen in patients without prior infarct (26% fixed defects on SPECT vs. 12% for PET, p < 0.05). Regional analysis showed that 57% of fixed SPECT defects corresponded to PET defects with reflow or normal rubidium-82 uptake, while 78% of 'fixed' PET defects corresponded to fixed SPECT defects. PET reflow and normal rubidium-82 uptake in sites of fixed thallium-201 SPECT perfusion defects suggest that imaging modalities employing separate tracer injections at rest and after stress, such as rubidium-82 PET, may be more specific in the assessment of myocardial viability, especially in patients with prior myocardial infarction.

Aged↗

PubMed1994

Depressed natural killer cell activity in schizophrenic patients.

Factors that suppress natural killer (NK) cell activity were examined in a random sample of 73 schizophrenic patients. NK activity in these patients were compared with 25 healthy age, sex and race matched controls. The mean percent of NK activity was 21% in the schizophrenic group compared with 30% percent in the controls. The difference between these two groups was statistically significant. The mean percent of NK activity in the chronic undifferentiated schizophrenic subgroup and schizoaffective subgroup were 20% and 22% respectively. The degree of suppression of NK activity in the chronic undifferentiated subgroup was higher than in the schizoaffective one, but the difference was not statistically significant. The two subgroups were comparable regarding other immune related variables such as total white cell count, neutrophils, lymphocytes, total protein, albumin, globulin, immunoglobulins and stress. The lower impairment of NK activity in the schizoaffective subgroup may be due to their exposure to lithium which can enhance immune functions. Factors associated with significant suppression of NK activity in schizophrenic patients were physical restraint, number of psychotropic medications, number of chronic non-psychiatric diagnoses and race. Psychosocial stressors were associated with suppression of NK activity but it was not statistically significant. Our results identify factors associated with reduced NK activity observed in certain schizophrenic patients and NK activity in these patients may be the result of interaction between various factors.

Adolescent↗

PubMed1994

Outcome after laminectomy for lumbar spinal stenosis. Part I: Clinical correlations.

All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metropolitan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient questionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore necessary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy.

Adult↗

PubMed1994

Outcome after laminectomy for lumbar spinal stenosis. Part II: Radiographic changes and clinical correlations.

The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels. This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.

Age Factors↗

PubMed1994

The role of the primary care physician in the care of children with serious heart disease.

OBJECTIVE: To determine the roles of primary care physicians and specialists in the medical care of children with serious heart disease. SETTING: Pediatric Cardiology Division; Tertiary Care Children's Hospital. SUBJECTS: Convenience sample of parents, primary care physicians, and pediatric cardiologists of 92 children with serious heart disease. DESIGN: Questionnaire study; questionnaires based on 16 medical care needs, encompassing basic primary care services, care specific to the child's heart disease and general issues related to chronic illness. RESULTS: All children had a primary care physician (PCP), and both they and the parents (P) reported high utilization of PCP for basic primary care services. However, there was little involvement of PCP in providing care for virtually any aspect of the child's heart disease. Parents expressed a low level of confidence in the ability of PCP in general or their child's own PCP to meet many of their child's medical care needs. Both PCP and pediatric cardiologists (PC) were significantly more likely than parents to see a role for PCP in providing for care specific to the heart disease as well as more general issues related to chronic illness. PC and PCP generally agreed about the role PCP should play, although PC saw a bigger role for PCP in providing advice about the child's activity than PCP themselves did. PC were less likely to see the PCP as able to follow the child for long term complications than PCP did. PC were more likely than PCP to believe that PCP were too busy or were inadequately reimbursed to care for children with serious heart disease. Only about one-third of parents reported discussing psychosocial, family, economic, or genetic issues with any provider, and PCP were rarely involved in these aspects of chronic illness. CONCLUSIONS: Primary care physicians do not take an active role in managing either the condition-specific or the more general aspects of this serious chronic childhood illness. With appropriate information and support from their specialist colleagues primary care physicians could provide much of the care for this group of children. Generalists and specialists are both responsible for educating and influencing parents about the role primary care physicians can play in caring for children with serious chronic illness.

Attitude of Health Personnel↗

PubMed1993

Analysis of coronary angioplasty practice in the United States with an insurance-claims data base.

BACKGROUND: Coronary angioplasty is frequently performed in the United States, with more than 300,000 procedures in 1990. Despite the high rate of use of the procedure, there have been few studies addressing practice patterns. METHODS AND RESULTS: From a private insurance claims data base of 5.4 million individuals, a total of 2,101 patients who underwent coronary angioplasty during 1988-1989 were identified. Using their 4,578 hospital admission records and 87,578 outpatient claim records, with an average follow-up of 332 +/- 182 days, we compared patients' outcomes and charges according to whether they had an exercise stress test before the procedure, by sex, by region of the country, and by whether the angioplasty was performed in an institution with a training program. Only 29% of the study cohort had exercise testing before angioplasty; patients in the West (p = 0.001), those undergoing multivessel angioplasty (p = 0.00001), and those whose procedures were performed at sites with training programs (p = 0.04) were more likely to have a screening test, whereas women (p = 0.008) and those with a recent myocardial infarction (p = 0.00001) were less likely to have a screening test. The average length of stay for patients without myocardial infarction as a primary diagnosis was 5.6 days, with a total hospital charge of $15,027. In follow-up, 15.1% had coronary artery bypass surgery and 15% had at least one additional angioplasty procedure; the average follow-up charges were $4,879. Charges varied according to sex, region of the country, and academic status of the angioplasty institution. Certain outcomes showed variation by region of the country and academic status of the angioplasty institution. CONCLUSIONS: The relative lack of an objective definition of myocardial ischemia and the marked variability of use of procedures according to geographic region suggest the need for further implementation of established guidelines.

Age Factors↗

PubMed1993

Type I collagen gene expression in human atherosclerosis. Localization to specific plaque regions.

Because collagen is a major component of the human atherosclerotic plaque, factors controlling collagen synthesis may have a profound influence on the volume growth of these intimal lesions. In human arteries, we compared normal vs atherosclerotic media vs intimas for type I collagen gene expression using immunocytochemistry and in situ messenger RNA hybridization with subsequent correlations with plaque topographical features. We also determined the associations of such collagen gene expression with proximity to monocyte/macrophages and T lymphocytes. Type I collagen synthesis appears to be upregulated in atherosclerotic plaques compared with their underlying medias and normal internal mammary arteries and coronary diffuse intimal thickenings. At least in established and advanced coronary and carotid plaques, type I collagen gene expression is focal and especially prevalent in fibrous cap and vascularized regions. Although macrophages and type I procollagen messenger RNA and protein are both found in atherosclerotic plaques, no apparent spatial correlation between macrophage presence and type I procollagen presence was found within these atherosclerotic intimas. Type I procollagen presence appears to be negatively associated with the spatial presence of T cells. Thus, human atherosclerotic plaques exhibit nonuniform patterns of type I collagen gene expression. Although the biochemical determinants of this focal gene expression have yet to be determined, it is conceivable that stimulatory/inhibitory cytokines and other factors (eg hemodynamics) play important roles in determining the focal nature of collagen synthesis in atherosclerosis.

Arteriosclerosis↗

PubMed1992

Adjuvant treatment using transfer factor for bronchogenic carcinoma: long-term follow-up.

Transfer factor, a dialyzable lymphocyte extract that may act as an immune stimulator by transferring antigen-specific immunity between genetically dissimilar individuals, was administered in a prospective, randomized study to patients with non-small cell bronchogenic carcinoma. Between 1976 and 1982, 63 patients who underwent pulmonary resection, mediastinal lymph node dissection, and, when indicated by the presence of mediastinal lymph node involvement, mediastinal irradiation were randomized into two groups. Group 1 (n = 28) received 1 mL of pooled transfer factor at 3-month intervals after operation; group 2 (n = 35 ) served as controls and received saline solution. There were no statistically significant differences between the two groups with respect to age, sex, tumor histology, stage of disease, or extent of resection. One patient was lost to follow-up at 96 months; follow-up was complete in all others through July 1990. In patients receiving transfer factor, the 2-, 5-, and 10-year survival rates were 82%, 64%, and 43% respectively, whereas in controls they were 63%, 43%, and 23%. Survival in patients receiving transfer factor was consistently better than in those receiving placebo. Furthermore, survival in patients receiving transfer factor was greater at all stages of disease for both adenocarcinoma and squamous cell carcinoma. Although these long-term results were not statistically significant using survival analysis with covariates (p = 0.08), they confirm our previously reported short-term findings suggesting that administration of transfer factor, either through nonspecific immune stimulation, enhancement of cell-mediated immunity, or an as yet undefined mechanism, can improve survival in patients with bronchogenic carcinoma.

Adenocarcinoma↗

PubMed1992

Discordant changes in plasma ACTH and beta-lipotropin/beta-endorphin levels in Cushing's disease patients with depression.

Cushing's Disease is often associated with a depressive syndrome, with mood, vegetative, and cognitive abnormalities of variable severity. In 11 patients with (pituitary ACTH-dependent) Cushing's disease (10 women, 1 man), we studied the relationship between severity of the depressive syndrome and concordance of changes in ACTH and beta-lipotropin/beta-endorphin (beta-LPH/beta-E) levels at baseline and in response to metyrapone and dexamethasone. For each condition, blood samples were drawn at 0800h, 1200h, 1600h, and 2200h. Six patients were categorized as mildly depressed (mean [+/- SD] depressed mood score = 0.17 +/- 0.4; modified Hamilton Depression scale score = 7.6 +/- 4.5) and five as severely depressed (mean depressed mood score = 2.4 +/- 0.5; modified Hamilton Depression scale score = 15 +/- 5.6) (p < 0.05). ACTH and beta-LPH/beta-E were measured by radioimmunoassay. For each experimental condition, changes in levels were scored as concordant if the two peptides moved in parallel between sampling points. There was a relationship between greater severity of depression and more frequent discordant changes in ACTH and beta-LPH/beta-E levels: The six patients with mild depression exhibited 23 concordant and 3 discordant change patterns, while the five patients with severe depression showed 8 concordant and 15 discordant patterns. The mean percentage of concordant patterns per patient differed significantly between the two groups (mildly depressed = 90.0 +/- 16.7; severely depressed = 34.6 +/- 8.7 (p < 0.001). When each study condition was examined separately, differences in the frequency of concordance between the groups reached significance during the post-metyrapone phase and with 8.0 mg dexamethasone administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗

PubMed1992

Impact of self-management education on the functional health status of older adults with heart disease.

This paper presents findings from the evaluation of a self-management education program based on self-regulation principles. Older men and women (N = 324) were randomly assigned to program and control groups. Outcomes were measured using the Sickness Impact Profile. Twelve months following baseline data collection, psychosocial functioning of program participants was significantly better than that of controls. Different program effects were noted when results were analyzed by participant gender.

Activities of Daily Living↗