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Biomedical subjects

J Zimmerman

Publications and source records attributed to J Zimmerman.

At least 37 records · Page 2Linked to original sources
PubMed1998

The Apache III prognostic system: customized mortality predictions for Spanish ICU patients.

OBJECTIVE: To customize the Acute Physiology and Chronic Health Evaluation (APACHE) III mortality equation for Spanish admissions to the intensive care unit (ICU) and evaluate its discrimination and calibration. DESIGN: Prospective multicenter inception cohort study. SETTING: 86 ICUs located in all regions of Spain. PATIENTS: 10,929 adult patients selected by a systematic sampling method. All types of critical care patients were included, including coronary bypass patients, but excluding those with burn injury, those admitted for pacemaker implants, patients under 16 years of age, and patients with length of ICU stay < 6 h. MEASUREMENTS AND RESULTS: Data collection in the first 24 h after patient admission included: APACHE III score, treatment location prior to ICU admission, and main ICU admission diagnosis. Using these variables, a model for predicting hospital mortality was constructed, adapted to Spain, and its discriminating ability was assessed by the area below the ROC curve, which was 0.83. The model was validated using the jacknife method and the area below the receiver operating characteristic (ROC) curve for the cross-validated predictions was 0.82. The percentage of patients correctly classified at 0.50 risk of death was 82.3%. Model calibration was evaluated by analysis of the agreement between the observed and cross-validated predicted mortality using the Hosmer-Lemeshow test, which gave a value of (H) 12.27, with no statistical significance, i.e., good calibration. CONCLUSIONS: We have customized the APACHE III mortality prediction system for the Spanish population. This adapted model has demonstrated the requisite validation, calibration, and discrimination for its use among Spanish critical care patients.

APACHE↗
PubMed1998

Hypnotic technique for sedation of patients during upper gastrointestinal endoscopy.

A method of sedation of patients undergoing upper gastrointestinal endoscopy is described. This technique employs a variety of elements, including "pacing and leading," metaphors, use of physiological reactions to deepen the relaxation, imagery, and post hypnotic suggestions. It is a simple and effective method which does not require any preparation. It spares the need for a pharmacological sedation and obviates the possible hazards of such a sedation. The author has successfully used this technique to sedate more than 200 patients undergoing upper gastrointestinal endoscopy. The duration of examinations performed this way compares with that using conventional pharmacological sedation. However, unlike the case of pharmacological sedation, no further monitoring is needed after the completion of the examination and the patients can leave the clinic immediately to resume their activities.

Endoscopy, Gastrointestinal↗
PubMed1998

Helium-oxygen improves Clinical Asthma Scores in children with acute bronchiolitis.

OBJECTIVE: To determine the efficacy of a helium-oxygen mixture in children admitted to the pediatric intensive care unit with acute respiratory syncytial virus (RSV) bronchiolitis. DESIGN: Randomized, double-blind, controlled, crossover study and nonrandomized, prospective study. SETTING: A pediatric intensive care unit in a university hospital. PATIENTS: Nonintubated children with signs of acute lower respiratory tract infection and a positive rapid immunoassay for RSV admitted to the pediatric intensive care unit. INTERVENTIONS: Treatment with either helium-oxygen or air-oxygen was administered in random order for 20 mins. Nonrandomized patients received helium-oxygen as initial therapy. MEASUREMENTS AND MAIN RESULTS: Clinical Asthma Score, respiratory rate, heart rate, and pulse oximetry oxygen saturation values were recorded at baseline (before randomization) and at the end of each 20-min treatment period (helium-oxygen or air-oxygen). Nonrandomized patients were studied 20 mins into helium-oxygen delivery. Eighteen patients were studied, 13 of whom were randomized. Five children with severe bronchiolitis (Clinical Asthma Score of > or =6) were initially given helium-oxygen and scored at 20 mins. Mean Clinical Asthma Score was 3.04 (range 1 to 7.5) in the 13 randomized patients and 4.25 (range 1 to 9) in the 18 patients overall. Clinical Asthma Score decreased in the 13 randomized patients (mean 0.46, p < .05) and in the 18 patients overall (mean 1.23, p < .01) during helium-oxygen delivery. In randomized patients with Clinical Asthma Scores of <6 (n = 12), a positive correlation (rs = .72) was observed between the Clinical Asthma Score at baseline and the change in Clinical Asthma Score during helium-oxygen administration (p = .009). Respiratory rate and heart rate decreased during helium-oxygen treatment but were not statistically significant. No complications occurred during helium-oxygen delivery. CONCLUSIONS: Inhaled helium-oxygen improves the overall respiratory status of children with acute RSV lower respiratory tract infection. In patients with mild-to-moderate bronchiolitis (Clinical Asthma Scores of <6), the beneficial effects of helium-oxygen were most pronounced in children with the greatest degree of respiratory compromise.

Acute Disease↗
PubMed1998

Electromagnetic interference from a muscle stimulation device causing discharge of an implantable cardioverter defibrillator: epicardial bipolar and endocardial bipolar sensing circuits are compared.

This case report is about two patients with two different types of ICDs who underwent electrical muscle stimulation (EMS) therapy. In one patient with an ICD that has epicardial screw-in bipolar sensing leads, electromagnetic interference (EMI) from the EMS device caused the delivery of an inappropriate ICD discharge. In a second patient with an ICD with endocardial true bipolar sensing, there was no evidence of EMI during the EMS therapy despite all of our attempts to reproduce it. The sensing circuits in the two different ICDs are compared.

Aged↗
PubMed1997

Kinetics and dynamics of single oral doses of sirolimus in sixteen renal transplant recipients.

Sirolimus is a new immunosuppressive drug that has been evaluated in animal experiments. The current study was conducted on humans with reformulated sirolimus in doses from 3 mg/m2 to 15 mg/m2. Sixteen renal transplant recipients were included in this phase I study to determine the safety, tolerance, and preliminary pharmacokinetics of increasing single doses of orally administered sirolimus. All 16 patients had stable renal graft function after a renal transplant at least 6 months before the study. Basal immunosuppression consisted of cyclosporine and prednisolone (n = 10) or cyclosporine, azathioprine, and prednisolone (n = 6). Four groups (I, 3 mg/m2; II, 5 mg/m2; III, 10 mg/m2; IV, 15 mg/m2) of four patients were assigned randomly to receive sirolimus (n = 3) or placebo (n = 1). Among the 12 patients who received sirolimus, five had mild transient study events such as headache, nausea, mild dizziness, hypoglycemia, epistaxis, and decrease in platelets. No serious adverse events occurred and no nephrotoxic effects could be related to the single dose administration of sirolimus. The only study event that was judged as probably related to sirolimus was the single case of thrombocytopenia. The other events were evaluated as possibly related. Thrombocytopenia occurred at the highest dose level (15 mg/m2 sirolimus). In two of the patients in the placebo group, slight elevations of liver enzymes and serum amylase were seen. Blood and plasma sirolimus concentrations were analyzed by an electrospray-high performance liquid/mass spectrophotometric (ESP-HPLC/MS) method Sirolimus showed an extensive red blood cell distribution with a mean blood/ plasma ratio of 49.1. The elimination half-life ranged from 43.8 to 86.5 hours (mean 56.9 hours). The Cmax and the area under the concentration versus time curves (AUC) correlated reasonably with doses from 3 to 15 mg/m2. The oral dose clearance ranged from 42 to 339 ml/h.kg. No clinically significant differences were seen in the trough concentrations of cyclosporine or the AUCs before and after the administration of sirolimus. Administration of single oral doses of sirolimus from 3 to 15 mg/m2 was safe and well tolerated in stable renal transplant recipients. Thrombocytopenia may be the dose-limiting toxicity. Additional phase II and phase III clinical trials will define the immunosuppressive efficacy of sirolimus.

Administration, Oral↗
PubMed1997

Successful surgical removal of an asymptomatic optic nerve hemangioblastoma in von Hippel-Lindau disease.

An asymptomatic patient with a family history of von Hippel-Lindau disease carried the abnormal gene for this disease. An imaging survey that consisted of computed tomography, magnetic resonance imaging, and cerebral angiography revealed an optic nerve hemangioblastoma. The potential for visual loss in the future was the indication for microsurgical intervention. This was the first asymptomatic optic nerve hemangioblastoma to be imaged and the first to be successfully removed without any permanent neurological deficits or vision loss.

Adult↗
PubMed1997

Esophagitis is a major cause of upper gastrointestinal hemorrhage in the elderly.

BACKGROUND: The risk of death in patients presenting with upper gastrointestinal (UGI) hemorrhage increases with age. Our aims were to define the background characteristics, causes, course, and outcome in patients aged > or = 80 years admitted to hospital because of acute UGI bleeding (n = 115) in relation to patients aged 60-69 years admitted for the same reason (n = 133). METHODS: A prospective, longitudinal study with a nested case-control analysis was carried out. RESULTS: In the elderly patients there was a female preponderance and a significantly higher prevalence of atherosclerotic cardiovascular disease. By contrast, use of tobacco and alcohol, diabetes mellitus, and chronic liver disease were significantly commoner in the controls. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, anticoagulants, and corticosteroids was similar in the two groups. Esophagitis was the cause of bleeding in 21.1% of the elderly, as compared with 3.3% in the controls. The relative risk of developing esophagitis in the elderly was increased and was independent of gender, smoking, alcohol consumption, use of NSAIDs, aspirin, or corticosteroids, diabetes mellitus, atherosclerotic cardiovascular disease and liver disease. (Adjusted odds ratio, 18.1; P = 0.0002). The rates of persistent or recurrent bleeding and emergency surgery to control bleeding were similar. However, the mortality in the elderly was higher (13 versus 6.1%; P = 0.09). CONCLUSIONS: Age > or = 80 years is an independent determinant of esophagitis, a major cause of UGI bleeding in the elderly.

Age Factors↗
PubMed1997

Mastectomy without malignancy after carcinoma diagnosed by large-core stereotactic breast biopsy.

Mammary carcinoma diagnosed by large-core stereotactic biopsy (LCSBB) is often followed by definitive surgery. We report on positive (malignant) LCSBB followed by definitive surgery that failed to demonstrate malignancy. Between January 1993 and August 1996, 206 women in our institution underwent LCSBB. Carcinoma was diagnosed in 45 patients (22%) of the 206 (ductal carcinoma in situ (DCIS), n = 12; invasive carcinoma, n = 33). Twenty-nine of the 45 patients subsequently underwent mastectomy, and 8 of 45 underwent lumpectomy. In 34 (92%) of these 37 patients, carcinoma was demonstrated at follow-up surgery, but in 3 patients (8%), mastectomy failed to reveal carcinoma. The characteristics of these three patients are as follows: Patient 1 was a 58-year-old woman with a nonpalpable 6- to 8-mm nodule revealed by a screening mammogram. Three of 8 LCSBBs showed colloid carcinoma, but histologic examination of 50 paraffin blocks and radiographic examination of the mastectomy sample failed to reveal carcinoma. Patient 2 was a 64-year-old woman with a nonpalpable 6- to 9-mm nodule revealed by mammogram. Six of 12 LCSBBs showed tubular carcinoma, but histologic examination of 30 paraffin blocks from her mastectomy sample failed to reveal carcinoma. Patient 3 was a 72-year-old woman with a history of DCIS. She had undergone a lumpectomy and radiotherapy, and she had suspicious ipsilateral microcalcifications. Two of 8 LCSBBs showed comedo DCIS, but histologic examination of 26 paraffin blocks and radiographic examination of the mastectomy sample failed to reveal carcinoma. Possible explanations for a mastectomy without malignancy after carcinoma was diagnosed by LCSBB include removal of the entire lesion by LCSBB, inflammatory response obliterating remaining tumor, false-positive core biopsy result, patient misidentification, inadequate sampling of the surgical specimen, and failure to remove the tumor. We outline a series of steps for the pathologists to follow when confronted with such a case.

Adenocarcinoma↗
PubMed1996

Analysis of the oxidative catabolism of retinoic acid in rat Dunning R3327G prostate tumors.

We studied the enzymatic characteristics of the oxidative catabolism of retinoic acid (RA) and its inhibition by liarozole-fumarate in homogenates of rat Dunning R3327G prostate tumors. Homogenates of rat liver were used as reference material. Both tumor and liver homogenates were able to catabolize retinoic acid. HPLC analysis revealed only very polar metabolites in tumors, while in the liver both metabolites with intermediate polarity and more polar metabolites were found. Kinetic analysis of retinoic acid catabolism showed a K(m) of 1.7 +/- 0.7 microM and a Vmax of 4.2 +/- 4.4 pmol polar RA metabolites/mg protein/hr for Dunning G tumor homogenates. In liver homogenates a K(m) value of 4.3 +/- 0.5 microM and a Vmax value of 290 +/- 120 pmol polar RA metabolites/mg protein/hr were obtained. Liarozole-fumarate inhibited retinoic acid catabolism in Dunning tumors and liver with IC50 values of 0.26 +/- 0.16 microM and 0.14 +/- 0.05, respectively. The results suggest that rat Dunning R3327G tumors are able to metabolize retinoic acid in a manner similar to that found in rat liver but with a lower metabolizing capacity.

Animals↗
PubMed1996

CSF inositol does not predict antidepressant response to inositol. Short communication.

CSF inositol was reported to be reduced in depression and inositol has been reported to be effective in treatment of depression. We studied CSF inositol in 18 drug-free depressed patients and 36 normal controls; the depressed patients then participated in an open trial of 18 gm daily inositol treatment for 4 weeks. There was no difference in pre-treatment CSF inositol between depressed patients and controls. CSF inositol levels did not predict response on the Hamilton Depression Scale to 4 weeks of inositol treatment.

Adult↗
PubMed1996

Vitamin C status and colonic neoplasia.

PURPOSE: A subnormal status of vitamin C has been associated with an increased risk for several malignant diseases and may play a causative role in their development. The aim of the present study was to investigate whether this occurs also in neoplasms of the colon. METHODS: We have studied dietary intake and status of vitamin C in a consecutive group of patients with adenomatous colonic polyps (n = 31) and compared it with that of patients with no such history and a normal colonic mucosa, as confirmed by colonoscopy (n = 54). RESULTS: Dietary intake of this vitamin, as assessed by the dietary recall method, was similar in the two groups, as were the levels of vitamin C in plasma and leukocytes. There were no significant differences in intake of dietary fiber, fat, vitamin A, or calcium between the two groups. Lack of association between vitamin C intake or status and colonic polyps persisted after adjustment for potential confounders. CONCLUSION: We conclude that in this population, a deficient status of vitamin C is not an important factor in colonic neoplasia.

Adenomatous Polyps↗
PubMed1996

Folate synthesized by bacteria in the human upper small intestine is assimilated by the host.

BACKGROUND & AIMS: Some intestinal flora are known to synthesize folate. The aim of this study was to determine whether folate synthesized by small intestinal flora is assimilated by the human host. METHODS: Subjects with atrophic gastritis and healthy volunteers were studied before and after omeprazole administration. A double-lumen perfusion tube was placed in the duodenum. 3H-labeled P-aminobenzoic acid, a precursor substrate for bacterial folate synthesis, was perfused. Downstream intestinal aspirates and a 48-hour urine collection were obtained. RESULTS: Atrophic gastritis and omeprazole administration were associated with increases in duodenal pH and in small intestinal flora. Bacterially synthesized folates were isolated from the intestinal aspirates. Tritiated 5-methyltetrahydrofolate, a major metabolite of folate, was isolated from the urine of omeprazole-treated subjects in greater quantities than from drug-free subjects (P<0.01); the quantity of tritiated 5-methyltetrahydrofolate in the urine of the subjects with atrophic gastritis was similarly elevated. CONCLUSIONS: (1) Mild bacterial overgrowth caused by atrophic gastritis and administration of omeprazole are associated with de novo folate synthesis in the lumen of the small intestine; (2) the human host absorbs and uses some of these folates; and (3) the contribution to folate nutriture from this source remains unclear.

4-Aminobenzoic Acid↗
PubMed1996

Isolation of the ALG6 locus of Saccharomyces cerevisiae required for glucosylation in the N-linked glycosylation pathway.

N-Linked protein glycosylation in most eukaryotic cells initiates with the transfer of the oligosaccharide Glc3Man9GlcNAc2 from the lipid carrier dolichyl pyrophosphate to selected asparagine residues. In the yeast Saccharomyces cerevisiae, alg mutations which affect the assembly of the lipid-linked oligosaccharide at the membrane of the endoplasmic reticulum result in the accumulation of lipid-linked oligosaccharide intermediates and a hypoglycosylation of proteins. Exploiting the synthetic growth defect of alg mutations in combination with mutations affecting oligosaccharyl transferase activity (Stagljar et al., 1994), we have isolated the ALG6 locus. alg6 mutants accumulate lipid-linked Man9GlcNAc2, suggesting that this locus encodes an endoplasmic glucosyltransferase. Alg6p has sequence similarity to Alg8p, a protein required for glucosylation of Glc1Man9GlcNAc2.

Amino Acid Sequence↗
PubMed1996

Adolescents' views of sexual decision-making.

The purpose of this study was to ascertain the reasons adolescents give for abstinence, safer sex, and unprotected sexual intercourse. Participants were 115 high school students living in a midwestern state; average age was 17.5 years. Students completed a two-part questionnaire about (a) their expectations for the outcome of a vignette in which two teenagers had the opportunity for intercourse and (b) their ideas about the reasons, thoughts, and feelings associated with three possible endings to the vignette-abstinence, intercourse with a condom, unprotected intercourse. Content analysis of responses indicated that four interconnected factors are significant contributors to sexual behavior: social norms, fear, gratification or pleasure, and availability of condoms.

Adolescent↗
PubMed1996

Reduced glutamine content in colonic polyps.

BACKGROUND: Glutamine is the most abundant amino acid in the body. It has a key role in nitrogen metabolism and is a major source of energy for the enterocyte and many other cells. Glutamine is also essential for tumor growth, and marked changes in organ glutamine metabolism are characteristic in cancer patients. METHODS: We have investigated the catabolism of glutamine in a classic premalignant condition: the colonic adenomatous polyp. The content of glutamine and activity of two catabolic enzymes, glutamine transferase and phosphate-dependent glutaminase, were studied in normal colon and in polyp mucosa. RESULTS: Free glutamine content and activity of glutaminase were significantly lower in polyps than in their adjacent mucosa. Glutamine transferase activity was significantly lower in polyp mucosa than in normal colon controls. CONCLUSIONS: Adenomatous polyps might behave as a glutamine trap, channeling glutamine to protein and nucleic acid synthesis. These changes in glutamine catabolism could play a role in colonic neoplasia pathogenesis.

Acyltransferases↗