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Biomedical subjects

J Stern

Publications and source records attributed to J Stern.

At least 73 records · Page 4Linked to original sources
PubMed1997

Contraceptives for lactating women: a comparative trial of a progesterone-releasing vaginal ring and the copper T 380A IUD.

From approximately one week before normal ovulation resumes, lactating women require protection against pregnancy by a contraceptive that is safe for both infant and mother in a multicenter one-year study, the natural hormone, progesterone, delivered vaginally by a sequence of four contraceptive rings designed for continuous use, was evaluated as a contraceptive for nursing mothers in comparison with the Copper T 380A IUD. Individual rings release in effective average dose of 10 mg day for a 3 month period. Evaluation included measures of lactational performance as well as of contraceptive efficacy and safety to mother and child. Nine participating clinics enrolled 802 ring users and 734 IUD acceptors between postpartum days 29 and 63. Life table analyses were performed with parallel decrements for ring and IUD subjects. Continuation in the study and analysis required that subjects not stop breastfeeding. The ring, with a one-year pregnancy rate of 1.5 per 100, did not differ significantly from the IUD with respect to contraceptive effectiveness (p > 0.05). More than half of the ring subjects were continuing at 6 months post admission and a quarter (23.5 per hundred) were still using the ring and breastfeeding one year after admission. Women with the IUD, however, had higher continuation rates (p < 0.001) at both time points. The largest single decrement for each method was that for weaning. Ring users had more complaints of vaginal problems but had fewer vaginal disorders on examination. At 12 months postpartum, 46 per 100 continuing ring users remained in amenorrhea. Lactation performance and the health and weight gain of the infants were similar among users of either regimen.

Administration, Intravaginal↗
PubMed1997

First week drug concentrations in women with levonorgestrel rod or Norplant capsule implants.

Forty-two healthy women volunteered to have blood samples drawn at 2, 4, 8, 24, 48, and 168 h (7 days) following placement of levonorgestrel-releasing rod (LNG rod) or of Norplant capsule implants to permit measurement of drug concentrations. Three clinics recruited 10 women each, half of whom used each type of implant. Twelve additional subjects were later enrolled at one site to provide greater detail for the capsule implants. Throughout the week, women with Norplant implants had apparently higher mean drug concentrations than did women with LNG rod implants, but the differences were significant only in the first 48 h after placement (p < 0.05). Maximum levels for capsule implants were found at the 24-h sample (mean, 1358 to 1474 pg/mL) and for the LNG rod implants at 48 h (772 pg/mL). Body weight was negatively correlated with levonorgestrel concentrations at all times (p < 0.05). For several sampling times, differences between clinics in mean concentrations were statistically significant after weight adjustment. Despite differences by implant type, weight, or clinic location, drug concentrations compatible with contraceptive effect were attained within 24 h in users of LNG rod or of Norplant implants, insofar as all women had levonorgestrel concentrations above 250 pg/mL at the 24-h sample.

Adolescent↗
PubMed1997

Validation of the Charlson comorbidity index in patients with head and neck cancer: a multi-institutional study.

Comorbid conditions are medical illnesses that accompany cancer. The impact of these conditions on the outcome of patients with head and neck cancer is well established. However, all of the comorbidity studies in patients with head and neck cancer reported in the literature have been performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce and validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use. Study design was a retrospective cohort study. The study population was drawn for three academic tertiary care centers and included 88 patients 45 years of age and under who underwent curative treatment for head and neck cancer. All patients were staged by the KFI and the CI for comorbidity and divided into two groups based on the comorbidity severity staging. Group 1 included patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully applied to 80% of this study population, and the CI was successfully applied in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices independently predicted the tumor-specific survival (P = 0.007), even after adjusting for the confounding effects of TNM stage by multivariate analysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidity staging by the CI independently predicted survival, was easier to use, and more readily applied, it may be better suited for use for retrospective comorbidity studies.

Adult↗
PubMed1997

HM-PAO (CERETEC) SPECT brain scanning in the diagnosis of Alzheimer's disease.

OBJECTIVE: To evaluate the accuracy of Single Photon Emission Computed Tomography (SPECT) scanning in the diagnosis of Alzheimer's Disease (AD) and its capacity to improve the diagnostic accuracy of conventional clinical evaluation. DESIGN: Comparison of SPECT scanning of AD and normal subjects with the criterion standard of clinical diagnosis confirmed by 1-year repeated evaluation. SETTING: A memory clinic in a tertiary care university hospital. PATIENTS: One hundred twenty patients were evaluated upon entering the Jewish General Hospital (McGill University) Memory Clinic. Fifty-eight patients were diagnosed as having AD and 17 as having vascular dementia. Twenty unmatched controls (recruited mainly through newspaper advertisements) were normal, and 25 had cognitive impairment without dementia (not included in the statistical analysis). MAIN OUTCOME MEASURES: Comparison of visual inspection of SPECT, based on the system of classification developed by Holman et al., using B pattern alone as positive or B (bilateral posterior temporal and/or parietal cortex deficits) or C (bilateral posterior temporal and/or parietal deficits with additional defects) pattern and B or C or D (unilateral posterior temporal and/or parietal defects with or without additional defects) as positive compared with clinical diagnosis after repeated evaluations. Sensitivity and specificity, as well as positive predictive value (PPV) and negative predictive value (NPV) based on the prevalence of AD in a memory clinic setting of 30% or 50%, were calculated. RESULTS: With B pattern as positive, the sensitivity of SPECT was 21% whereas the specificity was 80%. With B or C as positive, the sensitivity was 29% and the specificity was 75%. With B or C or D as positive, the sensitivity was 55% and the specificity was 65%. With a 30% prevalence, the PPV with B pattern as positive was 31% whereas the NPV was 30%. The PPV with B or C as positive was 33% while the NPV was 29%, and the PPV with B or C or D as positive was 40% whereas the NPV was 23%. With a 50% prevalence, the PPV with B pattern as positive was 51% and the NPV 49.6%; the PPV with B or C as positive was 54% and the NPV 48.6%; the PPV with B or C or D as positive was 61% while NPV was 41%. CONCLUSION: The sensitivity and specificity were too low for SPECT to be useful as a diagnostic test for AD. The poor positive and negative predictive values in our tertiary care clinic mean that SPECT is not useful in "ruling-in" or "ruling-out" AD in that setting. In fact, clinical evaluation is more accurate.

Aged↗
PubMed1996

[Decompensated acute gastric dilatation caused by a bulimic attack in anorexia nervosa].

HISTORY AND CLINICAL FINDINGS: Abdominal pain developed after a bulimic binge in a 19-year-old girl with anorexia nervosa. She had unsuccessfully tried to induce vomiting. Physical examination showed no clinical sign of peritonitis, although there was diffuse abdominal tenderness on pressure. INVESTIGATIONS: There was leukopenia (2200 G/l) and a raised serum lactate level (58 mg/dl). No free air was seen on a plain film of the abdomen. Abdominal sonography revealed little free fluid subhepatically. TREATMENT AND COURSE: Acute respiratory impairment during investigations required emergency intubation. As bronchoscopy revealed aspiration a bronchial lavage was performed. Under gastroscopic control gastric emptying was achieved through a large gastric tube. After early improvement the patient developed the full picture of sepsis. Ultrasonography and needle puncture having revealed purulent intraabdominal fluid, a laparotomy was performed, which showed necrosis of the anterior and posterior walls of the stomach with free perforation. The greater curvature was resected. The patient slowly recovered but a relaparotomy for a subphrenic abscess became necessary on the 10th postoperative day. A year later there was free food passage, but the anorexia nervosa was unchanged. CONCLUSION: A bulimic binge can become life-threatening if the stomach does not empty spontaneously. Surgical intervention is required, if the patient's condition does not improve despite gastric emptying.

Adult↗
PubMed1996

Contribution of cardiopulmonary indices in the assessment of patients with silent and symptomatic ischemia during exercise testing.

Cardiopulmonary and radionuclear indices were used to evaluate and compare cardiac function during exercise testing in patients with symptomatic and silent ischemia. The study comprised 58 patients aged 35-74 years, divided into three groups: Group I-20 patients (controls) with neither ST depression nor chest pain; Group II-22 patients with ST depression > 1 mm and no chest pain; Group III-16 patients with both ST depression and chest pain. All patients in Groups II and III demonstrated significant coronary artery disease. No antianginal medication was taken at least 24 h before testing. All patients underwent a cardiopulmonary exercise test and a multigated acquisition radionuclear study. The following variables were measured: oxygen consumption (VO2), CO2 output (VCO2), minute ventilation (VE), O2-pulse, ventilatory anaerobic threshold (VAT), left ventricular ejection fraction (LVEF) at rest (r) and at maximal effort (ex). Probability values were significant for all variables (P < 0.01-0.0001) except left ventricular ejection fraction-rest (P not significant between the three groups). No significant differences in extent of coronary artery disease were noted between Groups II and III. These findings suggest that during exercise testing patients with silent ischemia have better overall cardiac function than patients with symptomatic ischemia. Their value for both cardiopulmonary and radionuclear indices are closer to those of the control group than to the symptomatic group, regardless of the severity of the coronary artery disease Summary of results: (mean +/- 1 S.D.) Group VO2-max O2-Pulse max VAT (%) VAT (ml/min) LVEF-rest delta LVEF (ex-r) I 25.2 +/- 6.3 15.7 +/- 3.4 51.2 +/- 6.6 1075 +/- 289 54.7 +/- 7 5.4 +/- 4.85 II 22.4 +/- 2.8 14.5 +/- 2 47.0 +/- 5.3 854 +/- 136 52 +/- 10 1.2 +/- 6.7 III 16.0 +/- 2.5 11.4 +/- 2 41.6 +/- 7.7 683 +/- 105 51 +/- 8.5 -5.87 +/- 6.3

Adult↗
PubMed1996

Astrocyte leucine metabolism: significance of branched-chain amino acid transamination.

We studied astrocytic metabolism of leucine, which in brain is a major donor of nitrogen for the synthesis of glutamate and glutamine. The uptake of leucine into glia was rapid, with a Vmax of 53.6 +/- 3.2 nmol/mg of protein/min and a Km of 449.2 +/- 94.9 microM. Virtually all leucine transport was found to be Na+ independent. Astrocytic accumulation of leucine was much greater (3x) in the presence of alpha-aminooxyacetic acid (5 mM), an inhibitor of transamination reactions, suggesting that the glia rapidly transaminate leucine to alpha-ketoisocaproic acid (KIC), which they then release into the extracellular fluid. This inference was confirmed by the direct measurement of KIC release to the medium when astrocytes were incubated with leucine. Approximately 70% of the leucine that the glia cleared from the medium was released as the keto acid. The apparent Km for leucine conversion to extracellular KIC was a medium [leucine] of 58 microM with a Vmax of approximately 2.0 nmol/mg of protein/min. The transamination of leucine is bidirectional (leucine+alpha-ketoglutarate<==>KIC+glutamate) in astrocytes, but flux from leucine-->glutamate is more active than that from glutamate-->leucine. These data underscore the significance of leucine handling to overall brain nitrogen metabolism. The release of KIC from glia to the extracellular fluid may afford a mechanism for the "buffering" of glutamate in neurons, which would consume this neurotransmitter in the course of reaminating KIC to leucine.

Amination↗
PubMed1996

Relationship between p53 mutation incidence in oral cavity squamous cell carcinomas and patient tobacco use.

It is well-established that a high incidence of p53 mutations exist in oral cavity squamous cell carcinomas (OCSCCs). To determine whether p53 mutations are etiologically associated with OCSCC development or are associated with exposure to specific carcinogens, we have analyzed the conserved regions of the p53 gene (exons 5-9) in 48 OCSCCs obtained from patients with varied tobacco and alcohol use histories by polymerase chain reaction/single strand conformational polymorphism (PCR/SSCP) and DNA sequencing analysis. Thirty-eight percent (18/48) of the OCSCCs exhibited a mutation in exons 5-9 of the p53 gene. There was a significantly higher incidence of p53 mutations in OCSCCs from tobacco users (predominantly cigarette smokers) compared to those who had never used tobacco. No increase in the incidence of p53 mutation was observed in tobacco users who drank alcohol. G to A transitions and deletions were the predominant mutations observed in OCSCCs from tobacco users. No specific pattern of mutation was observed in OCSCCs from those subjects who had never used tobacco. These data suggest that a history of tobacco use was associated with a high incidence of p53 mutations in patients with OCSCC and that tobacco carcinogens include a specific pattern of mutations in oral cavity tissue in vivo.

Adult↗
PubMed1996

Pouch-anal cancer after restorative proctocolectomy for familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) and idiopathic ulcerative colitis are both mucosal diseases that bear a significant risk of developing colorectal cancer. As a consequence, their surgical treatment is currently widely performed by restorative proctocolectomy with pelvic ileal pouch-anal anastomosis (IPAA). Herein we report a new case of cancer after IPAA that developed in a 33-year-old woman with FAP. Pouch-anal cancer was diagnosed 8 years after restorative proctocolectomy, including anorectal mucosectomy, for FAP with manifest cancer in the sigmoid colon. This case observation reemphasizes that the risk of cancer for FAP patients persists as long as any rectal mucosa remains after IPAA surgery.

Adenocarcinoma↗
PubMed1996

Albert F. Ax (1913-1994).

Al Ax's contributions to psychology and psychophysiology span almost 40 years. He had many colleagues with whom he communicated openly and generously about his early psychophysiological research. One of these, John Stern, comments below. Joanne Fetzner, a close associate of Al's during his years as director of the Psychophysiology Laboratory of the Lafayette Clinic in Detroit, Michigan, and as founder of the Society for Psychophysiological Research and founding editor of Psychophysiology, provides a more detailed account of Al's life and his contributions to psychophysiological research as well as his untiring efforts to gather together this research into a scientific journal and its scientists into a formal society, both dedicated to the furtherance and scientific recognition of psychophysiological research.

History, 20th Century↗
PubMed1996

[Changes in fecal bile acid excretion after proctocolectomy].

To study the effect of total colectomy for fecal bile acid excretion we examined groups of patients with ulcerative colitis and familial adenomatous polyposis coli 4,8 +/- 2.9 years after surgery. Patients after total colectomy showed a significant higher fecal bile acid excretion compared to healthy persons (mean +/- SD: 190.8 +/- 195.2 mumol/d). The highest fecal output occurred in patients with permanent ileostomies (mean +/- SD: 7595.0 +/- 5651.4 mumol/d), it was significantly higher compared to patients with ileoanal pouch anastomosis (mean +/- SD: 2212.8 +/- 2132.8 mumol/d). The daily fecal output of patients with ileorectal anastomosis (mean +/- SD: 4331.8 +/- 6314.7 mumol/d) is between the results of both other groups without any significance. After total colectomy only primary bile acids were found in each group whereas healthy people had almost identically rates of primary and secondary bile acids in their stools.

Adenomatous Polyposis Coli↗
PubMed1996

[Vital preoperative function diagnosis in deep anterior rectum resection].

Restoration of continuity after deep anterior resection may lead to major functional problems. Preoperative functional evaluation of the anal sphincter should help to select patients unsuitable for reconstruction and produce more objective data for evaluation of new technical procedures. In addition to a standardized history of continence and the clinical examination, anorectal manometry and endosonography of the sphincter are adequate methods.

Anal Canal↗
PubMed1996

[Restorative proctectomy, reconstruction of continuity with or without colon J pouch].

Of 63 patients undergoing deep anterior resection of the rectum, 39 patients received a straight colo-anal anastomosis (CAA), 24 additionally had a colon-j-pouch (CPA) constructed. Local septic complications occurred in 12.5% of patients after pouch-anal anastomosis compared to 20.5% after colo-anal anastomosis: stool frequency, after pouch-anal anastomosis was 3.3 per 24 h compared to 5.2 per 24 h after straight anastomosis within the first year after ileostomy closure (p = 0.053); continence was slightly better in the pouch group (n.s.); and anal manometry showed a significant postoperative decrease only in resting pressure after straight colo-anal anastomosis (p < 0.001). Pouch construction should be considered after deep rectal resection, as it seems to improve functional outcome and has fewer local septic complications than straight anastomosis.

Fecal Incontinence↗
PubMed1995

Apoptosis occurs in the oligodendroglial lineage, and is prevented by basic fibroblast growth factor.

During the perinatal period, oligodendroglial precursor cells proliferate rapidly, then cease dividing and differentiate into oligodendroglia. Many of these newly formed oligodendroglia are destined to die. We now demonstrate that oligodendroglia generated in passaged cultures of rat forebrain oligodendroglial precursor cells after removal of basic fibroblast growth factor (basic FGF) from the medium often undergo internucleosomal DNA nicking and nuclear fragmentation, features characteristic of apoptosis. These alterations are rare in cultures maintained continuously in basic FGF. As in many other cellular lineages susceptible to apoptosis, these degenerative changes can be prevented by treatment with the endonuclease antagonist, aurintricarboxylic acid, or by inhibiting de novo RNA or protein synthesis. Supplementation of the basic FGF-free medium with insulin, insulin-like growth factor-1, platelet-derived growth factor, or ciliary neuronotrophic growth factor also diminishes DNA nicking. Both oligodendroglial differentiation and DNA nicking are induced in basic FGF-treated cultures by inhibiting DNA synthesis with aphidicholin or excess thymidine, thus suggesting a close linkage between the anti-apoptotic, anti-differentiation, and mitogenic effects of basic FGF on the oligodendroglial lineage.

Animals↗
PubMed1995

Partial purification of a novel mitogen for oligodendroglia.

A protein with a MWapp of 50-70 kDa isolated from the salt extract of crude membranes from neonatal rat brain increases the numbers of oligodendroglia in mixed glial cultures prepared from neonatal rat cerebral white matter. After partial purification by ion exchange and gel exclusion chromatography, and elution from an SDS-polyacrylamide gel, this protein ("oligodendroglial trophic factor," OTF) elicited half-maximal oligodendroglial recruitment at a concentration of 5 ng/mL. OTF is a mitogen for oligodendroglia, and to a lesser extent, for oligodendroglial progenitor (O2A) cells, but does not stimulate proliferation of astroglia, Schwann cells, or endoneurial fibroblasts. OTF, unlike platelet-derived growth factor (PDGF), is not an oligodendroglial survival factor. Antibodies against PDGF and basic fibroblast growth factor (bFGF) do not interfere with the accumulation of oligodendroglia induced by OTF. When OTF is given simultaneously with either PDGF or bFGF, there is an additive increase in the numbers of cells of the oligodendroglial lineage.

Animals↗