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Biomedical subjects

S H Pedersen

Publications and source records attributed to S H Pedersen.

At least 19 recordsLinked to original sources
PubMed2004

Different cerebrovascular effects of medroxyprogesterone acetate and norethisterone acetate in the New Zealand White rabbit.

OBJECTIVE: The lack of a cardioprotective effect of hormone replacement therapy (HRT), as suggested by the Heart and Estrogen/progestin Replacement Study (HERS) and Women's Health Initiative (WHI) may in part be explained by the progestin used. The aim of this study was to elucidate the effect of different progestins on cerebrovascular reactivity in an animal model. METHODS: Fifty-six ovariectomized New Zealand White rabbits were randomized into seven groups receiving hormone treatment for 4 weeks: medroxyprogesterone acetate (MPA) (10 mg/day); norethisterone acetate (NETA) (3 mg/day); conjugated equine estrogens (CEE) (1.25 mg/day); 17beta-estradiol (E2) (4 mg/day); MPA + CEE (10 mg/day + 1.25 mg/day); NETA + E2 (3 mg/day + 4 mg/day); or placebo. Segments from the basilar and posterior cerebral arteries were mounted in myographs for tension recordings. Concentration-response curves to potassium, acetylcholine, sodium nitroprusside, L-NAME (N(omega)-nitro-L-arginine methyl ester), calcium and endothelin-1 were established. RESULTS: Treatment with MPA caused a significant increase in vasoconstriction, expressed as E(max) (mN/mm, mean +/- SEM; p < 0.05), in response to potassium (3.18 +/- 0.19 vs. 2.47 +/- 0.19) and calcium (4.00 +/- 0.22 vs. 3.34 +/- 0.14) in the posterior cerebral artery, and to endothelin-1 (6.88 +/- 0.69 vs. 5.22 +/- 0.30) in the basilar artery, when compared with NETA. This difference was neutralized in the groups receiving the combined treatment of MPA + CEE and NETA + E2. No overall differences were seen between CEE and E2. CONCLUSIONS: In rabbit cerebral arteries, MPA treatment causes a higher development in arterial tension compared with NETA, indicating that different progestins may display different cerebrovascular effects. However, when accompanied by estrogens, as in the case of HRT, this difference is eliminated.

Acetylcholine↗
PubMed2003

Acute effects of tibolone on cerebral vascular reactivity in vitro.

OBJECTIVE: To evaluate the acute effects of tibolone and its metabolites on cerebral vascular reactivity in vitro. METHODS: Ring segments of the posterior cerebral artery from female rabbits were mounted in myographs for isometric tension recordings. Concentration-response curves with tibolone, 3alpha-OH-tibolone, 3beta-OH-tibolone, Delta(4) isomer and 17beta-estradiol were obtained before and after addition of the NO blocker N(omega)-nitro-L-arginine methyl ester (L-NAME, 10(-4) mol/l) or the potassium-channel blocker tetraethylammonium chloride (TEA, 10(-2) mol/l). Additionally, the effects of the hormones on the concentration-response curves with calcium were examined. RESULTS: Tibolone and its metabolites induced a concentration-dependent relaxation comparable to that of 17beta-estradiol (area under the curve (AUC); tibolone vs. 17beta-estradiol: 242 vs. 251; p < 0.05, analysis of variance). L-NAME increased the AUC for all substances compared with controls (p < 0.05, Student's t test), except for 17beta-estradiol. Preincubation with TEA induced no changes. The concentration-dependent contraction curves with calcium were shifted rightward by all hormones. CONCLUSIONS: The study demonstrates that the acute relaxation induced by tibolone and its metabolites in cerebral arteries in vitro is comparable to that with 17beta-estradiol, and seems to be mediated by inhibition of voltage-gated calcium channels and possibly partly by a nitric oxide-dependent mechanism.

Animals↗
PubMed2001

ICD-10 criteria for depression in general practice.

BACKGROUND: The rate of recognition of depressive disorder in general practice is reported to be low. Current classification systems, i.e. ICD-10 and DSM-III-R, and DSM-IV with operational diagnostic criteria, have led to greater agreement concerning the diagnosis of depressive disorder. The aim of this study was to assess the applicability and validity of the ICD-10 criteria for depression in general practice in Denmark. METHODS: After a 1-day training course in the ICD-10 criteria for depression, ten general practitioners, during an 8-week period assessed all patients aged 18 or older for depressive symptoms in accordance with the ICD-10 criteria. RESULTS: Among a total of 3505 consultations, 116 patients (3.3%) met the criteria for a depressive episode. Of these, 80 (68.8%) accepted to be reinterviewed by a psychiatrist, who confirmed the diagnosis of depressive disorder in 57 of the 80 patients (71.3%). LIMITATIONS: The number of 'false negative' cases are unknown in the study. CONCLUSION: The ICD-10 criteria for depression seem to be appropriate and valid in general practice.

Adult↗
PubMed2000

Pituitary adenylate cyclase-activating peptide stimulates acute progesterone production in rat granulosa/Lutein cells via two receptor subtypes.

Pituitary adenylate cyclase-activating peptide (PACAP) is transiently expressed in ovarian granulosa/lutein cells from eCG/hCG-treated rats, and in vitro immunoneutralization of endogenously released PACAP inhibits acute progesterone secretion and subsequent luteinization in such cells. This suggests that PACAP mediates locally some of the effects of the LH surge, but the putative PACAP receptor(s) involved in such an auto or paracrine activity is presently unknown. Reverse-transcription polymerase chain reaction with specific primers to the three cloned PACAP-binding receptors called PAC(1), VPAC(1), and VPAC(2) demonstrated both PAC(1) and VPAC(2) mRNA in extracts from preovulatory follicular cells. Radioligand-binding assays revealed the presence of high-affinity binding sites with characteristics of these two receptors on the intact cells, and autoradiography demonstrated that the binding was restricted to a minor proportion of the follicular cells as well as the oocytes. Pituitary adenylate cyclase-activating peptide and vasoactive intestinal peptide (VIP) dose-dependently stimulated cAMP accumulation and acute progesterone accumulation. Forskolin and db-cAMP also stimulated acute progesterone accumulation, and the protein kinase A inhibitor H89 dose-dependently inhibited peptide induced acute progesterone accumulation, suggesting involvement of cAMP and the protein kinase A pathway in the process. In conclusion, two of the three PACAP binding receptors are present on preovulatory follicular cells and are involved in the effects of PACAP on acute progesterone production. The data provide further evidence to establish PACAP as an auto- or paracrine regulator of LH-induced acute progesterone production in rat preovulatory follicles.

Animals↗
PubMed1998

Late allergy-like reactions following vascular administration of radiography contrast media.

PURPOSE: To compare the frequency of allergy-like reactions in adults following vascular injection of iohexol and iopentol versus other contrast media (CMs), with emphasis on late reactions. MATERIAL AND METHODS: Thirty-two trials involving a total of 2,656 patients in the European clinical development programmes for iohexol and iopentol were retrospectively evaluated. The number of patients experiencing late allergy-like reactions, immediate allergy-like reactions, and both types of reaction were pooled separately. Late was defined as time of onset being 60 min or more after the first injection of CM. RESULTS AND CONCLUSION: After vascular administration of iohexol and iopentol, 0.52% (0.44% and 0.68% respectively) of the patients experienced a late allergy-like reaction. The same frequency was reported for immediate allergy-like reactions. After administration of ionic CMs, the frequency of late allergy-like reactions was in the same range (0.42%) as for non-ionic CMs, but the frequency of immediate allergy-like reactions was much higher (6.99% vs 0.52%). Our results are in the same range as those reported by other authors. No serious adverse reactions were reported in the 32-trial series.

Contrast Media↗
PubMed1994

The spectrum of bile duct complications in pediatric liver transplantation.

It has been noted that reduced-size liver transplants are associated with increased rates of biliary complications, and it has been suggested that some of these complications can be handled nonoperatively. In a 6-year period, 91 orthotopic liver transplants were performed in 77 children. The medical records were reviewed to analyze the effect of reduced-size grafts on the incidence of bile duct complications and to investigate the utility of interventional radiology techniques for treatment. Forty-two children received 47 whole-organ transplants, and 35 children received 44 reduced-size transplants. The median age and weight were greater for children receiving whole-organ transplants (age, 4.25 years; weight, 16 kg) than for those receiving reduced-size grafts (age, 1.0 year; weight, 8 kg). The overall incidence of bile duct complications was 19.5% (n = 15). The incidence was not different between the whole organ group (17%) and the reduced-size group (16%). Four of the children with bile duct complications had associated hepatic artery thrombosis, two of whom had another transplant. Complications included anastomotic stricture (n = 6), anastomotic leak (n = 5), intraparenchymal biloma (n = 3), and multiple strictures (n = 1). Twelve of 15 children presented within 3 months of transplantation. Six children had initial percutaneous drainage or placement of transanastomotic stents (external). Operative repair was eventually required for all 15 children, three of whom received a second transplant. There was a 40% incidence of cytomegalovirus infection involving the liver or extrahepatic bile ducts near the time of presentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Accelerated surgical stay programs. A mechanism to reduce health care costs.

OBJECTIVE: To increase cost-efficiency while maintaining the standard of medical care, an accelerated surgical stay program for patients having breast surgery was instituted. SUMMARY BACKGROUND DATA: In the past 20 years, annual health care costs have soared and now comprise 12.2% of the United States gross national product. The annual inflation rate of almost 11% has prompted third-party payers to scrutinize hospital costs as hospitals now consume 38% of health care costs. METHODS: A multidisciplinary task force was formed to analyze and reduce lengths of stay for breast surgeries and to standardize clinical protocols to address ensuing issues. RESULTS: After 1 year, this prospective study found a 39% decrease in average length of stay and a 22% increase in patient volume. This was also accompanied by a low incidence of surgical complications. Through information obtained from 373 consecutive patients through telephone surveys and questionnaires, the Center for Cost-Effective Care reported high patient acceptance and satisfaction. CONCLUSIONS: As a management strategy, accelerated surgical stay programs increase operating efficiency and reduce medical care costs without compromising quality of patient care. Success of this program was attributed to support from senior management, expansion of available educational resources for patients, and to a carefully planned transition from the program's developmental to its operational phase.

Breast Neoplasms↗
PubMed1994

Sequelae one year after meningococcal disease.

Of 99 consecutive patients with meningococcal disease, 6 died during the acute stage. The 93 survivors were examined one year after hospitalization. 21 (40%) of the adults and 6 (15%) of the children had definite sequelae, and an additional 27% and 11% possible sequelae. 6 adults (12%) and 1 child (2%) had definite neurological sequelae. Electroencephalography (EEG) abnormalities were observed in 7 adults (14%) and 2 children (5%). Epileptogenic activity was present in 3 of these, but none had experienced seizures. 8 adults (19%) and 5 children (14%) had sensorineural hearing loss or impaired vestibular function. Cerebral computerized tomography (CT) scan showed definite and possible abnormalities in 1 (3%) and 6 (18%), respectively, of the 34 patients tested. Neuropsychological tests were performed in 9 patients, 2 of these showed definite impairment. The frequency of neurological abnormalities was higher than in many previous studies, probably reflecting the more comprehensive examinations performed in the present study. However, only 3 patients had serious sequelae. The results suggest that the occurrence of sequelae after meningococcal disease is related to the severity of the acute disease. This may explain the higher rate of sequelae in adults, who have a higher proportion of seriously ill patients. The presence of meningitis is not required for the occurrence of neurological sequelae.

Adolescent↗
PubMed1994

Induction therapy with OKT3 in pediatric liver-transplant recipients.

The goal of any posttransplant immunosuppressive regimen is to prevent allograft rejection while minimizing infectious complications. We hypothesized that sequential induction immunotherapy using the monoclonal antibody ORTHOCLONE OKT3 (muromonab-CD3) would meet these objectives effectively. We have therefore used such a protocol since July 1988 for all pediatric patients undergoing liver transplantation at Children's Hospital Medical Center of Cincinnati. Initial immunotherapy consisted of OKT3, administered preoperatively and then QD, methylprednisolone, and azathioprine. Cyclosporine was begun on POD 3-5, and OKT3 was discontinued when therapeutic cyclosporine levels were achieved for 48 hours. Rejection has not occurred throughout the lifetime of the allograft in 55% of long-term survivors. In the 28 patients who experienced rejection episodes, 71% had a single episode, 21% had two episodes, and 7% had a single episode, 21% had two episodes, and 7% had more than two. Rejection occurring after more than 120 days was invariably associated with noncompliance or subtherapeutic cyclosporine levels. The use of an OKT3-based sequential induction protocol resulted in a decreased incidence of acute rejection. Renal function was preserved, and the incidence of infection was not increased. Long-term outcome analysis of this protocol shows excellent patient survival and the near absence of late or chronic rejection.

Adolescent↗
PubMed1992

Hepatobiliary scintigraphy in pediatric liver transplant recipients.

The clinical usefulness of hepatobiliary scintigraphy was evaluated in pediatric liver transplant recipients. One hundred fifteen hepatobiliary scintigraphic studies were performed in 30 patients who received 22 whole liver and 16 segmental grafts. Parameters that were useful in predicting an adverse outcome were failure to visualize excreted radiopharmaceutical at or beyond the biliary anastomosis on a study performed within 24 hours after transplant, and persistent or increasing delay in the time of visualization of excreted radiopharmaceutical. Abnormalities of liver uptake and excretion were seen in rejection, but they were also seen in patients who remained well without rejection or parenchymal disease. Significant biliary leaks were identified in the three cases in which they were known to be present. In liver transplant recipients, hepatobiliary imaging is useful in predicting graft survival and identifying biliary leaks.

Adolescent↗
PubMed1992

Monoethylglycinexylide formation in assessing pediatric donor liver function.

Lidocaine metabolism to monoethylglycinexylide (MEGX) has been described as a novel method to assess liver function in adult transplant donors and recipients. While this assay appears to offer a number of advantages over existing liver function tests, limited work has been done to evaluate its potential in the pediatric population. This study evaluated MEGX formation in potential pediatric liver donors (n = 35) and a control group of children (n = 16). The mean MEGX formation was significantly higher in pediatric donors than in the control group (156 +/- 62 vs 106 +/- 33 ng/ml, p < 0.05). No correlation with age, total bilirubin, liver transaminases, or alkaline phosphatase could be made within each group. Significant differences in MEGX levels were noted when each group was compared to its adult counterpart. Both pediatric donors and controls had greater mean MEGX formation than has been reported for adult donors and controls (156 +/- 62 vs 127 +/- 61 ng/ml, p < 0.05 and 106 +/- 33 vs 72 +/- 36 ng/ml, p < 0.05, respectively). Drugs that alter lidocaine pharmacokinetics and their potential influence on MEGX formation were evaluated in the pediatric donor group. Donors exposed to hepatic enzyme-inducing drugs had a higher mean MEGX formation (187 +/- 60 vs 146 +/- 63 ng/ml). No significant differences were noted between donors receiving and not receiving vasopressors. In conclusion, the significant differences between pediatric and adult MEGX formation should be noted when establishing reference or normal ranges for this diagnostic test. Furthermore, concomitant drug therapy may significantly alter MEGX formation.

Adult↗
PubMed1992

Liver transplantation in children.

Children with end-stage liver disease now have a greater chance of survival through treatment with hepatic transplantation. This article reviews the pediatric liver transplantation process, including selection and evaluation of candidates, operative procedures, postoperative complications, and long-term survival.

Biliary Atresia↗
PubMed1992

Current issues in profiling quality of care.

Profiling provider performance for the assessment of quality involves a number of issues related to selection of appropriate quality measures, subsequent data collection and analysis, and selection of standards of comparison. This article emphasizes the limitations of current data systems for this purpose and discusses hierarchical modeling as the optimal analytic approach for analyzing resulting data. Mention is made of the difficulties of achieving large enough sample sizes for statistical significance at the individual provider level. Finally, the article discusses feasible options for profiling quality.

Data Collection↗
PubMed1991

[From psychiatric hospitals to local municipal departments. The county of Vejle 1973-1987].

On April 1, 1976 the Danish State handed over the responsibility for treatment of psychiatric patients to the counties. None of the state hospitals were situated in the county of Vejle. The changes of the admission pattern of the inhabitants of Vejle county aged 15+ years during the years from 1973 to 1987 are described. The annual bed occupancy per 1,000 inhabitants decreased markedly during the period (from 829 in 1973 til 366 in 1986) while the admission rates were relatively stable. Vejle county has successfully reduced the number of admissions to mental hospitals in other counties, but was, however, still not self-sufficient in 1987. The decrease in bed occupancy was significant in the groups of schizophrenia, manic-depressive psychosis, organic states, neurosis, alcohol and drug addiction, while in the group of other psychoses and other conditions the decrease was not significant. In the group of personality disorder the bed occupancy increased, but not significantly.

Bed Occupancy↗
PubMed1991

Selection criteria for liver transplant donors.

As the number of successful liver transplants has increased, the demand for donors has outpaced the supply. Approximately 25% of patients die awaiting an appropriate donor. Current criteria for assessing potential donors need to be closely examined. Fifty-six potential donors were evaluated by our transplant team by utilizing standard liver function tests (LFT's)-SGOT, SGPT, bilirubin. Additionally, a lidocaine metabolism test was performed by giving a 1 mg/kg IV dose of lidocaine over 1 minute and measuring the accumulation of the major metabolite monoethylglycinxylidide (MEGX) at 15 minutes by fluorescent polarization immunoassay (Abbott Diagnostics, Abbott Park, IL). Previous work has suggested that a MEGX less than 50 ng/mL is associated with initial non-function. Thirty-four donors were transplanted (group I) and all had initial function (all MEGX values were greater than 50). Twenty-two donors (39%) were judged unacceptable (group II) by our transplant team and by outside centers based upon one of the following criteria: II A) elevated LFT's--8, 11 B) donor age--5, II C) donor instability--4, II D) no available recipient--3, II E) miscellaneous--2. Standard LFT's were not statistically different in the donors used and in those not used when excluding category II A. Six of seven donors excluded in group I had acceptable MEGX values indicating they may have been transplantable. Ten of 12 patients excluded in groups II B-D had normal LFT's and nine of 12 had acceptable MEGX values indicating they may have been transplantable also. In this era of organ shortage, a reevaluation of donor selection criteria utilizing new tests like MEGX may be necessary to meet the increased need.

Adolescent↗
PubMed1991

Segmental orthotopic hepatic transplantation as a means to improve patient survival and diminish waiting-list mortality.

Pediatric liver transplantation continues to be limited by the availability of suitable liver donors, a factor that restricts programmatic development and ultimately contributes to death on the recipient waiting list. We report the application of segmental liver transplantation as a technique to address both these problems as well as improving the outcome of the child undergoing the transplant procedure. Since 1986, 37 children have undergone orthotopic liver transplantation. Twenty-three children have received whole-organ grafts; 81% survived. Of those receiving whole-organ grafts, 15% had arterial thrombotic complications and 23% required retransplantation. More importantly, 29% of those children listed for transplantation died while waiting for a donor organ to become available, with a mean interval of 1.7 months (range, 2 days to 4.5 months). Since July 1988, segmental liver transplantation has been a component of our therapeutic armamentarium, and of the past 20 liver recipients, 16 have received a left lobe segmental graft. The results of the segmental transplant series have shown striking improvements. First, no child has died while awaiting donor organ availability. Second, segmental liver recipient survival is equivalent to that of whole-organ graft recipients (81%). Third, hepatic arterial thrombosis, especially a problem in high-risk infant transplants, was reduced by this technique (5%). Retransplantation due to graft complications has not increased (21%). These data suggest a vital role for segmental liver transplantation not only as a remedial salvage procedure for the critically ill child, but also as a primary transplant option.

Adolescent↗