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Biomedical subjects

L Olson

Publications and source records attributed to L Olson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Partial venous thrombosis of the pancreatic allografts after simultaneous pancreas-kidney transplantation.

Despite new advances in transplantation, complete venous thrombosis (VT) of the pancreas after simultaneous pancreas kidney (SPK) transplantation usually results in graft loss. Data are limited regarding the outcome and treatment of partial VT of the pancreas allograft. From July 1994 to December 1999, 126 patients with IDDM/end-stage renal disease underwent SPK with systemic bladder drainage at the University of Miami. We retrospectively reviewed our experience regarding the outcome and treatment options of partial VT of the pancreas allografts. From July 1994 to April 1997, partial VT was not seen in the first 66 SPK patients induced with anti-CD3 rnAb and oral or intravenous (i.v.) tacrolimus (TAC) in the operating room. From May 1997 to June 1999, 14 (29%) out of 48 patients had VT. These cases were identified following the i.v. use of TAC with anti-IL-2R antibody-induction therapy (7/15) or without (7/33). Partial thrombosis of the splenic vein (PTSV) was documented in 10 patients, 2 had complete thrombosis of the splenic vein (CTSV), 1 had partial thrombosis of the superior mesenteric vein (PTSMV), and 1 patient had PTSV and PTSMV. These were identified incidentally during routine color Doppler ultrasonography (CDU). None of these SPK recipients demonstrates a change in clinical parameters. The first 8 patients were systemically heparinized, followed by oral anticoagulation, except 1 patient with CTSV. He progressed to complete thrombosis of the pancreas allograft and was treated with percutaneous thrombectomy and urokinase infusion, followed by heparinization and oral anticoagulation. One patient required exploration for bleeding. In an attempt to reduce the morbidity of heparinization, we treated the next 6 patients with PTSV with aspirin followed by serial CDU. All 14 patients had preservation of the endocrine and exocrine pancreatic functions. CDU showed resolution with recanalization of the thrombosed vein(s). From July 1999 to December 1999, 12 SPK recipients were administered TAC orally with or without induction therapy with anti-IL-2R antibody. So far, in this group, VT has not been identified. In summary, a total of 14 out of 126 patients (11%) had isolated VT with a mean follow-up of 36.4 months. Based on our experience, we suggest that extensive VT after pancreas transplantation, including splenic and superior mesenteric VT, be treated with heparin and subsequent oral anticoagulation for 3 months. For more limited, partial splenic VT, aspirin may be sufficient. Follow-up CDU is critical for a successful outcome. The i.v. use of TAC appears to be a risk factor for the increased incidence of VT. Currently, using IL-2rmAb as induction, TAC is started orally on postoperative days 3 or 4 and aspirin on postoperative day 2.

Adult↗
PubMed2000

Running and cocaine both upregulate dynorphin mRNA in medial caudate putamen.

Physical activities such as long-distance running can be habit forming and associated with a sense of well-being to a degree that justifies comparison with drug-induced addictive behaviours. To understand molecular similarities and dissimilarities controlling these behaviours in humans we compared the effects of running in running wheels to the effects of chronic cocaine or morphine administration on mRNA levels in brain reward pathways in the inbred Fischer and Lewis rat strains. These strains are both inbred from the Sprague-Dawley strain; Lewis rats display a higher preference towards addictive drugs and running than do Fischer rats. After chronic cocaine or running a similar increase of dynorphin mRNA in medial caudate putamen was found in the Lewis rat, suggesting common neuronal adaptations in this brain region to both cocaine and running. Fischer and Lewis rats both responded to cocaine with increased dynorphin mRNA levels in medial caudate putamen. However, only Lewis rats increased dynorphin mRNA after running, possibly reflecting the much higher degree of running by the Lewis strain as compared to the Fischer strain. Moreover, the running-induced upregulation of dynorphin mRNA was blocked by the opioid receptor antagonist naloxone. We suggest that running increases dynorphin mRNA by a mechanism that involves endogenous opioids. The voluntary wheel-running model in rats might be used to study natural reward and compulsive behaviours and possibly also to screen candidate drugs for treatment of compulsive disorders.

Analgesics, Opioid↗
PubMed2000

Repeat ambulance use by pediatric patients.

OBJECTIVE: To compare pediatric patients transported by ambulance on more than one occasion (repeat) with those transported only once. METHODS: The authors analyzed pediatric (patient < 21 years old) transports for 1992-1995 by the ambulance service that provides 99% of transports for a non-innercity metropolitan area. Repeat transports were compared with single transports with regard to patient age, gender, chief complaint, and payment source. RESULTS: There were 17,448 transports involving 15,168 patients. Nearly half (49.0%) of the repeat transports involved patients in the oldest age category, 17 to 20.9 years, contrasted with 38.0% of single transports (p < 0.00001). Females comprised 51.4% of the repeat transports and 48.5% of the single transports (p = 0.0008). Traumatic complaints accounted for one-third (33.0%) of the repeat transports and half (51.1%) of the single transports (p < 0.0001). Chief complaints of the patients with repeat transports were more likely to be seizure, assault, abdominal pain, and respiratory problems, and less likely to be falls and motor vehicle-related complaints, than chief complaints of the patients with single transports (p < 0.0001). More than one-third (39.0%) of the repeat transports were funded by Medicaid, in contrast with 19.8% of the single transports (p < 0.0001). CONCLUSIONS: Compared with single transports, repeat transports were more likely to involve patients more than 16 years of age, female, and with a chief complaint of seizure, assault, abdominal pain, or respiratory distress, and more likely to be funded by public insurance (Medicaid). Repeat pediatric transports warrant further investigation. This information may be useful in designing interventions targeted at reducing emergencies and hence ambulance use.

Adolescent↗
PubMed2000

Transport and reaction at endothelial plasmalemma: distinguishing intra- from extracellular events.

The pulmonary endothelium is a chemical reactor that modifies blood composition in several ways, including reduction of the oxidized forms of certain redox active substances in the blood. The physiological functions of the transplasma membrane electron transport systems involved in the latter are not fully understood, but an argument is made that they are involved in antioxidant defense. In addition, the experimental approaches used to characterize the process, including studies at whole organ, cell culture, and subcellular levels, along with the use of mathematical modeling, may be representative of the physiome concept wherein a goal is the integration of information obtained at all levels of biological organization. In this article, separation of intra- and extracellular events involved in the disposition of redox active probes within the lungs is the particular example.

Animals↗
PubMed2000

A review of behavioral treatments used for Lesch-Nyhan syndrome.

Lesch-Nyhan syndrome is a genetic disorder resulting in hyperuricemia, choreoathetosis, mental retardation, and self-mutilation. The most salient feature of this disorder is the self-injurious behavior (SIB). Although the utility of behavioral interventions with SIB has been well documented, behavioral interventions with Lesch-Nyhan syndrome have been limited in number and long-term success. This article reviews the behavioral treatments that have been used in treating individuals with Lesch-Nyhan syndrome and discusses the strengths and weaknesses of these methods. Suggestions for future directions in the use of behavioral interventions for controlling SIB in Lesch-Nyhan syndrome are provided.

Behavior Therapy↗
PubMed2000

Bronchoalveolar lavage cytology and hematology: a comparison between high and low health status pigs at three different ages.

Bronchoalveolar lavages (BALs) were performed with a bronchoscope on 5- and 7.5-week-old, anesthetized, high health status pigs (n = 14). At 10 weeks of age, pigs (n = 28) were necropsied, lungs were removed, and BAL samples were collected from the right diaphragmatic lobe with a modified 12-Fr (4-mm) Foley catheter. Peripheral blood was sampled from all pigs (n = 28) before each BAL procedure. Peripheral blood and BAL samples were collected according to a similar study design at 5, 7.5, and 10 weeks of age from 12 low health status pigs, which were raised according to standard farm procedures (n = 6) or as segregated early weaned pigs (n = 6). Bronchoalveolar lavage cytology and hematologic 95% confidence intervals were determined for 5-, 7.5-, and 10-week-old high (group A) and low health status pigs (groups B and C). The results were compared between the different groups. Repeated BALs were easily performed in all pigs, making this an additional tool for evaluation of respiratory health. Total numbers of cells and neutrophils in peripheral blood and BAL samples were greater in low health status pigs than in high health status pigs. Hematologic results paralleled the findings in BAL fluid. Segregated early weaning of low health status pigs in a less challenging environment mainly reduced the number of neutrophils in BAL samples and peripheral blood.

Age Factors↗
PubMed1999

Fate of mesencephalic AHD2-expressing dopamine progenitor cells in NURR1 mutant mice.

The orphan nuclear receptor NURR1 was previously demonstrated to be required for the generation of mesencephalic dopamine (DA) cells. However, even in the absence of NURR1, which is normally expressed as cells become postmitotic, neuronal differentiation is induced and expression of several genes detected in developing dopamine cells appears normal during early stages of development. These include the homeobox transcription factors engrailed and Ptx-3 as well as aldehyde dehydrogenase 2, here defined as the earliest marker identified in developing DA cells, expressed already in mitotic DA progenitors. We have used the expression of these dopaminergic markers, retrograde axonal tracing, and apoptosis analyses to study the fate of the DA progenitor cells in the absence of NURR1. We conclude that NURR1 plays a critical role in the maturation, migration, striatal target area innervation, and survival of differentiating mesencephalic DA cells.

Aldehyde Dehydrogenase↗
PubMed1999

Microangiopathy in kidney and simultaneous pancreas/kidney recipients treated with tacrolimus: evidence of endothelin and cytokine involvement.

BACKGROUND: In the past 3 years, three transplant recipients [one kidney, two simultaneous pancreas/kidney (SPK)] developed a thrombotic thrombocytopenic purpura-like clinical syndrome. This was characterized by an abrupt fall in the hematocrit and platelet count with evidence of hemolysis (fragmented red blood cells and schistocytes) and transplant kidney dysfunction during the first 2 weeks after transplantation. This was also associated with pancreatic dysfunction in the two SPK recipients. In all three patients, elevated tacrolimus levels (>24 ng/ml) occurred. METHODS: Serum cytokine and endothelin levels were determined retrospectively from stored (-70 degrees C) sera. RESULTS: In each case tacrolimus was discontinued, and treatment with plasmapheresis, fresh frozen plasma, steroids, and OKT3 was begun. The clinical courses varied from mild (one patient), to moderate (one patient), to severe (one patient), complicated with seizures and coma. Each patient responded clinically and ultimately was converted to cyclosporine A, and/or mycophenolate mofetil. These clinical events were associated with a rise in serum levels of endothelin and several cytokines. Levels of endothelin were elevated at 209+/-137 pg/ml, particularly in the severe episode where peak levels reached 480 pg/ml (normal 0-20 pg/ml). Peak levels of IL-8 (104+/-36 pg/ml), interleukin- (IL) 10 (238+/-105 pg/ml), and/or IL-12 (306+/-119 pg(ml) mean+/-SE, occurred during or before the clinical event. Serum levels of tumor necrosis factor-a and interferon-gamma were elevated in 2 patients while levels of IL-2, IL-4, and IL-6 were not elevated during the acute phase. CONCLUSIONS: These data are consistent with a mechanism of microangiopathy involving endothelial cell injury (associated with tacrolimus treatment), and accompanied by cytokines (IL-10, IL-12, tumor necrosis factor-a, interferon-gamma) that affect expression of adhesion molecules, chemokines (IL-8) that direct the influx of white blood cells and endothelins that may exacerbate underlying hypertension and increase shear force-related red blood cell destruction.

Adult↗
PubMed1999

Addiction-prone Lewis but not Fischer rats develop compulsive running that coincides with downregulation of nerve growth factor inducible-B and neuron-derived orphan receptor 1.

We have examined the effects of chronic voluntary running for 30 d on the levels of nerve growth factor inducilble-B (NGFI-B) and neuron-derived orphan receptor 1 (NOR1) mRNAs in Fischer and Lewis rats. The aim was to compare the addiction-prone Lewis rat strain to the Fischer strain in a plausible model for natural reward. The Lewis strain ran markedly more than the Fischer strain, as indicated by the length of running per day when given free access to running wheels. Both strains progressively increased their amount of daily running. By day 14, Lewis rats had reached a maximal level corresponding to 10 km/d, which slowly decreased to approximately 8 km/d. Fischer rats ran considerably less, averaging approximately 1. 5 km/d by day 30. After 30 d of running, levels of mRNA encoding NGFI-B and Nor1 were decreased in cerebral cortex in Lewis but not Fischer rats. The downregulation of NGFI-B mRNA in Lewis rats could not be attenuated by the opioid receptor antagonist naloxone. Instead, naloxone by itself downregulated NGFI-B in striatum and cerebral cortex in both strains. In contrast, naloxone had no effect on Nor1 mRNA levels, although the running-induced downregulation of Nor1 was, in most cases, attenuated by naloxone. Data from the present study suggest that the same genetic factors contributing to the drug addiction-prone behavior of Lewis rats also control the excessive running behavior and that this coincides with downregulation of transcription factors of the NGFI-B family.

Animals↗
PubMed1999

Health indicators and intimate partner violence among women who are members of a managed care organization.

BACKGROUND: There have been no population-based studies estimating the prevalence of intimate partner violence (IPV) in an insured population. There is also little information on how well routinely collected health status information predicts IPV risk. Many women now obtain health care from providers who are members of a managed care organization (MCO). To justify efforts to routinely screen for IPV, it is essential to know the prevalence of IPV in this growing population and to identify correlates of IPV among female MCO members. METHODS: A telephone survey with questions on health status, behavioral risk factors, preventive services use, and the Conflict Tactics Scale was completed by 2,415 female members of a New Mexico MCO. RESULTS: Overall, 13.5% of respondents reported experiencing major verbal aggression and 6.7% reported experiencing physical aggression. Younger age, degree of sadness, and inability to handle stress, and a perception of a poorer general health status were significantly associated with major verbal aggression. Race/ethnicity, degree of sadness, and average number of drinks consumed at one sitting were significantly associated with physical aggression. CONCLUSIONS: There is a low but important annual prevalence of IPV among female members of a MCO that occurs across all variables studied. This information is needed to develop appropriate screening protocols and interventions in this population.

Adult↗
PubMed1999

Transplantation of islets of Langerhans in patients with insulin-requiring diabetes mellitus undergoing orthotopic liver transplantation--the Miami experience.

Most patients with cirrhosis of the liver have detectable insulin resistance. In 60-80% of patients with cirrhosis, impaired glucose tolerance can be uncovered; approximately 20% of these patients eventually develop overt diabetes. Theoretically, insulin resistance and glucose intolerance could be improved or reversed by orthotopic liver transplantation alone or in association with a simultaneous transplant of pancreatic islet cells from the same donor. To investigate these possibilities we initiated a pilot study of simultaneous liver and pancreatic islet cell transplantation in seven patients with diabetes and liver cirrhosis. Donor bone marrow cells were also infused to enhance the acceptance of the grafts. Seven patients who received only orthotopic liver transplantation and donor bone marrow cells were used as historical controls. The preliminary results of this pilot trial suggest that islet cell transplantation in conjunction with orthotopic liver transplantation improves glucose metabolism in patients with liver cirrhosis in association with reduced insulin requirements and HbA1c levels. These results were evident in spite of pre- and post-transplant basal C-peptide levels that were unchanged. Further evaluation of the effects of orthotopic liver transplantation with or without islet cell transplantation will require a randomized prospective trial including accurate metabolic evaluation with the euglycemic insulin clamp technique.

Adolescent↗
PubMed1999

Deprived of habitual running, rats downregulate BDNF and TrkB messages in the brain.

To study possible effects of physical training on the expression of neurotrophic factors and their receptors in the brain, we used a rat strain (spontaneously hypertensive rat, SHR), known to spontaneously run up to 20 km/night. We show that such long-distance running affects the brain-derived neurotrophic factor (BDNF) and TrkB system in hippocampus, and in particular that abrupt deprivation of habitual running leads to long-lasting decreases of BDNF/TrkB expression in hippocampus. Quantitative in situ hybridization demonstrates that running increases the expression of mRNA coding for BDNF and its high affinity receptor TrkB in hippocampus in a running length dependent manner. In addition, we show that an abrupt interruption of prolonged spontaneous exercise decrease expression of mRNA encoding BDNF and TrkB in certain hippocampal areas and that this decrease lasts at least 10 days. This down-regulation was most prominent in medial cornu ammonis 3 (CA3M). Several other trophic factors and receptors were investigated, including NGF, NT3, GDNF, trkC and p75. For these other probes investigated, no robust changes in mRNA expression were noted. Areas examined included sensorimotor cortex and hippocampus. For RET, p75, NT3, TrkB and BDNF we also examined the spinal cord without detecting any robust changes. We conclude that spontaneous running as well as its abrupt termination, leads to area-specific and trophic factor-specific changes in hippocampus.

Animals↗
PubMed1999

Guns, alcohol, and intimate partner violence: the epidemiology of female suicide in New Mexico.

Suicide is among the leading causes of death in the United States, and in women the second leading cause of injury death overall. Previous studies have suggested links between intimate partner violence and suicide in women. We examined female suicide deaths to identify and describe associated risk factors. We reviewed all reports from the New Mexico Office of the Medical Investigator for female suicide deaths occurring in New Mexico from 1990 to 1994. Information abstracted included demographics, mechanism of death, presence of alcohol/drugs, clinical depression, intimate partner violence, health problems, and other variables. Annual rates were calculated based on the 1990 census. The New Mexico female suicide death rate was 8.2/100,000 persons per year (n = 313), nearly twice the U.S. rate of 4.5/100,000. Non-Hispanic whites were overrepresented compared to Hispanics and American Indians. Decedents ranged in age from 14 to 93 years (median = 43 years). Firearms accounted for 45.7% of the suicide deaths, followed by ingested poisons (29.1%), hanging (10.5%), other (7.7%), and inhaled poisons (7.0%). Intimate partner violence was documented in 5.1% of female suicide deaths; in an additional 22.1% of cases, a male intimate partner fought with or separated from the decedent immediately preceding the suicide. Nearly two-thirds (65.5%) of the decedents had alcohol or drugs present in their blood at autopsy. Among decedents who had alcohol present (34.5%), blood alcohol levels were far higher among American Indians compared to Hispanics and non-Hispanic Whites (p = .01). Interpersonal conflict was documented in over 25% of cases, indicating that studies of the mortality of intimate partner violence should include victims of both suicide and homicide deaths to fully characterize the mortality patterns of intimate partner violence.

Adolescent↗
PubMed1999

Role of retinoids in the CNS: differential expression of retinoid binding proteins and receptors and evidence for presence of retinoic acid.

Retinoic acid (RA), a retinoid metabolite, acts as a gene regulator via ligand-activated transcription factors, known as retinoic acid receptors (RARs) and retinoid X receptors (RXRs), both existing in three different subtypes, alpha, beta and gamma. In the intracellular regulation of retinoids, four binding proteins have been implicated: cellular retinol binding protein (CRBP) types I and II and cellular retinoic acid binding protein (CRABP) types I and II. We have used in situ hybridization to localize mRNA species encoding CRBP- and CRABP I and II as well as all the different nuclear receptors in the developing and adult rat and mouse central nervous system (CNS), an assay to investigate the possible presence of RA, and immunohistochemistry to also analyse CRBP I- and CRABP immunoreactivity (IR). RXRbeta is found in most areas while RARalpha and -beta and RXRalpha and -gamma show much more restricted patterns of expression. RARalpha is found in cortex and hippocampus and RARbeta and RXRgamma are both highly expressed in the dopamine-innervated areas caudate/putamen, nucleus accumbens and olfactory tubercle. RARgamma could not be detected in any part of the CNS. Using an in vitro reporter assay, we found high levels of RA in the developing striatum. The caudate/putamen of the developing brain showed strong CRBP I-IR in a compartmentalized manner, while at the same time containing many evenly distributed CRABP I-IR neurons. The CRBP I- and CRABP I-IR patterns were closely paralleled by the presence of the corresponding transcripts. The specific expression pattern of retinoid-binding proteins and nuclear retinoid receptors as well as the presence of RA in striatum suggests that retinoids are important in many brain structures and emphasizes a role for retinoids in gene regulatory events in postnatal and adult striatum.

Animals↗
PubMed1999

Early outpatient preoperative anesthesia assessment: does it help to reduce operating room cancellations?

UNLABELLED: Increased understanding of the high cost associated with operating room (OR) cancellations has led to efforts by healthcare providers to decrease case cancellations on the day of surgery. To investigate whether preoperative evaluations within 24 h of surgery were associated with more frequent OR cancellations than those completed 2-30 days before surgery, we prospectively studied OR cancellations for 3 mo. Of the 529 patients in the study, 166 were seen within 24 h of surgery (standard group), and the remaining 363 patients were seen 2-30 days before surgery (early group). There were 70 OR cancellations on the day of surgery, and the largest single group of cancellations was related to administrative problems. The standard group and the early group were similar in terms of gender, age, ASA physical status, and percentage of patients undergoing major surgery. The OR cancellation rates were also comparable between groups: 13.3% for the standard group and 13.2% for the early group. These data suggest that patients can be evaluated in an outpatient preoperative evaluation clinic in a timeframe that is convenient for the patient without adversely affecting the cancellation rate on the day of surgery. IMPLICATIONS: The operating room cancellation rate for outpatients evaluated 2-30 days before surgery was compared with the cancellation rate for outpatients who received their anesthesia evaluation within 24 h of surgery. Because both groups had similar rates, outpatients may be seen at a convenient time without adversely affecting operating room cancellations.

Ambulatory Surgical Procedures↗