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Biomedical subjects

T Patterson

Publications and source records attributed to T Patterson.

At least 19 recordsLinked to original sources
PubMed2004

Bone mineral assessment by dual energy X-ray absorptiometry in children with inflammatory bowel disease: evaluation by age or bone area.

BACKGROUND: Abnormal linear growth and deficient bone mineral acquisition may coexist in children with inflammatory bowel disease (IBD). Traditionally, bone mineral assessment by dual energy x-ray absorptiometry (DXA) involves comparison to age- and gender-matched reference ranges, and these studies in children with IBD show a high prevalence of osteopenia. AIMS: To compare the prevalence of osteopenia using two methods of interpretation; one adjusted for age and gender and the other adjusted for bone size and gender. PATIENTS: Forty-seven patients with Crohn disease (CD) and 26 patients with ulcerative colitis (UC) with a median age of 13.5 years (range, 5.5-18.2 years) were evaluated. METHODS: Lumbar spine (LS) and total body (TB) bone mineral content (BMC) were measured by DXA and converted to bone mineral density (BMD, g/cm) corresponding to BMC divided by the bone area. Age and gender-matched BMD standard deviation scores (SDS) were based on reference data providing age- and gender-matched BMC and bone area. These data also allowed calculation of percentage of predicted bone area for age and gender (ppBone Area) and percentage of predicted BMC for Bone Area (ppBMC). RESULTS: Patients with CD were shorter than those with UC (median height, SDS, -0.9 v 0, P < 0.05). Median ppBone Area for LS and TB for the whole group was 85% (10th centile, 68; 90th centile 99) and 81% (10th centile 66; 90th centile, 97), respectively. The ppBone Area at both sites was directly related to height SDS and BMI SDS (r > 0.5; P < 0.005). Median BMD SDS for LS and TB was -1.6 (10th centile -3.6; 90th centile, -0.2) and -0.9 (10th centile, -2.4; 90th centile, 0.4), respectively. Median ppBMC for LS and TB was 98% (10th centile, 84%; 90th centile, 113%) and 101% (10th centile 94%; 90th centile, 107%), respectively. The ppBMC showed no relationship to ppBone Area (r = 0.1, NS). Failure to account for bone area led to a label of moderate or severe osteopenia in 65% of cases. After adjustment for bone area, the proportion of children with osteopenia fell to 22%. CONCLUSIONS: The data suggest that children with IBD often have small bones for age because they have growth retardation. When DXA data are interpreted with adjustment for bone size, most children were found to have adequate bone mass. Correct interpretation of DXA is important for identifying children who may be at a real risk of osteoporosis.

Absorptiometry, Photon↗
PubMed2001

Health-related quality of well-being in chronically hospitalized patients with schizophrenia: comparison with matched outpatients.

Quantifying the functional consequences of illness in terms of quality of life can enhance our understanding of both mental and physical disorders. However, little is known about the quality of life among older inpatients vs. outpatients with schizophrenia. We present the results of health-related quality of life assessments in 54 middle-aged and elderly long-term inpatients with schizophrenia and a demographically matched outpatient sample. Assessments were performed using the Quality of Well-Being (QWB) scale, along with standard measures of psychopathology and global cognitive impairment. Compared with outpatients, the inpatients had a significantly lower health-related quality of life, as measured by the QWB. In the inpatient and outpatient groups, higher levels of positive symptoms were associated with lower health-related quality of life. Health-related quality of life remained fairly stable among the inpatients who remained hospitalized over 6 months. In both inpatients and outpatients, baseline cognitive status and psychopathology predicted QWB scores at the 6-month follow-up. These findings further support the use of the QWB in severely mentally ill populations; implications for improving health-related quality of life among older patients with schizophrenia are discussed.

Adult↗
PubMed2001

Mechanism of repression of squamous differentiation marker, SPRR1B, in malignant bronchial epithelial cells: role of critical TRE-sites and its transacting factors.

The overexpression of SPRR1B in bronchial epithelium is a marker for early metaplastic changes and the loss of its expression is associated with an irreversible malignant transformation. In the present study, we have used a model system consisting of normal and malignant bronchial epithelial (BE) cells to elucidate the differential transcriptional control of SPRR1B. SPRR1B expression is either detectable or PMA (phorbol 13-myristate 12-acetate) -inducible in several malignant BE cells including squamous, adeno, small and large cell carcinomas. Loss of SPRR1B expression is correlated well with the lack of strong in vivo protein-DNA interactions at the -152 bp promoter, which contains two functional TRE sites. Even though the basal level AP-1 protein DNA binding pattern is different between normal and malignant cells, PMA significantly enhances Jun and Fos binding to the consensus TRE site in both cell types. Intriguingly, the composition of AP-1 protein binding to the -152 to -86 bp SPRR1B promoter is quite different. In untreated cells, SPRR1B promoter is predominantly occupied by JunD and Fra2. PMA significantly induced binding of JunB and Fra1 in normal cells, while JunB and Fra2 bound to TREs in the malignant cells. Overexpression of fra1 in malignant cells significantly enhanced SPRR1B promoter activity. In contrast, overexpression of fra2, but not fra1, strongly reduced both basal and PMA-inducible promoter activities in normal cells. Together, these results indicate that either temporal expression and/or differential activation of AP-1 proteins, especially Fra1 and Fra2, might contribute to the dysregulation of terminal differentiation marker, SPRR1B, expression in various BE cells.

Animals↗
PubMed2001

Actigraphic estimates of circadian rhythms and sleep/wake in older schizophrenia patients.

Twenty-four hour circadian activity rhythms and light-exposure levels of 28 older schizophrenia patients (mean age=58years) were examined using an Actillume recorder. Sleep and wake were scored using the algorithm of the ACTION3 software which revealed that the patients slept for 67% of the night and napped for 9% of the day. Patients with more disturbed sleep and less robust circadian rhythms performed more poorly on neuropsychological tests. Patients with higher cognitive functioning and fewer extrapyramidal symptoms were more alert during the day. Few patients were exposed to high levels of illumination during the day, and older age was associated with lower levels of light exposure. Duration of antipsychotic use and higher antipsychotic doses were associated with decreased daytime alertness and less robust circadian activity rhythms. Patients taking antipsychotics were more sleepy both during the day and night than patients not taking antipsychotics. The circadian rhythm disturbances found in these patients did not seem to be due solely to low levels of illumination exposure. Life-style factors, behavioral factors, psychiatric symptoms and medications were likely contributors to the disturbed rhythms. The effects of the sleep disturbances did not seem to be benign. There were strong relationships between sleep and circadian rhythms and functioning.

Age Factors↗
PubMed2001

Thermophilic multidrug-resistant Campylobacter fetus infection with hypersplenism and histiocytic phagocytosis in a patient with acquired immunodeficiency syndrome.

We present a case report of a patient who had acquired immunodeficiency syndrome (AIDS) and Campylobacter fetus infection with a number of unusual clinical and microbiological features. The patient had prominent gastrointestinal symptoms, splenic infarction, splenomegaly with hypersplenism, and hemophagocytic histiocytosis in the spleen and lymph nodes; the organism displayed growth on Campy-selective blood agar, thermotolerance, and resistance to quinolones, piperacillin/tazobactam, ceftazidime, and erythromycin.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Deep hypothermic circulatory arrest: I. Effects of cooling on electroencephalogram and evoked potentials.

BACKGROUND: Deep hypothermia is an important cerebral protectant and is critical in procedures requiring circulatory arrest. The purpose of this study was to determine the factors that influence the neurophysiologic changes during cooling before circulatory arrest, in particular the occurrence of electrocerebral silence. METHODS: In 109 patients undergoing hypothermic circulatory arrest with neurophysiologic monitoring, five electrophysiologic events were selected for detailed study. RESULTS: The mean nasopharyngeal temperature when periodic complexes appeared in the electroencephalogram after cooling was 29.6 degrees C +/- 3 degrees C, electroencephalogram burst-suppression appeared at 24.4 degrees C +/- 4 degrees C, and electrocerebral silence appeared at 17.8 degrees C +/- 4 degrees C. The N20-P22 complex of the somatosensory evoked response disappeared at 21.4 degrees C +/- 4 degrees C, and the somatosensory evoked response N13 wave disappeared at 17.3 degrees C +/- 4 degrees C. The temperatures of these various events were not significantly affected by any patient-specific or surgical variables, although the time to cool to electrocerebral silence was prolonged by high hemoglobin concentrations, low arterial partial pressure of carbon dioxide, and by slow cooling rates. Only 60% of patients demonstrated electrocerebral silence by either a nasopharyngeal temperature of 18 degrees C or a cooling time of 30 minutes. CONCLUSIONS: With the high degree of interpatient variability in these neurophysiologic measures, the only absolute predictors of electrocerebral silence were nasopharyngeal temperature below 12.5 degrees C and cooling longer than 50 minutes.

Aged↗
PubMed2001

Deep hypothermic circulatory arrest: II. Changes in electroencephalogram and evoked potentials during rewarming.

BACKGROUND: Electrophysiologic studies during rewarming after deep hypothermic circulatory arrest probe the state of the brain during this critical period and may provide insight into the neurological effects of circulatory arrest and the neurologic outcome. METHODS: Electroencephalogram (EEG) and evoked potentials were monitored during rewarming in 109 patients undergoing aortic surgery with hypothermic circulatory arrest. RESULTS: The sequence of neurophysiologic events during rewarming did not mirror the events during cooling. The evoked potentials recovered first followed by EEG burst-suppression and then continuous EEG. The time to recovery of the evoked potentials N20-P22 complex was significantly correlated with the time of circulatory arrest even in patients without postoperative neurologic deficits (r = 0.37, (p = 0.002). The nasopharyngeal temperatures at which continuous EEG activity and the N20-P22 complex returned were strongly correlated (r = 0.44, p = 0.0002; r = 0.41, p = 0.00003) with postoperative neurologic impairment. Specifically, the relative risk for postoperative neurologic impairment increased by a factor of 1.56 (95% CI 1.1 to 2.2) for every degree increase in temperature at which the EEG first became continuous. CONCLUSIONS: No trend toward shortened recovery times or improved neurologic outcome was noted with lower temperatures at circulatory arrest, indicating that the process of cooling to electrocerebral silence produced a relatively uniform degree of cerebral protection, independent of the actual nasopharyngeal temperature.

Aged↗
PubMed2001

Effects of adenosine receptor subtype A1 on ventricular and renal function.

The adenosine subtype 1 (A1) receptor, which may influence cardiac function and modulate renal function, may have particular relevance in congestive heart failure (CHF). However, the effects of A1 receptor inhibition in the setting of CHF are poorly defined. Systemic hemodynamics and indices of renal function were measured in pigs with pacing-induced CHF at 240 bpm for 3 weeks (n = 10) before and after A1 receptor blockade with 100 microg of BG9719 (1,3-dipropyl-8-[2-(5,6-epoxynorbornyl)]xanthene) or in CHF pigs after infusion of vehicle only (n = 10). Heart rate, mean aortic pressure, and left ventricular peak pressure increased following A1 blockade in the CHF group, consistent with an adenosine inhibitory effect. However, cardiac output and global measures of vascular resistance did not significantly change following A1 blockade. Urine output increased twofold and sodium clearance increased threefold following A1 blockade (p < 0.05). Creatinine clearance increased following A1 blockade (127 +/- 17 vs. 62 +/- 7 ml/min, p < 0.05). Selective A1 receptor blockade improved glomerular filtration rate and induced a natriuresis and diuresis in a model of CHF without adverse effects on cardiac function. These unique results suggest that renal A1 receptor activation may contribute to the reduced renal function associated with CHF.

Animals↗
PubMed2000

Phorbol ester-induced expression of airway squamous cell differentiation marker, SPRR1B, is regulated by protein kinase Cdelta /Ras/MEKK1/MKK1-dependent/AP-1 signal transduction pathway.

The transcriptional induction of SPRR1B by phorbol 12-myristate 13-acetate (PMA) is mainly mediated by the first -152-base pair 5'-flanking region containing two functional AP-1 sites. In this study, we have analyzed the signaling pathways that mediate the induction in tracheobronchial epithelial cells. PKC inhibitor ablated PMA-stimulated expression of endogenous SPRR1B and reporter gene expression driven by SPRR1B promoter. PKC activator promoted the transcription. The dominant negative protein kinase Cdelta (dn-PKCdelta) and rottlerin (PKCdelta inhibitor) completely suppressed PMA-stimulated promoter activity. dn-Ras or dn-MEKK1 inhibited PMA-stimulated promoter activity, while their corresponding constitutively active mutants augmented it. dn-c-Raf-1 did not have any effect on reporter gene expression. Since MEKK1 activates multiple parallel pathways, we examined involvement of JNK/SAPK, p38, and MKK1 in promoter regulation. Co-expression of the dominant negative forms of MKK4, MKK7, JNK/SAPK, MKK3, MKK6, or p38alpha did not suppress PMA-stimulated reporter gene expression. However, MKK1 inhibitors UO126 and PD98095 suppressed gene expression. Consistent with this, expression of dn-MKK1 strongly suppressed PMA-stimulated promoter activity, while the constitutively active MKK1 augmented it. However, MKK1-mediated induction of SPRR1B probably does not depend on extracellular signal-regulated kinases 1 and 2, suggesting the requirement of another kinase(s). dn-c-Jun mutants abolished PMA-stimulated expression supporting an important role for AP-1 proteins in SPRR1B expression. Together, these results suggest that a PKCdelta/Ras/MEKK1/MKK1-dependent/AP-1 pathway regulates the PMA-inducible expression of the SPRR1B in tracheobronchial epithelial cells.

Cell Differentiation↗
PubMed2000

Management of negative symptoms among patients with schizophrenia attending multiple-family groups.

OBJECTIVE: Outcomes for negative symptoms over a one-year period were examined in two groups of patients, one receiving psychoeducational multiple-family group treatment and one receiving standard care. METHODS: A total of 63 outpatients, ages 18 to 45 years, with DSM-IV diagnoses of schizophrenic disorders were randomly assigned to standard care or multiple-family group psychoeducation treatment at a large mental health center in Spokane, Washington. Treatment assignment was stratified by whether patients were taking typical or atypical antipsychotic medications. Negative symptom status was monitored monthly for one year by raters blind to group assignment and measured as a composite of five symptoms using the Modified Scale for the Assessment of Negative Symptoms. RESULTS: When the analysis controlled for baseline negative symptoms, participants in the multiple-family group experienced significantly reduced negative symptoms compared with those receiving standard care. Taking atypical antipsychotic medication or having a diagnosis of substance abuse was not associated with the severity of negative symptoms. An additional analysis of the five individual negative symptoms indicated small but consistent group differences on all dimensions except inattention. Negative symptoms were significantly correlated with relapse to acute illness but not with outpatient or inpatient service use. CONCLUSIONS: The study demonstrated that a psychoeducational multiple-family group intervention was more effective than standard care in managing negative symptoms over a 12-month period. The results are particularly relevant because negative symptoms are associated with relapse, poor social and occupational functioning, cognitive impairment, and lower subjective quality of life.

Adolescent↗
PubMed1999

Sleep-disordered breathing and periodic limb movements in sleep in older patients with schizophrenia.

BACKGROUND: Since the prevalence of both sleep-disordered breathing (SDB) and periodic limb movements in sleep (PLMS) increase with age, we explored whether older schizophrenia patients would have a high incidence of SDB and PLMS. Correlations between sleep and clinical variables were also examined. METHODS: Fifty-two patients (mean age = 59.6 years, SD = 8.9) had their sleep/wake, respiration, and leg movements recorded using a modified Medilog/Respitrace portable recording system plus oximetry. A battery of clinical, psychosocial, and motor disturbance variables were collected by research center staff. RESULTS: Forty-eight percent of these patients had at least 10 respiratory events per hour of sleep. These patients reported more symptoms of daytime sleepiness than patients with fewer than 10 events per hour. The relatively high prevalence of SDB in this group may contribute to overall sleep disturbances, and does not appear to be a result of high body mass index. Only 14% of the patients had at least five limb movements per hour of sleep, suggesting the prevalence of PLMS is much lower than expected in this age group. The number of leg jerks was inversely related to symptoms of tardive dyskinesia. CONCLUSIONS: The disturbance of sleep in these patients may be due, in part, to SDB, but is unlikely due to PLMS.

Age Factors↗
PubMed1999

Effects of dietary taurine supplementation or deprivation in aged male Fischer 344 rats.

Taurine is a sulfur amino acid that is present in high concentration in mammalian tissues and previously has been reported to decline in a number of tissues with advancing age. The aims of the present study were to examine: (1) the effects of dietary taurine supplementation; (2) the effects of taurine-free diets; (3) the ability of aged rats to conserve urinary taurine; and (4) the consequences of these dietary manipulations on some biochemical parameters. Male F344 rats (n = 30/group) 18 months of age were placed on control diets, diets supplemented with 1.5% taurine in the drinking water, or a taurine-free diet for 10 months. An adult control group (12 months old at the end of the study) on normal diets was included for comparison purposes. Significant (P < 0.05) age-related declines in taurine content were observed in the spleen, kidney, eye, cerebellum and serum. Taurine supplementation corrected these deficits in tissue content in aged rats and in many cases increased taurine content above that of adult controls. Urinary excretion of taurine was significantly (P < 0.05) reduced in aged rats indicating an increased need to conserve taurine. Taurine-deficient diets did not further exacerbate the age-related decline in tissue taurine content, suggesting biosynthetic adaptations to the lack of dietary taurine. Dietary taurine supplementation blunted age-related declines in serum IGF-1 and increases in serum creatinine and blood urinary nitrogen (BUN). These studies suggest that advanced aging results in a taurine-deficient state that can be corrected by dietary supplementation.

Aging↗
PubMed1999

Pseudosparing of the endplate: a potential pitfall in using MR imaging to diagnose infectious spondylitis.

OBJECTIVE: The objective of this study was to describe a potential pitfall in using MR imaging to diagnose infectious spondylitis called "pseudosparing" of the endplate, in which the diseased endplate appears to be better defined than a healthy endplate. CONCLUSION: Poor definition of the endplate is a classic radiographic finding in infectious spondylitis; on MR imaging, however, increased conspicuity, or "pseudosparing," was common in our study. Pseudosparing occurs when the normal chemical shift artifact seen in healthy endplates is lost as a result of infiltration of the bone marrow by a pathologic process.

Adult↗
PubMed1999

Physiologic study of pressure point techniques used in the martial arts.

BACKGROUND: Study physiologic changes occurring during "knockouts" produced by application of pressure point techniques during martial arts demonstrations. METHODS EXPERIMENTAL DESIGN: prospective analysis of physiologic variables during and immediately following an acute event. SETTING: martial arts demonstration carried out at a medical center hospital. SUBJECTS: 12 normal volunteers participating in a martial arts demonstration. INTERVENTIONS: application of various pressure point techniques that have been observed to produce states of unresponsiveness in volunteers. MEASURES: continuous ECG and video/EEG monitoring with measurements of blood pressure and oxygen saturation. Qualitative analysis of EEG and ECG recordings and quantitative comparison of heart rate, blood pressure, and oxygen saturation measurements before during and after the period of induced unconsciousness. RESULTS: No significant changes in blood pressure, oxygen saturation, cardiac rate or rhythm, or electroencephalogram are noted during the knockouts produced by application of pressure point techniques. There was only variable inability for subjects to remember words spoken to them during the episode of apparent unresponsiveness. CONCLUSIONS: The mechanism for the state of unresponsiveness produced by application of pressure point techniques is not related to a significant cardiac or pulmonary process. There is no evidence of reduced cerebral blood flow during this time or of other dangerous physiologic changes. The exact mechanism for this phenomenon remains uncertain.

Adult↗