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Biomedical subjects

B Nelson

Publications and source records attributed to B Nelson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Nocturnal ACTH, cortisol, growth hormone, and prolactin secretion in prepubertal depression.

OBJECTIVE: To examine nocturnal secretion of adrenocorticotropin, cortisol, growth hormone, and prolactin in 38 medically healthy children with prepubertal major depression compared with 28 medically and psychiatrically healthy control children. METHOD: Prior to sampling, subjects underwent an "adaptation night" with the intravenous catheter in place and electroencephalographic (EEG) electrodes for standard all-night polysomnogram. On the following night, plasma samples were obtained every 20 minutes through an indwelling catheter. Hormonal concentrations were measured by specific radioimmunoassay and aligned by EEG-confirmed sleep onset. Areas under the curve were calculated for total secretion and compared using analysis of variance. RESULTS: Prepubertal depressed children had lower cortisol secretion during the first 4 hours after sleep onset compared with controls. Adrenocorticotropin, prolactin, and growth hormone secretion did not differ between groups. Examination of clinical characteristics in depressed children revealed lower nocturnal adrenocorticotropin concentrations in depressed inpatients versus depressed outpatients and in depressed sexually abused versus depressed nonabused children. A significant sex by diagnosis effect revealed lower growth hormone secretion in depressed females compared with depressed males. CONCLUSIONS: In contrast to neuroendocrine challenge studies in these same subjects, nocturnal neuroendocrine measures did not reveal any of the expected group differences. These results emphasize the contrasts between unstimulated and challenge studies of neuroendocrine secretion and of the importance of considering clinical characteristics and maturation influences in biological studies of prepubertal depression.

Adolescent↗
PubMed1996

Childhood and adolescent depression: a review of the past 10 years. Part I.

OBJECTIVE: To qualitatively review the literature of the past decade covering the epidemiology, clinical characteristics, natural course, biology, and other correlates of early-onset major depressive disorder (MDD) and dysthymic disorder (DD). METHOD: A computerized search for articles published during the past 10 years was made and selected studies are presented. RESULTS: Early-onset MDD and DD are frequent, recurrent, and familial disorders that tend to continue into adulthood, and they are frequently accompanied by other psychiatric disorders. These disorders are usually associated with poor psychosocial and academic outcome and increased risk for substance abuse, bipolar disorder, and suicide. In addition, DD increases the risk for MDD. There is a secular increase in the prevalence of MDD, and it appears that MDD is occurring at an earlier age in successive cohorts. Several genetic, familial, demographic, psychosocial, cognitive, and biological correlates of onset and course of early-onset depression have been identified. Few studies, however, have examined the combined effects of these correlates. CONCLUSIONS: Considerable advances have been made in our knowledge of early-onset depression. Nevertheless, further research is needed in understanding the pathogenesis of childhood mood disorders. Toward this end, studies aimed at elucidating mechanisms and interrelationships among the different domains of risk factors are needed.

Adolescent↗
PubMed1996

Management of back pain in athletes.

Back pain affects millions of people. It affects 80% of the population and up to 52% at any given time. Back pain is not limited to sedentary individuals; it has significant effects on athletes as well. Depending upon the sport, incidence rates of back pain occur in athletes from 1.1% to as high as 30%. Athletes differ from the non-athletic population in that their incentives to return to activity are considerably different than non-athletes. The reasons may vary from the will to win through to significant financial considerations. Although reasons for recovery are different, the physiology and mechanics of repair of injured soft tissue in the athlete is the same as for the non-athlete. Proper management of the athlete requires ruling out emergent causes of back pain such as tumour, infection, acute fracture, progressive neurological deficit, visceral sources (e.g. pancreatitis, abdominal aortic aneurysm), and rheumatoid variants. Once a good history and physical is performed, a simple classification system can be utilised to manage the athlete presenting with back pain. This system can be expressed as: (a) regional back pain; (b) radicular leg pain; (c) radicular leg pain with progressive neurological deficit; and (d) cauda equina syndrome. Each of these categories needs to be managed in a specific manner and can provide the healthcare professional with simple, straightforward guidelines for handling the athlete with lower back pain. The key is to return the athlete to the field of play in a safe and timely manner.

Athletic Injuries↗
PubMed1995

Stressful life events and EEG sleep in depressed and normal control adolescents.

EEG sleep measures in 35 depressed and 33 normal control adolescents were examined in relation to stressful life events occurring in the year before sleep studies. There was a significant interaction between stressful life events and diagnostic status for REM latency and total REM time. In the normal controls, the presence of stressful life events was significantly associated with reduced REM latency and increased total REM time. Among the depressed adolescents, there were no significant effects of stressful life events on REM latency or total REM time. The depressed adolescents with no stressful life events (n = 9) had significantly lower REM latency values compared to normal control adolescents with no stressful life events (n = 13)(61.7 +/- 50.0 vs. 132.1 +/- 79.0, p < or = .01). It appears that stressful life events influence at least some measures of adolescent sleep and should be considered in future controlled studies aimed at understanding sleep changes in adolescent depression.

Adolescent↗
PubMed1995

Unipolar depression in adolescents: clinical outcome in adulthood.

OBJECTIVE: This study examined the longitudinal clinical course and adult sequelae of adolescent unipolar major depressive disorder (MDD) using a controlled longitudinal design. METHOD: Subjects were 28 adolescents (15.4 +/- 1.3 years) with systematically diagnosed unipolar MDD and 35 group-matched control subjects who participated in a cross-sectional electroencephalogram sleep and neuroendocrine study. Using standardized instruments, interviewers who were blind to subjects' initial diagnoses conducted follow-up clinical assessments 7.0 +/- 0.5 years later in 94% of the original cohort. RESULTS: The depressed group showed high rates of recurrence of MDD episodes during the interval period (69%). They also had elevated rates of new-onset bipolar disorder (19%). Twenty-three percent of subjects with an initial diagnosis of MDD had no additional depressive episodes after the index assessment. The rate of new onset of depression in the controls was 21%. Low socioeconomic status predicted recurrence of depressive episodes in the MDD group. MDD subjects with recurrence(s) and controls with new onset of depression during the follow-up period had significant psychosocial morbidity, as evidenced by disruption in interpersonal relationships and dissatisfaction with life and decrease in global functioning, compared with both MDD subjects with no further episodes and control subjects who had never been psychiatrically ill. These psychosocial deficits persisted remission from depressive episode(s). CONCLUSIONS: Adolescent unipolar MDD predicts continued risk for recurrences with persistence of depressive episodes and psychosocial morbidity into adulthood. A sizable minority, however, have sustained periods of remission associated with good social adjustment.

Adolescent↗
PubMed1995

Dealing with inappropriate behavior on a multidisciplinary level: A policy is formed.

Rapid changes due to healthcare reform have impacted the patient care setting, demanding that care is provided in an efficient manner--a team working in harmony to meet patient care needs. However, inappropriate behavior at the work site continues to rob healthcare providers of valuable time as they stop to regroup from its effects on staff and organizations. A search in the Dixie Regional Medical Center in St. George, Utah, to solve this age-old dilemma led to the formation of a policy to guide staff members in a positive direction when resolving conflict issues. This article addresses these efforts.

Conflict, Psychological↗
PubMed1995

Probing collinearity bias in the close induction field.

The substrates of the Poggendorff illusion can be evaluated using as few as two line segments, a test segment whose collinearity is judged, and an induction segment which serves to bias that judgment. Previous research from this laboratory has shown that a very short induction segment can produce a substantial bias of perceived collinearity when it is centered at the tip of the test segment, and there is some evidence that the symmetry of this configuration affects the strength of this bias. Four experiments were conducted to clarify the issue of symmetry in the stimulation of the "half-field" zones which lie on each side of the tip. That Exp. 1a showed displacements which moved the induction segment to an eccentric position, i.e., occupying a single half-field, reduced collinearity error. With additional displacement which produced a gap there was a rebound of induction effect. Exp. 1b indicated that an eccentric induction segment does not produce the usual strength or pattern of bias as a function of its orientation relative to the test segment. Exp. 2a suggested that the strength of induction effect is a function of symmetry within the half-fields rather than the lengths of the segments per se. Finally, in Exp. 2b the strength of induction was a joint function of the position of a short segment within one half-field and the length of another segment which stimulated the other half-field. The effect showed a complex oscillation with changes in position. We discuss the induction mechanism as beginning with "contour filters" which register the induction segment(s) and which combine their responses on the basis of "tandem activation" of the close half-fields.

Form Perception↗
PubMed1995

Discordant expression of Bcl-x and Bcl-2 by keratinocytes in vitro and psoriatic keratinocytes in vivo.

Apoptosis is a required event in maintaining kinetic homeostasis within continually renewing tissues such as skin. However, no systematic study of the apoptotic process in epidermal keratinocytes of the skin has been performed. In this report, we examined the expression of proteins associated with promoting (Fas) or preventing (Bcl-2, Bcl-x, CD40) apoptosis in the normal, psoriatic, and malignant keratinocyte. Immunohistochemical staining and flow cytometry analysis revealed that normal cultured keratinocytes express low levels of Fas, CD40, and Bcl-x that was enhanced by cytokines including gamma-interferon (IFN-gamma) and a phorbol ester tumor promoter, TPA. Only faint Bcl-2 staining was detected in cultured keratinocytes exposed to IFN-gamma and TPA compared with the prominent expression of Bcl-x. Biopsies of normal skin, psoriatic plaques, and basal cell carcinomas were examined to extend the in vitro observations. Immunohistochemical staining revealed that while keratinocytes in normal epithelium express low to absent levels of Fas and Bcl-x, psoriatic keratinocytes expressed significantly higher levels of Fas and Bcl-x. In contrast, malignant keratinocytes in basal cell carcinomas expressed high levels of Bcl-2, but minimal Bcl-x, and no Fas. Immunoblot analysis revealed that the long form of Bcl-x (Bcl-xI), which prevents apoptosis in lymphocytes, is expressed by cultured keratinocytes and psoriatic plaque keratinocytes. We conclude that normal cytokine-activated keratinocytes can express an apoptotic (Fas) and an anti-apoptotic protein (Bcl-x). The overexpression of Bcl-x in psoriasis, or Bcl-2 in basal cell carcinomas, may contribute to the longevity of these cells by blocking the normal apoptotic process involved in the terminal differentiation program of epidermal keratinocytes.

Adult↗
PubMed1995

Caring and the health professions.

This study analyzes patient descriptions of what constitutes caring in the physician and nurse. We propose that health care students can be taught caring behavior through the use of patient narratives.

Humans↗
PubMed1995

Recombinant endotoxin-binding protein (rBPI23) attenuates endotoxin-induced circulatory changes in humans.

In the present study the protective effect of a recombinant endotoxin-binding protein rBPI23 on the circulatory changes in experimental endotoxemia in humans was investigated. In a controlled, blinded crossover study, eight volunteers were challenged twice with an intravenous bolus injection of endotoxin (40 EU/kg body weight), and concurrently received either rBPI23 (1 mg/kg) or placebo (human serum albumin, 0.2 mg/kg). Hemodynamic parameters were obtained non-invasively by means of M-mode, two-dimensional, and Doppler echocardiography. rBPI23 significantly reduced indices of the endotoxin-induced hyperdynamic circulation. rBPI23 treatment significantly reduced increase in cardiac index (P = 0.0156). rBPI23 treatment diminished the endotoxin-induced decrease in systemic vascular resistance index (P = 0.0304). rBPI23 did not prevent the endotoxin-induced rise in body temperature and systolic, diastolic and mean arterial pressure were not significantly different in the rBPI23- and placebo-treatment arm. Both treatment periods showed a small reduction in end diastolic and end systolic volumes. rBPI23 treatment slightly reduced the increase in M-mode ejection fraction and fractional shortening. These results indicate that rBPI23 is capable of attenuating the potentially deleterious circulatory effects of endotoxin in humans.

Adult↗
PubMed1994

Casemix--an AMA perspective.

The introduction of casemix payment systems into Australia's public hospitals is an inevitability which the Australian Medical Association has now begun to address. A greater involvement of clinicians in the design and implementation of casemix can add substantial quality to these systems. However, there is concern that a proliferation of separate casemix systems may be contrary to overall health policy developments and that governments will not understand the limits of casemix. Recent attempts to include medical payments within a casemix payment system in the private sector faced our united opposition. Finally, special care needs to be taken to ensure that the introduction of a casemix payment system does not further disadvantage access to high quality health care for Aborigines.

Australia↗
PubMed1994

The 24-hour pattern of prolactin secretion in depressed and normal adolescents.

Plasma prolactin concentrations were measured at 20-min intervals over a 24-hr period in 49 adolescents with major depressive disorder (MDD) and 39 normal control adolescents. Neither the pattern nor the amount of prolactin secretion was significantly different between these two groups. There were significant gender differences, with girls secreting more prolactin than boys, but no significant gender-by-diagnosis interactions were found. With the possible exception of psychosis, dividing the MDD sample based on clinical characteristics failed to reveal differences. These findings are discussed in the context of changes in prolactin in childhood depression using a serotonergic challenge study, as well as in relation to baseline prolactin studies in adult depression.

Adolescent↗
PubMed1994

Genetic modification of T cell clones to improve the safety and efficacy of adoptive T cell therapy.

Our laboratory has developed methods to isolate human antigen-specific cytolytic CD8+ T cell clones and to expand such clones in vitro to numbers sufficient for T cell therapy of human diseases. Studies in immunocompromised bone marrow transplant patients at high risk for disease associated with cytomegalovirus have demonstrated that administration of more than 10(9) CD8+ T cell clones is safe and can effectively reconstitute a deficient human immune response. Our laboratory is applying this strategy of adoptive therapy to the treatment of human cancer, starting with the subset of patients with Hodgkin's disease who show expression of proteins encoded by the Epstein-Barr virus in their malignant Reed-Sternberg cells. The development of efficient systems such as retroviral vectors for the introduction of genes into primary cells has made it possible to consider overcoming some of the limitations of the effector T cells that normally mediate response to an antigen. Our laboratory is attempting to modify T cell clones by the introduction of genes before transfer as a means to improve the safety and/or efficacy of T cell therapy.

Antigens, Viral↗
PubMed1994

Cholinergic REM induction test with arecoline in depressed children.

Children with major depressive disorder often fail to exhibit electroencephalographic (EEG) sleep abnormalities similar to those reported in depressed adults. It was hypothesized that a cholinergic rapid eye movement (REM) induction test would contribute to the identification of EEG sleep abnormalities in depressed children. To test this hypothesis, prepubertal children meeting research diagnostic criteria for major depressive disorder (n = 33) and carefully screened healthy control children (n = 15) were enrolled in a 4-day psychobiologic protocol that included 1 night with infusion of arecoline (0.5 mg) during the first non-REM sleep period. Although there had been no significant group differences in baseline sleep measures, results on the arecoline night revealed significantly shorter REM latency in the group of depressed children compared with the control children (mean +/- SD = 105 +/- 51 minutes vs. 140 +/- 46 minutes). The design of the protocol (with an interval break immediately preceding the arecoline night) prevented a direct estimation of arecoline effects within subjects; however, these data provide promising preliminary results regarding cholinergic REM induction tests in childhood depression.

Aging↗
PubMed1994

A human Alu RNA-binding protein whose expression is associated with accumulation of small cytoplasmic Alu RNA.

Human Alu sequences are short interspersed DNA elements which have been greatly amplified by retrotransposition. Although initially derived from the 7SL RNA component of signal recognition particle (SRP), the Alu sequence has evolved into a dominant transposon while retaining a specific secondary structure found in 7SL RNA. We previously characterized a set of Alu sequences which are expressed as small cytoplasmic RNAs and isolated a protein that binds to these transcripts. Here we report that biochemical purification of this protein revealed it as the human homolog of the SRP 14 polypeptide which binds the Alu-homologous region of 7SL RNA. The human cDNA predicts an alanine-rich C-terminal tail translated from a trinucleotide repeat not found in the rodent homolog, which accounts for why the human protein-RNA complex migrates more slowly than its rodent counterpart in RNA mobility shift assays. The human Alu RNA-binding protein (RBP) is expressed after transfection of this cDNA into mouse cells. Expression of human RBP in rodent x human somatic cell hybrids is associated with substantial increase in endogenous small cytoplasmic Alu and scB1 transcripts but not other small RNAs. These studies provide evidence that this RBP associates with Alu transcripts in vivo and affects their metabolism and suggests a role for Alu transcripts in translation in an SRP-like manner. Analysis of hybrid lines indicated that the Alu RBP gene maps to human chromosome 15q22, which was confirmed by Southern blotting. The possibility that the primate-specific structure of this protein may have contributed to Alu evolution is considered.

Amino Acid Sequence↗
PubMed1994

Improving cash flow through benchmarking.

Healthcare organizations can use two benchmarking techniques to improve their accounts receivable departments' performance: 1) studying the accounts receivable statistics of model healthcare organizations, and 2) visiting these model organizations in order to get a first-hand look at how they do business. Employing these two benchmarking techniques can help healthcare organizations reduce gross days revenue outstanding, bad debt, the length of time between the date a patient is discharged and the date a bill is mailed, the total percentage of receivables more than 90 days old, and general business office expenses related to collection.

Accounts Payable and Receivable↗