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Biomedical subjects

J Callahan

Publications and source records attributed to J Callahan.

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

Negative effects of a school suicide postvention program--a case example.

In recent years, a general consensus has emerged regarding postvention activities in schools following completed suicides of teenagers. In this case study, standard postvention activities were carried out in a middle school after two youths from the same neighborhood committed suicide 3 months apart. Soon thereafter, a substantial increase in suicidal talk, threats, and attempts took place. Inadvertently, some of the postvention activities appeared to contribute to the romanticization and glorification of the deaths. Changes in postvention practices were made in order to defuse the atmosphere of "romantic tragedy," which in turn led to a decrease in suicidal behavior.

Adolescent↗
PubMed1996

Documentation of client dangerousness in a managed care environment.

The rapid growth of managed care has accelerated the evolution of the clinical record. Previously used for process notations, global assessment, and treatment planning, the record is increasingly used to demonstrate accountability to third-party payers and to the legal system. This article discusses the documentation of accountability in the case of potential client suicide or violence toward others.

Dangerous Behavior↗
PubMed1996

Social work with suicidal clients: challenges of implementing practice guidelines and standards of care.

Practice guidelines and standards of care are detailed models of intervention processes that describe goals, objectives, processes procedures, and interactions. Disciplines other than social work have developed practice guidelines, and it is appropriate for social work to also define standards or guidelines. This article describes an attempt by hospital social work staff to enact social work standards of care for suicidal clients. The difficulties and challenge of developing standards and guidelines are discussed and reasons for the lack of success of the attempt are highlighted.

Humans↗
PubMed1996

Physician-hospital transactions: developing a process for handling valuation-related issues.

Hospitals are increasingly attempting to integrate their operations with physician constituents through the development of hospital-physician joint ventures and acquisition of physician practices. This article provides an overview of valuation-related issues that result with respect to such affiliation efforts and guidance to assist the health care financial and legal professional in resolving such issues consistent with the business objectives of the transaction parties.

Costs and Cost Analysis↗
PubMed1995

Recycling of the 67-kDa elastin binding protein in arterial myocytes is imperative for secretion of tropoelastin.

We have shown previously that the 67-kDa elastin binding protein (EBP) colocalizes intracellularly and extracellularly with tropoelastin in fetal sheep aorta, suggesting that these two proteins associate along the secretory pathway. Moreover, we have established that association with EBP protects tropoelastin from serine proteinases and from intracellular coacervation, and is necessary for its proper extracellular assembly. Since the production of tropoelastin by aortic smooth muscle cells (Ao SMC) exceeds production of the EBP, we speculated that this binding protein might recycle back into the cell, associating again with newly synthesized tropoelastin. In this report we labeled cultured Ao SMC externally with the F(ab')2 fragments of immunoglobulin which recognizes sheep EBP and followed trafficking of EBP by immunofluorescence and electron microscopy. Our results indicate that the majority of the EBP residing on the cell surface can be internalized to endocytic compartments (but not to lysosomes) and recycled back to the plasma membrane within 45-60 min. We have also determined that reagents disturbing pH of distinct endocytic compartments (chloroquine and bafilomycin A1, but not ammonium chloride) arrest recycling of the EBP and, at the same time, strongly inhibit deposition of insoluble elastin in cultures of sheep Ao SMC and in organ cultures of chicken aorta. In contrast, neither chloroquine nor bafilomycin A1 inhibit total protein synthesis or synthesis of tropoelastin. Our results suggest that the EBP serves as a reusable shuttle protein for tropoelastin and that its recycling is essential for effective deposition of insoluble elastin.

Animals↗
PubMed1995

Quantification of thyrotropin-releasing hormone changes and serotonin content changes following graded spinal cord injury.

Thyrotropin-releasing hormone (TRH) and serotonin (5-HT) are well known as neurotransmitters of descending bulbo-spinal tracts. 5-HT uptake caudal to (5-HT decreased) graded spinal lesions has been measured in rats and dogs and significantly correlated with the degree of cord injury. We studied 5-HT content via high-pressure liquid chromatography and radioimmunoassay measurements of TRH in dog spinal cord, both rostral and caudal, to 6 week T6 spinal transection (T) (n = 7) or T6 hemisections (H) (n = 7). Sham controls (n = 7) were used. Mean 5-HT content values were (pmole/mg): rostral sham 1.25 +/- 0.02, caudal sham 1.35 +/- 0.17, rostral T 2.65 +/- 0.36, caudal T 0.19 +/- 0.06, rostral H 2.1 +/- 0.22, and caudal H 1.0 +/- 0.31. A significant decrease in 5-HT caudal to transection versus control (P < 0.001) was seen. A trend for decreased 5-HT caudal to hemisection versus control (P < 0.1) was also seen. Mean TRH levels (pg/mg protein) were: rostral sham 40.02 +/- 18.47, caudal sham 30.61 +/- 10.03, brainstem sham 18.9 +/- 5.13, rostral T 52.4 +/- 21.34, caudal T 3.52 +/- 1.87, brainstem T 19.25 +/- 4.11, rostral H 43.45 +/- 18.61, caudal H 14.24 +/- 5.7, and brainstem H 21.89 +/- 1.23. Significant decreases for caudal TRH transection versus controls (P < 0.001) and for caudal TRH hemisection versus controls (P < 0.02) were seen. A significant difference between caudal hemisection and caudal transection TRH levels (P < 0.001) was seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The ethics of assisted suicide.

The ethics of assisted suicide and the wisdom of changing public policy to support assisted suicide are considered from the perspective of the social work profession. The traditional social work value of client self-determination is reviewed and discussed, and tensions in this ideal and conflicts with another primary social work value--client well-being--are identified. The primacy of the client's well-being sometimes, in the professional judgment of the social worker, overrides a client's stated wish. This article finds assisted suicide unethical: Studies indicate that the judgment of most suicidal people is impaired as a result of depression or other mental illness. Truly "rational suicide" may exist but is probably quite rare compared to the overwhelming majority of suicides. In addition, assisted suicide may lead to increased rates of suicide in the general population, especially among young people, because of the contagion phenomenon and the destigmatization of suicide.

Beneficence↗
PubMed1994

Defining crisis and emergency.

All too often, a crisis is responded to inappropriately, as if it were an emergency. Similarly, an emergency is often inappropriately treated with crisis intervention. Resources are wasted or the client receives unsuitable care. It becomes clear when reading the literature that no consensus has been achieved regarding definitions of the terms "crisis" and "emergency." This article argues that the terms are not interchangeable, offers specific definitions of each, and discusses some of the implications of the definitions. The confusing situations which arise in clinical practice may be clarified by the use of these definitions, and it is hoped that they will lead to more appropriate clinical decision making.

Crisis Intervention↗
PubMed1993

The 67-kD elastin/laminin-binding protein is related to an enzymatically inactive, alternatively spliced form of beta-galactosidase.

We and others have previously shown that a 67-kD cell surface elastin/laminin-binding protein (EBP) is responsible for cell adhesion to elastin and laminin and for mediating the process of elastin fiber assembly, but the nature of this protein was unknown. In this report we provide evidence that a 67-kD catalytically inactive form of beta-galactosidase produced by alternative splicing demonstrates immunological and functional similarity and sequence homology to the 67-kD EBP, suggesting that the two might be the same. Antibody prepared to a synthetic peptide, N-Ac-GSPSAQDEASPL, corresponding to a frame-shift-generated sequence unique to the alternatively spliced form of human beta-galactosidase, also recognized sheep EBP both on Western blotting and in aortic tissue. Furthermore, this synthetic peptide (S-GAL) binds to elastin and laminin, but not to fibronectin, collagen I, or collagen III. Moreover, both tropoelastin and laminin which bind to S-GAL peptide affinity columns can be specifically eluted from them with an excess of free S-GAL peptides. In addition, sequence homology among this splice variant of human beta-galactosidase, sheep EBP, and NH2-terminal sequences of some elastases suggests that these proteins share a common ligand-binding motif that has not been previously recognized.

Alternative Splicing↗
PubMed1993

T cell tolerance. Giles F. Filley Lecture.

T cell tolerance to self is induced by several mechanisms. Immature T cells may die, and mature T cells may die or be inactivated by contact with self. While we do not understand completely what governs which of these courses will be adopted by an autoreactive T cell, 2 points are clear. Self is in part distinguished from nonself by the fact that the former is always present, while the latter is only intermittently in the body. Secondly, it seems that the default response for T cells is "off" rather than "on." That is, peripheral T cells will become tolerant to antigen unless some other phenomenon such as adjuvant triggers them to respond. One other point should be mentioned. In spite of the power of the mechanisms which causes self tolerance, tolerance is not complete. Autoreactive T cells specific for cryptic antigens, expressed in the brain or eye for example, can easily be demonstrated. Many autoimmune diseases may be caused by aberrant activation and exposure to target organ of these cells, rather than failure of the normal mechanisms of tolerance themselves.

Animals↗
PubMed1992

The epidemiology of hepatitis C virus antibody in Yemen.

A cross-sectional survey of 348 subjects without evidence of liver disease was conducted to investigate the prevalence and risk factors for hepatitis C virus antibody (anti-HCV) seropositivity in the Yemen Arab Republic. The mean age of study subjects was 28.7 years (range 3-80), and 61% were males. Using commercial enzyme-linked immunosorbent assays (ELISA), 6.0% (95% confidence interval [CI] 3.8-9.1) of subjects were anti-HCV-positive, 13.5% were hepatitis B surface antigen-positive (HBsAg-positive), and 51.4% were positive for at least one serologic marker of prior hepatitis B infection. Nine (2.6%; 95% CI 1.2-4.9) of the 21 ELISA-positive sera were confirmed to be anti-HCV positive by a recombinant immunoblot assay. Anti-HCV seropositivity was significantly associated with age (odds ratio [OR] 2.0 for each 10-year increase in age) and prior surgery (OR 10.1), but was not associated with a history of prior blood transfusion or markers of hepatitis B infection. These preliminary data suggest that hepatitis C may pose a substantial health threat in Yemen.

Adolescent↗
PubMed1991

Immunologic effects of plasmapheresis synchronized with pulse cyclophosphamide in systemic lupus erythematosus.

Extensive immunologic evaluation was made of a patient with severe systemic lupus erythematosus (SLE) undergoing 6 cycles of plasmapheresis combined with pulsed cyclophosphamide therapy. Clinical remission ensued accompanied by normalization of levels of circulating autoantibodies, immune complexes, complement proteins, interleukin 2 (IL-2) and IL-2 receptor. High spontaneous peripheral blood lymphocyte proliferation fluctuated widely with plasmapheresis, but was consistently reduced after cyclophosphamide. Circulating B cells fell by 85% and remained low at one year, despite recovery of the serum IgG level. Circulating T cells declined by 48%, chiefly in the immunologically naive CD4+CD45R+ T cell subset. This was associated with the emergence of a CD8+DR+CDw29+ T cell subset signifying immunologically mature, activated cytotoxic/suppressive T cells, which might have served to control the autoreactive B and T cell populations. Pulsed cyclophosphamide synchronized with plasmapheresis profoundly affected the immune system of our patient. The association of these immunological changes with clinical recovery warrants further investigation of this new therapeutic approach in SLE.

Adult↗
PubMed1991

Percutaneous lumbar discectomy: a new adjunct to open surgery.

Percutaneous automated lumbar discectomy is a new and alternative method to open operations for lumbar disc disease. The procedure and indications for the procedure are explained in this article. The results of the first 24 such procedures performed at the Indiana University Medical Center will be examined and discussed.

Humans↗
PubMed1989

The amino-terminal sequences in the pro-alpha and -beta polypeptides of human lysosomal beta-hexosaminidase A and B are retained in the mature isozymes.

The alpha- and beta-subunits of beta-hexosaminidase (beta-N-acetylhexosaminidase, EC 3.2.1.52) are synthesized in the rough endoplasmic reticulum as prepropolypeptides. After the loss of the signal peptide and formation of enzymatically active dimers, the pro-isoenzymes are transported through the Golgi and into the lysosome for proteolytic and glycolytic processing to their stable mature forms. Maturation includes the hydrolysis, and previously presumed loss, of small N-terminal peptides from each propolypeptide. A recent report characterizing the processing of the beta-prepropolypeptide in beta-hexosaminidase from a human fibroblast cell line [(1989) J. Biol. Chem. 264, 3380-3384] reported that the small pro-beta peptide was retained through a disulfide bond in the mature subunit, and that it was glycosylated. We have confirmed this result in normal human tissue. However, we report a different N-terminal for the mature pro-beta peptide. Furthermore, we have found that the pro-alpha peptide is similarly retained in the mature alpha-subunit through its single cysteine residue and that each pro-peptide undergoes C-terminal processing.

Amino Acid Sequence↗