PubMed Health⌕ Search

Biomedical subjects

J Balint

Publications and source records attributed to J Balint.

At least 19 recordsLinked to original sources
PubMed2001

Ethical challenges in the care of infants with intestinal failure and lifelong total parenteral nutrition.

Families, pediatric surgeons, and other care givers face difficult ethical challenges as they balance the benefits and burdens of total parenteral nutrition (TPN) and bowel transplantation in the face of uncertainty and the inability to predict which infants with intestinal failure are likely to have good outcomes. This article presents an analysis of 3 TPN cases using a comparison with dialysis and kidney transplantation, an older and more established technology for which ethical guidelines are proposed in the literature. The authors conclude that pediatric surgeons should recommend TPN in cases in which it is expected to be a temporary measure until bowel function is restored. TPN should not be recommended when other comorbidities make survival unlikely or when the infant is neurologically devastated. In the case of lifelong TPN in which bowel transplantation is only an option when TPN fails, pediatric surgeons should defer to parents in their choice about the use of lifelong TPN.

Ethical Analysis↗
PubMed1999

The basis of informed consent for BMT patients.

During recent decades the doctrine of informed consent has become a standard part of medical care as an expression of patients' rights to self-determination. In situations when only one treatment alternative exists for a potential cure, the extent of a patient's self-determination is constrained. Our hypothesis is that for patients considering a life-saving procedure such as bone marrow transplant (BMT), informed consent has little meaning as a basis for their right to self-determination. A longitudinal study of BMT patients was undertaken with four self-administered questionnaires. Questions centered around expectations, knowledge, anxiety and factors contributing to their decision to undergo treatment. Although the informed consent process made patients more knowledgeable about the treatment, their decision to consent was largely based on positive outcome expectations and on trust in the physician. Informed consent relieved their anxieties and increased their hopes for survival. Our conclusion was that the greatest value of the informed consent process lay in meeting the patients' emotional rather than cognitive needs. When their survival is at stake and BMT represents their only option, the patient's vulnerability puts a moral responsibility on the physician to respect the principle of beneficence while not sacrificing the patient's right to self-determination.

Adult↗
PubMed1998

Blood flow in rat gastrocnemius muscle and Achilles tendon after Achilles tenotomy.

The effect of Achilles tenotomy on resting blood flow of rat gastrocnemius muscle and Achilles tendon was studied by radioactive microspheres. Tenotomy produced an immediate, marked decrease in both intramuscular and intratendinous blood flow and it remained significantly lowered at both sites till the end of the observation period, i.e., day 18 after tenotomy. The decrease in the resting blood flow was more rapid and pronounced in the Achilles tendon than in the gastrocnemius muscle. Although the blood flow of the Achilles tendon started to recover after the 4th postoperative day, it was still 33% (statistically not significant) lower than that in the controls 18 days after tenotomy. In the gastrocnemius muscle, the 18-day deficit was 38% (p < 0.001), respectively. The results indicate that after division of a rat Achilles tendon the resting blood flow to the gastrocnemius muscle and Achilles tendon is not adequately restored, remaining at a significantly lowered level even 18 days after tenotomy.

Achilles Tendon↗
PubMed1996

Regaining the initiative. Forging a new model of the patient-physician relationship.

The patient-physician relationship has undergone major and increasingly rapid changes in the past 40 years. It has moved from a relationship based on physician paternalism, through one of patient autonomy, to one where the patient and the physician's authority and control over the patient's care are facing significant threats from outside sources. In this article, we examine the historical and social forces that have contributed to these changes and the effects these forces have had on the traditional models of the patient-physician relationship. We present arguments to support our proposal for a patient-physician alliance in the community based on mutual education of physician and patient about health and illness, values and persons, social responsibility, beneficence, trust, and a degree of paternalism. We believe such an alliance offers the best hope for patients and their physicians to regain the initiative in guiding the evolution of health care in a way that preserves the essentials of the therapeutic relationship.

Beneficence↗
PubMed1996

Number and morphology of mechanoreceptors in the myotendinous junction of paralysed human muscle.

The mechanoreceptor system of the myotendinous junction (MTJ) of human palmaris longus muscle obtained at autopsy was studied histologically from six patients with flaccid paralysis (complete acute tetraplegia 4-6 weeks before the autopsy, due to a spinal cord injury), eight patients with spastic paralysis (chronic hemiplegia due to cerebral stroke) and ten neurologically normal controls. Four types of nerve endings, Ruffini and Pacini corpuscles, Golgi tendon organs, and free nerve endings, could be identified in the MTJs of the controls. In the MTJs of the patients with flaccid and spastic paralysis, the free nerve endings were not present and the mechanoreceptors that were found were few in number, degenerated, fibrotic, and atrophic. These mechanoreceptors had lost their connection with the muscle fibres and tendon bundles and were frequently located within pathological accumulations of fatty tissue in the myotendinous region. The number and distribution of mechanoreceptors in the MTJ were almost identical in patients with flaccid and spastic paralysis.

Adult↗
PubMed1995

Beard calcium concentration as a marker for coronary heart disease as affected by supplementation with micronutrients including selenium.

Hair calcium concentration is biologically regulated and inversely correlated to the concentration in the aorta. Populations generally divide into high and low hair calcium groups which differ significantly from each other. It has been found that about 90% of people who suffer an acute myocardial infarction belong to the low hair calcium group. It follows that raising a person's calcium status from the low to the high group should decrease their risk of coronary heart disease. A trial was set up with four groups of 12 people, randomly allocated to one of the following treatments: placebo; vitamin D; antioxidants; and antioxidants plus vitamin D. Beard samples were collected for two months prior to four months of supplementation and for two months afterwards. Blood samples were collected at the end of the supplementation period. All treatments significantly lowered plasma calcium concentrations but did not significantly affect beard calcium concentrations due, primarily, to some large individual fluctuations. Within the limitations of the experiment the combined treatment was the most effective as it was the only one to raise beard calcium levels for the duration of the supplementation period. A higher rate of vitamin D supplementation [i.e., > 50% recommended daily allowance (RDA)] might have established clear differences but larger group sizes would also have been helpful. Of the unsupplemented subjects 80% had plasma selenium concentrations of < 90 micrograms l-1 in contrast to only 10% of supplemented ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The role of career pathway before medical school in graduates' choice of primary care versus other specialty practices.

PURPOSE: To analyze the difference, if any, in the choices of primary care versus other specialty practices among graduates of the Albany Medical College who took one of three career pathways before entering medical school and who had entered primary care residencies. METHOD: Questionnaires were mailed in April 1992 to all 458 graduates from the classes of 1980 through 1985 who had entered primary care residencies (i.e., residencies in family practice, general internal medicine, general pediatrics, or medicine--pediatrics). The graduates had followed one of three pathways to admission: (1) after completion of four years of college, (2) after completion of the six-year biomedical program in conjunction with the Rensselaer Polytechnic Institute (RPI), and (3) after having pursued a nonmedical career and being older than 25 years of age. Logistics regression was the primary vehicle for analysis, defining career choice as the dependent variable and using the independent variables of sex, year of graduation, and pathway as well as their interactions for a saturated-model analysis. RESULTS: A total of 318 graduates (69%) responded. Among the three pathways, there was no statistically significant difference in the choices of primary care versus other specialty practices. However, in the RPI and age-greater-than-25 groups, there was a greater tendency for men to choose other specialties. CONCLUSIONS: The three career pathways before medical school did not appear to have a role in the choice of primary care versus other specialty practices among graduates who had entered primary care residencies. However, gender did influence this choice.

Adult↗
PubMed1993

Mechanoreceptors in human myotendinous junction.

The sensory-nerve-ending system of 40 myotendinous junctions of human palmaris longus and plantaris muscles was studied histologically. All the known four types of nerve endings were identified. The Ruffini corpuscles could be found in equally small numbers (one to five) in both the muscular and tendineal sites of the junction. Also the free nerve endings were distributed equally on both sites. The Pacini corpuscles were frequent in the tendineal site (six to 14), but rare in the muscular site (one to three). The Golgi tendon organs were, in turn, frequent in the muscular site (nine to 12) but rare in the tendineal site (one to four), respectively. Within the muscle and tendon parts of the junction, the distance between two mechanoreceptors was always more than 250 microns and the receptor distribution was homogeneous. Further studies are needed to give functional explanation for these anatomic findings.

Adult↗
PubMed1989

Detection, isolation and characterization of staphylococcal enterotoxin B in protein A preparations purified by immunoglobulin G affinity chromatography.

Studies were performed to detect and isolate trace contaminants of staphylococcal enterotoxin B (SEB) in various protein A preparations isolated by affinity chromatography employing human IgG covalently bound to Sepharose 4B. Utilizing an ELISA technique, trace amounts (0.018-0.138%) of SEB could be detected in protein A preparations after separation of the SEB employing a molecular sizing column in a high pressure liquid chromatography (HPLC) system. Trace contamination by SEB could be removed from protein A preparations by an additional DEAE ion exchange chromatography step employing a low ionic strength buffer system (0.005 M NaCl in 0.01 phosphate buffer, pH 7.50). The resulting protein A preparations possessed a purity higher than that observed prior to the final purification step. Polyacrylamide gel electrophoresis (PAGE) analyses of the trace contamination removed from protein A preparations by ion exchange chromatography revealed, in addition to SEB, several additional contaminating polypeptides of an unknown nature. These studies indicate that protein A preparations of high purity can be prepared by employing DEAE ion exchange chromatography in addition to affinity chromatography utilizing immobilized human IgG.

Chromatography, Affinity↗
PubMed1988

Preliminary studies on the detection, isolation and partial characterization of Clq-containing IgM immune complexes in sera of patients with primary biliary cirrhosis.

The complement system is activated in primary biliary cirrhosis (PBC) and this activated state may be medicated by immunoreactive IgM. To identify and further characterize the relationship between the complement (Clq) and IgM in PBC sera, we developed an anti-Clq ELISA method which allowed detection of Clq-containing circulating immune-like complexes. Utilizing this technique, sera from 3 out of 5 patients with PBC revealed circulating immune-like complexes. Moreover, when serum samples were specifically examined for the presence of IgM containing Clq complexes, four of four samples examined were positive. Additional experiments indicated that these immune-like complexes could be removed from PBC sera by means of an anti-Clq immunoadsorbent. Upon subsequent isolation and characterization, these immune-like complexes demonstrated polypeptide chains corresponding to both human Clq and human IgM. Our experimental studies establish that Clq-containing IgM-like complexes can occur in the serum of patients with PBC, and provide additional support for the proposal that immunoreactive IgM can contribute to the activated complement system observed in PBC.

Antigen-Antibody Complex↗
PubMed1984

Tumoricidal response following perfusion over immobilized protein A: identification of immunoglobulin oligomers in serum after perfusion and their partial characterization.

Previously, we showed that perfusion of plasma from hosts bearing breast adenocarcinoma over immobilized staphylococcal protein A resulted in objective tumor regressions. In the present study, sera perfused in vitro over immobilized staphylococcal protein A were analyzed by physicochemical and immunochemical methods to characterize newly formed products. Sera from normal and breast adenocarcinoma-bearing dogs showed increased levels of C1q-binding IgG after perfusion over a strain of staphylococcus that is protein A rich (Cowan I), but not protein A deficient (Woods 46). C1q binding levels were also increased in normal and tumor-bearing canine or human sera which were perfused over purified protein A immobilized in collodion charcoal (PACC), and this increase was localized in sucrose density gradient fractions ranging from 7S to 19S. Polyacrylamide gel electrophoresis analysis of the high-molecular-weight fraction in postperfusion canine sera, isolated by G-200 fractionation and immunoaffinity chromatography, showed predominantly heavy and light immunoglobulin chains of canine IgG. Furthermore, protein A was released from PACC after perfusion with serum or solutions containing IgG or albumin from humans, dogs, and chickens. After serum perfusion over PACC, protein A was identified in the effluent by additional studies as follows: (a) polyacrylamide gel electrophoresis analysis showed that eluted 125I-protein A comigrated with the protein A marker; (b) postperfusion C1q-binding complexes, isolated by gel filtration under dissociating conditions and affinity chromatography on IgG-Sepharose showed a single precipitin band with normal human (protein A reactive) but not chicken (protein A unreactive) serum. Protein A released from PACC which appeared in postperfusion sera was associated with immunoglobulins in macromolecular complexes since (a) eluted 125I-protein A was largely (NH4)2SO4 and polyethylene glycol precipitable, whereas free protein A was not, and it sedimented in sucrose density gradient fractions distributed beyond the 7S marker, compared to free protein A which localized below 7S; (b) radiolabeled protein A eluting from PACC after serum perfusion showed 8-fold greater binding to C1q-coated tubes compared to free protein A; and (c) increased C1q-binding IgG in postperfusion sucrose density gradient fractions corresponded to the appearance of protein A in parallel gradient fractions.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗
PubMed1983

Perfusion of canine serum over Staphylococcus aureus Cowan 1: Evidence for release of protein A and changes in specific antibody activity.

Sera from three normal dogs were assessed for levels of Clq binding IgG and complement consumption after perfusion over Staphylococcus aureus Cowan I (SAC). Increased levels of Clq binding IgG were detected after perfusion of sera over SAC and were associated with complement consumption. Canine antiserum to human erythrocytes were also perfused over SAC and assessed for Clq binding IgG and hemolytic activity. Increased levels of Clq binding IgG in post-perfusion samples were detected which were associated with a decrease in hemolytic activity. IgG was determined to be present in molecular weight fractions greater than 200,000 M.W. in post-perfusion chromatographically fractionated sera. Moreover, 5% polyethylene glycol (PEG) precipitated IgG from post-perfusion sera was functional in antibody dependent cellular cytotoxicity assays. Putative staphylococcal protein A isolated from post-perfusion sera produced a precipitin band in double diffusion agarose gel studies when reacted with normal human and canine sera. A polypeptide co-migrating with purified protein A could be detected by polyacrylamide gel electrophoresis (PAGE) analysis of the post-perfusion isolated protein A. Addition of purified protein A to canine antiserum resulted in decreased hemolytic activity of the serum which was associated with increased levels of Clq binding IgG.

Animals↗
PubMed1982

Detection of Raji binding activity in hyperimmune allogeneic tumor bearing sera associated with anti-BSA activity.

Brown Norway (BN) rats were implanted twice with allogeneic (Lewis strain) Moloney sarcoma tumors (LM-2) and serum samples were assessed for Raji binding activity during primary and secondary tumor growth and rejection. Maximum Raji binding was observed 25 days after a primary tumor implant; thereafter, the binding activity decreased. Accelerated tumor rejection was observed after a second tumor implant and was associated with a 3-fold increase in serum Raji binding activity which remained elevated up to 40 days post-tumor implant. Raji binding activity in hyperimmune rats co-migrated with IgG in G-200 fractionated serum. Polyacrylamide gel electrophoresis (PAGE) revealed the presence of bovine serum albumin (BSA) on Raji cell membranes which reacted immunochemically with rabbit anti-BSA antiserum. Immunodiffusion studies revealed that sera from hyperimmune rats produced a precipitin band when reacted with Noniodet P-40 (NP-40) lysates of Raji cells and formed a line of identity with BSA.

Animals↗
PubMed1982

Isolation of human IgA utilizing protein A affinity chromatography.

Human serum IgA was isolated employing a system of G-200 column chromatography, anion exchange (DE-52) chromatography, and passage over protein A and anti-IgG Sepharose 4B columns. Polyacrylamide gel electrophoresis (PAGE) analysis of the isolated immunoglobulin revealed polypeptides corresponding to alpha and light immunoglobulin chains of IgA which were identified immunochemically as IgA. Ultracentrifugation studies revealed that the isolated immunoglobulin co-migrated with 7S IgG markers. This procedure may serve as an alternative to classical isolation procedures of IgA from human serum.

Centrifugation, Density Gradient↗
PubMed1982

IgA containing immune complexes in dogs bearing a spontaneous mammary adenocarcinoma.

Sera from dogs with mammary adenocarcinoma were assessed for the presence of immune complexes (IC) and the physicochemical composition of these complexes was investigated. Employing 125I-anti-canine IgG as indicator, elevated levels of C1q binding IgG were detected in sera of dogs with mammary adenocarcinoma. Polyacrylamide gel electrophoresis (PAGE) analysis of IC isolated by G-200 fractionation and protein A affinity chromatography revealed the presence of a dense polypeptide band corresponding to the alpha chain of IgA which was present in the mammary adenocarcinoma sera but not in normal dog sera or sera from dogs with other tumours. Employing monospecific radiolabelled anti-canine IgA as indicator in solid phase C1q binding radioimmunoassays, significantly elevated levels of C1q binding IgA were detected in five of eight mammary adenocarcinoma sera but not in sera of normal dogs or other tumour bearing dogs (P less than 0.05). Sera from mammary adenocarcinoma bearing dogs treated with 5% polyethylene glycol (PEG) and subjected to sucrose density gradient ultracentrifugation revealed IgA containing IC in fractions greater than 7S to greater than 19S. Findings suggest that IC are present in sera of dogs with mammary adenocarcinoma and that that IgA is a major and unique component of these complexes and, hence, may play a significant role in the development and evolution of the canine immune response to mammary adenocarcinoma.

Animals↗
PubMed1977

Adoptive transfer of immunity from mice immunized with ribosomes or live yeast cells of Histoplasma capsulatum.

This investigation was designed to compare the role of lymphoid cells and immune serum in protective immunity induced by immunization with ribosomes or live yeast cells of Histoplasma capsulatum. Spleen cells, peritoneal cells, and serum from C3H mice immunized with Histoplasma ribosomes or live cells were transferred intravenously to separate groups of syngeneic recipients. All recipients along with a set of immunized and control mice were challenged intravenously with 4 x 10(6) yeast cells of H. capsulatum, and protection was assessed. Immunization with ribosomes or live cells provided 90 to 100% protection. Mice receiving filtered spleen cells or peritoneal cells from donors immunnized with live cells showed 90 to 100% protection; 80 to 90% protection was observed for mice receiving cells from ribosome-immunized donors. In contrast, no evidence of protection was seen in mice receiving serum from either live-cell- or ribosome-immunized mice. Peritoneal cells were far more efficient than spleen cells in adoptive transfer of immunity. The adoptive immunity in recipients persisted for at least 3 weeks after transfer, the longest period tested in the present study. These results indicate that the immunity elicited by immunization with Histoplasma ribosomes or live cells is mediated by a cellular mechanism.

Animals↗
PubMed1977

Septicemia as a complication of percutaneous liver biopsy.

Three cases of septicemic shock after liver biopsy are reported. Escherichia coli was cultured in 2 patients and in 1 E. coli was cultured with Streptococcus viridans. All 3 patients were afebrile and had normal WBC counts before the procedure. Two had cholangitis and the 3rd had primary hepatoma and cirrhosis of the liver. Septicemic shock should be recognized as a rare complication of liver biopsy in patients with biliary obstruction.

Aged↗