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Biomedical subjects

M Gruber

Publications and source records attributed to M Gruber.

At least 19 recordsLinked to original sources
PubMed1995

Personality self-representations of patients with hand injury, and its relationship with work injury.

This study compared the personality self-representations of 288 hand injured patients with those of 959 young people (15-25 years old) randomly selected from the general population (noted GP), and with those of 336 unemployed people of all ages in professional training (U) in Lorraine (north-eastern France). The relationship between patients' personality self-representations and injury was also investigated. Personality self-representations included 14 questions: in your own opinion are you sociable?, at ease with others?, serious?, careful?, dynamic?, optimistic?, worried?, irritable?, clumsy?, solitary?, organised?, ambitious?, do you have a sense of responsibility?, and many plans? The patients had similar self-representations to GP except for the items non clumsy (odds ratio adjusted on age and sex OR = 2.40, p < 0.05) and optimistic (OR = 1.70, but 0.05 < p < 0.10). The frequencies of non irritable, non clumsy and non solitary people were higher in patients than in the U group (OR about 2.40, p < 0.01). By contrast, the other items were more favourable for the U group except for the items sociable, organised and having many plans. Self-representation items were significantly related to some socio-demographic data. The work injured workmen having one or more previous work injuries during the last five years were more at ease with others than the other subjects. Among the work injured workmen who had had no previous work injury during this time, the people aged 29 or less (the highest risk age class) were more optimistic than the others (71% vs 49%, p < 0.05); a difference was also found for the items at ease with others, careful, dynamic, and non worried, but it was not significant possibly due to the small number of subjects. The sum of these five items differed between the two age groups (3.29 +/- 1.49 vs 2.55 +/- 1.68, p < 0.05). These simple items would provide an interesting approach in terms of personality which could explain in part the excess of work injuries in young people, though the work requirement still seemed to be the highest risk factor.

Accidents, Occupational↗
PubMed1995

Properties of bispecific single chain antibodies expressed in Escherichia coli.

Single chain bispecific antibodies, in which the genes that encode the VH and VL regions are linked in tandem, may offer some advantages over other methods of bispecific antibody preparation. To begin to evaluate the potential of this system, a single chain bispecific antibody (scFv2) that binds to the T cell receptor of a cytotoxic T cell clone and to the hapten fluorescein was constructed. The individual scFv regions were joined by a 25 amino acid linker, and the scFv2 protein was obtained from insoluble inclusion bodies after guanidine solubilization and refolding. Fluorescein-purified scFv2 is active at concentrations of approximately 10 nM (approximately 1 microgram/ml) and above in mediating lysis of fluorescein-coupled tumor cells by the cytotoxic T lymphocytes (CTL). This system has now been used to evaluate various features of the scFv2 approach: (a) affinities of the scFv2 for the TCR and fluorescein, (b) yields of the scFv2 from several different purification schemes, (c) relationship of antigen density (i.e., fluorescein density on tumor cells) to the ability to redirect lysis of the tumor cell, and (d) relationship of scFv2 affinity for the tumor antigen to the ability to redirect lysis. This study was performed by using several analogs of fluorescein for which the scFv2 had different affinities. Results showed that it should be possible to select antibodies with appropriate affinities such that tumor cells with typical antigen densities of 10(4)-10(5) molecules per cell will be lysed and normal cells that have lower levels of the antigen will be spared.

Animals↗
PubMed1994

Efficient tumor cell lysis mediated by a bispecific single chain antibody expressed in Escherichia coli.

Recent advances in the expression of Abs in Escherichia coli have raised the possibility that virtually any specificity can be obtained by either cloning Ab genes from characterized hybridomas or by de novo selection using Ab gene libraries. Bispecific Abs have been more difficult to engineer because of problems inherent in the proper folding and association of VH and VL domains. In this report, a model system for expressing and testing the activity of a single chain bispecific Ab was used. The Ab contained the VH and VL genes from the anti-TCR Ab 1B2 joined by a 25 amino acid residue linker to the VH and VL genes from the anti-fluorescein Ab 4420. The 57-kDa single chain bispecific Ab (scFv2) was purified in a single step by affinity chromatography through a fluorescein column at a yield of 1 mg/L of bacterial culture. Despite the presence of 1B2 V regions at the NH2-terminus and a 10-residue c-myc peptide at the COOH-terminus, the refolded protein had an affinity for fluorescein that was nearly identical with the monospecific single chain Ab. The scFv2 also bound the TCR of the mouse CTL clone 2C and redirected the lysis of human tumor cells that had fluorescein covalently linked to their surface. Lysis was mediated at scFv2 concentrations that were 100-fold lower than the concentrations of Ab that inhibited normal recognition by CTL 2C. These results show that single chain bispecific Abs can mediate CTL lysis of target cells without the immunosuppressive side effects associated with the use of anti-TCR Abs.

Amino Acid Sequence↗
PubMed1994

Chemo-somatosensory event-related potentials in response to repetitive painful chemical stimulation of the nasal mucosa.

The aim of the study was to investigate how chemo-somatosensory event-related potentials (CSSERPs) and pain ratings are modified by repetitive painful stimulation of the nasal mucosa (58% v/v CO2, 200 msec duration). Twenty-two subjects performed 3 experiments during which trains of stimuli were applied. The interstimulus interval (ISI) between stimuli was constant for each experiment, but varied between experiments (8, 4, and 2 sec). CSSERPs were obtained from 5 positions (Fz, C3, Cz, C4, and Pz). The subjects not only rated the overall perceived intensities but also reported the quality of the stimuli. At an ISI of 8 sec estimates decreased and only stinging sensations were reported. In contrast, at an interval of 2 sec estimates increased being accompanied by the buildup of burning pain. This phenomenon was interpreted in terms of the superposition of first (sharp and stinging pain: A delta fibers) and second pain (dull and burning pain: C fibers), respectively. However, given the special circumstances of short ISIs CSSERP amplitudes decreased the more the shorter the ISI was. In line with previous investigations it is hypothesised that CSSERPs predominantly reflect nociceptive information transmitted via A delta fibers.

Adult↗
PubMed1994

Dose-related effects of ibuprofen on pain-related potentials.

1. The aim of this study was to investigate the dose-related effects of ibuprofen (placebo, 400 and 800 mg rac-ibuprofen [Aktren], administered orally) on experimentally-induced tonic and phasic pain. 2. Eighteen volunteers participated in this randomized, double-blind, three-fold cross-over study. Measurements were obtained before and 90 min after administration of the drugs. Phasic pain was produced by CO2 pulses of two concentrations applied to the right nostril. The left nostril was stimulated with a constant stream of dry air which produced a tonic painful sensation described as dull and burning. Subjects rated the intensity of the painful stimuli by means of visual analogue scales. In addition, chemo-somatosensory event-related potentials (CSSERP) were also recorded in response to phasic painful CO2 stimuli. 3. While mean intensity estimates of both tonic and phasic painful stimuli showed a non-significant dose-related decrease, a statistically significant dose-related decrease was observed for CSSERP amplitudes. 4. In conclusion, in order to investigate analgesic drug effects, CSSERP appear to be a more sensitive measure compared with psychophysically obtained responses.

Adult↗
PubMed1993

Pilot study of natural human interleukin-2 in patients with chronic hepatitis B. Immunomodulatory and antiviral effects.

Ten patients with chronic hepatitis B received increasing doses of nIL-2 (30,000 U, 100,000 U, 300,000 U, 1.0 million U) subcutaneously in a phase I trial. Each dose was applied once per week over 3 weeks. Serum samples were taken before and 2, 12, 24, 48 and 72 h after the first application of each dose level. Serum concentrations of interleukin-1 (IL-1), IL-2, IL-6, interferon-alfa (IFN-alpha), IFN-gamma, tumor necrosis factor-alpha (TNF-alpha) and GM-CSF as well as the cytokine-dependent serum components neopterin, beta-2-microglobulin (B2M), C-reactive protein (CPR), soluble IL-2-receptor (sIL-2R) and 2'-5'-oligoadenylate synthetase (2-5 OA) were assayed using ELISAs and RIAs. None of the samples tested contained measurable cytokine levels other than IL-2. A low and non-toxic dose of 300,000 U nIL-2 was already biologically active with induction of neopterin, B2M and sIL-2R. Dose-dependent changes peaked 24-48 h after application. The same patients were then enrolled in a phase II trial. Treatment in five of the patients was continued twice per week for 3 months with a biologically active dose of 300,000 U nIL-2 subcutaneously. Two of these patients as well as another five patients from the original group were treated with 1.0 million U nIL-2 subcutaneously, twice weekly for 3 months. Neither a biologically active but non-toxic dose of 300,000 U nIL-2, nor a toxic dose of 1.0 million U resulted in permanent clearance of hepatitis B early antigen (HBeAg).(ABSTRACT TRUNCATED AT 250 WORDS)

2',5'-Oligoadenylate Synthetase↗
PubMed1993

Post-traumatic stress disorder and GI endoscopy: a case study.

Post-traumatic stress disorder (PTSD) can be caused by experiencing or witnessing a variety of harsh traumatic events. Rape, burglary, war, torture, violence, and other catastrophic events have been known to precipitate flashbacks, nightmares, and inability to cope with the demands of daily life. The symptoms associated with PTSD can interfere with work, sleep, appetite, relationships, and health. In a Veterans Administration hospital population, PTSD is not an uncommon patient problem: it usually results from witnessing and/or participating in war or military service-related circumstances. This case study describes a 42-year-old man who was a prisoner of war in Vietnam. The form of torture his Vietnamese captors subjected him to presented a challenging situation when he required an endoscopic examination of the upper gastrointestinal tract. The purpose of this case study is to offer suggestions to the GI and endoscopy nursing staff who care for these patients, and to make GI health care providers aware of the special needs of this patient population.

Adult↗
PubMed1993

The development of a position statement using the Delphi technique.

The need to develop practice-related documents in an accurate, efficient, and economical manner is the responsibility of the Board of Directors of the Society of Gastroenterology Nurses and Associates (SGNA). When the results of large, randomized, controlled, clinical trials are available, documents can be based on the information published in scientific literature. GI nursing, however, is in a novice phase regarding controlled research trials; thus, other methods of obtaining reliable information are required. The Delphi technique was selected to obtain the consensus of experts. The Delphi technique enables a free and open exchange of ideas while respecting the economics of a deficit budget. This article describes the Delphi process and the manner in which it was used to prepare the SGNA position statement, "Responsibilities of the Gastroenterology Registered Nurse related to Conscious Sedation."

Delphi Technique↗
PubMed1993

The clinical spectrum of cerebral amyloid angiopathy: presentations without lobar hemorrhage.

Cerebral amyloid angiopathy is a common cause of spontaneous lobar hemorrhage in elderly patients. We discuss seven patients with amyloid angiopathy presenting without major lobar hemorrhage. The patients' presentations fell into two groups: recurrent transient neurologic symptoms and rapidly progressive dementia. The cases with transient episodes had a spread of symptoms to contiguous body areas during episodes. Each had evidence of small hemorrhage or subsequent large hemorrhage in the cortical location corresponding to the symptoms, suggesting petechial hemorrhage with focal seizure as the cause of the transient spells. Three cases of dementia developed with relatively rapid time courses, progressing from intact baseline to profound dementia in spans of a few days to 2 years. Pathologic abnormalities, in addition to amyloid angiopathy, included patchy white matter demyelination and tissue loss, petechial cortical hemorrhages, cortical infarctions, and a variable degree of neuritic plaques and neurofibrillary tangles. The clinical spectrum of cerebral amyloid angiopathy includes these two neurologic syndromes.

Aged↗
PubMed1992

Continuous in vivo treatment with catecholamines suppresses in vitro reactivity of rat peripheral blood T-lymphocytes via alpha-mediated mechanisms.

A 20 h continuous treatment of rats with catecholamines, using subcutaneously implantable retard tablets, had either no (adrenaline, isoproterenol, midodrine) or a slight (noradrenaline) suppressive effect on the in vitro responsiveness of peripheral blood T-lymphocytes. A marked suppression of the mitogen response ensued when adrenaline, noradrenaline or midodrine, but not isoproterenol, was applied together with the beta-receptor blocker propranolol, whereas the combination with the alpha-receptor blocker phentolamine had no effect. The mitogen response of splenic lymphocytes was not affected by any of these treatments. This alpha-mediated adrenergic suppression of peripheral blood T-cells was not correlated with general metabolic alterations, shifts in white blood cell counts or CD4+/CD8+ subsets, or with elevated glucocorticoid levels. The data suggest that to consistently influence the reactivity of rat peripheral blood lymphocytes by chronic adrenergic stimuli in vivo requires both high catecholamine levels and a bias towards alpha-adrenergic receptivity.

Animals↗
PubMed1992

Seroprevalence of antibodies to the human immunodeficiency virus in dialysis workers: results of a multi-center study.

The Center for Devices and Radiological Health, in collaboration with the Department of Veterans Affairs Medical Center, Brooklyn, N.Y., conducted a multi-center, multi-institutional study of the seroprevalence of antibodies to the human immunodeficiency virus (HIV) among dialysis workers. Seven dialysis units and 112 dialysis workers participated in the study over a period of 2 years. Participation was limited to dialysis workers who, by questionnaire, denied non-occupational risk factors for HIV infection. The vast majority of the study participants were drawn from areas where the prevalence of HIV infection and AIDS cases are substantially greater than the national average. Study participants received the ELISA test for HIV antibodies. All 112 of the participants tested negative for HIV antibodies. These results are encouraging, as they failed to reveal unrecognized occupational transmission of HIV infection among dialysis workers.

HIV↗
PubMed1991

Regulatory elements and DNA-binding proteins mediating transcription from the chicken very-low-density apolipoprotein II gene.

The chicken Very-Low-Density Apolipoprotein II (apoVLDL II) gene is specifically expressed in liver in response to estrogen. In this study, we performed a functional analysis of the 300-base pair region immediately 5' to the gene by gene transfer of chloramphenicol acetyl transferase (CAT) constructs into chicken embryonic hepatocytes (CEH). Two estrogen response elements (EREs) could be distinguished which together form a potent estrogen response unit. Stimulation of transient expression by co-transfection with a plasmid expressing rat C/EBP confirmed that a similar protein in chicken liver may be involved in apoVLDL II transcription. In vitro DNaseI footprinting and band-shift analysis with liver, oviduct and spleen nuclear extract revealed the tissue distribution of the proteins binding to the promoter region. A liver-specific protein bound to multiple sites of which some resembled the recognition sequence of the CCAAT/Enhancer binding protein, C/EBP. Of the other proteins binding to the apoVLDL II promoter, one was identified as the liver-specific LF-A1 by mobility shift analysis, using purified bovine LF-A1, and another as the general COUP-transcription factor, using an antiserum against the human COUP-TF.

Animals↗
PubMed1991

Susceptibility contrast imaging of cerebral blood volume: human experience.

Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses high-speed "single-shot" or echo planar imaging techniques, which provide the necessary temporal resolution for mapping the rapid cerebral transit of contrast agents. These MR CBV mapping techniques have been used to study normal human brain task activation and in the clinical study of patients with brain tumors. In the latter, positron emission tomography imaging was used for functional metabolic and CBV correlation. Susceptibility contrast CBV imaging should allow us to improve our understanding of the relationship between the detailed physiology and morphology of the microvascular bed and functional attributes of the brain. These techniques can be applied to understanding fundamental questions of cognitive neuroscience and can aid in improving diagnostic sensitivity and specificity in various neuropathologies.

Brain↗
PubMed1991

Suppression of thyroid function by interferon-alpha 2 in man.

Profound biological changes occur in patients treated with interferon. Observations of endocrine changes prompted us to examine the effects of subcutaneous alpha-interferon administration in single doses on circulating levels of thyroid stimulating hormone, total thyroxine, and total triiodothyronine in 10 volunteers (5 healthy subjects and 5 patients with hepatitis C). Blood samples were taken on an out-patient basis immediately before and 2, 12, 24, 48, and 72 h after administration of 1, 3, or 5 x 10(6) units of recombinant alpha-interferon. Application of the different dose levels was randomly assigned. Plasma samples were stored at -80 degrees C; after collection of samples had been completed hormone levels were measured using commercially available test kits. At all time points before and after injection of alpha-interferon, standard deviations of measured hormone levels of healthy control subjects and patients overlapped to a considerable extent. At a dose level of 5 x 10(6) units, alpha-interferon significantly increased cortisol levels as described, and decreased the level of thyroid stimulating hormone in the group receiving alpha-interferon as compared to placebo-treated healthy volunteers. The effects occurred 12 h after injection. Maximum suppression of thyroid stimulating hormone levels was observed 24 h after injection, when serum levels of thyroxine and triiodothyronine also were significantly reduced. We conclude that subcutaneous alpha-interferon treatment with doses as low as 5 x 10(6) units affects the control of thyroid function.

Adult↗
PubMed1991

Palatability of colonic lavage solution is improved by the addition of artificially sweetened flavored drink mixes.

A frequent complaint of patients asked to drink polyethylene glycol (PEG) colonic lavage solution is the salty flavor. This often results in failure to ingest the entire 4 liters of the solution and compromises bowel cleansing. The purpose of this study was to determine systematically whether the addition of a flavored drink mix sweetened with aspartame to the PEG lavage solution would improve palatability without significantly altering the osmolality of the solution. Eighty-seven (87) staff volunteers participated in a taste test of PEG lavage solutions containing varying amounts of commercially available drink mixes. The solution containing two packages of lemon-flavored KoolAid drink mix sweetened with aspartame was significantly more palatable than the others (p less than 0.005), while osmolality remained within the range specified by the manufacturer of Colyte.

Colon↗
PubMed1991

Long-term enteral feeding: a retrospective comparison of delivery via percutaneous endoscopic gastrostomy and nasoenteric tubes.

The use of percutaneous endoscopic gastrostomy (PEG) tubes for enteral feeding is widespread, although their superiority to other feeding devices, such as nasoenteric tubes (NET), has not been substantiated. We retrospectively compared clinical outcomes in patients who received enteral feeding via PEG (n = 80) or NET (n = 29) from 1984 to 1988. Mean follow-up was 192 days in the PEG group and 141 days in the NET group. Changes in nutritional and performance status were similar in both groups. Aspiration pneumonia occurred within 14 days of tube placement in 6% and 24% (p = 0.01) of the PEG and NET patients, respectively. With the exception of tube replacement, cumulative rates of minor and major complications (including aspiration pneumonia) were similar in both groups during follow-up. None of the clinical variables that were assessed correlated with the development of aspiration pneumonia. Mortality was similar in both groups. These results suggest that, for long-term enteral feeding, PEG offers no substantial advantages over NET with respect to patient nutrition, performance, or survival. The reasons for the observed difference in short-term aspiration pneumonia rates are unknown, and must be investigated prospectively.

Aged↗