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Biomedical subjects

E Lutz

Publications and source records attributed to E Lutz.

At least 19 recordsLinked to original sources
PubMed1998

Rhodopsin-family receptors associate with small G proteins to activate phospholipase D.

G-protein-coupled receptors of the rhodopsin family transduce many important neural and endocrine signals. These receptors activate heterotrimeric G proteins and in many cases also cause activation of phospholipase D, an enzyme that can be controlled by the small G proteins ARF and RhoA. Here we show that the activation of phospholipase D that is induced by many, but not all, Ca2+-mobilizing G-protein-coupled receptors is sensitive to inhibitors of ARF and of RhoA. Receptors of this type were co-immunoprecipitated with ARF or RhoA on exposure to agonists, and the effects of GTP analogues on ligand binding to the receptor changed to a profile that is characteristic of small G proteins. These receptors contain the amino-acid sequence AsnProXXTyr in their seventh transmembrane domain, whereas receptors capable of activating phospholipase D without involving ARF contain the sequence AspProXXTyr. Mutation of this latter sequence to AsnProXXTyr in the gonadotropin-releasing hormone receptor conferred sensitivity to an inhibitor of ARF, and the reciprocal mutation in the 5-HT2A receptor for 5-hydroxy-tryptamine reduced its sensitivity to the inhibitor. Receptors carrying the AsnProXXTyr motif thus seem to form functional complexes with ARF and RhoA.

ADP-Ribosylation Factors↗
PubMed1997

Concentrations of copper, zinc and selenium in brain and kidney of second trimester fetuses and infants.

The concentrations of copper (Cu), zinc (Zn) and selenium (Se) in the brain and kidneys of second trimester fetuses (abortion cases) and infants (deceased before three months of age) were determined. Concentrations of Cu in brain, 0.31-1.6 mg/kg wet weight, increased with age, and were, on the average, three times higher in the brains of infants than of fetuses. In kidneys, Cu concentrations ranged between 0.34 and 2.9 mg/kg, and increased with age after birth. Concentrations of Zn in the brain decreased significantly with age in the fetuses, from about 7 mg/kg at post-conceptional week 12 to less than 5 mg/kg at week 20, but increased again postnatally. In kidneys, Zn concentrations (12-37 mg/kg) increased in parallel with the increase in tissue density. Concentrations of Se in brain, 0.072-0.14 mg/kg, decreased with age in the fetuses, but increased with age postnatally. Kidney Se concentrations (0.16-0.55 mg/kg) did not change significantly with age during the fetal period, but increased about 2.5 times during the postnatal period. There was a significant association between the concentrations (on molar basis) of Zn and Cu in kidneys, but not in brain. There was no correlation between the concentrations of Cu, Zn or Se and those of mercury, cadmium and lead, previously determined in the same samples, with the exception of mercury and Se in kidneys.

Brain↗
PubMed1996

Chromosomal localization in mouse and human of the vasoactive intestinal peptide receptor type 2 gene: a possible contributor to the holoprosencephaly 3 phenotype.

The neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) have been shown to act on a wide range of tissue and cell types, both in the central nervous system and in the periphery. Two distinct receptors for VIP, the VIP receptor type 1 (VIPR1) and the VIP receptor type 2 (VIPR2), have recently been cloned, each of which binds PACAP and VIP with equal affinity. We report here the chromosomal mapping of the human and mouse VIPR2 genes by fluorescence in situ hybridization. The VIPR2 gene maps to the human chromosomal region 7q36.3 and to the F2 region of mouse chromosome 12. Our localization of the human gene places it in the region where the locus for the craniofacial defect holoprosencephaly type 3 (HPE3) maps. Further mapping experiments, carried out on cell lines derived from patients with HPE or HPE microforms and associated 7q deletions, have led us to redefine the distal extent of the HPE3 minimal critical region, originally characterized by Gurrieri et al. (1993, Nature Genet. 3: 247-251.) The VIPR2 gene lies within this new HPE3 minimal critical region. Our results suggest that deletion of the VIPR2 gene is not the sole factor responsible for the HPE3 phenotype. However, it is possible that monosomy at the VIPR2 locus may contribute to the phenotype observed in many cases of HPE3.

Animals↗
PubMed1996

Cytomegalovirus antibody avidity in allogeneic bone marrow recipients: evidence for primary or secondary humoral responses depending on donor immune status.

The reconstitution of the human cytomegalovirus (CMV) antibody response in CMV seropositive bone marrow transplant patients was investigated by comparing 11 patients whose donors were CMV seropositive with 8 whose donors were CMV seronegative. Evidence for primary or secondary responses to CMV was sought by determining IgG antibody avidity using an avidity index method, and antibody titre over a period of up to 3 years after transplant. For the patients whose donors were CMV seropositive, the results showed the characteristics of a secondary response, i.e., rising antibody titres of high avidity immediately after transplant. In contrast, the patients with CMV seronegative donors showed evidence of a primary antibody response usually occurring at about 250 days after transplant, i.e., rising antibody levels initially of low avidity maturing to high avidity over the following 100 to 200 days. It is concluded that a secondary response and hence transfer of humoral immunity had occurred in those patients whose donor was CMV seropositive, whereas a delayed primary response occurred in those patients whose donor was CMV seronegative.

Antibodies, Viral↗
PubMed1996

Concentrations of mercury, cadmium and lead in brain and kidney of second trimester fetuses and infants.

The concentrations of mercury (Hg), cadmium (Cd) and lead (Pb) in brain (cerebrum) and kidney during fetal (second trimester terminations or abortions, n = 20) and postnatal (infants deceased before three months of age, n = 15) development have been studied. Information on possible sources of exposure was obtained from the mothers of the fetuses, but not from those of the infants. The median concentration of Hg in the brain was 4 micrograms/ kg wet weight in both fetuses and infants (total range < or = 2-23 micrograms/kg). The concentrations of Hg in the kidneys were significantly higher than in brain, median of Hg 6 micrograms/kg (range < or = 5-34 micrograms/kg) in fetuses and 10 micrograms/kg (< or = 7-37) in infants. There was a tendency of increasing concentration of Hg in the fetal kidney, but not in the brain, with increasing number of amalgam fillings in the mothers. The concentration of Cd in the brain was less than 1 microgram/kg in most cases, both in fetuses and infants. The concentration of Cd in the kidneys was significantly higher, with a median of about 2 micrograms/kg (1-8 micrograms/kg) in both groups. There was no detectable association between tissue Cd concentrations and the smoking habits of the mothers. The concentration of Pb in brain was below 10 micrograms/kg in most cases. In the kidneys, the concentrations of Pb were significantly higher, with a median of 12 micrograms/kg in the fetuses (range < or = 6-20 micrograms/kg) and 15 micrograms/kg (< or = 9-36 micrograms/kg) in the infants. In general, the concentrations of Cd and Pb were lower than in previously reported studies.

Brain Chemistry↗
PubMed1994

Maturation of antibody avidity after primary human cytomegalovirus infection is delayed in immunosuppressed solid organ transplant patients.

An IgG antibody avidity assay which uses urea to modify a commercial enzyme-linked immunosorbent assay (ELISA) has been investigated for its ability to distinguish primary human cytomegalovirus (CMV) from recurrent or long-term infection. Twenty-four immunosuppressed solid organ transplant patients were studied. The avidity indices for IgG to CMV were low for 12 out of 13 patients with primary infection (mean 18%), high for all 11 patients with long-term infection (mean 85%), and the 1 patient with primary infection showing an intermediate avidity index (51%) was found to have acquired passively large amounts of CMV immunoglobulin, presumably of high avidity, during therapy. From the results, low and high avidity indices were defined as lying between 0-34% and 60-100%, respectively, and it was thus clear that the avidity assay can discriminate between primary and recurrent or long-term CMV infection. The avidity indices of eight of the immunosuppressed organ transplant patients with primary infection were followed in serial serum samples over time and IgG antibody to CMV was found to take at least a year to mature to high avidity in contrast to the 2-6 months expected for normal subjects. This finding provides evidence that immunosuppression has subtle, hitherto unsuspected, effects on humoral immunity to CMV in addition to the well-known depression of cell-mediated responses. It is concluded that this reliable avidity assay will be of importance in the diagnosis of CMV infection and in elucidating the pathogenesis of CMV-induced disease in organ transplant recipients.

Adult↗
PubMed1993

Allogeneic bone marrow transplantation for chronic myeloid leukemia using sibling and volunteer unrelated donors. A comparison of complications in the first 2 years.

OBJECTIVE: To compare the short- and medium-term complications (particularly infection) of bone marrow transplantation for chronic myeloid leukemia in patients with HLA-identical sibling donors or volunteer unrelated donors. DESIGN: Retrospective review of two cohorts of patients. SETTING: Tertiary referral center. PATIENTS: One hundred three patients with chronic myeloid leukemia in first chronic phase. INTERVENTION: Patients were treated with bone marrow transplantation using marrow from HLA-identical siblings (n = 57) and volunteer donors (n = 46). MAIN RESULTS: In total, 68 patients survived a median of 22 months from bone marrow transplant (range, 7 to 81 months). The actuarial probabilities of overall survival and leukemia-free survival at 2 years for the sibling donor group were 73% (95% CI, 60% to 86%) and 72% (CI, 60% to 84%), respectively, and for the volunteer donor group, 47% (CI, 31% to 63%) and 42% (CI, 26% to 58%) (P = 0.07 and 0.05, respectively). However, after adjustment for duration of disease, overall and disease-free survival in the two donor groups did not differ significantly. A major problem was an increased incidence of severe viral infection in the volunteer unrelated donor group (19 episodes in 16 of 46 patients compared with 7 episodes in 7 of 57 sibling donor patients, P = 0.01). The actuarial incidence of chronic graft-versus-host disease (GVHD) was higher in volunteer unrelated donor patients (77% [CI, 63% to 91%] compared with 49% [CI, 35% to 63%]; P = 0.02) but that of acute GVHD was not. The median performance status of the survivors in the volunteer donor group is similar to that in the sibling donor group. The incidence of hematologic relapse in both groups so far is low. CONCLUSION: Results appear to justify the continued use of volunteer donors in chronic-phase chronic myeloid leukemia, but infection and chronic GVHD are still major problems.

Actuarial Analysis↗
PubMed1987

[Campylobacter pylori--is there a connection with peptic ulcer?].

In 67 patients, mucosal biopsies were taken in gastroduodenoscopy and culture set up to demonstrate Campylobacter pylori. Campylobacter pylori was cultured from 91% of the patients with peptic ulcer, in 76% of patients with gastritis and in 28% of patients without histological detection of gastritis. Electron microscopic investigations of duodenal mucosa showed that this bacterium attaches to the metaplastic cells of the antral type. This cell type is regularly encountered in the duodenal mucosa in healing duodenal ulcer. The ultrastructural features permit a clear distinction between Campylobacter pylori and other Campylobacter species. Campylobacter pylori may possibly have a pathogenic effect on the mucosa owing to its penetration into the interstitial spaces between the cells and into the interior of the cells.

Adult↗
PubMed1979

Nurse/physician reactions to 'swing beds'.

Providing long-term care in acute care beds--the swing-bed concept--fills a community health care need and helps the small hospital financially. But more than the status of the bed changes as medical and nursing staffs must adjust their daily schedules and attitudes. Day-to-day problems encountered by the hospital staff are detailed, as well as some recommendations for the future.

Attitude of Health Personnel↗
PubMed1976

[Specific and non-specific effects of beta-adreno-receptor blocking drugs in man (author's transl)].

The effect of tyramine infusion or exercise on catecholamine concentration and dopamine-beta-hydroxylase activity in plasma of normal volunteers has been studied. Whereas the increase in plasma catecholamine concentrations by tyramine infusion was not changed 90 min after oral application of a single dose of beta-adrenoceptor blocking drugs (penbutolol, practolol, I.C.I. 66082), the increase in blood pressure was diminished. However, the increase in plasma catecholamine, concentration, i.e. the adrenergic response to exercise was significantly enhanced during beta-adrenoceptor blockade. On the other hand, dopamine-beta-hydroxylase activity was not further increased during beta-adrenoceptor blockade. - The non-specific membrane activity of the beta-adrenoceptor blocking drugs wass assessed by the degree of inhibition of serotonin uptake by human platelets in vitro. Their order of potency, according to IC 50 values estimated from the dose response curves was: propranolol less than penbutolol less than practolol less than I.C.I. 66082. The inhibitory activity of these drugs in vivo was also studied by measuring serotonin uptake by platelets isolated 90 min after oral administration. Due to the high dose only propranolol showed a marked membrane activity.

Adrenergic beta-Antagonists↗