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Biomedical subjects

G Bender

Publications and source records attributed to G Bender.

At least 19 recordsLinked to original sources
PubMed2006

Distinct roles for spinophilin and neurabin in dopamine-mediated plasticity.

Protein phosphatase 1 plays a major role in the governance of excitatory synaptic activity, and is subject to control via the neuromodulatory actions of dopamine. Mechanisms involved in regulating protein phosphatase 1 activity include interactions with the structurally related cytoskeletal elements spinophilin and neurabin, synaptic scaffolding proteins that are highly enriched in dendritic spines. The requirement for these proteins in dopamine-related neuromodulation was tested using knockout mice. Dopamine D1-mediated regulation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor activity was deficient in both striatal and prefrontal cortical neurons from neurabin knockout mice; in spinophilin knockout mice this deficit was manifest only in striatal neurons. At corticostriatal synapses long-term potentiation was deficient in neurabin knockout mice, but not in spinophilin knockout mice, and was rescued by a D1 receptor agonist. In contrast, long-term depression was deficient in spinophilin knockout mice but not in neurabin knockout mice, and was rescued by D2 receptor activation. Spontaneous excitatory post-synaptic current frequency was increased in neurabin knockout mice, but not in spinophilin knockout mice, and this effect was normalized by D2 receptor agonist application. Both knockout strains displayed increased induction of GluR1 Ser(845) phosphorylation in response to D1 receptor stimulation in slices, and also displayed enhanced locomotor activation in response to cocaine administration. These effects could be dissociated from cocaine reward, which was enhanced only in spinophilin knockout mice, and was accompanied by increased immediate early gene induction. These data establish a requirement for synaptic scaffolding in dopamine-mediated responses, and further indicate that spinophilin and neurabin play distinct roles in dopaminergic signal transduction and psychostimulant response.

Animals↗
PubMed2005

Prenatal diagnosis of Bruck syndrome.

Bruck syndrome is an autosomal recessive connective tissue disorder combining features of osteogenesis imperfecta and arthrogryposis multiplex congenita. There are only few reports describing this rare syndrome of multiple fractures and joint contractures that is thought to be a subtype of osteogenesis imperfecta. We report the first case of prenatal diagnosis of this syndrome in a fetus at 23 weeks of gestation. Ultrasound findings included brachycephaly, retrognathia marked shortening and bowing of both femurs, bilateral fixed flexion of the elbows, bilateral fixed extension of the wrists and partially fixed flexion of the knees. The parents opted for termination of pregnancy. Macroscopic and radiologic examination of the aborted fetus confirmed the prenatal diagnosis, whereas morphological studies of the bone tissue found no hard evidence of osteogenesis imperfecta, probably due to the early stage of pregnancy and the heterogeneity of the syndrome itself.

Abortion, Induced↗
PubMed2001

Evidence for the neural crest origin of turtle plastron bones.

The migrating cranial neural crest cells of birds, fish, and mammals have been shown to form the membranous bones of the cranium and face. These findings have been extrapolated to suggest that all the dermal bones of the vertebrate exoskeleton are derived from the neural crest ectomesenchyme. However, only one group of extant animals, the Chelonians, has an extensive bony exoskeleton in the trunk. We have previously shown that the autapomorphic carapacial and plastron bones of the turtle shell arise from dermal intramembranous ossification. Here, we show that the bones of the plastron stain positively for HNK-1 and PDGFRalpha and are therefore most likely of neural crest origin. This extends the hypothesis of the neural crest origin of the exoskeleton to include the turtle plastron.

Animals↗
PubMed2001

Haemodynamic effects of valsartan in acute renal ischaemia/reperfusion injury.

BACKGROUND: Acute deterioration of renal function is an important side-effect of angiotensin-converting enzyme (ACE) inhibitors, especially if accompanied by other nephrotoxic events. Angiotensin II receptor(1) blockers (ARB) are thought to have fewer side-effects on renal perfusion and function. We examined the effects of valsartan (VAL) on kidney function as well as the contribution of the nitric oxide (NO) system in a rat model of ischaemic acute renal failure (ARF). METHODS: ARF was induced by 40 min of clamping of both renal arteries in female Sprague-Dawley rats. Renal haemodynamic and tubular parameters were determined during post-ischaemic infusion of vehicle, VAL, VAL and the NO-synthase substrate L-arginine, and VAL together with inhibition of NO synthases (NOS) by L-NMMA. RESULTS: Clamping induced acute renal failure with marked decreases in glomerular filtration rate (GFR) and renal plasma flow (RPF) accompanied by a rise in renal vascular resistance (RVR) and fractional sodium excretion. Valsartan caused a slight but significant improvement of GFR and RPF without full recovery of renal function and caused a lowering of RVR and tubular sodium loss. L-arginine-co-administration had no additive beneficial effect. Valsartan-induced changes were not significantly depressed by unspecific inhibition of NOS. CONCLUSIONS: Inhibition of the angiotensin II-receptor(1) diminishes the deleterious effects of ischaemia and reperfusion on glomerular function and on the renal microcirculation. An involvement of the NO system could not be demonstrated.

Acute Disease↗
PubMed1995

Transcriptional activation by tetracyclines in mammalian cells.

A transcriptional transactivator was developed that fuses the VP16 activation domain with a mutant Tet repressor from Escherichia coli. This transactivator requires certain tetracycline (Tc) derivatives for specific DNA binding. Thus, addition of doxycycline to HeLa cells that constitutively synthesized the transactivator and that contained an appropriate, stably integrated reporter unit rapidly induced gene expression more than a thousandfold. The specificity of the Tet repressor-operator-effector interaction and the pharmacological characteristics of Tc's make this regulatory system well suited for the control of gene activities in vivo, such as in transgenic animals and possibly in gene therapy.

Amino Acid Sequence↗
PubMed1989

[Early manifestation of severe gestosis (pre-eclampsia) in fetal triploidy--diagnosis and obstetrical management].

A case is reported of early-onset pre-eclampsia combined with severe malformations including holoprosencephaly and hydrocephaly caused by triploidy. By ultrasonic diagnosis, maternal risks caused by either prolonged pregnancy because of immaturity or inappropriate obstetrical management, i.e. by caesarean section, could be avoided. Ventriculocentesis of the macrocephalic fetus was performed and abortion induced.

Abnormalities, Multiple↗
PubMed1989

[Surgical management of lumbar spondylolisthesis].

The basic principles of the operative treatment of lumbar spondylolisthesis became uniform in the literature in the last years. Authors deal shortly with some questions of the indication and of the preoperative examination and describe shortly the basic principles of the operative treatment (decompression, reduction, stabilization). The operative methods used by them are reported and illustrated (Morscher's "hookscrew" method, fusion according to Harrington-Vidal, Cloward's posterior corpodesis--PLIF--and Steffee's transpedicular system).

Humans↗
PubMed1988

In vitro effects of low intensity direct current generated silver on eukaryotic cells.

An examination of the effects of low intensity direct current generated silver, (LIDC Ag) on several types of eukaryotic microorganisms and cell culture lines suggests that LIDC Ag has an appropriate selective toxicity for prokaryotic cells. It appears that levels of this agent could be obtained clinically that would have marked bacteriostatic activity and yet have little or no effect on mammalian cells.

Animals↗
PubMed1987

Inhibitory and cidal antimicrobial actions of electrically generated silver ions.

One promising alternative to antibiotics in the treatment of localized infections is the generation of antimicrobial silver ions by the use of low intensity direct current from a pure silver anode implanted at the site of an infection. This study investigates the in vitro bacteriostatic and bactericidal properties of this system on a variety of organisms.

Actinomyces↗
PubMed1981

[Polyarthrosis of the hand (author's transl)].

The polyarthrosis of the hand is a typical disease of the old age. Its banal form is more frequent in women, its erosive type in men. It can be demonstrated not only on the interphalangeal joints but on the metacarpophalangeal joints as well. The degenerative process of the basal-joints of the first ray of the hand is often seen in polyarthrosis. Most frequently diagnostic problems are caused by the erosive arthrosis however first of all polyarthrosis has to be differentiated from the p.c.p.

Aged↗
PubMed1980

[Arthrosis of the first foot segment in aged patients (author's transl)].

Basing on x-ray and clinical examinations, the authors report on the incidence, distribution according to sex and age, and lateral localisation of arthrosis occurring in the first segment of the foot. The bilateral type of arthrosis mostly occurs as a result of hallux valgus and is seen in women. Furthermore, degnerative changes and structural modifications of the dislocated sesamoids are also frequent. Arthrosis associated with hallux rigidus is a degenerative process mainly found in men, which is exclusively unilateral. This degenerative process shows the classical clinical and x-ray signs pertaining to arthrosis

Age Factors↗
PubMed1977

Ebstein's anomaly: a report of 3 cases in the dog.

Three young unrelated dogs were diagnosed as having the canine counterpart of Ebstein's anomaly, an eponymic term for a cardiac malformation in man. All of the dogs had systolic murmurs in the tricuspid area, and all had radiographic evidence of cardiac enlargement, particularly of the right atrium. Electrocardiography indicated atrial disease or right atrial enlargement and right ventricular conduction defects. The defect was confirmed by means of cardiac catheterization in all 3 dogs. Open heart surgery was performed on 2 of the dogs--plastic reconstruction of the tricuspid annulus and placement of a prosthetic valve in 1 and closure of an atrial septal defect in the other; both of these dogs died (1 day and 1 month after surgery).

Animals↗