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Biomedical subjects

S Stahl

Publications and source records attributed to S Stahl.

At least 19 recordsLinked to original sources
PubMed2001

Expression of vascular antigens by bone cells during bone regeneration in a membranous bone distraction system.

An in vivo system of membranous bone formation during distraction has been investigated in order to follow cells that express vascular markers with the objective of understanding the neovascularization process. Concomitantly, sustained proliferation of preskeletal cells was achieved through the application of mechanical force. New capillaries and leading edges that arose by angiogenesis from the periosteal and mucosal surfaces and invaded the central zone of the regenerating distraction tissue temporally preceded the growth of delicate woven bone trabeculae from both edges of the cut bone. Concentrically arranged 'onion-like' configurations were abundant in paracentral zones and in association with mesenchymal condensations, suggesting their de novo formation in situ. Vascular specific markers, the angiopoietin receptor Tie-2 and factor VIII-related antigen (FVIIIrAg), were localized immunohistochemically in order to follow cells of vascular origin. Endothelial cells of the new capillaries, centrally located cells of the concentric configurations, pericytes, and most of the adjacent polygonal mesenchymal cells stained positively with specific antibodies to both antigens. Moreover, preosteoblasts and osteoblasts that lie adjacent to or already embedded in the osteiod of the newly formed trabeculae were also FVIIIrAg and Tie-2 immunopositive. As the source of the bone-forming cells in regenerating tissue during distraction is not yet fully understood, this observation might support the possibility of their vascular origin.

Animals↗
PubMed2001

Complications of K-wire fixation of fractures and dislocations in the hand and wrist.

Kirschner wire (K-wire) fixation of fractures and dislocations of the hand and wrist is a common procedure. Of the 590 K-wire fixations performed on 236 patients, 36 (15.2%) experienced complications which included osteomyelitis, tendon rupture, nerve lesion, pin tract infection, pin loosening or migration. There were no deep soft-tissue pin infections or pyarthrosis. Technical failure, mainly when the procedure was performed by residents, and poor patient compliance were the major causes of complications. K-wire fixation is a simple but demanding procedure that cannot be left to an inexperienced resident. Elimination of technical failure, supervision in the operating room, close monitoring, prompt treatment upon discovery of a complication, and improvement of patient compliance can reduce the rate of complications.

Bone Nails↗
PubMed2001

Rapid tryptophan depletion plus a serotonin 1A agonist: competing effects on sleep in healthy men.

In the present study, we hypothesized that the REM-suppressing effects of 5-HT(1A) receptor stimulation would counteract the REM-disinhibiting effects of rapid tryptophan depletion (RTD), and vice versa. We administered RTD plus ipsapirone (10 mg, p.o.) or RTD plus placebo to 10 healthy men. In contrast to our previous findings but partially consistent with other studies, RTD in combination with placebo did not produce a significant enhancement of any REM sleep measure. The combination of RTD and ipsapirone produced a significant suppression of REM sleep that was remarkably similar to the effect of ipsapirone alone. These data appear to deepen the mystery of variable and inconsistent RTD-induced responses in healthy subjects. In the case of REM sleep measures, this differs markedly from the consistent RTD-induced REM-disinhibiting effect seen in medicated depressed patients.

Adult↗
PubMed2001

A novel augmentation strategy for treating resistant major depression.

OBJECTIVE: Treatment-resistant depression is a significant public health concern; drug switching or augmentation often produce limited results. The authors hypothesized that fluoxetine could be augmented with olanzapine to successfully treat resistant depression. METHOD: An 8-week double-blind study was conducted with 28 patients who were diagnosed with recurrent, nonbipolar, treatment-resistant depression without psychotic features. Subjects were randomly assigned to one of three groups: olanzapine plus placebo, fluoxetine plus placebo, or olanzapine plus fluoxetine. RESULTS: Fluoxetine monotherapy produced minimal improvement on various scales that rate severity of depression. The benefits of olanzapine monotherapy were modest. Olanzapine plus fluoxetine produced significantly greater improvement than either monotherapy on one measure and significantly greater improvement than olanzapine monotherapy on the other measures after 1 week. There were no significant differences between treatment groups on extrapyramidal measures nor significant adverse drug interactions. CONCLUSIONS: Olanzapine plus fluoxetine demonstrated superior efficacy for treating resistant depression compared to either agent alone.

Ambulatory Care↗
PubMed2001

Tension-band arthrodesis of the small joints of the hand.

A review of 72 cases of tension-band arthrodesis in the small joints of the digits was conducted. Fusion was achieved in all joints with no complications apart from 2 cases of superficial infection. No failure of the hardware was noted, although hardware was removed in 5 patients after fusion was attained due to technical failure or pain. This technique provides immediate skeletal stability, thereby facilitating early digital motion and recovery.

Adult↗
PubMed2001

[The surgical treatment of fractures of the base of the fifth metacarpal bone].

Fractures of the base of the fifth metacarpal bone are relatively uncommon injuries. In contrast to similar fractures of the first metacarpal bone, various methods of treatment have been advocated. Some believe that cast immobilization or immediate unrestricted motion is a reliable method, while others recommend surgery and pinning or plate fixation. Fractures of the base of the fifth metacarpal bone are inherently unstable and inadequate reduction may result in pain, functional disability and osteoarthritic changes. We retrospectively reviewed 14 cases with intra-articular or extra-articular fractures of the base of the fifth metacarpal bone between the years 1991-1998. Patient treatment included closed reduction and percutaneous pinning using an image intensifier. Open reduction with multiple Kirschner pinning was implied in comminuted fractures and in cases when closed restoration of the articular surface was unfeasible. On follow-up examinations, all patients had good functional outcomes with no arthritic changes. We recommend reduction, restoration of the articular surface and pinning as the method of choice in the treatment of these fractures.

Adult↗
PubMed2001

The 'upside-down' radial head: a diagnostic challenge.

The author describes a rare, traumatic dislocation of the radial head in an 8 year old girl. Only four similar cases were found in the literature. The danger of misdiagnosis and the life-long disability can be avoided by careful examination of the post-reduction radiograph.

Child↗
PubMed2000

High-accuracy measurement of the magnetic moment anomaly of the electron bound in hydrogenlike carbon.

We present a new experimental value for the magnetic moment of the electron bound in hydrogenlike carbon (12C5+): g(exp) = 2.001 041 596 (5). This is the most precise determination of an atomic g(J) factor so far. The experiment was carried out on a single 12C5+ ion stored in a Penning trap. The high accuracy was made possible by spatially separating the induction of spin flips and the analysis of the spin direction. The current theoretical value amounts to g(th) = 2.001 041 591 (7). Together experiment and theory test the bound-state QED contributions to the g(J) factor of a bound electron to a precision of 1%.

Journal Article↗
PubMed2000

Mucolipidosis type IV is caused by mutations in a gene encoding a novel transient receptor potential channel.

Mucolipidosis type IV (MLIV) is a developmental neurodegenerative disorder characterized by severe neurologic and ophthalmologic abnormalities. The MLIV gene, ML4 (MCOLN1), has recently been localized to chromosome 19p13.2-13.3 by genetic linkage. Here we report the cloning of a novel transient receptor potential cation channel gene and show that this gene is mutated in patients with the disorder. ML4 encodes a protein, which we propose to call mucolipin, which has six predicted transmembrane domains and is a member of the polycystin II subfamily of the Drosophila transient receptor potential gene family. The role of a potential receptor-stimulated cation channel defect in the pathogenesis of mucolipidosis IV is discussed.

Amino Acid Sequence↗
PubMed2000

[Scaphoid fractures in children].

The scaphoid is the most common carpal bone fractured in adults. In children the fracture is distinctly uncommon. We present our experience with 23 children treated between 1987-1998, 19 of them with fractures in the distal third of the wrist; there were 11 avulsions, 4 waist fractures, and 12 were undisplaced. The mechanism of injury was a direct blow or a fall onto the outstretched hand. Immobilization in a plaster cast led to union in all except 1 case. Based on our experience and study of the literature, it is evident that scaphoid fractures, although uncommon, do occur. Thorough clinical and radiological examination of children with a forearm or wrist injury is important in detecting such fractures.

Accidental Falls↗
PubMed2000

Observation of the continuous stern-gerlach effect on an electron bound in an atomic Ion

We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus.

Journal Article↗
PubMed2000

Multicenter double-blind comparison of sertraline and desipramine for concurrent obsessive-compulsive and major depressive disorders.

BACKGROUND: Serotonin reuptake inhibitors (SRIs) have demonstrated consistent efficacy in the treatment of obsessive-compulsive disorder (OCD), while agents that are primarily norepinephrine reuptake inhibitors have not. Comparable efficacy has been demonstrated for SRI and non-SRI antidepressants in uncomplicated major depressive disorder (MDD). This multicenter trial is the first comparison of an SRI (sertraline) and a non-SRI antidepressant (desipramine) in the treatment of OCD with concurrent MDD. METHODS: One hundred sixty-six patients diagnosed using structured clinical interviews and recruited from 16 treatment sites were randomly assigned to double-blind treatment with either sertraline (up to 200 mg/d) or desipramine (up to 300 mg/d) over 12 weeks. Measures of severity of OCD and MDD symptoms, as well as adverse effects of the medications, were monitored over the course of the treatment period. RESULTS: Patients assigned to sertraline responded significantly better at end point on measures of OCD and MDD symptoms compared with patients assigned to desipramine. Sertraline was also associated with a significantly greater number of patients who achieved a "robust" improvement in OCD symptoms (> or =40% reduction) compared with desipramine. More patients receiving desipramine than sertraline discontinued treatment because of adverse events. CONCLUSIONS: The SRI sertraline was more effective in reducing MDD and OCD symptoms than the primarily norepinephrine reuptake inhibitor desipramine for patients with concurrent OCD and MDD.

Adrenergic Uptake Inhibitors↗
PubMed2000

Serotonin and anxiety: current models.

Evidence for the importance of the serotonin system in anxiety disorders has increased substantially in recent years. Although preclinical research has provided an important source of hypotheses, clinical work on the value of selective serotonin reuptake inhibitors (SSRIs) in these conditions has been particularly persuasive. In this paper, a number of models of serotonin in the anxiety disorders are reviewed, and the clinical advantages of the SSRIs in anxiety disorders are emphasized. Models of serotonin in anxiety disorders include: 1) a 'see-saw model'; 2) an 'amygdala model'; and 3) a 'basal ganglia model'. While any simplistic schema in this complex area must fail, these various models have some heuristic value for the clinician. From a clinical perspective, the availability of the SSRIs has proved a significant step forward in the treatment of the anxiety disorders such as panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, and social anxiety disorder (social phobia); certainly these agents offer several advantages over previously existing pharmacotherapeutic alternatives such as the benzodiazepines and tricyclic antidepressants.

Animals↗
PubMed2000

Hybrid external fixation in high-energy elbow fractures: a modular system with a promising future.

BACKGROUND: Severe, high-energy, periarticular elbow injuries producing a "floating joint" are a major surgical challenge. Their reconstruction and rehabilitation are not well documented. Therefore, the following reports our experience with treating such injuries caused by war wounds. METHODS: Seven adults with compound open peri- and intra-articular elbow fractures were treated in hybrid ring tubular fixation frames. After debridement, bone stabilization, and neurovascular reconstructions, early controlled daily movements were started in the affected joint. RESULTS: These seven patients had together seven humeral, five radial, and six ulnar fractures. All fractures united at a median time of 180 days. No deep infection developed. The functional end results assessed by the Khalfayan functional score were excellent in two, good in one, and fair in four of these severely mangled upper extremities. None was amputated. CONCLUSIONS: The Mangled Extremity Severity Score has been shown to be unable to provide a reliable assessment for severe high-energy limb injuries surgically managed with the modular hybrid thin wire tubular external fixation system. This hybrid system is a very useful addition to the surgical armamentarium of orthopedic trauma surgeons. It both allows complex surgical reconstructions and reduces the incidence of deep infections in these heavily contaminated injuries. The hybrid circular (thin wire) external fixation system is very modular and may provide secure skeletal stabilization even in cases of severely comminuted juxta-articular fractures on both sides of the elbow joint (floating elbow) with severe damage to soft tissues. This fixation system allows individual fixation of forearm bone fractures, thus allowing the preservation of pronation-supination movements.

Adult↗
PubMed2000

Anterior interosseous nerve palsy associated with Galeazzi fracture.

Galeazzi fracture is more common in adults than in children. Associated neurologic deficits are rare and easily missed at the first clinical examination. The authors describe a case of anterior interosseous nerve palsy after closed Galeazzi fracture. Conservative treatment resulted in complete return of normal nerve function, suggesting that this is a neurapraxia type of injury.

Child↗