Treatment of iatrogenic femoral arterial pseudoaneurysms: comparison of US-guided thrombin injection with compression repair

PURPOSE: To evaluate and compare the treatment of iatrogenic femoral arterial pseudoaneurysms by using ultrasonographically (US) guided direct thrombin injection with US-guided compression repair. MATERIALS AND METHODS: Twenty-six patients with iatrogenic femoral arterial pseudoaneurysms were treated with direct thrombin injection. With US guidance, a 22-gauge needle was placed into the pseudoaneurysm flow lumen and thrombin (mean volume, 0.35 mL; range, 0.10-0.60 mL) was injected with continuous color Doppler US guidance. Demographics, clinical variables, pseudoaneurysm characteristics, and results in these patients were compared with those in 281 consecutive patients who underwent US-guided compression repair. RESULTS: The success rate of thrombin injection was 96% (25 of 26 patients), which was significantly higher than that of compression, 74% (209 of 281 patients) (P =.013). Twenty of 26 (77%) patients required a single injection, and six (23%) required two injections. Mean thrombosis time for thrombin injection was 6 seconds, compared with 41.5 minutes for compression. For thrombin injection, there were no complications, foot pulses did not change and no patients required conscious sedation. Follow-up US at 24 hours showed no recurrent pseudoaneurysms. CONCLUSION: For the treatment of iatrogenic femoral arterial pseudoaneurysms, thrombin injection with US guidance appears to be superior to compression repair.     

Evaluation of pseudoenhancement of renal cysts during contrast-enhanced CT

OBJECTIVE: The purpose of our study was to evaluate renal cyst pseudoenhancement during helical CT in a phantom model and in patients. MATERIALS AND METHODS: Iodine baths containing water-filled spheres and cylinders were constructed to simulate cysts in enhancing renal parenchyma. Iodine concentration, cyst size and location, collimation, and peak kilovoltage were varied and cyst attenuation was measured. Data were analyzed with the mixed linear models and Mantel-Haenszel tests. Subsequently, a paired t test compared CT attenuation values before and after contrast material enhancement in 40 patients with 68 renal cysts (radiographic stability >3 months). RESULTS: The attenuation values of phantom cysts increased when placed in a contrast media bath (p = 0.001). The increase in attenuation values became more pronounced with increasing iodine concentrations, decreasing peak kilovoltage, and smaller sphere sizes. In patients, mean cyst attenuation increased 3.4 +/- 6.2 H after administration of contrast material (p = 0.00002). The attenuation did not increase more than 10 H in any of the 37 cysts larger than 2 cm found in patients. Eight (26%) of the 31 cysts smaller than 2 cm found in patients increased by at least 10 H. CONCLUSION: In a phantom model, at simulated physiologic levels of renal enhancement, cysts may pseudoenhance by more than 10 H. Similarly, in patients, cysts may also pseudoenhance; however, most pseudoenhancement does not exceed 10 H. In patients, pseudoenhancement of at least 10 H is more likely in cysts smaller than 2 cm.     

Stimulatory effects of methyltestosterone on pituitary gonadotropic cells and testes leydig cells of the three-spined stickleback, Gasterosteus aculeatus L., in winter

Male three-spined sticklebacks were kept for a month in short photoperiod at ca. 20 degrees in winter. During this period methyltestosterone (MT), dissolved in the water (35 micrograms/liter), stimulated the appearance of breeding colors and kidney hypertrophy, characters which were both absent in the controls. MT furthermore prevented the onset of spermatogenesis. The gonadotropic cells of the MT-treated fish contained significantly more dilated endoplasmic reticulum and less granules than those of the controls. The nuclei of the testes Leydig cells were enlarged after treatment with MT. These findings suggest the existence of a positive feedback of androgen on the gonadal-pituitary axis of the male stickleback in winter.     

Evaluation of poly(acrylic acid-co-ethylhexyl acrylate) films for mucoadhesive transbuccal drug delivery: factors affecting the force of mucoadhesion.

Based on the premise that similar surface properties between the adhesive and the substrate would yield a strong adhesive bond, copolymers of acrylic acid (AA) and 2-ethylhexyl acrylate (EHA), P(AA-co-EHA), were designed and synthesized for buccal mucoadhesion. A series of linear copolymers with varying feed ratios of the two monomers (AA and EHA) were synthesized through free radical copolymerization at 69+/-0.5 degrees C using azobis(isobutyronitrile) (AIBN) as initiator. The reactions were carried out in THF under nitrogen for 24 h. The glass transition temperatures, T(g), of the copolymers were determined using DSC. The adhesion studies were conducted to determine the effects of copolymer composition, contact time between the substrate and the adhesive, and crosshead speed on mucoadhesive performance of the copolymer films using a computer interfaced Instron material testing system. The glass transition temperature of the copolymers decreased with increasing EHA content. Wet glass surface as substrate was shown not to be a good substrate model for adhesion determination studies. The copolymer composed of 46:54 mol.% AA:EHA (an almost 1:1 ratio in the repeat units) yielded the highest mucoadhesive force in contact with porcine buccal mucosa which was significantly greater (P<0.05) than that of poly(acrylic acid) (PAA) (used as positive control). The mucoadhesive force for all copolymers studied was significantly (P<0.05) greater than that of the negative control (backing material without copolymer film) except for the EHA homopolymer. Crosshead speed increased mucoadhesive force linearly and had a more pronounced effect on the mucoadhesive performance than time of contact between the adhesive and the substrate.     

Human ovarian theca cells are a source of renin.

Human ovarian follicular fluid contains renin-like activity. In normal women, circulating levels of prorenin, the biosynthetic precursor of renin (EC 3.4.23.15), change in parallel with changes in progesterone during the menstrual cycle. Therefore, the ovary has been implicated as a source of plasma prorenin. In the present studies, we report the finding of high concentrations of prorenin in human ovarian follicular fluid (3000 ng.ml-1.hr-1 vs. 10-40 ng.ml-1.hr-1 in normal human plasma) obtained from follicles of women prepared for in vitro fertilization. The inactive renin-like enzyme was identified as prorenin by its activation characteristics, its molecular weight of 47,000, which is the same as that for recombinant prorenin, and its cross-reactivity with human renal renin antibodies. Culture of isolated human theca cells and isolated granulosa cells indicated that prorenin is secreted by theca cells but not by granulosa cells. Prorenin production by theca cells peaked during the first 10 days of culture and gradually decreased by 17 days. Active renin levels were 10% or less of the prorenin levels. Prorenin was barely detectable in medium from granulosa cells cultured for 24 days. Immunohistochemical staining of human ovaries (n = 5) with anti-human renin antibody demonstrated the presence of renin primarily in theca cells. These studies suggest that the theca cell is the source of the large quantities of prorenin in human ovarian follicular fluid.     

Neural correlates of olfactory processing in congenital blindness

Adaptive neuroplastic changes have been well documented in congenitally blind individuals for the processing of tactile and auditory information. By contrast, very few studies have investigated olfactory processing in the absence of vision. There is ample evidence that the olfactory system is highly plastic and that blind individuals rely more on their sense of smell than the sighted do. The olfactory system in the blind is therefore likely to be susceptible to cross-modal changes similar to those observed for the tactile and auditory modalities. To test this hypothesis, we used functional magnetic resonance imaging to measure changes in the blood-oxygenation level-dependent signal in congenitally blind and blindfolded sighted control subjects during a simple odor detection task. We found several group differences in task-related activations. Compared to sighted controls, congenitally blind subjects more strongly activated primary (right amygdala) and secondary (right orbitofrontal cortex and bilateral hippocampus) olfactory areas. In addition, widespread task-related activations were found throughout the whole extent of the occipital cortex in blind but not in sighted participants. The stronger recruitment of the occipital cortex during odor detection demonstrates a preferential access of olfactory stimuli to this area when vision is lacking from birth. This finding expands current knowledge about the supramodal function of the visually deprived occipital cortex in congenital blindness, linking it also to olfactory processing in addition to tactile and auditory processing.     

Hippocampal and caudate volume reductions in antipsychotic-naive first-episode schizophrenia

Background

Enlarged ventricles and reduced hippocampal volume are consistently found in patients with first-episode schizophrenia. Studies investigating brain structure in antipsychotic-naive patients have generally focused on the striatum. In this study, we examined whether ventricular enlargement and hippocampal and caudate volume reductions are morphological traits of antipsychotic-naive first-episode schizophrenia.

Methods

We obtained high-resolution 3-dimensional T₁-weighted magnetic resonance imaging scans for 38 antipsychotic-naive first-episode schizophrenia patients and 43 matched healthy controls by use of a 3-T scanner. We warped the brain images to each other by use of a high-dimensional intersubject registration algorithm. We performed voxel-wise group comparisons with permutation tests. We performed small volume correction for the hippocampus, caudate and ventricles by use of a false discovery rate correction (p < 0.05) to control for multiple comparisons. We derived and analyzed estimates of brain structure volumes. We grouped patients as those with (n = 9) or without (n = 29) any lifetime substance abuse to examine the possible effects of substance abuse.

Results

We found that hippocampal and caudate volumes were decreased in patients with first-episode schizophrenia. We found no ventricular enlargement, differences in global volume or significant associations between tissue volume and duration of untreated illness or psycho-pathology. The hippocampal volume reductions appeared to be influenced by a history of substance abuse. Exploratory analyses indicated reduced volume of the nucleus accumbens in patients with first-episode schizophrenia.

Limitations

This study was not a priori designed to test for differences between schizophrenia patients with or without lifetime substance abuse, and this subgroup was small.

Conclusion

Reductions in hippocampal and caudate volume may constitute morphological traits in antipsychotic-naive first-episode schizophrenia patients. However, the clinical implications of these findings are unclear. Moreover, past substance abuse may accentuate hippocampal volume reduction. Magnetic resonance imaging studies addressing the potential effects of substance abuse in antipsychotic-naive first-episode schizophrenia patients are warranted.     

Spinocerebellar ataxias: an update

PURPOSE OF REVIEW: Here we discuss recent advances regarding the molecular genetic basis of dominantly inherited ataxias. RECENT FINDINGS: Important recent observations include insights into the mechanisms by which expanded polyglutamine causes cerebellar degeneration; new findings regarding how noncoding expansions may cause disease; the discovery that conventional (i.e. nonrepeat) mutations underlie recently identified ataxias; and growing recognition that multiple biological pathways, when perturbed, can cause cerebellar degeneration. SUMMARY: The dominant ataxias, also known as spinocerebellar ataxias, continue to grow in number. Here we review the major categories of spinocerebellar ataxias: expanded polyglutamine ataxias; noncoding repeat ataxias; and ataxias caused by conventional mutations. After discussing features shared by these disorders, we present recent evidence supporting a toxic protein mechanism for the polyglutamine spinocerebellar ataxias and the recognition that both protein misfolding and perturbations in nuclear events represent key events in pathogenesis. Less is known about pathogenic mechanisms in spinocerebellar ataxias due to noncoding repeats, though a toxic RNA effect remains possible. Newly discovered, conventional mutations in spinocerebellar ataxias suggest a wide range of biological pathways can be disrupted to cause progressive ataxia. Finally, we discuss how new mechanistic insights can drive the push toward preventive treatment.     

Structural brain abnormalities in early onset first-episode psychosis

Summary Background. Brain morphometry in children and adolescents with first-episode psychosis offer a unique opportunity for pathogenetic investigations. Methods. We compared high-resolution 3D T1-weighted magnetic resonance images of the brain in 29 patients (schizophrenia, schizotypal disorder, delusional disorder or other non-organic psychosis), aged 10–18 to those of 29 matched controls, using optimized voxel-based morphometry. Results. Psychotic patients had frontal white matter abnormalities, but expected (regional) gray matter reductions were not observed. Post hoc analyses revealed that schizophrenia patients (n = 15) had significantly larger lateral ventricles as compared to controls. Duration and dose of antipsychotics correlated negatively with global gray matter volume in minimally medicated patients (n = 18). Conclusion. Findings of white matter changes and enlarged lateral ventricles already at illness onset in young schizophrenia spectrum patients, suggests aberrant neurodevelopmental processes in the pathogenesis of these disorders. Gray matter volume changes, however, appear not to be a key feature in early onset first-episode psychosis.