Water-immersion wrinkling is due to vasoconstriction

The underlying mechanism of the water-immersion skin wrinkling test, which is used as a test of sympathetic nerve function, remains elusive. We investigated changes of blood circulation in the hand occurring with water-immersion wrinkling by measuring the velocity of ulnar and digital artery blood flow, and of digit skin blood flow, in healthy subjects before and during wrinkling. Wrinkling was accompanied by significant reduction in blood flow velocity in all vessels, with a maximum in digital vessels. Our data show that water-immersion wrinkling is a function of digit pulp vasoconstriction. This test of sympathetic function can now be quantified using parameters of blood flow velocity, enabling its more widespread and accurate use.     

Electrophysiological brainstem testing in the diagnosis of reversible brainstem ischemia

The aim of this study was to evaluate the sensitivity of multimodal electrophysiological brainstem testing in the diagnosis of clinically suspected reversible ischemic deficits of the brainstem compared with diffusion weighted MR imaging. We investigated 158 consecutive patients presenting with signs of acute brainstem dysfunction. Serial electrophysiological brainstem tests including masseter reflex, blink reflex, masseter inhibitory reflex, AEP, MEP, EOG and the oculoauricular phenomenon were applied. In 14 of the 158 patients neurological deficits resolved in less than 24 hours, which was suggestive of a transitory ischemic attack (TIA), 19 patients had brainstem signs for more than 24 hours but less than 1 week, suggestive of a reversible ischemic neurological deficit (RIND). Electrophysiological data indicated acute functional brainstem lesions in 54,5 % of patients with transient clinical brainstem impairment. Lesion detection rate was significantly higher when combining electrophysiological data and MRI (60,4 %) than using acute brainstem abnormalities in diffusion weighted MRI alone (39,4 %). We conclude that diffusion weighted MRI and electrophysiological brainstem testing are complimentary sensitive indicators of acute brainstem lesions in patients with reversible neurological deficits. Correct identification of brainstem ischemia influences the therapeutic regimen and may improve patient outcome. Received: 5 November 2001 Received in revised form: 28 January 2002 Accepted: 1 February 2002     

Susceptibility testing of Malassezia pachydermatis using the urea broth microdilution method

The in vitro susceptibility of 24 isolates of Malassezia pachydermatis to four antifungal drugs in combination with lysozyme was determined using a urea broth microdilution method. The antifungal activities of each drug alone against 24 isolates of M. pachydermatis were determined as the mean minimal inhibitory concentrations (MICs). MICs of bifonazole, itraconazole, amorolfine and terbinafine were 3.2 microg ml(-1), 1.6 microg ml(-1), 25 microg ml(-1) and 3.2 microg ml(-1), respectively. Lysozyme alone inhibited the growth of M. pachydermatis in a dose-dependent manner, although the lysozyme was unable to kill the cells of M. pachydermatis at the highest concentration of 20 microg ml(-1). Furthermore, the mean MICs of bifonazole, itraconazole, amorolfine and terbinafine in combination with lysozyme were the same as the results for each drug alone. Although the activity of antifungal drugs in combination with lysozyme is enhanced for other fungi. These results suggested that M. pachydermatis might not be affected by the host's natural defences.     

The role of the transvenous catheter electrophysiologic study in the evaluation and management of ventricular tachyarrhythmias associated with ischemic heart disease

The transvenous-catheter electrophysiologic (EP) study has occupied a central position in the investigation and management of patients with ischemic heart disease and a propensity to ventricular tachycardia (VT) or ventricular fibrillation (VF) for more than 25 years. However, demonstration of the superiority of the implantable cardioverter defibrillator (ICD) compared to other approaches to the management of VT/VF has resulted in a decrease in the frequency of use of the EP study in these patients. Nevertheless, the EP study remains a value-added procedure for many patients in this setting. These advantages include demonstration that the clinical arrhythmia is VT/VF when the diagnosis is uncertain, identification of those patients whose VT/VF is actually the result of a supraventricular tachyarrhythmia, identification of VT mechanisms readily amenable to catheter ablation, assessment of the response of a patient's VT to attempts at pace-termination, evaluation of candidacy for ablative VT therapy, prediction of the efficacy of approaches to prevention of VT/VF episodes, risk stratification of patients who have not yet experienced a sustained episode of VT/VF, and continued enhancement of our understanding of the mechanisms and therapeutics of VT/VF. The purpose of this review is to outline our present understanding of the techniques and indications for an EP study in patients with ischemic heart disease.     

A case of Kleine-Levin syndrome examined with SPECT and neuropsychological testing

A case of Kleine-Levin syndrome with typical periodic hypersomnia and bulimia was diagnosed. On examination with single photo emission tomography (SPECT) (CERETEC) during a relapse period and 2 weeks later there was marked cortical hypoperfusion of the frontal and temporal lobes, especially on the left side as well as in the right parietal lobe. Neuropsychological testing performed 1 week after a relapse showed a reduction in encoding to memory function of verbal learning indicating neocortical damage of the left fronto-temporal region. A follow-up 2 months later after the patient had spontaneously recovered showed only a slight left fronto-temporal disturbance. CT and MRI of the brain were normal although the MRI showed a large and asymmetric mamillary body. Neuropsychological testing 6 years after recovery showed pronounced reduction in short-time verbal and visual memory. Seven years after recovery SPECT demonstrated a normalized frontal perfusion but still a slight hypoperfusion in the left temporal lobe. Our results correlate to autopsy findings in two cases described previously.     

Interpretation and classification of microvolt T wave alternans tests

Measurement of microvolt-level T wave alternans (TWA) during routine exercise stress testing now is possible as a result of sophisticated noise reduction techniques and analytic methods that have become commercially available. Even though this technology is new, the available data suggest that microvolt TWA is a potent predictor of arrhythmia risk in diverse disease states. As this technology becomes more widely available, physicians will be called upon to interpret microvolt TWA tracings. This review seeks to establish uniform standards for the clinical interpretation of microvolt TWA tracings.     

Rh genotyping: avoiding false-negative and false-positive results among individuals of African ancestry

High homology, variant alleles, and silent alleles have made the development of completely reliable genotyping assays for the RHD and RHC alleles difficult. An RHD pseudogene (RHDPsi) possessing a 37-bp insertion within exon 4 is common among serologically RhD-negative individuals of African descent and generates false-positive results in previously reported RhD genotyping assays. Genotyping RhC is problematic due to exon 2 homology between RHD and RHC; however, an RHC-specific 109-bp insertion within intron 2 has been reported useful for genotyping. Primers flanking the exon 4 insertion point were used for detection of RHD and RHDPsi among a total of 231 serotyped individuals: 134 African American, 85 Caucasian, and 12 RhD serotype-negative/genotype-positive, D-sensitized women. Primers flanking the RHC-specific intron 2 insertion were used to genotype 282 serotyped individuals (128 African American, 154 Caucasian) and were compared to RHC genotyping using the exon 1 RhC-specific nt48 cytosine polymorphism. Complete correlation was observed between genotyping with the RHDPsi primer pair and serotyping among 219 individuals and 10/12 previous RHD false-positive genotyping results were resolved. RHDPsi was detected in 19% (n = 4/21) of RhD seronegative African Americans and 4.4% (n = 5/113) of RhD seropositive African Americans. When using the 109-bp intron 2 insertion for genotyping of RHC, a 23.9% (n = 11/46) false-negative rate was observed among African American RhCc serotyped heterozygotes. Utilization of the exon 1 nt48 cytosine for indirect genotyping of RHC yielded a 7.2% (n = 4/55) and 56.3% (n = 45/80) false-positive rate among Rhcc Caucasians and African Americans, respectively. We conclude that these additional reactions, though not sufficient alone, can be useful supplements to existing Rh genotyping assays.