Causality Between the Amplitude and Frequency of Cardiac Oscillations

Using an information-theoretic approach, causality between the systolic amplitude in blood pressure and the frequency of the heart beat was analyzed. Blood pressure and ECG were noninvasively recorded in young, healthy subjects. Three successive measurements were performed: during spontaneous breathing and during paced respiration—at frequencies both higher and lower than that of spontaneous respiration. We demonstrate that the amplitude and frequency of the cardiac rhythm are synchronized for most of the time. The synchronization is stronger during paced respiration at a frequency lower than that of spontaneous breathing. Episodes where the cardiac frequency was driven by the systolic pressure were also detected during slow, paced respiration.     

Inhibitory motor control in children with attention-deficit/hyperactivity disorder: event-related potentials in the stop-signal paradigm.

BACKGROUND: The aim of the study was to investigate the inhibitory control of an ongoing motor response and to identify underlying neural deficiencies, manifested in event-related potentials, that cause poorer inhibitory performance in children with attention-deficit/hyperactivity disorder. METHODS: A stop-signal paradigm with a primary visual task and auditory stop signal was used to compare performance in 13 children with attention-deficit/hyperactivity disorder and 13 control children, while event-related potentials were recorded simultaneously. RESULTS: Children with attention-deficit/hyperactivity disorder showed poorer inhibitory performance through a slower inhibitory process. Inhibitory processing of auditory stop signals was marked by a frontal N2 component that was reduced in the attention-deficit/hyperactivity disorder group relative to controls. A central positive component (P3) was associated with the success of inhibiting a response, but there were no group differences in its amplitude or latency. CONCLUSIONS: Findings support the hypothesis of deficient inhibitory control in children with attention-deficit/hyperactivity disorder. Slower inhibitory processing appears to be due to a specific neural deficiency that manifests in the processing of the stop signal as attenuated negativity in the N2 latency range.     

Sensitivity of human pulmonary mast cells obtained by bronchoalveolar lavage to immunological and nonimmunological histamine releasers

We have studied the sensitivity of human pulmonary mast cells to some immunological and nonimmunological histamine releasers. The pulmonary mast cells were obtained by bronchoalveolar lavage (BAL) of nonasthmatic patients. Mast cells constituted about 1% of total cell population and were morphologically intact. These cells were highly sensitive to the challenge with anti-human IgE. They responded to calcium ionophore A23187, polymyxin B and concanavalin A, however the magnitude of histamine release was low. BAL mast cells were unresponsive to the compound 48/80.     

A rare case of nasopharyngeal angiofibroma in an elderly female

Nasopharyngeal angiofibromas occur predominantly in males in their puberty and adolescence; the incidence in other age groups and in women is exceptional. This report describes a case of a 57-year-old woman with nasopharyngeal angiofibroma presenting typical radiological findings in computed tomography, MR imaging and angiography. The tumour was successfully removed and histopathological examination confirmed the diagnosis. In 6 years follow-up the patient is free of symptoms.     

Memory for object and object-location after lesions to the ventromedial prefrontal cortex in humans

The aim of the present study was to investigate the effect of small unilateral lesions to the ventromedial portion of the prefrontal cortex on two memory functions: memory for objects and memory for object locations. Patients, who had undergone surgery of the anterior communicating artery aneurysm, and normal control subjects, participated in the study. The patients were subdivided into two groups: with and without unilateral resection of the gyrus rectus. Subjects were presented with two memory tests, that required remembering either simultaneously presented visual stimuli (object memory test; OMT) or locations of the stimuli (location memory test; LMT). In the OMT, patients with resection of the gyrus rectus were impaired in comparison to patients without resection and normal control subjects. In the LMT, the three groups did not differ from each other. Our results suggest that the ventromedial prefrontal cortex is specifically involved in memory for objects.     

Substituting imputation of HLA antigens for high-resolution HLA typing: Evaluation of a multiethnic population and implications for clinical decision making in transplantation

Molecular mismatch analysis for assessment of histocompatibility in transplantation requires high-resolution HLA typing. Algorithms to “guesstimate” high-resolution from low-resolution typing exist, but their accuracy remains unknown. We converted high-resolution, sequence-based, HLA typing of 310 subjects from an ethnically heterogeneous population to low-resolution equivalents and tested the ability of the NMDP HaploStats and HLA Matchmaker programs to impute/reproduce the measured high-resolution HLA type, using the more common “winner-takes-all” approach. Only 35.6% of the HaploStats imputed HLA-A, -B, -C, -DRB1, and -DQB1 haplotypes had no mistakes, and the accuracy was significantly lower for non-Caucasians (29.1%) compared to Caucasians (45.2%) (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.3-0.8; P = .004). HLA Matchmaker was not able to provide high-resolution haplotypes for 45.2% of Caucasian subjects and 63.5% of non-Caucasian subjects (P = .002). Of those with an imputed result, only 10.3% of Caucasians and 4.8% of non-Caucasians had accurate 10-allele high-resolution output. Eplet analysis revealed additional, inaccurate eplets in 37% of individuals, with 22.5% showing at least 2 additional, inaccurate eplets; incorrect eplets were more common among non-Caucasians (OR, 1.8; 95% CI, 1.1-2.9; P = .018). Given this high error rate, caution should be taken before using imputation tools for clinical or research purposes, especially for non-Caucasian individuals.     

Effects of whole body hyperthermia (41.8 degrees C) on the frequency of tumor cells in the peripheral blood of patients with advanced malignancies.

PURPOSE: Combining heat with antineoplastic drugs has produced evidence of antitumor synergism. An increasing number of trials are investigating whole body hyperthermia (WBH) in combination with chemotherapy in patients with advanced malignancies. Here we investigated whether the hyperdynamic state of the circulation as a consequence of WBH may stimulate dissemination of malignant cells. EXPERIMENTAL DESIGN: WBH in combination with chemotherapy was administered by a radiant heat device to 20 consecutive patients with advanced epithelial malignancies. One WBH session lasted for approximately 4 h (90 min heating time, 60 min plateau at 41.8 degrees C, and 60-80 min cooling). Peripheral blood was drawn before WBH treatment (baseline), at the end of the plateau (1 h), and 24 h and 48 h thereafter. After removal of leukocytes using anti-CD45 magnetic beads, circulating tumor cells were detected immunocytochemically using the monoclonal antibody A45-B/B3, which binds to a common epitope present on various cytokeratins. RESULTS: The method used to detect tumor cells in the peripheral blood proved to be specific and very sensitive (detection limit 1 tumor cell per 1.7 x 10(5) peripheral blood mononuclear cell). Before WBH, 6 of 20 patients had cyto-keratin-positive cells in their blood. A treatment-induced increase in the number of circulating tumor cells became statistically significant at 24 h after WBH (P = 0.043) and was detected in a total of 9 patients, 5 of whom had no detectable malignant cells at baseline. There was no evidence of a correlation between an increase in the number of circulating tumor cells and increased metastasis frequency. CONCLUSIONS: Our findings suggest that WBH might induce a temporary release of tumor cells into the circulation, but this spread appears to be clinically not significant in patients with advanced malignancies.     

P21WAF1, P27KIP1, TP53 and C-MYC analysis in 204 ovarian carcinomas treated with platinum-based regimens.

BACKGROUND: The prognostic and predictive value of cell cycle regulatory proteins in ovarian cancer has not been established. We evaluated the clinical and biological significance of P21(WAF1), P27(KIP1), C-MYC, TP53 and Ki67 expressions in ovarian cancer patients. MATERIALS AND METHODS: Immunohistochemical analysis was performed on 204 ovarian carcinomas of International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IV treated with platinum-based chemotherapy. Multivariate analysis with Cox and logistic regression models was performed in the whole group, and in the TP53-negative and TP53-positive subgroups. RESULTS: High P21(WAF1) labeling index (LI) was an independent positive predictor of platinum-sensitive response (P = 0.02). Overall survival was positively influenced by P21(WAF1) LI (P = 0.02) or by P21(WAF1) plus P27(KIP1) LI (P = 0.004) in the TP53-negative group only. Ki67 LI showed borderline association with disease-free survival (P = 0.05). Growth fraction was negatively associated with P21(WAF1) and P27(KIP1) indices in the TP53-negative group (P = 0.023 and 0.008, respectively), and these associations were borderline or lost in the TP53-positive group. Endometrioid and clear cell carcinomas differed from other carcinomas by having a low incidence of TP53 accumulation, a high incidence of C-MYC overexpression (70%) and a low median Ki67 LI (all with P <0.001). CONCLUSIONS: We have shown an independent predictive value of P21(WAF1) LI in ovarian carcinoma patients. The prognostic value of P21(WAF1) and P21(WAF1) plus P27(KIP1) LI was determined by TP53 status. A high frequency of C-MYC overexpression in endometrioid and clear cell carcinomas may suggest its role in the development of these tumor types.