The composite N1 component to gaps in noise.

OBJECTIVE: To indicate whether the double peaked N(1) to gaps in continuous white noise is a composite of onset and offset responses to transients or whether it reflects higher processing such as change or mismatch detection and to assess the role of attention in this process. METHODS: Evoked potentials were recorded to two binaural stimulus types: (1) gaps of different durations randomly distributed in continuous white noise; and (2) click pairs at intervals identical to those between gap onsets and offsets in the continuous noise stimulus. Potentials to these stimuli were recorded while subjects read a text and while detecting gaps in noise or click pairs. RESULTS: Potentials were detected to all click pairs and to gaps of 5 ms or longer, corresponding to the subjects' psychoacoustic gap detection threshold. With long gap durations of 200-800 ms, distinct potentials to gap onset and gap offset were observed. The waveforms to all click pairs and to offsets of long gaps were similar and single-peaked, while potentials to gaps of 10 ms and longer, and potentials to onsets of long gaps were double-peaked, consisting of two N(1) negativities, 60 ms apart, irrespective of gap duration. The first (N(1a)), was more frontal in its distribution and similar to that of clicks. The second (N(1b)) peak's distribution was more central/temporal and its source locations and time course of activity were distinct. No effects of attention on any of the varieties and constituents of N(1) were observed. CONCLUSIONS: Comparing potentials to gap onsets, to click pairs and to gap offsets, suggests that potentials to gap onsets involve not only sound onset/offset responses (N(1), N(1a)) but also the subsequent pre-attentive perception of the cessation of an ongoing sound (N(1b)). We propose that N(1b) is distinct from change or mismatch detection and is associated with termination of an ongoing continuous stimulus. We propose to call it the N(egation)-process. SIGNIFICANCE: A constituent of the N(1) complex is shown to be associated with the pre-attentive perception of termination of an ongoing stimulus and to have distinct scalp distribution and intracranial sources.     

A comparative study of measurement of arterial blood pressure using HEM-802F and arterial cannulation

Finger arterial blood pressures determined by a newly developed sphygmomanometer, HEM-802F, were compared with arterial pressure obtained from direct measurement of the radial artery. An excellent correlation was found between the two methods (systolic: r = 0.93, diastolic: r = 0.91), although there was a large variability among individual subjects. The range of differences between them are from +32 to –13mmHg for systolic and +15 to –25mmHg for diastolic blood pressure measurement. HEM-802F underestimated systolic pressure (–4.0mmHg) and overestimated diastolic pressure (+6.7mmHg), compared with intra-arterial readings.The HEM-802F was useful for the non-invasive arterial pressure monitoring during general anesthesia.(Shigemi K, Takahashi H, Hashimoto S et al.: A comparative study of measurement of arterial blood pressure using HEM-802F and arterial cannulation. J Anesth 4: 91–93, 1990)     

Clinical results of super high-dose chemotherapy with peripheral blood stem cell transplantation for patients with advanced germ cell tumor

We examined the clinical results of super high-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) in 14 patients with poor-risk advanced germ cell tumors. The mean number of nadir white blood cells was 205 +/- 126/microliter; the mean period of number of white blood cells fewer than 1,000/microliter was at 8-10 days (mean +/- SD; 9.2 +/- 0.92). The nadir number of blood platelet cells was 1.7 +/- 0.70 x 10(4)/microliter; the mean period of number of platelet cells fewer than 5 x 10(4)/microliter was at 12.6 +/- 2.17 days. Of 10 patients treated with super high-dose chemotherapy with PBSCT as induction therapy, 8 patients (80%) showed that the serum tumor marker returned within the normal range after super high-dose chemotherapy. Of 8 patients, 7 underwent resection of the residual tumor. Surgical or pathological CR was obtained in 5 of these 7 patients, 4 patients of whom were alive with no evidence of disease 29 to 49 months after initial consultation: the other patient died with recurrence 20 months after initial visit. On the other hand, super high-dose chemotherapy with PBSCT was performed for one patient as consolidation, and for 3 patients with recurrence. Of these 4 patients, one died from disease 6 months after detection of recurrence. The other 3 patients were alive with no evidence of disease at 7-37 months after initial visit. The 1- and 3-year disease-free survival rates were 88% and 72%, respectively. In conclusion, super high-dose chemotherapy with PBSCT can be done safely and could be useful for patients with poor-risk germ cell tumor.     

Severe exacerbation of hepatitis after short-term corticosteroid therapy in a patients with "latent" chronic hepatitis B

We present a case of severe exacerbation of hepatitis after short-term corticosteroid therapy for chronic inflammatory demyelinating polyneuropathy (CIPD) with "latent" chronic hepatitis B showing no HBV-related antigens and antibodies. After corticosteroid pulse therapy for CIPD, the patient had severe exacerbation of hepatitis twice. Although she did not show any hepatitis B virus (HBV)-related antigens or antibodies, sequences of HBV were detected in serum and liver by a nested polymerase chain reaction. A sequence analysis of HBV at the second exacerbation showed that the G-to-A point mutation at nucleotide 1896 that converted codon 28 from tryptophan (TGG) to a stop codon (TAG) in the precore region resulted in amino acid change, which has been frequently observed in fulminant hepatitis and severe hepatitis in Japan.     

Severe exacerbation of hepatitis after short‐term corticosteroid therapy in a patient with “latent” chronic hepatitis B

Abstract: We present a case of severe exacerbation of hepatitis after short‐term corticosteroid therapy for chronic inflammatory demyelinating polyneuropathy (CIPD) with “latent” chronic hepatitis B showing no HBV‐related antigens and antibodies. After corticosteroid pulse therapy for CIPD, the patient had severe exacerbation of hepatitis twice. Although she did not show any hepatitis B virus (HBV)‐related antigens or antibodies, sequences of HBV were detected in serum and liver by a nested polymerase chain reaction. A sequence analysis of HBV at the second exacerbation showed that the G‐to‐A point mutation at nucleotide 1896 that converted codon 28 from tryptophan (TGG) to a stop codon (TAG) in the precore region resulted in amino acid change, which has been frequently observed in fulminant hepatitis and severe hepatitis in Japan.     

Impact of a Rapid-Access Ambulatory Psychiatry Encounter on Subsequent Emergency Department Utilization

The authors sought to determine whether providing a rapid-access ambulatory psychiatry encounter correlated with emergency department utilization during a 6-month follow-up period. Electronic medical records of patients who accessed ambulatory psychiatric care through an urgent care psychiatry clinic that offers treatment exclusively on a walk-in basis over a 1-year period (N?=?157) were reviewed retrospectively to track emergency department encounters with and without a psychiatric chief complaint in the 6 months before and after the initial psychiatry evaluation. Among patients who had not previously received ambulatory psychiatric care (N?=?88), emergency department utilization decreased from 0.68 visits per patient to 0.36, and this difference was statistically significant (p?= 0.0147). No statistically significant differences were found between the average number of emergency department encounters in the 6 months before and after the rapid-access ambulatory psychiatry encounter, regardless of chief complaint, when all patients were included in the analysis. Providing a rapid-access ambulatory psychiatry encounter may reduce subsequent emergency department utilization among patients who have not previously received ambulatory psychiatric care.