Preliminary experience with beta-tricalcium phosphate for use in mastoid cavity obliteration after mastoidectomy.

OBJECTIVE: To examine the efficacy and safety of mastoid cavity obliteration using highly purified beta-tricalcium phosphate (beta-TCP) after mastoidectomy in middle ear surgery. PATIENTS: Thirteen patients with cholesteatoma invading the mastoid cavity or showing severe pathologic changes in the mastoid cavity. INTERVENTION: Twelve patients underwent mastoid obliteration with highly purified beta-TCP during the first- and/or second-stage operation of a 2-stage canal-up operation: 5 patients during the first and second stages, and 7 patients during the second stage only. One patient with cholesteatoma underwent mastoid obliteration with highly purified beta-TCP during a 1-stage canal-up operation. In total, beta-TCP was applied in 18 ear operations. MAIN OUTCOME MEASURES: All patients underwent multislice computed tomography (CT) before and after surgery to assess the condition of the middle ear. The amount of residual beta-TCP granules in the mastoid cavity was assessed using the following granular shadow grading scale: Grade 0, no granular shadow in the mastoid cavity; Grade 1, residual granular shadows in part of the mastoid cavity; and Grade 2, granular shadows in most of the mastoid cavity. To assess any harmful effect of beta-TCP implanted in the mastoid cavity, continuous postoperative discharge and delayed wound healing were recorded. In addition, the bone conduction threshold was assessed using pure-tone audiometry, and the patients were asked whether they experienced vertigo or dizziness during the postoperative follow-up. RESULTS: All the patients who underwent multislice CT less than 11.4 months after mastoid cavity obliteration with beta-TCP were Grade 2 on the granular shadow grading scale, whereas all those who underwent multislice CT more than 53.8 months after mastoid obliteration were Grade 0. No patient had continuous postoperative discharge, delayed wound healing, or extrusion of beta-TCP granules. No patient showed deterioration of the bone conduction threshold more than 10 dB after mastoid cavity obliteration with highly purified beta-TCP or complained of postoperative vertigo or dizziness. CONCLUSION: Highly purified beta-TCP may be safe and reliable for mastoid obliteration. Highly purified beta-TCP may also be useful in other surgical procedures, including posterior wall reconstruction of the external auditory canal and scutum plasty.     

Metabolism of the psychotomimetic tryptamine derivative 5-methoxy-N,N-diisopropyltryptamine in humans: identification and quantification of its urinary metabolites.

The urinary metabolites of 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT) in humans have been investigated by analyzing urine specimens from its users. For the unequivocal identification and accurate quantification of its major metabolites, careful analyses were conducted by gas chromatography/mass spectrometry, liquid chromatography/mass spectrometry, and liquid chromatography-tandem mass spectrometry, using authentic standards of each metabolite synthesized. Three major metabolic pathways were revealed as follows: 1) side chain degradation by O-demethylation to form 5-hydroxy-N,N-diisopropyltryptamine (5-OH-DIPT), which would be partly conjugated to its sulfate and glucuronide; 2) direct hydroxylation on position 6 of the aromatic ring of 5-MeO-DIPT, and/or methylation of the hydroxyl group on position 5 after hydroxylation on position 6 of the aromatic ring of 5-OH-DIPT, to produce 6-hydroxy-5-methoxy-N,N-diisopropyltryptamine (6-OH-5-MeO-DIPT), followed by conjugation to its sulfate and glucuronide; and 3) side chain degradation by N-deisopropylation, to the corresponding secondary amine 5-methoxy-N-isopropyltryptamine (5-MeO-NIPT). Of these metabolites, which retain structural characteristics of the parent drug, 5-OH-DIPT and 6-OH-5-MeO-DIPT were found to be more abundant than 5-MeO-NIPT. Although the parent drug 5-MeO-DIPT was detectable even 35 h after dosing, no trace of its N-oxide was detected in any of the specimens examined.     

Prediction of reflex sympathetic dystrophy in hemiplegia by evaluation of hand edema

OBJECTIVE: To determine the predictive value of measurements of hand edema for the development of reflex sympathetic dystrophy (RSD). DESIGN: Cohort study. SETTING: Departments of rehabilitation medicine in 3 general hospitals and 1 rehabilitation hospital in Japan. PARTICIPANTS: Thirty-four stroke patients. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Measurement of the circumference of the middle finger was used to evaluate hand edema. The degree of hand edema was expressed by the ratio of circumference of the middle finger (RCMF) in the affected side to that in the uninvolved extremity. RESULTS: Eight of 34 patients developed clinical RSD from 2 to 4 months after stroke. Hand edema showed a significant relationship to the development of RSD (ie, the patients who had an RCMF of above 1.06 at 4 weeks poststroke had significantly higher incidence of RSD than those with a lower RCMF; P=.0127). CONCLUSION: It is possible to predict the development of RSD in hemiplegia by measuring hand edema 4 weeks poststroke.     

The neurotic versus delusional subtype of taijin-kyofu-sho: their DSM diagnoses

The main purpose of the present study was to investigate the diagnostic concepts of taijin-kyofu-sho (TKS) and social phobia, by comparing the clinical diagnosis of TKS and the operational diagnosis of Diagnostic and Statistical Manual of Mental Disorders (3rd edition, revised; DSM-III-R). Three evaluators conducted semistructured interview for DSM-III-R (SCID axis I and II, the Japanese version) to 88 outpatients who visited Jikei University Daisan Hospital, Japan, over a period of 1 year, requesting Morita therapy. The patients were also independently diagnosed by three psychiatrists to identify TKS. A total of 65.8% of 38 cases of TKS were diagnosed as social phobia. Among the neurotic TKS cases, the percentage was high at 81.5%, while among the delusional TKS cases it was 27.3%. A total of 42.1% of the TKS cases were diagnosed as mood disorder; 60.5% of the TKS cases presented some axis II disorders, among which avoidant personality disorder was the most prevalent (31.6%). There was no significant difference between the neurotic and delusional subtypes of TKS, regarding comorbidity with axis I diagnoses. As for axis II diagnoses, delusional TKS patients had a higher rate of comorbidity with paranoid personality disorder, although they demonstrated very similar trends in comorbidity with all other personality disorders. In the diagnostic system of DSM-III-R, it is highly likely that the neurotic and delusional subtypes of TKS will be seen to correspond to different diagnostic categories.     

Diagnostic consideration of Morita shinkeishitsu and DSM-III-R

The purpose of the present study was to empirically and objectively clarify the diagnostic standing of Morita shinkeishitsu, the subject of Morita therapy, by comparing and contrasting it with the operational diagnosis of the Diagnostic and Statistical Manual of Mental Disorders (3rd edition, revised; DSM-III-R). Morita therapists' clinical diagnoses of 88 outpatients who requested Morita therapy were compared with the results of the independently conducted operational diagnoses (structured clinical interview for DSM (SCID) for DSM-III-R, the Japanese version). In view of the result of axis I diagnoses, Morita shinkeishitsu corresponds to anxiety disorders, although it is a complex that also embodies mood disorders, which were found in one-quarter of the cases, as well as personality disorders, which were found in half of the cases, especially cluster C (avoidant, obsessive-compulsive, and dependent personality disorders). Morita shinkeishitsu is almost equivalent to anxiety disorders (DSM-III-R, axis I), and is a complex, a part of which includes mood disorders and cluster C personality disorders.     

Cerebral hemodynamics and metabolism in patients with cerebral arteriovenous malformations: an evaluation using positron emission tomography scanning

OBJECT: The purpose of this study was to evaluate cerebral hemodynamic and metabolic features in patients with arteriovenous malformations (AVMs) by using positron emission tomography (PET) scanning. METHODS: Twenty-four patients with supratentorial cerebral AVMs participated in PET studies in which 15O inhalation steady-state methods were used. The authors recorded the values of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), the regional oxygen extraction fraction (rOEF), and the regional cerebral metabolic rate of O2 (rCMRO2) at three designated regions of interest (ROIs) in each patient. These ROIs included perilesional (ROI-p), ipsilateral remote (ROI-i), and contralateral symmetrical (ROI-c) brain regions. To identify the factors that exert a direct effect on the hemodynamics of brains affected by AVM, we also separated the lesions according to their size and flow type shown on angiograms, and grouped the patients according to the presence or absence of progressive neurological deficits. We then compared the PET parameters at different ROIs in individual patients and evaluated the mean values obtained for all 24 patients according to AVM flow type and size, and the presence or absence of progressive neurological deficits. CONCLUSIONS: Overall, mean rCBV and rOEF values were significantly higher in ROI-p than in ROI-c (p = 0.00046 and p = 0.015, respectively). No significant differences were seen between the ROI-i and ROI-c with respect to rCBF, rCBV, and rOEF. Mean rCMRO2 values were similar in the three ROIs; however, the mean rCBF was significantly lower in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.019), large AVMs (p = 0.017), and progressive neurological deficits (p = 0.021). Furthermore, the mean rOEF values were significantly higher in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.005), large AVMs (p = 0.019), and progressive neurological deficits (p = 0.017). The PET studies revealed hemodynamic impairment characterized by decreased rCBF and increased rOEF and rCBV values in the ROI-p of patients with large, high-flow AVMs regardless of whether they exhibited progressive neurological deficits.     

Biphasic effects of isoflurane on the cardiac action potential: an ionic basis for anesthetic-induced changes in cardiac electrophysiology

BACKGROUND: The mechanism underlying isoflurane modulation of cardiac electrophysiology is not well understood. In the present study, the authors investigated the effects of isoflurane on the cardiac action potential (AP) characteristics. The results were correlated to modulation of the L-type calcium (I(Ca,L)), the delayed-rectifier potassium (I(Kdr)), and the inward-rectifier potassium (I(Kir)) currents. METHODS: Single ventricular myocytes were enzymatically isolated from guinea pig hearts. The current clamp and whole cell voltage clamp configurations of the patch clamp technique were used to monitor the cardiac AP and ionic currents, respectively. A dynamic AP voltage protocol that mimicked changes in membrane potential during an AP was used to monitor the I(Ca,L), I(Kdr) and I(Kir). RESULTS: Isoflurane produced a concentration-dependent, biphasic effect on the AP duration (APD). At 0.6 mm (1.26 vol%), isoflurane significantly increased APD50 and APD90 by 50.0 +/- 7.6% and 48.9 +/- 7.2%, respectively (P < 0.05; n = 6). At 1.0 mm (2.09 vol%), isoflurane had no significant effect on APD (n = 6). In contrast, at 1.8 mm (3.77 vol%), isoflurane decreased APD50 and APD90 by 38.3 +/- 5.4% and 32.2 +/- 5.5%, respectively (P < 0.05; n = 7). The inhibitory effects of isoflurane on I(Kdr) chord conductance were greater than those on I(Ca,L) (P < 0.05; n = 6/group). Both I(Ca,L) inactivation and I(Kdr) activation kinetics were accelerated by isoflurane. Isoflurane had no significant effects on I(Kir) chord conductance (n = 6). CONCLUSION: At the lower anesthetic concentration, the prolongation of the APD may be the result of the dominant inhibitory effects of isoflurane on I(Kdr). At the higher concentration, the shortening of the APD may be caused by the inhibitory effects on I (Ca,L) combined with the isoflurane-induced acceleration of I(Ca,L) inactivation kinetics. Because I(Kdr) is significantly inhibited by isoflurane, I(Kir) appears to be the major repolarizing current, which is minimally affected by isoflurane.     

Thrombolytic therapy with tissue plasminogen activator for the treatment of nonstructural malfunction of bileaflet cardiac valve prostheses

This study was conducted to determine the effect of thrombolytic therapy with tissue plasminogen activator (t-PA) for nonstructural malfunction of bileaflet cardiac valve prostheses. Twenty-seven patients with bileaflet prosthetic valve malfunction diagnosed by a combination of cineradiography and transthoracic echocardiography were treated with the administration of intravenous t-PA. The treatment resulted in complete success in 55.6% (15 of 27), partial success in 22.2% (6 of 27), and no change in 22.2% (6 of 27). In the complete success and partial success groups, the condition of the patients in 85.7% (18 of 21) of the cases improved within 24 h after the administration of t-PA. Six cases in whom thrombolytic therapy was instituted more than 1 month (ranged from 1 to 38 months, mean 14.7 months) after the diagnosis of prosthetic valve malfunction showed significantly less effectiveness of thrombolytic therapy with t-PA. Only one patient (3.7%) had a major complication (thromboembolism) after t-PA treatment. The results suggest that thrombolytic therapy with t-PA in patients with nonstructural malfunction of bileaflet cardiac valve prostheses is effective with low incidence of complication when the treatment is instituted early after the diagnosis.     

Val-Tyr as a natural antihypertensive dipeptide can be absorbed into the human circulatory blood system

1. Intact absorption of the bioactive dipeptide Val-Tyr (VY), with in vivo antihypertensive ability in normotensive human subjects, was investigated. 2. As a result of a single oral administration of VY, the VY absorption curve occurred maximally over the second hour postprandially; a greater than 10-fold higher increment of VY following a dose of 12 mg was observed in the plasma at 2 h compared with the baseline concentration of VY at 0 h (1934 +/- 145 vs 159 +/- 11 fmol/mL plasma, respectively). 3. Plasma VY levels increased with dose administered (3, 6 and 12 mg), suggesting that exogenous VY could be absorbed intact into the human blood depending on the dose. The elimination half time (t1/2) of VY was estimated to be 3.1 h. The area under the curve for the 12 mg VY dose was 9185 +/- 688 fmol small middle doth/mL plasma.