Online time-differential perturbed angular correlation study with an O beam - Residence sites of oxygen atoms in highly oriented pyrolytic graphite

The online time-differential perturbed angular correlation (TDPAC) method was applied to a study of the physical states of a probe ¹⁹F, the β⁻ decay product of ¹⁹O (t_1/2 = 26.9 s), implanted in highly oriented pyrolytic graphite. The observed magnitude of the electric field gradient at the probe nucleus, ∣V_zz∣ = 2.91(17) × 10²² V m⁻², suggests that the incident ¹⁹O atoms are stabilized at an interlayer position with point group C_3v. Exhibiting observed TDPAC spectra having a clear sample-to-detector configuration dependence, we demonstrate the applicability of the present online method with a short-lived radioactive ¹⁹O beam.     

Small polypoid lesions of the gallbladder: differential diagnosis and surgical indications by helical computed tomography

We report the case of a 16-year-old girl who experienced sudden cardiac arrest from ventricular fibrillation, complicating an arrhythmogenic right ventricular dysplasia, a rare heart muscle disorder, occurring typically in young adults, characterized by a fibrofatty replacement of the right ventricular myocardium. Symptomatic ventricular arrhythmias are frequent, and sudden death has been reported. In our case, diagnosis of arrhythmogenic dysplasia was based on the association of one major criterion and two minor criteria as suggested by the relevant task force. In contrast with most other reports, the chest ECG did not display the typical features. An automatic transvenous pectoral cardioverter-defibrillator was implanted. The authors emphasise that juvenile forms are more exposed to ventricular fibrillation and sudden cardiac death, and consequently require the early detection of the disease. Family cases have been described and the occurrence in one individual must lead to investigations in the relatives.     

Serological survey of antibody to Neospora caninum in Japanese dogs

Prevalence of antibody to Neospora caninum (NC) in Japanese dogs were examined. The antibody was positive in 15 of 48 dogs (31.3%) reared in the dairy farms that had case of the abortions due to NC infection or had the cattle seropositive to NC, whereas the prevalence was 7.1% (14 of 198 dogs) among the dogs kept in urban areas. In one dog breeder, all 17 Shetland sheepdogs older than 7 months were seropositive, and one pup was diagnosed as neosporosis 2 months before the first serological examination. The antibody titers of the dogs kept at this breeder were almost unchanged for 1.5 years. Serological evidence of the dogs in the dairy farms and urban areas indicates the transmission of NC between dogs and cattle. Also serological results of the dogs in one breeder may suggest the potential horizontal transmission among dogs.     

Reoperation for recurrent coronary artery disease: results of 200 consecutive cases

OBJECTIVE: To quantify first-pass enhancement of cervix carcinoma using fast dynamic MRI. To assess the accuracy of dynamic contrast-enhanced colour-coded MRI for determining tumour invasion into surrounding pelvic tissues. METHODS: Gadolinium enhanced dynamic MRI at one image every 2 s was performed in 47 patients with cervical carcinoma and five controls. First-pass contrast enhancement of cervix carcinoma and surrounding pelvic tissues was quantified. Automated colour-coded images were constructed using the dynamic parameters slope, amplitude and timing of enhancement. Of 47 patients, 28 underwent surgery and colour coded images were correlated with histological findings. RESULTS: First-pass contrast enhancement imaging of cervix carcinoma required a temporal resolution of dynamic MRI of one image every 3-4 s. Cervix carcinoma first-pass was more rapid and intense than that of other pelvic tissues (P<0.001) with the exception of normal myometrium (P>0.05). Binary colour coding, however, was not reliable for tumour delineation or for accurate assessment of tumour invasion into the parametria or the bladder wall. Overestimation of the extent of tumour invasion occurred in 15, 16 and nine out of 28 patients, respectively, using amplitude, slope and timing of enhancement as parameters. CONCLUSION: Dynamic contrast-enhanced colour-coded MRI of cervix carcinoma has limited value for assessing the extent of tumour spread and tumour staging.     

Efficacy of microwave coagulation therapy (MCT) in patients with liver tumors

We evaluated the efficacy of microwave coagulation therapy (MCT) in 84 patients with hepatocellular carcinomas (HCC) and 40 with metastatic liver tumors (MLT). The response rates calculated with diagnostic imaging were 92% in HCC and 80% in MLT. The regional recurrence rates were relatively higher in patients with MLT (33%) than in HCC (14%). The average surgical margin in operative MCT group was 11 mm. The cumulative survival rates at three and five years were 63% and 38% in HCC and 43% and 33% in MLT, respectively. The complications were similarly encountered in HCC and MLT (12% versus 13%). When these observations are taken together, MCT is a radical and safe locoregional therapy which can keep an adequate surgical margin and assure long survival.     

Exchangeability of actin in cardiac myocytes and fibroblasts as determined by fluorescence photobleaching recovery

OBJECTIVE: To assess whether hypertension is a risk factor for hysterectomy performed for benign diseases. METHODS: Self-report questionnaires were collected from 77% of 2301 Danish women aged 30, 40, 50, or 60 years selected at random in 1982 for a prevalence study. Information about cardiovascular diseases, hypertension, use of medicine, weight and dieting history, life-styles, psychologic factors, gynecologic history (including history of hysterectomy), and social background were recorded. Weight, height, and blood pressure were measured. In an incidence study, the cohort was followed during 1982-1990 via central registers to assess the incidence of hysterectomy. Logistic and Cox regressions were used to analyze data. RESULTS: In the prevalence study, history of hypertension partly explained the relation between hysterectomy and cardiovascular diseases. In the incidence study, history of hypertension and use of diuretics were significant risk factors for hysterectomy. After confounder control, use of diuretics was explained by weight-related variables, and hypertension was a risk factor for hysterectomy in educated women (adjusted relative risk [RR] 2.88, 95% confidence interval [CI] 1.07, 7.76) and in women with weight fluctuations (adjusted RR 3.31, 95% CI 1.35, 8.14). Weight cycling and lack of education remained significant risk factors for hysterectomy in women with and without hypertension, respectively. CONCLUSION: History of hypertension, weight cycling, and lack of education are closely related risk factors for premenopausal hysterectomy. These three risk factors contribute to women undergoing hysterectomy having an increased risk for cardiovascular diseases. We proposed that hypertension might be a plausible biological cause of menorrhagia and an indication for hysterectomy.     

Autonomic nervous system dysfunction in elderly hypertensive patients with abnormal diurnal blood pressure variation: relation to silent cerebrovascular disease

To investigate the relationships among diurnal blood pressure (BP) variations and autonomic nervous system dysfunction, we assessed heart rate variability (HRV) using power spectral analysis of the 24-hour RR interval in 51 asymptomatic elderly hypertensive patients with various patterns of nocturnal BP fall. The extreme-dippers with marked nocturnal BP fall (n=16) had lower asleep low-frequency power (LF)/high-frequency power (HF) ratios (a relative index of sympathetic nervous system activity), while the nondippers without nocturnal BP fall (n=18) had lower awake LF/HF ratios and asleep/awake ratio for HF (an index of parasympathetic nervous activity), when compared with dippers with appropriate nocturnal BP fall (n=17). The incidence of multiple lacunar infarction detected by brain magnetic resonance imaging was 56% in the extreme-dippers and 38% in the nondippers, and both were markedly higher than that (6.3%) in the dippers (both P<.01). There was no significant relationship between the BP level and any HRV parameter for either the daytime or nighttime period. The asleep/awake ratio for systolic BP was significantly correlated with the asleep/awake ratio for HF (r= -.363, P<.01) and with the asleep/awake ratio for the LF/HF ratio (r=.540, P<.001), regardless of whether multiple lacunar infarction was present. In conclusion, the autonomic nervous system activity is not related to high BP level per se, rather its diurnal variation is more important as a determinant of the diurnal BP patterns, regardless of the presence or absence of cerebrovascular disease.     

Deuterium trapping by irradiation damage in tungsten induced by different displacement processes

The deuterium trapping behaviors in tungsten damaged by light ions with lower energy (10 keV C⁺ and 3 keV He⁺) or a heavy ion with higher energy (2.8 MeV Fe²⁺) were compared by means of TDS to understand the effects of cascade collisions on deuterium retention in tungsten. By light ion irradiation, most of deuterium was trapped by vacancies, whose retention was almost saturated at the damage level of 0.2 dpa. For the heavy ion irradiation, the deuterium trapping by voids was found, indicating that cascade collisions by the heavy ion irradiation would create the voids in tungsten. Most of deuterium trapped by the voids was desorbed in higher temperature region compared to that trapped by vacancies. It was also found that deuterium could accumulate in the voids, resulting in the formation of blisters in tungsten.