A murine plasmacytoma with a variant (15;16)(D2/3;B1) translocation that involves the c-myc and lambda light chain gene-carrying chromosomes

A murine plasmacytoma (MPC) with a reciprocal translocation between chromosomes 15 and 16 with breakpoints in 15D2/3 and 16B1 is reported. The breakpoint on chromosome 15 is identical to the breakpoint in the MPC-associated typical (12;15) and kappa variant (6;15) translocation. Therefore it probably involves the c-myc gene as well. Unlike the Burkitt lymphoma (BL) system, a lambda/myc variant translocation has not been described in the MPC system. Chromosome 16 is known to carry the lambda gene. Therefore, the 15;16 translocation probably represents the "missing" lambda/myc variant in MPC, suggesting that the lambda gene is localized at 16B1.     

Age-specific cerebral perfusion in 4- to 15-year-old children: a high-resolution brain SPET study using 99mTc-ECD

This study addresses the question of whether the normal range for distribution of local cerebral blood flow (lCBF) in adults can be transferred to the 4- to 15-year-old age group. Twenty-three children (age: 4–15 years; mean 11±3 years, group I) and 10 adults (age: 27–56 years; mean 45±10 years, group II) without evidence of cerebrovascular disease or other brain diseases underwent technetium-99m ethyl cysteinate dimer single-photon emission tomography. Counts in cortical and subcortical regions of interest (ROIs) were related to those in cerebellar ROIs (= 100%). Relative cortical activity in group I exceeded that in group II, particularly in left parietal (107.6%±9.8% vs 84.1%±12.4%), left frontal (97.7%±6.7% vs 79.4%±8.9%) and left temporal areas (99.7%±7.4% vs 84.9%±10.1%) and in the cingulate cortex (112.1%±9.1% vs 95.9%±10.1%, P<0.05). Cerebral activity uptake per injected dose was inversely correlated with age in 19 children of group I (r = –0.77, P<0.001). In group I, there was also an inverse correlation between age and the relative local count density in the parietal (r = –0.42 to –0.57), frontal (r = –0.48), temporal (r = –0.42 to –0.58) and occipital cortex (r = –0.44). In these cortical regions relative counts differed when subgroups of children aged 4–10 and 11–15 years were analysed. It is concluded that there are systematic differences between 4- to 15-year-old children and adults with regard to normal lCBF. Diagnostic use of perfusion agents has to consider age-adjusted normal flow maps; normal ranges should be determined separately for the age groups 4–10 and 11–15 years. Received 23 March and in revised form 11 July 1997     

Spectrum of coronary arterial spasm. Clinical, angiographic and myocardial metabolic experience in 29 cases

A relationship of coronary arterial spasm to variant angina pectoris, subendocardial ischemia, major ventricular arrhythmias and myocardial infarction has been demonstrated. In 29 patients, spasm was angiographically observed in normal-appearing coronary arteries (7 patients) as well as superimposed on various degrees of coronary atherosclerotic obstruction (22 patients). All patients experienced an atypical anginal syndrome; 16 patients also experienced typical exertional angina. Coronary spasm appeared to be a major contributory factor in eight occurrences of myocardial infarction and in 11 incidents of ventricular tachycardia, ventricular fibrillation and heart block.

Coronary spasm in the 29 cases was distributed in the following fashion: left main trunk, 6 cases; right main trunk, 12 cases; proximal left anterior descending artery, 13 cases; proximal circumflex artery, 1 case; distal left anterior descending artery, 1 case; and distal circumflex artery, 2 cases. In 5 cases coronary spasm was noted at multiple sites.

In contrast to findings in patients manifesting only typical exertional angina, the hemodynamic findings during spasm were those of a hypodynamic state. Left ventricular systolic pressure decreased from 138.9 ± 6.0 (mean ± standard error of the mean) to 113.2 ± 6.2 mm Hg; left ventricular end-diastolic pressure did not change significantly. Myocardial lactate extraction during spasm was invariably markedly reduced: −53.19 percent ± 15.44 (P < 0.001). However, the effect of coronary sinus pacing on myocardial lactate extraction was not significantly abnormal: +15.74 percent ± 6.66.

The respective roles of medical and surgical intervention are uncertain. Only 3 patients had a completely satisfactory pharmacologic response to nitrates alone or in combination with propranolol, and the condition of 5 others was partially improved; the remaining 21 patients were judged intractable to medical management. Coronary bypass surgery was performed as the ultimate recourse in 18 patients. However, short-term results reveal that only nine (50 percent) showed improvement, four (22 percent) had myocardial infarction during or after surgery and four (22 percent) died.

These studies confirm that coronary arterial spasm is a definite pathogenetic factor in a variety of acute myocardial ischemic syndromes. The incidence and full clinical significance of this functional disorder remain to be determined.     

Regional variation in capillary permeability of ventricular myocardium

The transcapillary exchange of horseradish peroxidase (HRP) has been investigated in the principal layers of rat ventricular myocardium. Cardiac arrest was induced in rats by the intravenous (iv) administration of KCl at intervals of 4–180 sec after the iv injection of HRP. The coronary arteries of non-working hearts were perfused with peroxidase for 90–300 sec. Sections from both ventricles were processed for light and electron cytochemistry, and thin sections examined by electron microscopy. The capillaries in the subendocardial and intermediate regions of both ventricles exhibit greater permeability than the subepicardial capillaries, as manifested by the more rapid extravascular passage of HRP. This permeability gradient is detectable for at least 15 sec after iv injection of the tracer, and for as long as 5 minutes when the enzyme is perfused. The observations suggest that permeability differences in subendocardial and subepicardial capillaries have an ultrastructural basis and provide further evidence for the functional heterogeneity of ventricular myocardium.     

Vestibular evoked myogenic potentials and habituation to seasickness

Objective

Seasickness may impose severe limitations on the performance of ships’ crew. Cervical vestibular evoked myogenic potentials (cVEMP) assess the function of the saccule, the organ responsible for monitoring vertical linear acceleration, which has been found to be the most provocative motion stimulus in the evolution of motion sickness. We used the cVEMP test in a prospective evaluation of susceptibility and habituation to seasickness.

Methods

Forty-six naval recruits underwent the cVEMP test before exposure to sea conditions. After 6 months’ sailing experience, participants completed a questionnaire evaluating their initial and current seasickness severity. Based on their most recent experience, subjects were divided into three groups: non-vomiting non-habituating (NV-NH), vomiting (V), and non-vomiting habituating (NV-H).

Results

Statistically significant lower thresholds for cVEMP were found in subjects who habituated to sea conditions (NV-H), compared with those remaining severely susceptible (V) (77.0 dB HL vs. 84.9 dB HL; p < 0.01).

Conclusions

The ability to produce the cVEMP at lower thresholds represents a broader dynamic range, in which the reflex can respond to a wider array of stimuli amplitudes.

Significance

The present study demonstrates the potential of the cVEMP test for predicting future habituation to seasickness.     

Comparison of 16-slice MSCT and MRI in the assessment of squamous cell carcinoma of the oral cavity

The goal of this retrospective study was to assess the accuracy of 16-slice multislice CT (MSCT) and MRI in staging of patients with primary squamous cell carcinoma (SCC) of the oral cavity. Fifty-two patients with histologically proven primary SCC were examined with contrast enhanced MSCT and MRI at 1.5 T with a combined head and surface neck coil. Image modalities were evaluated in a blinded fashion by two radiologists and an oral-maxillofacial surgeon in consensus concerning tumour depiction, local tumour infiltration and cervical lymph node metastases. Results of the radiological assessment were correlated with the intraoperative and histopathological findings in all patients. 36 of 52 primary tumours (69.2%) were depicted by MSCT while 44 were localized by MRI (84.6%). Regarding muscle infiltration MRI versus MSCT had a sensitivity of 81.8% versus 72.7%, but a low specificity and an accuracy of 63.4% versus 61% and 67.3% versus 63.5%, respectively, were found. There was a trend towards a better detection of bony infiltration by MRI than MSCT with a sensitivity of 100% versus 71.4%, a specificity of 93.3% versus 95.5% and an accuracy 94.2% versus 92.3%, respectively. Detection of cervical lymph node involvement was similar for MRI and MSCT with a sensitivity of 84.2% and 78.9%, a specificity of 63.6% and 75.7% and an accuracy of 71.1% and 76.9%, respectively. For N-staging both methods failed to detect small metastasis. For T-staging MRI was superior to MSCT, because there was a tendency to underestimate the tumour size by MSCT more often (19.4% versus 6.8% by MRI). Therefore, pre-operative MRI is recommended as the basic imaging modality of choice for treatment planning of oral SCC. MSCT is a valid alternative imaging method especially in cases with low patient compliance.     

牛津单髁膝关节置换：长期结果

牛津膝置换是使用最广泛的膝关节单髁置换（UKR）。牛津膝在37年前开始应用,拥有一个全匹配的活动衬垫,因而磨损率非常低。牛津膝最主要的使用指征是膝关节前内侧骨关节炎,这种病人至少占所有需要行膝关节置换术患者的50％。由于这一系统的设计特点,传统UKR的反指征,如年龄、活动量、肥胖、髌股关节损害和软骨钙质沉着症等对于牛津膝均不是反指征。与全膝关节置换（TKR）相比,牛津膝提供更快的康复、更好的功能、更大的活动度和更好的术后满意度,发生并发症更少、程度更轻,病残率和死亡率更低。一个持续超过30年的研究显示在90％的病例中,牛津膝为患者终生提供了优或良的临床结果,且不需要翻修。在最近15年,牛津膝通过微创手术入路植入,涉及6000多例使用该入路牛津膝置换的9个研究报道显示,10年生存率约95％。在许多这样的研究中,医生们在拟行膝关节置换的患者中约50％使用了牛津单髁膝置换。     

Prevalence of the metabolic syndrome among patients receiving clozapine

OBJECTIVE: This study compared the prevalence of the metabolic syndrome among outpatients with schizophrenia and schizoaffective disorder receiving clozapine with a matched comparison group from the National Health and Nutrition Examination Survey. METHOD: Ninety-three outpatients and a matched group of 2,701 comparison subjects were compared according to National Cholesterol Education Program criteria. Outpatient data were obtained through physical assessments, laboratory testing, and reviews of medical records. RESULTS: The prevalence of the metabolic syndrome was significantly higher among clozapine patients (53.8%) than among the comparison group (20.7%). For clozapine patients, logistic regression analysis revealed significant associations with age, body mass index, and duration of clozapine treatment. Only age and body mass index were associated with the prevalence of metabolic syndrome in both groups. CONCLUSIONS: Patients receiving clozapine are at significantly increased risk for developing the metabolic syndrome. Psychiatrists and other providers should consider performing regular physical health monitoring to prevent long-term adverse health consequences.     

Double dissociation of dopamine genes and timing in humans

A number of lines of evidence implicate dopamine in timing [Rammsayer, T. H. Neuropharmacological approaches to human timing. In S. Grondin (Ed.), Psychology of time (pp. 295-320). Bingley, UK: Emerald, 2008; Meck, W. H. Neuropharmacology of timing and time perception. Brain Research, Cognitive Brain Research, 3, 227-242, 1996]. Two human genetic polymorphisms are known to modulate dopaminergic activity. DRD2/ANKK1-Taq1a is a D(2) receptor polymorphism associated with decreased D(2) density in the striatum [J?nsson, E. G., Nothen, M. M., Grunhage, F., Farde, L., Nakashima, Y., Propping, P., et al. Polymorphisms in the dopamine D(2) receptor gene and their relationships to striatal dopamine receptor density of healthy volunteers. Molecular Psychiatry, 4, 290-296, 1999]; COMT Val158Met is a functional polymorphism associated with increased activity of the COMT enzyme such that catabolism of synaptic dopamine is greater in pFC [Meyer-Lindenberg, A., Kohn, P. D., Kolachana, B., Kippenhan, S., McInerney-Leo, A., Nussbaum, R., et al. Midbrain dopamine and prefrontal function in humans: Interaction and modulation by COMT genotype. Nature Neuroscience, 8, 594-596, 2005]. To investigate the role of dopamine in timing, we genotyped 65 individuals for DRD2/ANKK1-Taq1a, COMT Val158Met, and a third polymorphism, BDNF Val66Met, a functional polymorphism affecting the expression of brain-derived neurotrophic factor [Egan, M. F., Kojima, M., Callicott, J. H., Goldberg, T. E., Kolachana, B. S., Bertolino, A., et al. The BDNF val66met polymorphism affects activity-dependent secretion of BDNF and human memory and hippocampal function. Cell, 112, 257-269, 2003]. Subjects were tested on a temporal discrimination task with sub- and supra-second intervals (500- and 2000-msec standards) as well as a spontaneous motor tempo task. We found a double dissociation for temporal discrimination: the DRD2/ANKK1-Taq1a polymorphism (A1+ allele) was associated with significantly greater variability for the 500-msec duration only, whereas the COMT Val158Met polymorphism (Val/Val homozygotes) was associated with significantly greater variability for the 2000-msec duration only. No differences were detected for the BDNF Vall66Met variant. Additionally, the DRD2/ANKK1-Taq1a polymorphism was associated with a significantly slower preferred motor tempo. These data provide a potential biological basis for the distinctions between sub- and supra-second timing and suggest that BG are integral for the former whereas pFC is implicated in the latter.     

Human Leukemia-Associated Anti-Nuclear Reactivity

A brilliant, coarsely granular nuclear antigen was detected by anti-complement immunofluorescence in the nuclei of acute myeloid leukemia myeloblasts. Designated as LANA (leukemia-associated nuclear antigen), the reactivity differs from that of the Epstein-Barr-virus-determined nuclear antigen (EBNA) in immunological specificity and morphological appearance, although it is visualized by the same method. Serum from acute myeloid leukemia patients gave positive reactions in 73% of the cases. In acute lymphatic leukemia, chronic myeloid leukemia, chronic lymphatic leukemia, and Burkitt's lymphoma the sera were positive in 35, 14, 19, and 24%, respectively. Two of five polycythemia and two of eleven myeloma sera were also positive. Among 61 healthy controls, 58 were negative, whereas three showed a diffuse nuclear staining with a different pattern. Among 24 carcinoma patients, 18 were negative, whereas six gave a nuclear staining with a different, diffuse pattern. Sera from 20 patients who had recovered from infectious mononucleosis were all negative. In addition to the blasts of acute myeloid leukemia, a similar reactivity was seen with two Epstein-Barr virus DNA and EBNA-negative African lymphoma biopsies and in a short-lived tissue culture line derived from one of them. LANA could be a fetal or tissue-specific antigen, a virally determined antigen, or a specific form of anti-nuclear reactivity.