Middle cerebral artery flow velocity and cerebral oxygenation during abdominal aortic surgery

Cerebral perfusion was evaluated in twelve patients undergoing elective infra-renal abdominal aortic aneurysmectomy by transcranial Doppler ultrasonography-determined middle cerebral artery mean flow velocity, near-infrared spectroscopy-assessed cerebral oxygen saturation and systemic haemodynamic variables. The middle cerebral artery mean flow velocity and cerebral oxygen saturation decreased during cross-clamping of the aorta, and both increased upon declamping of the aorta with the oxygen saturation change lagging behind the change in the flow velocity. The changes in cerebral flow velocity and oxygen saturation paralleled the deviations in cardiac output and end-tidal carbon dioxide tension.     

Effects of isatin, an endogenous MAO inhibitor, on dopamine (DA) and acetylcholine (ACh) concentrations in rats

Isatin (indole-2,3-dione), an endogenous inhibitor of monoamine oxidase (MAO), has several physiological properties for stress and anxiety. We previously identified isatin in the brain of stroke-prone spontaneously hypertensive rats (SHRSP) using gas-chromatography mass spectrometry. This study elucidated the effects of isatin on the ACh and DA levels of brain tissues in rats. Furthermore, we evaluated the effect of isatin on DA levels in a rat model of Parkinson's disease induced by Japanese encephalitis virus. Striatal ACh and DA levels significantly increased at 2 hours after isatin (50-200 mg/kg, i.p.) administration. Perfused through a microdialysis probe, isatin (10(-6)-10(-4) M) also produced a significant and concentration-dependent increase in the ACh and DA concentrations in the perfusate from the rat striatum. Furthermore, urinary isatin concentrations in patients with Parkinson's disease tend to increase according to the severity of disease. Isatin (100 mg/kg, i.p.) significantly increased striatal DA levels in a rat model of Parkinson's disease. These results suggest that urinary isatin may become a diagnostic marker for the clinical severity of Parkinson's disease and that endogenous isatin, a new biological modulator, may play a role in the regulation of the brain levels of ACh by increasing the level of DA under stress.     

A mild transient decrease of peripheral red blood cell counts induced by a suprapharmacological dose of pegylated human megakaryocyte growth and development factor in rats.

Previous studies have shown that pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) at suprapharmacological dose induces a mild transient decrease of red blood cell counts according to thrombopoiesis in normal mice. To unravel the mechanism underlying this mild transient decrease of red blood cells, we have studied the effect of PEG-rHuMGDF on the circulating plasma and blood volume, and the serum biochemical parameters of anaemia and splenectomy. Also, we have performed histological studies of the bone marrow and the spleen of PEG-rHuMGDF-treated rats. PEG-rHuMGDF (300 microg kg(-1)]) or vehicle was subcutaneously administered to rats once a day for up to five days. From day 6 after the start of PEG-rHuMGDF administration, the platelet counts and plateletcrit levels were significantly increased, reaching peak values on day 10, and recovering to normal by day 20. The red blood cell counts and the haematocrit levels were significantly decreased on day 6 to 13. The decreases in red blood cell levels and haematocrit produced by PEG-rHuMGDF treatment were mild and had recovered by day 15. The plasma and blood volumes were significantly increased on day 10 in PEG-rHuMGDF-treated rats. No alteration of the serum biochemical parameters for anaemia, iron or total bilirubin, were observed on day 10. The histological examination on day 10 revealed a marked increase in megakaryocytes and a slight decrease in erythropoiesis in the bone marrow of rats that received PEG-rHuMGDF (300 microg kg(-1)). There was also a slight increase in splenic megakaryocytes and erythropoiesis. The decrease of red blood cells by PEG-rHuMGDF was not affected by splenectomy. These results suggest that the mild transient decrease of red blood cells induced by PEG-rHuMGDF treatment for up to five days is based mainly on the increases in the plasma and blood volume. These events are secondary changes due to the regulation of the excess production of megakaryocytes in the marrow and the peripheral platelets.     

Distribution of diaphragm blood flow during sevoflurane anaesthesia in dogs

Purpose

The purpose of this study was to determine the effect of increasing the concentrations of sévoflurane anaesthesia on the distribution of diaphragm blood flow (Qdi) in ten dogs during mechanical ventilation.

Methods

Animals were divided into two groups, sévoflurane (n = 6) and time control (n = 4) groups. Blood flow to the crural and the costal diaphragm (Qcru, Qcost) was determined by the hydrogen clearance technique at 0, 0.5, 1.0 and 1.5 minimum alveolar concentration (MAC) of sévoflurane after a 30 min period of steady-state conditions. Cardiac output (CO) and the mean arterial blood pressure (MBP) were also measured.

Results

Sevoflurane anaesthesia caused a reduction in CO (L · min^?1) from a control value of 1.51 ± 0.21 to 1.38 ±0.1 (0.5 MAC), 1.09 ± 0.15 (1.0 MAC) and 0.98 ± 0.12 (1.5 MAC) (Mean ± SD). Mean blood pressure, Qcru and Qcost also decreased with increasing depth of anaesthesia. In addition, the decrease of Qcru was greater than that of Qcost at all levels of MBP and CO. No change occurred in these variables in the lime control group.

Conclusion

Sevoflurane anaesthesia changes the distribution of Qdi with a greater reduction occurring in Qcru than in Qcost.     

Sensitivity and specificity of the fluorescent antibody technique for detection of infectious laryngotracheitis virus.

The specificity of a fluorescent conjugate to infectious laryngotracheitis virus was examined using chick trachea organ culture or tissue sections infected with other avian viruses (adenovirus, infectious bronchitis, poxvirus, reovirus, Newcastle disease virus, Marek's disease virus, avian encephalomyelitis and infectious bursal agent) or Mycoplasma gallisepticum. Confirmation of virus replication in these preparations was obtained by either 1) demonstration of virus titre increase or 2) demonstration of fluorescence when using the homologous conjugate. Once either of these criteria had been satisfied, negative results with the infectious laryngotracheitis conjugate were taken to indicate that the conjugate would not present false positive results in differentiated cells infected with these heterologous viruses. The spectrum of reactivity of the infectious laryngotracheitis conjugate was then examined on organ cultures infected with several infectious laryngotracheitis isolates from across Canada. Finally, the conjugate was applied to experimental and natural cases of infectious laryngotracheitis and its efficiency was compared to routine virus isolation methods.     

Spatial and temporal receptive-field analysis of the cats geniculocortical pathway

Receptive field (RF) properties of lateral geniculate (LGN) and cortical visual neurons were studied in cats using computer-controlled bar and edge stimuli. Responses to stationary presentations of an optimally oriented bright bar in an array of closely spaced RF positions provided detailed spatial and temporal information about RFs. Moving edge stimuli represent a more nearly normal viewing situation, and responses provide additional information for classifying RFs. Our results allow inferences about the nature of input connections to conical units. Responses of simple striate cells and X cells of LGN were similar to each other and quite different from those of complex and Y-LGN cells. Simple and X cells exhibited spatially segregated regions of excitation and inhibition and large shifts in response latency as a function of stimulus position. Both cell types showed spatially nonoverlapping regions of response (discharge zones) to moving bright and dark edges. These results provide correlational evidence that simple cells of striate cortex receive input predominantly from X-LGN cells. X-LGN cells respond to increases or decreases in local stimulus flux, depending on stimulus position, and via separate (from segregated RF areas) projections to the cortex determine contrast polarity of the cortical response. Complex cells, on the other hand, exhibited transient responses to both stimulus onset and removal. with a constant response latency across the entire RF. Results from the same test on Y-LGN cells were strikingly similar to those for complex cortical cells. However, complex cells show far more overlap in edge discharge zones than either on- or off-center Y-LGN cells. This comparison suggests spatially overlapping input to complex cells from both on-and off-center Y-LGN cells. A third type of cortical cell (in area 18) demonstrated edge and static-bar responses that strongly resembled those of either on-or off-center Y-LGN cells. Input to these parastriate cortical cells apparently derives from either on-or off-center Y-LGN cells. We believe that these units represent the parastnate equivalent of striate simple units in that they seem to receive inputs from spatially segregated RF areas, in this case of Y-LGN units.     

Alcohol consumption, smoking, and subsequent risk of colorectal cancer in middle-aged and elderly Japanese men and women: Japan Public Health Center-based prospective study.

Few studies have examined the association of alcohol consumption and cigarette smoking with colorectal cancer in Asian populations whose genetic susceptibility to these factors are different from Western populations. We investigated this association and the joint effect of these factors, and estimated the population-attributable fraction to clarify the public health impact on a Japanese population, based on a prospective study. We analyzed the 10-year (cohort I) and 7-year (cohort II) follow-up data of the Japan Public Health Center-based prospective study on cancer and cardiovascular disease, derived from 90,004 (42,540 male and 47,464 female) middle-aged and elderly Japanese. We identified 716 (457 in men and 259 in women) newly diagnosed cases of colorectal cancer. Both alcohol consumption and smoking were clearly associated with colorectal cancer in men, after adjusting for age, family history of colorectal cancer, body mass index, and physical exercise. Regular heavy drinking of 150 g/week or more of ethanol showed a statistically significant increased risk compared with nondrinkers: relative risks (RRs) were 1.4 [95% confidence interval (CI), 1.1-1.9] for 150-299 g/week and 2.1 (95% CI, 1.6-2.7) for 300 g/week or more. On the contrary, regular ethanol consumption was not associated with colorectal cancer (RR, 0.7; 95% CI, 0.4-1.1) in women. In terms of smoking, the RRs were 1.4 (95% CI, 1.1-1.8) for current smokers and 1.3 (95% CI, 0.98-1.7) for ex-smokers compared with never-smokers in men. The risk of smoking in women was similar to that in men, although not statistically significant. The colorectal cancer risk with 300 g/week or more of ethanol in current smokers was estimated at 3.0 (95% CI, 1.8-5.1) compared with nondrinkers among nonsmokers in men. Colorectal cancer attributable to alcohol consumption or smoking was estimated to be 46%. In conclusion, approximately half of the colorectal cancer cases may be preventable by tobacco and alcohol controls in middle-aged and elderly Japanese men.     

Staphylococcal enterotoxin-specific IgE antibodies in atopic dermatitis

BACKGROUND: The authors clarified the clinical significance of the measurement of serum concentrations of specific IgE antibodies to staphylococcal enterotoxin (SE) A- and SEB in atopic dermatitis (AD). METHODS: The serum concentrations of SEA- and SEB-specific IgE antibodies in 140 pediatric patients with AD were measured with an immuno CAP -radioallergosorbent test system (RAST). To check the cross-reaction of specific IgE antibodies to SEA/SEB and other allergens, the CAP RAST fluorescent enzyme immunoassay inhibition test was performed. RESULTS: Forty-seven patients (33.6%) tested positive for either SEA- or SEB-specific IgE antibodies. School children showed higher positive rates of SEA/SEB-specific IgE antibodies than infants or young children. The patients with severe AD and those with exacerbation of symptoms in summer, had higher positive rates of SEA/SEB-specific IgE antibodies than patients with mild AD or those with exacerbation in winter. In addition, the positive rates of specific IgE antibodies to both dog-dander and cat-dander were higher in patients with positive SEA/SEB-specific IgE antibodies than in patients with negative ones. No cross-reactions occurred among specific IgE antibodies to SEA/SEB and dog/cat dander with one patient's serum, which had positive IgE-specific antibodies against cat/dog dander and SEA/SEB. The positive rate of SEA/SEB-specific IgE antibodies in the patients with dogs and/or cats as pets was 48.4%, which was higher than in those with no pets. CONCLUSIONS: Atopic dermatitis patients who exhibit high positive rates of SEA/SEB-specific IgE antibodies were found to be school children, severe cases, cases with high serum concentrations of total IgE, cases with exacerbation in summer, and cases with dogs and/or cats as pets. The measurement of serum concentrations of specific IgE antibodies to SEA and SEB, thus has some value for evaluating AD patients.     

Depression among caregivers of the frail elderly in urban Japan

A cross-sectional study was conducted in order to investigate the various factors related to the depression in caregivers of the elderly in need of care in urban Japan. The caregivers answered a self-administered questionnaire about various factors that may affect their depression, and also completed a Center for Epidemiologic Studies Depression Scale evaluation (CES-D). Compared with non-depressed caregivers, depressed caregivers attended the elderly longer, while time spent for physical caregiving did not differ between the two groups. Even after controlling confounding factors, time of attending the elderly was an independent factor related to caregiver's depression.     

Watershed infarction associated with dementia and cerebral atrophy

A 63-year-old man was admitted with progressive left hemiparesis and left homonymous hemianopsia of 1 month's duration. During the 2 months before admission, he had suffered from slowly progressive dementia. The diagnosis of right-sided watershed (WS) infarction was made. He exhibited slow progression of dementia and cerebral atrophy during the period of observation after discharge. There was a positive relationship between cerebral atrophy and the degree of dementia. In the present case, WS infarction caused by right internal carotid artery occlusion might be related to dementia and cerebral atrophy.