The relationship between cerebral white matter changes, mental function and blood pressure in normal elderly

The authors examined the relationship between cerebral white matter changes and mental function, blood pressure in 39 neurologically normal aged (21 males, 18 females, mean age 75.0 years) who had no latent lesions on MRI images. The severity of cerebral white matter changes was estimated by T1 value images on MRI and was measured in the bilateral frontal lobe on an axial slice at the level of the basal ganglia and in the bilateral anterior, middle, and posterior portions on axial slices at the level of the body of the lateral ventricle. Mental function was measured by the Hasegawa's dementia rating scale (HDS) and Kohs' block design test (Kohs' test). The severity of cerebral frontal white matter changes increased significantly with age (p less than 0.05). However there was no significant correlation between the severity of cerebral white matter changes and HDS, Kohs' test. The severity of frontal white matter changes correlated with the mean arterial blood pressure (p less than 0.02). These results suggest that the severity of cerebral white matter changes is not related with mental function in the normal elderly, and that the severity of frontal white matter lesions is related with mean arterial blood pressure.     

Platelet glutathione peroxidase activity in long-term total parenteral nutrition with and without selenium supplementation.

Selenium (Se) is not routinely included in total parenteral nutrition (TPN) solution; thus, patients receiving long-term TPN may be at risk of Se deficiency, which may cause fatal cardiomyopathy. Platelet glutathione peroxidase (GSH-Px) activity, as well as Se levels and GSH-Px activity in plasma and erythrocytes during prolonged TPN, was measured in six patients with chronic gastrointestinal disease. During the time course of TPN, Se administration was discontinued for 12 weeks, and then resupplemented for another 12 weeks. Before the study period, all Se indices had been maintained within the normal range. After discontinuation of Se supplementation, a significant decrease in platelet GSH-Px activity was observed after 1 week (from 64 +/- 7 [mean +/- SD] to 39 +/- 5 U/g of protein). After resupplementation, it increased after 1 week (from 44 +/- 9 to 65 +/- 10 U/g of protein). Plasma Se indices significantly changed within 3 weeks after withdrawal and reintroduction of Se (Se: from 136 +/- 28 to 75 +/- 14 and from 61 +/- 22 to 125 +/- 33 micrograms/L; GSH-Px: from 236 +/- 50 to 140 +/- 36 and from 128 +/- 32 to 220 +/- 64 U/L). Erythrocyte Se indices showed no significant changes during the study period. The results demonstrate that platelet GSH-Px activity is the most sensitive index of Se status in TPN patients.     

Near-infrared spectroscopy for monitoring cerebral ischemia during selective cerebral perfusion.

OBJECTIVE: To minimize the neurological complications following cardiovascular surgery, it is essential to prevent an occurrence of cerebrovascular embolism and to detect and solve cerebral malperfusion without delay in the operating theater. Although we have introduced near-infrared spectroscopy (NIRS) monitoring for the purpose of detecting cerebral malperfusion, no criterion has been available. We searched for this criterion by examining the relationship of sustained drop in the regional oxygen saturation (rSO2) of the frontal lobes to the occurrence of neurological events. METHODS: The 59 consecutive patients undergoing aortic surgery with selective cerebral perfusion (SCP) were examined. The rSO2 was monitored throughout the surgery and the durations of drops in rSO2 to below 55% and those below 60% were determined for each patient. The durations of rSO2 drop and other surgery-related parameters were compared between the patients in whom neurological events occurred and those without such events. RESULTS: A total of 16 cases (27.1%) presented with neurological events. Newly developed cerebral infarction was documented in 6 of these 16 cases. Operation time and the durations for which rSO2 dropped were significantly longer for the 16 patients with neurological events than for the 43 patients without events (Op time: 546.8 versus 448.1 min, P=0.0064; rSO2 below 60%: 141.2 versus 49.8 min, P=0.0032; rSO2 below 55%: 66.6 versus 10.6 min, P=0.0011), while there was no significant difference in age, bypass time, aortic clamping time, SCP time, and circulatory arrest time between the two groups. In the 3 patients with infarcts suggestive to hypoperfusion, sustained decrease in rSO2 was observed, while it was not significant in the remaining 3 patients with infarcts suggestive to embolism. Among the 53 patients without infarction, transient neurological events occurred more frequently in patients with sustained drop in rSO2 below 55% for over 5 min (44.4% versus 5.7%, P=0.0014). CONCLUSIONS: A sustained drop in rSO2 during aortic surgery is closely related to the occurrence of neurological events following surgery. We recommend that recovery of drop in rSO2 below 55% should be addressed without delay. However, use of NIRS is limited for detecting embolic events or hypoperfusion in the basilar region.     

M protein and protein F act as important determinants of cell-specific tropism of Streptococcus pyogenes in skin tissue.

The pathogenic gram-positive bacterium Streptococcus pyogenes (group A streptococcus) causes numerous diseases of cutaneous tissue, each of which is initiated after the interaction of the bacterium with the cells of the epidermis. In this study, we show that different surface proteins of S. pyogenes play important roles in determining the cell-specific tropism of the bacterium in skin. Using streptococcal strains with defined mutations in the genes which encode surface proteins in combination with primary cultures of human skin and an in situ adherence assay which uses histological sections of human skin, we show that the M protein of S. pyogenes mediates the binding of the bacterium to keratinocytes, while a second streptococcal surface protein, protein F, directs the adherence of the organism to Langerhans' cells. Characterization of binding revealed that adherence was inhibited by purified streptococcal proteins and pretreatment of both host cells with the protease trypsin. Adherence was only slightly affected by the state of keratinocyte differentiation in vitro, but was considerably modulated in response to environmental conditions known to regulate expression of M protein and protein F, suggesting that the interaction between these bacterial cell-surface structures/adhesins and keratinocytes and Langerhans' cells may play an important role in streptococcal skin disease.     

Pheochromocytoma discovered in a pregnant woman: a case report]

A case of pheochromocytoma discovered at pregnancy is reported. The patient was a 27-year-old woman who had no symptoms before pregnancy. A sudden hypertensive attack occurred during vaginal examination at the 36th week of pregnancy. Magnetic resonance imaging (MRI) and ultrasonography showed a right adrenal mass. The level of catecholamine in blood and urine was beyond the normal limit. This patient was diagnosed as pheochromocytoma with pregnancy. Cesarean section was immediately done to avoid hypertensive crisis caused by spontaneous delivery. Blood pressure and blood volume were controlled by an alpha-blocker for one month after delivery, and, then the tumor was removed surgically. Pheochromocytoma with pregnancy is life-threatening for the mother and the fetus because of difficult diagnosis and complex clinical features. Early diagnosis and appropriate treatment are mandatory. Pathophysiological characteristics and the treatment of such specified statics are mainly discussed through our successful achievement.     

Body temperature monitoring in subjects with delayed sleep phase syndrome

To clarify the circadian aspects of delayed sleep phase syndrome (DSPS) in 4 patients with DSPS, we recorded polysomnograms and rectal temperature before and after chronotherapy. The time interval (2.7 h) between sleep onset and rectal temperature minimum before chronotherapy was shorter than the time interval after chronotherapy (5.3 h). Before chronotherapy, the period of rectal temperature rhythm was 24.7 h. After chronotherapy, the period of rectal temperature rhythm was 24.0 h. These findings lead to the conclusion that in DSPS there is a weakened mechanism of entrainment similar to that in non-24-hour sleep-wake syndrome.