Oxygen Equilibrium Characteristics of Abnormal Hemoglobins: Hirose (α2β237Ser), L Ferrara (α247Glyβ2), Broussais (α290Asnβ2), and Dhofar (α2β258Arg)

The oxygen equilibrium characteristics of four structural variants of hemoglobin A were correlated with their amino acid substitutions.Hemoglobin Dhofar, in which the proline at E2(58)beta is replaced by arginine, had normal oxygen equilibrium characteristics.Hemoglobin L Ferrara. in which the aspartic acid at CD5(47)alpha is replaced by glycine, and hemoglobin Broussais, in which the lysine at FG2(90)alpha is replaced by asparagine, both showed a slightly elevated oxygen affinity; nevertheless both demonstrated a normal heme-heme interaction and a normal Bohr effect.Hemoglobin Hirose, in which the tryptophan at C3 (37)beta is replaced by serine, showed abnormalities of all oxygen equilibrium characteristics; i.e., increased oxygen affinity, diminished heme-heme interaction, and reduced Bohr effect.These results suggest that aspartic acid at CD5(47)alpha and lysine at FG2(90)alpha are involved in the function of the hemoglobin molecule, despite the fact that these positions are not located directly in the heme or the alpha-beta-contact regions.Tryptophan at C3(37)beta is located at contact between alpha(1)- and beta(2)-subunits. It is suggested that the substitution by serine might disturb the quarternary structure of the mutant hemoglobin molecule during transition from oxy-form to deoxy-form resulting in an alteration of the heme function.     

Detection of Legionella pneumophila serogroup 7 strain from bathwater samples in a Japanese hospital

Hospital-acquired legionellosis is one of the serious problems in nosocomial infection. For risk assessment of nosocomial Legionella infection, we surveyed samples from bathrooms for public use in three hospitals and two nursing homes to determine whether Legionella pneumophila was present. A total of 70 hot bathwater samples and samples wiped from bathtubs were collected at 1-h intervals. Fifteen shower-water and 15 inner-head samples were obtained at the start of a bath. Water samples were cultured using the Legionella spp. selective medium, and discrimination between L. pneumophila and other Legionella spp. was performed by PCR analysis. L. pneumophila serogroup 7 was detected in 1 bathwater and 1 wiped sample, both of which were collected 1 h after daily use from the same bathtub in a hospital. However, L. pneumophila SG7 was not detected in any other samples. Furthermore, the concentrations of free residual chlorine in most bath- and shower-water samples were lower than 0.1 mg/l. These results suggest that L. pneumophila has become a potential pathogen for nosocomial infections in public-type hospital baths. From the point of view of an infection-control program, it might be advisable to hold the concentration of free residual chlorine at 0.2–0.4 mg/l, which is generally required for public baths in Japan.     

Annular dynamics of memo3D annuloplasty ring evaluated by 3D transesophageal echocardiography

Background

We assessed the mitral annular motion after mitral valve repair with the Sorin Memo 3D® (Sorin Group Italia S.r.L., Saluggia, Italy), which is a unique complete semirigid annuloplasty ring intended to restore the systolic profile of the mitral annulus while adapting to the physiologic dynamism of the annulus, using transesophageal real-time three-dimensional echocardiography.

Methods

17 patients (12 male; mean age 60.4?±?14.9 years) who underwent mitral annuloplasty using the Memo 3D ring were investigated. Mitral annular motion was assessed using QLAB®version8 allowing for a full evaluation of the mitral annulus dynamics. The mitral annular dimensions were measured throughout the cardiac cycle using 4D MV assessment2® while saddle shape was assessed through sequential measurements by RealView®.

Results

Saddle shape configuration of the mitral annulus and posterior and anterior leaflet motion could be observed during systole and diastole. The mitral annular area changed during the cardiac cycle by 5.7?±?1.8%.The circumference length and diameter also changed throughout the cardiac cycle. The annular height was significantly higher in mid-systole than in mid-diastole (p?<?0.05).

Conclusions

The Memo 3D ring maintained a physiological saddle-shape configuration throughout the cardiac cycle. Real-time three-dimensional echocardiography analysis confirmed the motion and flexibility of the Memo 3D ring upon implantation.

     

Extracorporeal double filtration plasmapheresis in acute atherothrombotic brain infarction caused by major artery occlusive lesion

Extracorporeal double filtration plasmapheresis (EDFP) can quickly lower plasma viscosity and fibrinogen concentration. EDFP has the potential to improve cerebral microcirculation in acute ischemic stroke and ultimately to salvage penumbral tissue. However, no evidence is available to show that EDFP can increase cerebra blood flow (CBF). Therefore, we investigated whether EDFP could increase CBF by quantitative CBF measurements and documented the clinical effects of EDFP in acute ischemic stroke. EDFP was performed ten times in seven patients diagnosed as having acute atherothrombotic brain infarction caused by major artery occlusive lesion. They also fulfilled one of the following entry criteria: 1) diffusion/perfusion mismatch demonstrated by MRI on admission; 2) a hemispheric syndrome, but only a small lesion on diffusion weighted MRI (<25% of MCA territory); or 3) progressing stroke. Exclusion criteria were 1) contraindication of heparin or 2) spontaneous improvement of symptoms. Time from stroke onset to EDFP varied from 5 hr to 7 days. Plasma viscosity was quickly lowered by EDFP without affecting RBC counts, Hb, or Hct in all patients. Positron emission tomography (PET) with 15-O labeled H2O measurements revealed a significant CBF increase from 36.4 +/- 8.3 ml/100 g/min to 40.7 +/- 6.8 ml/100 g/min in the affected hemisphere (P=0.048). Definite CBF improvement was also demonstrated by single photon emission computed tomography (SPECT) in one of two patients who had severe stenosis of the middle cerebral artery. Furthermore, this patient showed remarkable improvement of hemiplegia immediately following EDFP (NIHSS score: 18 to 13). In conclusion, EDFP can increase CBF in ischemic brain tissue in acute atherothrombotic brain infarction. Further clinical studies should focus on the efficacy of EDFP on outcome of patients with this stroke subtype.     

Studies in Porphyria: VII. INDUCTION OF UROPORPHYRINOGEN-I SYNTHASE AND EXPRESSION OF THE GENE DEFECT OF ACUTE INTERMITTENT PORPHYRIA IN MITOGEN-STIMULATED HUMAN LYMPHOCYTES

A 50% reduction in the activity of uroporphyrinogen-I (URO) synthase in liver, erythrocytes, and cultured skin fibroblasts characterizes all patients with clinically active acute intermittent porphyria (AIP). The same enzyme defect has also been demonstrated in the erythrocytes and skin fibroblasts of completely latent gene carriers of this disorder and presumably exists in the liver as well.     

The effects of the extent of spinal block on the BIS score and regional cerebral oxygen saturation in elderly patients: A prospective,randomized, and double-blinded study

Backgrounds Patients may become sedated with␣spinal anesthesia; however, the effect of the extent of␣spinal block on the Bispectral index (BIS), a processed electroencephalographic variable, has not been fully investigated. We evaluated the influence of the extent of spinal block on BIS values and on regional cerebral oxygen saturation (rSO₂) in elderly patients. Methods A prospective, randomized, double-blinded study was performed in 55 ASA II patients undergoing urological surgery. The patients were randomly allocated into one of two groups to receive 2.7 ml of 0.5% hyperbaric bupivacaine or 1.5 ml, and then divided into two groups according to level of spinal blockade: high spinal group (Th6 and above) or low spinal group (Th12 and below). Systolic blood pressure (SBP), heart rate (HR), cardiac output (CO), stroke volume (SV), BIS values, and rSO₂ were measured for 30 min. CO and SV were evaluated using impedance cardiograph methods. Results The level of spinal blockade was Th4.7 ± 1.0 in high spinal group (n = 20) and L2.5 ± 2.2 in low spinal group (n = 20). High spinal anesthesia produced a significant decrease in SBP (p < 0.01) and SV (p < 0.01), but had no effect on CO. High spinal anesthesia significantly decreased BIS values (p < 0.01) without affecting rSO₂. There was relationship between level of spinal blockade and BIS values (r = 0.566). In contrast, no changes in above parameters were found in low spinal group. Conclusions This study provides evidence that the extent of spinal block may have significant influence on BIS values without affecting rSO₂ in elderly patients. A part of the present study was presented at the Annual Meeting of the Japan Society of Anesthesiologists, June 02–04, 2005 at Kobe, Japan. Nishikawa K,Hagiwara R, Nakamura K, Ishizeki J, Kubo K, Saito S, Goto F. The effects of the extent of spinal block on the BIS score and regional cerebral oxygen saturation in elderly patients: A prospective, randomized, and double-blinded study.     

Plasma Lactic Acid and Pyruvic Acid Levels in Migraine and Tension-Type Headache

We examined the lactic and pyruvic acid levels in the plasma of 14 patients with migraine, 17 patients with tension-type headache, and 12 normal controls. The lactic and pyruvic acid levels in the plasma of the migraine patients were significantly higher than those of the normal controls (9.6 ± 5.0 mg/dL and 0.51 ± 0.30 mg/dL versus 3.3 ± 1.9 mg/dL and 0.26 ± 0.20 mg/dL, respectively). There were no significant differences in the levels between the patients with tension-type headache and normal controls. Our results suggest that migraine patients may have functional abnormalities in mitochondrial energy metabolism.     

Increase in plasma concentration of ubiquitin in dialysis patients: Possible involvement in β2-microglobulin amyloidosis

β₂-Microglobulin(β2-M) amyloidosis is a serious complication of dialysis therapy; however, its pathogenesis is still unclear. Recent studies have indicated that ubiquitin has amyloid enhancing factor activity, raising the possibility that ubiquitin plays a role in β2-M amyloidogenesis. In this study, synovial tissue from patients with long-term dialysis was examined immunohistochemically. The synovial tissue was labeled with anti-ubiquitin antibody, indicating co-deposition of ubiquitin with β2-M amyloid. To elucidate the involvement of plasma ubiquitin, we established a specific radioimmunoassay for ubiquitin. Using this method, we observed that the plasma concentration of ubiquitin-like immunoreactivity in dialysis patients was significantly higher than that in normal subjects. In chronic renal failure patients, the plasma concentration of ubiquitin-like immunoreactivity was also significantly higher than that in normal controls, which finding suggests that a reduction in renal clearance is, at least in part, responsible for the increased plasma concentration of ubiquitin. In dialysis patients, plasma concentrations of ubiquitin-like immunoreactivity in patients with carpal tunnel syndrome, one of the major symptoms of β2-M amyloidosis, were significantly higher than those in patients not exhibiting this syndrome. These results suggest a possible involvement of plasma ubiquitin in β2-M amyloidosis.