Takayuki Matsuki

An unusual case of primary effusion lymphoma in a HIV-negative patient not pathogenetically associated with HHV8.

Abstract: The development of an unusual case of primary pleural effusion in a 90‐year‐old human immunodeficiency virus (HIV)‐negative Japanese woman with no identifiable tumor mass has been described. Pleural effusion specimens contained large diffuse lymphoma cells, with the phenotype and genotype of a B‐cell lineage (positive for CD20, CD79a and clonal rearrangement of Ig heavy chain) and the c‐myc gene rearrangement, but were negative for T‐cell markers (CD45RO and CD3). The patient was negative for human herpes virus 8 (HHV8), Epstein–Barr virus (EBV) and hepatitis C virus (HCV), as well as human T‐cell lymphotropic virus type‐1 (HTLV‐1). The patient died of respiratory failure 5 months after the diagnosis of primary effusion lymphoma (PEL), and an autopsy was performed. Autopsy findings revealed no evidence of tumor mass or bone marrow involvement of lymphoma cells. This case has been considered as a PEL in a HIV‐, HHV8‐, EBV‐ and HCV‐negative patient. Although cytomorphology of lymphoma cells was classified as large‐cell lymphoma in this case, it is interesting that the present case may represent an unusual subset of Burkitt‐like disease because of clear B‐cell phenotype and c‐myc gene rearrangement.

Prognostic value of fatty acid imaging in patients with angina pectoris without prior myocardial infarction: comparison with stress thallium imaging

A fatty acid analogue, 123I-labelled β-methyl iodophenyl pentadecanoic acid (BMIPP), has been used to identify ischaemic and metabolically impaired myocardium. However, the prognostic value of BMIPP imaging, particularly in relation to stress myocardial perfusion imaging, remains unclear. Data from 167 consecutive patients with angina pectoris but without prior myocardial infarction (MI) who had undergone both BMIPP and stress 201Tl (sTL) imaging were analysed. Tracer uptake was graded using a 13-segment, 4-point scoring model. Patients were followed up for 48 months with primary end points (cardiac death, non-fatal MI) as hard cardiac events and with secondary end points (late revascularisation, recurrent angina and heart failure) as soft events. For overall cardiac events (5 hard and 29 soft events), Kaplan-Meier analysis revealed significantly lower event rates in subgroups with normal BMIPP uptake, a summed difference score of sTL (SDS) of <3 or absence of diabetes mellitus when compared to each counterpart. Multivariate Cox’s analysis revealed reduced BMIPP uptake, SDS ≥3, diabetes and reduced ejection fraction to be significant predictors. Negative predictive values of normal BMIPP and SDS <3 for all events were 91% and 84%, respectively. No hard event occurred in 66 patients with normal BMIPP uptake, whereas two patients with SDS <3 but impaired BMIPP uptake had hard events. In conclusion, normal BMIPP imaging is an excellent prognostic sign, independently of stress myocardial perfusion imaging, in patients with angina pectoris without prior MI.

Assessment of Lower Limb Ischemia With Measurement of Skin Perfusion Pressure in Patients on Hemodialysis

Abstract:  Measurement of skin perfusion pressure (SPP) using laser Doppler has become available for the assessment of peripheral arterial disease. We studied whether measurements of SPP can be used to identify hemodialyzed patients with peripheral arterial disease by comparing it with measurements of the ankle brachial pressure index (ABI). The ABI at rest and the SPP in the foot were measured in 59 Japanese hemodialyzed patients (118 limbs). Twenty‐one patients had diabetes mellitus. Five had intermittent claudication; however, 20 patients were accompanied by other exertional leg symptoms. The SPP could not be measured in three limbs because of involuntary movement due to previous stroke or restless leg syndrome. The SPP was correlated with the ABI. Depending upon these results of the ABI, the 114 limbs from which both the ABI and the SPP could measured were divided into three groups: (A) ABI ≥ 1.3, (B) 0.9 ≤ ABI < 1.3, and (C) ABI < 0.9. The average SPP of group C was significantly decreased among the three groups. All subjects of the three groups were divided into an extra two groups according to the presence of diabetes (non‐diabetes groups, ‐I; diabetes groups, ‐II). The average SPP of group B‐II was significantly decreased compared with those of group B‐I. The SPP measurement is a noninvasive, useful screening method for limb ischemia that can be applied to exercise tolerance limited patients. The SPP measurements are expected to be useful for the evaluation of limb ischemia in hemodialyzed patients at risk.

Angiotensin-converting enzyme inhibitors and the kallikrein-kinin system.

The role of plasma kinin in the hypotensive mechanism of angiotensin-converting enzyme (ACE) inhibitors in essential hypertensive patients and in a dog myocardiac ischemic model is discussed. Both an increase in plasma kinin and a decrease in plasma angiotensin II might contribute to the hypotensive effects of ACE inhibitors in a normal-renin group. In a low-renin group, the hypotensive mechanism of this drug may he mainly the increase in plasma kinin levels. The augmentation of urine volume and urinary sodium excretion may also be related to the hypotensive effects of ACE inhibitors, and this mechanism might be explained by the renal blood flow increase and augmented activity in the renal kallikrein-kinin system. In a dog myocardial ischemia model, when an apparent myocardial ischemia occurred in the constricted group, plasma kinin levels in coronary sinus blood increased significantly. Following infusion of kinin into the left main coronary artery, 0.1 ng/kg/min of kinin for 5 min did not cause any change in plasma kinin levels in the artery or coronary sinus. A dose of 10 ng/kg/min of kinin for 5 min produced a significant elevation in plasma kinin in the coronary sinus from 12.8 to 142 pg/ml without any change in plasma kinin in the artery. However, such a level of kinin had no significant effect on coronary circulation, myocardial metabolism, or ECG ST segment in either group. Thus, the role of increased kinin in this dog model still remains unclear. Further studies including the administration of ACE inhibitors or bradykinin antagonist will be necessary to reach conclusions about the role of kinin in the heart.

Free-radical scavengers preserve wall motion in the xanthine oxidase-deficient rabbit heart

We investigated the role of free radicals in postischemic segmental dysfunction in the rabbit, a species that, like the human, has undetectable amounts of xanthine oxidase in its heart. Open-chest anesthetized rabbits were instrumented with 0.5-mm diameter sonomicrometer crystals to measure myocardial segment shortening. Occlusion of a left coronary branch for 20 minutes caused dyskinesis in the field of the occluded artery, but after reperfusion, over 40% of that function returned. Although either 15,000 U/kg body weight of human recombinant superoxide dismutase (hSOD) alone or 5000 U/kg of catalase alone (each infused intravenously over 90 minutes starting 15 minutes before occlusion) failed to improve postischemic segmental shortening, the combination of hSOD and catalase did improve postischemic shortening. Most hearts had small infarcts. Analysis of the relationship between infarct size and regional function indicated that infarction alone could not account for all of the dysfunction and that some stunning must have been present. Whether the combination of hSOD and catalase improved wall motion by reducing infarct size or reducing stunning could not be determined. We conclude that rabbit heart is similar to dog heart in that free radicals contribute to postischemic dysfunction, but that rabbit heart is more resistant to stunning.

Clinical Performance of a Salivary Amylase Activity Monitor During Hemodialysis Treatment

The hemodialysis procedure is thought to be a physical stressor in the majority of hemodialyzed patients. Previous studies suggest that elevated salivary amylase level may correlate with increased plasma norepinephrine level under psychological and physical stress conditions. In this study, we investigated biological stress reactivity during hemodialysis treatment using salivary amylase activity as a biomarker. Seven patients (male/female = 5/2, age:67.7+/–5.9 years) who had been receiving regular 4 h hemodialysis were recruited. Salivary amylase activity was measured using a portable analyzer every hour during the hemodialysis session. Salivary amylase activity was shown to be relatively stable and constant throughout hemodialysis, whereas there were significant changes in systolic blood pressure and pulse rate associated with blood volume reduction. Our results show that hemodialysis treatment per se dose not affect salivary amylase activity.