Acute Type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen

Background:

Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery.

Patients and Methods:

We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months).

Results:

Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3mm) true lumen was associated with a significantly high incidence of MS and mortality.

Conclusions:

High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.

Reduced GFR and albuminuria in Chinese type 2 diabetes mellitus patients are both independently associated with activation of the TNF-alpha system

AIMS/HYPOTHESIS

The involvement of chronic inflammation in albuminuria and renal function was investigated in a cross-sectional study of 320 type 2 diabetic Chinese patients from the Singapore Diabetes Cohort Study.

METHODS

Plasma levels of TNF-alpha and its two cellular receptors and of IL-6 and C-reactive protein (CRP) were measured. A composite TNF-alpha score was extracted using principal component analysis. Multiple linear regression analysis was implemented to evaluate the relationship between log( e ) (ln) albumin:creatinine ratio (ACR) and estimated GFR (eGFR) with the inflammatory variables and other clinical covariates. A Bonferroni correction was applied based on the total number of variables entered into regression analyses.

RESULTS

ln ACR was significantly associated with TNF-alpha score independently of eGFR even after a Bonferroni correction. TNF-alpha score was also significantly associated with eGFR independently of ln ACR even after correction for multiple testing. These findings were similar when the individual molecules of the TNF-alpha system were analysed separately instead of using the composite TNF-alpha score. No association was observed for IL-6 and CRP with either renal trait. Diabetes duration was a significant predictor for ln ACR but not eGFR. Conversely, age was significantly associated with eGFR but not ln ACR.

CONCLUSIONS/INTERPRETATION

Activation of the TNF-alpha system may potentially exert independent effects on ln ACR and eGFR in type 2 diabetes. Because of the study design, one may also consider the possibility that changes in these renal traits may conversely be responsible for such an inflammatory response.

One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up

BACKGROUND

The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass.

METHODS

From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group).

RESULTS

Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years.

CONCLUSIONS

Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

Synergistic effect of tris(4-isopropyltropolonato)cobalt(III) on the extraction of lanthanoid(III) with 2-thenoyltrifluoroacetone

Synergistic enhancement of the extraction of lanthanoid(III) (Ln) with 2-thenoyltrifluoroacetone (Htta) in benzene has been found by the addition of tris(4-isopropyltropolonato)cobalt(III) (Co(ipt)3). The synergistic effect of Co(ipt)3 was ascribed to the formation of a 1:1 adduct of Ln(tta)3 with Co(ipt)3, i.e., a binuclear complex, in the organic phase. The adduct formation constant (beta s,1) determined by the extraction equilibrium analysis was reasonably consistent with that determined by spectrophotometry. The beta s,1 values decreased with increase in the atomic number of Ln and showed a large difference between light and heavy Ln. Spectroscopic studies were performed to explain the difference in the beta s,1 values. Electronic absorption spectra showed that the change in the structure of Co(ipt)3 complexed with the light Ln chelate is larger than that with the heavy Ln. The IR spectra showed the displacement of the coordinated water molecules of the light Ln chelates with Co(ipt)3. On the other hand, the adduct formation of heavy Ln was caused by the hydrogen bonding between Co(ipt)3 and the coordinated water of the Ln chelate.

Age-dependent and hypoxia-related differences in myocardial protection during pediatric open heart surgery

BACKGROUND

Current cardioplegic protection techniques used in pediatric cardiac surgery do not take into consideration age and cyanotic differences. The aim of the present work was to address this question by monitoring clinical outcome, myocardial metabolism, and reperfusion injury in pediatric patients protected by cold-crystalloid cardioplegia.

METHODS AND RESULTS

Fifty-eight patients (31 children and 27 infants) with or without hypoxic stress (cyanosis) undergoing open heart surgery with cold-crystalloid cardioplegia were included in the study. Clinical outcome measures assessed included inotropic and ventilatory support, intensive care, and hospital stay. Ischemia-induced changes in metabolism (adenine nucleotides, purines, lactate, and amino acids) were determined in ventricular biopsies collected at the beginning and end of ischemic time (cross-clamp time). Reperfusion injury was assessed by measuring postoperative serial release of troponin I. Evidence was observed of ischemic stress during cardioplegic arrest in children and infants as shown by significant changes in cellular metabolites. Compared with infants, children had significantly less reperfusion injury and better clinical outcome, and these factors were related to duration of ischemic time. Cyanosis did not influence outcome in infants, but cyanotic children showed worse reperfusion injury and clinical outcome than acyanotic children.

CONCLUSIONS

Extent of myocardial protection with cold-crystalloid cardioplegia in pediatric open heart surgery is dependent on age and degree of cyanosis.

[Perspectives on postgenome medicine in the 21st century]

Since the human genome project has been almost completed in 2000, the year of 2001 is the first year of the postgenomic era. A variety of postgenome studies will be done in the next decade, including functional, comparative and structural genomics. These studies may open new area in medicine, because disease susceptibility and drug metabolism would be predicted from genetic characteristics of individuals. Genome studies may also shed a light on cell biology, brain research and regeneration medicine and promote these studies. Bioinformatics will become a basis of postgenome biology and medicine.

[Introducing EBM for postgraduate training]

The introduction of Evidence-based medicine(EBM) for residency training is recommended by the Japanese Society of Internal Medicine. At our hospital, we put the emphasis on learning vital clinical epidemiology through clinical experience. When educating EBM to our residents, we especially focus on the diagnostic process, because the knowledge of clinical epidemiology is useful while making the diagnosis and evaluating the diagnostic hypothesis. In our daily conference among residents and medical educators, the logic of clinical epidemiology is used for evaluating the validity of clinical judgment on diagnosis. We suggest three components upon making a diagnosis: 1. Always suspect a particular disease when ordering a laboratory test 2. Know the sensitivity and specificity of the test 3. Apply the test result in order to reevaluate the pretest hypothesis In this article, interaction among staff and residents are presented and discussed with these components in our minds. By repeating these interactions, the residents will be able to understand the importance of EBM and will be able to apply it in the clinical practice.

Purification and characterization of UDP-glucose: hydroxycoumarin 7-O-glucosyltransferase, with broad substrate specificity from tobacco cultured cells

The enzyme UDP-glucose: hydroxycoumarin 7-O-glucosyltransferase (CGTase), which catalyzes the formation of scopolin from scopoletin, was purified approximately 1200-fold from a culture of 2,4-D-treated tobacco cells (Nicotiana tabacum L. cv. Bright Yellow T-13) with a yield of 7%. Purification to apparent homogeneity, as judged by SDS-PAGE, was achieved by sequential anion-exchange chromatography, hydroxyapatite chromatography, gel filtration, a second round of anion-exchange chromatography, and affinity chromatography on UDP-glucuronic acid agarose. The purified enzyme had a pH optimum of 7.5, an isoelectric point (pI) of 5.0, and a molecular mass of 49 kDa. The enzyme did not require metal cofactors for activity. Its activity was inhibited by Zn(2+), Co(2+) and Cu(2+) ions, as well as by SH-blocking reagents. The K(m) values for UDP-glucose, scopoletin and esculetin were 43, 150 and 25 µM, respectively. A study of the initial rate of the reaction suggested that the reaction proceeded via a sequential mechanism. The purified enzyme preferred hydroxycoumarins as substrates but also exhibited significant activity with flavonoids. A database search using the amino terminus amino acid sequence of CGTase revealed strong homology to the amino acid sequences of other glucosyltransferases in plants.

Wavelength and conduction inhomogeneity in each atrium in patients with isolated mitral valve disease and atrial fibrillation

INTRODUCTION

Patients with mitral valve disease frequently have atrial fibrillation (AF), and the left atrium is presumed to be the primary atrium that develops AF. However, it is still not clear whether the electrophysiologic abnormalities responsible for AF are confined to the left atrium in this subset of patients.

METHODS AND RESULTS

To examine the AF vulnerability of each atrium, we measured the wavelength and inhomogeneity of the conduction at the lateral right atrium, lateral left atrium, and Bachmann's bundle after defibrillation of AF in seven patients undergoing the maze procedure and mitral valve surgery for AF and isolated mitral valve disease, respectively (AF group). The data were compared with five coronary surgery patients in sinus rhythm (SR group). The wavelength in the AF group was significantly shorter (P < 0.05) than in the SR group not only at the lateral left atrium (225 +/- 62 vs 285 +/- 36 mm) but also at the lateral right atrium (214 +/- 54 vs 254 +/- 34 mm). The variation coefficient of the local maximum activation phase difference in the AF group (1.9 +/- 0.8 at the right atrium, 2.1 +/- 0.8 at the lateral left atrium, and 2.0 +/- 0.6 at Bachmann's bundle) was significantly greater (P < 0.05) than in the SR group at all atrial regions.

CONCLUSION

AF vulnerability was not confined to the left atrium immediately after defibrillation in AF patients with isolated mitral valve disease. Electrical remodeling resulting from perpetuation of AF, pathological changes extending to the right atrium, geometric changes caused by the atrial interactions occurring across the interatrial septum, or a combination of these may explain the results.

A case of oophoritis detected by gallium-67-citrate scintigraphy

A 39-year-old woman with fever of unknown origin was admitted to our hospital. Whole body scintigrams with 67Ga-citrate showed an abnormal accumulation of radioactivity in the pelvic cavity. Cystadenocarcinoma of the ovary was suspected on the basis of findings obtained by abdominal computed tomography and magnetic resonance imaging. Left oophorectomy was performed, and oophoritis was diagnosed. We would like to propose that 67Ga-citrate scintigraphy may be useful for the diagnosis of oophoritis as well as gynecologic malignant tumors.

[Recent progress in clinical aspects of receptor research]

Clinical receptology encompasses broad areas, including receptor or postreceptor defects due to mutations of receptor or other genes, abnormalities due to receptor antibodies and secondary changes of receptors under various pathological conditions. Recent progress in molecular biology has succeeded in cloning genes of receptors, G-proteins and other cellular proteins that are involved in the signal transduction and clarified their germ-line and somatic mutations. It is of importance that mutations of receptors and G-proteins do not necessarily cause loss of function but sometimes cause gain of function of receptors or G-proteins, thus leading to hyperfunction. Molecular basis that causes either loss or gain of function has been studied but is not completely understood. Some examples of gain of function mutatious of G-protein coupled receptors, tyrosin kinase-type receptors and G alpha protein are shown. Another important aspect in receptor research is that mutation of a single receptor gene sometimes result in different phenotypes and even different modes of inheritance. For example, mutations of rhodopsin (a G-protein coupled receptor) gene cause retinitis pigmentosa of autosomal dominant type and autosomal recessive type and also cause congenital stationary night blindness. Exact mechanisms responsible for such differences are not completely understood. There are polymorphisms in some genes that may be involved in some diseases. An example is a polymorphism in beta 3-adrenergic receptor that is claimed but not clearly demonstrated to be a cause of obesity or type II diabetes. Such polymorphism is possibly a gene in polygenic diseases. Receptology is important for elucidating pathogenesis of complex diseases.

Simultaneous surgical correction of a common atrium and impure flutter

We performed surgical correction and treatment of a common atrium and chronic impure flutter using a computerized mapping system in a 49-year-old man. A reentrant circuit was observed to exist around the left atrial appendage. In contrast to the regular activation in the left atrium, the activation sequence of the right atrium was extremely chaotic. Cryolesions were applied to the area of the reentrant pathway. After the operation, sinus rhythm was restored.