Postischemic recovery of mitochondrial adenine nucleotides in the heart.

BACKGROUND. Adenine nucleotides (AdNs) are lost from the mitochondrial fraction of the heart cell during ischemia. It is unknown whether this pool of AdNs can be replenished after reperfusion. The purpose of this study was to evaluate the postischemic recovery of the mitochondrial AdN pool. METHODS AND RESULTS. The left anterior descending coronary artery (LAD) of the canine heart was occluded for 30 minutes followed by either no reflow, 30-minute reflow, 1-day reflow, or 7-day reflow. Systolic shortening in the LAD-supplied region was absent during occlusion but recovered to approximately 30% of preocclusion values during early reperfusion. Mitochondrial and tissue AdNs (ATP, ADP, and AMP) were determined in the LAD-supplied and left circumflex-supplied (control) regions of the heart. The AdN content (expressed as percent of control values) of mitochondria from the LAD region was 55 +/- 10% (p less than 0.002), 64 +/- 7% (p less than 0.001), 81 +/- 6% (p less than 0.03), and 94 +/- 8% for the no-reflow, 30-minute-reflow, 1-day-reflow, and 7-day-reflow groups, respectively. The AdN content (expressed as percent of control values) of tissue samples from the LAD region was 52 +/- 9% (p less than 0.002), 48 +/- 12% (p less than 0.02), 68 +/- 5% (p less than 0.002), and 70 +/- 9% for the no-reflow, 30-minute-reflow, 1-day-reflow, and 7-day-reflow groups, respectively. There was a good correlation between mitochondrial and tissue AdN (r = 0.95). Using initial exchange rates, adenine nucleotide translocase activities of mitochondria from the LAD and control regions were not significantly different. State 3 respiration of LAD mitochondria was depressed (approximately 25%, p less than 0.05) only in the no-reflow group. Acceptor control ratios of the LAD mitochondria were not significantly different from control values in any group. CONCLUSIONS. After 30 minutes of regional ischemia, postischemic restoration of the mitochondrial AdN pool occurs between 1 and 7 days; this restoration is preceded by recovery of respiratory and adenine nucleotide translocase functions. Although the abnormally low levels of AdN persist in the mitochondrial compartment during the early reperfusion period, postischemic contractile dysfunction cannot be explained by depressed mitochondrial respiratory activity.     

Association between TNF-alpha -308G>A polymorphism and the development of acute coronary syndromes in Greek subjects: the CARDIO2000-GENE Study.

PURPOSE: We investigated the association of a polymorphism within the promoter of TauNuF-alpha locus at the position -308 on the likelihood of having acute coronary syndromes (ACS) in Greek adults. METHODS: We studied demographic, lifestyle, and clinical information in 237 hospitalized patients (185 males) with a first event of an ACS and 237 matched by age and sex (controls) without any clinical evidence of coronary heart disease. Genotyping was performed by PCR-RFLP analysis. RESULTS: The genotype frequencies were in patients, 87% (n = 206), 12% (n = 29), and 1% (n = 2) for G/G, G/A, and A/A, and in controls, 96% (n = 227), 4% (n = 10), and 0% (n = 0) for G/G, G/A, and A/A, respectively (P = 0.04). After adjusting for age and sex, as well as various potential confounders, we observed that G/A or A/A genotypes were associated with 1.94-fold higher odds (95% CI 1.06 to 3.68) of ACS compared to G/G homozygotes. No gene to-gender or to-clinical syndrome interactions were observed. Further subgroup analysis showed that the distribution of TNF-alpha -308G>A polymorphism was associated with the presence of family history of CHD in patients, but not in controls. In particular, in G/A and A/A patients 17.2% reported family history of CHD, whereas in G/G patients, 34.5% reported family history (P = 0.036). CONCLUSIONS: Our findings may state a hypothesis of an association between the -308G>A TNF-alpha polymorphism the development of ACS and the presence of family history of CHD, in Greece.     

Primary Malignant Fibrous Histiocytoma of the Spleen-an Extremely Rare Entity

Malignant fibrous histiocytoma (MFH) is a frequently occurring soft tissue tumour with aggressive biological behaviour. Primary MFH of the spleen, however, is an exceedingly rare occurrence. Herein, we report a case of such a neoplasm in a 66-year-old female. The tumour was well localised within the spleen and the patient remains alive and well 34 months after splenectomy without any adjuvant therapy. A brief discussion and review of the few cases of primary splenic MFH previously reported in the English language literature is included.     

Two independent sources of anisotropy in the visual representation of direction in 2-D space

It is known that visual direction representation is more accurate for cardinal directions compared to oblique, a phenomenon named the “oblique effect”. It has been hypothesized that there are two sources of oblique effect, a low level one confined to vision and a high level one extending to different modalities and corresponding to higher cognitive processes. In this study directional error (DE) was measured when normal individuals tried to align the direction of an arrow presented in the center of a computer monitor to the direction of a peripheral target located in one of 32 directions equally spaced on an imaginary circle of 60 mm radius. Task difficulty was manipulated by varying arrow length (15, 30, 45 and 60 mm). By measuring mean DE and its variance we identified two independent sources of the oblique effect. A low level oblique effect was manifested in higher accuracy or equivalently lower variance of DE in the alignment for cardinal orientations compared to oblique. A second oblique effect was manifested measuring mean DE resulting in space expansion in the vicinity of cardinal directions and space contraction in the vicinity of oblique directions. Only this latter source of oblique effect was modulated by arrow length as predicted from a theoretical model postulating that this oblique effect is produced by a cognitive process of 2-D space categorization.     

Rapid salvage treatment with virus-specific T cells for therapy-resistant disease

Background.?Viral infections are major complications after allogeneic hematopoietic stem cell transplantation (HSCT). During posttransplant immunosuppression the regular T-cell control is compromised. Even if treatment strategies against infections caused by herpes viruses such as cytomegalovirus, Epstein-Barr virus, and adenovirus have improved, the mortality rate is still considerable. If primary antiviral therapy fails or cannot be tolerated, adoptive therapy with virus-specific cytotoxic T cells (CTL) can be utilized. Methods.?In this study, we used virus-specific CTLs to treat 8 patients suffering from severe viral infections after allogeneic HSCT. Using positive selection with HLA multimers and magnetic beads, we isolated CTLs from both frozen donor material as well as third-party donors within hours. Results.?At 90 days after CTL infusions 7 out of 8 patients were still living. CTLs infused from third-party donors were detected in 5 of 6 patients up to 76 days after infusion. No graft-versus-host disease associated with CTL infusions was observed. Conclusions.?Our separation approach offers a rapid alternative for adoptive CTL therapy if primary antiviral treatment strategies fail. Because no prolonged expansion steps are needed, this method may be used for early treatment of patients suffering from life-threatening infectious complications.     

Mechanism of loss of adenine nucleotides from mitochondria during myocardial ischemia.

We tested the hypothesis that loss of mitochondrial adenine nucleotides during myocardial ischemia is induced by the accumulation of inorganic phosphate (Pi) and a decrease in cytosolic ATP. In the isolated perfused rat heart, loss of mitochondrial adenine nucleotides (ATP + ADP + AMP) was preceded by the rise in tissue Pi and the loss of tissue ATP. After 30 min ischemia, the average rate of loss of mitochondrial adenine nucleotides was c. 1.5% of the initial pool/min. In isolated heart mitochondria, there are two pathways for adenine nucleotide release: a 'fast', phosphate-dependent pathway, which is inhibited by atractyloside; and a 'slow', phosphate-independent pathway, which is insensitive to atractyloside. Decreasing the pH from 7.4 to 6.5 significantly decreased the rate of release by the phosphate-dependent pathway (but not the phosphate-independent pathway). Analysis of release rates indicated that HPO4-2 is responsible for the phosphate-induced release; Vmax = 53.8% of the pool/per minute, Km = 7.5 mM. In vitro, extramitochondrial ATP inhibited adenine nucleotide release in the presence of Pi such that the rate of release was inversely proportional to the extramitochondrial [ATP]; extrapolation to zero ATP indicated a release rate of 2 to 3% of the pool/per minute, which is approximately equal to the rate of the 'slow' phosphate-independent pathway. Moreover, increasing the Pi concentration did not increase the rate of adenine nucleotide release in the presence of extramitochondrial ATP. Accumulation of mitochondrial adenine nucleotides was observed when the mitochondria were incubated in the presence of 4 mM or greater ATP. The results suggest that the rise in intracellular Pi during myocardial ischemia does not induce the loss of adenine nucleotides from the mitochondrial compartment, but rather that degradation of cytosolic ATP results in a slowing of ATP influx such that the rate of efflux (phosphate-independent) exceeds the rate of influx.     

Stable mixed donor–donor chimerism after double cord blood transplantation

Double cord blood transplantation (DCBT) has been used increasingly and has proven to be both safe and efficacious. In chimerism analysis, previous studies have indicated single unit predominance early after DCBT. In the present study, we evaluated the chimeric pattern in T-, B- and myeloid cells using PCR-based chimerism analysis in seven patients after DCBT: five patients had acute leukemia and two had lymphoma. Five patients received myeloablative conditioning and two patients were given reduced intensity conditioning. All patients received anti-thymocyte globulin (ATG) before DCBT. Three of the six evaluable patients showed donor–donor mixed chimerism in all cell lineages at 90 days after DCBT. Interestingly, two patients in long-term follow-up showed mixed donor chimerism in all cell lineages at 25 and 35 months after DCBT, respectively. Both patients are doing clinically well. Neither of the two developed GVHD after DCBT. In conclusion, in this study donor–donor mixed chimerism was common after high dose ATG and DCBT. Further studies are warranted concerning the immunological consequences of the phenomenon of donor–donor mixed chimerism after DCBT.     

Outcome of two Salvage Procedures for Posttraumatic Osteoarthritis of the Wrist: Arthrodesis or Proximal Row Carpectomy

Purpose: Presentation of the results of Tc-99m-sestamibi imaging in the pre-operative localization of parathyroid adenomas and the intra-operative localization of those lesions using a gamma detector (prospective study). Patients & methods: Eighteen consecutive patients aged 27-75 years with primary hyperparathyroidism (PHPT) underwent Tc-99m-sestamibi scanning 1-2 hours before the operation and the presence of a single adenoma was recognized. All our patients underwent bilateral neck exploration based on pre-operative scanning and intra-operative gamma detector guidance and the adenoma was detected in the positions shown by both methods.

Results: In 16 patients we found a single adenoma localized in the same position shown by pre-operative scanning, while the intra-operative method accurately revealed all abnormal glands. In one of the two patients where an inaccurate pre-operative localization technique had been carried out, we performed thyroid lobectomy (the adenoma proved to be intrathyroidal), while the other one had an adenoma which was not close to the site indicated by the pre-operative scintigraphy. Serum calcium reverted to normal within a few days postoperatively.

Conclusion: Patients with true-positive scans for single parathyroid adenoma could be eligible for minimally invasive operations since the abnormal gland is easily identified by the above-mentioned methods.     

Missed cancers on mammograms: causes and measures of prevention

Mammographically missed breast cancers remain a major medical and legal issue. In order to clarify causes and methods of the limitations, we present the experience of our Unit on this field. During the years 1999 and 2000, 319 breast cancer patients were admitted for surgical treatment to our Unit. Their files were reviewed in order to identify cases with mammography-related delayed diagnosis. Thirty-three cases of mammographically missed cancers were found (10.3%). The usual reasons for the delayed diagnoses were: retrospectively visible cancers, in benign looking lesions no further action was taken, and lesions with a rather malignant appearance were reported as benign. Missed cancers could be reduced by simple measures such as the full assessment of breast patients with clinical, radiologic, and cytologic-histologic evaluation, the double screening of mammograms, and improvement of the mammographic equipment and technique.