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Background and aim: Glucose-6-phosphatase catalytic subunit 3 (G6PC3) has been recently described as a metabolite repair enzyme involved in the disposal of the phosphorylated glucose analog 1,5-anhydroglucitol-6-phosphate (1,5AG6P). This function is especially relevant in neutrophils; indeed, G6PC3 deficiency leads to neutropenia as the accumulated metabolite 1,5AG6P inhibits the first step of glycolysis. Like neutrophils, tumoral metabolism also mainly relies on glycolysis, and we wondered if G6PC3 is expressed in uterine leiomyoma samples and if it can eventually have a role in the pathogenesis of these tumors. Understanding the complex pathophysiology of leiomyomas is a prerequisite to develop new therapeutic strategies. Methods: We used human uterine leiomyoma and matched myometrial samples. Immunohistochemistry and quantitative polymerase chain reaction (qPCR) were performed. Results: Immunohistochemical analysis has not evidenced appreciable differences between pathologic versus normal tissue samples. Indeed, qPCR analysis suggests a higher expression of G6PC3 in human uterine leiomyoma than in matched myometrial samples. Conclusion: A targeted therapeutic inhibition of G6PC3 in uterine leiomyoma samples is a potential strategy to slow down tumor growth.

The future approach of diagnostic imaging in urology follows the technological progress, which made the visualization of in vivo molecular processes possible. From anatomo-morphological diagnostic imaging and through functional imaging molecular radiology is reached. Based on molecular probes, imaging is aimed at assessing the in vivo molecular processes, their physiology and function at cellular level. The future imaging will investigate the complex tumor functioning as metabolism, aerobic glycolysis in particular, angiogenesis, cell proliferation, metastatic potential, hypoxia, apoptosis and receptors expressed by neoplastic cells. Methods for performing molecular radiology are CT, MRI, PET-CT, PET-MRI, SPECT and optical imaging. Molecular ultrasound combines technological advancement with targeted contrast media based on microbubbles, this allowing the selective registration of microbubble signal while that of stationary tissues is suppressed. An experimental study was carried out where the ultrasound molecular probe BR55 strictly bound to prostate tumor results in strong enhancement in the early phase after contrast, this contrast being maintained in the late phase. This late enhancement is markedly significant for the detection of prostatic cancer foci and to guide the biopsy sampling. The 124I-cG250 molecular antibody which is strictly linked to cellular carbonic anhydrase IX of clear cell renal carcinoma, allows the acquisition of diagnostic PET images of clear cell renal carcinoma without biopsy. This WG-250 (RENCAREX) antibody was used as a therapy in metastatic clear cell renal carcinoma. Future advancements and applications will result in early cancer diagnosis, personalized therapy that will be specific according to the molecular features of cancer and leading to the development of catheter--based multichannel molecular imaging devices for cystoscopy-based molecular imaging diagnosis and intervention. [ABSTRACT FROM AUTHOR]

Extracorporeal dialysis in uremic subjects produces erythrocyte alterations on energetic and redox metabolism. On this basis, we have tried to verify a fundamental parameter for the integrity of the red blood cell namely the glutathione content both in the oxidized and reduced form. Comparisons were made between two groups of subjects (similar in age, sex and number). One group consisted of uremic subjects undergoing dialysis and the other in healthy controls. As well as a slight increase in reduced glutathione (GSH), an accumulation of oxidized glutathione (GSSG) was found which, in postdialysis patients, reached values up to 3 times higher than in controls. This means a lowering in the ratio GSH/GSSG. There was also a decrease in total Mg(++)-ATPase activity, significantly found in erythrocyte ghosts of postdialysis patients. The hypothesis of a reduced efflux of GSSG as well as an increase in its formation speed (activation of glutathione peroxidase) is taken into consideration.

To study the effects of deep freezing on the energy metabolism of human spermatozoa, we investigated, by cytochemical quantitative methods, cytochrome oxidase and lactate dehydrogenase activities of fresh and frozen human spermatozoa during in vitro capacitation. Fresh and frozen human spermatozoa were incubated in Biggers, Whitten and Wittingham's medium supplemented with 15% heat-inactivated human serum. Both histoenzymological reactions can be quantitated and have been evaluated by microdensitometric method. The results indicate that human spermatozoa depend almost entirely on anaerobic glycolysis during in vitro capacitation and suggest that both aerobic and anaerobic metabolism in spermatozoa are only slightly impaired by freezing-thawing and storage.

Tissue location and biochemical aspects of the enolase, enzyme belonging to the glycolytic pathway, are presented. Embryological applications of the dimer gamma-gamma (Neuronal Specific Enolase) as a biological marker of the neuroectodermal derivatives is discussed. The authors stress the clinical importance of the NSE in the early detection of tumors.

The morphological and metabolic properties of red blood cells submitted to the procedure of loading by hypotonic hemolysis and isotonic resealing were compared with the controls. No appreciable differences could be detected concerning glycolytic ability, the amount of glucose metabolized in the hexose monophosphate pathway and the concentrations of glycolytic intermediates of ATP and of 2,3-DPG. Instead the concentration of reduced glutathione and the MCV were slightly reduced. These manipulated erythrocytes can be used as potential bioreactors or as carriers of exogenous substances.

In the present study we used a model of underperfusion or anoxia followed by reperfusion to assess the role of glycolysis by substituting pyruvate or mannitol for glucose as substrate. Hearts were removed from male Sprague-Dawley rats (250-400 g) and perfused by the technique of Langendorff. The perfusate was Krebs-Henseleit bicarbonate buffer gassed with 95% O2, 5% CO2 or with 95% N2, 5% CO2 mixture and containing substrates as can be seen in the figures. The mild ischemia was obtained by reducing the perfusion pressure by 70%, from 60-70 cm H2O to 10-20 cm H2O. The coronary flow was rapidly reduced to 0.8 +/- 0.03 ml/min within the first 5 minutes. After mild ischemia anaerobic glycolysis was accelerated because lactate production in ischemic hearts perfused with glucose (36.2 +/- 15.3 microM/g/min-1) was higher than in the ischemic hearts perfused with mannitol (6.8 +/- 1.9 microM/g/min-1). During mild ischemia or anoxia there was little difference in the rate of release of creatin-kinase for all the substrates tested, but major differences become apparent on reperfusion. In that period the highest values of CK release were found in mannitol perfused hearts, the lowest in glucose perfused hearts. These results suggest that the rate of glycolytic flux during mild ischemia or anoxia may prevent enzyme release. The beneficial effect of glucose has been observed also during reperfusion. In fact enzyme release was higher in hearts reperfused with glucose than with pyruvate. When pyruvate is the only exogenous substrate available for isolated oxigenated hearts, tissue levels of citric acid cycle intermediates are high and oxidation of these substrates can account for 100% of the oxygen consumption. Therefore we suppose that oxidation of noncarbohydrate substrates such as pyruvate in reperfusion is complicated by the high mitochondrial damage. As a consequence anaerobic glycolytic pathway may play a special role in the maintenance of the membrane integrity also in the early phases of reperfusion.

An updated and systematic account is given of cardiometabolic therapy by one who was among the first to investigate the biochemical pathology of the heart and the rational employment of biological substance in cardiological management. It is preceded by an explanation of the biochemical physiology of the myocardium and the metabolic changes associated with cardiac damage, and with heart failure in particular. The practical importance, effects and limits of metabolic cardiotherapy are assessed and its main fields of utilisation in current medical and cardiological practice are illustrated in the light of personal experience.

In the inherited ataxias, a heterogeneous group of relatively rare and progressive neurological disorders, abnormalities in pyruvate metabolism have been described. Pyruvate is involved in the glycolitic pathway as an important step, and utilized in the Krebs cycle, the main energy source in the brain. Furthermore, pyruvate and other intermediates in the Krebs cycle, can also serve as a precursors of amino acids for which a role as a neurotransmitter has been shown. The explanation of the basic biochemistry may serve as a basis for a more steady knowledge of the clinical and pathological findings of such diseases.

The authors, in this second part of the oxygen story, resolutely cross the borders of the biophysical field, and face the origins and becoming of life, the stages of which are synthesized in "casket" terms, unusual for surgeons: "protobionts", "procariots", "cyanobacteria", "chlorophyll", "caroteonides", "fermentation", "anaerobic glycolysis", "eucariots", "respiratory chain", "mitocondria". This is not an unconventional biological exercise, but the effort to give clinics a more legible ground, a sort of common denominator of the most different pathologies, and, among these ones, at the first place, just those of the specialistic branch, also less frequenter of biology, that is, surgery. This common denominator, the oxygen radicals represent the emerging apex of, like the peak of an iceberg, in fact, can be only investigated through an exasperated "philogenetic" recovering. Such process of "archaeology" seems to be the only suitable to supply us the cipher-key of the ambiguous, shifty character of oxygen, and entrust us with a cultural patrimony being unique as it is spendable in an immediate clinical future.

The picture, emerging from the experimental results on the physical association of multienzyme systems, is that the true physiological significance of the aggregated state can be understood only if it is correlated to the structural and functional integration of the cellular metabolic framework as a whole. The enzyme clusters exhibit two distinct functional properties. The first is the spatial translocation of intermediate substrates, the effect of which may be viewed as metabolic "channelling" or "vectorial catalysis" if the enzyme clusters are arrayed in some manner in the cell. The second is the coordinate regulation which represents an efficient and economical mean of controlling two or more functionally related enzymes. The common element to these two properties is the spatial character, which is potentially present in the function and the regulation of the intermediary metabolism. The biological systems, and metabolism in particular, exhibit both stability and variability; the latter sometimes assumes the character of periodicity. Whether the oscillations have a definite importance at the level of the intermediary metabolism itself, may well be questioned; the oscillatory faculties may rather serve as elements to be used in more complex functions of the biological systems. A thorough understanding of the role of clustered multienzyme systems and of the oscillatory phenomena in cellular metabolism demands a clearer physicochemical picture of the dynamic state of the living cell than we have at present. For this reason some of the generalizations derived from in vitro studies of single, isolated enzyme activities are not justified.