Effect of Two-Hour Daily Hemodialysis and Sham Dialysis on Breath Isoprene Exhalation

Background

Isoprene, a volatile hydrocarbon produced by the human organism, is currently being extensively investigated because the mechanisms underlying its endogenous origin are unknown and because experiments suggest it is toxic and cancerogenous. Previous reports of increases in breath isoprene concentrations during 4-hour, thrice-weekly hemodialysis, but not during continuous ambulatorial peritoneal dialysis, prompted us to assess the behavior of isoprene in another dialytic modality, i.e., short daily hemodialysis (short DHD). Furthermore, in order to determine whether removal of solutes and/or contact of blood with the dialytic membrane influenced the metabolism of isoprene, we performed a sham short hemodialysis session in a subgroup of 8 patients (sham short HD), i.e., with blood flowing through a dialyzer but without dialysate and ultrafiltration.

Methods

The present study evaluates the effects of a two-hour short DHD and a two-hour session of sham HD on isoprene breath levels, as determined by gas chromatography before, during and after sessions. Parallel analyses of ambient air and monitoring of blood pressure and heart rate were performed.

Results

Both short DHD and sham DHD induced an increase in breath isoprene exhalation in all patients without being associated with significant hemodynamic variations.

Conclusion

These findings suggest that the increase in breath isoprene after a session of hemodialysis is neither a reaction to mevalonate depletion nor to metabolic variations induced by the depurative effect, because these changes do not occur during sham HD. It is not related to hemodynamic changes because none were observed in this experimental model. The isoprene increase seems to be of metabolic origin and appears to be connected in some way with the extracorporeal circuit. These interesting findings provide a further impulse to study the biosynthetic pathways involved and to investigate the medical and biological significance of isoprene in humans. (Int J Artif Organs 2007; 30: 583–8)

[Epidemiology of chronic kidney disease in a population: residents in the territory of Umbria "Gubbio - Gualdese"]

The incidence of chronic kidney disease (CKD) has clearly increased in recent years. It is likely to be correlated with the aging population and with the growing association with vascular diseases. In Italy, there are different registers of dialysis and transplantation, providing an excellent means of monitoring patients in substitution treatment. On the contrary, few material is in our possession regarding CKD patients on conservative therapy. Therefore it lacks a necessary mean to implement mechanisms of prevention and programming for a disease that increasingly shows significant social - health consequences.

Abstract 1770: Metabolism and mechanism of action of fluorocyclopentenylcytosine (RX-3117)

Cytidine analogs play an important role in the treatment of various types of cancer, both solid tumors and leukemia. A novel cytidine analog fluorocyclopentenylcytosine (RX-3117) was characterized for its cytotoxic effects, its metabolism and its mechanism of action in a panel of 9 solid tumor and leukemic cell lines, as well as 6 variants resistant to gemcitabine, cytarabine and other pyrimidine analogs. Sensitivity in the parent cell lines after 72 hr exposure varied 75 fold with IC50 values from 0.4 to 30 µM RX-3117. The human equilibrative nucleoside transporter mediates transport of RX-3117, since its inhibition protected cells. Uridine and cytidine also protected cells against RX-3117, indicating that activation of RX-3117 is dependent on phosphorylation catalyzed by uridine-cytidine kinase (UCK), which was abundant in all tested cell lines, including the gemcitabine resistant variants. Deoxycytidine did not protect cells against RX-3117. RX-3117 was a very poor substrate for cytidine deaminase (66,000-fold less than gemcitabine). After its uptake in cells, RX-3117 was rapidly metabolised to its nucleotides with the triphosphate being the most prominent form (90% of all nucleotides), while synthesis of the nucleotides was highest in the most sensitive cell lines (U937 and A2780 cells) and lowest in the least sensitive cells (CCRF CEM cells). No difference in nucleotide formation was observed between the SW1573 and its gemcitabine resistant variant SW1573/G. In the AG6000 cells, the dCK- variant of A2780 and resistant to gemcitabine and RX-3117, a normal monophosphate level was found, but no di-and triphosphates were formed, explaining its resistance. Similarly incorporation of RX-3117 into RNA and DNA was higher in the sensitive A2780 and low in the insensitive SW1573 cells, with no difference between the gemcitabine sensitive and resistant variants. The effect of RX-3117 on synthesis of RNA and DNA was quite different; in the sensitive U937 cells 10 µM RX-3117 inhibited RNA synthesis 90%, while in A2780 and CCRF-CEM cells 100 µM RX-3117 was required for 90% inhibition of RNA synthesis. The effect on DNA synthesis was quite different. 1 µM RX-3117 completely inhibited DNA synthesis in the sensitive U937 cells, 80-90% inhibition was achieved with 10 µM in both CCRF CEM variants and with 100 µM in SW1573/G and AG6000, but in A2780 and SW1573 cells 100 µM only resulted in a partial or no inhibition, respectively. In conclusion, RX-3117 showed a completely different sensitivity profile compared to other cytidine analogs. Its uptake is transporter dependent; it is not activated by dCK, but by UCK. RX-3117 is incorporated into RNA and DNA; RX-3117 hardly affected RNA synthesis at IC50 values, but inhibited DNA synthesis. Its metabolism to nucleotides is related with its sensitivity, possibly because they directly inhibit the target presumably DNA methyltransferase.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1770. doi:1538-7445.AM2012-1770

Electroweak S and T parameters from a fixed point condition

We consider the standard model without the Higgs boson, where the Goldstone modes are described by a nonlinear sigma model. We study the renormalization group flow of the sigma model coupling f and of the electroweak parameters S and T. The condition that the couplings reach a fixed point at high energy leaves the low energy values of f and T arbitrary (to be determined experimentally) and fixes S to a value compatible with electroweak precision data.

[Historical Archives of Italian Nephrology. Diabetic nephropathy and insulin discovery: two parallel histories]

In 1936, Kimmelstiel and Wilson described the nodular glomerulosclerosis in patients with diabetes mellitus on insulin treatment. The nodular glomerulosclerosis is referred to as diabetic nephropathy. Fifteen years earlier insulin was discovered. This discovery at the University of Toronto (Canada) in 1921-22 by Banting, Macleod, Best and Collip was one of the most dramatic events in the history of the treatment of the disease. The impact of insulin was so sensational because of the incredible effect it had on diabetic patients. Those who first watched starved, sometimes comatose, diabetics receive insulin and return to life witnessed one of the genuine miracles of modern medicine. The discovery has became the "elixir of life" for millions of human beings around the world. Insulin had not emerged out of a vacuum but was the culmination of years of work by dozens of scientists in many countries. The Canadian scientists were the first to succeed in isolating insulin. Their work, however, was accurately constructed to confirm the ideas of earlier researchers, such as Murray, Paulesco, Allen, Minkowski, Derwitt, Zuelzer. These men, in addition to Banting, Macleod, Best and Collip, knew they were making medical history but paradoxically, with their "elixir of life" they allowed some complications of diabetes to emerge. Diabetic nephropathy was one of them. The struggle of the "Toronto quartet" for credit was inspired by man's desire to have a place in history, to have a sort of immortality open to him, an aspiration that is certainly legitimate. But perhaps the Canadian group misjudged both their situation and posterity's point of view. They probably failed to consider the unintentional effect of insulin treatment: diabetic nephropathy as a consequence of adding years to a diabetic's life.

Comparison between oscillometric and auscultatory methods of ambulatory blood pressure measurement in hemodialysis patients

INTRODUCTION

24-hour ambulatory blood pressure monitoring (ABPM) is commonly used in clinical and research practice. Different methods have been used in BP recording, cuff-oscillometric or Korotkoff sound, and validation studies during ABPM have been performed on general as well as hypertensive populations. Hemodialysis (HD) patients have a high percentage of complications, such as vascular diseases, and they are subject to hyperkinetic blood flows and abrupt body weight changes secondary to HD, which can invalidate BP recording. Therefore, we wanted to compare the 2 methods on an HD population.

PATIENTS AND METHODS

We performed 86 ABPMs on 44 patients (aged 60.8 +/- 17.2 years) by using a device capable of the simultaneous recording of oscillometric and auscultatory BP (A&D Takeda TM2421). The data obtained with the 2 different ABPM methods have been compared, and the differences between auscultatory and oscillometric determinations have been analyzed, as presented by Bland and Altman [1986].

RESULTS

The percentage of valid recordings was significantly higher with the oscillometric method than with the auscultatory method (93.6 +/- 11.3% vs. 71.7 +/- 17.04%, p < 0.001). 24-hour diastolic BP and night-time systolic BP were higher when recorded with the oscillometric method (DBP = 75.4 +/- 9.6 mmHg vs. 71.8 +/- 9.6 mmHg, p < 0.001, asleep SBP = 119.7+/-23.3 mmHg vs. 116.2 +/- 25.0 mmHg, p < 0.001), and the systolic night/day BP ratio was also higher(0.92 +/- 0.10vs.0.90 +/- 0.10, p < 0.001). Finally, the BP coefficient of variation ((SD/mean BP) x 100) was higher when auscultatory determinations were used (16.1 +/- 4.6 vs. 14.6 +/- 4.9). The limits of agreement between auscultatory and oscillometric BP determinations were for SBP = -6.44; 7.84 and for DBP = -3.66; 10.86.

CONCLUSIONS

Differences between 24-hour oscillometric and auscultatory ABPM were reported in HD patients: the diastolic 24-hour and asleep systolic BP values and the systolic night/day ratio obtained with the oscillometric method were significantly higher. The higher coefficient of variation reported with the auscultatory method and the wider limits of agreement suggest that the 2 methods do not fully coincide and, in our opinion, the oscillometric method is preferable, due to the higher number of 24-hour valid measurements.

A prospective study on mother-to-infant transmission of hepatitis C virus

To assess the rate of mother-to-infant transmission of hepatitis C virus (HCV) and to identify potential risk factors for transmission, we followed up (mean 22.4 months, range 1-7.5 years) a cohort of 291 babies born to anti-HCV-positive mothers, 40 of whom were also HIV coinfected. Seventeen (5.8%) babies acquired HCV infection, but none became icteric. All babies developed chronic HCV infection with 16 babies showing elevated levels of ALT. The rate of transmission was higher in babies born to mothers coinfected with HIV than in those born to mothers with HCV alone (22.5 vs. 3.2%, p < 0.0001). No association was seen between a specific maternal HCV genotype and an increased risk of neonatal infection. The median level of HCV-RNA was higher in mothers who transmitted infection than in those who did not, although the ranges overlapped. In this study, maternal history of chronic liver disease, mode of delivery and type of feeding were not predictive of HCV infection.

Morbidity and mortality due to liver disease in children undergoing allogeneic bone marrow transplantation: a 10-year prospective study

We have conducted a long-term prospective study of children undergoing bone marrow transplantation (BMT) to assess morbidity and mortality for liver disease. One hundred eleven consecutive children were enrolled between June 1985 and June 1995 and were followed-up for a median of 5.5 years after BMT. Before transplant 48/111 children (43%) had abnormal alanine aminotransferase (ALT), none were HBsAg+ and 4/111 were anti-HCV+. After BMT 4/111 patients (3. 6%) died of liver failure. No relationship was found between pretransplant hepatitis B (HBV) or C (HCV) infection or elevated transaminases and development of severe liver damage. Eighty-two out of one hundred and eleven patients (74%) had abnormalities of ALT after BMT, transient (n = 54) or persistent (n = 28). None developed clinical signs or symptoms of end stage liver disease or of cirrhosis during follow-up. No significant difference in prevalence of liver disease, was found between children with normal or abnormal ALT at BMT (relative risk [RR] = 1.04). HCV infection could be implicated in the etiology of chronic liver disease in 14/28 patients; 2 other patients were found infected by HBV alone (1 case) or combined with HCV (1 case). In the remaining 12 the etiology of chronic liver disease could not be defined. Posttransplant hepatitis B occurred in 4/111 children (3.6%), including a recipient from a donor who had been previously vaccinated against HBV, while no patient who had been vaccinated developed hepatitis B. The rate of posttransplant seroconversion to anti-HCV was 15%.

G-CSF stimulated donor granulocyte collections for prophylaxis and therapy of neutropenic sepsis

BACKGROUND

The administration of granulocyte colony-stimulating factor (G-CSF) increases the granulocyte count in normal donors and enables the collection of large numbers of mature myeloid cells by leukapheresis. This has potential value in the treatment of sepsis unresponsive to antibiotics in patients with severe neutropenia.

AIM

To evaluate the tolerability of granulocyte collections in normal donors receiving G-CSF, the optimal method of collection and the clinical factors influencing the efficacy of granulocyte infusions.

METHODS

Analysis of the outcome of 55 granulocyte collections from 26 donors for progressive bacterial or fungal sepsis in neutropenic patients (n = 8) or as prophylaxis in patients with recent fungal infections undergoing allogeneic bone marrow transplantation (BMT) (n = 3).

RESULTS

G-CSF was well tolerated in most donors. Fatigue occurred commonly after the second collection. The median WCC per 200-220 mL bag was 351 x 10(9)/L. Collections were optimised with the use of a sedimenting agent (dextran) and a deepened interface setting on the cell separator. There was only a weak correlation between the number of granulocytes infused and the increment in the patient, but levels were usually maintained > or = 0.5 x 10(9)/L for the next 24 hours. The infusions were successful in three septic patients without multi-organ dysfunction and prophylactically, in two patients with localised fungal infections undergoing MBT. The infusions were not beneficial in patients with septicaemia and established organ dysfunction or with extensive pulmonary aspergillosis.

CONCLUSIONS

G-CSF mobilised granulocyte collections are feasible and the preliminary evidence suggests that the infusion of these cells may be useful early in the prophylaxis or treatment of severe neutropenic sepsis.

Health care for the uninsured in Duluth

Providing health care for Minnesota's uninsured population continues to be both a clinical and political challenge. Between October 1, 1991, and September 30, 1993, 1,260 previously uninsured people received charity health care in Duluth. No one was excluded because of pre-existing conditions. Their utilization of services and associated costs can help project the health care needs and costs of care for uninsured Minnesotans. This group of uninsured people used a different mix of health care services compared with insured Minnesotans, and their total costs (including prescriptions) were about 15% greater. A large proportion of these uninsured Minnesotans had chronic health conditions and a "pent-up need" for services and medications. This experience demonstrated that it is possible to administer a limited benefits plan in coordination with existing public and private resources.

Mother-to-infant transmission of hepatitis C virus. Lombardy Study Group on Vertical HCV Transmission

To assess the risk of mother-to-infant transmission of hepatitis C virus (HCV), we followed up 116 babies of anti-HCV positive mothers, of whom 22 were coinfected with HIV and 94 had HCV alone. None of the babies whose mothers had HCV alone acquired HCV, while 8 babies (36%; p < 0.001) of mothers co-infected with HIV acquired HCV (5 babies) or HCV and HIV (3). There was no association between any specific maternal HCV genotype and enhanced risk of neonatal infection. HCV-RNA levels were significantly higher (p < 0.05) in mothers with HIV coinfection than in those with HCV alone. These data indicate that maternal HIV status correlates with enhanced level of viraemia which favours neonatal infection.

[The hadron therapy project]

The neologism "hadrontherapy" means radiotherapy with hadrons, which are the particles constituted by quarks, such as protons, neutrons and ions. The theoretical considerations about the clinical advantages this treatment modality can yield and the results obtained at the centers where it has already been used justify the proposal to project a center of this kind also in our Country. To this purpose, two of the authors of this paper (U. Amaldi, G. Tosi) founded the TERA Group formed by physicists, engineers and radiotherapists who work in close collaboration on a feasibility study for a hadrontherapy facility. The first aim of the Hadrontherapy Project is to design a center equipped with a synchrotron which, at the beginning, will accelerate negative hydrogen ions (H-) which will first produce 70-250 MeV proton beams and, then accelerate light ions (up to 16O) to 430 MeV/amu. This accelerator will serve four or five treatment rooms where patients can be irradiated simultaneously. Two rooms will be equipped with a fixed horizontal beam for the treatment of eye, head and neck tumors; the others will be equipped with rotating gantries to administer, in any clinical situation, really adequate treatment. Such a unit, when enough experience is fained, will allow at least 1000 patients to be treated yearly. The synchrotron injector will be designed so as to allow, parallel to the radiotherapy activities, other applications of medical and biological interest such as: the production of radioisotopes for diagnostic use (especially positron emitters), the analysis of trace elements through the PIXE technique and the production of thermal and epithermal neutrons for boron neutron capture therapy.

[Radiographic examination of the pelvis in patients under periodic hemodialysis for terminal uremia]

Significant signs of uremic osteodystrophy were found at Rx examination of the pelvis in 29 out of 72 uremic patients (40%) undergoing maintenance hemodialysis. It is therefore thought that Rx of the pelvis, although it is more significant for some signs (brown tumors, alterations of the trabecular structure, enlargement of Ward's triangle) than for others, such as subperiosteal resorption, should not be neglected in these patients.

[The parenteral administration of essential amino acids in patients on periodic hemodialysis treatment. A pilot study]

In an attempt to improve the nutritional status of seven hemodialysed patients, 500 ml of a 5.5% nephrological essential amino acid solution (EAA) were administered during each dialysis session for 2 months. At the end of this treatment, a significant increase in albuminemia was found (p < 0.05). These results are an encouragement to continue this therapy, especially if it is kept in mind that the half-life of albumin is much shorter than the period of EAA administration.

[Surveillance by skeletal radiography of patients under hemodialysis. Radiographic examination of the vertebral column]

The authors describe damage to the spine observed by x-ray in patients on maintenance hemodialysis. They stress the importance of including x-ray examination of the spine among the routine checks performed in these patients.

Hepatitis C virus and porphyria cutanea tarda: evidence of a strong association

Porphyria cutanea tarda in human beings is believed to be due to reduced hepatic uroporphyrinogen decarboxylase activity. However, extrinsic factors such as alcohol abuse and drug intake are required for clinical manifestation of the disease. In addition to typical cutaneous lesions, patients with porphyria cutanea tarda usually have chronic liver disease and moderate iron overload. Of 74 Italian patients with porphyria cutanea tarda, hepatitis C virus antibodies were detected in 76% by enzyme-linked immunoassay and in 82% by recombinant immunoblot assay. Viral genome, studied with nested polymerase chain reaction, was found in the sera of 49 subjects--47 positive and 2 indeterminate on recombinant immunoblot assay. Five percent of the patients were HBsAg-positive, and about 40% had had past hepatitis B contacts. Alcohol abuse was present in 38%. Liver biopsies performed in 42 patients showed chronic persistent hepatitis in 7 patients, chronic active hepatitis in 22 patients, fibrosis in three patients and cirrhosis in 10 patients. Hepatitis C virus antibody was detected in 100% of patients with chronic active hepatitis and in about 80% of all other groups. Alcohol abuse was more frequent in patients with cirrhosis (80%) than in the other groups. In Italian patients with porphyria cutanea tarda, the prevalence of hepatitis C virus infection was very high, comparable to that in non-A, non-B hepatitis and high-risk patient groups. Hepatitis C virus is probably the main pathogenetic factor of the liver disease of patients with porphyria cutanea tarda.

Liver damage in Italian patients with hereditary hemochromatosis is highly influenced by hepatitis B and C virus infection

We evaluated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in 78 Italian patients with hereditary hemochromatosis as well as the relation between HCV antibody (anti-HCV) status, hepatitis B surface antigen (HBsAg) and liver histology. None of the patients had been transfused or ever consumed more than 60 g of alcohol per day. Eighteen showed histological signs of chronic hepatitis, active cirrhosis was present in 12, chronic active hepatitis in 4 and chronic persistent hepatitis in 2. Liver fibrosis or cirrhosis without inflammatory activity was observed in 31 subjects, whereas liver histology was normal except for iron overload in 18. The prevalence of HBsAg in the whole series was 5% and of anti-HCV was 20.5%. The prevalence of HBsAg and anti-HCV was significantly higher in the chronic hepatitis group than in the fibrosis/cirrhosis (p = 0.01) and the normal groups (p < 0.01). Fourteen of 18 hereditary hemochromatosis patients with chronic hepatitis were HBsAg (4) or anti-HCV (10) positive and all the latter subgroup had HCV-RNA in their serum as shown by the polymerase chain reaction. Although most of the patients with associated chronic hepatitis had cirrhosis, their serum ferritin levels and amount of mobilizable iron were significantly lower than those of the fibrosis/cirrhosis group (p < 0.01). This indicates that hepatitis viral infection acts synergistically with iron in accelerating the development of liver damage.

Hepatitis C virus infection in patients with idiopathic hemochromatosis (IH) and porphyria cutanea tarda (PCT)

The prevalence of HCV antibodies in IH and PCT patients was examined. It was found that both groups are characterized by increased incidence of HCV infection. These results suggest a possible connection between HCV and iron overload.

[Serologic study on the prevalence of HIV, HBV infection and on the false positive reaction of VDRL at a prison]

Prisoners are considered to be a high risk population for HIV and HBV infection. Aim of this study was to determine the prevalence of HIV, HBV infection and of the VDRL false positivity by performing screening tests in 496 prisoners of Monza in 1987. About a third of prisoners was HIV infected (with a high prevalence in drug addicts) and about a half had a contact with HBV virus. We observed a very common association between HIV and HBV infections. About ten per cent of HIV infected presented a false positivity for VDRL while one per cent of not infected did. Our data show that in Italian prison HIV and HBV infections are spreadly diffused. False positivity for VDRL may be due not only to drug addiction but also to the immunological variations connected with AIDS.