Substance P--a potent risk factor in childhood lymphoblastic leukaemia

The study focused on determining the expression of substance P (SP) in neoplastic bone marrow cells in childhood acute lymphoblastic leukaemia (ALL) in terms of its mRNA and the level of protein production. An attempt has also been made to demonstrate a correlation of SP with leukaemia risk factors and treatment failure. The study group comprised 120 children treated for ALL. Expression of SP was examined by in situ hybridisation with a 5'-biotinylated probe and by immunocytochemistry with specific anti-human SP antibody. Out of 80 patients with common ALL, the expression of SP was demonstrated in 33 cases (41.2%). In the group of 24 children with pre-B ALL, the presence of SP was noted in six cases (25.0%). Of 16 patients with T-cell leukaemia, SP expression was demonstrated in 13 cases (81.2%). The percentage of immunopositive cells in the SP-positive cases ranged from 79.8 to 97.3. Treatment failure in the children with ALL was closely related to the expression of SP observed at the beginning of treatment. The results showed a connection between the presence of SP-positive blasts and leukaemia relapse. This may indicate that SP expression, involved in the proliferation of the tumour cells, may represent a novel risk factor in ALL.

Pituitary adenylate cyclase-activating polypeptide-immunoreactive (PACAP-IR) nerve fibers in the pig pineal gland

The present study demonstrates the occurrence of PACAP-immunoreactive (PACAP-IR) nerve fibers in different compartments of the pig pineal gland, including glandular capsule (where they form a very dense network) and subependymal tissue close to the pineal recess (moderate to dense meshwork of varicose fibers). Furthermore, several varicose fibers penetrate from the capsule into the connective tissue septa and then into the parenchyma, where they form unequally distributed, fine network and, in some cases, basket-like structures around pinealocytes. Some of the PACAP-IR nerve fibers, observed both in the habenular and posterior epithalamic areas, extend to the pineal gland. PACAP-IR cells could be demonstrated neither in the pineal gland, nor in epithalamic areas.

Distribution of NADPH-diaphorase activity in the pineal gland of the Turkey

NADPH-diaphorase activity was histochemically demonstrated in the nerve fibers, neuronal-like cell bodies and in the endothelial cells of the vasculature in the pineal gland of the turkey. The nerve fibers were localized in the choroid plexus, connecting the pineal gland with the diencephalon as well as inside the pineal gland, where they formed basket-like structures around the pineal follicles. A group of neuronal-like cell bodies was observed in the proximal part of the gland. The positive staining was not observed in the pinealocytes of rudimentary-photoreceptor type and in the supporting cells.

Specific distribution pattern of nerve fibers containing catecholamine-synthesizing enzymes, neuropeptide Y (NPY) and C-terminal flanking peptide of NPY (CPON) in the pineal gland of the chinchilla (Chinchilla laniger)--an immunohistochemical study

The sympathetic nerve fibers originating from the superior cervical ganglia and supplying the pineal gland play the most important role in the control of the pineal activity in mammals. NPY and CPON are also present in the majority of the pinealopetal sympathetic neurons. In this study, immunohistochemical techniques were used to demonstrate the existence and coexistence of tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) as well as NPY and CPON in the nerve fibers supplying the chinchilla pineal gland. Ten two-year-old female chinchillas housed in natural light conditions were used in the study. The pineals were fixed by perfusion. ABC immunohistochemical technique and immunofluorescence labelling method were employed. TH-immunoreactive (TH-IR) varicose nerve fibers were observed in the pineal gland as well as in the posterior commissural area. Within the chinchilla pineal gland, TH-IR nerve fibers were located in the capsule and connective tissue septa. Numerous varicose TH-IR branches penetrated into the parenchyma and formed a network showing the highest density in the proximal region of the gland. In the central and distal parts of the pineal parenchyma, a subtle network, composed of thin varicose nerve branches, was observed. Double immunostaining revealed that the majority of TH-IR nerve fibers was positive for DbetaH or NPY. TH- and DbetaH-positive neuron-like cells were observed in the proximal region of the gland. The pattern of pineal innervation immunoreactive to CPON was similar to the innervation containing NPY, TH and DbetaH. The chinchilla intrapineal innervation containing TH, DbetaH, NPY and CPON is characterized by the higher density in the proximal part of the gland than in the middle and distal ones. The specific feature of the chinchilla pineal is also the presence of single TH/DbetaH-immunoreactive neuron-like cells in the proximal part of the gland.

Demonstration of nerve fibers immunoreactive to peptide N-terminal histidine C-terminal isoleucine (PHI) and vasoactive intestinal peptide (VIP) in the pig pineal gland

The pineal functions are modulated by some neuropeptides including PHI and VIP. The presence of PHI-immunoreactive and VIP-immunoreactive nerve fibers in the pineal gland has been shown in several mammalian species. Both peptides influence the pineal serotonin N-acetyltransferase activity and melatonin synthesis. The aim of the present study was to examine the localization of PHI- and VIP-immunoreactive nerve fibers in the pig pineal gland. Four three-month old female pigs housed in natural light conditions, with free access to food and water, were used in the study. The pineals were fixed by perfusion with 4% paraformaldehyde in 0.1 M phosphate buffer. An immunohistochemical ABC streptavidin-biotin-complex method was used for the demonstration of PHI and VIP. PHI- and VIP-immunopositive nerve fibers were found in the pineal gland as well as in the habenular and posterior commissural areas. In the pineal gland, the density of PHI-immunoreactive nerve fibers was considerably higher than that of the fibers containing VIP. PHI- and VIP-immunopositive nerve fibers were more abundant in the cortical than in the medullary part of the gland. The nerve fibers formed bundles in the pineal capsule, from where they penetrated to the connective tissue septa and formed a dense meshwork surrounding blood vessels. In the parenchyma, PHI- and VIP-immunoreactive nerve terminals created baskets around clusters of pinealocytes. No PHI- or VIP-immunopositive cells were found in the pig pineal gland.

Influence of 4-day long treatment with vasoactive intestinal peptide on ultrastructure and function of the rat pinealocytes in organ culture

Vasoactive intestinal peptide (VIP) is one of neuropeptides involved in the regulation of the pineal gland function. The acute treatment of rat pinealocytes with VIP caused changes in their biochemical parameters. The present study concerns the effects of the chronic treatment with VIP on ultrastructure and function of the rat pinealocytes in organ culture. The pineals of adult male rats were assigned to one of three groups and placed in organ culture for four consecutive days. The pineals of the first group were incubated in the control medium, the pineals of the second group--12 hrs in control medium and 12 hrs in medium with 1 microM VIP (between 20.00 and 8.00) during each day, the pineals of the third group--24 hrs per day in medium with 1 microM VIP. The melatonin concentration was measured using RIA and activity of enzymes using radiochemical methods. Point count method was used in quantitative ultrastructural analysis. Both modes of chronic treatment with VIP increased significantly the level of melatonin secretion during four days of the culture and the content of this hormone in the pineal explants at the end of the experiment. Treatment with the neuropeptide for 12 hrs and 24 hrs per day elevated also the activity of arylalkylamine N-acetyltransferase and hydroxyindole-O-methyltransferase. On the other hand, VIP had no effect on the activity of arylamine-N-acetyltransferase. VIP increased the relative volume of rough endoplasmic reticulum, Golgi apparatus and mitochondria and did not influence the relative volume of lysosomes and lipid droplets as well as the numerical density of dense core vesicles in the examined rat pinealocytes. The obtained results indicate stimulatory effect of chronic treatment with VIP on the synthesis and secretion of melatonin in the rat pinealocytes in vitro. The results of morphological study are in agreement with the obtained biochemical data and point to the increase in secretory and metabolic activity of the rat pinealocytes in response to VIP.

Carvedilol does not modulate moderate exercise-induced hyperkalemia in hemodialysis patients

BACKGROUND AND AIM

Non-selective beta-adrenergic blockers may cause hyperkalemia in patients with end-stage renal failure. In contrast, alpha-adrenergic blockade has been found to decrease the hyperkalemic effect of physical exercise in healthy subjects, although we were unable to confirm this effect in hemodialysis patients. In a crossover design, we studied the effect of carvedilol, a non-selective beta-adrenergic blocker with an additional alpha1-blocking activity, on exercise-induced hyperkalemia in 17 anuric hemodialysis patients.

METHODS

All subjects were given either carvedilol (25 mg/day) or placebo for 2 weeks in a random order with a 2-week wash-out period. At the end of each treatment period they underwent a 30-minute exercise test on a bicycle ergometer with a fixed load of 20 W.

RESULTS

The treatment with carvedilol caused a significant decrease in blood pressure. Serum potassium before exercise tests was similar (5.37 +/- 0.2 and 5.24 +/- 0.2 mmol/l on carvedilol and placebo, respectively; mean +/- SE). During the exercise, serum potassium increased significantly (p < 0.001 in both tests) and subsequently decreased during 30 minutes of recovery (p < 0.05). The mean rate of potassium increment during the exercise was similar (23.3 +/- 3.3 micromol/l/min on carvedilol and 20.0 +/- 3.6 micromol/l/min on placebo). During recovery, the mean rate of potassium decrement was 5.0 +/- 3.0 micromol/l/min and 6.7 +/- 2.7 micromol/l/min, respectively. Serum sodium, ionized calcium, insulin and plasma renin activity were similar before the exercise tests and did not change during the exercise.

CONCLUSION

Carvedilol does not enhance the hyperkalemic effect of moderate physical exercise in anuric hemodialysis patients.

Discontinuation of potent antiretroviral therapy: predictive value of and impact on CD4 cell counts and HIV RNA levels

OBJECTIVE

To characterize predictors and consequences of discontinuing antiretroviral therapy (ART) in terms of CD4 cell count, HIV RNA, and reported side-effects in a large cohort of HIV-infected women.

DESIGN

Cohort study.

METHODS

A total of 1058 HIV-infected women initiated potent ART before September 1999. For each 6 month period after October 1996 we determined the proportion of potent ART users who downshifted to non-potent ART and who discontinued all ART. We examined the role of CD4 cell count and HIV RNA with regard to ART discontinuation.

RESULTS

Between October 1996 and September 1999, 1058 individuals contributed 3362 visits at which potent ART was reported in the previous 6 months. Overall rates of 6 month downshifting and discontinuation were 10.0% and 6.7%. The proportion of individuals discontinuing all ART increased from 2.9% in late 1996 to 9.1% in mid 1999 (P < 0.001). Individuals with high HIV RNA levels were more likely to discontinue (P < 0.05). Compared to those who continued on potent ART, individuals who discontinued experienced large declines (P < 0.001) in CD4 cell counts and were more than three times more likely (P < 0.001) to experience HIV RNA increases. However, over one-third of those discontinuing ART reported side-effects and this subset had smaller CD4 cell count declines as compared to discontinuers not reporting side-effects (P = 0.147).

CONCLUSIONS

In a large cohort of HIV-infected women, an increasing proportion of potent ART users discontinued ART over 3 years. Higher HIV RNA levels predicted discontinuation. Immediate immunological/virological deleterious consequences were observed. Side-effects were the most common reason for discontinuation and CD4 cell count declines were larger among those who did not cite side-effects as the reason for discontinuation.

Managing impossible missions: ethical quandaries and ethical solutions

Healthcare financial managers are confronted daily with ethical and practical conflicts, particularly with regard to meeting the conflicting and unduly restrictive laws and regulations with which their organizations must comply. Sometimes the right course of action is not clear, as an examination of the 72-hour rule, safe harbor provisions, and legal interpretations of the False Claims Act reveals. Healthcare financial managers have an ethical duty, based on healthcare codes of ethics and ethical theories, to oppose laws and regulations that put their organizations in untenable legal and ethical situations.

[Congenital hyperammonemia in neonates treated with hemodiafiltration]

Inborn defects of urea cycle often results in life-threatening hyperammonemia in neonates. The initial therapy of this disease comprises administration of benzoate sodium, arginine, lactulose, neomycin, and restrictive alimentation based on carbohydrates. Renal replacement therapy for ammonia removal should be considered for the most severe cases. We present a case report of two neonates with very rare inborn urea cycle disorders--deficiency of argininosuccinate lyase and carbamyl-phosphate synthetase, treated with spontaneous arterio-venous haemodiafiltration.

[Platelet activation in relapse idiopathic nephrotic syndrome in children]

The role that platelets play in pathogenesis and thromboembolic complications of the idiopathic nephrotic syndrome (INS) in children still remains unclear. The aim of the study was to analyse of platelet activation in whole blood during first 8 weeks of ins. Study group comprised 24 children with 34 relapses of INS by ISKDC (group A). Obtained results were compared to 16 healthy children (group B). We assessed activation by the count of platelet aggregates, microparticles and surface expression of selected markers--CD62P (P-selectin), CD42b (part of von Willebrand factor receptor) at the onset INS, after 2 weeks of therapy. We found the increased counts of platelet aggregates and microparticles at the onset of INS with a systematic decrease in following 2 weeks. Furthermore, expression of CD42b was significantly lower at the beginning of therapy. There were no clear correlation between markers of activation and biochemical parameters in the study group. According to these findings we conclude that increased activation of blood platelets is an independent risk factor of thromboembolic complication in the early stages of relapse of INS. The role of platelets in pathogenesis or induction of ins relapse remains the matter for further investigation.

Exposure of hepatitis C virus (HCV) RNA-positive recipients to HCV RNA-positive blood donors results in rapid predominance of a single donor strain and exclusion and/or suppression of the recipient strain

We have analyzed three cases of hepatitis C virus (HCV)-infected recipients who received blood from HCV-infected donors. Two recipients were exposed to two different HCV RNA-positive donors, and one was exposed to a single donor. All parental genomes from the actual infecting units of blood and the recipients were defined, and their presence in the follow-up serum samples was determined using sensitive strain-specific assays. The strain from one of the donors was found to predominate in all recipients' serum samples collected throughout the follow-up period of 10 to 30 months. In two recipients exposed to two infected donors, the strain from the second donor was occasionally found at very low level. However, the original recipients' strains were not detected. Our observations show that HCV-infected individuals can be superinfected with different strains, and this event may lead to eradication or suppression of the original infecting strain. Furthermore, our findings demonstrate that simultaneous exposure to multiple HCV strains may result in concomitant infection by more than one strain, although a single strain could rapidly establish its dominance. The results of the present study suggest the existence of competition among infecting HCV strains which determines the ultimate outcome of multiple HCV exposure.

Exposure of hepatitis C virus-negative recipients to > or =2 infected blood donors

This study analyzed 4 cases of hepatitis C virus (HCV)-naive transfusion recipients who developed hepatitis after receiving blood from >1 HCV-infected donor. One recipient was exposed to 4 donors, 2 were exposed to 3 donors, and 1 was exposed to 2 donors. For 3 recipients, the strain from 1 of the donors predominated in all follow-up samples collected for 8-40 months. For 2 recipients, the strain from the second donor was occasionally detectable with sensitive strain-specific assays. For the fourth recipient, the initially dominant strain was later supplanted by a strain from the other donor. Simultaneous exposure to multiple HCV strains may result in concomitant infection by >1 strain, although a single strain rapidly establishes its dominance. These observations are compatible with the presence of competition among infecting HCV strains that results in the dominance of 1 strain and competitive exclusion or suppression of other strains.

Hormonal regulation of appetite and body mass in patients with advanced prostate cancer treated with combined androgen blockade

Cachexia is rarely observed in patients with advanced prostate cancer treated with combined androgen blockade. Androgens play an important role in the regulation of body mass composition and influence the secretion of leptin, the appetite regulating hormone. The aim of the study was to assess the influence of a combined treatment with nonsteroidal antiandrogen and LH-RH analogue on the hormonal regulation of appetite and changes in body mass in patients with advanced prostate cancer (Whitmore-Jewett stage D1 or D2). Eighteen patients with prostate cancer and 17 healthy subjects matched for age and body mass index were included. In all patients serum concentrations of leptin, neuropeptide Y (NPY), insulin, testosterone and estradiol were measured before and after four and twelve weeks of androgen blockade. Pretreatment serum leptin levels were similar in patients with prostate cancer and in the controls. In a multiple regression analysis only body mass index and testosterone significantly contributed to the variation of plasma leptin. During the treatment body mass and plasma leptin significantly increased while NPY decreased. The change of plasma NPY was significant only after 4 weeks of therapy. This study shows that the afferent regulation of leptin secretion is unchanged in advanced prostate cancer. Androgen ablation significantly increases body mass and influences secretion of appetite regulating hormones. Testosterone appears to play a significant role in the regulation of leptin secretion.

Selection by indication of potent antiretroviral therapy use in a large cohort of women infected with human immunodeficiency virus

To characterize selection factors related to therapy initiation, the authors investigated the extent to which key markers of human immunodeficiency virus (HIV) disease severity were associated with initiation of potent antiretroviral therapy (ART). Logistic regression was used to determine the effects of CD4+ cell count and HIV RNA level on potent ART initiation during 6-month periods among 2,059 HIV-infected US women enrolled in the Women's Interagency HIV Study. Low CD4+ counts and high HIV RNA levels were significantly (p < 0.05) associated with initiation of potent ART. During all periods between April 1996 and March 1998, CD4+ counts were more strongly associated with potent ART initiation than HIV RNA levels were; however, during the last period, both were associated (odds ratio per 100 CD4+-count decrease = 1.17, p < 0.01; odds ratio per 1 log10 increase in HIV RNA level = 1.48, p < 0.05). For a CD4+ count of 500 cells/ml and an HIV RNA level of 5,000 copies/ml, the probability of potent ART initiation increased from 0.5% to 16.8% between October 1995-March 1996 and October 1997-March 1998, suggesting earlier initiation of potent ART. Given the documented occurrence of confounding by indication, prospectively collected, time-dependent data on markers of disease progression and therapy use should be considered when making population-level comparisons before and after introduction of potent ART.

Detection and quantitation of human immunodeficiency virus type 1 in the female genital tract. The Division of AIDS Treatment Research Initiative 009 Study Group

Human immunodeficiency virus type 1 (HIV-1) was detected in the genital tracts of 59% of 225 women by RNA PCR and in 7% of the women by culture. In a comparison of two sampling methods, endocervical swabs were more sensitive than cervicovaginal lavage for HIV-1 RNA detection by PCR but not by culture and their sensitivity was independent of the concentration of HIV-1 RNA.

Comparison of two amplification technologies for detection and quantitation of human immunodeficiency virus type 1 RNA in the female genital tract. Division of AIDS Treatment Research Initiative 009 Study Team

Human immunodeficiency virus type 1 (HIV-1) RNA levels in female genital tract and peripheral blood samples were compared using two commercial amplification technologies: the Roche AMPLICOR HIV-1 MONITOR test and either the Organon Teknika nucleic acid sequence-based amplification (NASBA-QT) assay or the NucliSens assay. Estimates of HIV-1 RNA copy number were derived from internal kit standards and analyzed unadjusted and adjusted to a common set of external standards. We found a discordance rate of approximately 18% between the two technologies for the detection of HIV-1 in either the genital tract or peripheral blood samples. Detection discordance was not consistent among specimens or among women. There were no significant differences in adjusted or unadjusted estimates of HIV-1 RNA copy number in the genital tract samples using the AMPLICOR HIV-1 MONITOR test and either the NASBA-QT assay or the NucliSens assay. In addition, the estimated HIV-1 RNA copy number in peripheral blood samples did not differ when tested with the NucliSens assay and the AMPLICOR HIV-1 MONITOR test using kit standards. However, there was a significant difference in estimated RNA copy number between the NASBA-QT assay and the AMPLICOR HIV-1 MONITOR test for internal kit standards, which, as we have previously shown, was eliminated after adjustment with the external standards. Our results suggest that the Roche and Organon Teknika assays are equivalent for quantifying HIV-1 RNA in female genital tract specimens, although variation in detection does exist.

Detection of active hepatitis C virus and hepatitis G virus/GB virus C replication in bone marrow in human subjects

We have analyzed the presence of hepatitis C virus (HCV) and hepatitis G virus (HGV) sequences in bone marrow and serum samples from 48 patients of a hematologic outpatient clinic. HCV RNA was detected in 18 (38%) and 15 (31%) and HGV RNA was detected in 6 (13%) and 9 (19%) of serum and bone marrow samples, respectively. In 3 patients, HGV RNA was detectable in bone marrow but not in the serum; 2 of these patients were negative for the presence of specific antibodies. Using a highly strand-specific Tth-based reverse transcriptase-polymerase chain reaction (RT-PCR), the presence of HCV RNA and HGV RNA negative strand was demonstrated in 4 and 5 bone marrow samples, respectively. Our study shows that HCV and HGV can replicate in bone marrow; in the case of HGV, analysis of serum may underestimate the true prevalence of infection. (Blood. 2000;95:3986-3989)

Serum albumin as a predictor of survival in HIV-infected women in the Women's Interagency HIV study

BACKGROUND

The level of serum albumin is associated with mortality in a wide variety of chronic diseases. However, few studies have examined the relationship between serum albumin and survival in HIV-1 infection.

OBJECTIVES

To determine whether the serum albumin level is associated with survival in HIV-1 infected women.

DESIGN

Prospective cohort study. Patients were interviewed and examined at 6 month intervals.

SETTING

A North American multi-institutional cohort of HIV-infected women from five geographical areas.

PARTICIPANTS

A total of 2056 HIV-infected women at various stages of disease.

MEASUREMENTS

Mortality during the first 3 years of follow-up. The relative risk of death by serum albumin level was estimated using a proportional hazards ratio adjusted for CD4 cell count, HIV-1-RNA level and other relevant covariates.

RESULT

Three year mortality for women in the lowest serum albumin category (< 35 g/l) was 48% compared with 11% in the highest category (> or = 42 g/l; P < 0.001). The adjusted relative hazard (RH) of death was 3.1 times greater for those in the lowest albumin category (P < 0.01). The excess risk associated with lower serum albumin levels remained when subjects with moderate to severe immunosuppression and abnormal kidney and liver function were excluded (P < 0.01).

CONCLUSION

The baseline serum albumin level is an independent predictor of mortality in HIV-1-infected women. The serum albumin level may be a useful additional marker of HIV-1 disease progression, particularly among asymptomatic women with little or no evidence of immunosuppression.

[The effect of treatment with enalapril versus losartan on levels of insulin resistance in patients with essential hypertension]

Insulin resistance and hyperinsulinaemia are presumed to participate in the pathogenesis of essential hypertension (EH). Insulin resistance is characterised by an impaired insulin-mediated glucose uptake. Participation of the renin-angiotensin system in the development of hyperinsulinaemia in EH patients has not been unanimously proven. The present study aimed to asses the influence of antihypertensive therapy with angiotensin converting enzyme inhibitor (ACEI, enalapril = 10 mg/day) (9 male patients) or angiotensin II AT-1 receptor blocker (A II RB = losartan 50 mg/day) (9 male patients) respectively on insulin sensitivity in patients with EH. 3-hours euglycaemic clamp test with constant infusion of insulin (50 mU/m2/min) was performed twice: before and after 8 weeks of therapy with ACEI or A II RB respectively. The control group (CG) consisted of 12 healthy males (clamp test was performed once). Serum insulin concentration (I) was estimated by radioimmunoassay. Glucose disposal rate (M-value = mg/kg/min) and tissue insulin sensitivity (M/I value = mg/kg/min per mU/l) were calculated in subjects of the CG and in patients with EH before and after antihypertensive therapy with ACEI or A II RB, respectively. In CG the M-value (7.38 +/- 0.13) and tissue insulin sensitivity (M/I = = 6.76 +/- 0.19) were significantly higher than in EH before treatment with ACEI (M-value = 5.44 +/- 0.16; M/I = = 4.57 +/- 0.18) or A II RB (M-value = 5.75 +/- 0.21; M/I = 4.77 +/- 0.31), respectively. ACEI therapy was followed by a significant increase of both M (6.82 +/- 0.25) and M/I (5.68 +/- 0.25) values. In contrast to ACEI, treatment with A II RB did not influence neither M (5.75 +/- 0.21) nor M/I (4.79 +/- 0.21) values respectively. In contrast to A II RB, ACEI shows a beneficial effect on insulin sensitivity in EH patients. This effect does not seem to be mediated by an influence on the AT-1 receptor.