Growth rates in pediatric dialysis patients and renal transplant recipients

We compared growth rates by modality over a 6- to 14-month period in 1,302 US pediatric end-stage renal disese (ESRD) patients treated during 1990. Modality comparisons were adjusted for age, sex, race, ethnicity, and ESRD duration using linear regression models by age group (0.5 to 4 years, 5 to 9 years, 10 to 14 years, and 15 to 18 years). Growth rates were higher in young children receiving a transplant compared with those receiving dialysis (ages 0.5 to 4 years, delta = 3.1 cm/yr v continuous cycling peritoneal dialysis [CCPD], P < 0.01; ages 5 to 9 years, delta = 2.0 to 2.6 cm/yr v CCPD, chronic ambulatory peritoneal dialysis (CAPD), and hemodialysis, P < 0.01). In contrast, growth rates in older children were not statistically different when comparing transplantation with each dialysis modality. For most age groups of transplant recipients, we observed faster growth with alternate-day versus daily steroids that was not fully explained by differences in allograft function. Younger patients (<15 years) grew at comparable rates with each dialysis modality, while older CAPD patients grew faster compared with hemodialysis or CCPD patients (P < 0.02). There was no substantial pubertal growth spurt in transplant or dialysis patients. This national US study of pediatric growth rates with dialysis and transplantation shows differences in growth by modality that vary by age group.

Type-1 and type-2 cytokines in human late-gestation decidual tissue

Evidence suggests that successful pregnancy in rodents requires the preferential stimulation of type-2 cytokine production by gestation-associated tissues. The ability of human gestation-associated tissue to synthesize type-2 and type-1 cytokines has not been examined in detail and was the subject of this study. Decidual tissue collected at term, either before the onset of labor (elective caesarean section) or at the completion of labor, expressed mRNA for interleukin (IL)-10 and interferon gamma (IFN-gamma) and produced IL-10 and IFNgamma protein in vitro. IL-4 mRNA or protein was not detected. IFNgamma production in vitro was significantly decreased by decidual cells prepared from decidua collected after labor as compared with those collected before the commencement of labor, a change that may be associated with prostaglandin E2 (PGE2) production in conjunction with labor. IFNgamma, IL-4, and IL-10 were detectable in human amniotic fluid collected at term. There was no significant difference in the levels of IL-4, IFNgamma, or IL-10 in samples collected before labor onset or during labor. Thus, late-gestation human decidual tissue and amniotic fluid do not preferentially express a type-2 cytokine profile of cytokines. This is not consistent with observations of a predominant type-2 cytokine profile in gestation-associated tissues in murine pregnancy.

Adenosine A3 receptors promote degranulation of rat mast cells both in vitro and in vivo

OBJECTIVE

To investigate the effects of adenosine receptor agonists and antagonists on 5-HT release from rat isolated pleural mast cells and on plasma protein extravasation in the skin of conscious rats. In vitro

METHODS

Rat isolated pleural mast cells were loaded with [14C] 5-HT, sensitised with mouse monoclonal anti-DNP and then challenged with human serum albumin-DNP. DNP-stimulated 5-HT release from mast cells was determined. In vivo

METHODS

Rats, loaded intravenously with [125I] human serum albumin, were injected intradermally with adenosine agonists at sites on the back. 30 min later plasma protein extravasation at each injection site was determined.

RESULTS

In isolated mast cells, each adenosine agonist enhanced DNP-induced 5-HT release, N6-(3-iodobenzyl)-5-(N-methyl-carboxamidoadenosine), (IB-MECA), being the most potent agonist. The adenosine A1/A2 antagonist, 8-phenyltheophylline (8-PT), had no effect on the response to IB-MECA. In contrast, 3-(4-amino-iodobenzyl)-8-[4-[[[carboxy]methyl]oxy]phenyl]-1-propylxanthi ne, (I-ABOPX), inhibited (pA2 6.2) the IB-MECA responses. In the skin of conscious rats, intradermal IB-MECA produced a marked plasma protein extravasation (PPE) which was mimicked by N6-2-(4-aminophenyl)-ethyladenosine (APNEA). The PPE produced by IB-MECA was not affected by either 8-PT or CGS15943A, but was virtually abolished by cyproheptadine and in rats pre-treated with Compound 48/80.

CONCLUSIONS

These results indicate that stimulation of adenosine A3 receptors both enhances degranulation in vitro and directly produces degranulation of rat mast cells in vivo.

An scl gene product lacking the transactivation domain induces bony abnormalities and cooperates with LMO1 to generate T-cell malignancies in transgenic mice

The product of the scl (also called tal-1 or TCL5) gene is a basic domain, helix-loop-helix (bHLH) transcription factor required for the development of hematopoietic cells. Additionally, scl gene disruption and dysregulation, by either chromosomal translocations or a site-specific interstitial deletion whereby 5' regulatory elements of the sil gene become juxtaposed to the body of the scl gene, is associated with T-cell acute lymphoblastic leukemia (ALL) and T-cell lymphoblastic lymphoma. Here we show that an inappropriately expressed scl protein, driven by sil regulatory elements, can cause aggressive T-cell malignancies in collaboration with a misexpressed LMO1 protein, thus recapitulating the situation seen in a subset of human T-cell ALL. Moreover, we show that inappropriately expressed scl can interfere with the development of other tissues derived from mesoderm. Lastly, we show that an scl construct lacking the scl transactivation domain collaborates with misexpressed LMO1, demonstrating that the scl transactivation domain is dispensable for oncogenesis, and supporting the hypothesis that the scl gene product exerts its oncogenic action through a dominant-negative mechanism.

Renal calcification in preterm infants: follow up at 4-5 years

AIM

To determine the consequences of renal calcification in preterm infants.

METHODS

A cohort of 11 preterm babies was studied at the age of 4 to 5 years. They had had renal calcification as neonates. Seventeen matched controls were also studied. Each child had a renal ultrasound scan, a calcium load test, and a desmopressin test for renal concentrating ability (RCA). The study group also had glomerular filtration rate (GFR) estimated, using the height:creatinine ratio, and tubular phosphate reabsorption, without phosphate load, per glomerular filtration rate (Tp/GFR) calculated,

RESULTS

In the study group the median GFR was 61 ml/min/1.73m2 (range 46-79 ml/min/1.73m2) and the median calculated Tp/GFR SD score was -0.94 (range -2.8-0.68). Five children out of the study group had ultrasonic evidence of renal calcification. There was no significant difference between the two groups in renal size, calciuria, before or after calcium load, or RCA. Eight children (three patients, five controls) had an abnormal calcium load test. The RCA of the children in the study and control groups combined was below that of published values, with a median calculated SD score -0.71 (95% CI -1.21 to -0.23).

CONCLUSIONS

There was evidence of renal dysfunction in children who had been born preterm. Renal calcification detected in the neonatal period does not seem to be a major predisposing factor for the abnormalities of renal function subsequently observed in these infants.

Epidemiology of interstitial cystitis

OBJECTIVES

To discuss what is currently known about the population prevalence of interstitial cystitis (IC) and demographic characteristics of IC patients.

METHODS

Changes over time in the criteria for diagnosis of IC are described. The 3 published studies of the population prevalence of IC are reviewed. Epidemiologic issues important in the design of studies of IC are cited.

RESULTS

IC is a disease of chronic voiding symptoms. There is very little reliable information published on the etiology, risk factors, or number of persons affected. The criteria used for diagnosis of IC by different investigators have been variable. In 1988, research criteria for a case definition of IC were published, to be applied for IC patients enrolled in National Institutes of Health-funded studies. Three published studies of the population prevalence of IC are available. Each study used different criteria for defining a case of IC, and none used the NIH research criteria to define a case. Prevalence estimates for IC vary significantly, from 10 cases/100,000 reported in Finland in 1975, (based on hospital record review), to 30/100,000 in the United States in 1987, (based on a mailed survey of board certified urologists), to 510 cases/100,000 in the United States in 1989, (based on participant self-report in the 1989 National Health Interview Survey). It is unclear the extent to which these estimates represent true differences in prevalence, rather than reflect the different methods used to define an IC case. Several investigators have reported demographic characteristics of the IC patients followed in their clinics. All studies of adults show a marked female predominance, with reported onset of symptoms generally in the middle years of life. Patients may experience a delay of years from the onset of symptoms to the time of definitive diagnosis. The natural history of symptoms of IC has been reported to be that of a subacute onset with a rapid peak in severity, and then a relatively constant plateau of chronic symptoms thereafter. However, many patients do experience remissions and flares in their disease symptoms.

CONCLUSIONS

Few therapies for IC have been evaluated using rigorous epidemiologic methods. Many questions remain to be answered. New studies of IC should include epidemiologic consultation at the stage of study design.

Isolation of chromosome-specific paints from high-resolution flow karyotypes of the sheep (Ovis aries)

High-resolution bivariate flow karyotypes were obtained using fibroblast cell lines from a sheep with a normal karyotype (2n = 54), from sheep carrying Robertsonian translocation chromosomes and from sheep-hamster somatic cell hybrids. By taking advantage of the presence of chromosome polymorphisms, translocation chromosomes and sheep-hamster somatic cell hybrids, all sheep chromosomes were isolated by flow sorting. Chromosome-specific paints were generated from each sorted peak using degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR). The sheep chromosome present in each peak was identified by chromosome-specific microsatellite analysis of the DOP-PCR products and fluorescence in situ hybridization (FISH) onto DAPI-banded sheep metaphase chromosomes. The chromosome-specific DNA obtained in this study can be used for the production of genomic libraries and as a resource for mapping randomly cloned DNA sequences that will greatly aid the construction of genetic and physical maps in the sheep. The chromosome-specific paints will facilitate chromosome identification and contribute to the study of karyotype evolution in the sheep and related species.

Biosynthesis of renin in mouse kidney tumor As4.1 cells

As4.1, a renin-expressing cell line isolated from a mouse renal tumor, was characterized for synthesis, processing, storage and secretion of renin polypeptides. Metabolic labeling, immunoprecipitation and SDS/PAGE analysis revealed that renin was secreted into the culture supernatant predominantly in the form of prorenin which migrated as products of 42-47 kDa. The predominant intracellular renin was processed into two chains, of 33-34 and 5 kDa. N-glycanase treatment removed N-linked oligosaccharides and yielded products of 41 kDa for prorenin and 31-32 kDa for the heavier chain of two-chain renin. The N-terminus of the constitutively secreted prorenin was determined by automated Edman degradation to be Leu22 while the N-terminus of the heavy chain was Ser72. Renin polypeptides constituted 3.1 +/- 1.4% (mean percentage of total precipitable radioactivity +/- SD) of de-novo-synthesized protein secreted into the medium and 0.2 +/- 0.17% retained intracellularly. Extrapolation of renin activity assays suggest that a single cell stores approximately 680 fg of active renin. A slow incremental release into the medium of processed renin heavy chain was detected by immunoprecipitation and SDS/PAGE. Renin activity assays confirmed the release of approximately 4 fg prorenin and 0.32 fg active renin cell(-1) h(-1). Indirect immunofluorescence demonstrated intracellular renin to be distributed in a punctate pattern. Renin was found to be colocalized with the lysosomal marker, beta-glucuronidase, by double-fluorescent labeling. These cells have enabled characterization of glycosylated mouse renin-1 and may prove a valuable tool for studying intracellular trafficing of renin and associated processing enzymes.

Immune responses during pregnancy and the development of allergic disease

It is now established that allergen exposure in the first few months of life is important in the development of specific allergic sensitisation (1, 2). Furthermore, the immune response of infants born to families with a strong history of allergic disease is relatively immature at birth in comparison to infants with no family history of allergies, with reduced production of Interferon-gamma (IFN-gamma) (3-5) and lower levels of T cell activation and memory (6). It therefore seems logical that the interaction of these two factors must be important in the ontogeny of allergic disease.

Control of major histocompatibility complex class II expression on human monocytes by interleukin-4: regulatory effect of lipopolysaccharide

Interleukin-4 (IL-4), like interferon-gamma (IFN-gamma), stimulates monocyte major histocompatibility complex (MHC) class II expression and thus, by increasing antigen presentation, has the potential to increase immune reactivity. In this study, activation of human monocytes by lipopolysaccharide (LPS) prevented concomitant IL-4 stimulation of MHC class II expression. However, this was not a general observation for activated monocytes because although the high levels of MHC class II antigen expressed by monocytes stimulated in vitro with IFN-gamma were not further regulated by IL-4, the stimulatory effects of IL-4 persisted on cells activated with granulocyte macrophage colony-stimulating factor and tumour necrosis factor-alpha for enhanced MHC class II expression. MHC class II expression by monocytes cultured for 7 days with macrophage colony-stimulating factor was regulated by IL-4 and LPS in a manner very similar to that detected for freshly isolated monocytes. The inhibitory effect of LPS was not due to LPS-induced production of IL-10 or regulatory prostanoids. Furthermore, IFN-gamma-increased MHC class II expression was suppressed by LPS, suggesting that the regulation was at the level of MHC class II expression per se. This study suggests that during Gram-negative bacterial infections, IL-4 and IFN-gamma may not be able to signal enhanced MHC class II expression and thus, enhanced immune reactivity.

Papanicolaou staining of air-dried smears: value in rapid diagnosis

Air-dried material normally submitted for Diff-Quik (modified Romanowsky stain) was rehydrated in normal saline, then fixed for a short period in formol alcohol, before staining by a modified Papanicolaou technique. Staining was performed by a rapid manual technique (< 2 min) if urgent or routinely on an automatic stainer. Comparisons were made between wet-fixed Papanicolaou-stained specimens and air-dried Papanicolaou-stained material. Air-dried material stained after rehydration showed superior nuclear definition compared with wet-fixed material; the removal of erythrocytes enhanced the staining of the remaining epithelial cells.

Role of proximal promoter elements in regulation of renin gene transcription

Mouse As4.1 cells, obtained after transgene-targeted oncogenesis to induce neoplasia in renal renin-expressing cells, express high levels of renin mRNA from the endogenous Ren-1(c) gene. We have used these cells to characterize the role of the Ren-1(c) proximal promoter (+6 to -117) in the regulation of renin gene transcription. It was found that 4.1 kilobases (kb) of Ren-1(c) 5'-flanking sequence, in combination with the proximal promoter, are required for strong activation (approximately 2 orders of magnitude over the basal level of the promoter alone) of the chloramphenicol acetyltransferase reporter in transfection assays. Within the 4.1-kb fragment, a 241-base pair region was identified that retains full activity in an orientation-independent manner in combination with the promoter. The resulting transcripts initiate at the normal renin start site. Electrophoretic mobility shift assays identified a sequence at approximately position -60 in the promoter region that binds nuclear proteins specific for renin-expressing As4.1 cells. Mutations in this sequence, which disrupt binding of nuclear protein(s), completely abolish activation of transcription by the 4. 1-kb fragment. Activation of transcription by the 241-base pair enhancer was still observed, although it was diminished in magnitude (60-fold over the mutated promoter alone). We present a model derived from the current data that suggests that regulation of renin expression is achieved through cooperation of transcription factors binding at the proximal promoter element and a distal enhancer element to abrogate or override the effects of an intervening negative regulatory region.

Relationship of dose of hemodialysis and cause-specific mortality

A number of studies have found a relationship of lower all-cause mortality risk for ESRD patients treated with increasing dose of dialysis. The objective of this study was to determine the relationship of delivered dose of dialysis with cause-specific mortality. Data from the USRDS Case Mix Adequacy Study, which includes a national random sample of hemodialysis patients, were utilized. To minimize the contribution of unmeasured residual renal function, the sample used in this analysis (N = 2479) included only patients on dialysis for one year or more. Cox proportional hazards models, stratified for diabetes, were used to analyze the effect of delivered dose of dialysis (measured and reported by both Kt/V and URR) on major causes of death and withdrawal from dialysis, adjusting for other covariates including demographics, comorbid diseases present at start of study, functional status, laboratory values and other dialysis parameters. Patient follow-up for mortality was censored at the earliest of time of transplantation, 60 days after a switch to peritoneal dialysis or at the time of data abstraction. For each 0.1 higher Kt/V, the adjusted relative risk of death due to coronary artery disease was 9% lower (RR = 0.91, P < 0.05), due to other cardiac causes was 12% lower (RR = 0.88, P < 0.01), due to cerebrovascular disease (CVD) was 14% lower (RR = 0.86, P < 0.05), due to infection was 9% lower (RR = 0.91, P = 0.05), and due to other known causes was 6% lower (RR = 0.94, P < 0.05). There was no statistically significant relationship of Kt/V and risk of death among patients who died of malignancy (RR = 0.84, P = 0.10) or among patients whose death cause was missing (RR = 0.95, P = 0.41). The risk of withdrawal from dialysis prior to death due to any cause was 9% lower (RR = 0.91, P < 0.05) for each 0.1 higher Kt/V. The relationships of delivered dose of dialysis, as measured by URR, and cause-specific mortality were essentially similar in relative magnitude and statistical significance as the relationships observed using Kt/V as the measurement of dialysis dose, with the exception that the relationship was less significant for cerebrovascular disease and withdrawal from dialysis. The relationship of dialysis dose with risk of death due to each cause of death category except other cardiac causes and "other" causes appeared to be of greater magnitude and of greater statistical significance among diabetics than non-diabetics. These results indicate that low dose of dialysis is not associated with mortality due to just one isolated cause of death, but rather is due to a number of the major causes of death in this population. This study is consistent with hypotheses that low doses of dialysis may promote atherogenesis, infection, malnutrition and failure to thrive through a variety of pathophysiologic mechanisms. Further study is necessary to confirm these results and to test hypotheses that are developed.

Recruitment experience in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study

Several approaches for recruitment of African American adults with renal insufficiency due to hypertension (glomerular filtration rate between 25 and 70 ml/min/1.73 m2) were explored in the Pilot Study for the African American Study of Kidney Disease and Hypertension (AASK). Over a period of 42 weeks, prescreening information was obtained on 2880 individuals, of whom 498 (17%) were evaluated at a screening visit. Two hundred and twenty-five (8%) had an 125I-iothalamate assessment of glomerular filtration rate. Ninety-four of 97 participants who met all the study eligibility criteria were enrolled in the trial. The most common reasons for ineligibility during screening were absence of renal insufficiency or hypertension, presence of diabetes mellitus, and a body mass index above the acceptable level. Overall, an average of 31 prescreen contacts and 8 screening visits were conducted for every randomization (3.3% yield from prescreening to randomization). Screening in clinical practice was the most efficient method for recruitment (12.6% yield from prescreen contact to randomization compared to 1.1% from mass mailing campaigns, 1.3% from mass media campaigns, and 1.7% from referrals by patients with end-stage renal disease). Randomization yields increased with progressively higher age ranges (2.4%, 3.3%, and 6.0% prescreen to randomization yields for those aged < or = 50, 51-60, and 61-70, respectively). A slight majority (51%) of the prescreen contacts were women, but 75% of the randomized participants were men. Our results suggest that clinic-based screening is an effective approach for recruitment of African Americans with hypertension and renal insufficiency into clinical trials. They also suggest that enrollment of African American women in such studies is a special challenge.

A cohort analysis of pre-menopausal women with dysfunctional uterine bleeding

OBJECTIVE

To examine the clinical and cost outcomes of patients with dysfunctional uterine bleeding (DUB) who are treated with hysterectomy or not.

DESIGN

A retrospective analysis of DUB patients over 30 months of treatment after initial diagnosis.

SETTING

Patients with DUB from an HMO with over 200,000 enrollees.

PARTICIPANTS

Study patients, all women with an initial diagnosis of DUB, were divided into two cohorts. Cohort 1 was women who had a hysterectomy (not for cancer); Cohort 2 was women who did not have a hysterectomy.

MAIN OUTCOME MEASURES

Visit counts and costs, prescription counts and costs, hospital costs, and procedure counts.

RESULTS

Hysterectomy patients in our dataset tend to have more prescriptions, higher prescription costs, more visits overall, higher visit costs, higher hospitalization costs, and higher total costs per member per month (PMPM) than non-hysterectomy patients. After surgery, the hysterectomy patients' costs and utilization PMPM are higher than those for the non-hysterectomy patients.

CONCLUSIONS

There is wide variation in the treatment of patients with DUB. Clinical practice improvement studies are needed to determine the appropriate treatments based on patient characteristics to achieve better outcomes for lower costs.

The capacity to accumulate cyclic AMP in the preoptic-anterior hypothalamic area of the rat is affected by the exposition to low ambient temperature and the subsequent recovery

The accumulation of adenosine 3':5'-cyclic monophosphate (cAMP) was measured in the preopticanterior hypothalamic area, the cerebral cortex, and the hippocampus of rats exposed to different ambient temperatures: (1) 23 +/- 0.5 degrees C, for 53 h +/- 20 min (control); (2) -10 +/- 1 degrees C, for 53 h +/- 20 min (exposure to low ambient temperature); (3) -10 degrees C for 48 h and 23 degrees C for the following 5 h +/- 20 min (recovery). The capacity to accumulate cAMP was tested by subjecting animals to acute hypoxia, a stimulus which is known to induce a large increase in brain cAMP concentration. In the control condition, hypoxic stimulation increases cAMP concentration in all the brain regions studied. In contrast, during the exposure to low ambient temperature, whilst both the cerebral cortex and the hippocampus show the same levels of accumulation found in the control condition, cAMP accumulation is reduced in the preoptic-anterior hypothalamic area. However, during the first few hours of the recovery period, the preoptic-anterior hypothalamic area is able to reattain the capacity for cAMP accumulation observed in the control condition.

Human herpesvirus-6 infections

HHV-6 is ubiquitous in the community, appears to be acquired early in life, and has been proved to cause the clinical syndrome of exanthem subitum, and rarely to cause encephalitis. Like other herpesviruses, HHV-6 is capable of establishing latent infection and reactivating under a variety of stimuli. Improved diagnostic techniques have led to increased recognition of HHV-6 in the presence of many diseases, but much of the evidence for an aetiological role is inconclusive. There is accruing evidence for possible pathological roles in the immunocompromised host, but the evidence is less convincing for the range of associations otherwise listed for the normal host at the present time.

Replication in UV-irradiated Caenorhabditis elegans embryos

Replication continues in wild-type (but not rad mutant) Caenorhabditis elegans embryos even after exposure to massive fluences of UV radiation. It is of interest to elucidate the mechanism(s) for this "damage-resistant" DNA synthesis. In this study, DNA from unirradiated and UV-irradiated wild-type embryos was examined using the electron microscope. Large fluences of UV radiation (180 J m-2) had little effect on either replication bubble size or distances between bubbles in wild-type embryos, indicating that the damage-resistant DNA synthesis was not grossly aberrant. Conversely, UV irradiation significantly decreased center-to-center distances between bubbles in excision-repair-deficient rad-3 embryos. This suggests that the decreased DNA synthesis observed after UV irradiation in rad-3 embryos is due largely to blockage of elongation of DNA synthesis.

Undetectable interleukin (IL)-10 and persistent IL-8 expression early in hyaline membrane disease: a possible developmental basis for the predisposition to chronic lung inflammation in preterm newborns

We are interested in determining whether premature birth alters expression of counterregulatory cytokines which modulate lung inflammation. Production of proinflammatory cytokines tumor necrosis factor alpha. IL-1 beta, and IL-8 is regulated in part by the antiinflammatory cytokine IL-10. For preterm newborns with hyaline membrane disease, deficiencies in the ability of lung macrophages to express antiinflammatory cytokines may predispose to chronic lung inflammation. We compared the expression of pro- and antiinflammatory cytokines at the mRNA and protein level in the lungs of preterm and term newborns with acute respiratory failure from hyaline membrane disease or meconium aspiration syndrome. Four sequential bronchoalveolar lavage (BAL) samples were obtained during the first 96 h of life from all patients. All patients rapidly developed an influx of neutrophils and macrophages. Over time, cell populations in both groups became relatively enriched with macrophages. The expression of proinflammatory cytokine mRNA and/or protein was present in all samples from both patient groups. In contrast, IL-10 mRNA was undetectable in most of the cell samples from preterm infants and present in the majority of cell samples from term infants. IL-10 concentrations were undetectable in lavage fluid from preterm infants with higher levels in a few of the BAL samples from term infants. These studies demonstrate that 1) IL-10 mRNA and protein expression by lung inflammatory cells is related to gestational age and 2) during the first 96 h of life neutrophil cell counts and IL-8 expression decrease in BAL from term infants, but remain unchanged in BAL samples from preterm infants.

End-stage renal disease in the USA: data from the United States Renal Data System

Treated end-stage renal disease continues to increase at an alarming rate in the US. There has been an exponential growth in the incidence rate between 1982 and 1991 at the rate of 8.76% per year. Approximately 218,042 patients received treatment for ESRD in 1991, of which 49,909 were new patients. Although the increase in the incidence rate is seen for all the major disease categories responsible for ESRD, diabetes mellitus, probably type 2, and hypertension are responsible for the bulk of the increase. African Americans and Native Americans have shown the most dramatic increase; diabetes being the major reason for both races, but for African Americans, hypertension is the leading cause of ESRD. A bulk of the increase in the ESRD patient population has been in the older age (greater than 65 years of age) group. The mortality rate for the ESRD patient population, and, specifically, for the dialysis population remains relatively high, with 1-year survival probabilities of approximately 78%. Some of the contributing factors cited for the high death rate, especially in the dialysis patient population include inadequate dialysis dose, low flux of the dialysis membranes, shortened dialysis times, an increase in the age of the ESRD population, and bioincompatible dialysis membranes. The effect of the widely practiced dialyzer reuse on dialysis patient morbidity and mortality remains unclear.

Tryptase, the dominant secretory granular protein in human mast cells, is a potent mitogen for cultured dog tracheal smooth muscle cells

Hyperplasia of airway smooth muscle cells is present in the airways of asthmatic patients and may contribute to the development of the bronchial hyperresponsiveness that occurs in these patients. Because tryptase is an abundant component of mast cell granules and has demonstrated growth-stimulatory effects in other mesenchymal cells (J. Clin. Invest. 1991; 88:493-499), the goal of our study was to determine whether tryptase is a mitogen for airway smooth muscle cells. The mitogenic effects of tryptase were tested in passages 1 through 5 of dog tracheal smooth muscle cells, either by counting smooth muscle cells or by monitoring uptake of bromodeoxyuridine (BrdU) into cellular DNA during S-phase. With respect to its efficacy, at a near maximal concentration (4 nM), tryptase increased cell numbers 2.1 +/- 0.2- or 2.8 +/- 0.6-fold above controls after 2 or 4 days, respectively, and these increases were approximately the same as those induced by platelet-derived growth factor (50 ng/ml) or 10% calf serum. With respect to potency, tryptase caused concentration-dependent increases in BrdU uptake, as detected in an enzyme-linked immunosorbent assay or by counting BrdU-labeled nuclei, with an EC50 of 2 nM. Pretreatment of tryptase with diisopropylfluorophosphate, to reduce markedly its catalytic as a activity as a proteinase, attenuated its growth-stimulated effects by 58 +/- 16%. Tryptase-induced mitogenesis was not a nonspecific effect of all serine proteinases, because thrombin, another proteinase with mitogenicity for fibroblasts, stimulated neither increases in cell counts nor BrdU uptake in our cells. We conclude that tryptase is a potent mitogen for airway smooth muscle cells in culture.

Use of granulocyte colony stimulating factor to reduce the toxicity of super-VAC chemotherapy in advanced solid tumours in childhood

Children with advanced solid tumours at the Royal Alexandra Hospital for Children (RAHC) receive an intensive four drug chemotherapy combination, Super-VAC (cyclophosphamide, 500 mg/m2, adriamycin, 30 mg/m2, actinomycin-D, 0.5 mg/m2, all daily for 3 days, and vincristine, 1.5 mg/m2 weekly). The majority of patients respond well to three courses of such therapy, but with considerable morbidity, including fever, neutropenia, and mucositis. In an attempt to reduce the morbidity of Super-VAC, G-CSF was added. We documented various parameters in 12 patients who received 28 cycles with G-CSF and compared them to an historical control group of 37 cycles in the preceding 14 patients who received Super-VAC. The median duration of each cycle was 23 days with G-CSF and 28 days without G-CSF (P = 0.004). However, differences in requirements for inpatient care (median 16 v. 20 days), intravenous antibiotics (median 9 v. 10 days), amphotericin (median 5 v. 3 days), morphine (median 8.5 v. 7 days), or TPN (median 6.5 v. 8 days) did not reach statistical significance. As expected, a significant difference in neutrophil recovery was demonstrated between the two groups (median 11 v. 16 days, P < 0.0001) but not in platelet recovery (median 13 v. 13 days). The use of G-CSF with Super-VAC resulted in a shorter cycle length, so increasing the dose intensity. A reduction in morbidity could not be demonstrated. No toxic side effects from G-CSF were noted.

cAMP accumulation in the hypothalamus, cerebral cortex, pineal gland and brown fat across the wake-sleep cycle of the rat exposed to different ambient temperatures

The concentration of adenosine 3':5' cyclic monophosphate (cAMP) was determined in the anteroventro-medial hypothalamus, the cerebral cortex, the pineal gland and the interscapular brown adipose tissue, during the different stages of the wake-sleep cycle of rats kept, under a 12-12-h light-dark cycle, in different environmental conditions, i.e., control (47-52 h at ambient temperature (Ta) 23 +/- 0.5 degrees C), exposure (47-52 h at Ta 0 +/- 1 degree C) and recovery (1-4 h at Ta 23 degrees C after 48 h at Ta 0 degree C). The results show that cAMP concentration consistently changed: (1) during the wake-sleep cycle in the anteroventro-medial hypothalamus, decreasing from wakefulness to sleep; (2) during the dark-light transition in the pineal gland, increasing with the onset of the light phase; and (3) with the environmental condition in the interscapular brown adipose tissue increasing, with respect to the control condition, in exposure and recovery. No significant changes in cAMP concentration were observed in the cerebral cortex.

Monocytes cultured in cytokine-defined environments differ from freshly isolated monocytes in their responses to IL-4 and IL-10

To investigate the regulatory effects of the prototypic Th2 lymphocyte products and potential immunotherapeutic agents interleukin-4 (IL-4) and IL-10 on macrophages differentiated in vitro under different cytokine-defined environments, blood monocytes were incubated for 7 days in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor or IL-4. The effect of monocyte culture in the presence or absence of serum was also investigated. Functional responses by 7-day-cultured cells to IL-4, quantified as decreased CD14 expression and suppression of lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-alpha) and IL-1 beta production, and as a positive response, increased CD23 expression, were compared directly with the responses by monocytes from which they were derived. In response to IL-10, decreases in LPS-induced TNF-alpha and IL-1 beta production and reduction in the expression of major histocompatibility complex (MHC) class II antigens were examined. Seven-day cultured monocytes/macrophages showed (1) diminished TNF-alpha production in response to IL-10 but not IL-4 (2), diminished IL-1 beta production in response to both IL-4 and IL-10, and compared with fresh monocytes (3), diminished CD14 expression in response to IL-4, and (4) a lesser increase in CD23 expression in response to IL-4. This was the case regardless of the cytokine in the presence of which the cells had been cultured for 7 days. Monocytes cultured for 7 days in GM-CSF expressed increased levels of MHC class II and LPS-induced TNF-alpha and responded inefficiently to IL-10 for decreased MHC class II. The responses by monocytes cultured for 7 days with GM-CSF resemble the published properties of synovial fluid macrophages from patients with chronic inflammatory arthritis. The study highlights the complexity of monocyte/macrophage responses to the immunoregulatory cytokines IL-4 and IL-10 and concludes that responses to IL-4 and IL-10 by blood monocytes may not be representative of responses by their differentiated or activated counterparts.