Gene expression profiling in aggressive digital papillary adenocarcinoma sheds light on the architecture of a rare sweat gland carcinoma.

BACKGROUND: Sweat gland carcinomas are rare cutaneous adnexal malignancies. Aggressive digital papillary adenocarcinoma (ADPA) represents a very rare subentity, thought to arise almost exclusively from the sweat glands of the fingers and toes. The aetiology of sweat gland carcinomas and ADPA is largely unknown. ADPAs are most likely driven by somatic mutations. However, somatic mutation patterns are largely unexplored, creating barriers to the development of effective therapeutic approaches to the treatment of ADPA. OBJECTIVES: To investigate the transcriptome profile of ADPA using a sample of eight formalin-fixed, paraffin-embedded tissue samples of ADPA and healthy control tissue. METHODS: Transcriptome profiling was performed using the Affymetrix PrimeView Human Gene Expression Microarray and findings were validated via reverse transcription of RNA and real-time quantitative polymerase chain reaction. RESULTS: Transcriptome analyses showed increased tumour expression of 2266 genes, with significant involvement of cell cycle, ribosomal and crucial cancer pathways. Our results point to tumour overexpression of FGFR2 (P = 0·001). CONCLUSIONS: The results indicate the involvement of crucial oncogenic driver pathways, highlighting cell cycle and ribosomal pathways in the aetiology of ADPA. Suggested tumour overexpression of FGFR2 raises the hope that targeting the fibroblast growth factor (FGF)/FGF receptor axis might be a promising treatment for ADPA and probably for the overall group of sweat gland carcinomas.

Identification of new TRIP12 variants and detailed clinical evaluation of individuals with non-syndromic intellectual disability with or without autism.

The ubiquitin pathway is an enzymatic cascade including activating E1, conjugating E2, and ligating E3 enzymes, which governs protein degradation and sorting. It is crucial for many physiological processes. Compromised function of members of the ubiquitin pathway leads to a wide range of human diseases, such as cancer, neurodegenerative diseases, and neurodevelopmental disorders. Mutations in the thyroid hormone receptor interactor 12 (TRIP12) gene (OMIM 604506), which encodes an E3 ligase in the ubiquitin pathway, have been associated with autism spectrum disorder (ASD). In addition to autistic features, TRIP12 mutation carriers showed intellectual disability (ID). More recently, TRIP12 was postulated as a novel candidate gene for intellectual disability in a meta-analysis of published ID cohorts. However, detailed clinical information characterizing the phenotype of these individuals was not provided. In this study, we present seven novel individuals with private TRIP12 mutations including two splice site mutations, one nonsense mutation, three missense mutations, and one translocation case with a breakpoint in intron 1 of the TRIP12 gene and clinically review four previously published cases. The TRIP12 mutation-positive individuals presented with mild to moderate ID (10/11) or learning disability [intelligence quotient (IQ) 76 in one individual], ASD (8/11) and some of them with unspecific craniofacial dysmorphism and other anomalies. In this study, we provide detailed clinical information of 11 TRIP12 mutation-positive individuals and thereby expand the clinical spectrum of the TRIP12 gene in non-syndromic intellectual disability with or without ASD.

Association screen for atopic dermatitis candidate gene regions using microsatellite markers in pooled DNA samples.

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting up to 16% of children in developed countries. A complex genetic background for AD has been suggested, with genetic as well as environmental factors influencing disease susceptibility. Among other factors, dysregulation in both the innate and the adaptive immune system has been proposed to play a role in AD pathophysiology. We present here an extended association screen for AD using microsatellite markers in 154 genes related to innate and adaptive immunity in pooled DNA samples from 150 German children with AD and 100 controls. After Bonferroni correction, no marker revealed a significant association with AD. Yet, markers representing the nuclear factor kappa B (NFKB)1 and chemokine receptor (CCR)4 genes showed differences in allelic distributions between cases and controls for both pooled DNA analysis and individual genotyping and were thus further investigated. Evaluation of additional single nucleotide polymorphisms (SNP) in the NFKB1 and CCR4 genes revealed no association of individual SNPs with AD. In contrast, haplotype analyses showed a significantly different haplotype distribution between patients and controls for CCR4 (P < 0.001). Furthermore, when SNP-SNP interaction effects were analysed for these two genes, we found significant evidence for epistatic interactions between SNPs within each of the two genes but no evidence for a gene-gene interaction, suggesting that variation in or near both the CCR4 and the NFKB1 genes might individually contribute to AD pathogenesis.

The cystic fibrosis transmembrane regulator (CFTR) in the kidney.

The cystic fibrosis transmembrane regulator (CFTR) is a Cl - channel. Mutations of this transporter lead to a defect of chloride secretion by epithelial cells causing the Cystic Fibrosis disease (CF). In spite of the high expression of CFTR in the kidney, patients with CF do not show major renal dysfunction, but it is known that both the urinary excretion of drugs and the renal capacity to concentrate and dilute urine is deficient. CFTR mRNA is expressed in all nephron segments and its protein is involved with chloride secretion in the distal tubule, and the principal cells of the cortical (CCD) and medullary (IMCD) collecting ducts. Several studies have demonstrated that CFTR does not only transport Cl - but also secretes ATP and, thus, controls other conductances such as Na+ (ENaC) and K+ (ROMK2) channels, especially in CCD. In the polycystic kidney the secretion of chloride through CFTR contributes to the cyst enlargement. This review is focused on the role of CFTR in the kidney and the implications of extracellular volume regulators, such as hormones, on its function and expression.

Apical plasma membrane mispolarization of NaK-ATPase in polycystic kidney disease epithelia is associated with aberrant expression of the beta2 isoform.

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disease of the kidney, characterized by cystic enlargement of renal tubules, aberrant epithelial proliferation, and ion and fluid secretion into the lumen. Previous studies have shown abnormalities in polarization of membrane proteins, including mislocalization of the NaK-ATPase to the apical plasma membranes of cystic epithelia. Apically located NaK-ATPase has previously been shown to be fully functional in vivo and in membrane-grown ADPKD epithelial cells in vitro, where basal-to-apical (22)Na transport was inhibited by application of ouabain to the apical membrane compartment. Studies were conducted with polymerase chain reaction-generated specific riboprobes and polyclonal peptide antibodies against human sequences of alpha1, alpha3, beta1, and beta2 subunits of NaK-ATPase. High levels of expression of alpha1 and beta1 messenger RNA were detected in ADPKD and age-matched normal adult kidneys in vivo, whereas beta2 messenger RNA was detected only in ADPKD kidneys. Western blot analysis and immunocytochemical studies showed that, in normal adult kidneys, peptide subunit-specific antibodies against alpha1 and beta1 localized to the basolateral membranes of normal renal tubules, predominantly thick ascending limbs of Henle's loop. In ADPKD kidneys, alpha1 and beta2 subunits were localized to the apical epithelial cell membranes, whereas beta1 was distributed throughout the cytoplasm and predominantly in the endoplasmic reticulum, but was not seen associated with cystic epithelial cell membranes or in cell membrane fractions. Polarizing, renal-derived epithelial Madin Darby canine kidney cells, stably expressing normal or N-terminally truncated chicken beta1 subunits, showed selective accumulation in the basolateral Madin Darby canine kidney cell surface, whereas c-myc epitope-tagged chicken beta2 or human beta2 subunits accumulated selectively in the apical cell surface. Similarly, human ADPKD epithelial cell lines, which endogenously expressed alpha1 and beta2 NaK-ATPase subunits, showed colocalization at the apical cell surface and coassociation by immunoprecipitation analysis. These results are consistent with a model in which the additional transcription and translation of the beta2 subunit of NaK-ATPase may result in the apical mislocalization of NaK-ATPase in ADPKD cystic epithelia.

Inhibitory effect of high [Mg2+] on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct.

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 +/- 27.2 microm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 +/- 57.2 microm/s (P<0. 05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 +/- 12.6 microm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 +/- 20.3 microm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3', 5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues.

Inhibitory effect of high [Mg2+]on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+&] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 + OR - 27.2 µm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 + OR - 57.2 µm/s (P<0.05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 + OR - 12.6 µm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 + or - 20.3 µm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3',5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues

Risk factors for recurrent bleeding and mortality in human immunodeficiency virus infected patients with acute lower GI hemorrhage.

BACKGROUND: Little is known about lower gastrointestinal (GI) hemorrhage in the human immunodeficiency virus (HIV) infected population. Our aim was to determine the underlying causes, the clinical outcome, and the risk factors for recurrent bleeding and mortality in HIV-infected patients with acute LGIH. METHODS: We reviewed the medical records of consecutive HIV-infected patients with acute lower GI hemorrhage who were evaluated with endoscopy from January 1992 through January 1997 at Bellevue Hospital Center. RESULTS: During the 5-year study period, 312 patients with acute lower GI hemorrhage underwent colonoscopy (n = 233) or flexible sigmoidoscopy (n = 79). Cytomegalovirus colitis (25.3%), lymphoma (12.2%), and idiopathic colitis (12.2%) were the most common causes identified. Within 30 days of presentation, recurrent bleeding occurred in 17.6% of patients. Independent predictors of recurrent bleeding included the presence of at least one comorbid illness, a hemoglobin level of less than 8 gm/dL, a platelet count of less than 100,000/mm3, and major stigmata of hemorrhage. The 30-day mortality from lower GI hemorrhage was 14.4%, and the presence of comorbid disease, recurrence of bleeding, and surgical intervention were found to be the only independent predictors of mortality in this patient population. CONCLUSIONS: Acute lower GI hemorrhage in HIV-infected patients is most commonly caused by cytomegalovirus colitis and is associated with a high short-term morbidity and mortality.

Effect of several electrolyte preservation solutions on the water permeability of isolated cortical collecting ducts perfused in vitro.

The extent of nephron injury after long-term preservation is unknown. An experimental protocol was designed to study the effects of 1 and 24 h of cold storage in preservation solution on renal slices of rabbit cortical collecting duct (CCD) isolated and perfused in vitro and evaluated by water hydraulic conductivity. The preservation solutions were Ringer-bicarbonate, Collins, Euro-Collins, and University of Wisconsin (UW). Under these experimental preservation conditions, the following results were observed: after 1 h of preservation, the CCDs obtained from slices incubated in Ringer-bicarbonate, Collins, and Euro-Collins solutions at 4 degrees C presented a high basal hydraulic conductivity compared to the control group and responded well to arginine-vasopressin (AVP) water permeability stimulation. The CCDs derived from renal slices stored for 24 h in Ringer-bicarbonate solution at 4 degrees C showed no function, while those preserved in Collins and Euro-Collins solutions showed a lack of responsiveness to AVP water permeability stimulation. The CCDs preserved in UW solution showed better values than those preserved in the other solutions, although there was a decrease in hydraulic conductivity after 24 h of preservation. These data show that long-term cold preservation with flushed solutions impairs the cortical collecting duct response to AVP.

Effect of propranolol and nifedipine on in vitro fluid absorption by the isolated perfused proximal convoluted tubule of the rabbit.

The inhibition of fluid absorption (Jv) by the antiarrhythmic and antihypertensive drugs propranolol and nifedipine, which increase cytosolic Ca2+ concentration, was studied using the isolated rabbit proximal convoluted tubule perfused in vitro. Proximal convoluted tubules were perfused and bathed with a modified Krebs-Henseleit solution containing bovine serum albumin. Jv was measured after a 30-min control period, after 40 min with either 0.1 mM propranolol or 1.0 mM nifedipine on the peritubular side and after a 40-min recovery period. Both drugs inhibited Jv (58% propranolol, and 21% nifedipine). The 40-min recovery period was sufficient to reverse the effect of nifedipine, but propranolol-treated tubules (N = 6) only reached 78% of the control Jv value. These results demonstrate that antiarrhythmic and antihypertensive drugs are powerful inhibitors of net fluid absorption by exerting a direct effect on proximal or distal tubule cells, thus acting like "local diuretics".

Effect of propranolol and nifedipine on in vitro fluid absorption by the isolated perfused proximal convoluted tubule of the rabbit

The inhibition of fluid absorption (Jv) by the antiarrhythmic and antihypertensive drugs propranolol and nifedipine, which increase cytosolic Ca*+ concentration, was studied using the isolated rabbid proximal convoluted tubule perfused in vitro. Proximal convuluted tubules were perfused and bathed with a modified Krebs-Henseleit solution containing bovine serum albumin. Jv was measured after a 30-min control period, after 40 min with eithe 0.1 mM propranolol or 1.0 mM mifedipine on the peritubular side and after a 40-min recovery period. Both drugs inhibited Jv (58% propranolol, and 21% nifedipine) The 40-min recovery period was sufficient to reserve the effect of nifedipine, but propranolol-treated tubules (N=6) only reached 78% of the control Jv value. These results demonstrate that antiarrhythmic and anthypertensive drugs are powerful inhbitors of net fluid absorption by exerting a direct effect on proximal or distal tubule cells, thus acting like "local diuretics"

Direct cholangiography.

The role of direct cholangiographic methods has evolved significantly over the last two decades as other high-resolution imaging modalities have become available. Most of the time, careful clinical evaluation of a patient combined with ultrasonography or CT will enable a physician to arrive at a correct diagnosis with a high level of precision. In this article we have attempted to indicate situations in which direct cholangiographic methods are necessary to diagnose and treat certain hepatobiliary problems. Considerable controversy exists concerning the application of these methods for treatment of biliary problems. However, in circumstances in which the issues are openly discussed, application of these techniques can be agreed on. Direct cholangiography, like coronary angiography, is a technology that provides considerable valuable information that at present cannot be obtained by other techniques, and, in well-defined circumstances, is necessary for precise diagnosis and therapy.

The effect of Collins' solution on the function and structure of isolated proximal convoluted tubules from rabbit kidneys.

Proximal convoluted tubules (PCTs) from rabbit cortical slices were perfused after preservation in Collins' solution with the in vitro microperfusion technique. Under these conditions, after maneuvers of in vitro preservation, the following findings were observed: Tubules were best preserved, functionally and morphologically, when bathed with Collins' solution peritubularly. Tubular preservation was inadequate when the Collins' solution contacted only the luminal or luminal and peritubular sides. These observations indicate a difference in the reactions of various cellular sides to the preservation process, suggesting that during preservation of the whole kidney, there are differences in the preservation of the various tissues of the organ.

Hemorrhoids or rectal varices: defining the cause of massive rectal hemorrhage in patients with portal hypertension.

Identifying the source of lower gastrointestinal hemorrhage in patients with chronic liver disease and portal hypertension can be challenging. We present 2 cases of hemorrhage from rectal varices and a discussion on the differences between simple hemorrhoids and rectal varices. Evaluation of rectal bleeding in patients with portal hypertension is discussed and possible therapeutic options are described.