Immunohistochemical detection of hepatocyte nuclear factor 1beta in ovarian and endometrial clear-cell adenocarcinomas and nonneoplastic endometrium

Recent studies have noted specific expression of hepatocyte nuclear factor (HNF) 1beta in ovarian clear-cell adenocarcinoma (CCA). In this study, we aimed to determine whether HNF-1beta can be a specific marker of CCA in both the ovary and the endometrium and to assess the pathological significance of HNF-1beta expression in CCAs. We examined HNF-1beta expression immunohistochemically in 186 ovarian carcinomas, including 40 CCAs; 33 endometrial carcinomas, including 5 CCAs; 22 endometria at different stages of the menstrual cycle (5 in the proliferative, 12 in the secretory, and 5 in the menstrual phases); and 7 gestational endometria. The incidence of HNF-1beta immunoreactivity differed significantly between CCAs and other histology in both the ovary (100% in the former versus 2% in the latter) and the endometrium (100% in the former versus 0% in the latter) (P < .0001 each). In nonneoplastic endometrium, 25% or more immunoreactive cells were confined to the mid-to-late secretory phase of the menstrual cycle and gestational endometrium. HNF-1beta would be an excellent marker for distinguishing CCAs from other lesions in both the ovary and the endometrium. HNF-1beta expression seems to be associated with physiopathological cytoplasmic glycogen accumulation in these organs.     

Effect of wrist position on distal radioulnar joint stability: A biomechanical study

We investigated distal radioulnar joint (DRUJ) stability in different wrist positions and examined the relative contribution of each ligamentous component of the triangular fibrocartilage complex (TFCC) to DRUJ stability. We used nine fresh‐frozen cadavers. The humerus and ulna were fixed at 90° elbow flexion. The radiocarpal unit was translated relative to the ulna in dorsopalmar directions with the wrist in five positions. Displacement of the unit was measured by an electromagnetic tracking device. Magnitudes of displacement were compared between different wrist positions in various sectioning stages: ulnocarpal ligament (UCL) sectioning, radioulnar ligaments (RUL) sectioning, and extensor carpi ulnaris (ECU) floor sectioning. Wrist position and sectioning stage significantly influenced the displacement. In intact wrists, the displacement in wrist extension was significantly lower than that in neutral. However, after UCL sectioning, there were no longer any significant differences. After RUL sectioning, the displacement in radial deviation was significantly lower than that in neutral. Following ECU floor sectioning, there were no longer any significant differences. Thus, in intact wrists, DRUJ stability in wrist extension is likely due to tightening of the UCL. After complete RUL sectioning, DRUJ is stabilized in radial deviation due to tightening of the ECU floor. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1247–1251, 2014.     

Reduced Frontal Glutamate + Glutamine and N-Acetylaspartate Levels in Patients With Chronic Schizophrenia but not in Those at Clinical High Risk for Psychosis or With First-Episode Schizophrenia

Changes in brain pathology as schizophrenia progresses have been repeatedly suggested by previous studies. Meta-analyses of previous proton magnetic resonance spectroscopy (¹H MRS) studies at each clinical stage of schizophrenia indicate that the abnormalities of N-acetylaspartate (NAA) and glutamatergic metabolites change progressively. However, to our knowledge, no single study has addressed the possible differences in ¹H MRS abnormalities in subjects at 3 different stages of disease, including those at ultrahigh risk for psychosis (UHR), with first-episode schizophrenia (FES), and with chronic schizophrenia (ChSz). In the current study, 24 patients with UHR, 19 FES, 25 ChSz, and their demographically matched 3 independent control groups (n = 26/19/28 for the UHR, FES, and ChSz control groups, respectively) underwent ¹H MRS in a 3-Tesla scanner to examine metabolites in medial prefrontal cortex. The analysis revealed significant decreases in the medial prefrontal NAA and glutamate + glutamine (Glx) levels, specifically in the ChSz group as indexed by a significant interaction between stage (UHR/FES/ChSz) and clinical status (patients/controls) (P = .008). Furthermore, the specificity of NAA and Glx reductions compared with the other metabolites in the patients with ChSz was also supported by a significant interaction between the clinical status and types of metabolites that only occurred at the ChSz stage (P = .001 for NAA, P = .004 for Glx). The present study demonstrates significant differences in ¹H MRS abnormalities at different stages of schizophrenia, which potentially correspond to changes in glutamatergic neurotransmission, plasticity, and/or excitotoxicity and regional neuronal integrity with relevance for the progression of schizophrenia.Key words: anterior cingulate cortex, at-risk mental state, biomarkers, frontal lobe, magnetic resonance imaging, neurochemical abnormality     

Hepatectomy-Related Hypophosphatemia: A Novel Phosphaturic Factor in the Liver-Kidney Axis

Marked hypophosphatemia is common after major hepatic resection, but the pathophysiologic mechanism remains unknown. We used a partial hepatectomy (PH) rat model to investigate the molecular basis of hypophosphatemia. PH rats exhibited hypophosphatemia and hyperphosphaturia. In renal and intestinal brush-border membrane vesicles isolated from PH rats, Na⁺-dependent phosphate (Pi) uptake decreased by 50%–60%. PH rats also exhibited significantly decreased levels of renal and intestinal Na⁺-dependent Pi transporter proteins (NaPi-IIa [NaPi-4], NaPi-IIb, and NaPi-IIc). Parathyroid hormone was elevated at 6 hours after PH. Hyperphosphaturia persisted, however, even after thyroparathyroidectomy in PH rats. Moreover, DNA microarray data revealed elevated levels of nicotinamide phosphoribosyltransferase (Nampt) mRNA in the kidney after PH, and Nampt protein levels and total NAD concentration increased significantly in the proximal tubules. PH rats also exhibited markedly increased levels of the Nampt substrate, urinary nicotinamide (NAM), and NAM catabolites. In vitro analyses using opossum kidney cells revealed that NAM alone did not affect endogenous NaPi-4 levels. However, in cells overexpressing Nampt, the addition of NAM led to a marked decrease in cell surface expression of NaPi-4 that was blocked by treatment with FK866, a specific Nampt inhibitor. Furthermore, FK866-treated mice showed elevated renal Pi reabsorption and hypophosphaturia. These findings indicate that hepatectomy-induced hypophosphatemia is due to abnormal NAM metabolism, including Nampt activation in renal proximal tubular cells.Inorganic phosphate (Pi) absorption in the renal proximal tubules and small intestine is important for Pi homeostasis.¹ The Na⁺-dependent Pi (Na/Pi) transport system includes type IIa and type IIc Na/Pi transporters, which are localized in the apical membrane of the proximal tubular cells, and type IIb Na/Pi transporters, which are localized in the apical membrane of the intestinal epithelial cells.^1,2 Pi (re)absorption is regulated by the dietary Pi content, parathyroid hormone (PTH), and the active metabolite of vitamin D, 1α, 25-dihydroxyvitamin D3 [1,25(OH)₂D₃].³ Other phosphaturic hormones, termed phosphatonins, also control renal Pi handling.⁴ The discovery that fibroblast growth factor (FGF) 23, the first identified phosphatonin,⁵ originated from osteocytes established the concept of the bone-kidney axis.^6,7The incidence of liver transplantation has steadily increased and the incidence of partial hepatectomy (PH) has also consequently increased.⁸ Hypophosphatemia frequently occurs after liver resection.^9–11 Acute hypophosphatemia causes septicemia and is associated with a poor prognosis.^11,12 Acute hypophosphatemia is of considerable clinical relevance because many hepatectomized patients develop marked hypophosphatemia and, thus, large doses of Pi replacement are required to maintain metabolic homeostasis.¹³ Urinary Pi excretion is markedly increased in many patients. After hepatectomy, hypophosphatemia is associated with hyperphosphaturia.¹³For many years, the increased metabolic demand of the regenerating liver was considered the underlying pathologic mechanism of hypophosphatemia. The magnitude of Pi uptake by the recovering liver, however, cannot explain the severity of the resulting hypophosphatemia.¹¹ Hepatectomy-induced hypophosphatemia is associated with an increased renal fractional excretion index for Pi unrelated to intact FGF23, FGF7, or secreted frizzled-related protein 4 as a phosphaturic factor,¹⁴ indicating that other factors have a role in the pathogenesis of hypophosphatemia.Nicotinamide (NAM) inhibits intestinal and renal Na/Pi transport activity in normal rats.^15–17 Administration of NAM to rats produces a specific dose-dependent inhibition of Na/Pi transport across the renal brush-border membrane (BBM) and an increase in urinary Pi excretion.^16,17 NAM suppresses hyperphosphatemia in hemodialysis patients.¹⁸ Nicotinamide phosphoribosyltransferase (Nampt) catalyzes the first rate-limiting step in converting NAM to NAD,^19,20 which is essential for cellular metabolism, energy production, and DNA repair.^20–22 Nampt exists in two known forms: intracellular Nampt (iNampt) and secreted extracellular Nampt (eNampt).²³ eNampt also generates an intermediate product, nicotinamide mononucleotide (NMN).²³Our findings indicate that the acceleration of NAM metabolism through Nampt function in the kidney is involved in the hepatectomy-induced hypophosphatemia in rodent models. This study also suggests that NAM metabolism through the liver-kidney axis is important in Pi homeostasis.     

Nuclear Notch3 Expression is Associated with Tumor Recurrence in Patients with Stage II and III Colorectal Cancer

Background

The importance of Notch signaling in colorectal cancer (CRC) tumorigenesis has been recently recognized. However, the significance of Notch3 expression and its association with Notch1 expression in CRC is unclear. In the present study, we investigated Notch1 and Notch3 expression in Stage II and III CRC to assess their association with clinicopathological characteristics.

Methods

The protein expression of Notch1 and Notch3 was examined using immunohistochemistry in 305 CRC specimens. Nuclear expression of Notch1 and Notch3 and their associations with clinicopathological characteristics and distant relapse-free survival (dRFS) were evaluated.

Results

Nuclear Notch1 was overexpressed in 37 % of specimen, and nuclear Notch3 in 38 %. Nuclear Notch3 expression correlated with tumor differentiation status (P = 0.0099). Nuclear expression of Notch1 and Notch3 was associated with tumor recurrence (P = 0.0311 and P = 0.0053, respectively). In multivariate analysis, nuclear Notch3 expression [hazard ratio (HR) = 1.71; 95 % confidence interval (CI), 1.06–2.78; P = 0.0271), lymph node metastasis, and venous involvement were independently correlated with dRFS. In subgroup analysis, nuclear Notch3 expression was strongly associated with dRFS in Stage II CRC (HR = 3.47; 95 % CI 1.44–9.22; P = 0.0055). Both nuclear Notch1 and Notch3 were positive in 67 specimens (22 %) and both were negative in 144 specimens (47 %). Coexpression of nuclear Notch1 and Notch3 had an additive effect toward poorer dRFS compared with a negative subtype (HR = 2.48; 95 % CI, 1.41–4.40; P = 0.0019).

Conclusions

Nuclear Notch3 expression might be a novel predictive marker for recurrence in Stage II and III CRC.