Bone response to free form-fabricated hydroxyapatite and zirconia scaffolds: a histological study in the human maxilla

Objectives: Synthetic and biological materials are increasingly used to provide temporary or permanent scaffolds for bone regeneration. This study evaluated the effect of material chemistry and microporosity on bone ingrowth and osseointegration of zirconia (ZrO₂) and hydroxyapatite (HA) scaffolds in the human maxilla.
Material and methods: Twelve patients subjected to dental implant placement were enrolled in the study. Scaffolds of ZrO₂ and HA were placed in the maxilla of each subject, using a randomization protocol. After 3 months of healing, biopsies were harvested comprising the scaffolds and surrounding bone tissue. The biopsies were processed for histological evaluation and morphometric analysis (bone ingrowth and bone-to-scaffold contact).
Results: Healing was uneventful in all cases. All scaffolds demonstrated a measurable bone response using light microscopy and scanning electron microscopy. Microporous HA scaffolds revealed four times larger bone ingrowth and seven times larger bone contact as compared with ZrO₂ scaffolds.
Conclusion: The results show that chemistry and microporosity of HA promote bone ingrowth and bone contact of ceramic scaffolds in human maxilla.     

Biochemical/metabolic changes associated with hepatocellular carcinoma development in mice

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality after lung and stomach cancers. This work was undertaken to investigate some of the biochemical mediators/pathways associated with or implicated in the pathogenesis of HCC. Male albino mice were classified into two groups: normal control group and HCC group. Early stage HCC was induced by injection of diethylnitrosamine (DEN) i.p. 200 mg/kg as a single dose, and after 2 weeks, the mice were given i.p. injection of thioacetamide (TAA) 100 mg/kg twice per week for 4 weeks. Mice were left for further 2 weeks without any treatment, after which, mice were sacrificed; blood and liver samples were collected. Serum was used for determination of activities of glucose-6-phosphate dehydrogenase (G6PDH) and aldolase as well as levels of insulin-like growth factor-1 (IGF-1) and epithelial cadherin (E-cadherin). One portion of the liver was used for histopathological examination and immunohistochemical staining of the tumor suppressor p53 protein. Another portion of the liver was used for determination of citrate synthase activity. Induction of HCC in mice resulted in significant increase in G6PDH and aldolase activities, and E-cadherin level, but significant decrease in IGF-1. HCC mice group showed moderate expression of p53 protein. These results suggest that the molecular pathogenesis of HCC in mice involves reduction of serum level of IGF-1 and increased serum level of E-cadherin accompanied by dysregulation of p53 protein expression. HCC was also associated with reprogrammed metabolic profile shifted toward increased glycolysis and lipogenesis.     

The importance of E-cadherin binding partners to evaluate the pathogenicity of E-cadherin missense mutations associated to HDGC

In hereditary diffuse gastric cancer (HDGC), CDH1 germline gene alterations are causative events in 30% of the cases. In 20% of HDGC families, CDH1 germline mutations are of the missense type and the mutation carriers constitute a problem in terms of genetic counseling and surveillance. To access the pathogenic relevance of missense mutations, we have previously developed an in vitro method to functionally characterize them. Pathogenic E-cadherin missense mutants fail to aggregate and become more invasive, in comparison with cells expressing the wild-type (WT) protein. Herein, our aim was to develop a complementary method to unravel the pathogenic significance of E-cadherin missense mutations. We used cells stably expressing WT E-cadherin and seven HDGC-associated mutations (five intracellular and two extracellular) and studied by proximity ligation assays (PLA) how these mutants bind to fundamental regulators of E-cadherin function and trafficking. We focused our attention on the interaction with: p120, β-catenin, PIPKIγ and Hakai. We showed that cytoplasmic E-cadherin mutations affect the interaction of one or more binding partners, compromising the E-cadherin stability at the plasma membrane and likely affecting the adhesion complex competence. In the present work, we demonstrated that the study of the interplay between E-cadherin and its binding partners, using PLA, is an easy, rapid, quantitative and highly reproducible technique that can be applied in routine labs to verify the pathogenicity of E-cadherin missense mutants for HDGC diagnosis, especially those located in the intracellular domain of the protein.     

High-Grade Non-Hodgkin's Lymphoma Stage I: A retrospective study of treatment, outcome and prognostic factors in 213 patients

In a retrospective study of 213 patients with high-grade non-Hodgkin's lymphomas clinical stage I, diagnosed 1985-1990, pretreatment prognostic variables and result of treatment were analysed. The median age of the patients was 67 years. Treatment consisted of radiotherapy in 61%, chemotherapy (10%) chemotherapy followed by radiotherapy (23%) and surgery alone (5%) of the patients. Complete response was achieved in 89% of the patients with estimated relapse-free survival at 5 years of 73%. Relative 5-year survival of all patients was 73%. After chemotherapy followed by radiotherapy the relapse rate was 15% compared with 29% after radiotherapy only. The 5-year relative survival differed between 58% and 74% in the treatment groups. Age, sex, nodal versus extranodal lymphoma, systemic symptoms, bulk of tumor and level of serum lactic dehydrogenase (s-LDH) were analysed as prognostic factors. In multivariate variate analysis, only age 65 years or older and elevated s-LDH were significant independent adverse prognostic factors.     

Regulatory effects of deoxycholic acid, a component of the anti-inflammatory traditional Chinese medicine Niuhuang, on human leukocyte response to chemoattractants

Niuhuang is a commonly used Chinese traditional medicine with immunoregulatory and anti-inflammatory properties. Deoxycholic acid (DCA) is a major active constituent of Niuhuang. The reaction of human leukocytes to chemoattractants is an important part of the host immune response and also plays a crucial role in the development of inflammation. We, therefore, investigated the in vitro effects of DCA on human monocyte and neutrophil responses to classic chemoattractants [fMet-Leu-Phe (fMLP), complement fraction 5a (C5a)], CC chemokine [monocyte chemoattractant protein-1 (MCP-1/CCL2)], and/or CXC chemokines [stromal cell-derived factor-1 (SDF-1alpha/CXCL12), interleukin-8 (IL-8/CXCL8)]. The results showed that DCA significantly inhibited fMLP-induced monocyte and neutrophil chemotaxis and calcium mobilization, and also blocked the binding of [3H]fMLP and anti-formyl peptide receptor (FPR) monoclonal antibodies (mAb) to the cells. The inhibitory effects of DCA on calcium mobilization and anti-FPR-mAb binding to the receptor could be abrogated by washing DCA out of the cell suspension, suggesting that DCA blocked fMLP receptors via a steric hindrance mechanism, not via receptor internalization. DCA had no significant inhibitory effects on MCP-1-, SDF-1alpha-, or C5a-induced monocyte function, or C5a- or IL-8-induced neutrophil function. Taken together, our experimental results suggest that blockade of fMLP receptors may contribute to the anti-inflammatory effects of traditional medicine containing DCA.     

Morphine glucuronide-to-morphine plasma ratios are unaffected by the UGT2B7 H268Y and UGT1A1*28 polymorphisms in cancer patients on chronic morphine therapy

OBJECTIVE: UDP-glucuronosyltransferase (UGT) 2B7 is the major UGT isoform responsible for the 3- and 6-glucuronidation of morphine in humans. Studies in rats have indicated that UGT1A1 may also contribute to the formation of morphine 3-glucuronide (M3G). Our objective was to investigate whether the UGT2B7 H268Y and UGT1A1*28 polymorphisms contribute to the variability in morphine glucuronide-to-morphine plasma ratios among cancer patients undergoing analgesic therapy with morphine. METHODS: Seventy patients with normal hepatic and renal function using slow-release morphine to relieve cancer pain were included. UGT2B7 genotyping was performed using restriction enzyme analysis of polymerase chain reaction (PCR)-amplified DNA fragments. Wild-type and variant alleles of the UGT1A1 gene were identified using sizing of PCR-amplified fragments. Morphine 6-glucuronide (M6G)/morphine, M3G/morphine, and M3G/M6G plasma ratios were compared between genotypes. RESULTS: The M3G/morphine, M6G/morphine, and M3G/M6G plasma ratios varied 16-, 42-, and sevenfold, respectively, among individuals. No statistically significant differences in plasma ratios were found between individuals possessing UGT2B7 H/H ( n=20), H/Y ( n=30), or Y/Y ( n=20) genotypes. Five patients were homozygous for the UGT1A1 TA(7) allele, which is associated with reduced UGT1A1 gene expression. However, the mean M3G/M6G and M3G/morphine plasma ratios in TA(7) homozygous subjects did not differ significantly from those of heterozygous or homozygous wild-type (TA(6)) individuals. CONCLUSION: The UGT2B7 H268Y polymorphism cannot account for the considerable variation in glucuronide-to-morphine ratios in cancer patients. Moreover, the contribution of UGT1A1 to the formation of M3G appears to be of minor biological significance, at least in a UGT2B7 background.     

Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and chlorinated paraffins (CPs) in rats-testing interactions and mechanisms for thyroid hormone effects

The effects of the polybrominated diphenyl ether (PBDE) congener 2,2'4, 4'-tetrabromodiphenylether (DE-47), and technical preparations of polychlorinated biphenyls (PCBs; Aroclor 1254) and chlorinated paraffins (CPs; Witaclor 171P) on thyroid hormone (TH) levels were examined in rats. To study possible interactive effects, also combinations of the three compounds were used. Thus, female Sprague-Dawley rats, 7 weeks old, were treated with approximately isomolar doses (ca. 30 micromol/kg bw per day) of DE-47 (6.0 mg/kg per day), Aroclor 1254 (4.0 mg/kg per day) and Witaclor 171P (6.8 mg/kg per day), alone or in combinations, daily for 14 days by gastric intubation. DE-47 was also administered in a higher (18 mg/kg per day) and lower (1.0 mg/kg per day) dose. In order to test possible mechanisms behind the TH effects, microsomal enzyme (cytochrome P-450 isozymes and uridine diphosphoglucuronyl transferase-UDPGT) activity (indicating both metabolic activation and/or biliary clearance), ex vivo-binding of 125I-T4 to plasma proteins (suggesting effects on peripheral TH transport) and light microscope morphology of the thyroid gland were studied. The observed degree of TH reduction after Aroclor 1254 and DE-47 exposure corresponded with a decrease in the ex vivo binding of 125I-T4 to the plasma TH-transporter transthyretin (TTR), and with induction of the microsomal phase I enzymes (ethoxy- and methoxy-resorufin dealkylases, EROD and MROD). The phase II enzyme UDPGT was also elevated, but only moderately. The thyroid morphology showed an activation of the epithelia, but no degenerative alternations, that was correlated to exposure to Aroclor 1254. In our model, the observed effects match the hypothesis that the T4 decrease is chiefly due to disturbances in serum transport, caused by binding of in vivo-formed Aroclor 1254 and DE-47 metabolites to TTR. However, decreased plasma TH levels due to increased glucuronidation activity may also be of some importance. The thyroid gland hyperactivity is probably a feed-back consequence of the T4 decrease, in spite of the lack of TSH alterations. In the mixed DE-47 and Witaclor 171P group synergistic effects were indicated on free T4 (FT4) and EROD induction levels, results that may suggest that such effects should be considered in risk assessment of mixtures of persistent organohalogens.     

The addition of locust bean gum but not water delayed the gastric emptying rate of a nutrient semisolid meal in healthy subjects

Background  

Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal.