Osteosarcoma of the temporomandibular joint: report of 2 cases

The aim of this article is to report 2 cases of osteosarcoma of the mandibular condyle, a rare pathological condition, and to emphasize and discuss the usefulness of different imaging modalities in the diagnosis and evaluation of osteosarcoma of the temporomandibular joint. In our assessment of the different imaging modalities, we found that 2-dimensional computed tomograms provide excellent detection of tumor calcification, cortical involvement, and in most instances, soft tissue and intramedullary extension, whereas 3-dimensional computed tomography vascular protocol can help to define the extension of the lesion, improving the visualization of the lesion's relationship to the adjacent anatomical structures. Magnetic resonance imaging is more effective in demonstrating the intramedullary and extraosseous tumor components on T2 weighted images. Because metastasis from body tumors to the maxillofacial region occurs occasionally, it is useful to examine the oral cavity when symptoms first appear and devote special attention to the subtle changes that may indicate early metastatic involvement.     

The effect of oestrogen and testosterone on the urethral seam of the developing male mouse genital tubercle

OBJECTIVES: To describe the effects of exogenous oestrogens and androgens on urethral formation in the mouse, as the development of the mouse and human urethra have significant similarities, and understanding normal male urethral development may help to identify the causes of abnormal development, e.g. hypospadias. MATERIALS AND METHODS: Timed-pregnant C57/6 mice were exposed to synthetic oestrogens and androgens. The morphology of the genital tubercles was examined histologically and with three-dimensional computer reconstruction. Specific attention was focused on the developing urethral seam. RESULTS: Microscopic serial analysis confirmed the presence of an arrest in seam formation in about half of oestrogen-treated male fetuses. In contrast, there was acceleration of urethral fold fusion and a longer urethral tube in those treated with androgens. Oestrogen-treated fetuses had a thin periurethral spongiosa, in contrast to androgen-treated fetuses which developed a thicker periurethral spongiosa. The effect of oestrogens on seam area formation did not depend on the dose, but in contrast, in the androgen-treated fetuses it was. CONCLUSION: Oestrogens and androgens have a direct effect on the fusion of the urethral fold that leads to seam formation. Normal urethral development depends on the delicate balance of these complementary hormones.     

Antinociceptive and antiedematogenic properties and acute toxicity of Tabebuia avellanedae Lor. ex Griseb. inner bark aqueous extract

Background

The search for an optimal experimental model in pharmacology is recently focused on (mini)pigs as they seem not only to be an alternative source of cells and tissues for xenotherapy but also an alternative species for studies on drug metabolism in man due to similarities between (mini) pig and human drug metabolizing systems. The purpose of this work is to characterize minipig liver microsomal cytochromes P450 (CYPs) by comparing their N-terminal sequences with corresponding human orthologs.

Results

The microsomal CYPs exhibit similar activities to their human orthologous enzymes (CYP3A4, nifedipine oxidation; 2A6, coumarin 7-hydroxylation; 2D6, bufuralol 1'-hydroxylation; 2E1, p-nitrophenol hydroxylation; and 2C9, tolbutamide hydroxylation). Specific minipig CYP (2A, 2C and 3A) enzymes were partially purified and proteins identified by immunostaining (using antibodies against the respective human CYPs) were used for N-terminal amino acid sequencing. From comparisons, it can be concluded that the sequence of the first 20 amino acids at the N-terminus of minipig CYP2A is highly similar to human CYP2A6 (70% identity). The N-terminal sequence of CYP2C shared about 50% similarity with human 2C9. The results on the minipig liver microsomal CYP3A yielded identical data with those obtained for amino acid sequences of the pig CYP3A29 showing 60% identity with human CYP3A4.

Conclusions

Thus, our results further support the view that minipigs may serve as model animals in pharmacological/toxicological studies with substrates of human CYP enzymes, namely, of the CYP3A and CYP2A forms.     

Treatment of liver metastases with moderate peritoneal carcinomatosis by hepatectomy and cytoreductive surgery followed by immediate post-operative intraperitoneal chemotherapy: feasibility and preliminary results

BACKGROUND/AIMS: Peritoneal carcinomatosis (PC) discovered during hepatectomy is usually a contraindication to resection. A potentially efficient treatment of PC is the resection of the macroscopic disease and the treatment of the residual microscopic disease with immediate post-operative intraperitoneal chemotherapy (IPIC) (before the entrapment of cancer cells inside the fibrin deposit which rapidly cover the injured tissues). Feasibility and survival results of this treatment, combined with major hepatectomy, have never been evaluated. The purpose of this study is to report tolerance and preliminary results in patients with liver metastases synchronous to moderate PC, treated with hepatectomy, complete cytoreductive surgery, and IPIC. METHODOLOGY: Twelve patients with liver metastases and moderate PC from miscellaneous origins, underwent: 1) hepatectomy (9 of them were major hepatectomies); 2) complete cytoreductive surgery of the PC resecting between 20 and 150 nodules; and, 3) IPIC, for 5 days, according to histology. RESULTS: There was no mortality. Morbidity was mainly due to four transient biliary leakages (33%) and there was no systemic complication due to the chemotherapy. After a median follow-up of 14.4 months, there was no detectable recurrence of the PC. Preliminary results concerning survival are promising with 7 patients without recurrent disease. CONCLUSIONS: When a minimal or moderate PC is discovered during laparotomy for liver resection of metastases, the combination of hepatectomy with complete cytoreductive surgery of the peritoneal disease, followed with IPIC is logical and feasible. This aggressive treatment is well tolerated although the frequency of biliary leakage seems to be higher than that after standard hepatectomy. No recurrence of the peritoneal disease was detected and survival results are very promising.     

Chronic hepatitis C infection: influence of the viral load, genotypes, and GBV-C/HGV coinfection on the severity of the disease in a Brazilian population

The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV-C virus (GBV-C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18-72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV-C/HGV RNA estimations were carried out by double-nested polymerase chain reaction (PCR) using primers from the 5'-untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5'-UTR primers and by PCR with type-specific 5'-UTR primers. GBV-C/HGV-RNA genotypes were determined by RFLP with specific 5'-UTR primers and phylogenetic trees were constructed using the Neighbour-Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 10(6) genome equivalents per millilitre (range 10(4)-10(9)/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV-C/HGV-RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV-C/HGV.     

Effects of fibroblast growth factor-4 (k-FGF) on long-term cultures of human bone marrow cells

Fibroblast growth factor-4 (FGF-4), a highly mitogenic protein encoded by the k-fgf/hst oncogene, stimulates the growth of a variety of cells of mesenchymal and neuroectodermal origin. Addition of FGF-4 to human long-term bone marrow cultures increased both the cell density of the stromal layer and the number of hematopoietic colony forming cells in the cultures in a dose-dependent manner. Hematopoiesis in the stromal layer persisted for up to 8 months. Erythropoiesis was maintained for up to 4 weeks, but granulocytes were the predominant nonadherent cell type. Cultures treated with FGF had increased numbers of monocytes compared with control cultures and some CD14+, CD45+ monocytes could still be detected after 8 months of continuous culture. The addition of the growth factor increased the rate of growth of the stromal layer and appeared to delay its senescence. Subcultures made in the presence of FGF-4 had up to 10-fold increases in plating efficiency and grew as relatively uniform monolayers. These subcultures retained the capacity to support hematopoiesis for several months, while untreated subcultures, made without FGF-4, grew erratically and generally lost the capacity to support hematopoiesis within 4 to 6 weeks. The improved growth after subculture greatly enhanced the reliability of limit- dilution assays of multipotential hematopoietic stem cells that use stromal cell monolayers. The primary effect of FGF-4 appeared to be on the stromal cells of the long-term bone marrow cultures, but a direct effect on hematopoietic progenitors could not be ruled out.     

Cost of Tuberculosis Diagnosis and Treatment in Patients with HIV: A Systematic Literature Review

Objectives

To summarize the costs of tuberculosis (TB) diagnosis and treatment in human immunodeficiency virus (HIV)-infected patients and to assess the methodological quality of these studies.

Effect of light-curing unit and adhesive system on marginal adaptation of class v composite restorations

The aim of this study was to evaluate the effect of light-curing units (LED or halogen) on the marginal adaptation of composite restorations performed with etch-and-rinse and self-etching adhesive. Class V cavities were prepared on bovine teeth with the gingival margin on dentin and the incisal margin on enamel. The cavities were restored with a micro-hybrid resin composite using an etch-and-rinse (Single Bond 2--SB) or a self-etching adhesive (Clearfil SE Bond--CL). The light-activations were performed using halogen lamp (Optilux 501--QTH) or second-generation light-emitting diode (Radii-Cal--LED) (n = 10). After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed under scanning electronic microscopy with 500x of magnification. The greatest gap width at each margin was recorded. Data were submitted to Mann-Whitney and Wilcoxon tests (a = 0.05). SB and CL showed similar behavior of enamel margins when the light-activations were performed with QTH. The same was observed for dentin margins with LED. When the LED was used, higher gap measurements at enamel margins were observed with CL, while higher gap values in dentin were observed for SB within QTH. No significant difference between substrates was found when CL was used. However, SB had significantly higher gap measurements in dentin. The light-curing unit seems to affect the marginal adaptation of resin composite restorations. However this effect was dependent on the adhesive and the location of the margin.     

Effect of antioxidant supplementation on the auditory threshold in sensorineural hearing loss: a meta-analysis

Introduction

Hearing loss is conceptualized as any impairment of the ability to hear and/or detect speech or environment sounds, regardless of cause, type, or degree. It may occur at different stages of life; during pregnancy or childbirth, in childhood, adulthood or old age. It should be noted that aging is the most common cause of sensorineural hearing loss followed by noise-induced hearing loss, and both are closely related to the formation of reactive oxygen species. Dietary antioxidant supplementation has been employed as a therapeutic strategy to prevent and/or delay the risks of major human diseases.