Diagnosis goes digital.

Accurate images of the craniofacial region are critical for the development of an orthodontic diagnosis and treatment plan. The NewTom QR 9000 Volume Scanner (QR s.r.l., Verona, Italy) represents a significant advance in imaging capabilities for dentistry and orthodontics. This new-generation scanner uses computed tomography technology to provide a complete 3D view of the maxilla and mandible with relatively high resolution and low radiation exposure to patients. This article discusses some technical aspects of this new scanner and its possible orthodontic uses.     

Chronic vitamin E treatment prevents defective endothelium-dependent relaxation in diabetic rat aorta

Summary We examined the effect in rats of 2 months of streptozotocin-induced diabetes mellitus on relaxation and contraction of aortas in vitro. A further diabetic group was treated from time of diabetes induction with a 1% dietary supplement of vitamin E. Diabetes caused a 26.5% deficit (p<0.001) in maximum endothelium-dependent relaxation to acetylcholine in phenylephrine-precontracted aortas. This was 64.3% attenuated (p<0.01) by vitamin E treatment; maximum relaxation was not significantly altered compared to non-diabetic rats. Vitamin E treatment of non-diabetic rats did not significantly affect acetylcholine-induced relaxation. Diabetes or treatment did not significantly alter acetylcholine sensitivity. Endothelium-independent relaxation response to glyceryl trinitrate was not affected by diabetes or vitamin E treatment, indicating that vascular smooth muscle responses to nitric oxide remained unaltered. There was a 35.4% reduction in the maximum contractile response to phenylephrine with diabetes (p<0.05) which was unaffected by vitamin E treatment. The data suggest that the chronic deficit in nitric oxide-mediated endothelium-dependent relaxation in diabetes depends largely upon excess activity of reactive oxygen species. Treatment with vitamin E to increase free radical scavenging specifically protected vascular endothelium although it had no effect on deficits in vascular smooth muscle contractile responses.Abbreviations NO Nitric oxide - ARI aldose reductase inhibitor - ACH acetylcholine - GTN glyceryl trinitrate - GSH reduced form of glutathione - EC₅₀ effective concentration for 50% of the maximal response     

Different mechanisms by which anti-DNA MoAbs bind to human endothelial cells and glomerular mesangial cells.

The mechanisms by which anti-DNA MoAbs derived from MRL-lpr/lpr mice, bind to human umbilical vein endothelial cells (HUVEC) and glomerular mesangial cells were studied using a cellular ELISA. DNAse-treatment of either the MoAb or HUVEC followed by reconstitution with DNA and/or histones was performed to determine whether DNA and histones mediated such binding. It was found that MoAb410 bound to HUVEC and mesangial cells in the form of preformed DNA/anti-DNA immune complex, and such binding was facilitated by histones. In contrast, MoAb 152 bound directly to cell membrane-associated DNA, and adding DNA to MoAb 152 reduced its cellular binding. DNA binds endothelial cell surface and histones enhance the binding of both MoAb 410 and MoAb 152 to HUVEC by increasing cell membrane-associated DNA. Finally, the degree of MoAb binding to HUVEC is critically influenced by the relative concentrations of antibody, DNA, and histones.     

Carcinoma of the body and tail of the pancreas.

Recently, several institutions have reported improved results in the treatment of patients with carcinoma of the head of the pancreas. In an attempt to determine whether similar trends could be demonstrated for patients with carcinoma of the body and tail of the pancreas, the records of all 113 patients with an adenocarcinoma of the body or tail of the pancreas treated at The Johns Hopkins Hospital between 1972 and 1989 were reviewed. The patients were divided into two groups: those diagnosed between 1972 and 1982 (41 patients) and those between 1983 and 1989 (72 patients). No significant differences in tumor stage were observed between the two groups. The proportion of patients who underwent surgery decreased from 68% to 47% (p = 0.02). The number of patients who had bypass operations (15% versus 17%) or pancreatic resection (5% versus 10%) was similar in the two groups, but the proportion of patients who underwent exploratory laparotomy with biopsy only decreased from 49% to 21% (p = 0.002). The postoperative 30-day mortality (7% versus 3%), postoperative morbidity (18% versus 21%), median survival (4 months versus 3 months), and the 1-year survival (8% versus 9%) did not differ significantly between the two groups. One patient survived for 6 years after resection, and another patient is still alive 3 years after resection. Thus, unlike adenocarcinoma of the head of the pancreas, it appears that treatment results for patients with adenocarcinoma of the body or tail of the pancreas have not improved in recent years, the only change being a decreased need for exploratory laparotomy with biopsy only.     

Adherence of Staphylococcus aureus to cultures of human peritoneal mesothelial cells

Strains of Staphylococcus aureus, isolated from the effluentof patients with peritonitis on CAPD (continuous ambulatoryperitoneal dialysis), adhered well to both cultured human mesothelialcells and to fibronectin, but not to laminin or gelatin. Mesothelialcells grown in medium M199 exhibited more surface fibronectincompared to cells grown in MEM-Dval and demonstrated higherlevels of S. aureus adherence. Soluble fibronectin concentrations up to lOµg/ml increasedthe adherence of S. aureusto cultured mesothelial cells. Thedose-response curve was consistent with the binding of fibronectinto a saturable receptor of apparent dissociation constant (K_D)= 1.7xlO^–10 M. This corresponds closely to the K_D (2xlO^–10M) of the staphylococcal fibronectin-binding protein. S. aureus adherence was increased following the preincubationof mesothelial cell monolayers with interleukin-1 and was maximalafter 6 h preincubation. Treating mesothelial cells with interferon-gammafor 48–72 h reduced the adherence of S. aureus.     

Altered angiotensin-II receptors in human hepatocellular and hepatic metastatic colon cancers.

OBJECTIVE: To characterize angiotensin-II receptor density and affinity in normal and cirrhotic livers and in hepatocellular and metastatic colorectal cancer. SUMMARY BACKGROUND DATA: Several studies have indicated a possible beneficial effect of angiotensin-II as a biologic response modifier in the treatment of hepatic or metastatic colon cancer. This is based on evidence that angiotensin-II will cause a selective increase in arterial vasoconstriction in normal liver compared with tumor. METHODS: Human hepatoma (5), metastatic colon (10), or cirrhotic (3) liver was obtained. Non-tumor-bearing regions served as normal liver. Angiotensin-II receptor binding was determined on membranes with 125I-angiotensin-II and in situ studies were performed using the biotin-avidin detection system. RESULTS: Angiotensin-II receptor density was markedly down-regulated in tumor compared with normal or cirrhotic liver. CONCLUSIONS: A loss of angiotensin-II receptors occurs on the neovasculature of hepatic tumors.     

HERPES SIMPLEX VIRUS ENCEPHALITIS: PROBLEMS IN DIAGNOSIS

Six children aged 13 days to nine years with herpes simplex encephalitis (HSE) are presented. Institution of appropriate antiviral treatment was later than six days in three cases; original diagnosis in these cases were post-traumatic epilepsy, bacterial meningitis and febrile convulsion. Initially pyrexia was absent in two cases and cranial CT was normal in two cases. Encephalitic changes were observed on the EEGs of five children. Diagnosis was confirmed by paired serological titres, brain biopsy, vesicle culture and CSF titres. The outcome for all six children was poor. HSE should always be considered in children presenting with focal seizures, even when apyrexial and with normal CT findings. In such situations, saving CSF for antibody titres or antigen identification should be routine practice. Treatment with acyclovir is justified before precise virological diagnosis has been established.