Standardization of a cone beam computed tomography machine in evaluating bone density: a novel approach.

BACKGROUND: Advent of cone beam computed tomography (CBCT) in dentistry has brought us to a new era of precise imaging. Radiographic evaluation of a CBCT image is more informational when compared to CT. The density measurements in CBCT images are based on greyscale values, which are more accurate in CT and these values are inconsistent across various CBCT machines. Hence, we aim at standardizing a single CBCT scanner to evaluate or determine tissue density from the greyscale values. METHODS: A total of 8 halves of undamaged, dry goat mandibles are included in the study. Scans of the bone are obtained using the KODAK CBCT unit and the PHILLIPS CT machine respectively. Densities are evaluated at 96 points on both the CT scans and the CBCT scans, respectively, using the Radiant Dicom viewer. The obtained data is entered into the excel spreadsheet and subjected to statistical analysis. RESULTS: The greyscale values are obtained from each of the CBCT scans. Hounsfield units are calculated from CT images coinciding with the same points on CBCT scans. The collected data is subjected to linear regression analysis and an equation is derived to determine Hounsfield units (calculated HU units) from greyscale values of CBCT images. We found no significant difference between the mean original HU units and the mean calculated HU units, thus making the equation reliable for calculating HU units from CBCT greyscale values. CONCLUSIONS: Our results conclude that the technique was effective in calculating the Original density of tissues using grey standards of CBCT scans.

Awareness of medical students in a medical college in Mangalore, Karnataka, India concerning infection prevention practices.

BACKGROUND: Healthcare-associated infections (HCAIs) are an important public health problem. It is estimated that approximately 1 out of every 20 hospitalized patients will contract an HCAI. The risk is substantial not only to patients but also to healthcare workers, who may contract deadly blood-borne infectious diseases. Hence, it is essential for healthcare professionals to have adequate knowledge regarding infection prevention practices (IPPs) to reduce the burden of these illnesses among patients seeking care. METHODS: This cross-sectional study was conducted among 268 medical students at Kasturba Medical College, Mangalore. Information regarding important IPPs such as hand hygiene (HH), needle-stick injuries (NSIs), and standard precautions (SPs) was collected using a semi-structured questionnaire. The collected information was analyzed using SPSS v.11. Fisher's exact test was used to test the association between variables of interest. RESULTS: Overall, knowledge levels regarding HH were low in aspects such as healthcare workers' hands as sources of infection (40%) and the minimum time needed to apply hand rubs (45.7%), whereas knowledge levels were high in aspects such as indications for using HH. Regarding NSI prevention, knowledge levels were low in aspects such as activities with the highest NSI risk (56%). However, knowledge levels were high in relation to SPs. CONCLUSION: The knowledge levels regarding infection practices were not adequate among the participants, particularly in the case of hand hygiene methods. Other important aspects, such as needle-stick injuries and use of standard precautions, were better understood, although many aspects still require improvement. These findings suggest the need to consider strengthening the training related to IPPs as a separate entity in the existing curriculum.

Gastrointestinal disturbances in diabetes.

Gastrointestinal disorders are common in patients with diabetes mellitus. As many as 75% of patients visiting diabetes clinics will report significant gastrointestinal (GI) symptoms. The symptom complex experienced may vary widely. Many patients go undiagnosed and undertreated. Patients with a history of retinopathy, nephropathy, or neuropathy should be presumed to have GI abnormalities until proven otherwise. The workup should start with a thorough patient history and appropriate laboratory, radiographic, and GI testing. In addition to pharmacologic therapy, glycemic control and dietary manipulation play an important role in managing GI disorders in people with diabetes.

Differential effects of metformin and troglitazone on cardiovascular risk factors in patients with type 2 diabetes.

OBJECTIVE: Traditional cardiovascular risk factors (CVRF) only partly explain the excessive risk of cardiovascular disease in patients with type 2 diabetes. There is now an increasing appreciation for many novel CVRF that occur largely as a result of insulin resistance and hyperinsulinemia. Therefore, we investigated whether diabetes medications that vary in their mechanism of action and ability to reduce insulin resistance may differ in their effects on both traditional and novel CVRF. RESEARCH DESIGN AND METHODS: We compared the addition of metformin or troglitazone therapy on CVRF in 22 subjects with type 2 diabetes who remained in poor glycemic control (with HbA1c >8.5%) while taking glyburide 10 mg twice daily. Subjects were initially randomized to either metformin 850 mg once daily or troglitazone 200 mg once daily. Both medications were then titrated upward as needed to achieve fasting plasma glucose <120 mg/dl. Measures of glucose control, insulin resistance, and CVRF (blood pressure, lipids, plasminogen activator inhibitor-1, C-reactive protein, fibrinogen, and small dense LDL) were assessed both before and after therapy. RESULTS: After 4 months of treatment, both metformin and troglitazone led to similar decreases in fasting plasma glucose and HbA1c. The reduction in insulin resistance determined by hyperinsulinemic-euglycemic clamp was nearly twofold greater with troglitazone than metformin. Metformin did not induce significant changes in blood pressure, LDL cholesterol, LDL size, HDL cholesterol, triglycerides, or plasminogen activator inhibitor-1. However, C-reactive protein did decrease by 33% (6 +/- 1 to 4 +/- 1 mg/l; P < 0.01) [corrected]. Troglitazone therapy was associated with increases in LDL size (26.21 +/- 0.22 to 26.56 +/- 0.25 nm; P=0.04) and HDL cholesterol (33 +/- 3 to 36 +/- 3 mg/dl; P=0.05) and decreases in triglycerides (197 +/- 19 to 155 +/- 23 mg/dl; P=0.07) and C-reactive protein by 60% (8 +/- 3 to 3 +/- 1 mg/l, P < 0.01) [corrected]. CONCLUSIONS: For patients with type 2 diabetes in whom maximal sulfonylurea therapy failed, the addition of the insulin sensitizer troglitazone seemed to have greater benefits on several traditional and novel CVRF than metformin therapy. These differences were not related to glycemic improvement but reflected, in part, the greater reduction in insulin resistance obtained with addition of troglitazone. These data suggest that medications that more effectively address this underlying metabolic defect may be more beneficial in reducing cardiovascular risk in type 2 diabetes.

Regulation of glucose transport and insulin signaling by troglitazone or metformin in adipose tissue of type 2 diabetic subjects.

Type 2 diabetic subjects failing glyburide therapy were randomized to receive additional therapy with either metformin (2,550 mg/day) or troglitazone (600 mg/day) for 3-4 months. Biopsies of subcutaneous abdominal adipose tissue were obtained before and after therapy. Glycemic control was similar with both treatments. Metformin treatment increased insulin-stimulated whole-body glucose disposal rates by 20% (P < 0.05); the response to troglitazone was greater (44% increase, P < 0.01 vs. baseline, P < 0.05 vs. metformin). Troglitazone-treated subjects displayed a tendency toward weight gain (5 +/- 2 kg, P < 0.05), increased adipocyte size, and increased serum leptin levels. Metformin-treated subjects were weight-stable, with unchanged leptin levels and reduced adipocyte size (to 84 +/- 4% of control, P < 0.005). Glucose transport in isolated adipocytes from metformin-treated subjects was unaltered from pretreatment. Glucose transport in both the absence (321 +/- 134% of pre-Rx, P < 0.05) and presence of insulin (418 +/- 161%, P < 0.05) was elevated after troglitazone treatment. Metformin treatment had no effect on adipocyte content of GLUT1 or GLUT4 proteins. After troglitazone treatment, GLUT4 protein expression was increased twofold (202 +/- 42%, P < 0.05). Insulin-stimulated serine phosphorylation of Akt was augmented after troglitazone (170 +/- 34% of pre-Rx response, P < 0.05) treatment and unchanged by metformin. We conclude that the ability of troglitazone to upregulate adipocyte glucose transport, GLUT4 expression, and insulin signaling can contribute to its greater effect on whole-body glucose disposal.

Erectile dysfunction and diabetes.

Erectile dysfunction (ED) has been the most neglected complication of diabetes. It is a common abnormality that affects more than 20 million American men. The prevalence of ED in the general population between the ages of 40 to 70 years is 52%. In men with diabetes, it ranges from 35% to 75%, and occurs at an earlier age. There have been several advances in the understanding of the physiologic and biochemical mechanisms controlling penile erections. Improved techniques in diagnoses and treatment of impotence have given the male with diabetes some hope in the management of this prevalent and emotionally disturbing complication.