Sterilisation patterns in dental practices in Singapore

A survey to find out the standard of sterilisation of dental equipment was conducted via a questionnaire sent out to all Division I dental surgeons in Singapore. Questions asked determined the main methods of sterilisation/disinfection of hand instruments, air rotor and air motor handpieces, burs, salivary ejectors, ultrasonic scaling tips, and the use of disposable needles, local anesthetic, carpules, and gloves. Results indicated that while most respondents sterilised or disinfected various instruments, there was an apparent misconception that sterilisation and disinfection were the same thing. The majority used boiling with water or cold chemical disinfection. Most respondents were willing to treat patients with known histories of hepatitis B but would refer patients with histories of Acquired Immune Deficiency Syndrome (AIDS).     

Histological studies of surgically resected hepatocellular carcinoma following combined radiotherapy and hyperthermia.

Four cases of hepatocellular carcinoma (HCC) were surgically resected following combined radiotherapy (RT) and hyperthermia (HT). Complete necrosis of the tumor without viable tumor cell was found in one case and extensive tumor necrosis was observed in the other three cases; the percentage of necrosis in the specimens were 40%, 70%, and 80%, respectively. Histologic assessment showed mainly coagulative necrosis in the tumor with focal liquefactive necrosis. Cystic dilatation of sinusoids was observed in both tumor and nontumorous normal liver tissue. Other changes in normal liver tissue were unremarkable except for infiltration of inflammatory cells, fatty change, and proliferation of the bile ducts which can usually be seen beyond the area where any space occupying lesions are present. It is concluded that combined radiotherapy and hyperthermia can significantly induce coagulative necrosis of hepatocellular carcinoma with nonsignificant minimal histologic changes in adjacent nontumorous liver tissue.     

Differential inotropic effects of flosequinan in ventricular muscle from normal ferrets versus patients with end-stage heart failure.

1. In right ventricular papillary muscles from control ferrets, flosequinan (10(-7)-10(-4) M) produced a concentration-dependent positive inotropic effect (10(-5) M = 153 +/- 24, 10(-4) M = 198 +/- 44% increase in isometric tension; control tension = 100%; n = 11) associated with a corresponding increase in amplitude of the intracellular Ca2+ ([Ca2+]i) transient recorded with aequorin (10(-5) M = 133 +/- 11, 10(-4) M = 187 +/- 36% increase in [Ca2+]i transient; n = 11). 2. The positive inotropic effect of flosequinan in control ferret ventricular muscle was neither blocked by propranolol (6 x 10(-7) M), nor associated with the abbreviation of the [Ca2+]i transient and contraction that is typical of catecholamines. 3. Neither flosequinan (n = 12) nor BTS 53 554, its sulphone metabolite (n = 6) produced a positive inotropic effect or altered the time course of contraction in myocardium from the hearts of patients with end-stage failure. 4. In contrast to milrinone, which produces a positive inotropic effect via phosphodiesterase inhibition, the unresponsiveness of myopathic human myocardium to flosequinan was not restored after intracellular adenosine 3':5'-cyclic monophosphate (cyclic AMP) levels were increased by prior treatment with forskolin (n = 13). 5. Taken together, these data indicate that flosequinan has a direct positive inotropic effect that is Ca(2+)-dependent, but independent of changes in intracellular cyclic AMP concentrations. 6. The positive inotropic effect may be species-dependent or altered by the presence of hypertrophy and/or heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)