Telemicrobiology: feasibility study.

BACKGROUND: Rural hospitals generally lack staffing with infectious disease specialists or pathologists. Without on-site pathologists, the range of microbiology services offered by clinical laboratories may be limited as well. OBJECTIVE: To study the feasibility of using static-image telepathology to evaluate Gram stains of microbiologic preparations. MATERIALS AND METHODS: In this retrospective feasibility study, three pathologists evaluated Gram stains of slides from 50 cases by two viewing modalities: static-image telepathology and conventional light microscopy. Digital video images of slides were captured at two magnifications (using 40x and 100x objective lenses) at 1024 x 768 x 24-bit color and transmitted over standard telephone lines at 14,400 kbps. Pathology reports and culture results served as "truth diagnoses." Categories of interpretations were correct, minor discrepancy, or major discrepancy with regard to the implications for patient care. RESULTS: The diagnostic accuracy of video image readings and conventional light microscopy readings were nearly identical, with no statistically significant differences in the performances of specialty and nonspecialty pathologists (P > 0.05). The mean accuracies of readings of the video images and light microscopy images were 95.3% and 95.4%, respectively. Taking into account the time required by a referring pathologist to capture video digital images, telemicrobiology was somewhat less efficient than conventional light microscopy. CONCLUSIONS: Pathologists can accurately evaluate digital video images of preselected fields on Gram-stained slides. In clinical practice, however, a limiting factor may be the availability of local personnel qualified to select the microscopic fields for evaluation by telepathologists. The adequacy of the video images suggests that telepathology may also be used for remote supervision of quality assurance programs in microbiology laboratories, as well as for remote proficiency training of laboratory personnel.

Diagnostic accuracy of an international static-imaging telepathology consultation service.

Static-image and dynamic- (real-time) image telepathology are competing technologies. Although some studies suggest that the diagnostic accuracy of the dynamic-image telepathology approaches the accuracy of light microscopy, few reports have documented the diagnostic accuracy of static-image telepathology as used in the setting of an actual surgical pathology consultation practice. We report the results of an analysis of 171 telepathology consultation cases submitted to the Arizona-International Telemedicine Network (AITN). Digital images were submitted by pathologists from six participating institutions in Arizona, Mexico, and China. Telepathologists could render a telepathology diagnosis (TP) or defer rendering a diagnosis to obtain additional video images, glass slides for detailed analysis, or to obtain tissue blocks for special studies such as immunohistochemistry. The telepathologists rendered diagnoses for 144 cases and deferred 27 cases. Two pathologists retrospectively evaluated-glass slides from each case and rendered a consensus glass slide (GS) "truth" diagnosis. There was 88.2% concordance between TP and GS diagnoses (127 of 144 diagnoses). Concordance of 96.5% was achieved for clinically important diagnoses (139 of 144 diagnoses). Telepathologists deferred making a diagnosis to obtain glass slides for conventional light microscopy in 14 cases (8.1%) and for results of immunohistochemistry studies in 13 cases (7.6%). Thus, correct diagnoses were rendered by static-image telepathology in 127 of 171 cases (74.3%) at the time of telepathology diagnostic sessions. Inappropriate field selection and sampling biases of referring pathologists, as well as a tendency of static-image telepathologists to underestimate the complexity of some cases, may reduce the value of consultations based on the viewing of static images.

BHA (2(3)-tert-butyl-4-hydroxyanisole)-mediated modulation of acetaminophen phase II metabolism in vivo in Fisher 344 rats.

Adult male Fisher 344 rats (190-220 g), were given an intravenous dose (10 mg/rat) of BHA. Pretreated and control rats received an intravenous dose of [G-3H] acetaminophen (25 mg/rat). Bile was collected prior to dosing and for 5-6 hours after dosing at varying time intervals. Separate aliquots of 0.2 ml were incubated with beta-glucuronidase and sulfatase, respectively. These incubation mixtures were then extracted and analyzed by reverse phase HPLC. In all cases control animals showed a greater deceleration in the biliary excretion of the water soluble metabolites when compared with pretreated animals. Increases in both glucuronide and sulfate elimination processes are assumed to be contributory, in part, to the overall effect of BHA on acetaminophen metabolism.

Insulin secretion and glucose uptake by isolated islets of the hamster. Effect of insulin, proinsulin and C-peptide.

Isolated pancreatic islets of normal hamsters were perifused either in a closed or in a open system. When the buffer was recirculated and the endogenous insulin was allowed to accumulate, the islets secreted significantly less insulin than when the system was open and the endogenous insulin was washed away. The addition of monocomponent insulin or of proinsulin to the perifusion buffer significantly decreased insulin secretion. The inhibitory action of proinsulin was significantly greater than that of monocomponent insulin. C peptide had no effect. When pancreatic islets were incubated in a fixed volume of stationary buffer containing unlabeled glucose (1.0 mg or 3.0 mg/ml) and glucose-U-14C (1.0 muC/ml), the amount of insulin secreted and the 14CO2 produced by each islet decreased progressively as the number of islets in the sample increased. Under these conditions, the concentration of insulin required to inhibit insulin secretion increased with the concentration of glucose in the medium. Proinsulin did not alter the incorporation of leucine-4.5(-3). H into total extractable insulin (insulin + proinsulin). Thus, insulin and proinsulin appear to inhibit insulin release, but not insulin synthesis.