The validity of telepathological frozen section diagnosis with ISDN-mediated remote microscopy

We investigated 109 randomly selected frozen section specimens from lung surgery patients in a retrospective blind mode using telepathology equipment. The telepathology system applied (HISTKOM) used one ISDN B-channel and telemicroscopy with a remotely operated robotic microscope. The performance of telepathological frozen section diagnosis was compared with that of conventional frozen section diagnosis. The false-positive rate achieved was identical for both methods. The sensitivity (P=0.03), but not the specificity, was significantly lower for the telepathological method. The time needed to establish a diagnosis with the remote microscope was too high; therefore, upgrading to multichannel technology is recommended. The quality of the images transmitted was judged to be sufficient by the pathologists involved in the study. In conclusion, with further technical improvements in telemicroscopy and additional experience in telepathology, remote diagnosis seems to be feasible.

European field tests with HISTKOM telepathology equipment

HISTKOM telemicroscopy equipment for telepathology is designed for the most challenging application in telepathology: intraoperational frozen section diagnosis. Adapted to this application, it is also excellently suited for all other telepathology modes requesting less sophisticated equipment. The technical concept and user interface are oriented to routine daily pathology. HISTKOM underwent heavy field-tests at several locations. The field-tests designs and the results of five of these are reported in this paper. Telepathology will exploit its advantages in networks hosting participants requesting and offering services. The solution of the interoperability problem caused by different equipment from different suppliers within such a network will be a major task, the solution for which is in progress. The new generation of HISTKOM equipment and software is designed in a modularized concept, allowing the integration of various hardware components from different manufacturers; thus special configurations can be realized easily. HISTKOM is offered as complete turnkey system, but can also be installed in yet existing configurations of the customer if they meet specifications.

Flow cytometric detection of specific gene expression in prokaryotic cells using in situ RT-PCR

Prokaryotic in situ RT-PCR was coupled with flow cytometry to detect mRNA transcripts of the toluene dioxygenase (todC1) gene in intact cells of the bacterium Pseudomonas putida F1. Recovery efficiency of fixed cells over the course of the entire in situ detection procedure was approximately 81% for both P. putida F1 and AC10R cells. It appeared that lysozyme treatment and PCR thermal cycling were the steps responsible for most of observed cell loss. Bacterial cells expressing the todC1 gene could be discriminated from negative control cells of the same size based on flow cytometrically-measured fluorescence and forward angle light scatter. According to flow cytometric analysis, the fluorescence intensity of positive cells was 4-5 times brighter than that of negative cells. The combination of flow cytometry and a prokaryotic in situ reverse transcription-PCR (RT-PCR) approach make possible the rapid detection and enumeration of functional (based on mRNA) populations of microbial cells.

Involvement of low-density lipoprotein receptor-related protein (LRP) in the clearance of factor VIII in von Willebrand factor-deficient mice

Factor VIII is tightly noncovalently linked to von Willebrand factor (vWF) in plasma with a stoichiometry of 1:50, and vWF deficiency results in secondary factor VIII deficiency, with accelerated clearance of factor VIII from the circulation. We used a murine model of severe von Willebrand disease (vWF knockout mice) to study the effect of a recombinant vWF/pro-vWF preparation (rpvWF) on factor VIII survival and to investigate whether low-density lipoprotein receptor-related protein (LRP) might be involved in the in vivo clearance of factor VIII in the absence of vWF. vWF-deficient mice received 70 U/kg rpvWF in the first series of experiments, and in a second series, 80 mg/kg receptor-associated protein (RAP) as a recombinant fusion protein to block the action of LRP. Factor VIII levels were measured at time 0, or 1 or 3 hours after administration of rpvWF or RAP. RAP induced a sustained rise in factor VIII levels comparable to that induced by rpvWF. In a third series, the preadministration of RAP resulted in a slower disappearance of factor VIII antigen (measured by an enzyme-linked immunosorbent assay specific for human factor VIII) after infusion of recombinant factor VIII. These findings suggest that the accelerated clearance of factor VIII seen in the absence of vWF may be a result of the involvement of LRP in factor VIII metabolism. (Blood. 2000;95:1703-1708)

Reliability of telepathology for frozen section service

One of the most promising applications of telepathology (pathology at a distance by electronic transmission of images in pathology) is frozen section diagnosis, especially because by means of this tool operations requiring an intraoperative histopathological diagnosis are feasible at hospitals without a pathologist on-site. For the introduction of this diagnostic tool into pathologist's daily practice the evidence of its diagnostic accuracy comparable to that of the conventional frozen section diagnosis is crucial. For this purpose the literature on the diagnostic accuracy of telepathological frozen section diagnosis was reviewed. In a metaanalysis these studies and reports, in which a total of more than 1290 cases had been examined, showed a slightly lower overall diagnostic accuracy (of the telepathological frozen section diagnosis) of about 0.91 than the conventional frozen section diagnosis with an average accuracy of about 0.98 found in an analysis of several studies (on frozen section diagnosis of different organs). This difference is at least predominantly caused by a higher rate of deferred and false negative frozen section diagnoses in the telepathological method, while the specificity of both methods, each more than 0.99 was not significantly different. In conclusion, the introduction of a telepathological frozen section diagnosis for hospitals without an acceptable access to a pathologist is justifiable already at the current state of the technological development especially when considering the advantages (time saving, reduction in costs) compared to the alternative of surgical interventions without access to an intraoperative diagnosis.

Technical aspects of telepathology with emphasis on future development

Pathology undergoes presently changes due to new developments in diagnostic opportunities and cost saving efforts in health care. Out of the wide field of telepathology the paper selects three prototype applications: telepathology in teleeducation, expert advice for preselected details of a slide and finally telepathology for remote diagnosis. The most challenging field for remote diagnosis is the application in the frozen section scenario. The paper starts with the mental experiment to map conventional procedures to counterparts in telepathology. Technical opportunities and economical restrictions of telepathology equipment are discussed with respect to the components: electronic camera, display devices, haptic sensors and displays, available telecommunication channels and telepathology software. As an example and for illustration of the state of the art for an advanced telemicroscopy system able to perform remote frozen section diagnosis, the HISTKOM equipment is presented in more details. The section concerning future developments regards the aspects of the acceptance by tentative users, legal aspects, costs and affordability of equipment, the market for equipment components and the adequate telecommunication services. Further is regarded the mutual influence of properties of existing systems and application experiences gained with them on the next generation of equipment and application software. Conclusions and references close the paper.

The outcome of Lyme borreliosis in children

Austria is an endemic area for Lyme borreliosis. The IgG seroprevalence of healthy blood donors as investigated by a DAKO flagellum-ELISA in Graz/Styria is 13%. In order to determine whether this high seroprevalence is caused by infection in childhood, 36 children aged 3 to 18 years (mean, 10.1 years) were followed up over 2 to 20 months (mean, 11.1 months) and reinvestigated for clinical symptoms and antibodies against B. burgdorferi by a commercial flagellum ELISA and a commercial B. garinii Western blot (WB). Twenty-seven children had erythema migrans (EM), one of them with reinfection, 5 had borrelia lymphocytoma (BL), 2 EM and BL, 1 acrodermatitis chronica atrophicans and 1 ACA/circumscribed scleroderma. Before treatment with either phenoxymethylpenicillin, amoxicillin, or minocyclin for 3-4 weeks, 64% of the patients were IgM and 44%, IgG seropositive. Clinically, all but 5 patients with EM recovered from Lyme borreliosis. Among these 5 patients--one of them with reinfection of EM--3 had mild arthralgia, 1 recurrent headache and 1 concentration disturbance. Only 2 children with arthralgia were IgM positive by ELISA and WB. One of 5 BL patients had a persistent swelling of the ear lobe although with a negative serology before and after several antibiotic treatments and at follow up. In 16 children serological investigations were performed after more than 12 months (range, 13-20 months). Eighteen percent of them had IgM antibodies by ELISA, 25% by WB, and 6% IgG antibodies by ELISA and 6% by WB. Although there was a decline of antibody response from 64% to 18% for IgM and from 44% to 6% for IgG as measured by ELISA, children remain seropositive for more than 1 year with or without clinical symptoms. The relevance of the association with clinical symptoms can be raised by combining several diagnostic methods. It is assumed that recurrent, often silent, infections might increase antibody titres. It should be noted that antibody titres also generally increase with the age of individuals.

Fibrinolytic proteins in apoptotic human umbilical vein endothelial cells

Endothelial cells express fibrinolytic proteins including: urokinase (u-PA) and tissue type (t-PA) plasminogen activators, type-1 (PAI-1) and 2 (PAI-2) plasminogen activator inhibitors, and u-PA receptor (u-PAR). Apoptotic endothelial cells detach, potentially forming both local and circulating microthrombi in vivo. In this article, apoptotic human umbilical vein endothelium was obtained by serum starvation and compared with nonapoptotic cells rescued from death with fresh medium containing serum. Antigen levels for t-PA, PAI-1, PAI-2, and u-PAR were reduced greatly in apoptosis (p< 0.05). In contrast, u-PA levels were similar in apoptotic as compared with rescued cells (p<0.05). Radioactive amino acids were used to determine absolute levels of protein synthesis and degradation in these cells. Reduced antigen levels likely were due to proteolysis as there was 98% total protein degradation and very little protein synthesis in apoptotic endothelial cells. Also, u-PA levels in apoptotic endothelial cells were not affected by the protein synthesis inhibitor cycloheximide. Endothelial cells in inflammatory sites are exposed to cytokines, which increase both apoptosis and u-PA levels. Data from this article support the idea that maintained u-PA levels in apoptotic endothelium may protect from micro-thrombosis in inflammatory sites as well as in the circulation.

Field test to evaluate telepathology in telemedicine

Telepathology is currently performed only on prototype systems. The application of telepathology consultations differs from the conventional procedure because of the technical and cost restrictions. This paper outlines technical concepts and the principal hardware and software modules necessary for telemicroscopy equipment. A field test to gather information concerning the user needs and to evaluate parameters of telepathology consultation sessions is reported.

Circadian gating of cell division in cyanobacteria growing with average doubling times of less than 24 hours

To ascertain whether the circadian oscillator in the prokaryotic cyanobacterium Synechococcus PCC 7942 regulates the timing of cell division in rapidly growing cultures, we measured the rate of cell division, DNA content, cell size, and gene expression (monitored by luminescence of the PpsbAI::luxAB reporter) in cultures that were continuously diluted to maintain an approximately equal cell density. We found that populations dividing at rates as rapid as once per 10 h manifest circadian gating of cell division, since phases in which cell division slows or stops recur with a circadian periodicity. The data clearly show that Synechococcus cells growing with doubling times that are considerably faster than once per 24 h nonetheless express robust circadian rhythms of cell division and gene expression. Apparently Synechococcus cells are able to simultaneously sustain two timing circuits that express significantly different periods.

A hospital as victim and responder: the Sepulveda VA Medical Center and the Northridge earthquake

Many hospital emergency plans focus on the hospital as a disaster responder, with a fully operational medical facility, able to receive and treat mass casualties from a clearly defined accident scene. However, hospitals need to prepare a response for extreme casualty events such as earthquakes, tornadoes, or hurricanes. This article describes the planning, mitigation, response, and recovery of a major medical--surgical center thrust into a victim responder role following the devastating Northridge earthquake. The subsequent evacuation and care of patients, treatment of casualties, incident command, prior education and training, and recovery issues are addressed.

Congenital sideroblastic anemia successfully treated by allogeneic bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) was carried out on a 34-month-old boy with congenital sideroblastic anemia. The patient had been red blood cell transfusion dependent since the age of 7 weeks. He did not respond to therapy with pyridoxine and developed secondary progressive hemosiderosis. The preparatory regimen consisted of busulfan (3.5 mg/kg for 4 days) and cyclophosphamide (50 mg/kg for 4 days). Full engraftment of donor bone marrow was achieved and effective hemopoiesis is still maintained 3 years after BMT.

[Oligosymptomatic Bourneville-Pringle tuberous sclerosis of the brain with giant cell astrocytoma]

We report on a 9-year-old boy who developed subependymal giant-cell astrocytoma associated with tuberous sclerosis. Apart from a few hypopigmented skin patches, the boy's clinical picture was completely unremarkable until the onset of diplopia and vertigo reflecting increased intracranial pressure. Magnetic resonance imaging of the brain revealed subcortical hamartomas in addition to the intraventricular tumour. Seizures and mental retardation were absent. The boy's mother had suffered from seizures during childhood and presented with typical skin lesions. The importance of thorough examination and regular follow-up even in patients with oligosymptomatic variants of tuberous sclerosis is emphasized.

Sulfide induction of synthesis of a periplasmic protein in the cyanobacterium Oscillatoria limnetica

Two proteins which may play a role in the induction of anoxygenic photosynthesis in Oscillatoria limnetica have been demonstrated by comparing the pattern of labeling during pulses of [35S]methionine of cells incubated under inducing conditions [anaerobic conditions plus 3-(3,4-dichlorophenyl)-1,1-dimethylurea, light, and sulfide) with that of cells incubated under noninducing conditions (without sulfide). The major inducible protein has an apparent molecular mass of 11.5 kilodaltons and is associated with a less strongly labeled 12.5-kilodalton protein. The synthesis of both proteins commences within the first 30 min of induction and continues throughout the 2-h induction period. Since these proteins are not synthesized in the presence of dithionite without sulfide, low redox potential alone is insufficient as an inducer of these proteins. Lysozyme treatment and/or osmotic shock of intact cells results in the release of the sulfide-induced proteins. Our data thus indicate that these proteins are located in the periplasmic space of the cells.

Sulfide-dependent photosynthetic electron flow coupled to proton translocation in thylakoids of the cyanobacterium Oscillatoria limnetica

Light-induced proton translocation coupled to sulfide-dependent electron transport has been studied in isolated thylakoids of the cyanobacterium Oscillatoria limnetica. The thylakoids are obtained by osmotic shock of washed spheroplasts, prepared with glycine-betaine as the osmotic stabilizer. 13C NMR studies suggests that betaine is the major osmoregulator in O. limnetica. Thylakoid preparations obtained from both sulfide-induced anoxygenic cells and noninduced oxygenic cells are capable of proton pumping coupled to phenazinemethosulfate-mediated cyclic electron flow. However, only in the induced thylakoids can sulfide-dependent proton gradient (delta pH) formation be measured, using either NADP or methyl viologen as the terminal acceptor. Sulfide-dependent delta pH formation correlates with a high-affinity electron donation site (apparent Km 44 microM at pH 7.9). This site is not lost upon washing of the thylakoids. In addition, both sulfide-dependent electron transport and delta pH formation are sensitive to inhibitors of the cytochrome b6f complex such as 2-n-nonyl-4-hydroxyquinoline-N-oxide, 2,4-dinitrophenyl ether of 2-iodo-4-nitrothymol, or stigmatellin. Sulfide-dependent NADP photoreduction of low affinity (which does not saturate by as much as 7 mM sulfide) is detected in both induced and noninduced thylakoids, but this activity is insensitive to the inhibitors and is not coupled to proton transport. It is suggested that the adaptation of O. limnetica to anoxygenic photosynthesis involves the induction of a thylakoid factor(s) which creates a high-affinity site for sulfide, and the transfer of its electrons via the cytochrome b6f complex, coupled to proton translocation.

Ontogeny of adenosine 3',5'-monophosphate metabolism in rabbit cerebral cortex. Development of responses to histamine, norepinephrine, adenosine, and glutamate

The effects of norepinephrine (NE), histamine (HIST), glutamate, and adenosine, singly and in combinations, on the accumulation of adenosine 3',5'-monophosphate (cyclic AMP) in slices of rabbit cerebral cortex were examined using tissue from animals 4 days before to 38 days after birth. A response to NE became visible 2 days before birth and increased to a maximum at 7 days after birth before declining toward the small adult value during the second post-natal week. During this period NE was at least twice as efficacious as isoproterenol, and both alpha- and beta-adrenergic antagonists had prominent inhibitory effects. Responses to HIST were already apparent 4 days before birth and increased in an irregular fashion thereafter, sometimes exceeding the adult value during the second post-natal week. The response to adenosine was not visible until birth and gradually increased toward the adult value during the entire period examined. Synergistic responses to various combinations of the three agents were first detected at 2 to 4 days before birth. The degree of synergism was larger during the neonatal period than that found in adult tissue; no synergism between HIST and adenosine persisted in the adult. During the first post-natal week, L-glutamate produced very large increases of cyclic AMP accumulation in the presence of either adenosine or histamine plus theophylline; smaller but substantial responses occurred in combination with NE. Responses to glutamate declined progressively after about the tenth post-natal day.

[Comparison of the efficacy of parenteral and enteral pertussis immunization in the rabbit (author's transl)]

The effects of immunization with inactivated B. pertussis were studied in the rabbit using enteral (oral and via suppositories) and parenteral immunization routes. The rise in agglutinating and complement-binding immunoglobulins in the rabbit serum was about equal following immunization by suppository and parenteral administration, but the demonstration of local immunity (immunoglobulins reacting with B. pertussis in salive) by immunofluorescence methods was observed only in the group immunized with enterally-administered B. pertussis.

[Zinc uptake of normal and leukaemic lymphocytes in an in vitro model (author's transl)]

Zinc uptake and/or possible exchange by isolated lymphocytes from normal persons and from patients with chronic lymphatic leukemia and chronic myeloid leukemia were studied in an in vitro model. The uptake of zinc per 10(9) lymphocytes of normal persons was 60 +/- 10 nanomoles and 120 +/- 15 nanomoles during incubation for 30 and 60 minutes, respectively. Two out of the 3 patients with chronic myeloid leukemia showed normal zinc uptake in this test system, whereas zinc uptake by lymphocytes from patients with chronic lymphatic leukemia was significantly decreased (22+/-8 nanomoles in 30 minutes and 35+/-10 nanomoles in 60 minutes).