Merger offers IS managers flexibility & less stressful integrating, downsizing, & outsourcing. Interview by Bill Childs

A merger between two multi-million dollar IS firms in July 1993 created a company with $315 million in sales and a sharp focus on healthcare. National Healthtech Corp., parent firm of MRI, brought the focus to the deal. And Dallas-based Affiliated Computer Services, a data services provider to financial, commercial and healthcare organizations, brought telecommunications and outsourcing expertise. Bill Childs, editor-in-chief, recently spoke with the two firms' principals--Richard A. Montgomery, CEO of National Healthtech Corp., and Steve Carpenter, senior VP of ACS and COO of NHC. Excerpts from their conversation follow.

A persistent hindlimb ischemia model in the rabbit

The study of new approaches for the treatment of limb-threatening ischemia has been hampered by the lack of a suitable animal model of persistent limb ischemia. We describe the development and evaluation of an animal model of persistent hindlimb ischemia, in which ischemia was induced in the left hindlimb of 28 rabbits by ligation of the distal external iliac artery and excision of the common and superficial femoral arteries. The severity of the ischemia and its relief in each animal were evaluated every 10 days postoperatively until day 40 (all animals) or day 90 (five animals). Nine animals developed superficial tissue necrosis in the foot, but no deaths were attributable to the ischemia-inducing procedure. Angiography demonstrated minimal collateralization and sluggish filling of distal vessels up to postoperative day 90. This was accompanied by a decrease at rest in the calf blood flow ratio (p < 0.005 vs day 0), an increase in lactic acid in the femoral venous blood (left vs right side, p < 0.002) up to postoperative day 40, and a decrease in the calf blood pressure ratio (p < 0.0001 vs day 0) up to day 90. Histologic study of the gastrocnemius muscle demonstrated evidence of atrophy and fibrosis in the left hindlimb. This model can be used to evaluate direct and indirect approaches to the treatment of chronic limb ischemia.

Identification of the activation domain of equine infectious anemia virus rev

Several members of the lentivirus family of complex retroviruses have been shown to encode proteins that are functionally equivalent to the Rev posttranscriptional regulatory protein of human immunodeficiency virus type 1 (HIV-1). Furthermore, the domain organization of HIV-1 Rev, featuring a highly basic N-terminal RNA binding domain and a leucin-rich C-terminal effector domain, has also been shown to be highly conserved among Rev proteins derived from not only the primate but also the ovine and caprine lentiviruses. Although it has therefore appeared highly probable that the lentivirus equine infectious anemia virus (EIAV) also encodes a Rev, the predicted amino acid sequence of this putative EIAV regulatory protein does not display any evident homology to the basic and leucine-rich motifs characteristic of other known Rev proteins. By fusion of different segments of the proposed EIAV Rev protein to the well-defined RNA binding domain of either HIV-1 or visna virus Rev, we have identified a segment of this EIAV protein that can efficiently substitute in cis for the otherwise essential activation motif. Interestingly, the minimal EIAV Rev activation motif identified in this study comprises approximately 18 amino acids located toward the protein N terminus that lack any evident similarity to the leucine-rich activation domains found in these other lentivirus Rev proteins. It therefore appears that the Rev protein of EIAV, while analogous in function to Rev proteins defined in lentiviruses of primate, ovine, and caprine origin, is nevertheless distinguished by an entirely novel domain organization.

Pathology of the inflammatory myopathies

Careful examination of muscle biopsy specimens is indispensable in the diagnostic work-up of patients whose clinical picture is suggestive of or consistent with an inflammatory myopathy. Pathological diagnosis can, in the vast majority of cases, determine the specific type of inflammatory myopathy which is of paramount importance for prognosis and therapy. The pathological study of muscle has also been useful to reveal information pertaining to the pathogenesis of the different entities and ultimately it may also lead us to the precise aetiology.

In vitro detection of bovine immunodeficiency-like virus using monoclonal antibodies generated to a recombinant gag fusion protein

An Escherichia coli recombinant fusion protein containing the major core protein of bovine immunodeficiency-like virus (BIV) was used to immunize mice for generation of monoclonal antibodies to BIV p26. Eight hybridomas specific for BIV p26 were identified and two antibodies, designated 104 and 142, were further characterized. Both 104 and 142 antibodies were isotyped as IgG1; they reacted specifically with both BIV p26 and the recombinant fusion protein in Western immunoblot analyses. However, the epitope specificity of the antibodies was different. Immunoperoxidase assays were used to determine if antibodies 104 and/or 142 could detect BIV replication in cell culture. Both antibodies were found to react with BIV-induced syncytia and individual BIV-infected cells. The antibodies were also used successfully in a focal immunoassay for quantitation of BIV-infected cells. These antibodies will provide valuable reagents for detection and quantitation of BIV replication in studies of viral pathogenesis and immunity.

Metachromatic leukodystrophy: multiple nonfunctional and pseudodeficiency alleles in a pedigree: problems with diagnosis and counseling

Metachromatic leukodystrophy is due to deficient activity of arylsulfatase A, an enzyme important in myelin catabolism. The deficiency can be caused by different point mutations in the gene coding for arylsulfatase A (nonfunctional alleles). In addition, certain mutations result in low levels of enzyme activity detectable with artificial substrates in vitro but no clinical dysfunction (pseudodeficiency alleles). The described family has various combinations of normal, nonfunctional, and pseudodeficiency alleles that presented diagnostic and counseling dilemmas which were resolved at the genomic level. We find no evidence that compound heterozygote individuals have subclinical involvement of the nervous system. We report the clinical, pathological, electrophysiological, imaging, biochemical, and genetic data of this family and discuss the difficulties in analyzing such pedigrees.

Kinetics of peptide hydrolysis and amino acid decomposition at high temperature

Dipeptide hydrolysis and amino acid decomposition appear to follow a first-order rate law. The hydrolysis rate increases exponentially with increasing temperature in aqueous solution at both 265 atm and water steam pressures over the temperature range of 100 to 220 degrees C. Dipeptide hydrolysis has a lower apparent activation energy at 265 atm (44.1 KJ/mol) than at water steam pressure (98.9 KJ/mol). At lower temperatures (<200-220 degrees C), the rate of peptide bond hydrolysis is faster at 265 atm than at water steam pressure. At higher temperatures (>200-220 degrees C), however, peptide bond hydrolysis is slower at 265 atm than at water steam pressure. In aqueous solution, amino acid decomposition rates also increase exponentially with increasing temperature. Amino acid decomposition rates are much higher at 265 atm than at water steam pressure over the entire temperature range investigated.

Identification of transactivation-response sequences in the long terminal repeat of bovine immunodeficiency-like virus

Transient expression assays using the reporter gene that encodes chloramphenicol acetyltransferase were used to identify cis-acting sequences necessary for bovine immunodeficiency-like virus (BIV) transactivation. Computer analyses identified two RNA stem-loop structures located immediately downstream of the transcription start site in the long terminal repeat. Deletion analysis of the long terminal repeat indicated that sequences containing the proximal stem-loop structure located between +4 and +31 are required for virus-specific transactivation. Therefore, BIV likely utilizes a mechanism of transactivation similar to that of the human and simian lentiviruses.

Cerebral vein thrombosis due to hereditary antithrombin III deficiency

Cerebral vein thrombosis, also called superior sagittal sinus thrombosis, is a well recognized clinical and radiologic entity associated with a variety of medical disorders. We report a patient with fatal cerebral vein thrombosis following myelography, in whom the cause was familial antithrombin III (AT3) deficiency. Unsuspected AT3 deficiency should be considered in cases of unexplained cerebral venous thromboses.

Effect of bovine immunodeficiency-like virus infection on immune function in experimentally infected cattle

Bovine immunodeficiency-like virus (BIV) is a bovine lentivirus that has antigenic and genetic homology with the human immunodeficiency virus. Little work has been reported on the effect of BIV infection on bovine immune function. This study was designed to evaluate lymphocyte blastogenesis, mononuclear cell subset numbers, neutrophil function, hematology, and clinical signs in three groups of cattle. These groups were evaluated at 0-2 months post inoculation (PI, Group 1), 4-5 months PI (Group 2), or 19-27 months PI (Group 3). BIV infected animals were inoculated with the R-29 isolate of BIV in tissue culture cells, peripheral blood mononuclear cells from a R-29 infected calf, or a molecular clone of the R-29 isolate. Most inoculated animals seroconverted to BIV by Western immunoblot. BIV was reisolated from most of the animals inoculated. BIV infection was associated with an increase in the lymphocyte blastogenic response to the mitogen phytohemagglutinin in Groups 2 and 3. Neutrophil antibody dependent cell mediated cytotoxicity and neutrophil iodination were decreased (P < 0.05) in BIV infected cattle (Groups 2 and 3 and Group 3, respectively). All animals were clinically normal during the evaluation periods. Notable differences were not observed in the other assessments performed. Work with additional BIV isolates and over longer time frames is warranted.

Localization and quantitation of the chromosome 6-encoded dystrophin-related protein in normal and pathological human muscle

A dystrophin-related protein (DRP) encoded by a gene on chromosome 6 was studied in 14 normal and 79 pathological human skeletal muscle biopsies, as well as in cultured myotubes by light microscopic immunocytochemistry and quantitative immunoblots. In normal muscle immunoreactive DRP was present at the postjunctional surface membrane, at the surface of satellite cells, in the walls of blood vessels, in Schwann cells and in perineurium of intramuscular nerves. All of this produced a weak signal on immunoblots. In Duchenne/Becker dystrophy (DMD/BMD) and in polymyositis (PM) or dermatomyositis (DM) DRP was present throughout the extrajunctional surface membrane of extra- and intrafusal muscle fibers, particularly regenerating ones. This produced a 15-17-fold increase of DRP over normal in DMD/BMD and 4-10-fold increase over normal in PM and DM on immunoblots. In other pathological muscles, DRP localization pattern and quantity was about the same as in normals. Dystrophin-related protein was present in about the same amounts and distribution in normal and DMD cultured myoblasts and myotubes. The molecular stimulus for the marked upregulation of DRP in DMD/BMD and in the inflammatory myopathies is not known. In DMD/BMD the diffuse sarcolemmal DRP may partially compensate for dystrophin deficiency.

Radiobiology of alpha particles. IV. Cell inactivation by alpha particles of energies 0.4-3.5 MeV

In this report the effectiveness of low-energy alpha particles in the range 0.4 to 3.5 MeV for cell killing is investigated. Four cell lines of different nuclear dimensions (AG1522, C3H 10T1/2, CHO-10B, and HS-23) are studied. Monte Carlo simulations are carried out to interpret the experimental results. They are presented as a function of dose to the nucleus, the total track length of alpha particles in the nucleus, and other parameters. It is found that the effectiveness of alpha particles for cell killing decreases with decreasing alpha-particle energy. The maximum RBE value is found to extend to LET values as high as 180 keV/microns. Although the LET might be the same, the effectiveness of alpha particles for cell killing is higher in the ascending part of the Bragg curve compared to descending part of the Bragg curve. The terminal tracks of alpha particles are observed to be less effective for cell killing.

Identification of alternatively spliced mRNAs encoding potential new regulatory proteins in cattle infected with bovine leukemia virus

The polymerase chain reaction was used to detect and characterize low-abundance bovine leukemia virus (BLV) mRNAs. In infected cattle we could detect spliced mRNA with a splice pattern consistent with a Tax/Rex mRNA, as well as at least four alternatively spliced RNAs. Two of the alternatively spliced mRNAs encoded hitherto unrecognized BLV proteins, designated RIII and GIV. The Tax/Rex and alternatively spliced mRNAs could be detected at their highest levels in BLV-infected cell cultures; the next highest levels were found in samples from calves experimentally infected at 6 weeks postinoculation. Alternatively spliced mRNAs were also expressed, albeit at lower levels, in naturally infected animals; they were detected by a nested polymerase chain reaction. Interestingly, the GIV mRNA was specifically detected in naturally infected cows with persistent lymphocytosis and in two of five calves at 6 months after experimental infection with BLV. Furthermore, the calf with the strongest signal for GIV had the highest lymphocyte counts. These data may suggest a correlation between expression of the GIV product and development of persistent lymphocytosis. Some of the donor and acceptor sites in the alternatively spliced mRNAs were highly unusual. The biological mechanisms and significance of such a choice of unexpected splice sites are currently unknown.

Glycogen branching enzyme deficiency in adult polyglucosan body disease

Branching enzyme activity was assayed in muscle, peripheral nerve, and leukocytes from 2 Ashkenazi-Jewish patients with adult polyglucosan body disease and 1 African-American and 3 Caucasian patients with the same clinical and pathological features. Branching enzyme activity was normal in the muscle specimens from both Jewish and non-Jewish patients. However, the activity was markedly decreased not only in the leukocytes from the 2 Jewish patients (confirming previous findings), but also in peripheral nerve specimens, whereas it was normal in nerve tissue and leukocytes from all non-Jewish patients. These data confirm a branching enzyme deficiency in a subgroup of patients with adult polyglucosan body disease, and show that the defect is tissue-specific, suggesting that adult polyglucosan body disease has more than one biochemical basis.

Loss and renewal of thick myofilaments in glucocorticoid-treated rat soleus after denervation and reinnervation

Denervation of rat soleus muscle and simultaneous administration of high doses of corticosteroids for 7 days caused marked muscle fiber atrophy and selective loss of thick myofilaments from many muscle fibers by light and electron microscopy. Myosin heavy chain/actin ratios were greatly reduced on polyacrylamide gel electrophoresis. Nerve crush instead of cut permitted reinnervation after 2 weeks and demonstrated the reversibility of the muscle changes within a week after reinnervation. There was formation of new thick filaments and their reintegration into myofibrils without further breakdown, although large areas of Z-disc streaming appeared. The mechanism of A-band breakdown remains obscure, but it presumably starts with limited proteolysis and continues with disaggregation of myosin molecules. This is consistent with our observation that the muscle fibers retain a relatively good reactivity to antibodies against myosin heavy chain 1 week after denervation and corticosteroid administration. A syndrome recalling these experiments is seen in severely asthmatic patients receiving corticosteroids and pharmacologically paralyzed for mechanical respiration.

Time course of cerebral blood flow and histological outcome after focal cerebral ischemia in rats

BACKGROUND AND PURPOSE

The relation between time-dependent changes in cerebral blood flow and the appearance of infarction after focal cerebral ischemia is still a matter for debate. The aim of this study was to measure perfusion after simultaneous occlusions of the left middle cerebral artery and ipsilateral common carotid artery in rats and correlate it with the timing and distribution of histological changes.

METHODS

We studied histological and cerebral blood flow changes 5 minutes and 4, 24, and 48 hours after the onset of focal ischemia. Blood flow was determined autoradiographically using [14C]iodoantipyrine. A coronal template subdivided into regions of interest was applied to the autoradiographs and the histological data.

RESULTS

In some regions of the nonoccluded hemisphere, cerebral blood flow 5 minutes after occlusion fell below 50% of normal. Many ischemic structures showed stable blood flow for 48 hours after occlusion, confirming that in this model reperfusion is minimal. Infarction occurred eventually in all areas in which blood flow at 5 minutes fell below 10% of that in control rats, but infarction appeared earlier in regions in which blood flow at 5 minutes was below 5% of that in control rats. When blood flow at 5 minutes rose above 12% of that in control rats, the occurrence of infarction became unpredictable.

CONCLUSIONS

Despite the general dependence of infarction on perfusion levels, blood flow was not a reliable indicator of those regions committed to infarction.

Staff anxieties about death in residential settings for elderly people

This study examined the relationship between death anxiety, the anxiety surrounding dealing practically with dying, and the level of experience of care assistants in residential settings for the elderly. It also examined the perception of the officer in charge of the establishment of the care assistants' level of anxiety. Age was the best predictor of both death anxiety and practical anxiety, the two being correlated. There was also a difference in perception of staff anxiety as a consequence of ethnic-group membership. The implications of this for training and practice are discussed.

Hydrocephalus and prominence of the choroid plexus: an unusual computed tomographic presentation of cerebral toxoplasmosis in AIDS

Toxoplasmosis is a frequent cause of infection of the central nervous system (CNS) in patients with acquired immunodeficiency syndrome. Computed tomography (CT) usually shows solitary or multiple parenchymal lesions, which are most often located in the cortex, the juxtacortical white matter and the basal ganglia. The authors describe a 30-year-old immunocompromised Haitian woman with pathologically proven CNS toxoplasmosis who presented with hydrocephalus and prominence of the choroid plexus; there was no evidence of focal parenchymal lesions in contrast-enhanced CT scans. An autopsy revealed diffuse destruction of the ependyma of the lateral, the third and the fourth ventricles. Necrosis was evident, and the periventricular tissues and the choroid plexus were infiltrated with neutrophils and macrophages. Pseudocysts of Toxoplasma were identified near the ventricular surface.

Characterization of early pathogenic effects after experimental infection of calves with bovine immunodeficiency-like virus

The early pathogenic effects of bovine immunodeficiency-like virus (BIV) were studied in calves experimentally inoculated with BIV. All animals inoculated with BIV R29-infected cells seroconverted by 6 weeks postinoculation, and BIV was recoverable from each animal at 2 weeks postinoculation. However, levels of BIV replication in vivo appeared to be low. In situ hybridization studies indicated that during peak periods of viral replication in vivo, less than 0.03% of peripheral blood mononuclear cells were expressing detectable levels of viral RNA. Moreover, the levels of viral RNA in these cells in vivo were less than 1/10 the levels observed in persistently infected cells in vitro. BIV-inoculated calves had significantly higher numbers of circulating lymphocytes, and follicular hyperplasia was observed in lymph nodes, hemal nodes, and spleen. The histopathological changes observed in BIV-infected calves were similar to changes found early after infection with the immunosuppressive lentiviruses, including human immunodeficiency virus type 1.

Vancomycin-associated linear IgA dermatosis. A report of three cases

BACKGROUND

Linear IgA dermatosis is an autoantibody-mediated, subepidermal blistering disease that is rarely associated with drug exposure.

OBJECTIVE

We report the development of linear IgA dermatosis in three patients associated with the administration of vancomycin and further characterize the immunopathology.

METHODS

Direct and indirect immunofluorescence assays were performed to characterize the immunoreactants, determine the subclass of the IgA deposits, and map the site of antibody deposition.

RESULTS

A subepidermal blistering disease developed in all patients shortly after vancomycin was initiated, which resolved on discontinuation of the drug. Immunofluorescence studies revealed linear deposits of IgA1 only at the basement membrane zone, below the lamina lucida. Circulating IgA anti-basement membrane zone antibodies were not detected.

CONCLUSION

Three patients had linear IgA dermatosis in association with the administration of vancomycin. All patients had linear deposits of IgA1 localized to the sublamina densa zone. Immunophenotypically, the disease in these patients mimics the pattern of IgA deposits seen in the majority of patients with idiopathic linear IgA dermatosis.

The pathological diagnosis of specific inflammatory myopathies

Pathological diagnosis of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM) should be possible in almost all cases when an appropriately involved muscle is biopsied. DM shows characteristic patterns of muscle fiber damage and capillary damage. Lymphocytes and macrophages are seen in PM and IBM partially invading non-necrotic fibers. IBM is also characterized by rimmed vacuoles with membranous whorls, characteristic masses of filaments in cytoplasm and sometimes in nuclei, and grouped atrophic fibers. Muscle fiber damage in PM is more variable. Inflammatory myopathy can be associated with HTLV-1 and HIV infection. In the latter a strong resemblance to PM is reported. Separate, still less well characterized forms of inflammatory myopathy occur in young children.

A chronic myopathy with coated vesicles and tubular masses

Two muscle biopsies from a 38-yr-old man with a lifelong mild chronic nonprogressive myopathy, showed accumulations of randomly oriented tubules of T-tubular origin, some of which had become greatly dilated and had accumulated osmiophilic material. The tubular masses lacked oxidative enzyme activity but during their evolution acquired esterase and acid phosphatase activity. Tubular areas appeared to break down and lead to intrusions of extracellular space into the center of fibers. Coated vesicles were numerous and often appeared to arise from the tubules. No abnormality could be detected on SDS PAGE electrophoresis of fractions from sucrose gradients.