Fatal fat embolism after vertebroplasty: identification of the high-risk patient.

We report a rare complication of autopsy-proven fat and bone marrow embolization following percutaneous vertebroplasty in a patient who had no evidence of cement leakage. Cement injection was done during one patient encounter, covering 3 vertebral levels by using a unipedicular approach. Patients may have complications even without polymethylmethacrylate leakage.

Detection of HIV-1 DNA in needle/syringes, paraphernalia, and washes from shooting galleries in Miami: a preliminary laboratory report.

Shared use of injection equipment (needle/syringes), registering, booting, and backloading are practices among injection drug users (IDUs) that increase the risk for transmission of human immunodeficiency virus type 1 (HIV-1). The sharing of injection paraphernalia (including cookers and cottons) and washwater for rinsing used needle/syringes and dissolving drugs could be potential sources for secondary transmission of HIV-1. Laboratory rinses were made from needle/syringes, cottons, and cookers obtained from shooting galleries, and washwaters were obtained from shooting galleries in Miami. Three rinses were analyzed and antibodies to HIV-1 proteins were detected by using Western blot and HIV-1 DNA was detected by using nested polymerase chain reaction (PCR) specific for the gag and envelope genes of HIV-1. Antibodies to HIV-1 proteins were detected in 12 (52%) of 23 rinses from visibly contaminated needle/syringes, in three (18%) of 17 rinses from cottons, in three (14%) of 21 rinses from cookers, and in one (6%) of 17 washwaters. No antibodies were detected in laboratory rinses from visibly clean needles. Using nested PCR followed by Southern blot confirmation of the amplified targets, HIV-1 gag gene DNA was detected in 16 (84%) of 19 and envelope gene DNA in 17 (85%) of 20 laboratory rinses from visibly contaminated needle/syringes. We detected gag and envelope gene DNA, respectively, in three (27%) and four (36%) of 11 cottons, in six (46%) and seven (54%) of 13 cookers, and in five (38%) of 13 and in 10 (67%) of 15 washwaters from shooting galleries. No HIV-1 DNA was detected in laboratory rinses from visibly clean needles. These results indicate that HIV-1 might be present in contaminated cottons, cookers, and washwaters as well as in contaminated needle/syringes at shooting galleries. Reduction of risks of exposure to HIV-1 among IDUs may require modification of behaviors that are ancillary to the act of injection, such as the use of common cookers, cottons, and washwater.

HIV-1 heterogeneity and cytokines. Neuropathogenesis.

Mild manifestations (HIV-1 associated minor cognitive/motor disorder), severe manifestations (HIV-1 associated dementia complex and HIV-1 associated myelopathy), and sensory neuropathy are consequences of HIV-1 infection. Our goal is to elucidate the role of HIV-1 in the complications of AIDS including cytokine immunopathology and HIV-1 DNA sequence variants. We have examined the brain and sensory ganglia from 60 AIDS patients and 20 seronegative controls using PCR, DNA sequencing of the HIV-1 envelope protein (env), in situ hybridization (ISH), and immunohistochemistry (IHC). Using our combined ISH-IHC technique, we could identify different types of cells and HIV-1 simultaneously in cryostat and paraffin sections. We found HIV-1 predominantly in macrophage/microglia in brain. In dorsal root ganglia (DRG) we found rare macrophages infected with HIV-1 and neurons and interstitial cells (including macrophages) which were apoptotic. Cytokines were detected in mononuclear and endothelial cells near neurons. We achieved single copy sensitivity detecting HIV-1 in nervous tissue using nested PCR. We sequenced HIV-1, DNA from 3 intravenous drug users (IDUs): from brain, CSF, and blood. PCR amplification was followed by cloning and then sequencing the HIV-1 insert: V1-V5 regions of the envelope (env) gene. We found that the env genes had increased sequence variation compared to the literature, cDNA sequences derived from RNA were less heterogeneous than clones derived from DNA from the same specimens, clones derived from brain are more closely related (show restricted heterogeneity) compared to clones from blood and CSF from the same patients. Patient 149 clones we examined to date did not correspond to any of the designated subtypes (A-F) of HIV-1 based on the DNA sequences of the C2-V3 regions. Finally, the HIV-1 RNA produced in these tissues is derived from a minority of DNA clones. Although HIV-1 infected macrophages are not entirely responsible for pathology in the brain and less so in sensory ganglia, some of the products of infection, cytokines, are more widespread in these tissues. Furthermore, HIV-1 strains infecting the brain appear to exhibit restricted heterogeneity compared to autologous CSF and blood and these strains may be associated with cytokines and pathology. HIV-1 strains that infect nervous tissue and cytokines produced in this tissue may effect neuropathogenesis, in vivo, in spite of low levels of local HIV-1 infection. We attempt to delineate, here, common sequence variations in HIV-1 isolates in the hope of developing future therapeutic strategies.

Role of immune activation and cytokine expression in HIV-1-associated neurologic diseases.

Central nervous system (CNS) involvement is common during human immunodeficiency virus type-1 (HIV-1) infection. The neurologic disease of the CNS most frequently observed during acquired immunodeficiency syndrome (AIDS) is HIV-1-associated cognitive/motor complex or AIDS dementia complex (ADC), which is most likely a direct consequence of HIV-1 infection of the CNS. The peripheral nervous system (PNS) is also affected in HIV-1-infected individuals and there are several features of immune- and cytokine-related pathogenesis in both the CNS and PNS that are reviewed. Several lines of evidence demonstrate aspects of immune activation in the CNS and peripheral nervous system (PNS) of HIV-1-infected individuals. The relative paucity of HIV-1 expression in contrast to widespread functional and pathologic changes in the CNS and PNS of AIDS patients, and the lack of evidence of productive infection of HIV-1 in neuronal cells in vivo lead to the possibility of indirect or immunopathogenic mechanisms for HIV-1-related neurologic diseases. Proposed mechanisms of neuronal and glial cell damage are injury of oligodendrocytes by tumor necrosis factor-alpha (TNF-alpha) released from activated macrophage/microglia, calcium-dependent excitoneurotoxicity induced by gp120 HIV-1 envelope protein, N-methyl-D-aspartate (NMDA) receptor-mediated neurotoxicity by quinolinic acid (a product of activated macrophages), cell injury by HIV-1-specific cytotoxic T cells, and apoptosis of oligodendrocytes or neurons triggered by interaction between cell surface receptors and HIV-1 gp120 protein. Common to those mechanisms is the dependence on cellular activation with expression of proinflammatory cytokines (TNF-alpha, interleukin-1). Amplification of activation signals through the cytokine network by macrophage/astrocyte/endothelial cell interactions, and cell-to-cell contact between activated macrophages and neural cells by upregulation of adhesion molecules dramatically enhances the toxic effect of macrophage products. Expression of immunosuppressive cytokines such as interleukin-4, interleukin-6, and transforming growth factor-beta is also increased in the CNS and PNS of HIV-1-infected patients. This may serve as neuroprotective and regenerative mechanism against insults to nervous system tissue.

Expression of HIV-1 and interleukin-6 in lumbosacral dorsal root ganglia of patients with AIDS.

We examined the immunopathology and the expression of human immunodeficiency virus type 1 (HIV-1) in lumbosacral dorsal root ganglia (DRGs) from 16 patients with acquired immunodeficiency syndrome (AIDS) and 10 HIV-1-seronegative controls. Using in situ hybridization, we detected HIV-1 RNA in a few perivascular cells in DRGs from five of 16 AIDS patients (31%). In addition, using polymerase chain reaction, we detected HIV-1 DNA more frequently in DRGs from four of five AIDS patients (80%) examined. We detected interleukin-6 (IL-6) immunoreactivity in endothelial cells in DRGs from seven of 16 AIDS patients (44%) but from none of 10 HIV-1-seronegative controls (0%). We found more nodules of Nageotte, CD8+ T lymphocytes, and intercellular adhesion molecule-1 (ICAM-1)-positive endothelial cells and mononuclear cells in DRGs from AIDS patients than in DRGs from controls. Increased numbers of nodules of Nageotte in DRGs of AIDS patients were associated with detection of HIV-1 RNA by in situ hybridization and detection of IL-6 by immunohistochemistry. We conclude that low levels of replication of HIV-1, through cytotoxic T lymphocytes or expression of cytokines, may play a role in the subclinical degeneration of sensory neurons frequently observed in DRGs of AIDS patients.

Infection of human neural cell aggregate cultures with a clinical isolate of cytomegalovirus.

Human neural cell aggregate cultures were prepared from dissociated fetal brain tissue and maintained in rotation culture. After 35 days in culture, aggregates had the histologic appearance of dense, immature, neural cells in a tightly packed neuropil. Electron microscopy revealed ultrastructural features suggestive of immature neurons and neuroglia. In addition, neuron-specific enolase and glial fibrillary acidic protein associated with radial glial cells were detected within the aggregates by immunoperoxidase staining. When infected with a laboratory-adapted strain of cytomegalovirus (CMV), [AD169], cells containing large, bizarre, nuclei and CMV-induced intranuclear inclusion bodies were dispersed throughout the aggregates at 16 days postinfection. In situ hybridization using a CMV-specific DNA probe and electron microscopy confirmed the presence of virus sequences as well as virus particles at histologic sites of cytopathology. In sharp contrast, aggregate cultures infected with a CMV strain recovered from the retina of an acquired immune deficiency syndrome (AIDS) patient with CMV retinitis and encephalitis displayed distinct foci of cytopathology at 23 days postinfection, a pattern not observed in CMV [AD169]-infected aggregates. Our findings suggest that human neural cell aggregates represent a a promising multicellular non-neoplastic culture system in which to study the replication of human neurotropic viruses within neural tissue.

Retraining of functional gait through the reduction of upper extremity weight-bearing in chronic cerebellar ataxia.

Patients with chronic ataxia resulting from traumatic central nervous system (CNS) damage frequently attain a gait pattern dependent upon upper extremity weight-bearing (UEWB). Traditional attempts to train these patients may perpetuate UEWB dependency, by not allowing optimal facilitation of balance and associated movement control required for independent ambulation. In the present study an ambulation retraining approach designed to facilitate coordination and balance while minimizing UEWB was used. This approach can allow the patient to train outside of the clinic; only about 5% of the actual therapy hours involved a therapist.

Postmortem diagnosis of myocardial disease by enzyme analysis of pericardial fluid.

The authors measured the activities of CK, LDH, and their isoenzymes in pericardial fluid to determine their usefulness in evaluating acute myocardial injury. Their prospective study reveals that these enzymes significantly are elevated in cardiac deaths in contrast to fatalities from noncardiac causes. Also, a group of healthy individuals who were victims of violent deaths and died from extracardiac injuries had enzyme elevations greater than those found in acute cardiac deaths, suggesting catecholamine-mediated myocardial injury (stress cardiomyopathy) as part of the physiologic response to trauma. Measurements of cardiac enzymes in pericardial fluid may prove useful in establishing the postmortem diagnosis of acute myocardial injury in instances when such injury is suspected but cannot be established by ordinary histologic methods. Studies such as this may help in defining the participation of myocardial injury as one of the lethal mechanisms in various causes of death.

The significance of giant mitochondria in liver biopsies as observed by light microscopy.

One hundred forty-three liver biopsy specimens were evaluated by light microscopy for giant mitochondria (GM), and were correlated with a variety of histological and clinical parameters. GM were found in 57% of the biopsy specimens. In alcoholic liver diseases, GM are mostly round in shape, are centrilobular in distribution, and frequently coexist with Mallory bodies. The frequency of hepatocytes containing GM in alcoholic liver disease is the highest of all groups. In nonalcoholic liver diseases, GM are round or needle-shaped, distributed randomly or in the periphery of the hepatic lobules, and the frequency of hepatocytes containing GM is less than that in alcoholic liver disease. These features are useful in separating alcoholic from nonalcoholic liver diseases. While GM appear to represent early hepatocellular injury, certain factors appear to influence GM formation in nonalcoholic liver diseases, including high alcohol consumption in both alcoholic and nonalcoholic liver diseases, fatty change, under-nutrition or abnormal nutrition, and upper gastrointestinal tract disorders.