Isolation of HTLV-III from cerebrospinal fluid and neural tissues of patients with neurologic syndromes related to the acquired immunodeficiency syndrome

Effects of HIV infection, perceived health and clinical status on a cohort at risk for AIDS

Data from a general population sample of 621 healthy homosexual men are used to evaluate the social and emotional effects of HIV antibody status, clinical signs detected by medical examination, and subjectively perceived symptoms. Participants are unaware of their serologic status at the time of data collection, thus allowing the effects of the virus to be separated from reactions to the knowledge of serologic status. The data show that seropositivity for HIV is not associated with elevated levels of social or emotional impairment. Clinical signs lead to impairment in baseline data, but these effects do not persist at a second wave. This weakening suggests that the effects are mediated by psychological pathways rather than biologic ones. This suspicion is confirmed in further analyses, which show that the effects of clinical signs are mediated by subjectively perceived symptoms. These results show that neither social nor emotional impairment is likely to be a prodromal sign of HIV infection in otherwise healthy homosexual men. The substantial levels of distress found among these men is more directly influenced by psychological determinants than biologic ones. This suggests that physicians should be aware of the psychological toll imposed on gay men who develop health problems in the current atmosphere of uncertainty regarding risk of AIDS.

Microglia in the giant cell encephalitis of acquired immune deficiency syndrome: proliferation, infection and fusion

The autopsied brains of three homosexual men with acquired immune deficiency syndrome (AIDS), progressive encephalopathy and widespread multinucleated giant cell encephalitis were investigated by lectin and immunohistochemical methods to ascertain the cellular distribution of a human immunodeficiency virus (HIV) core protein, p25. Abundant viral antigen was present in all brains, limited to perivascular macrophages, microglial and multinucleated cells, some bearing elongated cytoplasmic processes. The multinucleated cells were consistently labelled by the lectin Ricinus communis agglutinin-1, a marker for microglia, which demonstrated process-bearing variants of these cells. The prominent staining of microglia for viral antigen and the morphological suggestion that they fuse with other microglia and/or macrophages to form the multinucleated cells characteristic of HIV encephalitis indicate that microglia are probably direct targets of HIV infection and serve to propagate and amplify this retroviral encephalitis.

Intrathecal production of HIV antibodies in suspected AIDS encephalopathy

Thirty-one serum and CSF samples from 21 HIV-antibody-positive patients with neurological deficits were examined to prove or exclude intrathecal production of HIV antibodies. By dilution, sera were adjusted to the IgG concentration of the corresponding CSF samples. Both samples were then serially diluted in log2 steps down to the detection limit and were tested in an anti-HIV ELISA. From the dilution obtained at the cut-off level, a quotient QHIV was derived as an indicator of intrathecal production of HIV antibodies. Six of a total of eight samples with a QHIV value of greater than or equal to 2 were correlated which the clinical diagnosis of AIDS-related dementia complex (ARDC). However, a QHIV less than 1 did not exclude the development of ARDC, as was shown during follow-up in one case. Different methods are compared for the determination of intrathecal production of IgG and anti-HIV. A quotient QHIV greater than or equal to 2 is suggested to be highly indicative of intrathecal production of anti-HIV as well as of the development of ARDC.

Neurological complications of human immunodeficiency virus infection in patients with lymphadenopathy syndrome

To determine if there is a relationship between neurological abnormalities and human immunodeficiency virus (HIV) infection in patients with lymphadenopathy syndrome (LAS), we studied 39 homosexual/bisexual men with LAS (mean duration of LAS, 4.1 years) and 38 homosexual/bisexual men who were seronegative for HIV (controls). Six LAS patients had histories of symptoms suggesting mononeuropathy, 9 had symptoms suggesting distal symmetrical polyneuropathy, and 9 had histories of herpes zoster radiculitis. Overall, significantly more LAS patients (18) than controls (3) had histories of symptoms or signs of neurological abnormality (odds ratio, 10.0; p = 0.0003). By neuropsychological assessment, 9 of 18 LAS patients and 2 of 26 controls were abnormal (odds ratio, 12.0; p = 0.004). Of those abnormal on the neuropsychological assessment, the majority scored in the mildly impaired range. Magnetic resonance imaging was abnormal in 1 LAS patient and in 1 control. Neither neurological nor neuropsychological abnormalities correlated with duration of LAS, absolute T-helper lymphocyte count, or T-helper/T-suppressor lymphocyte ratio. These results indicate an association of neurological and neuropsychological abnormalities with HIV in patients with LAS. They suggest that mild neurological abnormalities in LAS are common and that HIV may directly or indirectly be the cause.

Pediatric AIDS. Neuroradiologic and neurodevelopmental findings

A group of 23 pediatric patients seropositive for HIV antibody were studied by computed tomography and evaluated neurodevelopmentally. Significant neurodevelopmental delays were found in over 95% of the patients studied. CT findings in six patients were normal and thirteen of 23 (57%) had prominence of the CSF spaces. Less frequent findings included calcifications in the basal ganglia and white matter. Cerebral mass lesions included one case of lymphoma and one case of hemorrhage. The CT findings in the pediatric age group differs from the adult population in that contrast enhancing inflammatory mass lesions are uncommon.

Myelopathy in AIDS. A clinical and electrophysiological study of 23 Danish patients

In a cross-sectional population study of Danish patients with AIDS 16 of 23 had clinical signs of neurological disease with muscle weakness or ataxia of the lower limbs as the dominant manifestation. Tibial and median nerve conduction was mildly slowed in a few patients and 15 had widening of cerebral ventricles at CT. However, all had prolonged latency of cortical evoked response following tibial nerve stimulation mainly due to slowing through the spinal cord. The prolongation of the latency of the evoked cortical responses was most pronounced in patients with lower limb ataxia and/or paresis. It is concluded that affection of the long tracts of the spinal cord are closely associated with the human immunodeficiency virus infection.

Antibody-mediated peripheral neuropathies associated with ARC and AIDS: successful treatment with plasmapheresis

Peripheral neuropathy is increasingly recognized in patients with AIDS as well as AIDS-related complex (ARC). Thirty homosexual men with polyneuropathy were evaluated in this study. Twenty-one had ARC and nine had AIDS. We observed three distinct clinical syndromes: distal sensorimotor polyneuropathy, chronic inflammatory demyelinating polyrediculoneuropathy (CIDP), and mononeuropathy multiplex. Circulating antibodies to peripheral nerve tissues were found in all patients. In six patients, treatment with plasma exchange was undertaken because of severe, progressive weakness. Four patients with clinical, electrophysiologic, and histologic evidence of CIDP improved with plasma exchange, three regaining normal function. These results suggest that the peripheral neuropathy associated with ARC and AIDS is immunologically mediated and that plasma exchange is an effective treatment in a subgroup of patients with this disorder.

Plasmapheresis in the treatment of acute relapsing inflammatory demyelinating polyradiculoneuropathy associated with human immunodeficiency virus infection: a case report

Neurologic complications, including both the acute and chronic forms of inflammatory demyelinating polyradiculoneuropathy (IDP) are becoming more prevalent among patients with the acquired immunodeficiency syndrome (AIDS) and AIDS-related-complex (ARC). Although the etiology of the above radiculoneuropathies is not known, an autoimmune process has been postulated. Plasmapheresis has been reported to be of benefit in both the acute and chronic forms of these neuropathies. In this report we describe the use of plasmapheresis in the treatment of a patient with ARC and the acute relapsing form of IDP. The treatment consisted of an intensive course of plasmapheresis following his initial presentation and after an acute relapse which occurred several weeks after his initial presentation. Both the initial presentation and relapse involved respiratory compromise necessitating intubation and mechanical ventilation. In both instances marked clinical improvement was achieved after initiation of plasmapheresis. Thus, plasmapheresis may have a role in the management of acute relapsing IDP associated with human immunodeficiency virus infection.

Review of central nervous system pathology in human immunodeficiency virus infection

Aseptic meningitis, subacute encephalitis, and vacuolar myelopathy are the three diseases of the central nervous system that are specifically related to or associated with human immunodeficiency virus (HIV) infection. HIV encephalitis initially is associated with myelin pallor and gliosis of the centrum semiovale, which is found in more than 90% of brains from patients dying with the acquired immunodeficiency syndrome. With increased severity of disease, multiple glial nodules with the multinucleated cells characteristic of HIV encephalitis are present throughout the cerebral white matter, basal ganglia, and cerebral cortex, and also may be found in cerebellum, brainstem, and spinal cord. HIV has been demonstrated in monocytes and multinucleated cells by electron microscopy, immunohistochemical techniques, and in situ hybridization. Vacuolar myelopathy occurs in approximately 30% of patients and is characterized by vacuolation of the white matter of the spinal cord that is most prominent in the posterior and lateral columns at thoracic levels. The severity of the pathological lesions correlates not only with symptoms and signs of spinal cord disease but also with dementia. Although the incidence of vacuolar myelopathy is increased in patients with HIV encephalitis, its etiology is not yet established.

Neuromuscular diseases associated with human immunodeficiency virus infection

The types of neuromuscular diseases associated with human immunodeficiency virus (HIV) infection are described. Our classification includes: (1) six subtypes of peripheral neuropathies--namely, acute Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, mononeuritis multiplex, an axonal, predominantly sensory, painful polyneuropathy, a sensory ataxic neuropathy due to ganglioneuronitis, and an inflammatory polyradiculoneuropathy presenting as cauda equina syndrome; (2) inflammatory myopathies (e.g., polymyositis); and (3) other less common neuromuscular manifestations, such as type II muscle fiber atrophy and nemaline myopathy. Although the exact incidence of clinical and subclinical neuromuscular diseases in HIV-positive and acquired immunodeficiency syndrome (AIDS) patients is unknown, estimates vary from 15 to almost 50% of such individuals. The type of neuropathy or myopathy related to the specific stage of HIV infection, the pathogenetic mechanisms involved, and effective therapies are discussed. A neuromuscular disease not only occurs in patients with AIDS and AIDS-related complex, but it can coincide with HIV seroconversion or it can be the only clinical indication of a chronic silent HIV infection. Chronic asymptomatic HIV infection should be considered in the differential diagnosis of certain acquired inflammatory polyneuropathies or myopathies. Precautions needed when doing electromyographic studies are discussed.

Neurological symptoms and neuropsychological abnormalities in lymphadenopathy syndrome

This case-control study of 39 homosexual or bisexual men who were human immunodeficiency virus (HIV)-seropositive and had lymphadenopathy syndrome and 38 HIV-seronegative homosexual or bisexual men indicates an association between neurological and neuropsychological abnormalities and HIV infection in patients with lymphadenopathy syndrome.

Nuclear bridges within multinucleated giant cells in subacute encephalitis of acquired immune deficiency syndrome (AIDS)

Six cases of subacute encephalitis in AIDS were examined with special reference to the nuclear morphology of multinucleated giant cells (MGC's). Although rare in some, all cases showed nuclear bridges which were thin strands connecting individual nuclei. Even more frequently observed were nuclear processes which were probably parts of nuclear bridges or disconnected ends of nuclear bridges. Nuclear bridges and processes were not features of mitosis but were composed of nucleoplasm. They appear to be a feature of MGC's in AIDS but may not be limited to this condition.

Molecular genetics and structure of the human immunodeficiency virus

A novel human lymphotropic virus capable of crippling the immune system by infecting and destroying T4 antigen-positive cells is now known to be the etiologic agent of the acquired immune deficiency syndrome (AIDS). The AIDS or human immunodeficiency virus (HIV) belongs to a family of RNA viruses called retroviruses. Several strains of HIV have been molecularly cloned, and DNA sequence comparisons have established that the proviral DNA genome is 9.7 kilobase pairs. The genome possesses characteristic retrovirus features including structural genes, flanked by long terminal repeats, in the order gag, pol, and env and, in addition, four unique nonstructural genes, several of which appear to be essential in regulating virus replication. Electron microscopy has played an important role in elucidating structural, genetic, and molecular properties of HIV and has aided in its classification as a member of the Lentivirnae retrovirus subfamily. Heteroduplex mapping methodologies pertinent to these findings are described. Although the relationships show considerable divergence, the similarities between HIV and lentiviruses are profound and encompass an indistinguishable morphology, genome sequence homology and topography, genomic diversity, and overlapping biology, including a preference for infecting cells of the immune system, a cytopathic effect in vitro, and the ability to produce a persistent, slowly progressing, degenerative disease in vivo. The newest HIV class (HIV-2) has recently been molecularly characterized. HIV-2 also bears all the hallmarks of a lentivirus but is more closely related to simian immunodeficiency viruses than the previously described HIV-1, despite a similar biology. The HIV-lentivirus phylogenetic relationship has broad implications for the AIDS disease process and has given new importance to the study of the natural history and pathogenesis of animal lentiviruses in searching for clues to prevent the spread of AIDS.

Association of human immunodeficiency virus infection and autoimmune phenomena

Patients infected with human immunodeficiency virus have a variety of presentations including fevers, lymphadenopathy, rash, renal dysfunction, and neurologic and hematologic disorders. Many of these features are also seen in patients with systemic lupus erythematosus (SLE). Herein are described five patients ultimately diagnosed as having acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) in whom the differential diagnosis included SLE because of multi-system disease and autoimmune phenomena, especially positive antinuclear antibodies. Serum samples from 151 consecutive patients with AIDS or ARC were examined and 19 with low titer-positive antinuclear antibodies were found (17 at 1:20 and two at 1:160). These observations suggest that SLE and human immunodeficiency virus infection may share clinical and serologic features.

Treatment of the neuromuscular complications of human immunodeficiency virus infection

Neuromuscular disorders are increasingly being reported in individuals with human immunodeficiency virus (HIV) infection. The majority of these disorders resemble diseases occurring in HIV-seronegative patients and include inflammatory demyelinating polyneuropathies, multiple mononeuropathies, and polymyositis. In HIV-seronegative patients, these diseases are believed to be immune system-mediated. It is likely that similar pathogenic mechanisms are present in HIV-seropositive patients and reflect an altered immune system caused by viral infection and the loss of CD4 cells. Therapy is similar in both seropositive and seronegative patients with inflammatory demyelinating polyneuropathies, but plasmapheresis is preferred in seropositive patients as it is less likely than corticosteroids to induce further immunosuppression. Distal sensory neuropathy is characteristic in patients infected with HIV, especially those with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex, and may be a consequence of HIV infection. Therefore, antiviral agents may have a therapeutic role for this disorder.

Neuropsychiatric consequences of AIDS

As part of a study in progress, neuropsychological tests have been administered to 13 patients with clinical acquired immunodeficiency syndrome, 9 human immunodeficiency virus-seropositive patients, 4 seropositive patients with chronic active hepatitis, 5 seronegative patients with chronic active hepatitis, and 6 healthy controls. Consistent with findings in earlier patient and control groups, the acquired immunodeficiency syndrome patients had substantially lower scores on a variety of cognitive tests. Although the acquired immunodeficiency syndrome group is not education-matched at present, the results are nonetheless consistent with impairments of language function and timed, self-paced performance. Test results obtained may reflect focal and global cognitive impairment as well as motivational decrements in patients with the acquired immunodeficiency syndrome relative to seropositive patients or controls.

Host and viral genetic factors which influence viral neurotropism

This chapter reviews host and viral genetic factors that influence viral neurotropism. It highlights a few recent insights that have been gained into the molecular and genetic basis for viral tropism, with specific emphasis on the factors that appear particularly relevant to understanding the basis for the tropism of viruses for the nervous system. The chapter discusses the way by which host genes, acting through a variety of mechanisms, can influence the susceptibility or resistance of animals to neurotropic viruses. It also reviews investigations concerning the role played by individual viral genes and the proteins they encode in determining specific pathways of viral spread to the central nervous system in the infected host. The chapter presents several examples illustrating the current state of knowledge concerning the nature of viral cell attachment proteins and host cell receptors for neurotropic viruses. It also presents examples of the way by which specific viral genetic elements such as enhancers can act to determine the cell-specificity of certain neurotropic viruses.

AIDS and dementia: a quantitative neuropsychological study of unselected Danish patients

Retrospective studies of hospitalized patients with the acquired immune deficiency syndrome (AIDS) have indicated that dementia occur in the majority of cases. In order to study the occurrence of dementia among AIDS patients, we conducted a controlled study of 16 unselected cases with a battery of neuropsychological tests known to be sensitive to brain damage of various etiologies. Except for fatigue, mental complaints and neuropsychiatric signs of dementia were generally sparse. As a group, the AIDS patients' performance in the neuropsychological tests did not differ from that of matched, healthy controls. Based on analyses of individual test results only one patient performed significantly inferior to what should be expected. The diagnosis of dementia should not be ascribed to AIDS victims on account of non-specific psycho-behavioral deviations that may represent a normal psychologic reaction to the disease, extreme fatigue, or both. Further, frequency measures of dementia in AIDS, based on large, unselected groups and with sufficient control, are still lacking. However, our study indicates that dementia is a less frequent complication of AIDS than so far assumed.

The metabolic pathology of the AIDS dementia complex

A progressive dementing illness, the AIDS dementia complex (ADC) is the most frequent neurological complication of the acquired immunodeficiency syndrome. Characteristic alterations in regional cerebral metabolic rate for glucose (rCMRGlc), associated with the presence or progression of ADC, were demonstrated by [18F]fluorodeoxyglucose/positron emission tomography in 9 of 12 patients with ADC compared with 18 normal volunteer subjects. In these 9 patients, two distinct patterns of regional metabolic activity were highly correlated with intersubject gray matter rCMRGlc variation and with disease severity as assessed by neuropsychological testing. Relative subcortical (thalamus and basal ganglia) hypermetabolism was characteristic of early ADC, and disease progression was accompanied by cortical and subcortical gray matter hypometabolism.

Detection of human immunodeficiency virus (HIV) genome from the lymphocytes of homosexual men

Human immunodeficiency virus (HIV) is the primary etiological agent of acquired immunodeficiency syndrome (AIDS). This virus can be transmitted by blood or blood products. Homosexual males (HM) are regarded as one of the high-risk groups for AIDS. Lymphocytes obtained from HM were used for cocultivation with fresh HIV antibody negative lymphocytes. The presence of virus particles was monitored by reverse transcriptase (RT) activity. Three out of eleven donors were found to have reverse transcriptase activity. All three donors were also found to be HIV antibody positive. HIV DNA from infected cells was detected by dot blot hybridization. The number of genome per cell is low. The correlation between RT activity and the cytolytic effect of HIV will be discussed.

[Cerebrospinal fluid in acquired immunodeficiency syndrome. Analysis of 50 cases]

Cerebrospinal fluid (CSF) was analysed in 50 AIDS patients in this investigation. CSF analysis included: pressure, aspect, colour, cytology (cell number, cytomorphology, and lymphocyte subpopulations), proteins concentration and their electrophoretic distribution, chloride and glycosis concentration, GOT and LDH activity, immunology for cysticercosis, syphilis and toxoplasmosis, bacteriology, and mycological examinations (direct, cultures, Cryptococcus neoformans antigen test). Diagnostic changes were: lymphoma cells in one patient, cryptococcosis in 10, toxoplasmosis in 4, candidiasis in 1, and syphilis in 3. Cryptococcosis occurred in association with toxoplasmosis in one patient who developed syphilis in the follow-up; oligoclonal distribution of gamma globulins occurred in this case. In another case of cryptococcosis, candidiasis appeared during the course of the disease. Changes in the CSF composition observed are discussed in order to evaluate: aspects of CSF inflammatory response in report to immunodeficiency; blood-brain barrier involvement; CNS damage; intracranial mass effects.

Human immunodeficiency virus-associated meningitis. Clinical course and correlations

Fourteen patients infected with human immunodeficiency virus (HIV) had a lymphocytic pleocytosis unexplained by secondary pathogens or neoplasms. Three men had prior diagnoses of Kaposi's sarcoma; none had acquired immune deficiency syndrome-defining opportunistic infections. Two patterns of illness were observed. Seven men had an acute, self-limited illness that was often accompanied by meningeal findings. The other seven had chronic headaches without signs of meningeal irritation and had less marked abnormalities of cerebrospinal fluid (CSF) cell count and protein. Encephalopathy was a finding in only one of 14 patients. In four of five CSF specimens studied, HIV was recovered. HIV has been associated with acute meningitis at the time of seroconversion and can apparently also cause sporadic episodes of acute or chronic meningitis in patients with prior infection and relatively preserved immune function. Both the clinical presentation with predominant headache rather than encephalopathy and the presence of CSF inflammation differentiate this syndrome from other HIV-related neurologic complications.

Paranoid psychosis as the first presentation of a fulminating lethal case of AIDS

A 34-year-old heterosexual intravenous drug abuser presented with a paranoid psychosis and was subsequently found to have the Acquired Immune Deficiency Syndrome (AIDS). The patient died 14 days later of generalised septicaemia. The case is reported and the aetiology and pathogenesis of the organic psychosis are discussed. It is anticipated that similar psychiatric manifestations will occur as the AIDS epidemic increases.

AIDS-related psychiatric disorder

The background to HIV infection, its mode of transmission, and its neurological and psychiatric complications are described. The management of AIDS-related psychiatric disorder and problems encountered among staff involved in the management of patients suffering from AIDS are considered. There is a need for appropriate educational programmes. Although the incidence of AIDS in the UK has been appreciably lower than in many other countries, there are no grounds for complacency; psychiatric disorder associated with HIV infection will be encountered much more frequently in the future. Psychiatric staff are urged to inform and prepare themselves in anticipation of this development.

Host and viral factors that influence viral neurotropism I. Viral cell attachment proteins and target cell receptors

Since the time of Charcot, over a century ago, it has been recognized that the clinical signs and symptoms produced by viral illnesses involving the CNS are due in large part to the specific regions of the nervous system injured. As the list of viruses capable of infecting the CNS expanded rapidly during the earlier part of the 20th century, so too did the recognition that individual viruses exhibited specific affinities for particular regions of the nervous system, and often for particular cell types within these regions. In this part of our review we will focus specifically on the role played by the interaction between specific viral proteins (‘cell attachment proteins’) and receptors on target cells in determining the tropism of certain viruses for the CNS. In a subsequent article, the role of host genes, the site of entry and route of spread of virus, and the contribution of tissue-specific viral genes (enhancers) to viral neurotropism will be reviewed.

The acquired immunodeficiency syndrome in intravenous drug abusers and patients with a sexual risk: clinical and postmortem comparisons

Clinical and necropsy findings in 13 intravenous drug abusers who died of the acquired immunodeficiency syndrome (AIDS) were reviewed and compared with findings in eight patients who acquired the infection through sexual exposure, the most common mode of transmission in AIDS. No differences were found in lymphocyte counts or duration of survival, despite reports that the degree of immunosuppression in intravenous drug abusers with AIDS differs from that in homosexuals. Neoplasms were found in 25 per cent of patients with sexual risks, but not in any drug abusers (0 per cent). Two opportunistic infections (toxoplasmosis and cytomegalovirus pneumonia and esophagitis) were more common in the intravenous drug abuser group. Although cytomegalovirus has been associated with Kaposi's sarcoma, this association was not found in this study. The postmortem findings in both groups were otherwise similar.

Inactivation of human immunodeficiency virus by Betadine

Human immunodeficiency virus (HIV), the etiological agent of the acquired immunodeficiency syndrome (AIDS), was treated with either Betadine (povidone-iodine) Solution or Betadine Surgical Scrub. HIV inactivation was analyzed using the viral reverse transcriptase assay or by observing the cytopathic effect produced in HIV-infected, H-9, T-cell cultures. The minimum effective Betadine dose was 0.25% for complete inactivation of HIV that was treated for various time intervals (immediate vortex to ten minutes). The titer of HIV stocks used in these experiments (10(5) TCID50 per mL) was greater than amounts generally detected in clinical specimens. Our results provide a rationale for the use of povidone-iodine as a topical antiseptic against HIV in the clinic or laboratory.

Transport of infectious reovirus into bile: class II major histocompatibility antigen-bearing cells determine reovirus transport

We have previously demonstrated that mammalian reovirus type 1 enters the bile and gut lumen after systemic administration. In the present study, we showed that Kupffer cell uptake is essential for the transport of reovirus into the bile. Furthermore, class II major histocompatibility antigen (I-A)-bearing cells are a major determinant for the transit of reovirus from the hepatic environment, as well as from the intestine, during the course of systemic infection. These findings may provide an approach to the control of viral pathogens that cause systemic disease by selective utilization or modification of I-A-bearing cells.

Human immunodeficiency virus long terminal repeat responds to T-cell activation signals

Human immunodeficiency virus (HIV), the causative agent of AIDS, infects and kills lymphoid cells bearing the CD4 antigen. In an infected cell, a number of cellular as well as HIV-encoded gene products determine the levels of viral gene expression and HIV replication. Efficient HIV-replication occurs in activated T cells. Utilizing transient expression assays, we show that gene expression directed by the HIV long terminal repeat (LTR) increases in response to T-cell activation signals. The effects of T-cell activation and of the HIV-encoded trans-activator (TAT) are multiplicative. Analysis of mutations and deletions in the HIV LTR reveals that the region responding to T-cell activation signals is located at positions -105 to -80. These sequences are composed of two direct repeats, which are homologous to the core transcriptional enhancer elements in the simian virus 40 genome. Our studies reveal that these elements function as the HIV enhancer. By acting directly on the HIV LTR, T-cell activation may play an important role in HIV gene expression and in the activation of latent HIV.

Antiviral therapy in AIDS. Clinical pharmacological properties and therapeutic experience to date

The rapid spread of human immunodeficiency virus (HIV) infections and the grim outcome of these infections have focused interest on the possibilities for medical intervention. The end-stage of these infections, acquired immune deficiency syndrome (AIDS), was first recognised in 1981, and the causative agent isolated in 1983. Already several antiviral drugs have been investigated. One initially promising drug, suramin, was found to have a net harmful effect but another, zidovudine (azidothymidine) has been shown to prolong life in AIDS patients. The properties of these and several other antiviral drugs such as antimoniotungstate (HPA-23), foscarnet (phosphonoformate) ribavirin, dideoxynucleotides, and interferons, are reviewed. The role of immunomodulating modalities such as plasmapheresis, bone marrow transplantation, thymosin, interleukin-2, inosine pranobex (isoprinosine), and cyclosporin are also discussed. None of the currently available drugs hold promise as monotherapy. Through analysis of the experience with these drugs and the increasing knowledge of HIV pathogenesis, new drugs can be designed. It seems increasingly clear that drugs will eventually have to be used in combination in order to reduce toxicity, exploit therapeutic synergy, and reduce the risk of HIV resistance. The theoretical and experimental background for such combinations are currently being elucidated.

Requests for psychiatric consultation concerning 22 patients with AIDS and ARC

Psychiatric consultation was requested for 22 of 150 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) admitted to St Vincent's Hospital, Sydney. The mean age of the patients was 35 years and all were homosexual or bisexual men. Ten patients had an organic brain syndrome: six as a result of cerebral opportunistic infection, two due to metabolic or iatrogenic causes and two apparently due to the direct neurotropic effects of the human immunodeficiency virus (HIV). Hallucinations and delusions were documented in five patients, of whom two had symptoms that fulfilled the criteria for a diagnosis of functional psychosis. Four patients were diagnosed as having adjustment disorder-depressive mood and one patient may have had a major depressive illness. Marked denial of illness was seen in two patients and four had markedly slow mentation with only mild or no evidence of cognitive impairment. It is concluded that patients with AIDS may have a wide variety of neuropsychiatric manifestations.

Functional interaction and partial homology between human immunodeficiency virus and neuroleukin

Dementia is common in patients with AIDS, but the mechanism by which the human immunodeficiency virus type 1 (HIV-1) causes the neurological impairment is unknown. In this study the possibility that an antigen of HIV-1 suppresses neuronal responses to neurotrophic factors was examined. Both HIV-1 and a related retrovirus, simian immunodeficiency virus (SIV), inhibited the growth of sensory neurons from chick dorsal root ganglia in medium containing neuroleukin (NLK) but not in medium containing nerve growth factor. An unrelated type D retrovirus, simian acquired immunodeficiency syndrome virus, did not affect the growth of neurons in the presence of either neurotrophic factor. The inhibition by HIV-1 of neuron growth in the presence of NLK was found to be due to the gp120 envelope glycoprotein. Regions of sequence homology between gp120 and NLK may account for this inhibitory property of gp120 and functional interactions between gp120 and NLK may be important in the pathogenesis of the AIDS dementia complex.

Human immunodeficiency virus infection of the developing human nervous system

Human immunodeficiency virus (HIV), the etiologic agent of acquired immune deficiency syndrome (AIDS) and AIDS-related complex, has recently been implicated as a factor in the development of AIDS-related neurologic dysfunction and may be responsible for an increasing number of neonatal immunologic and neurologic disorders. However, as yet there is no model system available to investigate the interaction of HIV with the developing human nervous system in vitro. To approximate the intracellular events associated with HIV infection of the human fetus nervous system we infected cells obtained by enzymatic dissociation of aborted human fetus dorsal root ganglia and their attached spinal roots and nerves. The expression of the HIV gag gene protein products (p17 and p24) was detected in a subpopulation of cells with a nonneuronal morphology, reaching a maximum within 3 days. Although 70% of the nonneuronal cells were p17- and p24-positive 3 days after infection, a majority of the cell population survived acute HIV infection, with the expression of p17 and p24 decreasing below the limit of detection by 12 days postinfection. This system may prove useful for examining the neuropathology and neurobiology of acute, persistent, or latent HIV infection of the developing human nervous system.

Pediatric human immunodeficiency virus infection and its cutaneous manifestations

Acquired immunodeficiency syndrome was first observed in children in 1982. Human immunodeficiency virus (HIV) is now known to be the etiologic agent of this disease complex. Children acquire the viral infection in utero or perinatally, or by receiving contaminated blood products. The cutaneous manifestations include persistent oral thrush, herpes simplex, herpes zoster, molluscum contagiosum, and a variety of fungal and bacterial skin infections. Vasculitis, unusual drug eruptions, and cutaneous manifestations of nutritional deficiencies are also seen.

Non-cytocidal natural variants of human immunodeficiency virus isolated from AIDS patients with neurological disorders

To understand the mechanism of HIV-mediated neuropathology five viral isolates were obtained from four AIDS cases with central nervous system manifestations as the primary involvement. The isolates were identified as HIVs by antigenic cross-reactivity and nucleic acid hybridizations to HIV-specific antibodies and DNA probes. The replication and cytopathic properties of these isolates were studied and compared with lymphadenopathy-associated virus (HIVLAV). All isolates had replication competence equivalent to LAV, but four isolates did not kill T4 (CD-4) cells. This isolation of non-cytocidal natural variants of HIV raises the possibility that in some AIDS cases the neurological disorders might be due to HIV variants that are non-cytocidal to T4 cells. The results also indicate that virus replication and cytotoxicity are not always concordant functions in HIV.

Pathogenesis of HIV and its implications for serodiagnosis and monitoring of antiviral therapy

Human immunodeficiency virus (HIV) is lymphotropic and neurotropic. In vivo clinical and immunological abnormalities develop in a large proportion of long-term HIV antibody seropositive persons. Different stages of HIV infection are marked by expression of HIV genes, production of HIV antibodies, formation of antigen/antibody complexes and clearance of such complexes. Transient HIV antigenemia appearing generally 6-8 wk prior to HIV antibody (HIV-Ab) seroconversion and lasting 3-4 mth is generally seen in acute infection. IgM antibodies predominantly to core proteins may occasionally be detectable when, or just before, IgG antibodies appear. If IgG antibodies to both envelope and core proteins persist in the absence of HIV-Ag the short-term prognosis is relatively good. However, HIV-Ag seroconversion may appear at any time after HIV-Ab seroconversion. Progression to AIDS is strongly associated with declining or absent levels of IgG antibodies to p24. IgG2 and IgG4 antibodies to HIV, which are mainly directed to p24, disappear most dramatically. Titers of antibodies to HIV p24 below 64 are strongly associated with the presence of HIV antigen and a poor clinical outcome. HIV antigen was detected frequently in sera from children in all stages of infection in contrast to adults whose sera were generally HIV-Ag negative when asymptomatic and positive when AIDS was apparent. HIV antigen may be less efficiently detected with the present assays in sera from regions where the prototype strains of HIV (HTLV-III and LAV) are less prevalent, like Central Africa. Persistence of HIV-Ag in cerebrospinal fluid (CSF) appears to be pathognomonic for progressive encephalopathy, particularly in children. Levels of HIV-Ag in serum, and possibly in CSF, can be decreased by nucleoside analogues, such as AZT. This indicates HIV-Ag and possibly antibody to HIV core protein p24 as suitable markers for selecting individuals for antiviral therapy as well as monitoring the efficacy of such therapy.

Intra blood-cerebrospinal fluid-barrier detection of hepatitis B virus

Hepatitis B, a major public health concern worldwide, is caused by hepatitis type B virus, a hepdnavirus that infects only human and certain nonhuman primates, and replicates strictly in hepatocytes. By using the techniques of slot and Southern blot DNA hybridization, and electron microscopy, the presence of HBV was identified in the cerebrospinal fluid of three affected individuals.