Failure of adjunctive cytomegalovirus intravenous immune globulin to improve efficacy of ganciclovir in patients with acquired immunodeficiency syndrome and cytomegalovirus retinitis: a phase 1 study

Six men with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis, treated with combined ganciclovir induction therapy and hyperimmune globulin (CMV-IGIV) for 10 days followed by CMV-IGIV alone, had a median time to retinitis progression shorter (7 days) than had eight historical controls given ganciclovir maintenance therapy (54 days; P = 0.06) and similar to that in eight controls given ganciclovir for 10 days only (19 days; P = 0.97). CMV-IGIV, which also failed to inhibit CMV replication in blood and urine, did not appear to add markedly to the efficacy of ganciclovir in acquired immunodeficiency syndrome-associated CMV retinitis.

Comparative recovery of cytomegalovirus from saliva, mucolysed induced sputum, and bronchoalveolar lavage fluid from patients at risk for or with acquired immunodeficiency syndrome

The recovery rates of cytomegalovirus from mucolysed induced sputum samples and bronchoalveolar lavage fluid obtained from individuals at risk for or with acquired immunodeficiency syndrome were compared. It was demonstrated that cytomegalovirus could be reliably recovered from mucolysed induced sputum, and such recovery was highly predictive of recovery from bronchoalveolar lavage samples obtained from the same individual.

Comparative assessment of antiretrovirals in human monocyte-macrophages and lymphoid cell lines acutely and chronically infected with the human immunodeficiency virus

We compared the efficacy of 3 antiretrovirals in cultured human peripheral blood monocyte-derived macrophages and lymphoid cells infected with the human immunodeficiency virus (HIV). Zidovudine (greater than 0.01 micrograms/ml) or foscarnet (greater than or equal to 100 micrograms/ml) consistently inhibited HIV replication (p24 antigen production) in acutely infected macrophages by more than 90%; alpha interferon (1,000 units/ml) inhibited HIV replication by 88-99%. Drug efficacy was equal in lymphoid cells and monocyte-derived macrophages. However, these antiretrovirals even in high concentration only minimally inhibited chronic, established HIV infection: while zidovudine (0.01 micrograms/ml) inhibited infection by over 90% in acutely infected macrophages and lymphoid cells, 50 micrograms/ml of this antiretroviral produced only 19-55% inhibition of HIV replication in chronically infected cells. Slot-blot analysis of HIV RNA was concordant with the p24 antigen data. Acutely infected macrophages are as susceptible to the inhibitory effects of antiretrovirals as lymphoid cells; however, chronically infected macrophages (which probably constitute the main in vivo reservoir for HIV) are several orders of magnitude more resistant.

Isolation and characterization of a multipotent clone of human embryonal carcinoma cells

Histopathological studies suggest that the stem cells of human teratomas may be classified into two major categories: nullipotent stem cells, and multipotent stem cells, capable both of self-renewal and differentiation into a wide range of somatic and extraembryonic cell types. We have isolated a multipotent stem cell clone from the human teratoma cell line GCT 27, and compared its properties to a nullipotent clone derived from the same strain. The multipotent clone GCT 27 X-1 gave rise to colonies of mixed cell morphology in vitro. Analysis of cell surface, cytostructural and extracellular matrix markers in GCT 27 X-1 cells showed that the stem cells of this line were very similar in phenotype to nullipotent cells. The two cell clones were predominantly hypotriploid, and contained several marker chromosomes in common. GCT 27 X-1 was feeder-cell-dependent for continuous growth in vitro; removal of the feeder layer resulted in differentiation of the stem cells into a variety of cell types, some with characteristics of extraembryonic endoderm, others showing neuronal properties. When transplanted into nude mice, GCT 27 X-1 cells gave rise to teratocarcinomas containing embryonal carcinoma stem cells, and many other cell types: yolk sac carcinoma cells; cells producing alphafetoprotein or human chorionic gonadotrophin; glandular, columnar, cuboidal, and squamous epithelium; primitive mesenchyme and cartilage; neuroectodermal cells. Nullipotent GCT 27 C-1 cells could form colonies in the absence of feeder layers, but multipotent GCT 27 X-1 cells could not. While a range of known growth factors and related substances failed to substitute for feeder layers in supporting the growth of GCT 27 X-1 stem cells, supernatants from yolk sac carcinoma cell line GCT 44 could partially replace the feeder cell requirement. Thus, the results revealed a basic difference in growth control between these multipotent and nullipotent human embryonal carcinoma cells, and suggested a possible paracrine regulatory pathway between multipotent stem cells and yolk sac carcinoma cells.

Comparison of the human immunodeficiency virus type 1 and 2 proteases by hybrid gene construction and trans-complementation

To determine the cleavage specificity of the proteases of the type 1 and 2 human immunodeficiency viruses (HIV-1, HIV-2), we interchanged this domain of the polymerase (pol) genes and analyzed the maturation programs of the chimeric polyproteins in an Escherichia coli expression system. In both cases, release of reverse transcriptase and integrase was observed, together with the respective 10-kDa protease form resulting from autocatalysis, although the maturation proceeded less efficiently compared to the homologous system. In further experiments, the ability of both HIV-1 and HIV-2 proteases to release in vivo gag p24 from an in-frame fusion of the full length gag and protease precursors was analyzed. In either case, p24 was released, albeit with greater efficiency in the heterologous gene construction. In vitro mixed lysate experiments with the HIV-1 gag precursor furthermore demonstrate that both enzymes respond to the aspartyl proteinase inhibitor pepstatin A. Taken together, these results illustrate that although different cleavage recognition sequences exist for HIV-1 and -2, they are amenable to the proteases of both viruses, but additionally that subtle differences in the mode of action of both enzymes are observable.

Effects of selective depletion of L3T4+ T-lymphocytes on herpes simplex virus encephalitis

The L3T4 surface molecule defines a subset of murine lymphocytes which are homologous to CD4+ lymphocytes in humans, and are functionally characterized as "helper/inducer" cells. To determine the role of helper/inducer lymphocytes in the host defense against herpes simplex virus type 1 (HSV-1) encephalitis, we utilized a monoclonal antibody to selectively deplete L3T4+ lymphocytes from BALB/c mice prior to experimental HSV infection. Susceptibility to HSV was only minimally increased by the depletion of L3T4+ cells, although mice receiving anti-L3T4 were profoundly immunosuppressed; splenic lymphocytes did not respond to stimulation by virus antigen in vitro, and L3T4+ lymphocyte-depleted mice failed to produce antibodies to HSV-1. However, mice receiving anti-L3T4 had a prolonged increase in natural killer cell activity following HSV infection as compared to controls. These data demonstrate that L3T4+ lymphocytes contribute minimally to host resistance to acute neural HSV infection, even though elimination of these lymphocytes markedly inhibits the genesis of immune responses.

Effects of L3T4+ lymphocyte depletion on acute murine cytomegalovirus infection

We examined the role of T lymphocytes bearing the L3T4 phenotype in acute murine cytomegalovirus (MCMV) infection. In vivo administration of rat IgG2b monoclonal antibody (MAb) GK 1.5 was used to deplete mice of L3T4+ lymphocytes during acute MCMV infection. Unlike the saline-treated controls that resolved their infections, mice receiving the MAb developed persistent and high levels of virus in the salivary gland, lung and spleen. The production of antibody to MCMV was delayed and the titres achieved were markedly less than in the controls. Despite the higher levels of virus replication, there was no increase in mortality seen in animals treated with the MAb. Following intraperitoneal challenge with MCMV, depletion of L3T4+ lymphocytes was protective, increasing the dose of MCMV required to produce death. These data indicate that T lymphocytes of the L3T4 phenotype influence the degree of MCMV replication during acute infection and may contribute to mortality following intraperitoneal virus challenge.

Diagnosis of coronary artery disease using thallium imaging: tomographic versus planar imaging

Coronary artery disease was evaluated with tomographic and planar thallium imaging in 31 subjects who had undergone coronary angiography for assessment of chest pain syndrome. Coronary arteriography revealed significant coronary artery disease in 17; and 14 had normal coronary arteries. The sensitivity and specificity for planar imaging was 71% and 79%, and that for tomography, 94% and 79% respectively. The sensitivity and specificity figures for individual coronary artery lesion detection for planar imaging were 87/83 for LAD, 33/100 for LCX and 50/86 for RCA respectively, and for tomography the figures were 87/87 for LAD, 33/95 for LCX and 90/76 for RCA respectively. The use of coronary arteriography as a gold standard was considered by assessing its interobserver variability, which was 16%. The interobserver variability for thallium imaging was 8% and 3% respectively for tomographic and planar acquisitions.

Pharmacokinetics of intermittently administered intravenous foscarnet in the treatment of acquired immunodeficiency syndrome patients with serious cytomegalovirus retinitis

Foscarnet has been shown to be active in vitro against the human immunodeficiency virus and all human herpesviruses including cytomegalovirus (CMV). A pharmacokinetic study was carried out as part of a clinical trial designed to evaluate the safety and efficacy of intermittently administered intravenous foscarnet for the treatment of CMV retinitis. Eight patients with acquired immunodeficiency syndrome and serious CMV retinitis received 2-h intravenous infusions of foscarnet at a dosage of 60 mg/kg of body weight every 8 h for 14 days. Serial plasma samples were collected on days 3 and 14 of therapy, and foscarnet concentrations were determined by high-pressure liquid chromatography. On day 3 of therapy, the mean (+/- standard deviation) peak and trough levels in plasma were 509 (200) and 98 (29) microM, respectively, while on day 14 levels were 495 (149) and 126 (59) microM. The mean clearance in plasma on days 3 and 14 were 1.9 (0.6) and 1.7 (0.9) ml/min per kg, respectively. On day 14, the mean half-life was 4.5 (1.2) h and the volume of distribution was 0.74 (0.60) liter/kg. As the half-life and the clearance of foscarnet in plasma correlated with changes in renal function, dosage adjustments must be made for patients with decreased renal function.

The independent action of radiation and cisplatin on the survival or recovery of human normal or tumour cells in vitro or in vivo

Recovery from radiation- or cisplatin-induced lethal damage has been studied in euoxic normal human foetal lung fibroblasts (HFL cells) that remain viable for at least 20 days in plateau-phase culture. After a 1 hour treatment with cisplatin the half-time of recovery was about 2 days. By contrast recovery after radiation was more rapid with half-times of approximately 10 h. There was no further measurable recovery after 2 days. With either agent the recovery ratios (RR) were dose-dependent but recovery (following treatment with equitoxic doses of the two agents) was appreciably greater after cisplatin (RR approximately 123 after 40 microM for 1 h) than after radiation (RR approximately 15 after 900 cGy). When radiation (900 cGy) was combined with cisplatin (40 microM for 1 h) the cell survival, measured at 5 days or later times after the treatments, was not significantly less than that predicted by the additive, independent effects of both agents (calculated as the product of their respective effects on cell survival) irrespective of whether cisplatin was given 1 h before, during or for 1 h immediately after radiation. In euoxic, exponentially growing HFL or HeLa cells there was no evidence that combinations of cisplatin and radiation gave more than additive toxic effects in the protocols tested. The combined effects of cisplatin or carboplatin and whole-body irradiation given 45 min later, on human melanoma cells (assessed by their colony-forming abilities in vitro) growing in thymectomised mice, were essentially the same as that predicted by the additive, independent effects of the two agents.

Foscarnet treatment of cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome

Ten patients with acquired immunodeficiency syndrome with newly diagnosed cytomegalovirus (CMV) retinitis were treated with an induction regimen of intravenous foscarnet, 60 mg/kg of body weight, administered as a 2-h infusion and repeated every 8 h for 14 days. At the end of induction, 9 of 10 patients had stabilized (no new retinal lesions and stable old lesions [7 patients]) or improved (decreased retinal opacification [2 patients]). All eight patients with CMV in urine or blood upon entry into the study had negative urine and blood cultures at the end of induction. After induction therapy, seven patients continued maintenance foscarnet therapy, 60 mg/kg as a single daily infusion, 5 days/week. In six patients, retinal lesions increased in size after 2 to 32 weeks of maintenance therapy. One was invaluable because a retinal detachment developed. Only 9 of 42 blood and urine cultures obtained during maintenance foscarnet therapy yielded CMV, compared with 7 of 14 obtained prior to the initiation of foscarnet induction therapy (P = 0.04). Foscarnet toxicity was mild and infrequent: elevation in serum creatinine by 0.5 to 1.3 mg/dl over the base line (two patients), muscle twitching (three patients), hemoglobin decrease by 1 mg/dl (two patients), nausea (two patients), absolute neutrophil count decrease by 50% (one patient), rise in serum phosphorus to greater than 5.5 mg/dl (four patients), and proteinuria (two patients). Intermittently administered intravenous foscarnet appears to be an effective, relatively nontoxic therapy for CMV retinitis. Additional studies to determine the optimal dosage for maintenance therapy are needed, as are comparative trials with ganciclovir.

Reliable confirmation of antibodies to human immunodeficiency virus type 1 (HIV-1) with an enzyme-linked immunoassay using recombinant antigens derived from the HIV-1 gag, pol, and env genes

An enzyme-linked immunoassay (ELISA) using six recombinant proteins corresponding to large segments of the human immunodeficiency virus type 1 (HIV-1) gag, pol, and env gene products (HIVAGEN; SmithKline Bio-Science Laboratories, Van Nuys, Calif.) was developed to confirm the presence of antibodies to HIV-1 in sera reactive in the whole-cell-derived virion screening ELISAs. Serum samples for testing were obtained from healthy seronegative blood donors and from the different categories of HIV-infected individuals (asymptomatic, acquired immunodeficiency syndrome [AIDS]-related complex, and AIDS). A positive reaction was defined as reactivity against an env and at least one other (either gag or pol) HIV-1 gene product; negative was defined as no reaction with any antigen; and indeterminate was defined as reactivity with gag or pol (or both) or with env alone. None of the 1,180 serum samples from healthy seronegative blood donors gave a positive result, and only 49 of these samples (4%) gave indeterminate results. The recombinant HIV-1 antigen ELISA panel identified seropositive individuals with a high degree of accuracy, as a positive reaction was seen with 99.3% of asymptomatic healthy seropositive individuals, 98.1% of patients with AIDS-related complex, and 90.4% of patients with AIDS. None of the 725 HIV-1-seropositive subjects had a negative test result. Reactivity with the Kp41 antigen, corresponding to an amino-terminal portion of the gp41 envelope glycoprotein, by itself demonstrated 100% sensitivity and specificity in distinguishing seronegative from seropositive sera. A subset of seronegative and seropositive samples were tested both with the recombinant HIV-1 antigen ELISA panel and by Western blot (Du Pont Co.). The recombinant HIV-1 antigen ELISA panel accurately identified more seropositive and seronegative samples and had fewer indeterminate results than did Western blot (interpreted by Du Pont criteria).

Foscarnet therapy for severe acyclovir-resistant herpes simplex virus type-2 infections in patients with the acquired immunodeficiency syndrome (AIDS). An uncontrolled trial

STUDY OBJECTIVE

To determine whether trisodium phosphonoformate (foscarnet) is efficacious in treating severe mucocutaneous disease due to acyclovir-resistant herpes simplex virus type-2 (HSV-2) infection in patients with the acquired immunodeficiency syndrome (AIDS).

DESIGN

Open-labeled drug administration to patients with AIDS and severe ulcerative disease due to acyclovir-resistant HSV-2 infection.

SETTING

Medical floors of acute care hospital.

PATIENTS

Four patients with AIDS who developed progressive ulcerative mucocutaneous lesions of the genitals, perineum, perianal region, or finger due to acyclovir-resistant, thymidine-kinase (TK)-negative strains of HSV-2.

INTERVENTION

Foscarnet, 60 mg/kg body weight intravenously every 8 hours (with reduced dosage for renal impairment), for 12 to 50 days.

MEASUREMENT AND MAIN RESULTS

All patients receiving foscarnet had dramatic improvement in their clinical findings with marked clearing of mucocutaneous lesions and eradication of HSV from mucosal surfaces.

CONCLUSION

Foscarnet may be an effective treatment for severe mucocutaneous disease due to acyclovir-resistant, TK-negative strains of HSV-2.

Dapsone, trimethoprim, and sulfamethoxazole plasma levels during treatment of Pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Evidence of drug interactions

STUDY OBJECTIVE

To examine the interaction between dapsone and trimethoprim in patients with the acquired immunodeficiency syndrome (AIDS).

DESIGN

Measurement of drug levels as part of an open study of dapsone alone and randomized, double-blind comparison of trimethoprim-dapsone with trimethoprim-sulfamethoxazole in treating Pneumocystis carinii pneumonia in patients with AIDS.

SETTING

County hospital and AIDS clinic.

PATIENTS

Eighteen patients treated with dapsone alone, 30 with trimethoprim-dapsone, and 30 with trimethoprim-sulfamethoxazole.

INTERVENTION

Dapsone, 100 mg/d; trimethoprim, 20 mg/kg body weight per day, and sulfamethoxazole, 100 mg/kg.d; administered for 21 days.

MEASUREMENTS AND MAIN RESULTS

Concentrations of dapsone were 40% higher in patients treated with trimethoprim-dapsone than in those treated with dapsone alone (2.1 compared with 1.5 micrograms/mL; P less than 0.05). Trimethoprimdapsone-treated patients had fewer treatment failures but more side effects and treatment terminations due to toxicity than those treated with dapsone alone. The concentration of trimethoprim was 48.4% higher in patients treated with trimethoprim-dapsone than in those treated with trimethoprim-sulfamethoxazole, (18.4 compared with 12.4 micrograms/mL; P less than 0.05). Discontinuation of therapy due to toxicity was commoner in the trimethoprim-sulfamethoxazole group (57% compared with 30%).

CONCLUSIONS

A bidirectional drug interaction exists between dapsone and trimethoprim, resulting in higher concentrations of each in the presence of the other.

The future of antiviral chemotherapy

Over the past two decades, alongside the production of vaccines against many viruses, effective drugs have been developed for many other common viral infections. Initially, many of these drugs were available only for topical application because of their toxicity. However, advances in our knowledge of viral replication and of the molecular and cellular mechanisms of antiviral action have identified virus-specific targets for chemotherapeutic intervention with fewer side effects.

Acyclovir-resistant, foscarnet-sensitive oral herpes simplex type 2 lesion in a patient with AIDS

We report the case of an immunocompromised patient with AIDS in whom developed a perioral and several intraoral HSV 2 lesions that persisted for more than 1 year. The virus was resistant to acyclovir but was sensitive to foscarnet. Viral isolates were thymidine kinase negative. The lesions resolved with intravenous foscarnet therapy given over a 15-week period, and when last seen, 8 months after foscarnet was discontinued, the patient had not had a recurrence.

Code of practice for the management of sheltered housing for sale

Discusses the background to the management of sheltered housing for sale, the main problems of management identified, the solutions proposed, the issues for management organizations, and the main points of the code of practice for the management of sheltered housing for sale introduced in 1989. Concludes that while the cost of implementing the code′s proposals will be passed on to lessees, cheap management is not appreciated so the image of residential property management should be improved: if not, more radical solutions will be called for.

Incidence of acute mountain sickness at intermediate altitude

The incidence of acute mountain sickness was determined by questionnaire in 454 individuals who attended week-long continuing medical education programs at ski resorts in the Rocky Mountains with base elevations of about 2000 m. As a control group, 96 individuals who attended continuing medical education programs at sea level in San Francisco completed similar questionnaires. Study subjects were classified as having acute mountain sickness when they reported three or more of the five possible cardinal symptoms: headache, insomnia, dyspnea, anorexia, and fatigue. Only symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. Acute mountain sickness-like symptoms occurred in 25% of subjects at 2000 m compared with 5% of subjects at sea level. The incidence of acute mountain sickness at 2000 m was greatest among subjects who had come from lower altitudes. Half of the subjects with symptoms took medication. The duration of symptoms was short, with 90% of all symptoms that were reported occurring in the first 72 hours. Acute mountain sickness is common at intermediate altitudes, and it is frequently severe enough to prompt self-medication.

Effects of dexamethasone on the incidence of acute mountain sickness at two intermediate altitudes

To test the value of dexamethasone acetate for ameliorating acute mountain sickness (AMS), we conducted a double-blind, randomized study that compared the effects of 4 mg of dexamethasone acetate or a placebo (given every six hours for six doses beginning at the time of exposure) at 2700 and 2050 m. Study subjects, who were recruited from health professionals who attended continuing medical education programs at ski resorts in the Rocky Mountains, were classified as having AMS when they reported three or more of the five usual symptoms (headache, insomnia, dyspnea, anorexia, and/or fatigue) on a single day. All symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. At 2700 m, there was a 50% decrease in the mean AMS symptom score in the dexamethasone group (0.94 +/- 1.11 vs 1.84 +/- 1.44 [mean +/- SD]) and the incidence of AMS was 20% of that in the control group (3/38 vs 14/35). At 2050 m, there was no difference between dexamethasone and a placebo in the mean AMS symptom score (1.52 +/- 1.50 vs 1.24 +/- 1.33) and the incidence of AMS (5/25 vs 4/25). Dexamethasone ameliorates the usual symptoms of AMS at 2700 m but not at 2050 m.

Release of interleukin 1 inhibitory activity (contra-IL-1) by human monocyte-derived macrophages infected with human immunodeficiency virus in vitro and in vivo

Infection of monocyte-macrophages with human immunodeficiency virus may be central to the pathogenesis of the acquired immunodeficiency syndrome. The ability of infected macrophages to prime T cells through IL-1 production was investigated in vitro. Purified human monocytes maintained in suspension culture were infected with strain HIV-DV. Intracellular expression of virus p24 antigen increased from undetectable levels immediately after infection to 13-59% of cells by 10-14 d; infected macrophages remained viable for up to 60 d. Supernatants collected between 14 and 20 d after infection were examined in the murine thymocyte co-mitogenesis assay and demonstrated to contain a potent IL-1 inhibitor, designated contra-IL-1. Contra-IL-1 activity was present in all supernatants examined after 4 d of infection, and peaked coincident with peak p24 antigen expression. Inhibitory activity was not present in uninfected cells. Contra-IL-1 activity eluted after gel filtration with an approximate molecular weight of 9 kD. Inhibitory activity was removed by exposure to heat or acid pH, or by incubation with chymotrypsin or staphylococcal V8 protease. Contra-IL-1 did not inhibit IL-2- or IL-4-dependent proliferation of murine T cell lines. Despite its ability to inhibit IL-1 activity, contra-IL-1 did not interfere with the binding of recombinant IL-1 beta to a fibroblast cell line. Contra-IL-1 inhibited the proliferation of normal peripheral blood mononuclear cells to both concanavalin A and tetanus toxoid; inhibition could be attenuated by the addition of exogenous IL-1. Messenger RNA extracted from infected macrophages was examined by Northern analysis for the presence of message to IL-1 beta. No message was apparent, suggesting that the presence of contra-IL-1 was not obscuring the concomitant release of IL-1. Infected macrophages stimulated with endotoxin generated readily detectable message for IL-1 beta. Spleen macrophages purified from two patients with AIDS complicated by immune thrombocytopenia spontaneously expressed p24 antigen in vitro and released contra-IL-1 activity into the media. Contra-IL-1 may contribute to the immune dysfunction of AIDS.