Alanine aminotransferase levels are not significantly elevated in patients with HIV/HBV co-infection and lamivudine resistance

In hepatitis B virus (HBV) monoinfection, alanine aminotransferase (ALT) levels are linearly correlated with HBV DNA levels and lamivudine resistance. In human immunodeficiency virus (HIV)/HBV co-infection, little is known about the association between ALT, HBV DNA, and lamivudine resistance. We assessed HBV DNA, lamivudine resistance and ALT levels in 45 time points in 11 patients with HIV/HBV co-infection during lamivudine-containing antiretroviral therapy. High HBV DNA levels (>10(6) copies/mL) and lamivudine resistance developed in 45% and 91% of patients, respectively. However, ALT levels were not elevated in the setting of high HBV DNA levels (mean ALT, 48 IU/mL) or lamivudine resistance (mean ALT, 44 IU/mL). HBV viraemia and lamivudine resistance during extended lamivudine-containing antiretroviral therapy are common in HIV/HBV co-infection, occurring in the absence of significant ALT elevations. In HIV/HBV co-infection, measurement of HBV DNA and HBV resistance mutations may identify HBV virological failure before biochemical changes and should be routinely used in the management of HIV/HBV co-infection.

A study of HIV RNA viral load in AIDS patients with bacterial pneumonia

We examined the effect of bacterial pneumonia on the magnitude of circulating plasma HIV RNA in HIV-infected patients. Serum samples from 13 adult HIV-infected patients (median CD4 count = 83 cells/microl) were assayed for HIV RNA using the reverse transcriptase polymerase chain reaction assay (a) before bacterial pneumonia, (b) during the acute phase, and (c) after the recovery from the disease. Patients remained on constant antiretroviral therapy: HIV RNA was detected in all samples tested. The medians before, during, and after bacterial pneumonia were 60,000 copies per ml, 245,000 copies per ml, and 84,000 copies per ml, respectively. All 13 patients had increased HIV RNA levels on developing pneumonia. There was a decline in the level of HIV RNA with recovery from pneumonia in 12 of 13 patients. The difference between the HIV RNA levels before and after pneumonia was not significant, nor was there significant difference in the CD4 counts before and after pneumonia. In conclusion, bacterial pneumonia is associated with a consistent, transient increase in HIV RNA of variable magnitude in AIDS patients. Interpretation of HIV RNA changes for clinical management of AIDS patients must take into account this reversible elevation during infections.

Changes in virus load markers during AIDS-associated opportunistic diseases in human immunodeficiency virus-infected persons

Human immunodeficiency virus (HIV) load markers are being used increasingly to monitor disease progression and evaluate antiretroviral therapy. This study examined plasma HIV RNA and p24 antigen levels before, during, and after 15 AIDS-associated opportunistic disease events in patients with AIDS (median CD4 cell count = 65/microL). Plasma HIV RNA was detected during 13 of the 15 events (median level before an event = 21,000 copies/mL). There was an increase in the level of plasma HIV RNA with the onset of an AIDS-associated opportunistic disease during 11 of 13 events for which HIV RNA was detectable (median level during an event = 145,000 copies/mL). There was a decline in the level of HIV RNA with the recovery from disease (median level after an event = 29,700 copies/mL). In contrast, there was no consistent or significant change in p24 antigen levels or CD4 cell counts with either the onset of or recovery from an event. Clinical interpretation of plasma HIV RNA changes must take into account this reversible elevation during AIDS-associated opportunistic disease.

Gender is not a factor in serum human immunodeficiency virus type 1 RNA levels in patients with viremia

We investigated gender as a factor in viral load measurements for human immunodeficiency virus-infected patients. Forty antiretroviral-therapy-naive, age- and CD4-matched women and men were tested for serum RNA and p24 antigen levels prior to antiretroviral therapy and at approximately 12 weeks after therapy. No gender differences were observed for these two markers of viral load.

Comparison of HIV type 1 RNA plasma viremia, p24 antigenemia, and unintegrated DNA as viral load markers in pediatric patients

Better surrogate markers need to be developed to evaluate therapy in HIV-infected children. This study evaluated plasma RNA, immune complex-dissociated p24 antigenemia, and unintegrated DNA (uDNA) in HIV-infected pediatric patients. Ten children were followed from initiation of nucleoside antiretroviral therapy at intervals up to 24 months. Prior to initiation of therapy, HIV RNA was detected in 10 of 10 patients (median, 76,000 Eq/ml), p24 antigen was detected in 8 of 10 patients (median, 193 pg/ml), and uDNA was detected in 6 of 7 patients (median, 10% uDNA). After 12 months the RNA decreased in all patients and became undetectable in six. In contrast, p24 antigenemia decreased in 6 of 10 patients, remained undetectable in 1, and increased in 3. HIV uDNA decreased in six of six patients and became undetectable in three. There was no overall change in CD4 cell count. Plasma RNA and uDNA levels are both sensitive markers of nucleoside therapy in children; however, they do not covary strongly.

Antiretroviral therapy is associated with a decrease in unintegrated HIV-1 DNA in pediatric patients

Good markers for monitoring the efficacy of antiretroviral therapy in children do not currently exist. This study examined the effect of antiretroviral therapy on human immunodeficiency virus (HIV-1) unintegrated DNA (uDNA), integrated DNA (iDNA), percent uDNA, immune complex dissociated (ICD) p24 antigenemia, and plasma viral titer. Seven children were followed at therapy initiation and at approximately 3- and 10-month intervals. HIV-1 uDNA was detected in all children prior to start of therapy (average percent uDNA, 43%). At 3 months, the percent HIV uDNA decreased in all patients to an average of 18% (p = 0.01) and at 10 months decreased to an average of 1%. In contrast, the amount of HIV iDNA was relatively constant after initiation of therapy. ICD HIV p24 antigen was detected in all patients prior to therapy (average, 538 pg/ml). Over the study period, the ICD p24 antigen level decreased in three patients and remained relatively unchanged in four patients. Plasma cultures of HIV-1 were positive in only one of the seven patients prior to therapy. Among the methods evaluated, measurement of uDNA was the only parameter which reliable decreased after initiation of nucleoside therapy.

Rapid decrease in unintegrated human immunodeficiency virus DNA after the initiation of nucleoside therapy

Better markers for determining therapeutic efficacy of antiretroviral drugs are needed for human immunodeficiency virus (HIV) infection. The amounts of unintegrated HIV DNA (uDNA) were sequentially determined in peripheral blood mononuclear cells (PBMC) from 20 HIV-infected patients starting nucleoside therapy. HIV copy number was determined using a quantitative polymerase chain reaction assay. Before therapy, 19 of 20 patients had detectable HIV uDNA. The average percentage of uDNA was 42%. After 1, 4, and 8 weeks of nucleoside therapy the average decreased to 23% (P < .001), 7%, and 3%, respectively. The amount of HIV uDNA decreased in all 19 patients during the first week and was undetectable in 14 by 8 weeks. Thus, measurement of HIV uDNA has many characteristics needed for a good marker of therapeutic efficacy of antiretroviral drugs, including detectability in a high proportion of patients, large and rapid response to initiation of therapy, and a biologically plausible mechanism.

Increased detection of human immunodeficiency virus antigenemia after dissociation of immune complexes at low pH

This study compared the number of patients with detectable human immunodeficiency virus (HIV) antigenemia after immune complex (IC) dissociation by established methods using either 0.5 NCl or 1.5 M glycine buffer. Without IC dissociation, HIV antigen was detected in 43% of patients. After dissociation, the HCl method detected only an additional 7% of patients (P = 0.09), while the glycine method detected an additional 34% (P < 0.001). However, care must be taken in setting the threshold of the standards, and confirmatory neutralization assays should be performed to ensure specificity of HIV antigen enzyme immunoassay after IC dissociation.

Quantitation of unintegrated HIV-1 DNA in asymptomatic patients in the presence or absence of antiretroviral therapy

The objective of this work was to determine the amount of unintegrated human immunodeficiency virus (HIV) DNA (HIV uDNA) in asymptomatic individuals in the presence or absence of antiretroviral therapy. Twenty-one healthy seropositive individuals with no history of any opportunistic infection or previous use of nucleoside antiretrovirals, and 9 similarly asymptomatic individuals who had initiated nucleoside antiretroviral therapy within the last 24 months were studied. All patients had CD4 lymphocyte counts above 400/microliters. All subjects administered antiretrovirals received 400-600 mg of zidovudine daily for 2-24 months. Two individuals additionally received 400 mg of dideoxyinosine (ddI) daily for 4 and 5 months. Patient peripheral blood mononuclear cells (PBMCs) were examined for integrated and unintegrated HIV DNA by a quantitative PCR assay. In addition, CD4 counts were measured, and free and immune complex dissociated p24 antigen was detected in plasma by ELISA. The mean percentage of HIV uDNA in asymptomatic individuals not on therapy was 59%, with 95% confidence limits from 50 to 69%. In contrast, patients on therapy had a mean of only 13% HIV uDNA, with confidence limits from 2 to 25% (p < 0.001). These findings indicate that a significant amount of HIV DNA in infected, healthy patients not on therapy is in the unintegrated form, and that the amount of HIV uDNA in asymptomatic patients on nucleoside therapy is much less. The amount of HIV uDNA in PBMCs deserves further study as a new marker of the efficacy of antiretroviral therapy.

Detection of human immunodeficiency virus type 1 RNA in plasma samples from high-risk pediatric patients by using the self-sustained sequence replication reaction

There is an urgent need for rapid and sensitive methods to assess human immunodeficiency virus (HIV) infection in infants and children. We evaluated an approach by using the self-sustained sequence replication reaction (3SR) to amplify HIV type 1 (HIV-1) RNA directly. The amplified RNA product was then detected by bead-based sandwich oligonucleotide capture hybridization and rare earth metal chelate time-resolved fluorescence. The sensitivity of this technology was determined to be less than 12 HIV-1 RNA copies with an amplification level of 10(10)-fold with purified HIV-1 RNA. Plasma samples from 19 high-risk pediatric patients younger than 5 years of age were examined, and results were compared with viral culture of patient plasma. Results from plasma culture and 3SR amplification agreed for 14 of these patients and disagreed for 5. Of the five samples which did not agree, four were positive by 3SR and negative by culture and one was positive by culture and negative by 3SR but became positive by 3SR at a subsequent testing. We conclude that 3SR amplification coupled with time-resolved fluorescence is a promising technology for investigating the relationship between the presence of HIV-1 RNA in plasma and progression of disease in HIV-infected pediatric patients. This technology should be important in the assessment of HIV-1 infection, in evaluating drug therapies, and in understanding the pathogenesis and transmission of the virus.

Human immunodeficiency virus infection of enterocytes and mononuclear cells in human jejunal mucosa

Intestinal malabsorption is a recognized cause of malnutrition in patients infected with human immunodeficiency virus. However, the relationships among human immunodeficiency virus infection, morphological changes in the intestine, and development of intestinal malabsorption are not well established. Nine patients infected with human immunodeficiency virus underwent tests of intestinal absorption and jejunal biopsies for morphometric measurements, enzyme assays, and virus detection by in situ hybridization. Steatorrhea and low lactase activities were found in more than 85% of the patients. All biopsy specimens were abnormal with reversal of the ratio of villus length to crypt depth in seven and enlarged enterocyte nuclear size in nine. Human immunodeficiency virus was detected in five jejunal biopsy specimens, within villus enterocytes of one patient who had the most severe malabsorption of the group and in four other biopsy specimens in mononuclear infiltrating cells of the lamina propria. These results suggest that human immunodeficiency virus infection of the small intestinal mucosa is an early event that is associated with altered enterocyte differentiation and function.

Laboratory tests used in diagnosis and treatment of AIDS

Detailed knowledge of the structure of the human immunodeficiency virus (HIV) triggered a rapid development of methods for diagnosing the infection. The enzyme-linked immunoadsorbent assay (ELISA) determining the presence of antibodies to the protein components of the virus in toto is highly sensitive and provides thus the basic screening approach. It is however somewhat less specific and therefore all positive results are verified by the Western blot method which detects individual HIV proteins and possesses a 99.9% specificity. In sporadic cases the latent period between HIV infection and the possibility to establish antibody response may extend to six months and even longer. The polymerase chain reaction (PCR) revealing the presence of DNA HIV in infected cells is suitable for detecting these seronegative patients. It is also the method of choice in diagnosing HIV infection in children of infected mothers since HIV antibodies are in newborns mostly of maternal origin. HIV antibodies, particularly the antigen p 24, can be quantified in serum by using ELISA. As their amounts correlate with the severity of the disease determination of antigen p 24 concentration is an indicator of the therapeutic efficacy of preparations such as AZT. The recently developed quantitative PCR is a further potentially valuable method for assessing the therapeutic effect since treatment should reduce the amount of cellular HIV DNA. With the exception of testing the sensitivity of HIV strains to antiretrovirus preparations, HIV cultures are rarely set up since they are technically demanding and involve a considerable risk.

Quantitation of human immunodeficiency virus DNA by using the polymerase chain reaction

The polymerase chain reaction was used to measure the DNA copy number of human immunodeficiency virus (HIV). Differences in polymerase chain reaction amplification efficiency were controlled by amplifying known amounts of HIV DNA in parallel with samples. This technique is a sensitive, accurate, and reproducible method for the quantitation of HIV DNA.

Detection of human immunodeficiency virus in infected CEM cells using fluorescent DNA probes and a laser-based computerized image cytofluorometry system

Quantitative nonradioactive methods to measure the human immunodeficiency virus (HIV) in individually infected cells are needed for the direct assessment of HIV infection, for the evaluation of antiviral chemotherapy and for testing the efficacy of vaccines. As a first step in accomplishing this goal, we built an argon ion laser-based computerized image cytofluorometry (ALCIC) system and determined this instrument's ability to quantitatively measure HIV nucleotides in infected lymphocytes. ALCIC consisted of a 43-mW argon ion laser connected to a Zeiss Universal microscope via a fiberoptic cable, a charged coupled-device video camera, a video frame grabber and array processor and a Micro Vax II computer using computer programs written in FORTRAN. HIV RNA and DNA were detected in infected CEM lymphocytes in culture by in situ hybridization using acetylaminofluorene (AAF)-labeled HIV-DNA probes, a rabbit anti-AAF antibody and a fluorescein-labeled goat anti-rabbit antibody. ALCIC measurements showed that 61% of the CEM cells were infected and that quantitative differences were distinguishable within this group. The levels of fluorescein isothiocyanate (FITC) fluorescence were sixfold or more greater than that observed with the same system using a 100-W mercury lamp for illumination; the improved intensity of the laser-based system is due to greater excitation intensity of the laser and the matching of the excitation spectrum to the peak wavelength of FITC. ALCIC has potential clinical value for determining the effect of antiviral agents on HIV infection and for assessing the susceptibility of different cell types to infection.

In situ detection of human immunodeficiency virus (HIV) nucleic acid in H9 cells using nonradioactive DNA probes and an image cytophotometry system

Rapid and sensitive nonradioactive methods to detect human immunodeficiency virus (HIV)-infected cells are needed in clinical medicine. We developed an in situ hybridization test using 2-acetylaminofluorene (AAF)-labeled HIV DNA as a hybridization probe. Hybridized probe was detected using rabbit anti-AAF antibody, followed by alkaline phosphatase-conjugated goat anti-rabbit, and the bromochloroindolyl phosphate-nitroblue tetrazolium reaction. An image cytophotometry system was used to quantitate the percentage of HIV-infected cells. These methods were used to determine the percentage of H9 cells infected with HIV. HIV was detected in 0% of cells on day 1 post infection, 7% on day 4, 41% on day 8, and 5% on day 15. These results paralleled those of the reverse transcriptase assay and an antigen capture ELISA assay for HIV antigen. Thus the AAF modified HIV DNA probe detected HIV nucleic acid in infected H9 cells and the image cytophotometry system improved the sensitivity and objectivity of detection.

Applications of computerized microscopic image analysis in infectious diseases

Advances in computerized microscopy have resulted in image analysis systems that rapidly and precisely measure various aspects of cellular morphology and physiology. These systems-composed of a microscope and attached photomultiplier tube or camera, an image processor, and a computer-have been used to measure lysosomal enzymes, pH, and calcium within phagocytes; to detect viral nucleic acids in in situ hybridization preparations; and to quantitate rates of cellular movement. These experiments have shown that (1) the intracellular proliferation of virulent microorganisms is associated with reductions in acid phosphatase, beta-glucuronidase, and lysozyme activity; (2) virulent Toxoplasma gondii, Legionella pneumophila, and Nocardia asteroides inhibit phagosomal acidification; and (3) changes in intracellular calcium movement affect phagocytic function. These methods have also been used to detect the AIDS virus within cultured lymphocytes and to measure cellular chemotaxis and chemokinesis. Further advances in technology should produce improved microscopic image analysis systems with wider applications for the investigation of infectious diseases.

Comparison of non-radioactive DNA hybridization probes to detect human immunodeficiency virus nucleic acid

Simple and sensitive methods to directly detect the human immunodeficiency virus (HIV) are needed for routine use in the clinical laboratory. In this study, we compared DNA probes prepared by: (1) nick translation with biotinylated dATP; (2) direct covalent biotinylation with photobiotin; (3) direct covalent reaction with 2-acetylaminofluorene (AAF); and (4) a standard radioactive (32P) nick translation procedure. These four DNA probes were hybridized with dilutions of purified target HIV DNA blotted onto nitrocellulose strips. Hybridization was detected using a complex of strepavidin-alkaline phosphatase [for (1) and (2)], alkaline phosphatase-tagged antibodies [for (3)] and by autoradiography [for (4)]. Alkaline phosphatase was detected colorimetrically using nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate. After 1 h, AAF probes were most sensitive (amount detected less than 5 pg), followed by biotin (10 pg), photobiotinylated probes (20 pg) and the radioactive probe (10 pg). The AAF probes were then used to detect HIV DNA in infected CEM cells. We conclude that non-radioactive DNA labelling methods can be used to directly detect HIV DNA under conditions compatible with present clinical laboratory procedures.

Activation and long-term proliferation of human cord blood T cells with human recombinant interleukin-2

We report here the results of in vitro studies that demonstrate that purified human recombinant interleukin-2 (hrIL-2) is a potent stimulant for freshly isolated cord blood lymphocytes of healthy full-term infants. Different culture parameters were studied to define the optimal conditions for eliciting maximal levels of activation. Highest levels of hrIL-2-induced TdR[3H] uptake were recorded on day 7 for cultures containing 100 U hrIL-2/ml. Results of comparative studies demonstrated that the reactivity of cord blood lymphocytes to hrIL-2 was equal to, if not greater than, that of healthy adult lymphocytes. Cord blood cells that had been activated with hrIL-2 could be propagated in long-term (greater than 30 days) cultures as hrIL-2-dependent lines, and these lines could be initiated with a high degree of success. Phenotypic analysis was performed using different monoclonal antibodies and cytofluorometry, and studies characterizing cells of the long-term lines have shown that they consisted of a heterogenous population of T4 helper and T8 cytotoxic/suppressor cells; in some instances, natural killer (NK) cells were also present. Other experiments demonstrated that hrIL-2-activated and hrIL-2-propagated T cells expressed the IL-2 receptor (IL-2R; defined by monoclonal antibody anti-Tac) and the number of IL-2-R-positive cells could be increased two-fold or more by exposing the cells to a phorbol ester. This report provides additional information to support the hypothesis that hrIL-2 not only sustains T cell proliferation (i.e., second signal) but also induces T cell activation (i.e., first signal).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative microscopy: I. A computer-assisted approach to the study of polymorphonuclear leukocyte (PMN) chemotaxis

A computer-assisted approach has been designed to analyze and quantitate polymorphonuclear leukocyte (PMN) chemotaxis. This approach involves a rapid, objective, and semiautomated (user-directed) image-analysis system that is video- and microscope-based. The entire system consists of a microvideo set-up that is put on line with a Digital DEC-LSI-11/73 microcomputer, interfaced with a Datacube analog-digital/digital-analog converter. Video signals of PMN movement are digitized by the system at a resolution of 240 pixels vertically by 320 pixels horizontally (at 256 gray levels) and stored in a 76,800-byte frame buffer. The digitized data are stored for later use or utilized immediately for image segmentation, image display, movement, and morphometric computations for each PMN in a maximum phase field (at 645 X high dry) of 50 PMNs at 10-second intervals. The digitized data are used for computation of cell perimeter, surface area, optical density, contour-ratio, position, speed, and direction of locomotion with the utilization of micro-image-analysis programs written in FORTRAN and MACRO assembly language, with the computer operating under RT-11/TSX+. The reliability, objectivity, and reproducibility of measurements made with this quantitative approach have been tested by comparing with manual-tracing measurements of PMN movement. A correlation factor of 0.99 has been obtained. However, the quantitative-microscopic approach is much faster, more objective, less tedious, and much easier to operate than the conventional manual-tracing method.

A computer-assisted image-analysis system for analyzing polymorphonuclear leukocyte chemotaxis in patients with diabetes mellitus

A computer-assisted image-analysis system that precisely tracks the cell movements of up to 50 polymorphonuclear leukocytes (PMNLs) was developed and used to quantitatively measure cellular chemokinesis and chemotaxis in normal individuals and in diabetic patients with hyperglycemia. The PMNLs were tested in Zigmond chambers with or without a gradient of 10(-7) M n-formylmethionylleucylphenylalanine (f-Met-Leu-Phe). Cellular movement was recorded on videotape by using a videocamera mounted on the microscope. The videotapes were analyzed by computer programs to calculate the speed and direction of each PMNL at 10-sec intervals. Average rates of chemokinesis were 19.6 microns/min without and 25.3 microns/min with f-Met-Leu-Phe. McCutcheon indices, which measure chemotaxis, were 0.01 without and 0.48 with f-Met-Leu-Phe. Similar values were observed in diabetic patients after fasting (average glucose, 217 mg/100 ml) and 2 hr after glucose challenge (average glucose, 309 mg/100 ml). These values demonstrate that PMNLs from diabetic patients with hyperglycemia move at normal rates and respond appropriately to f-Met-Leu-Phe.

Modulation of lysosomal protease-esterase and lysozyme in Kupffer cells and peritoneal macrophages infected with Nocardia asteroides

Virulent Nocardia asteroides reduces lysosomal acid phosphatase activity in murine macrophages. A computer-assisted imaging photometry system was used to quantitate lysozyme and nonspecific esterase-neutral protease levels within individual macrophages following ingestion of nocardiae. In contrast to acid phosphatase, lysozyme and esterase-neutral protease activity was either unchanged or increased following infection by increasing numbers of nocardial cells.

Acidification of phagosomes in murine macrophages: blockage by Nocardia asteroides

Most strains of Nocardia asteroides are susceptible to the detrimental effects of pH 5 when grown in buffered brain-heart infusion broth. Preventing phagosomal acidification may be a mechanism by which this organism survives the microbicidal activity of macrophages. Fluorescein isothiocyanate was conjugated to the surface of Nocardia and Saccharomyces to form pH-sensitive fluorescent probes. The fluorescent emission, and thus the pH, of this probe was quantitated within individual phagosomes by using a computerized cytospectrophotometer. When either live or dead cells of virulent N. asteroides strain GUH-2 were ingested, the phagosomal pH remained above pH 7 for 2 hr. A nonpathogenic soil isolate, N. asteroides strain 19247, only partially blocked acidification. In contrast, when Saccharomyces was used as a control for normal response, the pH decreased to approximately pH 5. Therefore, virulent N. asteroides blocks phagosomal acidification. Because killed Nocardia act in the same manner, this inhibition of acidification appears to be associated with cellular components. This capacity to prevent phagosomal acidification may be prerequisite to the survival of intracellular pathogens.

Effect of human recombinant tumor necrosis factor on the growth of different human and mouse long-term hematopoietic cell lines

Previous studies have demonstrated that one of the most salient features of tumor necrosis factor (TNF) is its ability to induce tumor necrosis in vivo, and the specificity of its cytotoxic/cytostatic activity for tumor cells has been demonstrated in in vitro studies in which this lymphokine has been shown to kill cultured cells of malignant lines and to have no effect on cells of normal diploid lines. Studies described herein defined the effect of highly purified human recombinant TNF on cells of 34 different human and murine hematopoietic cell lines, particularly human leukemic T and B cells of long-term lymphoblastoid cultures. Results of these studies demonstrated that TNF at concentrations of 3,600 U/ml had no significant effect on the growth of these cells as defined by cytotoxicity, measured with the use of the trypan blue dye-exclusion assay and as defined by cytostasis, assayed by the enumeration of cells and the uptake of [3H]-thymidine and -uridine. In contrast, positive control cultures of TNF-sensitive cells from a murine tumor (L-M/clone L-929, connective tissue) displayed at 50% (LD50) reduction in growth by TNF at approximately 5 U/ml. Likewise, human tumors (MCF-7, breast, and HT-29, colon) were also highly sensitive (LD50 less than 100 U/ml). These studies demonstrate that T and B cells of lymphoblastoid lines as well as cells of other hematopoietic lines display little or no sensitivity to TNF.

A quantitative method for the analysis of cell shape and locomotion

A rapid, semiautomated system to quantitate and analyze leukocyte shape and locomotion was developed. Video images of moving leukocytes were obtained using a Vidicon camera mounted on a Nikon phase microscope. The video signal was either inputted directly, or indirectly via a video cassette recorder, to a Datacube video analog-digital, digital-analog converter. A Digital Equipment Corporation LSI 11/23 computer using the RT-11/TSX-Plus operating system and computer programs written in FORTRAN and MARCO assembly language permitted image segmentation, image display, and calculation of position, speed, direction of movement and orientation of each leukocyte at 10 s intervals. These data were stored on a winchester disk for subsequent evaluation of the leukocyte orientation, speed and direction of movement using statistical and graphical methods. The reproducibility of measurements made with the video system was tested by comparison with manual measurements; a correlation coefficient of 0.998 was obtained for the two methods. Rates of chemokinesis were then determined for unstimulated and chemokinetically stimulated polymorphonuclear leukocytes (PMNs) and found to average 12.8 micron/min and 18.1 micron/min, respectively. The high speed, ease of data analysis, and potential for multiparameter evaluation makes this system useful for directly evaluating leukocyte locomotion.

Monocyte function in rhesus monkeys with simian acquired immune deficiency syndrome

Monocyte function in rhesus monkeys with simian acquired immune deficiency syndrome (SAIDS) was compared with that in age-matched normal juvenile rhesus monkeys. The functional tests were 1) chemotaxis, 2) phagocytosis of opsonized Candida albicans, 3) killing and/or growth inhibition of Candida albicans, 4) generation of respiratory burst, and 5) monocyte-derived macrophage response (morphology and/or respiratory burst) to stimulating agents such as lymphokines, gamma interferon, endotoxin, and phorbol myristate acetate. The monkeys tested had either clinical SAIDS (alive with lymphadenopathy, splenomegaly, and lymphopenia or neutropenia) or had terminal SAIDS (moribund due to the disease). Responses of monocytes from 14 monkeys with clinical SAIDS were indistinguishable from those of 9 normal juvenile rhesus monkeys, whereas monocytes from 3 monkeys with terminal SAIDS had enhanced phagocytosis and respiratory burst capacity. Chemotaxis, candidacidal/stasis activity, and response to stimulating agents were normal in these terminal cases. Plasma from the SAIDS monkeys was as capable of opsonizing yeasts and of being able to generate chemotactic factors by endotoxin as was control plasma. SAIDS retrovirus (SRV) was detected by co-cultivation of pure monocyte-derived macrophage cultures with Raji cells, an indicator cell line which forms syncytia in the presence of SRV. Four terminal SAIDS cases and one late-stage clinical SAIDS case were virus-positive when the number of macrophages in the cultures ranged from less than 50 to about 500. Terminal SAIDS monocyte-derived macrophages in culture as long as 17 days produced SRV. These data show that in monkeys with SAIDS the major effector functions of monocytes and macrophages involved in host defense are intact (even up until death). Additionally, some of the monocytes are productively infected, and these infected monocytes are viable and adherent in culture.

Reactivation of tritonated models of human polymorphonuclear leukocytes (PMNs): a computer-assisted analysis

The orientation (chemotaxis) and locomotion (chemokinesis) of human polymorphonuclear leukocytes (PMNs) are generated by an internal movement mechanism that involves active cytoplasmic movement; they are influenced by external environmental and ionic conditions. We have studied the degree to which the orientation and movement mechanisms of PMNs are self-contained within the cell and the degree to which they are under membrane control. PMNs were partially and selectively demembranated by treatment with the non-ionic detergent, octyl-phenoxyl-polyethoxyethanol (commercially known as Triton X-100) under controlled conditions. The tritonated PMNs (referred to in the literature as models) were non-motile and non-locomotory. Addition of ATP/Mg++ with a trace amount of Ca++ to the medium was followed by reactivation of the tritonated PMN models to move again as motile cells. Although these reactivated PMN models actively locomoted, they could no longer orient to chemoattractants. Thus, the reactivation process restored the physical self-contained movement parameters but could not reestablish the orientation capacity (chemotactic responsiveness) that was characteristic of live PMNs. The demembranation process apparently destroyed the chemotactic receptors and/or eradicated the coordination function of the membrane. Videotapes of normal (control) as well as reactivated PMN movement were analyzed for movement characteristics. These characteristics were objectively analyzed with a newly designed computer-assisted micro-image-processing technique whereby the videotapes were digitized and quantified and the actual PMN movement printed out in computer-graphics and tracings (Freeman codes) for confirmation of orientation and movement arising as a result of reactivation.

A charge coupled device-based image cytophotometry system for quantitative histochemistry and cytochemistry

A rapid, semiautomated cytophotometry system for quantitative histochemistry and cytochemistry was constructed. The system consists of a Fairchild charge coupled device (CCD) image camera, a Zeiss Universal microscope, a Datacube analog to digital converter, and a digital Equipment Corporation LSI 11/23 computer operating under RT-11. Computer programs were written in FORTRAN and the MACRO assembly language for the acquisition of data from the CCD device. These data were then used for image segmentation, image display, and calculation of total optical density, perimeter, cell area, and several shape features. The reproducibility of measurement made with the CCD-based cytophotometry system was tested by repeated measurements. The coefficient of variation was estimated to be 1.7% for total optical density and 0.9% for cell area. The CCD-based cytophotometry system was further evaluated by comparing results with measurements made on the same cells with a scanning stage cytophotometer using the HIDACSYS computer programs. Correlation coefficients of 0.96 for total optical density and 0.91 for cell area were obtained between the two systems. We conclude that the high-speed, dimensional stability, small size, and linearity of the CCD-based cytophotometry system will make it useful for quantitative histochemistry and cytochemistry.

Intracellular acid phosphatase content and ability of different macrophage populations to kill Nocardia asteroides

It has been reported that the activity of lysosomal acid phosphatase decreases inversely with numbers of ingested virulent Nocardia spp. in normal murine peritoneal and alveolar macrophages. These studies suggested that this relationship correlated with the effectiveness of these macrophage populations in killing Nocardia asteroides. Experiments were designed to determine if acid phosphatase activity is affected by infection with N. asteroides in four different macrophage populations isolated from normal and nocardia-immunized mice. Macrophages were also tested simultaneously for their ability to kill N. asteroides. Peritoneal, alveolar, and splenic macrophages and Kupffer cells were infected in vitro with strains of N. asteroides of differing virulence. Uptake and killing assays were performed. Acid phosphatase levels and numbers of intracellular nocardiae were quantitated in the same macrophages, using a computer-assisted cytophotometry system. Acid phosphatase activity decreased inversely with numbers of intracellular nocardiae in macrophages that could not kill or inhibit this pathogen. Acid phosphatase activity was not significantly changed in macrophages that inhibited growth of, but did not kill, N. asteroides, whereas activity was increased or enhanced in macrophages that killed most of the ingested nocardiae. The order of nocardicidal effectiveness (and resistance to enzyme activity reduction with infection) for normal macrophages was splenic greater than peritoneal greater than alveolar greater than Kupffer. In contrast, the order of these two parameters for macrophages isolated from immunized mice was Kupffer greater than peritoneal greater than alveolar greater than splenic. These results demonstrate that lysosomal acid phosphatase activity is an effective marker of the ability of macrophages to inhibit growth of and kill N. asteroides and that macrophages isolated from different anatomical sites differ functionally from each other with respect to nocardicidal and acid phosphatase activities.

Comparison of lavaged and intrapulmonary alveolar macrophages in respect to lysozyme content and size in the rat

Lavaged and in situ rat alveolar macrophages were compared with respect to lysozyme content and size in order to assess the extent to which macrophages from pulmonary lavages reflect the in situ cell population. This relationship was studied in normal rats and in rats with pulmonary granulomas induced by glucan stimulation (10 mg/kg given intravenously on Days 5, 3, and 1 before being killed). Alveolar macrophages in pulmonary lavages and histologic sections were stained for lysozyme by the immunoperoxidase method using rabbit antiserum to rat lysozyme. Enzyme content and cell size were measured with a conventional scanning cytospectrophotometer and an automated image analysis system (LEYTAS). Scanning cytospectrophotometry measurements showed that 26% of in situ alveolar macrophages from glucan-treated rats contained more lysozyme than did control cells and that 31% possessed larger areas. Fewer large alveolar macrophages containing increased amounts of lysozyme were detected in lavages of glucan-treated rats. Frequency histograms of lysozyme content and cell size were similar for lavaged and in situ macrophages from control rats. Measurements with LEYTAS confirmed the results. These experiments demonstrate that alveolar macrophages obtained by lavage are representative of their in situ counterparts in normal but not in glucan-treated rats.

Effect of virulent and less virulent strains of Nocardia asteroides on acid-phosphatase activity in alveolar and peritoneal macrophages maintained in vitro

Since virulent strains of Nocardia asteroides grow within macrophages, experiments were designed to determine whether this intracellular pathogen affects lysosomal enzyme levels. Peritoneal and alveolar macrophages from mice were infected in vitro with live or killed N asteroides of the virulent strain GUH-2 or with live nocardiae of the less virulent strain 10905, which is killed by macrophages. The activity of acid phosphatase in individual macrophages was quantitated by means of a computer-assisted cytospectrophotometry system. Slide preparations were Gram stained for quantitation of ingested nocardiae in the same macrophages. The level of acid phosphatase activity in alveolar and peritoneal macrophages was decreased by infection with live cells of the virulent strain; the level of activity was inversely proportional to the number of nocardiae ingested. This effect was not seen with killed bacteria of this strain or with live bacteria of the less virulent strain. These results demonstrate a relation between the virulence of N asteroides strains and the extent of reductions in lysosomal acid-phosphatase activity of macrophages.

Unusual sites of acute osteomyelitis in childhood

In children osteomyelitis is common in the long hours of femur, tibia and humerus. This study reports 16 children, aged 2-13 years, with osteomyelitis at unusual sites: in the bones of the thoracic cage including three involving the clavicle; in the spine, foot and elsewhere. In one case, multifocal involvement of the vertebral body and the knee occurred. In two large series reported previously, the incidence of osteomyelitis was 1-3% in the clavicle, 3-8% in the calcaneus and less than 1% in the ribs. Four out of 16 cases (two involving clavicles, one rib and one with multifocal sites of the lesion) required open biopsies and histological examination to achieve the final diagnosis of osteomyelitis; in three of these patients the causative agent was not identified on culture. Staphylococcus aureus was the infective organism in 50% of cases where cultures were obtained. In five cases there was no growth on culture and specific search for less common organisms, including mycobacteria tuberculosis (AAFB), proved negative. It is suggested that in such situations diagnostic problems may present as the clinical and radiological findings may not be specific or conclusive. In such cases early biopsy is mandatory.

Microphotometric differentiation of human T and B cells tagged with monospecific immunoadsorbent beads

A comparative and statistical study was done of the classification of peripheral blood lymphocytes (PBLs) as T cells, B cells and monocytes by various immunologic procedures and computerized microphotometric analysis. PBLs from 15 healthy male subjects were examined by immunofluorescence, E rosettes, and immunoadsorbent beads (IAB) for T cells and B cells, by phase contrast microscopy and as fixed slide preparations. Cells tagged with IAB for T cells and B cells were fixed, stained with Papanicolaou stain and analyzed. Evaluation of immunologic data shows 50% to 57% T cells, 9.7% to 24.1% B cells, 13.4% to 16.1% monocytes and about 20% unmarked cells. Analysis of T cells shows significant correlations between E and T cell-IAB rosettes, but neither rosetting procedure reveals a positive correlation with immunofluorescence-labelled T cells. Comparison of B cells shows an insignificant correlation between B-cell IAB and immunofluorescence. Results showed that permanent slides of rosetted cells can be made without alteration in relative numbers of rosetted cells. Assessment of immunologically tagged cell samples by image analysis correctly classified 80% to 90% of cells as T and B cells. Evaluation of homogeneity of the T and B cell populations shows the existence of four subsets of B cells and five subsets of T cells.

Reversible arteriopathy following an ergotamine overdose in a heavy smoker

A case of reversible arteriopathy developing in a heavy cigarette smoker taking an overdose of ergotamine is reported. Characteristic radiological changes are illustrated and the aetiology and management of this condition are discussed.