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Biomedical subjects

H M Shapiro

Publications and source records attributed to H M Shapiro.

At least 91 records · Page 5Linked to original sources
PubMed1984

Decreased expression of human class II antigens on monocytes from patients with acquired immune deficiency syndrome. Increased expression with interferon-gamma.

The expression of HLA-DR (a class II histocompatibility antigen) on monocytes isolated from the peripheral blood of normal individuals and patients with acquired immune deficiency syndrome (AIDS) was investigated by the use of dual fluorescent staining and cytofluorometry. In animal models the absence of class II positive monocytes is linked to a failure of T cells to respond to antigens. We now report that patients with AIDS have a paucity of HLA-DR+ monocytes. The percentage of HLA-DR+ monocytes among eight normal individuals ranged from 49.3 to 95.0%+, and only one individual had less than 50% HLA-DR+ monocytes. HLA-DR expression on monocytes from homosexual male patients with lymphadenopathy was similar to that of normal subjects (range, 58.0 to 97.4%+). In contrast, seven of nine patients with AIDS had less than 50% HLA-DR+ monocytes (range, 13.4 to 78.8%+). The in vitro incubation of monocytes from AIDS patients with cloned human interferon-gamma resulted in an increase of the expression of HLA-DR to near normal levels.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Accessory cell requirement for activation antigen expression and cell cycle progression by human T lymphocytes.

Stringent accessory cell (AC) depletion by a three-step procedure--plastic adherence, nylon wool adherence, followed by simultaneous treatment with two anti-AC monoclonal antibodies + complement--has allowed the demonstration of several AC-dependent stages in the T cell activation pathway. Simultaneous analysis of DNA content and cell surface immunofluorescence (correlation of activation antigen expression with cell cycle position) or DNA and RNA content (cell cycle position) of cultured cells was accomplished by dual parameter flow cytometry. AC-depleted, PHA-stimulated human peripheral blood T lymphocytes (PBTL) failed to exhibit "early" indicators of activation, including increased RNA content, expression of three activation-associated cell surface proteins (IL 2 receptor, transferrin receptor, and 4F2 protein), and the production of IL 2. The AC-depleted PBTL that failed to express these "early" markers of activation also failed to progress into the "late" phase of activation, DNA synthesis. All indicators of PHA responsiveness were fully replenished upon addition of AC but were only reconstituted to intermediate levels by addition of excess quantities of either highly purified IL 1 or crude AC-conditioned medium with lymphocyte-activating factor activity. These data suggest that the AC membrane plays a key and as yet undefined role in the stimulation of T cells by PHA.

Antigen-Presenting Cells↗
PubMed1984

Dual parameter flow cytometric analysis of DNA content, activation antigen expression, and T cell subset proliferation in the human mixed lymphocyte reaction.

This study provides direct correlation via dual parameter flow cytometry (simultaneous assessment of immunofluorescence and DNA content) between mixed lymphocyte reaction (MLR) responder cell entry into the S/G2/M phases of the cell cycle with the kinetics of expression of two activation-associated cell surface proteins, Tac (IL 2 receptor) and 4F2 (unknown metabolic function). A small population of activated cells was identifiable by expression of both Tac and 4F2 antigens before peak DNA synthesis in the MLR. This population of activation antigen-positive cells expanded linearly in size from days 3 to 7 of culture. Treatment of immature MLR cultures with anti-4F2 Mab and complement (C) before DNA synthesis (treatment on day 3, peak DNA synthesis on days 5 to 6) resulted in blunted proliferation and activation antigen expression when the same culture was analyzed after maturation on day 6, indicating that the activated population had been previously detected and removed by anti-4F2 Mab + C. The 4F2 antigen was expressed on a greater percentage of cells in the MLR at all times (days 3 to 9) than was Tac, was present on virtually all S/G2/M phase responder cells, and a large fraction of cells remained intensely 4F2+ subsequent to peak DNA synthesis. In contrast, after initially preceding responder cell entry into the S phase of the cell cycle, the kinetics of Tac antigen expression closely paralleled the kinetics of responder cell proliferation. A subpopulation of cycling responder cells was noted in all MLR cultures studied that expressed Tac antigen weakly or not at all. Cells within both T4 and T8 cell subsets proliferate with similar kinetics in response to alloantigen. The possibility that activation antigens can be utilized to study effector cell generation in the MLR and that this flow cytometric technique may be utilized to analyze the response to various alloantigens is discussed.

Antigens, Surface↗
PubMed1983

Minimal alveolar concentrations for halothane, enflurane, and isoflurane in the cat.

The minimal alveolar concentrations for halothane, enflurane, and isoflurane in the domestic cat were found to be 1.19 +/- 0.05 (SEM)%, 2.37 +/- 0.06%, and 1.61 +/- 0.04%, respectively. During the potency studies, it was observed that enflurane and isoflurane resulted in shorter wake-up times, compared with halothane. However, enflurane and isoflurane produced electroencephalographic (EEG) and clinical signs of CNS irritability (EEG spiking, myoclonus) in normocapnic or mildly hypocapnic cats. In addition, enflurane and isoflurane caused greater airway irritability (coughing, salivation) than did halothane.

Anesthesia, Inhalation↗
PubMed1983

Simultaneous flow cytometric analysis of human T cell activation antigen expression and DNA content.

Cell-surface antigens that are induced to appear on T cells activated by the lectin phytohemagglutinin-P (PHA) can be classified both on the basis of the kinetics of their appearance and on their growth-association properties. Seven distinct T cell activation antigens, defined by monoclonal antibodies, were classified as early, intermediate, or late antigens based on their temporal appearance relative to DNA synthesis. Four antigens, the transferrin receptor, the T cell activation antigen Tac, the 4F2 antigen, and the 49.9 antigen were early antigens, whereas the OKT10 antigen appeared at intermediate times and both HLA-DR and antigen 19.2 appeared late. The use of a dye, Hoechst 33342, which stains DNA stoichiometrically, allowed the simultaneous analysis of immunofluorescence and cell cycle position of individual cells. This analysis unexpectedly revealed that essentially all cells in the proliferative phase of the cell cycle expressed each of the four early-activation antigens. The correlation between expression of the four early-activation antigens and T cell proliferation suggests that these molecules are important for the growth of all T cells. The relationship of two of these activation antigens, known to be the receptors for transferrin and interleukin 2, a T cell growth factor, is discussed with special reference to the roles of their ligands in supporting the growth of T cells.

Antibodies, Monoclonal↗
PubMed1983

Multistation multiparameter flow cytometry: a critical review and rationale.

The capacity for fluorescence excitation by beams of different wavelengths at separate points along the sample stream, and the capacity for computer analysis of multiparameter data thus obtained, are now available in flow cytometer/sorter systems from commercial producers. It is now readily apparent to most experienced users of flow cytometers that such multiparameter analysis offers the most convenient solution to the problem of characterizing subpopulations of cells within a mixed population. The use of multiple beams facilitates resolution of fluorescence signals from several probes within or upon a single cell and widens the range of analytical alternatives available to experimenters. This critical review discusses the history of the instrumentation, the parameters now measurable and the probes used for their measurement, and the methods for data analysis. Required sensitivity and precision are discussed, leading to the conclusion that many of the advantages of multistation, multiparameter flow cytometry can be made available in less complex and less costly instruments using less powerful sources and less elaborate computer hardware than are presently incorporated in commercial apparatus.

Antigens, Surface↗
PubMed1983

Immunofluorescence measurement in a flow cytometer using low-power helium-neon laser excitation.

Helium-neon lasers are economical and efficient light sources; their utility in flow cytometry to date has been limited by the lack of fluorescent probes that can be excited at 633 nm. Allophycocyanin (APC), a highly fluorescent phycobiliprotein, can be used as an antibody label and has spectral characteristics suitable for use with He-Ne lasers; we undertook to resolve whether a low-power (7 mW) He-Ne laser could provide sufficient excitation to permit flow cytometric detection of APC-labeled antibodies on cell surfaces. We made an APC conjugate of monoclonal antibody 4F2, which reacts with an antigen abundant on the surfaces of activated human T-lymphocytes; APC-4F2 was used to stain blood mononuclear cells that had been cultured with and without phytohemagglutinin (PHA). Cells so stained were examined in a flow cytometer with orthogonal illumination at 633 nm from a 7 mW He-Ne laser; antibody-bearing cells were detectable by fluorescence emission above 665 nm. Cells from the same cultures were stained with fluorescein-labeled 4F2 antibody and examined in a flow cytometer with argon ion laser excitation at 488 nm. Percentages of antibody-bearing cells determined from APC fluorescence and from fluorescein fluorescence were in good agreement. It thus appears that He-Ne lasers and APC-antibodies are usable for immunofluorescence measurements; the sensitivity attainable with this technique remains to be determined.

Animals↗
PubMed1983

Cell membrane potential changes follow Epstein-Barr virus binding.

Upon binding to receptor-bearing target cells, viruses cause cell membrane potential changes. Epstein-Barr Virus causes a biphasic membrane potential change in receptor-bearing B lymphocytes but not receptor-negative T lymphocytes, as measured by flow cytometry or cyanine dye uptake. Membrane potential changes from EBV binding to receptor-bearing cells resemble electrical responses of other cells following ligand binding to transmembrane receptors.

Cells, Cultured↗
PubMed1983

Cerebral blood flow during high frequency ventilation in cats.

Cerebral blood flow (CBF) was compared during conventional low frequency ventilation (LFV) [tidal volume 15 ml/kg, respiratory rate 12] and high frequency ventilation (HFV) [tidal volume 3 ml/kg, respiratory rate 100] in normal cats. The intra-arterial 133Xenon technique was used to determine CBF. No significant difference in CBF was present between the 2 groups. The mean CBF was 46.6 +/- 14.2 ml/dl X min during LFV and 44.4 +/- 12.2 ml/dl X min during HFV. Additionally, mean arterial pressure, CVP, intracranial pressure (ICP), cerebral perfusion and airway pressures were not significantly different between the groups. HFV has little effect on cerebral hemodynamics.

Animals↗
PubMed1982

Monitoring the effect of anti-cancer drugs on L1210 cells by a mitochondrial probe, rhodamine-123.

The cancer chemotherapeutic agents 1-beta-D-arabinofuranosylcytosine (Ara-C), methotrexate, and 5-fluorouracil cause a rapid loss of mitochondrial Rh-123 uptake in L1210 cells, which correlates with the loss of clonogenic ability. The loss of Rh-123 uptake is irreversible and occurs prior to Trypan Blue staining. Thus, the antimetabolites, unlike freeze-thawing and detergent treatments, generally cause mitochondrial damage prior to changes in plasma membrane permeability. Since the effect of antimetabolites on Rh-123 uptake is maximal at 24 h, the Rh-123 assay may provide a rapid alternative to the clonogenic assay for monitoring the cytotoxic effects of these drugs. Our results also suggest that the inhibition or impairment of mitochondrial function may be an important step in the cytocidal and/or cytostatic action of anti-cancer drugs.

Animals↗
PubMed1982

Intracranial hypertension and brain oedema in albino rabbits. Part 3: Effect of acute simultaneous diuretic and barbiturate therapy.

Increased intracranial pressure due to brain oedema was produced in albino rabbits by combining a cryogenic lesion in the left hemisphere with the intraperitoneal administration of 6-aminonicotinamide (cytotoxic agent). The following parameters were assessed: intracranial pressure (ICP), systolic arterial pressure (SAP), central venous pressure (CVP), EEG, brain water and electrolyte content, gross pathology, and blood brain barrier integrity. Acute therapy to reduce ICP was performed by administering a bolus of mannitol (1 gm/kg) and 30 minutes later, also in bolus, frusemide (5 mg/kg). Immediately following the administration of mannitol an infusion of pentobarbitone was commenced; this was continued for one hour so that a total of 10 mg/kg was administered. There was a 50% reduction of ICP at one hour from initiation of treatment. The brains of the animals were extracted immediately upon cessation of therapy (pentobarbitone) and they revealed a significant reduction of water content for the right, uninjured, hemisphere only, when compared to controls; a slight but not significant reduction of the brain sodium and potassium was noted in both hemispheres. There was no change noted in the gross pathology and extent of blood brain barrier breakdown. In all animals epinephrine infusion had to be administered for between 20 and 30 minutes to maintain a SAP over 80 torr. There seems to be no advantage in the simultaneous administration of barbiturates and diuretics for the control of ICP due to brain oedema.

Animals↗
PubMed1982

The neurologic effects of thiopental therapy following experimental cardiac arrest in cats.

To define the utility of high-dose barbiturate therapy following an episode of complete global cerebral ischemia, we investigate the effects of 60 mg/kg of thiopental given to cats five minutes after resuscitation from 12, 14, or 16 min of electrically induced ventricular fibrillation (VF). All aspects of the arrest, resuscitation, with post-arrest care were carefully controlled, with the EEG becoming isoelectric 20-25 s after the onset mean resuscitation time of 2.5 +/- 0.2 (SEM) min. For any given duration of VF, there were no differences (control vs thiopental) in any pre- or post-arrest parameters (blood pressure, blood gases, electrolytes, etc.) A total of 68 resuscitated cats were entered into various treatment and control groups, and all but one group received 20-24 h of post-resuscitation paralysis, mechanical ventilation, and ICU support before being extubated. Cats received an additional six days of aggressive nursing care, and daily examinations were performed with the assignment of a neurologic deficit score (NDS) between 0 (normal) and (brain dead). Autopsies were performed to determine the cause of death in animals which died before the end of the seven-day observation period. The early post-arrest period was marked by the occurrence of repetitive, rhythmic bursts of high-frequency electroencephalographic (EEG) activity (? seizures) in 38 per cent of control animals (16/42, all arrest times combined). Ten of these animals died as a result of severe neurologic injuries. By contrast, only 12 per cent of treated cats (3/26) developed similar EEG patterns (P less than 0.05) and there were no neurologic deaths in the thiopental groups. The differences in the incidence of neurologic deaths (control vs. thiopental) was significant (P less than 0.02). The change in overall mortality did not quite reach significance (36 per cent vs. 21 per cent), and treatment had no effect on the incidence of deaths due to cardiovascular causes (e.g., myocardial infarctions). In spite of the effects on mortality, treatment had no effect on the neurologic function of survivors (assessed by NDS). These findings suggest that thiopental improved survival rates by suppressing an unusual post-arrest EEG pattern (? anticonvulsant effect), but had no additional cerebral protective effects.

Animals↗