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Biomedical subjects

J M Bernstein

Publications and source records attributed to J M Bernstein.

At least 91 records · Page 5Linked to original sources

Comparative sensitivity of 125I-protein A and enzyme-conjugated antibodies for detection of immunoblotted proteins.

Immunoblotting is a powerful technique for the detection of small amounts of immunologically interesting proteins in unpurified preparations. Iodinated protein A (PA) has been widely used as a second antibody for detection of proteins; however, it does not bind equally well to immunoglobulins from different species nor does it bind to all subclasses of immunoglobulin G (IgG). We compared the sensitivity of [125I]PA with those of both horseradish peroxidase-conjugated second antibodies (HRP) and glucose oxidase-anti-glucose oxidase (GAG) soluble complexes for visualizing bovine serum albumin, human IgG, or human C3 which was either dot blotted or electroblotted to nitrocellulose. [125I]PA was uniformly 10- to 100-fold less sensitive than either HRP or GAG. GAG was more sensitive than HRP except for C3 (electroblotting) and bovine serum albumin and IgG (dot blotting), in which they were equivalent. In general, dot blotting was 10- to 1,000-fold more sensitive than electroblotting. Although relative sensitivities varied depending on the proteins analyzed and the antisera used, GAG appeared to be superior to [125I]PA and HRP for detection of immunoblotted proteins.

Animals↗

Defective immunoregulation in children with chronic otitis media with effusion.

Otitis media and middle ear effusions (MEE) are most common clinical problems in early childhood, for which an estimated one million tympanostomies are performed each year in the United States. Although many factors have been associated with MEE (age, sex, genetics, otitis media, socioeconomic status, feeding style, atopy or hypersensitivity, certain bacteria and viruses), a defective immunoregulatory mechanism in the host may also contribute to the pathogenesis. During the past 2 years, we have evaluated immune function in 90 randomly selected children who underwent repeated tympanostomy for persistent MEE. The T-cell subset ratio (OKT-4/OKT-8) was reduced (below 1.25) in 16%. In 33 children, generation of T-cell growth factor (IL-2) by peripheral blood lymphocytes (PBL) was evaluated and found to be decreased in 11. The mitogenic response of PBL to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) stimulation was abnormal in almost half of the cases. Imbalance of T-cell subsets and decreased production of IL-2 indicate defective immunoregulatory function in some of these children, which may play a role in the pathogenesis of persistent MEE.

Adolescent↗

Immune response to herpes simplex virus in patients with recurrent herpes labialis. II. Relationship between interferon production and cytotoxic responses.

The relationship between the development of cytotoxic cellular immune response to herpes simplex virus type I (HSV-1)-infected autologous cells and the production of interferon (IFN) was studied using in vitro secondary sensitization of peripheral blood leukocytes in subjects with recurrent herpes labialis (RHL) and in normal controls without any history of recurrent herpes labialis. There was a significant discordance between optimal HSV-1 antigen dose required for induction of peak cytotoxic responses and for maximal activity of IFN. Moderate IFN activity (6-100 U/ml) was demonstrated in all HSV-1 antigen-stimulated peripheral blood leukocytes collected from subjects during both acute and convalescent phase of RHL. However, only 50% of seropositive controls and no seronegative controls exhibited detectable IFN activity, when stimulated with HSV-1 antigen, although such in vitro stimulation resulted in maximal virus-specific cell-mediated cytotoxicity. A correlation of virus specific cytotoxic activity to HSV-1 and IFN production (r = 0.38, p less than 0.05) was less marked than that of cytotoxic activity to K562 (natural killer-sensitive target cells) and IFN titer (r = 0.48, p less than 0.01). Furthermore significant reverse correlations between cytotoxicity against HSV-1-infected autologous cells and a titer of gamma-IFN was observed in samples with high cytotoxic activity. These observations suggest that gamma-IFN produced by HSV immune T cell may also act as an autoregulatory factor against the production of cytotoxic cellular activity against HSV-1-infected autologous cells.

Adult↗

Immune responses to herpes simplex virus in patients with recurrent herpes labialis: I. Development of cell-mediated cytotoxic responses.

Groups of subjects during acute (0-3 days) and convalescent (2-3 weeks) phase of recurrent herpes labialis (RHL), and other subjects seropositive or seronegative for herpes simplex virus type 1 (HSV-1) antibody without any history of RHL, were tested for the appearance of cell-mediated cytotoxic responses by stimulating peripheral blood leukocytes (PBL) in vitro with ultraviolet-inactivated HSV-1 antigen, using the release of radiolabelled chromium (51Cr) from HSV-1-infected autologous, or allogeneic lymphocytes and K562 erythroleukemia cell line as nonspecific targets. Development of HSV specific cytotoxic response using autologous targets was essentially limited to subjects with RHL and in HSV antibody seropositive control subjects. Peak activity was observed during the acute phase of the disease, compared to the activity in the convalescent phase in seropositive subjects with RHL, and was preceded by high lymphoproliferative response to HSV. Higher cytotoxic responses against K562 cells were also observed in RHL subjects compared to the controls. Depletion of Leu-2+, Leu-3+ or Leu-11 effector lymphocytes from HSV-1-stimulated PBL cultures by treatment with complement and appropriate monoclonal antibodies resulted in significant reduction of cytotoxicity to HSV-1-infected autologous cells. However, cytotoxicity to K562 cells was reduced only after depletion of Leu-11+ cells. Low levels of allogeneic restriction were observed for cytotoxicity to HSV-1-infected targets. These observations suggest selective activation of virus specific Leu-2+ and Leu-3+ T cell subsets as well as natural killer cell mediated cytotoxic mechanisms during the active phase of recurrences of herpes simplex virus infection.

Adolescent↗

The effect of biliary obstruction on a gram-negative bacteremic challenge: a preliminary report.

Alterations in the sequestration and destruction of bacteria were studied after 10 days of biliary obstruction. Intraperitoneal injection of radiolabeled Escherichia coli was used to study bacterial localization in rats 10 days after common duct ligation and transection or sham celiotomy. Animals were sacrificed 4 hours later and uptake by liver, spleen, lung, and kidney were studied with a scintillation counter. No significant difference in localization between the two groups was noted. Bacteremia was induced in a second set of animals and quantitative bacterial organ cultures were performed. Significantly more viable organisms were identified in lung, liver, and kidney of animals that underwent common duct ligation and transection, when compared with controls that underwent sham celiotomy. This suggests that there is a defect in bacterial killing after 10 days of biliary obstruction. The inability to effectively clear and kill gram-negative bacteria in patients with biliary obstruction may account for some of the clinical complications seen in this patient population.

Animals↗

Relative efficacy and toxicity of netilmicin and tobramycin in oncology patients.

We prospectively compared the efficacy and safety of netilmicin sulfate or tobramycin sulfate in conjunction with piperacillin sodium in 118 immunocompromised patients with presumed severe infections. The two treatment regimens were equally efficacious. Nephrotoxicity occurred in a similar proportion in patients treated with netilmicin and tobramycin (17% vs 11%). Ototoxicity occurred in four (9.5%) of 42 netilmicin and piperacillin and in 12 (22%) of 54 tobramycin and piperacillin-treated patients. Of those evaluated with posttherapy audiograms, three of four netilmicin and piperacillin-treated patients had auditory thresholds return to baseline compared with one of nine tobramycin and piperacillin-treated patients. The number of greater than or equal to 15-dB increases in auditory threshold as a proportion of total greater than or equal to 15-dB changes (increases and decreases) was significantly lower in netilmicin and piperacillin- vs tobramycin and piperacillin-treated patients (18 of 78 vs 67 of 115). We conclude that aminoglycoside-associated ototoxicity was less severe and more often reversible with netilmicin than with tobramycin.

Adult↗

Fatal coxsackievirus B4 infection in a neonate.

We reported a fatal coxsackievirus B4 infection in a neonate. The CSF WBC was elevated, with polymorphonuclear leukocytes predominating initially and lymphocytes predominating later in the illness. Autopsy findings included inflammation of the heart and liver. Coxsackievirus B4 was isolated from the heart and quantitated as 10(3) 50% tissue culture infectious doses (TCID50) per gram of myocardium.

Coxsackievirus Infections↗

Further observations on the role of IgE-mediated hypersensitivity in recurrent otitis media with effusion.

One hundred young patients with recurrent otitis media with effusion (OME) were evaluated for IgE-mediated hypersensitivity by critical analysis of history, physical findings, skin testing for selected antigen, laboratory determination of total IgE, and radioallergosorbent testing (RAST) for six inhalant and two food allergens. The patients could be divided into allergic rhinitis and nonallergic groups. Allergic rhinitis patients had higher total IgE in their serum, and middle ear effusion (MEE). IgE was elevated in 16 of 35 allergic patients. In 8 of these 16 (23% of the allergic group), the IgE/mg protein was higher in the MEE than in the corresponding serum, suggesting local production of IgE. Nasal IgE was substantially increased in the allergic patients; however, in many patients there was no correlation between the corresponding MEE IgE and elevated nasal IgE, suggesting that local production of nasal and middle ear IgE is independent. We conclude that IgE-mediated allergic reactions may play a role in the pathogenesis of OME in about 23% of young allergic patients.

Adolescent↗

Recent advances in otitis media with effusion.

OME is similar to other chronic inflammatory diseases with the additional fact that ventilation of the middle ear is an extremely important and necessary part of therapy. Antimicrobial therapy alone may not cure middle ear inflammatory disease as long as Eustachian tube dysfunction persists. If Eustachian tube dysfunction and middle ear fluid persists, all forms of immunologic reactivity may occur in the middle ear which may result in persistent effusion and damage to the mucosal system, to the middle ear ossicles, and to the mastoid mucosal system. These changes may require more aggressive surgical management. It is obvious that we must learn more about the physiology and pathophysiology of the Eustachian tube; about understanding of the systemic, and particularly the local humoral and cell-mediated immune response in the middle ear. Finally, we must determine the potential role of inflammatory mediators, both in the protection against disease and also in the potential role that they play in tissue injury. Encouraging progress is being made in all of these areas and it seems likely that the increased research interest and productivity from laboratories throughout the world will eventually lead to the goal of enhanced prevention and improved treatment of OME.

Child, Preschool↗

Infectivity of vascular sutures.

Bacterial adherence to vascular sutures was evaluated in vitro using radioactively labeled Staphylococcus aureus. The following suture materials were tested: polypropylene, silicone-treated braided polyester, and Teflon-treated braided polyester. Significantly fewer bacteria adhered to the monofilament polypropylene than either of the braided polyester sutures. There was no significant difference between silicone-treated and Teflon-treated polyester from the standpoint of bacterial adherence. Vascular sutures were evaluated in vivo using a mouse wound model. Sutures were tested with and without knots. When tested without knots, fewer bacteria were recovered from wounds containing polypropylene suture compared to either of the braided materials, although this apparent advantage did not prove to be statistically significant. When studied with knots, the differences among types of suture were much less marked and, again, not significant. The purported contribution of the monofilament structure of a suture to its infection resistance may have been overstated.

Adhesiveness↗

Mucosal cell-mediated immunity to varicella zoster virus: role in protection against disease.

By indirect immunofluorescence, enzyme-linked immunosorbent assay, and in vitro lymphocyte proliferation, we studied the antibody and cell-mediated immune response to varicella zoster virus (VZV) in serum, peripheral blood lymphocytes, and tonsillar lymphocytes in 49 children before and after tonsillectomy and adenoidectomy. Among the naturally infected patients seropositive for VZV antibody, most demonstrated VZV-specific proliferation in the peripheral blood and tonsillar lymphocytes, with activity consistently higher in the tonsillar lymphocytes. Several patients seronegative for VZV antibody and without a prior history of clinical chickenpox also manifested VZV-specific proliferation in the tonsillar lymphocytes, and less frequently in peripheral blood lymphocytes. Of these, six children with high levels of activity in tonsillar lymphocytes, with or without high levels in the peripheral blood lymphocytes, failed to develop disease after intimate exposure to VZV in family settings. On the other hand, three other subjects with little or no VZV-specific proliferative activity in the tonsillar lymphocytes developed disease after similar exposure to VZV. These observations suggest the development of VZV-specific mucosal cellular immunity after overt or inapparent exposure to VZV. The appearance of such immunity appears to have a protective role against reinfection even in the absence of detectable serum antibody.

Adolescent↗

Observations on immune mechanisms in otitis media with effusion.

In this brief review of recent advances in immunological reactivity in otitis media, I have neither attempted to review the field from a historical perspective, nor attempted a critical analysis of the current status and future frontiers of this area. I have, rather, reviewed 5 areas that are being pursued in our laboratory and compare our investigations with those being performed throughout the country and abroad. It is my sincere hope that investigations into these areas will continue and will lead to potentially fruitful and meaningful data that will eventually unravel the mystery of persistent OME.

Antigen-Antibody Complex↗

Characteristics of lymphocyte and macrophage reactivity in otitis media with effusion.

On the basis of our observations and previously published data, it is proposed that in at least certain forms of chronic otitis media with effusion there is a relative predominance of macrophage--monocyte cells which are actively immunosuppressive for the proliferative response to mitogens and specific antigens, as well as for the synthesis of specific immunoglobulins. Such immunological hypo-responsiveness may be related to the pathogenesis of chronic otitis media with such effusions.

Adenoids↗

Immunologic aspects of otitis media with effusion. II. Nature of cell-mediated immunosuppressive activity in middle ear fluid.

The effects of middle ear effusions from patients with serous, seromucoid, mucoid, and purulent forms of otitis media with effusion on lymphoproliferative responses and polyclonal immunoglobulin synthesis were determined in peripheral blood and adenoidal lymphocytes. The responses were studied after stimulation of lymphocytes by phytohemagglutinin, pokeweed mitogen, purified protein derivative, herpes simplex virus, sheep red blood cells, or ovalbumin. Serous and seromucoid middle ear effusions resulted in significant suppression of proliferative responses to phytohemagglutinin, purified protein derivative, and herpes simplex virus and of polyclonal immunoglobulin synthesis in response to pokeweed mitogen, sheep red blood cells, and ovalbumin. The suppressive activity appeared to be associated with low-molecular-weight soluble products liberated by esterase-positive adherent population of cells in middle ear fluid.

Adenoids↗