Biomedical subjects
Publications and source records attributed to R Goldstein.
A simple, readily available, inexpensive device is presented that makes research of topically applied vasoactive drugs more accurate and reproducible. It is possible to recollect the drug or wash it away from the vessel. Reversal drugs can also be used in the immediate vicinity of the vessel wall.
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An achromatic surface in a complex scene has both an apparent reflectance attribute (lightness) and an overall intensitive attribute (brightness). We studied changes of these two attributes as a function of changes in illumination level and pattern complexity. Subjects observed simultaneously two arrays of simulated achromatic surfaces with identical reflectance distributions. The left-hand array (standard) was always illuminated at a moderate level. The right-hand array (test) had different illuminances from trial to trial. The subjects adjusted patches in the test array to match the corresponding patches in the standard array in either lightness or brightness. In complex patterns (32 grays) lightness constancy was nearly perfect; test reflectance settings were invariant over illuminance. In disk/annulus patterns (two grays), the lightness-match data confirmed previously published reports. At high illuminances, the standard patches could be matched with a smaller range of test-array reflectances than at low illuminances, i.e., lightness constancy was imperfect. Brightness matches varied substantially as a function of illuminance in all conditions.
Right atrial hypertension has been considered to have a major physiologic influence on the formation of transudative pleural effusions. Since pleural fluid is thought to be cleared primarily by the parietal pleural lymphatic vessels that empty into the systemic veins, systemic venous hypertension secondary to right atrial hypertension should decrease the lymphatic drainage of the pleural space. We retrospectively studied nine patients and prospectively studied 18 patients with long-term right atrial or pulmonary arterial hypertension (or both). All patients had stable respiratory symptoms, and none had a significantly elevated pulmonary arterial wedge pressure. Our purpose was to determine the relationship of right atrial and pulmonary arterial hypertension to the development of transudative pleural effusions. Posteroanterior and bilateral decubitus chest roentgenograms and ultrasound were used to detect pleural effusions. Pleural effusions were not identified in any of the 27 patients, even in four patients with right atrial pressures greater than 20 mm Hg. We conclude that chronic elevation of right atrial pressure or pulmonary arterial pressure (or both) alone is not a cause of pleural effusion. In contrast, elevation of left atrial and pulmonary arterial wedge pressures is associated with the formation of transudative pleural effusions in man. Thus, if pleural effusions are detected in patients who have cor pulmonale, a search should be made for coexisting left heart failure or a primary cause of pleural inflammation, such as pulmonary emboli or infection.
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Staphylococcus aureus Cowan I (SAC) is a potent stimulus of B cell proliferation and differentiation, the latter being T cell-dependent. It has been suggested that immunoglobulin and IgM rheumatoid factor (RF) production in response to SAC involves radiosensitive T helper cells. We studied normal peripheral blood mononuclear cell (PBMC) cultures to assess the roles of radiosensitive T cells and Leu-2 positive suppressor cells in the cellular control of SAC-stimulated IgM and IgM RF responses. Depletion of Leu-2 positive T cells from reconstituted autologous PBMC cultures resulted in an increase in SAC-stimulated IgM production in the majority of individuals, implying the involvement of Leu-2 positive suppressor T cells in this system. Suppression by Leu-2 positive cells is less evident in the SAC-induced IgM RF response, suggesting qualitative differences between IgM and IgM RF SAC-stimulated responses in PBMC cultures from the same normal individuals. Irradiation (1000 rads) of the T cell-enriched subpopulation, either with or without Leu-2 positive cell depletion, resulted in statistically significant decreases in IgM and IgM RF production in response to SAC in reconstituted autologous cultures, providing further evidence of a Leu-2 negative radiosensitive sheep-cell rosetting cell active in in vitro SAC responses. In contrast, PWM-stimulated PBMC cultures showed almost exclusively increases in total IgM and IgM RF production when T cells were irradiated (1000 rads) before culture, consistent with the radiosensitive T suppressor cell involved in the in vitro immunoglobulin responses to PWM. The same five out of nine individuals produced IgM RF, under different culture conditions, in response to PWM and SAC, suggesting that the ability of an individual to produce IgM RF lies intrinsically within the B cell.
This article reviews the current knowledge of genetic factors conferring susceptibility to several major rheumatic disorders, in particular, rheumatoid arthritis (RA), juvenile chronic arthritis (JCA), systemic lupus erythematosus (SLE), and Sjögren's syndrome. Emphasis is given to major histocompatibility complex associations with these diseases, particularly rapidly evolving knowledge of class II HLA genes and disease-conferring "epitopes." Non-MHC-linked genes, such as T cell receptor and immunoglobulin genes, also may be involved.
The object of this study was to ascertain the frequency of postinfectious cow's milk protein hypersensitivity (CMPH). Twenty-four infants less than 3 months old were included in the study. Following hospitalization for acute gastroenteritis, the infants were given a protein hydrolysate formula for a period of 6 weeks, after which an intestinal biopsy was performed. Thereafter, a milk challenge was given. The existence of CMPH was defined as a postchallenge reduction of one or more of the mucosal disaccharidases below the normal levels for our laboratory. A bacterial etiology of the gastroenteritis was found in 10. Nineteen infants had no adverse reaction to cow's milk after 6 weeks on a hypoallergenic formula. Only two could be confidently diagnosed as having developed secondary CMPH; both had been infected by Escherichia coli 0 111. One infant had primary CMPH and one extra-intestinal CMPH. The incidence of secondary CMPH with gastrointestinal manifestations in this series was considerably less than described elsewhere.
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Phasmid (phage-plasmid) P4 is capable of propagating as a temperate phage, lytic helper-dependent phage, and as a plasmid (pP4vir1). Alteration of cellular growth conditions can be used to manipulate the copy number (n) of pP4vir1 from low (n = 1-2) to high (n = 30-40). The levels of gene expression of P4 in the plasmid and phage states are radically different. While there is high expression of P4 proteins in the phage state, low levels of gene expression are found in the plasmid mode of propagation thereby allowing pP4vir1 to remain intracellularly without perturbing host homeostasis. Possible evolutionary origins of phasmid P4 are discussed.
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A patient with longstanding Mollaret's meningitis had an increased number of circulating natural killer cells during an acute attack, as evidenced by 73% large granular lymphocytes and 80% Leu-11a-positive peripheral mononuclear cells. Numbers of large granular lymphocytes and Leu-11a-positive cells returned to normal by three months after the attack. Similarity of the morphological features of the Mollaret's cell to those of large granular lymphocytes is noted.
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Peripheral blood mononuclear cells from 20 healthy adults were tested in vitro for the production of IgM rheumatoid factor (RF) in response to Staphylococcus aureus Cowan I (SAC) or pokeweed mitogen. Fifteen of the 20 normal subjects produced greater than or equal to 4 ng/ml IgM-RF (mean +/- SD 46 +/- 55 ng/ml) in response to SAC, compared with only 2 of 20 who produced greater than or equal to 4 ng/ml IgM-RF (mean +/- SD 2 +/- 4 ng/ml) in response to pokeweed mitogen (P = 0.0001). Separation and reconstitution of autologous T and B cell-enriched fractions, with and without prior T cell irradiation, provided evidence for a radiosensitive T helper/inducer cell involved in the IgM-RF response to SAC in 70% of the normal subjects studied. SAC appears to be a potent stimulus of IgM-RF production, with a cellular mechanism distinct from that of other in vitro systems.
A 10-month-old infant is described who suffered from extensive atopic dermatitis, failure to thrive, hypoalbuminaemia and oedema. Large amounts of sticky exudate were lost through the skin and were shown to be rich in albumin. As renal and intestinal loss of protein was excluded, the patient's condition was ascribed to the loss of albumin through the skin at a rate that out-stripped the synthesis of this protein. Treatment with steroids resulted in dramatic clearing of his dermatitis, and subsequent rapid correction of his hypoalbuminaemia, oedema and anaemia.
The present investigation was conducted to assess the behavioral and electrophysiological impairments exhibited by adult male rats as a function of the developmental stage during which lead exposure occurred. Dams were given either a lead acetate (0.3%) or a control drinking solution during days 16-23 of gestation, days 1-8 or days 9-16 of nursing. The temporal and spatial activity patterns exhibited by gestationally exposed offspring in the open field between 42-45 days of age was distinguished from all other groups by the absence of a decrement in peripheral field activity across days and by increased exploration of the center field. Although open field activity proved sensitive to the timing of lead exposure, power spectral analyses of hippocampal and cortical EEG activity at 70-72 days of age revealed that lead selectively depressed 6-7 Hz energy in the hippocampus, independent of the developmental stage of exposure; cortical EEG and other hippocampal theta frequencies were unaffected. The differential sensitivity of open field activity and select hippocampal theta frequencies to the timing of lead administration suggests that the identification of toxic consequences depends on the function assessed and the developmental stage during which lead exposure occurred.