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Biomedical subjects

R Hardy

Publications and source records attributed to R Hardy.

At least 109 records · Page 6Linked to original sources
PubMed1981

Characterization of a human B cell-specific antigen (B2) distinct from B1.

A human B lymphocyte-specific antigen (B2) was identified and characterized by the use of a monoclonal antibody. By indirect immunofluorescence and quantitative absorption, B2 was shown to be expressed exclusively on Ig+ B cells isolated from peripheral blood and lymphoid tissues. In contrast, B2 was not found on monocytes, resting and activated T cells, Null cells, or granulocytes, nor was it found on cell lines or tumor cells of T cell or myeloid origin. Functional studies demonstrated that only B2 antigen-positive splenocytes could be induced to differentiate into plasma cells under the stimulus of pokeweed mitogen, further confirming the B cell specificity of B2. It was then demonstrated that the B2 antigen was distinct from the previously described B cell-surface determinants including surface immunoglobulin, Ia-like antigens, and Fc and C3 receptors. More importantly, the B2 antigen has been clearly shown to be distinct from the previously described B cell-specific antigen, B1, by its m.w. and expression on normal and malignant B lymphocytes. The distinct distribution of B2 on normal and malignant lymphocytes supports the notion of B cell heterogeneity and provides further evidence for existence of subpopulations of human B lymphocytes.

Absorption↗
PubMed1980

Ewing's tumor metastatic to the clivus, simulating meningitis: case report.

Ewing's sarcoma, which is regarded as one of the most lethal primary bone tumors, lies in the domain of the orthopedic surgeon because it occurs most commonly in the shaft of the long bones, especially in the lower extremities. Pain, leukocytosis, fever, anemia, and an elevated erythrocyte sedimentation rate are commonly seen. We are presenting a case of Ewing's sarcoma of the left greater trochanter with metastasis to the clivus producing a bilateral 6th nerve palsy. The presence of fever, nuchal rigidity, and photophobia simulated meningitis. The rapid evolution of radiological signs will be discussed.

Abducens Nerve↗
PubMed1980

A monoclonal antibody defining a lymphoma-associated antigen in man.

A monoclonal antibody (Ab 89) was developed against a lymphoma-associated antigen on the tumor cells of a patient (N.B.) with a B cell, poorly differentiated lymphocytic lymphoma (D-PDL). By indirect immunofluorescence, Ab 89 was shown to react only with N.B. lymphoma cells and was unreactive with normal N.B. lymphoid cells, normal fractionated peripheral blood cells, other normal lymphoid tissues, fetal tissues, and non-lymphoid malignant cells. In addition, Ab 89 was unreactive with conventional immunoglobulins, private and public HLA antigens, or Ia-like antigens. More importantly, Ab 89 was reactive with some B cell lymphoid malignancies. Of the 57 B cell lymphomas tested, it was found that Ab 89 reacted with approximately 10% of B cell D-PDL and B cell chronic lymphocytic leukemia (CLL). Of interest was the finding that N.B. serum contained a circulating antigen which could specifically block the reactivity of Ab 89. The data obtained suggests that Ab 89 defines a tumor-associated antigen shared by a unique subgroup of B cell lymphomas. The group of patients reactive with Ab 89 did not fall into any histopathologic classification system. These data support the notion that there is greater heterogeneity of B cell lymphomas than may have been previously recognized.

Absorption↗
PubMed1980

Characterization of a human B lymphocyte-specific antigen.

A human B lymphocyte-specific antigen (B1) was identified and characterized by the use of a monoclonal antibody. By indirect immunofluorescence, cytotoxicity, and quantitative absorption, B1 was present on approximately 9% of the peripheral blood mononuclear cell fraction and >95% of B cells from blood and lymphoid organs in all individuals tested. Monocytes, resting and activated T cells, null cells, and tumors of T cell and myeloid origin were B1 negative. B1 was distinct from standard B cell phenotypic markers, including Ig and Ia antigen. Removal of the B1 positive population in peripheral blood eliminated all B cells capable or responding to pokeweed mitogen by maturation to Ig-producing cells.

Absorption↗
PubMed1980

Serotherapy of a patient with a monoclonal antibody directed against a human lymphoma-associated antigen.

A preliminary serotherapeutic trial was undertaken with a monoclonal antibody designated antibody 89 (Ab 89) directed against a lymphoma-associated antigen. In vitro studies demonstrated that Ab 89 could mediate complement-dependent lysis and macrophage adherence but not antibody-dependent cell-mediated cytotoxicity. To evaluate toxicity and therapeutic efficacy, two courses of Ab 89 were administered to a patient with an Ab 89-reactive tumor. Transient decreases in the number of circulating tumor cells and the appearance of circulating dead cells were noted with the infusion of Ab 89. Following administration of 150 mg or more of Ab 89, small amounts of antibody could be demonstrated on circulating tumor cells at a time when no free antibody was found in the serum. The inability to deliver a significant amount of Ab 89 to tumor cells in vivo is thought to be secondary to a circulating tumor antigen. Following each infusion, the amount of this blocking antigen decreased but could not be entirely cleared from the serum. This study provides preliminary evidence for the lack of clinical toxicity of a monoclonal antibody and identifies circulating blocking antigens as a significant obstacle to serotherapy.

Antibodies, Neoplasm↗
PubMed1979

A computer program for life table regression analysis with time dependent covariates.

This paper presents a computer program for analyzing time-dependent covariables in survival studies by the life table regression model described by Holford [3]. Basically, life table regression incorporates the elements of regression and the life table into a single model. Regression parameters are estimated by the method of maximum likelihood using the Newton-Raphson iterative procedure. The program provides two methods for testing hypotheses concerning regression coefficients, namely the standard normal deviate test and a Wald statistic based on the first and second derivatives of the log likelihood. Residual plots are provided to assess the fit of the model to the data.

Actuarial Analysis↗
PubMed1979

Differentiation of fluorescent pseudomonads by their effect on milk agar.

Eighty-six clinical isolates of fluorescent pseudomonads that did not produce pyocyanin on Diagnostic Sensitivity Test Agar or Cetrimide Agar were identified on the basis of their antibiotic sensitivity, production of pigment on King's "A" medium, growth at 42 degrees C, production of lecithinase and hydrolysis of gelatin. The identity of the strains was confirmed in tests with the ammonium salt sugars ethanol, glucose and mannitol. These tests were adequate for distinguishing between the three important fluorescent pseudomonads. The detection of casein hydrolysis on milk agar was assessed as a rapid method of distinguishing P. aeruginosa from the other species of fluorescent pseudomonads but proved unhelpful when compared with, or included in, a small set of tests. Most strains of P. aeruginosa and P. fluorescens hydrolysed casein.

Agar↗
PubMed1978

Occurrence and fate of organic and inorganic contaminants in marine animals.

Most chemical contaminants occur in highest concentrations in coastal waters, often maximized in very localized areas. In general, this situation represents the exposure pattern for marine animals. However, the availability of contaminant to an organism depends not only on its concentration but also on its chemical nature, its physical state, and whether the source of exposure is the surrounding seawater or the diet. Depending on the type of exposure, uptake occurs across absorptive surfaces, such as those of the respiratory apparatus or gastrointestinal tract, where selectivity may occur, even among neighboring homologs. Deposition in tissues, accumulation, degradation, or depuration depends on tissue type, metabolic processes, detoxification mechanisms, and the adaptive status of a particular animal. This hypothesis is examined briefly for hydrocarbons, pesticides, other miscellaneous organic contaminants, heavy metals, and radionuclides. It is concluded that most data relate to occurrence and distribution. Considerably less information is available on the underlying biochemical processes.

Animals↗
PubMed1977

Use of transcutaneous electrical stimulation in the control of postoperative pain.

Perception and relief of pain were studied in a varied group of fifty patients who had undergone laparotomy with upper abdominal midline incisions. Twenty-six patients were supplied with functioning transcutaneous electrical stimulators. Twenty-four received nonfunctioning machines. The controls were randomized by a nurse not otherwise involved in this study. Only seventeen of the total study group were judged failures and six of the patients had been receiving preoperative narcotics. Patient response was very favorable and pain relief was good to excellent, especially in one group with working stimulators (p is less than 0.008). Patients with known malignant disease did not respond as well as those with benign disease although anxiety may have been an important factor here. Use of the transcutaneous electrical stimulator would seem particularly worthwhile for patients undergoing elective abdominal operations for benign disease with no history of narcotic usage. Briefing the patient preoperatively on the potential value of transcutaneous electrical stimulation as a method of pain relief may improve end-results.

Adult↗
PubMed1977

Muscle fiber number in immobilization atrophy.

Eight Sprague-Dawley rats 10 to 12 weeks of age had one limb immobilized by plaster in knee flexion and ankle plantar flexion for four weeks. The soleus muscles from the control and immobilized limbs were excised and frozen. The technique used insured that cross sections subsequently cut and stained would contain all the fibers extending from the origin to the insertion aponeuroses. The total number of muscle fibers per muscle was counted from 25 to 50 photomicrographs made for each muscle cross section. Paired comparisons of total muscle fibers in control and immobilized muscles revealed no significant differences. The total number of fibers in control and immobilized soleus muscles was 2812 +/- 521 and 2930 +/- 403, respectively. Therefore, muscle fiber loss does not occur in disuse atrophy produced by external immobilization as has been reported.

Animals↗
PubMed1976

Revised laboratory manual helps solve problems.

This paper describes a project to design a laboratory manual which could be easily understood and used by both those who work in and those who utilize the laboratory in a large teaching hospital complex. Results indicated increased employee knowledge of laboratory policies and procedures, and an improved relationship between patient units and the laboratory.

Alabama↗
PubMed1975

Age-dependent characteristics of compensatory renal growth.

The age-dependent characteristics of compensatory renal growth were studied in neonatal, weanling and young adult rats. Compensatory growth was demonstrated to be greater in young, sexually immature animals than in adults following unilateral nephrectomy. In the four-week interval following surgery in 21-day-old weanling rats, renal mass increased 240% in control animals (group A) and 407% after unilateral nephrectomy (group B). In similarly prepared adult animals, renal weight increased 31 and 81% in the same groups, respectively. The remarkable response in compensatory growth achieved by the young animal was further demonstrated by a greater absolute increase in renal mass in the experimental kidney of young rats compared to adults. Further studies were performed to determine whether the mechanism of compensatory growth in young rats involved formation of new nephrons. The total glomerular count in the remaining kidney of rats after removal of one kidney at 5 (neonatal) and 21 (weanling) days of life did not differ from the value obtained in control neonatal, weanling or adult kidneys. These data indicate that compensatory renal hypertrophy is age-dependent and is greater in young animals. The mechanism for enhanced compensatory renal growth in young animals does not involve glomerular neogenesis since there was no evidence for formation of additional nephrons following nephrectomy either in weanling or neonatal animals.

Aging↗