Biomedical subjects
Publications and source records attributed to D Lee.
'Naturally occurring' anti-D has been studied in four Rh(D) negative males. The presence of this anti-D does not preclude successful deliberate immunization of Rh(D) negative volunteers; 'naturally occurring' anti-D does not provide a marker of non-responders to Rh immunization. 'Naturally occurring' anti-D is not necessarily the result of materno-fetal transfusion at birth.
The effects of pretreatment of rats with phenobarbitone, clofibric acid and spironolactone on the metabolism and biliary excretion of the salicylate derivative diflunisal have been studied using the isolated perfused liver. The clearance of diflunisal was increased significantly by pretreatment with each of the drugs. Biliary excretion of diflunisal acyl and phenolic glucuronides followed apparent first-order and Michaelis-Menten kinetics, respectively. Pretreatment with clofibric acid or spironolactone resulted in a significant increase in the biliary excretion of the phenolic glucuronide. Pretreatment with phenobarbitone or spironolactone enhanced biliary excretion of the acyl glucuronide, particularly during the first 2 hr. The concentration of the phenolic glucuronide in the perfusate increased steadily during the 6 hr perfusions, whereas the acyl glucuronide concentration was relatively stable, reflecting the ease of hydrolysis of acyl glucuronides under physiological conditions.
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Immunological techniques have been used to identify and quantitate rabbit antibody light chains in the urine of rabbits. The influence of these light chains on the radioallergosorbent test (RAST) used for the diagnosis of laboratory animal allergy to rabbit urinary protein allergens is described. The presence of IgG antibody specific for rabbit derived antigens in human serum has been confirmed.
A histological review of 1003 invasive breast carcinomas identified 103 patients with infiltrating lobular carcinoma, for whom clinical and survival data were collected in each case. Six patients had bilateral carcinoma at diagnosis and 14 developed a contralateral carcinoma during the period of follow-up. The major factor predicting patients at risk of developing a contralateral carcinoma was histological type. Analysis of survival data on the patients with bilateral disease showed poor survival in the group with synchronous bilateral disease, but no difference in survival between patients with metachronous bilateral and unilateral disease. This suggests that the development of a metachronous contralateral carcinoma does not necessarily reduce the probability of survival of patients with infiltrating lobular carcinoma.
A variety of acrylic bone cement-metal composite materials were prepared and tested in simple compression at 37 degrees C in order to evaluate the mechanical behavior of these materials for possible use in bone replacement. The stiffness of the composite was of particular concern, and a simple rule of mixture was used to raise the modulus of acrylic bone cement. The reinforcement of the cement was accomplished by titanium and Ti-6Al-4V in different forms, e.g., wire, sheet, wire mesh, and powder. Test results demonstrated that the stiffness of the bone cement could indeed be increased by a desired amount to that of bone. A 16% volume fraction consisting of 25 0.10 cm diam Ti-6Al-4V wires increased the modulus of the bone cement by 380% to a value comparable to the modulus of cortical bone. Titanium sheet was nearly as effective as wires in increasing the modulus of bone cement, while titanium mesh was not a significantly effective reinforcing material. The amount of titanium powder added to the bone cement did not alter the compliance of the matrix material. In addition, as the flow strength increased, the strain to the point of load instability decreased. It was concluded that the extent of stiffening was governed by nonuniform deformation in the metal and the adjacent matrix which could be explained on the basis of geometrical considerations. Some of the limitations of the test results as well as methods of predicting the composite implant material behavior are also outlined.
A survey of the prevalence of laboratory animal allergy to rats, mice, guinea pigs and rabbits among sixty-nine animal workers and 308 other subjects on a pharmaceutical research site revealed a 22% prevalence of laboratory animal allergy among the animal workers. The overall prevalence of atopy was 67% in persons with allergy to laboratory animals. This was significantly greater than the 31% prevalence in other animal workers. Skin-prick tests and specific IgG and IgE assays to urinary protein extracts strongly correlated with the occurrence of laboratory-animal allergy and would appear to have diagnostic value. However, a number of clinically diagnosed laboratory-animal-allergy subjects gave no evidence of immunological response to the urinary allergens and wider diagnoses may have to be applied in these cases.
A histological review of 1003 invasive breast carcinomas identified 51 tumours in which the invasive component showed a predominantly cribriform pattern. These separated into two groups; 35 which showed exclusively cribriform or cribriform with a limited extent of tubular invasive elements only, designated 'classical' invasive cribriform carcinoma and 16 which also contained areas of less well differentiated invasive carcinoma, designated 'mixed' invasive cribriform carcinoma. At follow-up, 10 to 21 years after diagnosis, none of the 35 patients with classical invasive cribriform carcinoma had died as a result of this initial carcinoma and 30 remained alive. Of the 16 remaining patients, whose tumours showed areas of less well differentiated carcinoma, only six remained alive. However, the adjusted 10 years survival rate of these patients in this mixed group was significantly better than that of invasive carcinoma in Edinburgh. Invasive cribriform carcinoma in its classical form, is a histological subgroup of invasive carcinoma with the same excellent prognosis as that of invasive tubular carcinoma.
We developed a simple, direct, physical assay to detect genetic recombination of bacteriophage T7 DNA in vitro. In this assay two mature T7 DNA molecules, each having a unique restriction enzyme site, are incubated in the presence of a cell-free extract from T7-infected Escherichia coli cells. After extraction of the DNA, restriction enzyme digestion, and agarose gel electrophoresis, genetic recombination is detected by the appearance of a novel recombinant DNA band. Recombination frequencies as high as 13% have been observed. We used this assay to determine the genetic requirements for in vitro recombination. In agreement with results obtained previously with a biological assay, T7 recombination in vitro appears to proceed via two distinct pathways.
Radioallergosorbent tests (RAST) using urinary proteins from mice, rats, guinea pigs and rabbits have been developed and used in the diagnosis of laboratory animal allergy (LAA). Of the 273 subjects tested, 15 had been previously diagnosed as laboratory animal allergic and 8 of these (53%) gave one or more positive RAST results. Of the 258 symptom-free individuals, only 9 (3.5%) had one or more positive RAST. Of these 9, 7 had previously worked with animals or had occupational exposure to the appropriate species; the remaining 2 individuals had only some pet exposure. RAST was, therefore, of value in the diagnosis of LAA. During the development of these RAST assays, several sources of potential error were identified. Modest titres of total IgE (600 IU/ml and above) were found to influence the specific RAST index observed and lead to false positive results. The presence of human IgG antibody specific for rabbit serum proteins was also identified in four sera, and was responsible for interference in the rabbit urinary protein RAST system.
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Dicalcium phosphate dihydrate, CaHPO4 . 2H2O (DCPD) crystals were grown in solutions and in different types of gels (silica, agar, collagen) at different pH's, in the presence of other ions, and on different Ca-bearing substrates (enamel, dentine, bone, calcite). Hydrolysis of DCPD to other calcium phosphates and calcium oxalates were made in solutions containing different ions at 37 degrees C, 24h. Results showed that the type of media (solution or gel), type of gel, pH, presence of other ions affect the morphology (size/shape) and growth of DCPD. In systems of changing pH, the more basic calcium phosphate (e.g., apatite, OCP) formed in the first zone, DCPD in the last zone, regardless of the initial Ca/P of the system. Growth of DCPD was suppressed in the presence of F-(which favored growth of apatite), of Cd2+, Pb2+ (which favored OCP). Hydrolysis of DCPD to apatite was promoted in solutions containing Ca2+, F-, CO3=, and inhibited by Mg2+, P2O74-. Hydrolysis of DCPD to calcium oxalate occurs in presence of C2O4=. Results indicate that the variation in morphology of DCPD occurring in various human tissue calcinosis and the co-existence of DCPD with other calcium phosphates and oxalates in urinary and dental calculi are due to variations in pH, and presence of different ions in the media.
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The effect of preoperative intraparietal (intra-incisional) injection of cefoxitin along the site of the intended incision on the incidence of wound infection has been investigated by a randomized prospective study of 181 consecutive patients undergoing abdominal surgery. A significant reduction in wound infection was evident in the cefoxitin-treated group (4.4 per cent) when compared with controls (16.7 per cent) (chi 2 = 6; P = 0.02). Administration of antibiotic by this route did not delay wound healing or produce any undesirable sequelae.
Sixteen women with a clinical diagnosis of inflammatory breast carcinoma had estrogen receptor analysis performed. Eleven of 16 were premenopausal. Median age of all patients was 46 years. All patients had estrogen receptor (ER) assay by either dextran charcoal method or by sucrose gradient method. Five patients were ER + ( greater than or equal to 10 fmol/mg cytosol protein) and 11 were ER -, with almost no binding at all. Response to therapy for metastatic disease using either hormones or chemotherapy was disappointing.