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Biomedical subjects

D Carr

Publications and source records attributed to D Carr.

At least 91 records · Page 5Linked to original sources

Pulmonary haemorrhage complicating Wegener's granulomatosis and microscopic polyarteritis.

The incidence and characteristics of pulmonary haemorrhage in a series of 89 patients with systemic vasculitis were analysed. Pulmonary haemorrhage occurred in 32 of these patients and was associated with haemoptysis in all 32, alveolar shadowing in the chest radiograph in 28, and a significantly raised transfer coefficient in 30. Pulmonary haemorrhage usually resolved with treatment by immunosuppressive drugs but was the cause of death in 11 patients. In contrast with patients with antibasement membrane antibodies there was no correlation between pulmonary haemorrhage and cigarette smoking. Pulmonary haemorrhage is a cause of serious morbidity in patients with systemic vasculitis.

Arteritis↗

Distal posterior interosseous nerve syndrome.

Six patients selected from 13 patients presenting with dorsal wrist pain related in onset to repetitive dorsiflexion maneuvers are described. Clinical examination revealed tenderness over the fourth extensor compartment. Wrist dorsiflexion reproduced their symptoms. All patients were relieved by selective bupivacaine (Marcaine) block of the posterior interosseous nerve 3 cm proximal to the wrist joint. Of the 13 patients presenting, seven improved on immobilization and anti-inflammatory drugs. The six patients not relieved underwent surgical exploration with the specific findings of an enlarged, fibrotic, posterior interosseous nerve. Histologic analysis revealed perineural fibrosis without inflammatory changes. The perineural fibrosis was four times greater in affected nerves than in control specimens. We propose distal posterior interosseous nerve syndrome as another entity causing dorsal wrist pain that is distinct from the usual causes, such as dorsal ganglia, degeneration of the scapholunate ligament, and dorsal wrist syndrome.

Adult↗

Immunologic evaluation in the nutritional assessment of children with cancer.

Eighty-one newly diagnosed untreated pediatric cancer patients (48 hematopoeitic malignancies, 17 solid tumors, 16 benign diseases) were evaluated with immunologic and nutritional parameters. The mean absolute lymphocyte count was adequate in the three groups. Reduced T-lymphocytes were seen in the solid tumors. Mitogenic response of hematopoietic and solid tumor patients' lymphocytes was low. Correlation of immunologic, dietary, and nutritional factors showed that for patients with solid tumors there was a positive significant correlation between weight/height percent and lymphocyte reactivity to phytohemagglutinin, concanavalin A, and pokeweed mitogen (p less than .05). Iron intake showed a significant positive correlation with in vitro mitogen reactivity for the solid tumor group (p less than .05) and benign diseases (p less than 0.01). Immune derangements found among patients with hematopoietic malignancies can be due to replacement of normal bone marrow with malignant cells. In solid tumor patients mitogen reactivity appears to be a reflection of nutritional state, and dietary iron is a possible factor.

Adolescent↗

Lumbar paraspinal compartment syndrome. A case report with physiologic and anatomic studies.

A 24-year-old man presented with severe low-back pain and paraspinal muscle spasm after exertion. Elevation in temperature, white blood cell count, serum muscle enzymes, and urine myoglobin, as well as computer tomographic evidence of paraspinal muscle edema and necrosis, were present. No etiology could be documented, and the possibility of an acute exertional compartment syndrome was entertained. Subsequently, cadaveric dis-sections indicated that the erector spinae muscles are contained within a well-developed fascial sheath. Continuous slit catheter pressure measurements within this compartment in eight healthy male subjects were subsequently carried out. These indicated a physiologic behavior similar to other known compartments for which compartment syndromes have been described. Variation in intracompartmental pressure occurred as a function of body posture, erector spinae isometric contraction, and active intra-abdominal pressurization. We suggest this patient had a paraspinal compartment syndrome and have described pressure characteristics of this compartment in normal men.

Adult↗

Tetracyclines of various hydrophobicities as a probe for permeability of Escherichia coli outer membranes.

The outer membrane of gram-negative cells excludes hydrophobic molecules and is responsible for the resistance of these cells to a number of dyes, detergents, and antibiotics. We describe a test for hydrophobic permeability in which a series of tetracyclines with various hydrophobicities are used. Normal Escherichia coli cells became more resistant as hydrophobicity was increased in this series, but mutants altered in outer membrane permeability remained susceptible. A mutant lacking all polysaccharide except 2-keto-3- deoxyoctonic acid in its lipopolysaccharide is virtually as susceptible to the hydrophobic drug 13- phenylmercapto -alpha-6- deoxytetracycline as to oxytetracycline (MIC 100 times lower than that of the wild type), and a mutant with another, as yet undefined outer membrane defect, acrA , also shows increased, although somewhat lesser, susceptibility (MIC 20 times lower than that of the wild type). Increased susceptibility to this tetracycline derivative is associated with greater fluorescence of the derivative when added to the cells, which we interpret as increased interaction of the derivative with hydrophobic domains, such as membranes, in the mutants. This series of tetracyclines may provide an assay for measuring the permeability of gram-negative organisms and their mutants to hydrophobic molecules.

Cell Membrane Permeability↗

Spontaneous and induced metastasis of naturally occurring tumors in mice: analysis of cell shedding into the blood.

The lung colonization capability (after iv inoculation) of each of 77 autochthonous virus-induced mammary tumors in C3H/Avy female mice was compared with its own spontaneous metastatic behavior. Twenty-four of these neoplasms had spontaneously metastasized to the lungs of the tumor bearer. The results were interpreted in the framework of dose-response studies on experimentally induced metastasis. These results indicate that tumors of high lung colonization potential (HCP) overgrow the lungs with iv doses as low as 10(4) cells, whereas tumors of low lung colonization potential (LCP) require at least 250 times this dose to achieve the same result. No general similarity was found between spontaneous and induced metastatic capability. Although some tumors showed good correspondence, others showed discrepancies and provided new information on mechanisms of cell shedding from primary tumors and on rate-limiting steps in metastasis. For example, from the dose-response studies, nonmetastatic tumors of HCP (iv) are deduced to be shedding very few cells. These findings suggest that escape from the primary tumor is an active process or else passive leakage of cells into vessels by hemorrhage, necrosis, or palpation should have resulted in spontaneous metastasis. Spontaneously metastatic tumors of LCP corroborate the view that metastasis is effected by a highly active subpopulation with special properties; otherwise, the required scale of passive cell release into the blood would be unrealistically large. Blood bioassay and time-course studies on pulmonary deposit formation indicate that shedding of metastatic cells occurs early in mammary tumor development.

Animals↗

Preoperative diagnosis and its effect on the treatment of carcinoma of the gallbladder.

In 19 patients with carcinoma of the gallbladder treated over a four year period, several features of percutaneous transhepatic cholangiography have been recognized which have increasingly provided an accurate diagnosis preoperatively. These features are due to intrahepatic invasion of the bile duct and by providing a diagnosis preoperatively can have a large bearing on the choice of therapy for a particular patient. The relative roles of surgical bypass and endoscopically or percutaneously placed prostheses are discussed.

Adult↗

Energy and nutrient intake of children with cancer.

Two hundred seventy-seven pediatric cancer patients received a nutritional assessment. Initial dietary intakes of patients with no prior treatment indicated a diet similar to that of the general population. The caloric intake was 75% of the RDA in a group of patients with non-malignant diseases and 80% of the RDA in the groups of patients with solid tumors and hematopoietic malignancies. Protein intake was greater than 100% of the RDA for all groups. Dietary iron was the nutrient lowest in intake, with a range of 70% to 78% of the RDA. At six-month evaluations, no significant changes occurred except for an increase in iron, niacin, riboflavin, and protein intakes in the group with solid tumors.

Adolescent↗

Nutritional parameters in children with cancer.

An analysis of commonly used nutritional parameters was made for 277 pediatric cancer patients. It is apparent that standard nutritional assessment parameters in the pediatric cancer patient may be difficult to interpret because of the disease state as well as of the treatment. On the basis of the findings of this study, dietary histories to determine caloric and protein adequacy and a measurement of weight/height percent may, in fact, be the most reliable indicators of nutritional status.

Adolescent↗

Experimental analysis of factors affecting metastatic spread using naturally occurring tumours.

This paper describes the applications and latest results of recently developed techniques in metastasis research using naturally occurring animal and human tumours. Intravenous inoculation of cells from murine mammary tumours into syngeneic recipients has shown that some are consistently capable of heavy pulmonary colonisation (HCP) while others have low colonisation potential (LCP). These distinct characteristics are stable over wide cell-dose ranges. Autopsies on a sample of 100 consecutive tumour-bearing C3H/Avy mice revealed that the incidence of spontaneous metastasis is 26%. When inoculated intravenously, cells from some of the spontaneously metastatic primary tumours had HCP and others LCP. We now report that, knowing the degree of pulmonary colonisation of a particular tumour after intravenous inoculation, the degree of its spontaneous metastasis in the original host, and the dose-response relationships mentioned above, it is possible to back-titrate the degree of cell shedding from the tumour into the blood stream. Other experiments reported here demonstrate that separate mammary tumours on the same animal have independent colonisation potentials and growth rates, that tumours appearing later on an animal are not necessarily more capable of metastatic spread than the earlier ones, and that tumour weight and length of presence on the host do not show any strong correlation with spontaneous metastatic spread. A moderately significant association between pulmonary colonisation potential and tumour growth rate is reported and evidence corroborating our earlier observations that ability to colonise the lungs is possessed only by neoplastic mammary cells is also presented. Similar investigation are, of course, much more difficult to organise on tumour spread in man because of ethical and logistic considerations but it is possible to circumvent some of these difficulties and we refer to some of our ongoing studies.

Adipose Tissue↗

The role of bone scanning in Paget's disease.

In Paget's disease, the bone scan allows visualisation of the whole skeleton, permitting accurate assessment of disease extent. The scan appearances are usually characteristic, and as uptake of tracer depends upon skeletal metabolic activity, this study reflects the severity of Paget's disease, in addition to providing early appreciation of alterations in disease activity. While correlation of x-rays and bone scans in Paget's disease have shown that neither method alone detects all lesions, it is clear that the bone scan is the more sensitive technique. In addition, those sites that are occasionally missed by bone scan are metabolically inactive. The bone scan is the investigation of choice in Paget's disease, and radiology should be used to provide supplementary information, as and when required.

Bone and Bones↗

Does inhibition of prostaglandin synthesis increase the diagnostic accuracy of the intravenous urogram in renal artery stenosis?

Intravenous urography is the standard screening test for renovascular hypertension but there is a significant incidence of false negative and false positive results. In an attempt to improve the detection rate, indomethacin was administered orally to nine patients with renal artery stenosis (proven by arteriography and by divided ureteric function studies) before rapid-series intravenous urography. This urogram was compared independently by two observers with prior similar-series urograms. Indomethacin did not alter diagnostic accuracy.

Adolescent↗