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Biomedical subjects

W M Ross

Publications and source records attributed to W M Ross.

At least 73 records · Page 4Linked to original sources
PubMed1977

Lymphocytosis induced by polyanions in rats.

More than twenty different polymers, mostly polyanions, were tested in rats for their ability to mobilize lymphocytes into the peripheral blood within 2--3 h. The various polyanions differed in basic structure, in side-chain (size and type), in molecular weight and configuration and in amount and type of anionic charge along the molecule. Neutral polymers and a polycation were also tested for comparison. Some of the polyanions were found to be very effective, others less so and some completely ineffective. Some were also toxic. The basic polymer to which the others were compared was polymethacrylic acid (PMAA), an already recognized mobilizing agent. The best agents were the heparinoids, sulphated polyanions, and the best of these, causing a 3--4-fold increase, were dextran sulphate and polyvinyl sulphuric acid (PVSA). Heparin, although the strongest anticoagulant, was the weakest mobilizer. Some factors that appear capable of modifying mobilization to varying degrees were molecular weight, size and configuration, sulphate content and mode of administration. In the case of PVSA, the smaller molecular weight substance gave a more prolonged lymphocytosis in blood. The high molecular weight substance gave a peak after 2 h, slightly earlier than with PMAA (2--3 h). The administration of protamine chloride to the rat (i.v.) caused an immediate reversal of mobilization, following a course to control values which was essentially identical to the normal decline, only earlier. Dextran sulphate of low molecular weight seems to be the polyanion of choice in subsequent mobilization experiments dealing with determination of the specific mononuclear cell type being mobilized. The single factor that all mobilizing polyanions have in common is a negative molecular charge. It is not yet known exactly how this charge induces the mobilization of mononuclear cells, nor what causes the variability in effectiveness among polyanions.

Acrylamides↗
PubMed1977

Computer-aided medical decision making in radiotherapy.

Radiotherapy departments are becoming sophisticated in working with computers for isodose computations, treatment machine verifications and administrative and medical records. The next step lies in computer-assisted medical decision making. The logic for a patient's diagnostic work-up and treatment protocol can be stored in a computer. It can then be used as an aid in making the diagnosis, in prescribing the treatment and for quality control. For patients who fit established protocols the computer can select and list treatment using the logic of that protocol. Such a system has been implemented for the postoperative radiotherapy of breast cancer on a trial basis. Its potential usefulness is illustrated by results in 25 consecutive patients. Physician acceptance and costs of the program are under investigation.

Breast Neoplasms↗
PubMed1977

In-vitro and in-vivo properties of canine blood mononuclear leukocytes separated by discontinuous albumin density gradient centrifugation.

Dogs were given 1 200 R whole body x-irradiation and transfused with frozen and thawed mononuclear leukocytes from a DLA identical, MLC negative donor dog. These leukocytes had been obtained from the peripheral blood by means of leukapheresis, using the IBM experimental cell separator after injection of 15 mg/kg body weight of dextran sulphate to increase the yield of CFUc upon collection. The segregation of leukocytes by means of the discontinuous albumin gradient centrifugation method resulted in a fraction 2 that contained a very high proportion of CFUc, and in other fractions 3 and 4 with a high proportion of lymphocytes with few CFUc. The dog receiving fraction-2 cells showed a rapid bone marrow recovery (permanent) and displayed no signs of gvh-reaction. The dogs receiving cells of fraction 3 or 4 died of gvh-reaction within 25 days. The dog receiving fraction 4 cells showed little hemopoietic recovery, but a marked lymph node hyperplasia of plasma cells.

Animals↗
PubMed1976

The treatment of mixed parotid tumours by enucleation and radiotherapy.

A series of mixed parotid tumours treated by simple enucleation and radiotherapy between 1962 and 1968 is discussed. There were 73 primary and 8 recurrent cases. Only 2 small recurrences occurred in the 73 primary cases, although 4 other patients were lost to follow-up after 7 years or more. In the 8 recurrent cases, 7 had been treated elsewhere by enucleation alone, thus confirming the opinion that this operation is frequently unsuccessful. Treatment was by further local excision and radiotherapy and no recurrences have occurred. The view is therefore expressed that simple enucleation and radiotherapy is the treatment of choice in all primary mixed parotid tumours.

Adenoma, Pleomorphic↗
PubMed1976

Banding analysis of the somatic chromosomes of the domestic dog (Canis familiaris).

The chromosomes of the domestic dog (Beagle) were investigated by several different staining techniques. G-banding, Q-banding, and the bis-benzimidazol derivative Hoechst 33258, make possible the identification of all 39 chromosome pairs. Constitutive heterochromatin (C-bands) was present on a few chromosomes as distinctive, large stained areas; on the other autosomes there was little or no heterochromatin detectable.

Animals↗
PubMed1975

Polymethacrylic acid: induction of lymphocytosis and tissue distribution.

Polmethacrylic acid (PMAA) induces up to a three-fold increase in the lymphocyte population of peripheral blood in rats, goats and calves after intravenous administration. Other routes of administration are less effective. A maximum lymphocytosis is achieved after 3 hr with all doses in excess of 30 mg PMAA/kg body weight; over the next few hours the lymphocyte level declines to normal. Granulocytes increase steadily for the first 7 hr before declining. Multiple doses of PMAA 2 hr apart failed to maintain or significantly alter the lymphocytosis. PMAA was labelled with 125I and 14C, and was traced to various sites in the rat. The greatest accumulation of radioactivity was in the spleen, lungs, liver, kidney, adrenals and mesenteric lymph nodes (with 14C-PMAA). The accumulation appeared more specific for spleen and lymph nodes since there was only a small loss of activity following removal of blood by whole body perfusion. This supports previous findings indicating that these two tissues play a major role in the development of lymphocytosis. Accumulation in the bone marrow may be indicative of stem cell mobilization. The results are discussed in terms of the lymphocytosis-inducing mechanism and the site of action of PMAA and the possible clinical application to ECIB therapy is considered.

Acrylic Resins↗
PubMed1970

The 131-I ortho-iodohippurate photoscan in human renal allografts.

Nine examples, in seven patients, from a large cadaver renal allograft program, illustrate the value of radio-hippuran photoscans in differentiating causes of post-implant oliguria. Hippuran scans are shown to be more valuable than chlormerodrin scans when renal function is acutely depressed. Hippuran scans aided in the decision to remove kidneys in four cases of severe oliguria and to retain kidneys in two others. In two further examples, extravasation of urine was detected by scanning after radio-hippuran injection when other tests had failed to do so.The technique of radio-hippuran scanning has a place in the differentiation of acute and subacute renal dysfunction and has proved particularly valuable in the early oliguric complications of a cadaver renal transplant program.

Adult↗