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Biomedical subjects

J H Anderson

Publications and source records attributed to J H Anderson.

At least 127 records · Page 7Linked to original sources
PubMed1990

Randomized, prospective study of nail bed ablation for recurrent ingrowing toenails.

A consecutive series of 31 recurrent ingrowing toenails, which had previously undergone at least two surgical procedures, were recruited to this study over a 1-year period. Patients were randomly allocated to one of two treatment groups. Group A underwent nail bed excision whilst group B had nail bed phenolization in addition to excision. Patients were reviewed 2 weeks and 1 year after operation. Seven toes (41%) in group A developed postoperative infection compared with only one (7%) in group B (P less than 0.01). Recurrent nail spicules occurred in ten patients (59%) in group A and six patients (43%) in group B 1 year after operation. High failure rates for ablation of recurrent ingrowing toenails should encourage greater efforts towards adequate treatment at the first presentation.

Adolescent↗
PubMed1990

Effect of superoxide dismutase in rabbits with peritumoral edema.

We evaluated the effect of SOD, an oxygen-free radical scavenger, on peritumoral edema in 20 rabbits. The VX2 carcinoma was transplanted to the brains of these New Zealand white rabbits. Detection of superoxide radicals in vitro was performed by incubating the VX2 tumor cells with NBT. For evaluation of the effect of SOD on the tumor cells, they were treated with free SOD or PEG-SOD before and after incubation with NBT. The animals were separated into three groups: group 1, control group; group 2, SOD-untreated tumor group; group 3, two SOD-treated groups-group 3a, treated with 10,000 U/kg PEG-SOD on day 1 and 4 after tumor transplantation and sacrificed on day 13; group 3b, treated with 10,000 U/kg PEG-SOD on day 7 and 10 and sacrificed on day 13. Brain edema was assessed by SG measurement. Our preliminary in vitro data indicated that the VX2 carcinoma produced superoxide radicals but that free SOD and PEG-SOD could not penetrate into tumor cells nor inhibit superoxide radicals. In vivo data also indicated that PEG-SOD failed to reduce peritumoral edema. It was concluded that intracellular uptake or penetration of SOD must first be achieved before any effect on peritumoral edema can be assessed.

Animals↗
PubMed1990

Lymphocele: the spectrum of scintigraphic findings in lymphoceles associated with renal transplant.

Lymphocele is a well recognized complication of renal transplant surgery. We performed a retrospective review of 305 renal transplant patients with over 2,500 scintigraphic exams to describe the pattern of activity on technetium-99m-DTPA blood flow and dynamic imaging, and iodine-131-OIH studies. Diagnostic criteria for a lymphocele were ultrasonic evidence of a perirenal fluid collection and analysis of that fluid that demonstrated BUN, creatinine, and electrolytes similar to the patient's plasma. Scintigraphic findings were attributed to a lymphocele if abnormalities were in the same area as the ultrasound fluid collection. Scintigraphic findings attributable to lymphocele resolved in all patients following surgical drainage or peritoneal window placement. Six of the 11 documented lymphoceles demonstrated a cold defect on initial dynamic images that "filled in" to equal background activity and another exceeded background. Three cases showed a rim of increased activity surrounding the lymphocele ("rim sign").

Follow-Up Studies↗
PubMed1990

Management of patients with thyroid carcinoma: application of thallium-201 scintigraphy and magnetic resonance imaging.

Thyroid carcinoma has the ability to concentrate radioiodine, an attribute that can be used both for detection of thyroid cells and for treatment. Unfortunately, however, radioiodine uptake is not observed in all patients and a radioiodine scan requires that the patient be rendered hypothyroid for 4-6 wk. In the present study, we analyzed the utility of thallium-201 scanning and the usefulness of magnetic resonance imaging (MRI) in the detection of thyroid cancer. Nineteen patients with thyroid cancer had a total of 24 radioiodine scans, 33 thallium scans, and 10 MRI examinations. Of the 19 patients in the study, 17 had differentiated thyroid carcinoma. In these 17 cases, all paired studies were concordant for the presence (n = 7) or absence (n = 10) of disease. However, in one case (Patient 10), the 201Tl studies showed far more extensive disease than was observed on the 131I scan. Thyroid cancer was also detected on seven MRI studies. In summary, thallium and MRI scans are adjunctive techniques to radioiodine scanning that can either confirm the presence of neck bed activity, residual disease or metastatic cancer and may delineate tumor deposits not detected by radioiodine scanning. Thallium may be capable of detecting tumor deposits even while a patient remains euthyroid.

Adenocarcinoma↗
PubMed1990

The acetabulum: a prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty.

Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy (111In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ form that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and 111In-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on 111In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

Acetabulum↗
PubMed1989

Compensatory eye movements during head and body rotation in infants.

Eye movements were measured in 2- and 4-month-old infants during rotation in the light and in the dark using a specially constructed infant seat that was rotated sinusoidally at 0.1, 0.25 and 0.5 Hz. As in adults, the phase of the vestibulo-ocular reflex (VOR) was nearly compensatory with respect to head position, and the gain values were generally in the range between 0.4 and 1.4. There were two types of phases for the cervico-ocular (COR) responses: compensatory and anticompensatory. The gain of the COR was 4-6 times larger than that reported for adults. In addition, it was both frequency- and age-dependent. These characteristics of the COR may reflect developmental processes in the infant nervous system. The interaction of the two reflexes (VOR + COR) gave responses similar to when the VOR was elicited alone. The subjects' use of a fixation light raised the gain of the VOR and VOR + COR to about 1.67 and 1.44, respectively. These values were higher than most gains reported for adults. However, they were close to what was predicted (1.53) for the experimental conditions wherein fixation was on a target 25 cm in front of the eyes.

Eye Movements↗
PubMed1989

A canine model of controlled thrombotic vascular occlusion.

The authors developed a reproducible canine model of arterial thrombotic occlusion. Operative isolation and occlusion of the external iliac arteries (EIA) were combined with balloon de-endothelialization and thrombin injection to induce bilateral thrombosis in 13 dogs. After three to nine days, 26 of 26 vessels contained isolated, discrete thrombi. Arterial blood flow reconstituted at the superficial/deep femoral artery bifurcation in 100% of cases, which limited the distal extent of thrombosis. Arterial dimensions measured intraoperatively showed thrombus volumes to be (mean +/- SD) 1332.1 +/- 243.1 mm3 (right) and 1335.9 +/- 246.8 mm3 (left). A 2-mm hot tip probe powered by an Argon laser was used to recanalize the occlusion in four vessels. Thrombo-ablation volumes accomplished by a single pass of the laser probe averaged 172 +/- 19.7 mm3 per vessel yielding thrombo-ablation energies between 2.6 and 3.5 J/mm3. Quantification of thrombi and simultaneous monitoring of both occluded segments by aortography as well as the large size of the EIA are advantages of this model, which is recommended for studies of thrombotic vascular occlusive disease.

Animals↗
PubMed1989

Porcine model for the development of interventional techniques in the gallbladder.

A technique that permits repeated access to the porcine gallbladder through a surgically placed 18 French latex catheter is described and experience with this system in 22 swine is discussed. This porcine gallbladder model produces a reliable and reproducible means for studying clinically applicable interventional procedures.

Abdominal Muscles↗
PubMed1989

Simple avulsion of onychogryphotic toenails: a justifiable treatment?

Twenty-nine consecutive patients with onychogryphotic toenails in whom conservative treatment had failed, were entered into the study over a one year period and followed-up prospectively for a further year. All patients were treated by simple nail avulsion. The incidence of recurrence was 27 out of 29 patients (93%); only five of these were symptomatic (17%). Only two patients required further surgery. We conclude that simple avulsion of onychogryphotic toenails offers symptomatic relief in the majority of patients, particularly in this elderly population in whom the use of a tourniquet may be contraindicated.

Adolescent↗
PubMed1989

Oxygen free radicals in the genesis of traumatic and peritumoral brain edema.

This study evaluates the effect of superoxide dismutase, a scavenger of oxygen free radicals, on peritumoral and cold injury edema. Vasogenic brain edema was produced in 39 cats by a standardized cortical freezing lesion. Peritumoral edema was produced by the transplantation of VX2 carcinoma cells into the brain of New Zealand White rabbits. Detection of superoxide radicals was studied by topical application of nitroblue tetrazolium to the cortical injury and by incubation of the VX2 carcinoma cells. The animals were treated with free superoxide dismutase (SOD) and polyethylene glycol superoxide dismutase (PEG-SOD). The following groups were studied: 1) control, 2) untreated tumor group, 3) tumor group treated with PEG-SOD, 4) a group treated with PEG-SOD before injury, and 5) a group treated with free SOD after injury. Brain edema was evaluated by measurement of specific gravity and planimetry study of the spread of Evans blue dye. Preliminary data indicate that superoxide radicals are present in the brain after cold injury and in the cytoplasm and nucleus of VX2 carcinoma cells. Free SOD and PEG-SOD had no beneficial effect upon the vasogenic brain edema produced in either model. It is concluded that intracellular uptake of SOD may be one of the factors necessary for an effect upon either form of edema.

Animals↗
PubMed1988

In vivo and in vitro 31P-NMR preliminary studies of the VX-2 carcinoma in rabbits.

In vivo and in vitro 31P-NMR spectroscopy was used to study the high energy phosphate metabolism of VX-2 tumors implanted into rabbit liver, kidney, and hind-limb muscle. Tumors, at various stages of growth, were first examined by in vivo 31P-NMR spectroscopy, then they were excised and underwent histologic examination and biochemical analysis; both in vitro 31P-NMR and standard enzymatic techniques were used. There was good correlation among the in vivo NMR spectra, the in vitro NMR data, and the biochemical analyses. Although the tumor spectra showed characteristics similar to those reported in the other tumor models, there was a striking variability in the spectra obtained from tumors implanted in the same site and from different sites. There was poor correlation between the degree of necrosis in the tumor and the tumor pH and between the Pi:ATP ratio and necrosis. This variability has important implications for the potential value of using 31P-NMR spectroscopy to monitor tumor growth and therapy in vivo.

Adenosine Triphosphate↗
PubMed1988

Labeled plasma metabolites of L-methyl-hydrogen-3-methionine and L-methyl-carbon-14-methionine in the dog.

The validity of the mathematical models that attempt to describe positron emission tomography (PET) images produced with [11CH3] methionine in terms of rates of local cerebral protein synthesis has yet to be established. A major objection to current models is that the use of methionine labeled at the methyl position results in the dispersal of the label among various methyl-accepting compounds that appear in the plasma and may then enter the brain. One approach to overcoming this problem has been the use of "standard" corrections for the activity contributed to plasma by labeled plasma protein and labeled serine. In order to determine the validity of this approach, the metabolic fate of labeled methionine was studied in six dogs. After injection with either [C3H3] methionine or [14CH3] methionine arterial blood was sampled. Plasma fractions containing protein were separated by fast gel filtration, counted with standard scintillation techniques, and their radioactivity was compared with total plasma radioactivity. Plasma was also separated by high-pressure liquid chromatography into methionine, serine, and nonmethionine or serine-containing fractions. These fractions were counted, and their radioactivity was compared with total plasma radioactivity. Labeled protein appeared in plasma about 20 minutes postinjection and then increased steadily. Labeled serine also appeared and reached a peak value of 9.4 +/- 2.1% of plasma activity at 40 minutes. Of greatest interest was the appearance in later plasma samples of increasing amounts of activity contained in nonserine low molecular weight metabolites of methionine. At 40 minutes, those metabolites made up 27 +/- 6.9% of total plasma activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

A labor readiness index (Bishop score) for rhesus monkeys.

A scoring system is presented for quantitative evaluation of labor readiness in macaque monkeys. Cervical position, length, softness and dilation are rated along with fetal head position for a total score of 13. The system is based on experience in evaluating readiness of multiparous rhesus monkeys for labor induction. Guidelines for the examination for use of the score are described.

Animals↗