Microfocal radiography with macroradiographs in osteoarthritis.
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Cartilage, Articular↗
Biomedical subjects
J A Lynch
Publications and source records attributed to J A Lynch.
Comparison of the effects of moist and dry conditions on the process of angiogenesis during dermal repair.
The effect of moist and dry conditions on the process of angiogenesis during dermal repair was investigated. The moist conditions were achieved by covering excised wounds on porcine flank skin with the adhesive polyurethane dressing Opsite and dry conditions were achieved by exposure to air through dry gauze dressings. Angiogenesis was assessed during the period from 3 to 60 d after injury. Quantitative studies, using computerized image analysis, were carried out on microfocal x-ray images of skin sections whose blood system had been perfused in vivo with a radio-opaque medium. The analytical technique yielded information with regard to vessel number per wound and also the area occupied by blood vessels per unit wound area. Three regions were assessed in each wound bed: upper zone, just below the surface of the wound; the lower zone, just above the base of the wound bed; and the middle zone, midway between the other two zones. The results showed that the wounds maintained in a moist environment revascularized at a greater rate than those maintained in a dry environment. This was apparent in all of the zones of the wound bed examined. The development of new vessels occurred in a more orderly manner in the moist wounds. There was an early increase in vessel number rising to a peak around days 3-5, then a gradual decrease in number starting around day 7. In contrast, in the dry wounds the development of blood vessels was less rapid. Peak vessel number in the upper zone was significantly less than that achieved in the moist wounds, and was not reached until 7 d after injury. The decrease in vessel number from the peak was less rapid in the dry wounds, suggesting that there was a delayed entry into the remodeling phase in comparison with the moist wounds. The results also showed that the total percentage area of the wound bed occupied by blood vessels was greater in the moist wounds than the dry wounds from 3 d after injury until day 7. This level of vascularization was maintained beyond 7 d after injury even when the vessel number in the moist wounds was significantly less than in the dry wounds, suggesting that the vessels in the moist wounds were larger and, presumably, more mature. In general, moist wounds showed a more rapid decline towards uninjured skin levels of vascularization than dry wounds.
Animals↗
Relationship between joint space width and subchondral sclerosis in the osteoarthritic hand: a quantitative microfocal radiographic study.
Measurement of joint space width and subchondral sclerosis from x 5 macroradiographic examination of 32 patients with osteoarthritis (OA) of the hand over an 18-month period showed that joint space loss was symmetrical in both hands. Its change showed that over a period of time narrowing progressed proximally from distal interphalangeal to proximal interphalangeal, metacarpalphalangeal and wrist joints. Sclerosis was greatest in those joints at which the largest forces were exerted across the hand in precision, power and pulp-pinch grip, respectively. Our findings suggest that constitutional factors determine the onset of cartilage changes in OA which in turn result in subchondral sclerosis, the extent of which is determined by the pattern of normal forces within the hand.
Aged↗
Hypoprothrombinemia and hemorrhage in a surgical patient treated with cefotetan.
For 4 days before surgical repair of a diverticulitic colovesical fistula and for 6 days after, a 63-year-old man was treated with 2 g of intravenous cefotetan disodium every 12 hours for associated urosepsis with bacteremia. Postoperatively, the patient followed a diet of intravenous nutrition only. Uneventful convalescence was interrupted by signs of sudden major blood loss, accompanied by prolonged prothrombin time. After stabilization with packed red blood cells, fresh plasma, crystalloids, and parenteral vitamin K, laparotomy revealed a huge intra-abdominal clot, which was evacuated. This case illustrates the risk of unexpected hypoprothrombinemia and hemorrhage in a cefotetan-treated surgical patient who demonstrated none of the usual comorbid conditions generally described in patients with antibiotic-induced hypoprothrombinemia. Like cefamandole nafate, cefoperazone sodium, moxalactam disodium, and other cephalosporins containing the methylthiotetrazole side chain, cefotetan appears to pose an unusual risk of major bleeding.
Cefotetan↗
Techetium 99m methylene diphosphonate bone scanning in osteoarthritic hands.
In this prospective study, the radiological features characteristic of osteoarthritis of the hand were compared with the radionuclide bone scan images. A total of 32 patients was assessed at 6-monthly intervals for 18 months. Microfocal radiographs were taken at each visit. The high magnification and resolution of this technique permitted direct measurement of joint space width, subchondral sclerosis, osteophyte number and area and juxta-articular radiolucency area for each joint in the hand. Four-hour technetium 99m methylene diphosphonate bone scans were taken at 0 and 12 months and the activity of tracer uptake at each joint scored. The latter was compared with each X-radiographic feature at every visit and the changes between visits analysed. The scan scores did not correlate with any of the X-radiographic features other than osteophyte size. During the study the size of growing and remodelling osteophytes increased significantly at joints with raised or increased isotope uptake.
Female↗
Analysis of texture in macroradiographs of osteoarthritic knees using the fractal signature.
Texture of regions of macroradiographs (x5) of six normal and five osteoarthritic knee joints, taken on a high resolution microfocal x-ray unit, are examined using mathematical morphology. Radiographs of bones are two-dimensional projections of attenuation coefficient through the three-dimensional (3D) joint structure. Visible texture represents the summation of the attenuation from numerous thin plates of bone. Where there is no organization in the trabeculae, resultant radiographs approximate a fractal surface. Varying structuring element size in mathematical morphology allows estimation of fractal dimension over a range of resolution. Variation of fractal dimension with resolution, the fractal signature, indicates how images deviate from fractal surfaces. By correct choice of structuring element, a texture analysis method using the fractal signature has been developed, tolerant to changes in image acquisition and digitization. Texture in regions of radiographs of normal tibia approximates a fractal surface with dimension 2.8 as does vertical structure in arthritic patients. In osteoarthritic knee joints, horizontal tibial trabeculae thicken. Horizontal structure in the tibia on radiographs of arthritic patients deviates from the fractal model. This is indicated by peaks in the fractal signature whose height and position match a visual assessment of the degree of arthritic change.
Humans↗
Osteophytes in the osteoarthritic hand: their incidence, size, distribution, and progression.
Quantitative microfocal radiographic assessment of osteophytes in osteoarthritic hands showed that their number and area were greatest at joint margins, in the dominant hand, in the second and third compared with fourth and fifth phalanges, in the third phalanx, and in the second distal interphalangeal joint respectively. These sites correspond with those for the largest forces exerted in the hand: the dominant side, the finger tripod used in the precision grip, power grip, and pulp-pinch respectively. The greater osteophytosis on the trapezium of the nondominant first carpometacarpal joint was probably related to forces exerted during power grip. Osteophytes increased significantly in number and area during the 18 month study period.
Arthrography↗
Quantitative microfocal radiographic assessment of progression in osteoarthritis of the hand.
We studied 32 patients with osteoarthritis who had 5x macroradiographs taken of their wrists and hands at 6-month intervals over an 18-month period. The higher magnification and resolution of microfocal radiography permitted the quantitative detection of progressive changes in 4 different features: subchondral sclerosis, the number and size of osteophytes, juxtaarticular radiolucencies, and joint space narrowing. Compared with normal control subjects, subchondral cortical thickness was greater in all patients at entry and showed a variable degree of change over the study period. Osteophytes and juxtaarticular radiolucencies were present in all patients at study entry; by the end of the study, osteophytes had increased in number and area, and juxtaarticular radiolucencies had increased in area, but not in number. At entry, 44% of the patients had joint space narrowing significantly greater than that in the control subjects; by 18 months, this proportion increased to 65%. No correlation was found between subchondral sclerosis, osteophytes, juxtaarticular radiolucencies, and joint space narrowing. We conclude that in osteoarthritis of the hand, the bony changes have progressed significantly before the occurrence of radiographically evident joint space narrowing indicative of cartilage thinning.
Aged↗
Mechanical measures in the prophylaxis of postoperative thromboembolism in total knee arthroplasty.
Total knee arthroplasty patients are at high risk for deep venous thrombosis and pulmonary embolism. Prophylaxis against deep venous thrombosis and pulmonary embolism in these patients seems mandatory. Pharmacologic agents such as dextran 40, aspirin, and warfarin are effective but may be associated with significant complications such as drug reaction, bleeding, hematoma, and hemarthrosis. Heparin was not effective and was associated with significant bleeding complications. Mechanical methods such as continuous passive motion and sequential pneumatic compression stockings were without complications and seemed equal to or more effective than pharmacologic agents. Adding warfarin to mechanical methods did not seem to augment the antithromboembolic effect of the mechanical methods.
Anticoagulants↗
Hemoglobin C in association with hereditary persistence of fetal hemoglobin.
Hemoglobin C and hereditary persistence of fetal hemoglobin (HPFH) are an uncommon combination of hemoglobinopathies. Several tests are needed to verify this condition, among them hemoglobin electrophoresis and Kleihauer-Betke staining of a peripheral blood smear. Family studies are useful in delineating the genetics of the hemoglobinopathy but could not be performed in our case. In more confusing cases or with an unusual subtype, more extensive testing may be required. HPFH, by itself, is without clinical manifestations. It may be confused with other conditions; therefore, its presence in patients with hematologic symptoms requires more precise definition of the hemoglobin abnormality.
Adult↗
Distant nontraumatic clostridial myonecrosis and malignancy.
Distant nontraumatic clostridial myonecrosis in association with malignancy is an uncommon disorder, with only 14 well-documented cases previously reported in the English literature. Clostridium perfringens and C. septicum are the most common organisms, usually gaining access to the circulation through an ulcerated lesion of the small bowel or colon. A case report of this syndrome caused by C. histolyticum is presented with a review of the literature.
Adenocarcinoma↗
Mycetoma-like granuloma in a cat caused by Microsporum canis.
A solitary subcutaneous nodule from a Persian cat consisted of coalescing mycetoma-like granulomas containing abnormal hyphae of Microsporum canis. Overlying hair follicles were heavily laden with dermatophytes but had little associated perifollicular inflammation. The complex classification of dermatophyte-induced dermal inflammatory lesions is reviewed.
Animals↗
Developmental changes of oculomotor characteristics in infants when awake and in the 'active state of sleep'.
Since the principal criterion for identifying sleep in the young infant is eye closure, a study was undertaken to ascertain whether fast or 'saccadic-type' movements which occur in the eyes-closed condition differ in any respect from those which are observed in the eyes-open (awake) state. Specific parameters included the amplitude-velocity relationship, the numbers and types of non-conjugate movements (disjunctive and monocular), directionality and densities (EM/min). Measurements were made on 12 infants at 4-week intervals as they progressed in age from 4 weeks to 12 weeks. The results disclosed that in the main as the infants developed, a change, if any, of ocular characteristic in the awake state was paralleled by a similar change in the eyes-closed state, although the absolute number of eye movements was higher in the eyes-open state compared to the eyes-closed state. This suggests that the eye movement characteristics, whether the eyes were open or shut, were dictated primarily by oculomotor development and the mechanics of eye closure rather than by different mechanisms of neural control effected through different states of consciousness. Of special interest was the finding that the velocity-amplitude relationship in the infant's eyes-open state was almost identical to that reported for adults in the eyes-open state whereas the value for the eyes-closed state was comparable to that of the adult's eyes-closed awake state rather than to the value obtained for adults in REM sleep.
Aging↗
Central nervous system lesions in suckling mice and rats inoculated intranasally with sialodacryoadenitis virus.
Suckling CD-1 and CFW mice and WI Wistar rats were inoculated intranasally with sialodacryoadenitis virus. In animals inoculated during the first week of life, there was an acute necrotizing encephalitis with malacia and minimal inflammatory cell response. In mice and rats which survived for up to 12 days post inoculation, loss of brain substance, gitter cells and occasionally mineralized debris were seen. Viral antigen was readily demonstrated in neurons and nasal epithelium in trypsin-treated, paraffin-embedded sections, and corresponded with the presence of lesions. There was no compelling evidence that sialodacryoadenitis virus invaded the central nervous system directly via the cribriform plate, and hematogenous spread was considered to be a likely route of spread to the brain. An age-related resistance to the encephalitic form was evident beginning at 10 days of age in both species. Thus it is conceivable that encephalitis could occur in young suckling rats exposed during naturally-occurring epizootics of sialodacryoadenitis.
Animals↗
Application of a modified indirect fluorescent antibody test to the detection of antibodies to bovine respiratory syncytial virus in Ontario cattle.
A modified indirect fluorescent antibody test for the detection of serum antibodies to bovine respiratory syncytial virus was developed. The test made use of Terasaki plastic microtiter plates in which bovine respiratory syncytial virus (Saskatchewan strain) infected Georgia bovine kidney cells were grown and fixed in situ by a modified acetone fixation procedure. Evans blue dye was used as a counterstain to reduce nonspecific fluorescence. In a study of 986 field sera from a geographically broad cross-section of mature Ontario cattle, 95% of the samples were found to be positive at or above a 1:2 dilution. No seronegative regions, counties or herds were identified. When representative samples covering a range of indirect fluorescent antibody titers were further examined by a microtiter virus neutralization assay, a significant agreement was found between the two tests. Up to a fourfold decrease in titer was observed when antigen coated plates were stored at -70 degrees C for four months. The modified indirect fluorescent antibody test for bovine respiratory syncytial virus antibody detection proved to be a rapid, practical procedure for use in the diagnostic laboratory. This study confirms that bovine respiratory syncytial virus is widespread in the Ontario cattle population and that most mature cattle can be assumed to have been exposed to this virus.
Animals↗
California serogroup virus infection in a horse with encephalitis.
A 4-fold or greater seroconversion to the snowshoe hare serotype of the California serogroup of viruses in a horse with acute encephalitis was demonstrated by hemagglutination-inhibition, complement-fixation, and neutralization tests. The horse had a mild fever, was ataxic, had a head tilt, and was observed to circle. Chloramphenicol, dexamethasone, and B complex vitamins were administered and the horse recovered. The snowshoe hare virus is a recognized human pathogen, but it has not been associated with disease in horses. It is unknown whether horses play a role as amplification hosts for the snowshoe hare virus in nature, and further studies appear indicated.
Animals↗
Comparison of eye motion in wakefulness and REM sleep.
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Darkness↗
The influence of fibroblast-like cells derived from canine fetal hematopoietic tissues on the regulation of lymphohematopoiesis.
Media conditioned by fibroblast-like cells derived from organs active in fetal lymphohematopoiesis were studied for their effects on adult granulocyte/macrophage colony-forming units (CFU-GM). Fibroblasts from fetal liver produced a factor stimulatory for CFU-GM, whereas fibroblasts from fetal marrow produced a factor inhibitory for CFU-GM which was not completely relieved by adding indomethacin to the assay. Our studies indicated that neither fetal marrow nor fetal liver produced factors affecting lymphocyte colony-forming units (CFU-L). Cell-cell interactions between fibroblast-like cells derived from fetal liver or marrow and normal adult CFU-GM were also studied. We observed that fibroblasts derived from both fetal and adult marrow inhibited colony formation, whereas inhibition in the presence of fetal liver fibroblasts was minimal. Loss of inhibitory activity by a liver fibroblast cell line over repeated passages was seen. Differential analysis of colonies formed above an adherent layer of fetal marrow fibroblasts suggested that these fibroblasts suppress myeloid/macrophage differentiation to a far greater degree than did adult marrow fibroblasts. A role in the regulation of fetal lymphohematopoiesis may be played by stromal fibroblasts.
Animals↗