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Biomedical subjects

I Ziv

Publications and source records attributed to I Ziv.

At least 109 records · Page 6Linked to original sources
PubMed1988

Cultured human bone marrow-derived mast cells, their similarities to cultured murine E-mast cells.

Homogeneous populations of human mast cells were differentiated and grown by culturing bone marrow cells in the presence of conditioned medium derived from lectin-stimulated human peripheral blood mononuclear cells. The cells obtained were similar in ultrastructure, proteoglycan type and lipid products generated upon calcium ionophore A23187, and immunological activation to the murine E-mast cells (E-MC) differentiated in culture containing IL-3. Fluorescence analysis revealed that the human E-MC expressed IgE-Fc receptors which retained bound IgE through several washes. These cells did not express cell-surface lymphoid determinants (T11, T4, T8 and B4) and myeloid determinants 'My'. However, 40% of these cells expressed monocytic surface determinants, such as M-1. The amount of histamine that was found per 10(6) cells was 525 +/- 106 ng (mean +/- SE, n = 4). These cultured mast cells possessed granular chondroitin sulphate E proteoglycan of about 180,000 MW. Following activation with either calcium ionophore A23187 or anti-hIgE challenge, these mast cells released their preformed mediators and generated mainly leukotriene C4 leukotriene B4, and platelet-activating factor. In conclusion, according to all of these criteria, these human cultured mast cells show many similarities to the murine cultured E-mast cells, and therefore could be considered as the culture analogue of the human intestinal E-mast cells identified recently.

Adult↗
PubMed1988

Osteogenesis in in vivo diffusion chamber cultures of human marrow cells.

The osteogenic diffusion chamber culture of rodent marrow cells is a well established system. In the present study, marrow cells from children and adult human donors were incubated in diffusion chambers implanted intraperitoneally in athymic mice. After 4 or 8 weeks, the chamber content was examined by light and electron microscopy. Child-cell cultures showed osteogenic tissue consisting of a mineralizing fibrous component and cartilage. Ultrastructurally, the fibrous tissue was similar to osteoid and exhibited osteoblast-like cells and mineralizing nodules. Mineral aggregates were also found in the cartilage. These features in child-cell chambers were similar to those found in control chambers of rabbit marrow cells. Adult-cell chambers showed only unmineralized fibrous tissue. These results render previous findings in animal-cell diffusion chamber systems relevant to the understanding of bone formation in man. It is suggested that the difference between child- and adult-cell chambers reflects an age-related decline in the number of marrow osteoprogenitor cells or their potential to undergo terminal osteogenic differentiation.

Adult↗
PubMed1987

Unusual combination of Monteggia, Colles', and navicular fractures.

A rare combination of an ulnar fracture with posterior dislocation of the head of the radius and intraarticular fracture of the distal radius concomitant with an ipsilateral navicular fracture is presented. To the best of our knowledge, no such case has been reported. The mechanism of this fracture combination is discussed with respect to its role in producing the Monteggia type II fracture. Treatment consisted of a combination of closed and open reduction with external fixation.

Adult↗
PubMed1987

Spondylolysis in the upper lumbar spine. A study of 32 patients.

Reports of spondylolysis in vertebrae other than those of the lower lumbar spine are rare. We report 32 patients with upper lumbar spondylolysis who have been studied clinically, radiologically and scintigraphically. Twenty patients had bilateral lesions, and seven of those with unilateral lesions had structural changes or anomalies in the opposite posterior arch. Positive scans were found to be associated with a short clinical history, and indicated stress-related lesions. Our findings suggest that mechanical factors may play a role in the aetiology of spondylolysis in the upper lumbar spine similar to that which they play in the lower lumbar spine, and that local structural anomalies may contribute to abnormal loading of these vertebrae.

Adolescent↗
PubMed1986

The "instantaneous" deformation of cartilage: effects of collagen fiber orientation and osmotic stress.

The present study was undertaken with two objectives in view. The first was to distinguish between the "instantaneous" deformation and creep of articular cartilage when subjected to a step loading in unconfined compression. This was done by observing changes in the specimen's diameter rather than its thickness. The second objective was to investigate experimentally the anisotropic behaviour of cartilage in a compressive loading mode, corresponding to the physiological situation. An apparatus was thus developed and constructed which enabled us to follow the "instantaneous" changes of the surface area of the sample as the latter was being loaded in unconfined compression. Specimens of human articular cartilage from normal femoral heads and condyles were tested. Full thickness specimens were tested with and without the underlying bone, as well as partial thickness specimens, characterizing the different zones of cartilage. Solutions of different ionic strength were used to vary the osmotic stress and specimens covering a considerable range of proteoglycan concentrations were selected. The effects of hydration and proteoglycan removal on the "instantaneous" deformation were also studied. The "instantaneous" deformation was found to be of a strongly anisotropic nature in all zones. The deformation was always smaller along the Indian-ink prick pattern than at 90 degrees to it, and this effect was most pronounced in the superficial zone of cartilage. The results reveal an analogy with the tensile properties of cartilage and indicate that the collagen network is mainly responsible for controlling the "instantaneous" deformation. The proteoglycans play an indirect role by modulating the stiffness of the collagen network through their osmotic pressure.

Aged↗
PubMed1985

Roll-over test--errors in interpretation, due to inaccurate blood pressure measurements.

In order to make the earliest possible prediction of the type of woman likely to develop pregnancy-induced hypertension (PIH), one hundred and ninety-six primigravidas underwent a roll-over test (ROT) during wk 28-32 of their pregnancy. Blood pressure (BP) readings were taken with a standard 12 cm cuff as well as with cuffs adapted to various arm circumferences. We found that the prediction rate of ROT readings with a standard 12 cm cuff was relatively low (38.5%) as compared with Gant's study (94%) (Amer. J. Obstet. Gynec., 120 (1974) 1). When a suitably sized cuff was used, the prediction rate dropped (to 14.7%). Data analysis at term for the whole population of this study shows that, by measuring with a standard 12 cm cuff, 10.2% of the women were found to have PIH, whereas measuring with a suitable cuff showed PIH in only 2.55% of the cases (1:4 ratio). We suggest that the low prediction rates in this and other studies demonstrate that the ROT test is not sufficiently reliable as a tool for predicting which women are liable to develop PIH, but there is definitely enough in it to predict which group will not develop PIH (in this study 89-93%). It has been recommended that ROT be considered only as a test of possible reliability. It should be done according to proper criteria for BP measuring, and a repeat ROT should be considered after several days before starting any kind of treatment.

Adolescent↗
PubMed1985

Studies of hydration and swelling pressure in normal and osteoarthritic cartilage.

An experimental study was carried out which involved comparing cartilage from normal and osteoarthritic joints with respect to (a) swelling pressure and (b) variation of hydration with applied pressure. The main conclusion was that whilst osteoarthritic cartilage is undoubtedly less able to resist water loss under a given applied pressure than normal cartilage, this is not due to a change in the "quality" of the proteoglycans, resulting in a change in the osmotic pressure of the latter, but simply to a decreased fixed charge density. The latter decrease is either caused by an increase in the water content - and this we attribute to a weakened collagen network - and/or to a loss of part of the proteoglycans from the tissue.

Aged↗
PubMed1984

Femoral intramedullary nailing in the growing child.

The outcome of intramedullary nailing in 17 femoral fractures was studied in children aged 5 to 12 years. By this age independent vascularity of the capital femoral epiphysis has become established. Indications were: severely displaced diaphyseal fractures uncontrolled by closed reduction in patients with head injury or multiple trauma. All were treated by open reduction and retrograde nailing using Rush pins or Kuntscher nails. All children became community ambulators and were followed until maturity. There were no significant rotational deformities and leg length discrepancy due to overgrowth was less than 1.0 cm at termination of growth. Growth arrest of the greater trochanter was seen in three hips that were reamed for Kuntscher nailing but in none of those fixed with Rush pins. Retrograde Rush pinning appears to be a safe and effective procedure that avoids insult to the proximal femoral blood supply. Growth plate changes did not significantly affect hip function.

Bone Nails↗
PubMed1984

Muscle growth in normal and spastic mice.

Longitudinal muscle growth was studied in normal and spastic mice. Muscle growth takes place at the musculotendinous junction--the 'muscle growth-plate'. In spastic mice muscle growth is reduced by 45 per cent, resulting in contractures.

Animals↗
PubMed1984

Correction of the malunited forearm fracture.

Malunion of a child's forearm fracture is a functional and cosmetic disability. Drill osteoclasis is an alternative to open osteotomy. Fifteen consecutive cases demonstrate the following advantages of the technique: (1) the absence of an unsightly scar, (2) full, reliable correction of the deformity, (3) no need for a second operation to remove a plate, and (4) no risk of fracture occurring subsequently through a screw hole.

Bone and Bones↗
PubMed1983

Paraplegia in osteogenesis imperfecta. A case report.

Paraplegia occurred in an adolescent girl with osteogenesis imperfecta after chiropractic manipulation. The child had been able to walk freely out of doors. Complete motor paralysis with sensory sparing resulted due to anterior compression of the cord by spondyloptotic cervical vertebrae. Reconstructed computerised tomography was very helpful in demonstrating the abnormality. Anterior and then posterior decompression relieved the tethered spinal cord and were supplemented with bone grafting. Early diagnosis and surgical treatment will prevent similar neurological accidents.

Child↗
PubMed1983

Treatment of femoral fracture in the child with head injury.

The outcome of various types of treatment for femoral fracture in children with head injury was studied retrospectively in 51 patients with 56 fractures. Of these, 36 patients (71 per cent) were in deep coma and scored 5 to 7 on the Glasgow scale. Forty-three children (84 per cent) were eventually able to walk freely. Open reduction and internal fixation proved an attractive solution for femoral fractures in children with head injury who could tolerate general anaesthesia: intramedullary nailing was safe and gave satisfactory results in 16 fractures but infection complicated three of the five fractures which were plated.

Bone Plates↗
PubMed1982

The importance of cuff width in measurement of blood pressure in pregnancy.

Blood pressure was measured indirectly in 218 normotensive primigravidas with arm circumferences ranging from 21.7 to 36.1 cm using three standard blood pressure cuffs. It was found that the medical profession's lack of awareness as to the proper use of cuffs in prenatal care may involve 40% of the patients--20% of these have a small arm circumference, will not show a true blood pressure reading, and may fail to get the proper treatment. On the other hand, 20% of these patients who have a rather large arm circumference, may be grouped among those who need special care and attention, and may be given unnecessary treatment--a fact which may bring about clinical complications, unnecessary expense, incorrect statistical data and a misleading demographic impact.

Adolescent↗
PubMed1982

The role of arthroscopy in children.

The records for 156 consecutive arthroscopic examinations in children with knee complaints were reviewed. Diagnostic accuracy was based on subsequent arthrotomy and the clinical course in the absence of arthrotomy. All arthroscopies were performed by one person (NCC) between 1975 and 1979. Children under 12 years (most of them aged 6-11 years) accounted for 43 of the patients. The arthroscopic diagnoses were classified into three categories: very useful, useful, and not useful. Arthroscopy was found to be very useful in 30% of children in both age groups, those under and those over 12 years. In all these patients, unnecessary arthrotomies were avoided. Most (63%) of the arthroscopies were found to be useful, since they provided additional findings and biopsies. Only in 5% of cases did the arthroscopy fail to add any information. There were no complications from the procedure. Arthroscopy is an effective diagnostic tool that can be used safely in children.

Adolescent↗
PubMed1979

Orthotopic bone transplantation in mice. I. Technique and assessment of healing.

A technique for orthotopic bone transplantation in mice has been developed. A section of recipient tibia was removed and replaced by a similar section from the donor animal. The graft was held in place by internal fixation. Bone healing was assessed clinically, histologically, radiologically, and by torsion testing. The most objective measurements of bone healing were the maximum torque and the energy absorbed by the bone to failure, which were derived from torsion testing. The degree of bone healing in donor-recipient combinations differing at H-2, non-H-2, or H-Y antigens was compared to the degree of healing in syngeneic controls. The incidence of nonunion was significantly increased in the H-2-disparate group. Furthermore, the extent of bone healing as measured by torsion testing was significantly reduced in both the H-2-and the H-Y-disparate groups. Thus, in the strain combinations tested, the order of importance of the genetic disparities influencing allogeneic bone grafts was H-2 greater than H-Y greater than non-H-2. The impaired healing of allogeneic bone grafts was probably immunologically mediated, as suggested by the observation that recipients of bone allografts rejected subsequent skin allografts in an accelerated manner.

Animals↗