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Biomedical subjects

S Nade

Publications and source records attributed to S Nade.

At least 37 records · Page 2Linked to original sources
PubMed1987

Growth of bone marrow cells on porous ceramics in vitro.

Following the transplantation of bone marrow cells to extra-osseous sites, bone formation occurs in those sites. This osteogenic potential of bone marrow cells might be utilized for filling defects in bone if they could be transported on porous ceramic materials. Before such an approach becomes feasible, it is important to know what happens to the cells in the presence of the ceramics that might be used. In order to investigate the interaction between bone marrow cells and ceramics, in vitro, a system for culturing bone marrow cells on ceramic materials has been developed. Bone marrow cells adhered well to the surface of calcium hydroxyapatite and tricalcium phosphate ceramics, and this was followed by the formation of fibrous tissue on and within the ceramics. These ceramics were compatible with bone marrow cells even in culture conditions in which there was a large surface area of ceramic interfacing with cells. The results support the proposal that calcium hydroxyapatite and tricalcium phosphate are appropriate as bone replacement materials. In contrast, calcium aluminate had an adverse effect on bone marrow cells when there was a high proportion of ceramic to culture medium. However, this effect was not present if the proportion of ceramic to culture medium was low. Therefore, a large amount of biodegradable porous calcium aluminate ceramic should not be used as an alternative to autogeneous bone grafting.

Aluminum↗
PubMed1987

Natural history of acute septic arthritis in an avian model.

An experimental model of acute septic arthritis is described, utilizing the injection of S. aureus into chicken hock joints. The course of the infection was monitored over a 14-day period by measurement of chicken growth rate, histopathology of the joint, number of bacteria, and number and type of leukocytes in the synovial fluid. Bacterial numbers decreased initially then increased rapidly over the first 24 h. Leukocyte counts rose sharply, starting between 60 and 90 min after injection. Gross destruction of articular cartilage was observed at 4 days, and appeared to be initiated by the adherence of the staphylococci to the cartilage surface followed by their penetration and invasion of vascular tunnels in the epiphyseal cartilage. Extensive (but focal) erosion of the articular surface was evident by 14 days.

Animals↗
PubMed1987

Pseudomonas osteomyelitis of the spine. Report of a case not associated with drug abuse.

Pseudomonas aeruginosa, as a cause of vertebral osteomyelitis, has previously been described as occurring in drug abusers. Various empirical methods of treatment have been employed without good follow-up studies. This case report provides a radiological and clinical evolution of pseudomonas vertebral osteomyelitis together with a successful treatment regimen in a 73 year old man who had spontaneous onset of the disease.

Aged↗
PubMed1987

The effects of direction and acceleration of movement of the knee joint of the dog on medial articular nerve discharge.

1. The normal activity of the medial articular nerve of the knee joint of nine dogs was measured in response to continuous passive movement. Whole nerve recordings were made simultaneously with joint position and angular velocity. 2. When the knee was moved the medial articular nerve discharged at all joint angles with maximum activity at flexion in some animals, and at extension in others. For an individual animal the discharge pattern was reproducible over several cycles of movement. 3. The discharge was direction sensitive, responding with a lesser activity whenever the joint was moved away from the extremes of movement range. 4. With higher velocities of movement, the discharge activity of the nerve increased at the ends of joint movement. 5. The results indicate that the discharge activity of the whole medial articular nerve is influenced not only by joint position but also by the velocity and acceleration of movement. This may reflect changes in the tension of capsular and extra-capsular tissues.

Action Potentials↗
PubMed1987

Staphylococcal adherence to chicken cartilage.

Immature chicken cartilage was incubated in a Staphylococcus aureus suspension and then washed. Scanning electron microscopy and radiolabel measurements showed increased adherence to cartilage with increasing bacterial concentration. Preheating of the bacteria did not reduce the adherence property, but trypsin treatment did.

Animals↗
PubMed1986

The interrelation of neural discharge, intra-articular pressure, and joint angle in the knee of the dog.

Single- and multi-unit recordings were obtained from the medial articular nerve (m.a.n.) of knee joints in the anaesthetized dog. The single-unit recordings were confined to low threshold (group I and II) articular mechanoreceptors. Multi-unit recordings revealed that the m.a.n. discharge was maximal in extension, submaximal in flexion, and minimal at intermediate angles, i.e. a U-shaped profile. Subatmospheric intra-articular pressures do not appear to influence the m.a.n. discharge. Intra-articular infusion of even small quantities of fluid, although not affecting the U-shaped profile, reversed the m.a.n. discharge pattern with maximum neural activity occurring in flexion and being submaximal in extension. Recordings from single units indicated that the enhanced discharge after fluid infusion was a result of increased discharge frequency and 'recruitment' of individual afferents.

Action Potentials↗
PubMed1986

Acute haematogenous osteomyelitis and septic arthritis--a single disease. An hypothesis based upon the presence of transphyseal blood vessels.

The acute childhood diseases haematogenous staphylococcal osteomyelitis and septic arthritis were studied concurrently using avian models which closely resemble the human diseases. Ultrastructural studies during the initial stages of bone and joint infection showed that adherence of bacteria to cartilage, bacterial proliferation, cartilage destruction and subsequent bacterial spread along the vascular channels within cartilage were common to both disease processes. Histological studies revealed that transphyseal blood vessels were present in the growing chickens and were a likely explanation for the frequency of the concurrence of acute osteomyelitis and adjacent joint infection following intravenous injection of bacteria. Transphyseal vessels provide a direct connection between the growth plate (physis) and epiphyseal cartilage supplying a route for bacteria to spread from an osteomyelitic focus in the metaphysis to the epiphysis and subsequently to the joint lumen.

Animals↗
PubMed1986

Acute hematogenous staphylococcal osteomyelitis: the effects of surgical drilling and curettage in an animal model.

Surgical drilling and curettage of metaphyseal medullary bone were performed in chickens 4, 8 and 15 d after bacterial inoculation with Staphylococcus aureus producing osteomyelitis. Intramedullary drilling and curettage resulted in extensive vascular damage and necrosis of medullary bone but failed to remove all viable bacteria. An effective continuing drainage channel for the pus was not established due to the formation of blood clot within the drill hole. Surgery performed before the formation of a sequestrum resulted in further spread of bacteria within the medullary cavity and the formation of a larger sequestrum than that commonly observed in the bones of infected, untreated chickens. Surgery performed after the formation of a sequestrum destroyed the abscess wall thus disrupting a natural defence mechanism of the host. Whilst a direct comparison of surgical drilling in human osteomyelitis and in this avian model cannot be made, the results suggest that production of an artificial drill hole across the cortex and curettage of the bone in human osteomyelitis would be destructive and may not be warranted.

Acute Disease↗
PubMed1986

Transphyseal blood vessels exist in avian species.

The distal femora and proximal and distal tibiae of 4 weeks old broiler chickens have three main types of blood vessels in the growth plate region-metaphyseal, epiphyseal and transphyseal. The transphyseal vessels extend across the entire thickness of the avian growth plate and provide a means of luminal communication between the metaphysis and epiphysis.

Animals↗
PubMed1986

Hereditary bone dysplasia with malignant change. Report of three families.

In this paper three families are reported with members who had hereditary bone dysplasia that was originally described by Arnold in one family. We provide further information about that family and suggest that the diagnosis of the malignant change should be changed from fibrosarcoma to malignant fibrous histiocytoma. A thorough search of the literature has failed to reveal any conditions, either hereditary or acquired, that are similar. The major feature of the dysplasia is diaphyseal medullary stenosis of bone with overlying cortical-bone thickening, and the propensity to malignant transformation and fractures with minimum trauma is emphasized. The tumors in seven, and possibly eight, of the nine patients in whom a malignant lesion developed were originally classified as fibrosarcoma and proved to be markedly aggressive. The hereditary pattern appears to be autosomal dominant. The clinical manifestations of a malignant lesion occur generally in the second to the fifth decades of life.

Adolescent↗
PubMed1985

Bone ingrowth into three different porous ceramics implanted into the tibia of rats and rabbits.

Three different porous ceramics--calcium aluminate, calcium hydroxyapatite, and tricalcium phosphate--were implanted into the proximal tibia in rats and rabbits to study the interactions between these ceramics and a bony site that is abundant in bone marrow. New bone was consistently formed within the bone marrow surrounding and adjacent to all three types of ceramics. Calcium hydroxyapatite and tricalcium phosphate ceramics permitted bone ingrowth into their pores. The newly formed bone was found only in the part of the ceramic intruding into the bone, not in the portion protruding in the soft tissues outside the tibia. Partial replacement of the new bone opposite the medullary portion by new hemopoietic marrow occurred with longer implantation times. In contrast, no bone was seen within the pores of any of the calcium aluminate implants.

Aluminum↗
PubMed1985

The significance of the Trendelenburg test.

Trendelenburg's test of function of the hip joint was first reported before radiology was available. At least four methods of performing it have since been described in the literature. We examined 50 normal subjects and 103 people with disorders affecting either the spine or the hip, in order to determine the different responses that occurred when they were asked to stand on one leg. This has enabled us to define a standard method of performing the Trendelenburg test, and to interpret the test as a method of assessing hip abductor function. The major pitfalls that result in misinterpretation, or false-positive responses, are pain, lack of cooperation from the patient, and impingement between the rib cage and the iliac crest. False-negative responses result from the patient using muscles above and below the pelvis, and from leaning beyond the hip on the standing side.

Adolescent↗
PubMed1984

Pressure-volume relationships and elastance in the knee joint of the dog.

This study has investigated changes in intra-articular hydrostatic pressure in the knee joints of normal dogs in response to continuous and stepwise infusions of fluids. The relationship between pressure and volume in the joint was examined over the pressure range of -8 to +50 mmHg, and also at much higher pressures often associated with joint disease or injury. The effects of joint angle and dog weight on the pressure-volume relationship and on elastance of the dogs' knees were also examined. With liquid paraffin B.P. the pressure was found to increase more with each unit volume infused at subatmospheric pressures than at pressures around atmospheric, and increased more again at higher pressures. The pressure-volume curve with saline infusions was affected by egress of fluid from the joint at supra-atmospheric pressure. Above +5 mmHg the rise in pressure per unit volume infused was less than that for paraffin at the same volume. Elastance and compliance of the normal joint capsule were calculated from the pressure-volume data. Elastance was high at subatmospheric pressures, decreased rapidly as atmospheric pressure was approached and rose as a linear function of pressure above 12 mmHg. The biphasic shape of the elastance-pressure curve is discussed, and explanations for the shape are suggested. After intra-articular pressure in the knee was raised by infusion of paraffin oil the joint was moved through the range of positions from 125 deg extension to 50 deg flexion. Intra-articular pressure did not change across the range 125-110 deg. However, increasing the angle of flexion from 110 to 50 deg resulted in a rise in pressure which became steeper for each volume increment. Increasing intra-articular fluid volume caused a decrease in the total range of movement of the joint. The pressure-volume curves measured at extended angles of 110, 125 and 140 deg, where the starting pressures were subatmospheric, were the same. At flexed joint positions of 80 and 50 deg, where the starting pressures were supra-atmospheric, the pressure-volume curves became steeper with greater flexion. Elastance of the joint tissues increased with flexion. The elastance at each joint angle depended also on the volume or pressure. Significant differences were found to exist between pressure-volume curves for three groups of animals of different weight.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Acute hematogenous staphylococcal osteomyelitis: evaluation of cloxacillin therapy in an animal model.

A reproducible avian model of acute hematogenous staphylococcal osteomyelitis was used to investigate various aspects of antibiotic therapy using a single antibiotic, cloxacillin. The effects of both delaying antibiotic administration and increasing the frequency of antibiotic administration on the outcome of the disease were evaluated. Following bacterial inoculation, a delay in commencing therapy for 4 d in comparison to 1 d significantly reduced the likelihood of a favourable outcome. An increase in the frequency of antibiotic administration from once to 4 times daily resulted in significant improvement in the recovery rate of chickens. Whilst repeated antibiotic administration controlled the systemic effects of the disease and improved the clinical status of chickens, the local bone lesion was not always sterilized. The role of antibiotic therapy in acute hematogenous osteomyelitis is discussed in relation to these findings.

Animals↗
PubMed1984

Pain in the leg: an overview.

Pain in the leg has many causes but a clinical diagnosis usually can be determined by attention to detail. A schematic approach is presented with critical questions to be asked of the patient; flow charts assist the diagnosis.

Acute Disease↗