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Biomedical subjects

G Robin

Publications and source records attributed to G Robin.

At least 37 records · Page 2Linked to original sources
PubMed1993

Human facet cartilage: swelling and some physicochemical characteristics as a function of age. Part 2: Age changes in some biophysical parameters of human facet joint cartilage.

This study was aimed at investigating, in relating to aging, some of the biochemical and biophysical characteristics of the facet cartilage that determine the functional behavior of this tissue. In addition, facets and discs from the same segment were graded according to their macroscopic appearance. The proportion of severely degenerate discs was low in young subjects and increased with age; by contrast, the proportion of coarsely fibrillated and/or ulcerated facets was high in spines from young adults and remained constant throughout adulthood. Unlike discs, facets do not show an age-related loss of proteoglycans or a consequent decrease in the resistance to a compressive load. However, even in relatively young age groups (30-50 years) a high hydration was observed more often in facet joints than in cartilage from other joints studied. These characteristics are known to accompany damage of the collagen network and cartilage degeneration. Unlike normal femoral head cartilage, facet cartilage does not show a rise in fixed charge density with age. The cartilage from the superior processes (concave) is thicker than that from the inferior processes (convex) and has a higher fixed charge density. At the same time it has a higher water content, which indicates that damage occurs more frequently.

Adolescent↗
PubMed1993

Immunogenicity and efficacy of oral or intranasal Shigella flexneri 2a and Shigella sonnei proteosome-lipopolysaccharide vaccines in animal models.

Immunity against shigellosis has been shown to correlate with the presence of antibodies specific for Shigella lipopolysaccharide (LPS). We here propose a new candidate vaccine for shigellosis composed of purified Shigella flexneri 2a or Shigella sonnei LPS hydrophobically complexed with group C type 2b Neisseria meningitidis outer membrane protein proteosomes. Immunization of mice either orally or intranasally with this complex induced specific homologous anti-LPS antibodies in both intestinal and respiratory secretions as well as in sera. Strong anamnestic responses were found after two or three immunizations. LPS alone, alkaline-detoxified LPS, or alkaline-detoxified LPS complexed with proteosomes was not effective. Oral or intranasal immunization of guinea pigs with two or more doses of this proteosome-LPS vaccine elicited homologous protection against Shigella keratoconjunctivitis (Serény test). These data demonstrate that proteosomes can be used as an effective mucosal vaccine delivery system and that orally or intranasally administered acellular vaccines can protect against Shigella infections.

Administration, Intranasal↗
PubMed1992

Presence of specific immunoglobulin A-secreting cells in peripheral blood after natural infection with Shigella sonnei.

The appearance of antigen-specific immunoglobulin A (IgA) antibody-secreting cells (ASCs) following natural infection with Shigella sonnei during a common-source outbreak caused by this organism was evaluated in a modified enzyme-linked immunosorbent assay (ELISPOT). A mean IgA ASC value of 2,131.6/10(6) cells against homologous S. sonnei lipopolysaccharide (LPS) was detected in blood samples obtained from patients with bacteriologically proven S. sonnei shigellosis 5 and 10 days after the onset of disease. In the same blood samples, the level of ASC measured against heterologous antigen (Shigella flexneri serotype 2a LPS) was significantly lower than that of the homologous antigen (mean value, 33.12/10(6) cells). Furthermore, the mean number of activated B cells that secreted anti-S. sonnei LPS antibodies was significantly higher among patients with S. sonnei shigellosis than it was among patients with non-Shigella diarrhea (2.5/10(6) cells; standard error, 1.0) and healthy subjects (5.1/10(6) cells; standard error, 2.3) (P less than 0.05). The anti-LPS IgA ASC activity was easily detected within 5 days of the onset of disease, a point at which the levels of anti-S. sonnei LPS IgG and even IgA antibodies were hardly detectable in serum.

Adolescent↗
PubMed1991

Human recombinant granulocyte-macrophage colony-stimulating factor augments viability and cytotoxic activities of human monocyte-derived macrophages in long-term cultures.

In the present study we investigated the effect of human recombinant granulocyte-macrophage CSF (GM-CSF) on the in vitro maturation of human monocytes into macrophages, and followed the biochemical and functional changes in the cells during this process. Adherent human peripheral blood monocytes cultured for up to 3 weeks in the presence of GM-CSF were examined for viability and adherence, beta-glucosaminidase activity, oxidative burst activity, expression of fucosyl-mannosyl receptors, and TNF-alpha production. The cultured monocytes increased in size and protein content and matured into macrophages within 12 to 18 days. GM-CSF treatment increased by 2.5-fold the number of adherent cells after 2 weeks in culture, but did not change the beta-glucosaminidase and oxidative burst activities of the cells compared to nontreated controls. GM-CSF increased the capacity of monocyte-derived macrophages to bind yeasts and bacteria via fucosyl-mannosyl receptors, by both augmenting the viability of the adherent cell population and by elevating the expression of such receptors per cell. GM-CSF-treated macrophage cultures also showed elevated production of TNF-alpha. The results described here showed that GM-CSF facilitated the long-term maturation of monocytes into macrophages, augmented their capacity to capture bacterial and fungal cells, and elevated the release of cytokines involved in inflammatory and granulomatous reactions.

Bacterial Adhesion↗
PubMed1990

Experimental stress fractures of the tibia. Biological and mechanical aetiology in rabbits.

We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures.

Animals↗
PubMed1989

[Cauda equina syndrome in lumbar disc herniation].

During the past 5 years 10 patients suffering from cauda equina syndrome as a result of prolapsed disc were treated surgically. Although considerable time had elapsed between the onset of symptoms and the operation, most of the patients improved, at least partially. The syndrome is a rare complication of a common condition of the lower spine. Awareness of its possibility and identification of the early clinical picture are essential. An accurate history and detailed physical examination are the most important factors in early diagnosis. In 5 women and 4 men, who ranged in age from 28-60 and averaged 41 years, the disks involved were L5-S1 in 6, L4-L5 in 2 and L1-T12 in 1 case. Persistent disability was found in most of the patients, including 4 with bladder and 4 with sexual dysfunction. In 7 there was residual sensory loss and in 5 some degree of motor weakness. Earlier surgical treatment seems to be the most effective method for improving the results of treatment.

Adult↗
PubMed1987

Growth rate analysis of lung metastases from histologically benign giant cell tumor of bone.

A growth rate analysis of lung metastases of benign giant cell tumor (GCT) of bone, histologically indistinguishable from the primary benign tumor, is presented. The doubling time (DT) was 186 days in the first 13 months of growth, and 465 days in the last 4 months. These DTs are much longer than DT of lung metastases of any other tumors, and have a good correlation with a long survival time. Backward extrapolation showed that the lung metastases began to develop years before the primary tumor was diagnosed and treated. If this can be confirmed in a larger number of patients, it could be concluded that there will be no indication for amputation as a treatment for benign GCT whether or not lung metastases are present. The growth rate analysis supports the concept that these metastases might represent a benign process, and as such are a unique histologic and clinical phenomenon.

Adult↗
PubMed1982

Anterior decompression of the spine for metastatic epidural cord compression: a promising avenue of therapy?

Most metastatic epidural tumors arise in a vertebral body and invade the anterior epidural space. Therefore, it is logical to decompress the spine anteriorly and not by traditional laminectomy. Surgical decompression is indicated if relapse occurs after radiotherapy and further radiation cannot be administered, if there is neurological deterioration during radiotherapy, and when histological diagnosis of the primary tumor is lacking. This pilot study consists of eleven consecutive anterior decompressions of the spine performed in nine patients. In seven instances other treatment modalities had been exhausted, and in four patients a tissue diagnosis was lacking. Before operation eight of the patients were nonambulatory, four of them paraplegic. Following decompression all but one patient became ambulatory. At operation the main bulk of the compressing tumor was found anterior or anterolateral to the cord. Spine stabilization was done when stability was a problem. Wound infection in one patient was the only postoperative complication. The encouraging outcome of our management prompts us to suggest that anterior decompression of the spine should be considered more often in metastatic compression of the cord and cauda equina.

Cauda Equina↗
PubMed1982

Osteoarthritis of the hip joint and osteoporosis: a radiological study in a random population sample in Jerusalem.

The prevalence of osteoarthritis of the hip and osteoporosis of the pelvis were examined in a random population sample in Jerusalem. Of the subjects reviewed, 16.1% showed osteoporosis of the pelvis, while osteoarthritis was noted in 4.1%. In only 0.5% did osteoarthritis and osteoporosis coexist in the same individual. Osteoporosis was more prevalent in the Far East population, while osteoarthritis appeared to bear no relationship to ethnic origin. It is suggested that osteoarthritis may be associated with high levels of physical activity, a characteristic of some Eastern populations.

Age Factors↗
PubMed1981

Determination of osteoporosis in patients with fractured femoral neck using the Singh index: a Jerusalem study.

The Singh index was used to measure the degree of osteoporosis in patients with fracture of the neck of the femur and to compare its prevalence with a random population sample in Jerusalem. The frequency of osteoporosis was 22.7% among women in the fracture series as compared with 1% in the control group. These figures are much lower than those in comparable series. The Singh index was not as sensitive an indicator of spinal osteoporosis as a direct measurement of vertebral bone density and could not be correlated with the incidence of hip fractures.

Adult↗
PubMed1979

Reduction of postoperative infection rate in hip surgery: collaborative effort between orthopedic surgeons and control-of-infection team.

The success of a collaborative program between the ward staff and the control-of-infection team in reducing postoperative infection in patients undergoing hip surgery in a university hospital is described. The program was used to detect infection, to introduce control measures and to evaluate their effectiveness. The infection rate dropped from 25.7 to less than 1.0%, and this low rate was maintained over the 2 1/2 years of follow-up surveillance. The reduction in infection rate was associated with a six-day reduction (22.4%) in the duration of postoperative hospitalization.

Adult↗
PubMed1977

Osteoporosis in patients with fractured femoral neck in Jerusalem.

In an epidemiological survey on fractures of the femur in Jerusalem, the highest incidence occurred in Oriental males and the next highest in European females. In the same series of patients the frequency of senile osteoporosis was noted to be higher in the Oriental group (both male and female) as compared with that in the European group. Similarly in a randomly chosen sample of the population, osteoporosis in the Oriental sector was twice as high as in the European sector. Osteoporosis was also seen to be three to four times more common in each age group when the fracture series was compared with the randomly chosen sample. No evidence of osteomalacia was noted in these patients.

Activities of Daily Living↗