[Prevalence of hepatitis C virus infection in patients with non-Hodgkin's lymphoma]. / Prevalencia de infección por el virus de la hepatitis C en pacientes con linfomas no hodgkinianos.

BACKGROUND: To know the prevalence of HCV infection in patients diagnosed with B-NHL in our area. PATIENTS AND METHOD: A group of patients diagnosed with B-NHL between 1998-99 were carefully reviewed (serological tests, HCV RNA, laboratory studies, toxicity, response to treatment and evolution) in a transversal study. RESULTS: Overall 9/77 (11.68%) of patients tested positive for HCV. Of the 9 patients HCV(+) showed abnormal elevated trans aminases in opposition with 10.3% of patients that tested seronegative. CONCLUSION: Compared with normal individuals, we have seen a higher prevalence of HCV in our B-NHL patients. It may be possible that HCV play a role in that lymphoma's pathogenesis.

Cartilage canals in the tarsal navicular of the human foetus and infant.

We have analysed the development of the cartilage canals in the tarsal navicular in 26 human foetuses and infants, aged between 12 weeks after gestation and 10 months, using a technique of transparentation and serial histological sections of the bone. The formation of cartilage canals starts in the first 12 to 13 weeks of gestation and can be seen by transparentation at 17 weeks after gestation. They increase in number with the age of the foetus or infant and develop a branching pattern almost to the centre of the tarsal navicular. They begin and are more numerous on the dorsal surface of the cartilage structure.

Histomorphometric analysis of the epiphyseal growth plate in rats after prenatal alcohol exposure.

We studied the effect of prenatal alcohol exposure on growth in the proximal tibial growth plate in 0- and 15-day-old rats, using histomorphometric methods. Body weight and tibial length were reduced in all alcohol-exposed rats. In 15-day-old rats, these parameters were lower than in the 15-day-old controls, thus showing a persistence of the effects of ethanol. The proximal tibial growth plate showed alterations, principally in 15-day-old rats. The most notable of these was a decrease in growth plate height produced by a significant reduction in hypertrophic zone height. Likewise, there were fewer cells in this zone in alcohol-exposed rats than in controls. This work shows that prenatal ethanol exposure induces growth retardation which may be due to growth plate alterations that might reflect impaired cell function.

Why does pelvic deformity occur in experimental dislocation of the growing hip?

A three-dimensional pelvic deformity was observed when experimental dislocation of the hip was reproduced in Wistar rats using hormonal and biomechanical factors. Resection or surgical dislocation of the femoral head created its absence in the acetabular socket without pelvic deformity. Muscular contractures were observed in all animals. We conclude that progressive displacement of the femoral head could produce pelvic deformity and simultaneous alterations in the triradiate cartilage.

Pelvic deformity in experimental dislocation of the growing hip.

The hip joints of growing rats have been dislocated experimentally to determine how this affects pelvic shape and acetabular orientation. After hip dislocation the innominate bone tilts laterally in the frontal plane. It bends anteriorly in the sagittal plane and rotates contralaterally in the coronal plane. No significant acetabular anteversion develops.

Cartilage canal growth: experimental approach in the rat tibia.

This paper studies the influence of an antimitotic factor (puromycin) and a hormonal factor (thyroid hormone, TH) on canal growth. The tibiae of 15 six-day-old rats were cultured in a serum-free chemically defined medium. The cultures were carried out for as long as 6 days. Our results show: (1) canal growth is not dependent on perichondrium or chondro-epiphysis growth; (2) the canal is greater and has a complex pattern in a triiodothyronine (T3)-treated assay group; (3) round and multinucleated cells are more numerous in the T3-treated assay group than in the other groups. We hypothesize that the canal grows by a physiological phenomenon of programmed cell death and that it is stimulated by TH.

Growth of the perichondrium and the chondroepiphysis: experimental approach in the rat proximal tibial epiphysis.

In the present paper we study the participation of the perichondrium in chondroepiphysis development analyzing its in vitro growth pattern without the perichondrium. We also advance the descriptive morphological results. We have observed that the chondroepiphysis without perichondrium grew with an almost normal pattern. Most of the cells that participated in chondroepiphysis growth came from the lateral region of the growth plate.

Heterogeneity of xenografted osteosarcoma. A human sarcoma transplanted into nude mice.

Human osteoblastic osteosarcoma transplanted into nude mice developed two different subtypes of non-osteogenic sarcoma: one solid and the other cystic. This could reflect the heterogeneity of osteoblastic osteosarcoma; various tumor regions have different characteristics.

Maternal hypothyroidism and fetal chondro-osseous development in rats.

The bone development of rat fetuses from female Wistar rats thyroidectomized prior to mating was studied, between 16 and 21 days of gestation. The parameters studied in each rat fetus were fetal weight, number of fetuses per litter, radiological data and frequency of appearance of ossification centers, diaphyseal radiological length of long bones, longitudinal ratio between epiphysis and diaphysis of long bones on cleaned and stained limbs, and volumetric tibial studies on the same limbs. Our results show a delay of fetal chondro-osseous development and a delay of weight increase in fetuses from thyroidectomized rats. After onset of fetal thyroid function, the fetal development begins a catch-up growth, which is not sufficient to completely overcome development delay prior to birth.

Relationship between the cartilage canal and the perichondrium in the rat proximal tibial epiphysis.

One of the most widespread hypotheses for chondral canal morphogenesis suggests that the canal is an extension of the perichondrium. To study the possible relation between perichondrium and chondral canal morphology, the proximal epiphyses in the tibias of 42 rats were studied from birth to their 29th day. The study was divided into three periods: from birth to the 4th day before canal appearance; from the 5th day, the moment of canal appearance, until the appearance of the secondary ossification center of the epiphysis on the 9th day; the 3rd ran from this point on the 10th day until its full development. We have also divided the canal into three regions: entrance, neck and bottom. The central portion (lumen) and canal wall were analyzed in each region. Our results show the perichondrium to be a complex structure, composed of a series of cellular layers in a biphasic extracellular matrix (eosinophil and basophil). The canal walls are lined by a layer of elongated cells. In the lumen there are many different cell types: fibroblasts, histiocytes, multinuclear giant cells and multivacuolated cells. Our study of the canal, its walls and lumen show no morphological structure that is reminiscent of the perichondrium. These results suggest that the canal is not itself a continuation of the perichondrium.

Experimental trauma of the triradiate epiphysis of the acetabulum and hip dysplasia.

Experimental traumatic lesions of the iliac and pubic parts of the triradiate cartilage of the acetabulum in young Wistar rats, were created to study the effect on the development of the hip joint. Radiological, functional and morphometric results were evaluated at twelve weeks of evolution, a time when the epiphysis was mature in a control series. Interference with the pubic growth plate caused acetabular dysplasia and dislocation of the hip. Both lesions caused deformities of the acetabulum and the femoral head. It is concluded that varied traumatic lesions of the triradiate cartilage may be of prognostic significance.

Morphogenesis of cartilage canals: experimental approach in the rat tibia.

This paper studies the participation of vessels in the canal morphogenesis. The proximal chondroepiphysis of the left tibia of 44 five-day-old rats was exposed and the vessels of the intercondylar fossae, near the attachment of cruciate ligaments, were cauterized. In addition to the vascular lesion this assay induced a perichondral lesion. However, the canal appeared and joined to the secondary ossification center. 36 tibiae of 4-day-old rats were removed under sterile conditions and cultured in a serum-free chemically defined medium. The cultures were carried out for as long as 15 days. A canal lumen structure was found on the first days of culture, and grew in depth to the central region of the chondroepiphysis during the culture. The secondary ossification center was not found. The vessels and mesenchymal cells observed in the control canal were not found in the culture. We suggest that the presence of vessels, perivascular cells or perichondrium does not appear to be necessary in canal morphogenesis.

Histomorphometric differences between the lateral region and central region of the growth plate in fifteen-day-old rats.

This paper studies the central and lateral regions of the growth plate in 15-day-old rats histomorphometrically. We have established two regions within the growth plate. The central region is limited by the secondary ossification center of the epiphysis and the metaphysis, and the lateral region is placed between the perichondral ring and Hert's marginal germinative zone. This study shows that the lateral region of the growth plate in 15-day-old rats is higher and has more cells than the central region. The proliferative zone in the central region is the lowest part of the two regions. Knowledge of the quantitative differences between growth plate regions aids in the analysis of growth plate histomorphometry.

Experimental acetabular dysplasia associated with a lesion of iliopubic limb of the triradiate cartilage.

An experimental lesion was created in the iliopubic limb of the triradiate cartilage in young Wistar rats with the object of studying the role of this structure in the development of hip joint disorders. Roentgenographic, functional, morphologic, and morphometric results were evaluated during the following 12 weeks. Acetabular dysplasia, dislocation, or subluxation of the hip, deformities of the acetabulum and the femoral head, and bending and hypoplasia of the innominate bone were the most significant findings. It is concluded that a lesion of the iliopubic limb of the triradiate cartilage may be a cause of severe hip joint disorders such as acetabular dysplasia, subluxation, and dislocation.