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Biomedical subjects

M Weinreb

Publications and source records attributed to M Weinreb.

At least 37 records · Page 2Linked to original sources
PubMed1996

The consistent association between Epstein-Barr virus and Hodgkin's disease in children in Kenya.

Recent studies have suggested that Epstein-Barr virus (EBV) may play a role in the etiology of Hodgkin's disease (HD). In a previous study, we used a latent membrane protein 1 (LMP1)-specific antibodies to examine archival material from 74 British children with HD and found 50% of cases to be positive. It is known that there are geographic and ethnic variations in the incidence of HD. We have investigated LMP1 status in formalin-fixed, paraffin wax-embedded lymph nodes with HD involvement from 53 children and 48 adults from Kenya using immunohistochemical staining. We also developed sensitive and specific in vitro gene amplification protocols for examining the EBV strain type in such material using several combinations of primers derived from the EBNA 2 and EBNA 3 coding regions. LMP1 positivity was present in 100% of the pediatric cases (two lymphocyte-predominant, 25 nodular sclerosis, 16 mixed cellularity, 5 lymphocyte depletion, and 5 unclassified) and in 66% of the adult cases (two of three lymphocyte-predominant, 26 of 39 nodular, sclerosis, two of two mixed cellularity, and two of four lymphocyte depletion). Tests to type the EBV strain were undertaken in 25 EBV-positive pediatric cases. A combination of type-specific polymerase chain reactions for EBNA 2 and EBNA 3C genes indicated that seven patients had type 1, eight had type 2, and 10 had dual infections with both types. Five cases with dual infections were further investigated using a sensitive in situ hybridization for the EBV-encoded, small nuclear nonpolyadenylated RNAs (EBERs). EBER transcripts were detected in Reed-Sternberg and Hodgkin cells and in occasional infiltrating lymphocytes. These observations indicate that in Kenya EBV is consistently associated with pediatric cases of HD, and that biopsies from a number of such cases appear to carry both type 1 and type 2 viral sequences.

Adolescent↗
PubMed1996

Comparison of the distribution of 3H-alendronate and 3H-etidronate in rat and mouse bones.

Alendronate and etidronate are bisphosphonates used clinically to treat diseases associated with increased bone resorption. Etidronate is less potent and was reported to cause osteomalacia. This study examines if differences in distribution of alendronate and etidronate in the skeleton can explain differences in efficacy and in effects on mineralization between the two drugs. Eight-day old rat pups were injected s.c. with 3H-alendronate or 3H-etidronate both at either 1.3 mumol/kg or at their respective pharmacological effective doses in the growing rat of 0.12 mumol/kg for alendronate and 72.8 mumol/kg for etidronate. Twelve hours after administration at 1.3 mumol/kg both drugs showed a three- to fourfold higher localization on osteoclast vs. osteoblast surface. At the pharmacologically effective doses, 3H-alendronate labeled eightfold more osteoclast surface than osteoblast surface. In contrast, 3H-etidronate labeled approximately equal fractions of osteoclast and osteoblast surface. When similar doses of 3H-etidronate and 3H-alendronate (0.24 mumol/kg 3H-etidronate vs. 0.20 mumol/kg 3H-alendronate; 1.5 mumol/kg 3H-etidronate vs. 1.2 mumol/kg 3H-alendronate; and 14.6 mumol/kg 3H-etidronate vs. 12.0 mumol/kg 3 H-alendronate) were injected intravenously into adult mice at similar specific activities, 3H-etidronate labeled 1.5-2.5 times more osteoclast surface than 3-H-alendronate, but 3 to 15 times more osteoblast surface. Consequently, the ratio between the fraction of labeled osteoclast surface and the fraction of labeled osteoblast surface ranged for 3H-alendronate from 9 to 24, whereas for 3H-etidronate the range was from 4 to 7, due to more extensive labeling of osteoblast surface by 3H-etidronate. In a third experiment, we confirmed in adult mice the previous observation made in rat pups that normal bone formation occurs over alendronate-covered bone surfaces, and found that it occurred over etidronate-covered surfaces as well. Forty nine days after s.c. administration of alendronate at 0.12 mumol/kg or etidronate at 1.3 mumol/kg or 55.3 mumol/kg into adult mice bone formed over drug label. The distance from incorporated label to bone surface for both drugs (12.7 microns for alendronate and 8.7 and 9.2 microns for etidronate) was similar to wall width (defined by cement line) in controls (10.6 microns). In conclusion, alendronate, especially at pharmacologically active doses, shows higher uptake on resorption vs. formation surfaces than etidronate. The extent of bone formation on surfaces containing alendronate or etidronate is similar and is comparable to the "wall width" in controls.

Alendronate↗
PubMed1996

The role of Epstein-Barr virus in Hodgkin's disease from different geographical areas.

Recent studies have suggested that Epstein-Barr virus (EBV) may play a role in the aetiology of Hodgkin's disease. To determine the role of EBV in childhood Hodgkin's disease in different geographical areas, immunohistochemical staining and in situ hybridisation were used to analyse latent membrane protein 1 (LMP 1) and small nuclear non-transcribed RNAs (EBER-1) respectively. Testing for EBV within the Reed-Sternberg and Hodgkin's cells was carried out in childhood Hodgkin's disease from 10 different countries. The proportion of LMP 1 positive cases varied significantly, being 50% of cases from the United Kingdom (38/75), South Africa (9/18), Egypt (7/14), and Jordan (8/16), 60% from the United Arab Emirates (6/10), 70% from Australia (11/16), 81% from Costa Rica (34/42), 88% from Iran (7/8), 90% from Greece (20/22), and 100% of the 56 cases from Kenya. A sensitive polymerase chain reaction based EBV strain typing technique was established using archival tissues. EBV strain type 1 was shown to be predominant in childhood Hodgkin's disease from the United Kingdom, South Africa, Australia, and Greece. Type 2 was predominant in Egypt. EBV strain types 1 and 2 were both detected in some cases of childhood Hodgkin's disease in the United Kingdom, Costa Rica, and Kenya. The high incidence of EBV and the presence especially in developing countries of dual infection with both strain types 1 and 2 may reflect socioeconomic conditions leading to malnutrition induced immunological impairment. The possibility of HIV infection also needs to be explored.

Adolescent↗
PubMed1994

Bone marrow from mechanically unloaded rat bones expresses reduced osteogenic capacity in vitro.

Bone formation during mechanical unloading is reduced, mainly as a result of osteoblastic hypofunction. At the same time, the total number of osteoblasts per long bone is also markedly reduced. We tested the hypothesis that the number of osteogenic precursors present in the bone marrow stroma was concomitantly diminished by using an in vitro cell culture system in which femoral adherent bone marrow cells differentiate into active osteoblasts and produce bone-like nodules. Hindlimbs of 32-day-old male rats were either immobilized (unloaded) by sciatic neurectomy (immo) or sham operated (sham) and animals were killed after 11 days. Femora were either ashed to determine bone mass or used to generate bone marrow cultures. Adherent marrow cells were cultured in the presence of ascorbic acid, beta-glycerophosphate, and dexamethasone. Bone mass was significantly reduced in unloaded femora (by 16%) and tibiae (by 18%). The number of adherent cells (determined on day 6) was reduced by 50% in the immo group. Reduced cell number did not result from slower proliferation in culture since [3H]thymidine incorporation on days 4 and 6 was similar in the two groups. The osteogenic potential in vitro of marrow from unloaded bones was diminished compared with that from loaded ones as evidenced by (1) lower alkaline phosphatase (ALP) activity per mg protein (by 25-40%, examined on days 6 and 12), and (2) reduced nodule formation (by 70%, expressed as percentage of the dish area stained with Alizarin Red S on day 21). None of these changes occurred in the contralateral limb of operated (immobilized) animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effect of loading on the migration of periodontal fibroblasts in the rat incisor.

The influence of occlusal loading on periodontal fibroblasts was investigated in hypoloaded (shortened out of occlusion), functionally loaded and hyperloaded (constant linguointrusive mechanical loads of 9.4 +/- 0.06 g) lower left rat incisors. One hour following injection of 3H-thymidine, half of the animals in each group were killed, while the remaining rats were killed 2 weeks later. The decalcified incisors were embedded in glycolmethacrylate and sectioned (2 microns) serially, perpendicularly to the long tooth axis. Labeled and unlabeled fibroblasts in the tooth-related periodontal ligament were counted in 8 x 80 microns consecutive layers. Cell density (CD) and labeling index (LI) were plotted according to their location on the apico-incisal and cementum-bone axes. Loading caused a decrease in CD and a shift of cells from the cementum towards the middle of the ligament, proportionally to load intensity and duration. The average tooth-to-bone movement of the cells was 2 microns/day in the hypoloaded and 4 microns/day in the two loaded groups. The mean daily tooth eruption rate was 975 +/- 60 microns, 499 +/- 18 microns and 103 +/- 27 microns in the hypo-, functionally- and hyperloaded teeth, respectively. The respective concomitant average daily cell migration rates in the incisal direction were 786 microns, 500 microns, and 500 microns, i.e. 80%, 100% and 485% of the tooth eruption rates. The gross disparity between cell velocity and tooth movement under conditions of restrained eruption indicates active motility of the fibroblasts, rather than their passive tooth-eruption dependent translation.

Analysis of Variance↗
PubMed1994

Histomorphometrical analysis of the effects of the bisphosphonate alendronate on bone loss caused by experimental periodontitis in monkeys.

This study tested the efficacy of alendronate, a bisphosphate, in reducing alveolar bone loss caused by experimental periodontitis in cynomolgus monkeys. Periodontitis was initiated in adult monkeys by ligating mandibular molar teeth at the cementoenamel junction (CEJ) and subsequently inoculating the ligature with Porphyromonas (Bacteroides) gingivalis. Contralateral, homologous non-ligated teeth served as controls. Animals received, intravenously, either saline (placebo) or alendronate at 0.05 or 0.25 mg/kg every 2 weeks for 16 weeks. After the animals were sacrificed, coronal sections through mandibular molars were subjected to histomorphometrical analysis. No overt side-effects were observed in any of the animals participating in this study. In placebo-treated animals, ligation and inoculation resulted in significant bone loss both at the CEJ and at the furcation. Alendronate at 0.05 mg/kg significantly reduced bone loss associated with the experimental periodontitis at both sites. In contrast, the dose of 0.25 mg/kg was ineffective in attenuating alveolar bone loss in the furcation area and only slightly effective in preventing it at the CEJ area. The results of the histomorphometric analysis correlate closely with those of the radiographic analysis of the same experiment. These data indicate that alendronate could reduce the loss of alveolar support associated with periodontitis and suggest that bisphosphonates, by virtue of their significant inhibitory action on osteoclasts, may become a treatment modality in the battle against alveolar bone destruction during periodontal disease.

Alendronate↗
PubMed1993

Expression of alpha v and beta 3 integrin subunits in rat osteoclasts in situ.

Recent findings suggest that the vitronectin receptor, a member of the integrin family, plays an important role in the attachment of osteoclasts to bone matrix. We report here the localization by in situ hybridization of the mRNA for the alpha and beta subunits of the vitronectin receptor in rat bone sections. To generate the rat-specific RNA probes used in this study, we cloned cDNA fragments of integrin chains alpha v, beta 3, and beta 5 by the polymerase chain reaction from rat cDNA. These fragments share 86-91% homology with the respective human sequences. In situ hybridization localized the alpha v and beta 3 mRNAs to regions undergoing extensive bone resorption. The histologic appearance and prestaining of bone sections for tartrate-resistant acid phosphatase (TRAP) indicated the presence of these mRNAs in osteoclasts. These observations support immunohistochemical findings that osteoclasts express high levels of the vitronectin receptor, confirm the identity of this receptor as integrin alpha v/beta 3, and suggest that osteoclasts may actively synthesize these molecules.

Amino Acid Sequence↗
PubMed1993

Dynamics of tissue changes found after mechanical loading of the rat incisor. II. A three-dimensional longitudinal study of the histopathologic aspects.

The study comprised 60 lower left rat incisors subjected to 2 weeks of loading (19.7 +/- 1.6 gm) and 5 control teeth. After the loading period, 10 rats were killed with the springs in situ, and the remainder were killed in groups of 5 at intervals of 1 through 10 weeks after the springs were removed. The teeth were cross-sectioned serially (2 microns). The distance of each section from the apex and the time of its tissue formation in relation to load removal were calculated. Bone remodeling and dental and periodontal trauma were plotted according to their location on the tooth axis and circumference. Vigorous bone remodeling continued throughout the observation period, apposition and resorption sites intermingling around the tooth. Directionality, as expressed by the resorption/apposition ratio, for the formerly tensed and stressed areas was 0.61 +/- 0.07 and 1.79 +/- 0.52, respectively. However, in some of the groups directionality was negligible or reversed. New lesions of dentin (folding and resorption) were formed for 6 weeks after loading, whereas new damage to the enamel organ and enamel matrix appeared until week 9. The integrity of the PDL deteriorated for the first 8 weeks, as evidenced by edema, cell loss, scarring, and collagen fiber disorientation. Necrosis occurred throughout the recovery period. Fiber to bone attachment was disrupted by formation of big sinusoids adjacent to the bone. The frequency of most lesions decreased toward the end of the observation period. It is suggested that tissue recovery proceeds in subsiding cycles of tissue injury/tissue repair, a process that is much more prolonged than is generally believed.

Alveolar Bone Loss↗
PubMed1993

Differential expression of insulin-like growth factor-I (IGF-I) and IGF-II messenger ribonucleic acid in growing rat bone.

Insulin-like growth factors (IGF-I and IGF-II) are among the most abundant growth factors found in bone. Although their local production has been implicated in growth and development, localization of the cells that express these proteins is not well documented. We have studied, by in situ hybridization, the temporal and spatial expression of IGF-I and IGF-II mRNA in rat long bones at different stages of postnatal bone development. In 2-day-old rats, IGF-II was highly expressed in cartilage and in the mesodermal structures that surround the bone. At later stages of bone development, the IGF-II signal decreased in intensity, but could still be detected in the growth plate of tibial bones at 3 and 5 weeks. At this stage, the IGF-II signal in the epiphyseal growth plate was unevenly distributed and was stronger in the periphery than in the center, where it was mainly concentrated in the germinal layer and in some, but not all, cartilage columns. IGF-I, on the other hand, was only faintly detected in the periosteum at the early cartilaginous stage of bone development. At later stages, IGF-I was strongly associated with regions of ossification in the trabecular bone of the metaphysis and epiphysis and along the endosteal and periosteal surfaces. Surprisingly, we did not detect at any time IGF-I mRNA in chondrocytes of the epiphyseal growth plate. These results suggest that in the rat, IGF-II plays a role in early development of bone and in the longitudinal growth of the epiphyseal plate. IGF-I is more closely associated with the osteogenic regions and does not replace the declining levels of IGF-II in the growth plate.

Aging↗
PubMed1992

Epstein-Barr virus (EBV) and Hodgkin's disease in children: incidence of EBV latent membrane protein in malignant cells.

Previous studies have detected EBV DNA by Southern blotting or in situ hybridization in biopsy material from up to 30 per cent of adult cases of Hodgkin's disease. Here we have used monoclonal antibodies specific for the EBV latent membrane protein LMP1 to examine archival material from children with Hodgkin's disease. Material from 74 cases (54 males and 20 females) was examined and 37 (30 males and 7 females) were classified as LMP1-positive in the malignant cells. LMP1 positivity was present in 4/13 (31 per cent) of lymphocyte predominant, 14/36 (39 per cent) of nodular sclerosis, 17/20 (85 per cent) of mixed cellularity, 1/2 (50 per cent) of lymphocyte depletion, and 1/3 (33 per cent) of unclassified subtypes. The positive cases by clinical stage were I 9/22 (41 per cent), II 9/20 (45 per cent), III 11/24 (46 per cent), and IV 8/8 (100 per cent). LMP1 positivity was present in 2/5 (40 per cent) children aged less than 5 years, 12/27 (44 per cent) aged 5-10 years, and 23/42 (48 per cent) aged between 10 and 15 years. The association between EBV and Hodgkin's disease in children thus appeared to be more frequent in patients with mixed cellularity and advanced disease, but examples of EBV-positive tumours were found in all histological subtypes, stages, and ages. Stepwise discriminant function analysis showed that clinical stage IV and mixed cellularity histology are independently associated with LMP1 positivity. These observations indicate that Hodgkin's disease in children is at least as strongly linked to EBV as is the disease in adults.

Adolescent↗
PubMed1992

[An ovarian tumor with structural gonadoblastoma, dysgerminoma and choriocarcinoma].

A 14 1/2-year old girl with menometrorrhagia followed by amenorrhea and abdominal pain had a pelvic resistance with limited mobility. Histology of a left ovarian tumour showed gonadoblastoma turning to dysgerminoma and associated with choriocarcinoma (M-9073/1, M-9060/3, M-90101/3). Genuine ovarian tissue was hypoplastic on both sides. In the right ovary, there were additional thecalutein cysts. The patient's karyotype was 46 XX. She has been without any relapse 2 1/2 years after chemotherapy and actinotherapy.

Adolescent↗
PubMed1991

Depression of osteoblastic activity in immobilized limbs of suckling rats.

Recently we characterized the immobilization-related osteopenia in adult rats and showed that it is caused by increased bone resorption and decreased bone formation (Weinreb et al. 1989 Bone 10:187). To assess the effect of age on disuse osteopenia, this study investigated the effects of immobilization on bone turnover in very young, suckling rats. The 15-day-old rats underwent unilateral hind limb immobilization by sciatic neurectomy; the contralateral limb was left intact and served as control. Experimental or sham-operated animals were killed after 0, 2, 4, or 12 days postsurgery. Dry, fat-free weight and ash weight were determined in both femora, and both tibiae were subjected to static and dynamic histomorphometry. Immobilization caused a progressive deficit in bone mass in the immobilized limb compared to the contralateral intact limb but did not affect femoral longitudinal growth. The total mineral content in the immobilized femora was 13.6% less than that in the intact limb by day 12. Concomitantly, tibial cancellous bone area and perimeter declined in the immobilized limb by 37.3 and 32.2%, respectively. This reduction in bone mass in the tibiae of immobilized limbs was associated with increased bone resorption, expressed as osteoclast perimeter, number of osteoclasts per mm surface, and number of osteoclasts per mm2 tissue area. Bone formation was reduced as a result of impaired osteoblast activity as evidenced by (1) decreased endocortical and trabecular mineral apposition rate; (2) reduced trabecular mineral formation rate; (3) decreased percentage of ash of the femoral dry weight; and (4) increased volume of unmineralized osteoid in the tibial metaphysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Immobilization-related bone loss in the rat is increased by calcium deficiency.

The object of this study was to investigate whether a calcium-deficient diet increases the bone loss produced by mechanical hypofunction (disuse) in the rat. Male Sprague-Dawley rats of approximately 150 g were placed on either a normal diet or a calcium-deficient diet. After 7 days, all rats underwent unilateral hind-limb immobilization by sciatic neurectomy and were sacrificed 30 hours, 72 hours, or 10 days postsurgery. Femora were ashed and the total mineral content (ash weight) was determined. Tibiae were embedded, sectioned, and stained. The metaphyseal secondary spongiosa and the diaphyseal cortical bone were subjected to histomorphometric analysis. Femoral length and serum calcium were not affected by calcium intake or immobilization. Serum parathyroid hormone levels were elevated in rats on the calcium-deficient diet compared to those on the normal diet. Calcium deficiency caused a significant reduction in femoral ash weight (20-35%), tibial cortical thickness (16-20%), and trabecular bone volume (TBV) (33-39%) at 72 hours and 10 days postsurgery. Additional loss of bone mass occurred in the immobilized limb compared to the contralateral intact limb of both dietary groups. This loss occurred earlier (30 hours postsurgery versus 72 hours) in the animals on a calcium-deficient diet and was larger compared to animals on a normal diet (10.6% versus 4.8% at 72 hours and 17.9% versus 12.45% at 10 days). The total bone loss induced by the combination of a calcium-deficient diet and immobilization in this experiment was estimated to equal 46% of femoral ash weight and 79% of tibial TBV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Aminohydroxybutane bisphosphonate inhibits bone loss due to immobilization in rats.

The purpose of this study was to document the effects of aminobutane bisphosphonate (AHBuP) on bone remodeling during immobilization in rats. Male Sprague-Dawley rats underwent unilateral sciatic neurectomy after receiving two daily subcutaneous injections of 0, 0.01, 0.10, or 1.0 mg P per kg AHBuP. Rats were sacrificed at 24 h or 10 or 20 days postimmobilization. Femora were ashed and tibiae were prepared for histomorphometric analysis. AHBuP was effective in inhibiting bone loss due to immobilization in a dose-dependent manner. The percentage loss of femoral ash weight due to immobilization decreased in a dose-dependent manner. In vehicle-treated rats, there was a significant decrease in trabecular bone volume (TBV) in the immobilized tibiae compared to the normal tibiae; in AHBuP-treated rats there was a dose-dependent increase in TBV both in the immobilized and control tibiae. The osteoid surface extent was decreased in AHBuP-treated rats in a dose-dependent manner. The mineral apposition rate was altered only in the intact leg of rats treated with 0.1 and 1.0 mg P AHBuP per kg compared to vehicle treated. Osteoclast number per mm was reduced by AHBuP treatment. In conclusion, aminohydroxybutane bisphosphonate effectively prevented the bone loss due to immobilization in this system.

Alendronate↗
PubMed1990

Different pattern of alkaline phosphatase, osteopontin, and osteocalcin expression in developing rat bone visualized by in situ hybridization.

Alkaline phosphatase (AP), osteopontin (OP), and osteocalcin (OC) are expressed during osteoblastic differentiation. However, previous studies suggested differences in the timing and possibly the site of their expression. In this study we used in situ hybridization to follow the distribution of these osteoblastic markers during bone development. Frozen sections of neonatal rat long bones and calvariae were hybridized with 35S-labeled RNA probes complementary to the AP, OP, and OC mRNAs. Controls included sections hybridized with the sense (mRNA) probes or pretreated with RNase. Positive cells were identified in all areas of bone formation of the long bones and calvariae. Based on quantitative silver grain distribution and density, high levels of OP expression were present only in osteoblasts in close proximity to bone (one to two cell layers). OC expression, apparently at lower levels than OP, was also localized to osteoblasts in contact with bone. In contrast AP, which was expressed at lower levels than OP, was present in a large number of cells, including preosteoblasts that were many layers removed from the bone-forming surface. These findings are consistent with the asynchronous expression of phenotypically related genes and suggest that AP is an earlier differentiation marker than OP and OC during the formation of endochondral and membranous bone.

Alkaline Phosphatase↗
PubMed1990

Antibody against synthetic peptide derived from Epstein-Barr virus-determined nuclear antigen 1 (EBNA-1) in child non-Hodgkin's lymphoma.

Antibody reactivity against a synthetic peptide derived from Epstein-Barr virus nuclear antigen 1 (EBNA-1) was determined in 56 cases of child non-Hodgkin's lymphoma and 31 controls. The patients were divided into subgroups based on tumour location and histology and the antibody responses in the various groups were compared. A significant increase in both IgG and IgM antipeptide titres was detected in patients with tumours localized in the abdomen. High IgG titres were also noted in Burkitt-type, lymphoblastic, and centroblastic lymphomas. On the other hand, low or nil IgG titres were found in unclassified malignant lymphomas, in four cases of centroblastic-centrocytic lymphoma and in lymphomas located in the mediastinum. Surprisingly, the occurrence of antipeptide IgM antibody was highest in those tumours, where IgG titres were low, i.e. in subjects with mediastinal tumours and in unclassified malignant lymphomas. However, with the exception of tumours localized in the abdomen and unclassified tumours, the IgM titres in positive individuals were low and comparable with titres found in a part of healthy controls.

Abdominal Neoplasms↗
PubMed1990

[Malignant lymphoma of the Burkitt type. Study of 21 cases in childhood].

From a group of 151 malignant lymphomas in childhood the authors selected 21 cases of malignant Burkitt lymphoma. The histopathological diagnosis was checked using common paraffin material, and a basic clinicopathological correlations was made. Malignant lymphoma of the Burkitt type was characterized by a diffuse type of growth with striking cellular cohesion. From the cytological aspect it was uniform with minimal differences in cell size. The presence of macrophages forming a "starry-sky" phenomenon was constant in the bioptic material. It is, however, not specific for Burkitt's lymphoma. In necroptic material macrophages were often absent and the morphology of tumour cells was altered. In the differential diagnosis it is necessary to differentiate in particular malignant lymphoblastic lymphomas and monomorphous centroblastomas. The malignant of Burkitt lymphoma type was localized in the majority of patients in the abdominal cavity, less frequently on the neck and in Waldeyer's ring. The mediastinum was not primarily affected. Five patients survive for 16-52 months after termination of oncological therapy without a relapse. Twelve patients died from generalization of the process, or from complications. Eight of those who died had a primary tumour in the abdominal cavity. The mean interval between the bioptic diagnosis and death was 3.6 months. As to the primary localization of the tumour and some other clinical and pathological data, various authors differ--these differences are discussed in relation to possible variations in the distribution of the tumour under different geographical conditions.

Burkitt Lymphoma↗