Biomedical subjects
Publications and source records attributed to M Kockx.
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During a study of experimentally induced atheromatosis in hypercholesterolemic rabbits we found a heavy infiltration of the lacis cell field (G field) by lipids in the kidney. A systematic study was done in 12 rabbits receiving a dietary cholesterol supplement of 0.3% for 26 weeks and in 8 animals receiving a supplement of 2% for 8 weeks. Standard histology, immunohistochemistry for a-smooth muscle cell actin and with the macrophage specific antibody RAM 11, and transmission electron microscopy were performed. In the low cholesterol, long duration group, 90% of the G fields were involved. The lipid accumulation was mainly extracellular. The lacis cells contained moderate numbers of medium sized lipid vacuoles and showed signs of cytoplasmic damage leading to disintegration. The mesangial cells contained few dipid droplets and the matrix was normal. The arterioles were not involved. The lesion suggests an impairment of the clearance of lipids, leading to interstitial accumulation and cellular damage.
Lymphomatoid granulomatosis is a unique form of pulmonary angiitis and granulomatosis characterized histologically by a necrotizing angiocentric and angiodestructive lymphoid infiltrate, which in most cases represents a proliferation of Epstein-Barr virus infected B-cells, with a prominent T-cell reaction. The most common radiographic findings in lymphoma-toid granulomatosis are multiple rounded mass densities, often suggestive of metastatic tumour. We report a case of spontaneous pneumothorax with bronchopleural fistula in a patient suffering from lymphomatoid granulomatosis.
Developmental studies of oncogene expression and transgenic animal studies implicate c-fos and other fos and jun family members in the regulation of bone tissue formation. Therefore, to initiate experimental examination of the hypothesis that expression of fos- and jun-related genes is functionally coupled to modulation of gene expression which supports bone development, we determined levels of expression of the principle fos and jun family members during progressive differentiation of normal rat calvaria-derived osteoblasts within two contexts. First, cellular mRNA levels were quantitated under conditions where expression of serum-induced early response genes had returned to basal levels. Our findings demonstrate high levels of c-fos, c-jun, and jun B mRNA transcripts during the proliferative period of osteoblast development, while expression of fra-1 and fra-2 is enhanced during the differentiation period. jun D is constitutively expressed during the time course exhibiting only a 30% decline in levels postproliferatively, and fos B mRNA is undetectable by Northern blot analyses. Late in the developmental sequence, apoptosis is evident. At this time, fra-1 expression is completely downregulated, while c-fos, fra-2, c-jun, jun B, and jun D show a dramatic enhancement in expression. Second, we addressed differential expression of fos and jun family members in relation to serum responsiveness as a function of stages of phenotypic development. Proliferating cells exhibit a prolonged induction of fos and jun family members in response to serum. While in differentiated cells, which are refractory to growth stimulus even when exposed to fresh serum every 2 days, a spike in fos and jun expression is observed. Thus, our data demonstrate significant differences in basal and serum responsiveness of fos and jun family members over the course of osteoblast differentiation. These findings are consistent with multiple lines of evidence linking activity of these early response genes to regulation of cell growth and development of the bone tissue phenotype.
The present study was designed to evaluate the local effects of the new mitomycin C analogue KW-2149 after intravesical instillation, together with its penetration into the systemic circulation in healthy beagle dogs. Two reference dogs were treated with two instillations of mitomycin C (30 mg in 30 ml phosphate buffer). Four dogs were given two, three, four and six instillations, respectively, of KW-2149 (60 mg in 30 ml phosphate buffer). KW-2149 concentrations measured in the systemic circulation were very low and were frequently found to be below the limit of determination. The number of instillations had no influence on the KW-2149 concentrations measured in the systemic circulation. Blood analysis showed no systemic toxicity. The histopathological findings in the bladder were comparable in both groups. The number of instillations had no influence on the severity of the lesions found in the bladder wall. On the basis of its in vitro activity KW-2149 can be regarded as a promising agent for intravesical treatment of superficial bladder cancer.
We report eight cases of liver injury related to amoxycillin-clavulanate. Liver biopsy performed in seven patients revealed varying degrees of injury to interlobular bile ducts in all cases. Lesions included irregularity of the nuclei, vacuolization of the cytoplasm, lymphocytic infiltration, destruction and endothelialization of the bile duct epithelium. Ductopenia was not observed. In two patients liver injury was accompanied by prominent extrahepatic manifestations (acute interstitial nephritis in one and acute lacrimal gland inflammation and sialadenitis with prolonged xerostomia in the other). We conclude that interlobular bile-duct lesions of varying severity are a common feature in liver injury related to amoxycillin-clavulanate. Side effects of the drug include acute interstitial nephritis and sialadenitis.
This report describes a case of cholestatic jaundice caused by concretions of vegetable material obstructing the extrahepatic bile ducts. We have named this a biliary phytobezoar, by analogy with its gastric counterpart. The anomaly underlying this curiosity was a surgical cholecystogastrostomy performed 15 yr earlier.
Interrelationships between proliferation and expression of cell growth as well as bone cell-related genes were examined from two standpoints. First, the consequence of downregulating proliferation by DNA synthesis inhibition on expression of a cell cycle-regulated histone gene and genes associated with development of the bone cell phenotype (type I collagen, alkaline phosphatase, osteopontin, and osteocalcin) was investigated. Second, the requirement for stringent growth control to support functional relationships between expression of proliferation and differentiation-related genes was explored. Parameters of cell growth and osteoblast-related gene expression in primary cultures of normal diploid osteoblasts, that initially express proliferation-dependent genes and subsequently postproliferative genes associated with mature bone cell phenotypic properties, were compared to those operative in ROS 17/2.8 osteosarcoma cells that concomitantly express cell growth and mature osteoblast phenotypic genes. Our findings indicate that in both normal diploid osteoblasts and osteosarcoma cells, expression of the cell cycle regulated histone genes is tightly coupled with DNA synthesis and controlled predominantly at a posttranscriptional level. Inhibition of proliferation by blocking DNA synthesis with hydroxyurea upregulates a subset of developmentally expressed genes that postproliferatively support progressive establishment of mature osteoblast phenotypic properties (e.g., alkaline phosphatase, type 1 collagen, and osteopontin). However, the osteocalcin gene, which is expressed during the final stage of osteoblast differentiation when extracellular matrix mineralization occurs, is not upregulated. Variations in the extent to which inhibition of proliferation in normal diploid osteoblasts and in ROS 17/2.8 osteosarcoma cells selectively affects transcription and cellular levels of mRNA transcripts from bone cell-related genes (e.g., osteocalcin) may reflect modifications in proliferation/differentiation interrelationships when stringent growth control is abrogated.
The MRI features of a hibernoma have been described, as no previous report of MRI findings was found in the literature. The hibernoma presents as a well-delineated soft tissue mass with tissue attenuation intermediate between that of skeletal muscle and subcutaneous fat. Marked contrast enhancement is noted.
1. The present study examined the responses of the rabbit carotid artery to five vasoconstrictors after neo-intima formation induced by perivascular collar treatment and evaluated the role of constitutive and inducible nitric oxide (NO) synthase and endothelial cells (ECs). 2. Ring segments of the rabbit carotid artery were mounted in organ chambers for isometric tension recording. Neo-intima-bearing vessels developed less force (Emax) in response to KCl, the thromboxane-mimetic U-46619 and 5-hydroxytryptamine (5-HT), but not to angiotensin I and II. 3. The collar-treatment increased the sensitivity to 5-HT, and decreased the sensitivity to angiotensin II. The sensitivity to U-46619 and angiotensin I remained unchanged. 4. Mechanical removal of ECs and inhibition of NO biosynthesis by NG-monomethyl-L-arginine (L-NMMA) and NG-nitro-L-arginine (L-NOARG) increased the sensitivity to 5-HT in sham and collar-treated segments to the same extent. The effects of collar-treatment and endothelial removal or treatment with inhibitors of NO biosynthesis were additive. Inhibition of NO biosynthesis failed to augment sensitivity to 5-HT after endothelial denudation. L-NOARG increased the force development to KCl in sham and collar-treated segments to the same extent. However, L-NMMA and L-NOARG failed to augment the contractile responses of neo-intima-bearing vessels to 5-HT and KCl after endothelial removal. 5. The responses to angiotensin I were not altered, either by the neo-intima or by endothelial removal. In arteries with a neo-intima the sensitivity to angiotensin II was decreased. Removal of the endothelium or incubation with L-NOARG counteracted this rightward shift and increased Emax.6. Our results demonstrate that contractions to 5-HT, angiotensin II and KCl are modulated by NO in both sham and neo-intima-bearing vessels. Inhibition of NO biosynthesis and collar treatment resulted in additive effects on the EC50 values, suggesting that the 5-HT and angiotension (AT) receptors on the smooth muscle cells are also modified by the formation of a neo-intima. Furthermore, the reduced contractile responses of segments with a neo-intima are not due to NO formed by an inducible NO synthase in those vessels.
Atherosclerotic aneurysm of the abdominal aorta is a frequent finding in a general hospital patient population. Most complications such as rupture, thrombosis and superinfection are well known. We report on a patient with aortocaval fistulization. This rare complication was diagnosed on contrast enhanced computed tomography. Pathological correlation was obtained as attempted surgery was unsuccessful.
Eight cases of chondrosarcoma of the thoracic wall were treated during a 13-year period. The radicality of tumor resection was positively correlated with patient survival. Wide primary resection without preceding biopsy is advocated for thoracic lesions suspected from computed tomography and magnetic resonance imaging to be chondrosarcoma.
We describe a case of a 44-year-old man, presenting with progressive proptosis of the right eye. Computed Tomographic (CT)-examination showed a cystic mass in the lacrimal gland fossa of the right orbit. The lesion was removed in toto. Histological examination showed evidence of old and recent bleedings and a chronic inflammatory reaction with numerous foreign-body giant cells without epithelial lining. The diagnosis of an orbital hematic cyst was established. The pathologic and pathogenetic features of this lesion are discussed. The hematic cyst should be borne in mind as a possible cause of proptosis, due to an intraorbitally-situated mass.
Guanidino compound levels were quantitatively determined in serum, urine, liver, kidney, and brain of man and of some ureotelic animals. The guanidino compounds were separated over a cation exchange resin, using sodium citrate buffers, and detected with the fluorescence ninhydrin method. Species-specific differences in the levels of some guanidino compounds in the studied ureotelic animals are shown. alpha-Keto-delta-guanidinovaleric acid is a naturally occurring guanidino compound in ureotelic animals, and is not restricted to the pathobiochemistry of hyperargininemic patients. The fasting serum levels observed in beagles are the same as those found in hyperargininemic patients. In serum, liver, and kidney, the homoarginine, beta-guanidinopropionic acid, and gamma-guanidinobutyric acid levels are the highest in rats. The last two compounds have the highest levels of the studied guanidino compounds, with the exception of creatinine, in kidney. Specific high levels of gamma-guanidinobutyric acid and argininic acid are found in brain of rabbits.
Localized pulmonary infiltrates in leukaemic patients were until recently almost synonymous with superinfection. This case illustrates that true leukaemic pulmonary involvement should always be considered in these patients when a high peripheral blast count is present. We believe this to be the first description of cavitation in a proven leukaemic infiltrate.
We consider here the case of a young girl presenting a cystic bone mass in the left orbital roof. Although standard X-rays at first were not convincing, the findings on the CT examination and the histological aspect of the mass were typical of fibrous dysplasia. Although the exact diagnosis of fibrous dysplasia can only be made upon precise histological examination, radiological, and more specifically CT findings, may indicate this pathology.
OBJECTIVE: We studied the use of frozen section in the detection of malignancy in thyroid surgery in a large teaching hospital. MATERIALS AND METHODS: We reviewed all case notes of patients operated on for thyroid disease between January 1st 1997 and December 31st 2004. We identified 420 operations in 408 patients. Data were available for 417 operations. RESULTS: In patients with a solitary thyroid nodule, a frozen section is sometimes performed. Frozen section was done in 128 of 417 operations. The specificity for malignancy was 98.16%. The positive predictive value was 81.81% and the negative predictive value 93.85%. However the sensitivity was 56.25%. Frozen section is a time-consuming investigation. With follicular lesions it is very difficult to distinguish between benign disease and malignancy since the diagnosis of malignancy depends on capsular and/or blood vessel invasion. Also it costs about 100 Euro (approximately 125 dollars). CONCLUSION: This study confirms that adequate histopathologic diagnosis of thyroid disease is based on extensive subsampling of the specimen which is not possible during a peroperatory frozen section procedure.