Primary tuberculous nasal polypi—A case report

Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.     

Development of progressive glomerulosclerosis in experimental chronic serum sickness

A rat model of chronic serum sickness was used to study the pathogenesis of progressive glomerulosclerosis complicating experimental immune-complex glomerulonephritis. Chronic serum sickness was induced by immunising rats with bovine serum albumin followed by intraperitoneal administration of the antigen. Early lesions consisted of mesangial deposits of rat immunoglobulins, followed later by transient subendothelial and persistent subepithelial immune aggregates. On the basis of the peak level of proteinuria around day 80, three groups of rats were distinguished: I physiological proteinuria; II 50-500 mg/24 h; and III greater than 500 mg/24 h. The animals were killed at day 220 and the presence of mesangial proliferation, epithelial proliferation, and synechiae, as well as focal glomerulosclerosis was scored. It appeared that all and only proteinuric animals developed progressive glomerulosclerosis, although all three groups of animals passed through a phase with mesangial and subendothelial immune deposits. A strong correlation was found between the degree of proteinuria and the proportion of glomeruli affected. We conclude that the combination of mesangial and subendothelial deposits on the one hand and subepithelial deposits associated with increased protein loss on the other constitute a conditio sine qua non for the development of progressive glomerulosclerosis in this model. The use of specific antibodies to investigate the composition of the sclerotic lesions showed the presence of laminin and type IV collagen, but not of types I and III collagen in sclerotic areas of glomeruli. This indicates that the development of progressive glomerulosclerosis in this model is due to an increased production of glomerular basement membrane components by presumably solely glomerular cells after the occurrence of immunological glomerular injury.     

糖化血清蛋白测定对糖尿病监控临床意义的探讨

目的：对临床确诊糖尿病患同时测定血清葡萄糖(Glu)及糖化血清蛋白(GSP)的含量，观察二的关系，以及糖化血清蛋白水平对于评价近期(2—3周)糖尿病患血糖在体内变化的临床意义进行了观察。方法：血清葡萄糖、糖化血清蛋白测定均采用酶法测定。结果：178例糖尿病患Glu、GSP均正常3l例占17．4％；Glu、GSP均增高107例占60．1％；Glu正常、GSP增高15例占8．43％；Glu增高、GSP正常25例占14％。结论：糖化血清蛋白的含量不受即时血糖的影响，二的变化不成比例性，对评价糖尿病患2～3周病情的控制是一项灵敏可靠的指标，尤其对于住院病人的治疗与监控有一定的意义。     

Identification of non-amplifying CYP21 genes when using PCR-based diagnosis of 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH) affected pedigrees

Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.      

Chondromyxoid fibroma resembles in vitro chondrogenesis, but differs in expression of signalling molecules

Chondromyxoid fibroma is a rare benign cartilaginous bone tumour characterized by morphological features that resemble different steps of chondrogenesis in terms of both cellular morphology, ranging from spindled to rounded cells, and the extracellular matrix formed, which ranges from fibrous to cartilaginous. The presence in chondromyxoid fibroma of signalling molecules that regulate the spatial expression of proteins involved in normal cartilage proliferation and differentiation was investigated in samples from 20 patients and compared with articular chondrocytes from 11 normal donors cultivated in 3D pellet culture. Sections were stained with safranin-O and H&E, and immunohistochemistry was performed for p16, cyclin D1, FGFR3, BCL2, p21, PTHLH, PTHR1 and N-cadherin. Expression patterns were analysed using hierarchical clustering. In chondromyxoid fibroma, specific morphological features correlated with a distinct pattern of expression. Comparison with normal chondrocytes in pellet culture showed a striking morphological resemblance, but with an unmistakably different pattern of expression. N-cadherin, PTHLH, and PTHR1 were expressed to a significantly higher level (p < 0.01) in articular chondrocyte pellets but, conversely, there was significantly lower expression of cyclin D1, p16 and BCL2 (p < 0.05) in these cells. Morphological similarities reflect common steps in cartilage differentiation, albeit driven by different molecular mechanisms. The proteins we have found to be differentially expressed seem crucial for neoplastic chondrogenesis.     

The GAP-related domain of tuberin, the product of the TSC2 gene, is a target for missense mutations in tuberous sclerosis

Tuberous sclerosis is an autosomal dominant trait in which the dysregulation of cellular proliferation and differentiation results in the development of hamartomatous growths in many organs. The TSC2 gene is one of two genes determining tuberous sclerosis. Inactivating germline mutations of TSC2 in patients with tuberous sclerosis and somatic loss of heterozygosity at the TSC2 locus in the associated hamartomas indicate that TSC2 functions as a tumour suppressor gene and that loss of function is critical to expression of the tuberous sclerosis phenotype. The TSC2 product, tuberin, has a region of homology with the GTPase activating protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in vitro. Here we show that the region of homology between tuberin and human rap1GAP and the murine GAP mSpa1 is more extensive than previously reported and spans approximately 160 amino acid residues encoded within exons 34-38 of the TSC2 gene. Single strand conformation polymorphism analysis of these exons in 173 unrelated patients with tuberous sclerosis and direct sequencing of variant conformers together with study of additional family members enabled characterisation of disease associated mutations in 14 cases. Missense mutations, which occurred in exons 36, 37 and 38 were identified in eight cases, four of whom shared the same recurrent change P1675L. Each of the five different missense mutations identified was shown to occur de novo in at least one sporadic case of tuberous sclerosis. The high proportion of missense mutations detected in the region of the TSC2 gene encoding the GAP-related domain supports its key role in the regulation of cellular growth.