Two novel presenilin-1 mutations (Y256S and Q222H) are associated with early-onset Alzheimer's disease

Mutations in the gene encoding presenilin 1 (PS-1) account for 50% of early-onset familial Alzheimer's disease (EOFAD) cases. In this study, we identified two missense mutations in the coding sequence of the presenilin (PS-1) gene in two EOFAD pedigrees. AD was confirmed in one pedigree by autopsy. Mutation analysis of PCR products amplified from genomic DNA templates showed two novel PS-1 mutations resulting in Gln222His and Tyr256Ser. The two novel mutations are located within predicted transmembrane domains five (TM-5) and six (TM-6), respectively, and are associated with very early ages of onset. The Tyr256Ser is associated with one of the youngest age of AD onset, 25 years, which is consistent with a drastic change in function of the altered PS-1 protein. A morphometric analysis of the cortical degenerative changes of the Tyr256Ser case, showed severe involvement of the primary motor cortex, which correlated well with the pyramidal changes, including tetraspasticity. Immunoblot analysis showed the Tyr256Ser case had the greatest expression of Abeta(1-40) and Abeta(1-42), which was confirmed by ELISA, compared to other PS-1 mutant FAD cases and age-matched controls and, thus, contributes to the severity of the disease pathology.     

Interstitial Capillary in Normal and in Transplanted Kidneys: An Ultrastructural Study

Knowledge about the normal structure and pathology of interstitial capillary is limited. Splitting and multilayering of the basal membrane (BM), as a marker of chronic rejection, has been published in association with transplant glomerulopathy. The authors investigated the ultrastructural features of the interstitial capillary basal membrane in normal (15 biopsies) and in transplanted kidneys (27 biopsies from 21 patients), expressing transplant glomerulopathy (8 biopsies from 6 patients), acute tubulo-interstitial rejection (9 biopsies from 6 patients), and recurrent or de novo glomerulonephritis (10 biopsies from 8 patients). All biopsies were fixed in 1%OsO 4, embedded in Epon, and examined by electron microscope. Measurements of the interstitial capillary BM were made. The BM of interstitial capillary of intact kidney was a homogenous continuous structure, 88 nm in width on average. Thickening with diffuse multilayering of BM was most intensive in patients with transplant glomerulopathy, and much less intensive in patients with acute tubulointerstitial rejection and in patients with recurrent or de novo glomerulonephritis. These findings may provide the first information about the morphology of the normal basal lamina of interstitial capillary and support the diagnostic value of interstitial capillary changes in chronic rejection.     

Fibrillary noncongophilic renal and extrarenal deposits: a report on 10 cases

Cases in which glomerular deposits of Congo red negative amyloid-like fibrils were demonstrated by electron microscopic identification are included in this study. In the 1,266 kidney biopsies studied, there were 9 biopsies from 8 patients with fibrillary glomerulonephritis and 2 biopsies from 2 patients with systemic lupus. In 1 case of fibrillary glomerulonephritis (FGN), autopsy was performed. Electron microscopic examination showed glomerular (100%) and extraglomerular (60%) fibrillary deposits in the biopsy samples of patients with FGN and also in patients with systemic lupus. In the autopsy case, similar fibrillary deposits were demonstrated in the kidney, pancreas, spleen, lungs, and liver. The diameter of the fibrils, which were arranged similarly in all cases, varied from 8 to 27 nm individually, the length being about 1.5 μm. The authors speculate that extraglomerular kidney fibrillary deposits concurrent with the same type of deposits in other organs suggests systemic manifestation of FGN.     

De novo diabetic nephropathy on renal allografts

BACKGROUND: Posttransplant diabetes mellitus (PTDM) is a well-recognized clinical problem following renal transplantation. Long-term risks of PTDM are similar to those of diabetes mellitus in general population. The aim of our study was to identify de novo diabetic nephropathy (DN) in our group of patients with PTDM. METHODS: Thirty-four patients with PTDM were reviewed retrospectively. Light microscopy, immunofluorescence, and electron microscopy techniques were performed in 10 of 21 patients with graft biopsy. RESULTS: Five patients (four women, one man), aged 47.4 years (range, 29 to 58), four of whom received cadaveric grafts, were found to have de novo DN. Their serum creatinine was 211.4 micromol/L (range, 140 to 294). Three patients were slightly proteinuric (0.3 to 0.5 g/L). PTDM was diagnosed 2.4 months after transplantation (range, 1 to 6). Histologic diagnosis of de novo DN was made, on average, 52.6 months after transplantation (range, 8 to 115), and 50.2 months (range, 2 to 114) after PTDM. De novo DN presented as diffuse diabetic glomerulosclerosis in four patients and nodular diabetic sclerosis in one patient, and combined with transplant glomerulopathy in all five patients. The mean graft survival time for this group of patients was equivalent with a control group. Although the difference in slopes of serum creatinine between the studied groups was clinically relevant, it was not statistically significant. CONCLUSION: In view of our findings, when histologic de novo DN was found in 5 out of 10 patients, one could conclude that de novo DN could be a frequent complication of PTDM.     

Acute ultrastructural changes of the trabecular meshwork after selective laser trabeculoplasty and low power argon laser trabeculoplasty

BACKGROUND AND OBJECTIVES: To compare the histopathological changes in the human trabecular meshwork after low power argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT) with a Q-switched, frequency-doubled, neodymium:yttrium-aluminium-garnet (Nd:YAG) laser. STUDY DESIGN/MATERIALS AND METHODS: In gonioscopically normal trabecular meshwork of three patients awaiting enucleation due to malignant melanoma of the choroid, SLT and ALT were performed 1-5 days prior to enucleation. In each eye, the lower half of trabecular meshwork received SLT, one quadrant low power (460 mW) ALT and one quadrant was left untreated. Specimens were evaluated with light and transmission electron microscopy. RESULTS: A sharp demarcation line was visible between the laser treated and untreated intact trabecular meshwork after ALT and SLT. Both lasers caused disruption of trabecular beams, but the extent of the damage was smaller after SLT. The collagen component of trabecular beams was mostly amorphous, the long-spacing collagen was scanty after ALT, but more abundant after SLT. In the intertrabecular spaces fragmented cells and tissue debris with only a few pigmented cells were observed. Some endothelial cells were desquamated, but appeared slightly better preserved after SLT than ALT. CONCLUSIONS: Our ultrastructural comparison of the morphological changes after low power ALT and SLT in patients demonstrated that both lasers caused splitting and fragmentation of the trabecular beams of the trabecular meshwork, but the extent of the damage was smaller and the preservation of long-spacing collagen better after SLT than after ALT.     

Synovial sarcoma of the soft palate in a child: a light and electron microscopic study

An extremely rare case of synovial sarcoma localized in the soft palate of a 9-year-old boy is reported, describing all details noted during light and electron microscopic observation. All features characteristic of this mesenchymal tumour were evident in the light microscopy. Electron microscopy also confirmed the diagnosis. The text includes full particulars of the therapy administered.     

Cardioprotective effects of fullerenol C(60)(Oh)(24) on a single dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm

The therapeutic utility of the anthracycline antibiotic doxorubicin is limited due to its cardiotoxicity. Our aim was to investigate the efficacy of fullerenol C(60)(OH)(24) in preventing single, high-dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm. Experiment was performed on adult female Sprague Dawley rats with chemically induced mammary carcinomas. The animals were sacrificed two days after the application of doxorubicin and/or fullerenol, and the serum activities of CK, LDH and alpha-HBDH, as well as the levels of MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS in the heart, were determined. The results obtained from the enzymatic activity in the serum show that the administration of a single dose of 8 mg/kg in all treated groups induces statistically significant damage. There are significant changes in the enzymes of LDH and CK (p < 0.05), after an i.p. administration of doxorubicin/fullerenol and fullerenol. Comparing all groups with untreated control group, point to the conclusion that in the case of a lower alpha-HBDH/LDH ratio, results in more serious the liver parenchymal damage. The results revealed that doxorubicin induced oxidative damage and that the fullerenol antioxidative influence caused significant changes in MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS level in the heart (p < 0.05). Therefore, it is suggested that fullerenol might be a potential cardioprotector in doxorubicin-treated individuals.     

Transmission electron microscopic analysis of trabecular meshwork in secondary glaucoma after intravitreal silicone oil injection

Purpose: We analyzed morphological changes in trabecular meshwork in glaucoma developing after intravitreal silicone oil injection with transmission electron microscopy (TEM). Methods: Specimens obtained from 2 patients after surgical trabeculectomy were fixed in Mc Dowell fixative in one patient and in buffered formaldehyde in the other, dehydrated and embedded in Epon. Ultrathin sections were made and stained with lead citrate and uranyl acetate for TEM. Results: In specimens mainly connective tissue sheets with disorganized and narrowed intertrabecular spaces were observed. At higher magnification the collagen sheets were composed of interstitial collagen and some of them were covered by amorphous basal membrane structures resembling material. Cellular remnants were present along the intertrabecular spaces. No other cells or clearly evident silicone oil were noted. Conclusion: Changes such as decrease in cell content, fibrosis and build-up of basement membrane-like material have been described by other authors. They are not specific and can be seen in many secondary glaucomas. No macrophages and foreign-body granulomas in response to silicone oil were present. The pathological changes in angle structures are probably caused by other mechanisms and are not induced by silicone oil itself.     

Identification of new impurities of enalapril maleate on oxidation in the presence of magnesium monoperoxyphthalate

Stress stability testing and forced degradation were used to determine the stability of enalapril maleate (EM) and to find a degradation pathway for the drug. The degradation impurities, formed under different stressed conditions, were investigated by HPLC and UPLC–MS methods. HPLC analysis showed several degradation impurities of which several were already determined, but on oxidation in the presence of magnesium monoperoxyphthalate (MMPP) several impurities of EM were observed which were not yet characterized. The HPLC methods for determination of EM were validated. The linearity of HPLC method was established in the concentration range between 0.5 and 10 μg/mL with correlation coefficient greater than 0.99. The LOD of EM was 0.2 μg/mL and LOQ was 0.5 μg/mL. The validated HPLC method was used to determine the degradation impurities in samples after stress stability testing and forced degradation of EM. In order to identify new degradation impurities of EM after forced degradation UPLC–MS/MSⁿ, Orbitrap has been used. It was found that new impurities are oxidation products: (S)-1-((S)-2-((S)-1-ethoxy-4-(o,m,p-hydroxyphenyl)-1-oxobutan-2-ylamino)propanoyl)pyrrolidine-2-carboxylic acid, (2S)-1-((2S)-2-((2S)-1-ethoxy-4-hydroxy-1-oxo-4-phenylbutan-2-ylamino)propanoyl)pyrrolidine-2-carboxylic acid. (S)-2-(3-phenylpropylamino)-1-(pyrrolidin-1-yl)propan-1-one was identified as a new degradation impurity.