Traumatic flap displacement after LASIK

CASE REPORT: We present a case of traumatic displacement of corneal flap in the superior temporal quadrant 13 days after LASIK. The flap was repositioned after gentle irrigation of BSS, cleaned the interface and then drying the flap to verify its stability. In the next day the flap was adhered, clear cornea,smooth and visual acuity without correction was 1.00. DISCUSSION: We should try immediately to reposition the flap after traumatic displacement, as in this case.     

Rats recovering from unilateral barrel-cortex ischemia are capable of completing a whisker-dependent task using only their affected whiskers

Rats use their vibrissae for a variety of exploratory tasks including location of objects and discrimination of texture. This study examines recovery in vibrissal function following a unilateral ischemic injury to the somatosensory cortex. Vibrissal function was examined in adult food-restricted rats performing on a two-texture discrimination device. Animals were trained and tested until the criteria of >80% correct choices was demonstrated on three consecutive days. Ischemic rats were constrained to use the affected whiskers by clipping the ipsilateral vibrissae. One group was tested after ischemia, a second group was trained before ischemia and then tested, and a third group was pre-trained and received whisker stimulation and tested post-ischemia. Nai;ve animals recovering from ischemia took longer to reach criteria than intact or unilateral trimmed control animals. Pre-trained animals with compression ischemia receiving whisker stimulation with sucrose water completed the task to criteria in the fewest number of trials. The results indicate that recovery of vibrissal function occurs following a unilateral ischemic injury. Histological analysis in animals without whisker stimulation indicates that the number of normal appearing cortical barrels following ischemia was inversely correlated to the number of trials needed to complete the behavioral task. This suggests that the natural recovery of the ability to discriminate textures is related to the degree of damage to the barrel cortex. The relationship between cortical barrels and behavioral recovery did not hold for the ischemic animals receiving whisker stimulation. This latter group demonstrated recovery despite marked anatomical lesions suggesting that the intervention influenced reorganization.     

The cholesterol-regulated StarD4 gene encodes a StAR-related lipid transfer protein with two closely related homologues,StarD5 and StarD6

Using cDNA microarrays, we identified StarD4 as a gene whose expression decreased more than 2-fold in the livers of mice fed a high-cholesterol diet. StarD4 expression in cultured 3T3 cells was also sterol-regulated, and known sterol regulatory element binding protein (SREBP)-target genes showed coordinate regulation. The closest homologues to StarD4 were two other StAR-related lipid transfer (START) proteins named StarD5 and StarD6. StarD4, StarD5, and StarD6 are 205- to 233-aa proteins consisting almost entirely of START domains. These three constitute a subfamily among START proteins, sharing approximately 30% amino acid identity with one another, approximately 20% identity with the cholesterol-binding START domains of StAR and MLN64, and less than 15% identity with phosphatidylcholine transfer protein (PCTP) and other START domains. StarD4 and StarD5 were expressed in most tissues, with highest levels in liver and kidney, whereas StarD6 was expressed exclusively in the testis. In contrast to StarD4, expression of StarD5 and MLN64 was not sterol-regulated. StarD4, StarD5, and StarD6 may be involved in the intracellular transport of sterols or other lipids.     

Selective disruption of protein aggregation by cyclodextrin dimers

Beta-cyclodextrin (CD) dimers (n = 11) were synthesized and tested against eight enzymes, seven of which were dimeric or tetrameric, for inhibitor activity. Initial screening showed that only L-lactate dehydrogenase and citrate synthase were inhibited but only by two specific CD dimers in which two beta-CDs were linked on the secondary face by a pyridine-2,6-dicarboxylic group. Further investigation suggested that these CD dimers inhibit the activity of L-lactate dehydrogenase and citrate synthase at least in part by disruption of protein-protein aggregation.     

Sensitivity of Escherichia coli (MutT) and human (MTH1) 8-oxo-dGTPases to in vitro inhibition by the carcinogenic metals, nickel(II), copper(II), cobalt(II) and cadmium(II)

The toxicity of Ni(II), Co(II) and Cu(II) in animals, and that of Cd(II) in cultured cells, has been associated with generation of the promutagenic lesion 8-oxo-7,8-dihydroguanine (8-oxoguanine) in DNA, among other effects. One possible source of this base may be 8-oxo-7,8- dihydro-2'-deoxyguanosine-5'-triphosphate (8-oxo-dGTP), a product of oxidative damage to the nucleotide pool, from which it is incorporated into DNA. To promote such incorporation, the metals would have to inhibit specific cellular 8-oxo-dGTPases that eliminate 8-oxo-dGTP from the nucleotide pool. The present study was designed to test such inhibition in vitro on 8-oxo-dGTPases from two different species, the human MTH1 protein and Escherichia coli MutT protein. In the presence of Mg(II), the natural activator of 8-oxo-dGTPases, all four metals were found to inhibit both enzymes. For MTH1, the IC50 values (+/- SE; n = 3-4) were 17 +/- 2 microM for Cu(II), 30 +/- 8 microM for Cd(II), 376 +/- 71 microM for Co(II) and 801 +/- 97 microM for Ni(II). For MutT, they were 60 +/- 6 microM for Cd(II), 102 +/- 8 microM for Cu(II), 1461 +/- 96 microM for Ni(II) and 8788 +/- 1003 microM for Co(II). Thus, Cu(II) and Cd(II) emerged as much stronger inhibitors than Ni(II) and Co(II), and MTH1 appeared to be generally more sensitive to metal inhibition than MutT. Interestingly, in the absence of Mg(II), the activity of the enzymes could be restored by Co(II) to 73% of that with Mg(II) alone for MutT, and 34% for MTH1, the other metals being much less or non-effective. The difference in sensitivity to metal inhibition between the two enzymes may reflect the differences in the amino acid ligands, especially the cysteine ligand, outside their evolutionarily conserved Mg(II)-binding active sites, which might indicate predominantly non-competitive or uncompetitive mechanism of the inhibition. The overall results suggest that inhibition of 8-oxo- dGTPases may be involved in the mechanisms of induction of the 8- oxoguanine lesion in DNA by the metal ions studied, especially the non- redox-active Cd(II) cation.      

Epidemiology of Wilms tumor

Wilms tumor affects approximately one child per 10,000 worldwide before the age of 15 years. Incidence rates appear to be slightly elevated for U.S. and African Blacks in comparison to Whites, but are only half as great among Asians. Several case-control studies have suggested that paternal occupational or maternal hormonal exposures during pregnancy may increase the risk of Wilms tumor, but small numbers of subjects and inconsistencies in the patterns of exposures do not permit firm conclusions to be drawn. It is unlikely that such environmental exposures play a major role in the etiology of Wilms tumor. The median age-at-onset of Wilms tumor is 38 months in the U.S. National Wilms Tumor Study series, with cases in girls occurring on average 6 months later than in boys. Patients with bilateral tumors, aniridia, cryptorchism/hypospadias, Beck-with-Wiedemann syndrome, or intralobar nephrogenic rests tend to be diagnosed much younger than average (median 17–27 months). Those with familial disease or multicentric tumors have intermediate age-at-onset distributions, while those with perilo-bar nephrogenic rests are diagnosed at older ages. The epidemiologic features suggest that somatic mosaicism, rather than a germ-line mutation, may be responsible for some of the bilateral and multicentric cases. © 1993 Wiley-Liss, Inc.     

Position paper: Imaging methods for primary renal tumors of childhood: Costs versus benefits

The patterns of disease distribution at diagnosis and during follow-up were cataloged for the primary renal tumors of childhood. These data, derived from more than 1,500 patients, were used to define the most rewarding and cost-effective imaging methods required for patient management. The basic information needed prior to surgery includes whether there is a functioning kidney on the opposite side, and whether there are lung metastases or inferior vena cava thrombi. Simple X-ray examinations and ultrasonography (US) will provide the necessary data. Postoperatively, when the histology is known, examination of the brain (MRI or CT scan) is needed for patients with the rhabdoid tumor and clear cell sarcoma of the kidney (CCSK) who are prone to develop brain lesions; and the skeletal system (bone scan, X-ray skeletal survey) for CCSK and for renal cell carcinoma patients who tend to develop bone metastases. Continuing examination of the lung (chest films) is required for all histologies except perhaps for mesoblastic nephroma, which seldom metastasizes. The opposite kidney needs follow-up (US) for 5 or more years to exclude metachronous involvement if nephrogenic rests are present in either kidney. Sophisticated imaging studies, which cost five times or more than simple X-ray examinations or US, are not warranted routinely, and should be reserved for those cases where simpler, less expensive studies do not suffice for reaching patient management decisions. © 1993 Wiley-Liss, Inc.     

Increased risk of leukaemia in patients with juvenile chronic arthritis treated with chlorambucil

Two cases of acute leukaemia have developed in a group of 77 patients treated with chlorambucil (Chl) because of severe juvenile chronic arthritis. The total follow-up from the beginning of Chl treatment in these patients was 560 years, indicating a highly increased risk of leukaemia. Despite favourable results, especially in patients with secondary amyloidosis, Chl should only be used in selected cases.