Impedance of a goat eye lens

Cyclins are essential proteins in cell cycle control, and their deranged expression has been reported to be associated with malignant transformation. Involvement of cyclins in the development of endometrioid carcinomas of the endometrium was studied immunohistochemically using antibodies against both cyclin A and tumor suppressor gene product p53, and their expression was compared with that of Ki-67 antigen. Sixty-two cases of endometrial endometrioid carcinoma and 20 cases of normal endometrium (10 proliferative and 10 secretory phase) were examined. Of the 62 endometrioid carcinomas, atrophic endometrium and hyperplasia were found adjacent to the cancers in 30 and 19 cases respectively. Cyclin A was expressed in < 1% of the glandular cells of normal endometrium in the proliferative phase and in hyperplasia, but was negligible in normal secretory phase and atrophic endometrium. p53 was almost always negative in normal endometrium and hyperplasia. Of the 62 endometrioid carcinomas, 12 tumors (19.4%) overexpressed cyclin A and 21 tumors (33.8%) overexpressed p53 (positive cells > 1%). Cyclin A and p53 were more frequently expressed in poorly differentiated tumors than in well differentiated tumors (cyclin A, p = 0.002; p53, p = 0.016). In addition, cyclin A-positive cells were topographically related to those cells positive for p53 as well as Ki-67. In conclusion, the abnormal expression of cyclin A and p53 is associated with high-grade endometrial endometrioid carcinomas.     

Expression of a hypoglycosylated form of CD86 (B7-2) on human T cells with altered binding properties to CD28 and CTLA-4

CD80 (B7-1) and CD86 (B7-2) on APC provide a major costimulatory signal through interactions with CD28 on T cells. Absent from resting human T cells, CD86 is up-regulated early upon T cell activation, whereas CD80 expression appears later. Whereas T cell expression of CD80 has been implicated in costimulation, the functional significance of CD86 expression on T cells is unclear. We now demonstrate that CD86 expressed on human CD4+ T cell clones does not provide a costimulatory signal for other CD4+ T cell clones. Binding studies using CD28-Ig and CTLA-4-Ig fusion proteins demonstrate that CD86 expressed on T cells has significantly reduced binding affinity for CTLA-4 and no detectable binding to CD28. Biochemical analysis demonstrates that post-translational modifications of CD86 in human T cells are different from those of CD86-transfected Chinese hamster ovary cells or EBV-transformed B cells, in that T cells express a hypoglycosylated form of CD86 on the surface membrane. Thus, our results suggest that while CD86 is expressed on a number of different cell types, its costimulatory function and affinity for its ligands may be regulated by cell type-specific post-translational modifications.     

Modified phacoemulsification in situ

We describe a phacoemulsification technique for cataracts in eyes with anticipated weak zonular apparatus. After central sculpting, a crater 90% deep is made. A horizontal fracture is created with the phaco probe and chopper. The nucleus is chopped, dividing the inferior hemisection into 2 pie-shaped pieces, which are then emulsified. Without rotating the nucleus, a groove is made at the superior hemisection and a vertical fracture created with the chopper. The bevel of the phaco probe is then turned down to emulsify each quadrant separately. This technique is especially useful in eyes with weakened zonular apparatus such as those with hypermature cataract, uveitis, long-standing glaucoma, trauma, retinitis pigmentosa, and operated retinal detachments.     

Anterior ridge preservation and augmentation using a synthetic osseous replacement graft

A 7-year retrospective study, reporting 3 cases, is presented in which particulate synthetic osseous replacement grafts were placed for ridge preservation and augmentation in the maxillary anterior region after extraction of periodontally hopeless teeth. The ability of an osseous replacement graft to prevent and correct the postextraction atrophy of the alveolar ridge, as well as its esthetic implications in fixed prosthetics, is discussed.     

Disulfide bond mapping and structural characterization of spruce budworm antifreeze protein

We have previously reported that bryostation 1 (Bryo 1) induces differentiation of chronic lymphocytic leukemia (CLL) in vitro to a hairy cell (HC) stage. This study tests the hypothesis that Bryo 1-differentiated CLL cells are more susceptible to 2-chlorodeoxyadenosine (2-CdA) than parent CLL cells. A recently established EBV-negative CLL line (WSU-CLL) from a patient resistant to chemotherapy including fludarabine was used to test this hypothesis. Both Bryo 1 (10-1000 nM) and 2-CdA (5.6-22.4 microM) exhibited a dose-dependent growth inhibitory effect on the WSU-CLL cell line. In vitro, the sequential exposure to Bryo 1 (100 nM for 72 h) followed by 2-CdA (11.2 microM) resulted in significantly higher rates of growth inhibition than either agent alone. Changes in immunophenotype, enzymes, lipids, proteins, and the DNA of WSU-CLL cells were studied before and after Bryo 1 treatment. Bryo 1 induced a positive tartrate-resistant acid phosphatase reaction and two important markers, CD11c and CD25, after 72 h of culture, confirming the differentiation of CLL to HC. The Fourier transformation infrared spectroscopic analysis showed that the amount of membrane lipids significantly increased in Bryo 1-treated cells compared to controls after 24 h, whereas the protein content, as well as the DNA content, decreased. This finding supports the change of CLL to HC. To evaluate the in vivo efficacy of Bryo 1 and 2-CdA, we used a xenograft model of CLL in WSU-CLL-bearing mice with severe combined immune deficiency. s.c. tumors were developed by injection of 10(7) WSU-CLL cells, and fragments were then transplanted into a new batch of severe combined immunodeficient mice. Bryo 1 and 2-CdA at the maximum tolerated doses (75 micrograms/kg i.p. and 30 mg/kg s.c., respectively) were administered to the mice at different combinations and schedules. The survival in days, the tumor growth inhibition ratio, the tumor growth delay, and the log10 kill of the mice treated with Bryo 1 followed by 2-CdA were significantly better than the control and other groups. We conclude that the sequential treatment with Bryo 1 followed by 2-CdA resulted in higher antitumor activity and improved animal survival.     

Salt effects on ligand-DNA binding. Minor groove binding antibiotics

Salt dependent electrostatic effects play a central role in intermolecular interactions involving nucleic acids. In this paper, the finite-difference solution to the nonlinear Poisson-Boltzmann (NLPB) equation is used to evaluate the salt dependent contribution to the electrostatic binding free energy of the minor groove binding antibiotics DAPI, Hoechst 33258 and netropsin to DNA using detailed molecular structures of the complexes. For each of these systems, a treatment based on the NLPB equation accurately describes the variation of the experimentally observed binding constant with bulk salt concentration. A solvation formalism is developed in which salt effects are described in terms of three free energy contributions: the electrostatic ion-molecule interaction free energy, delta delta G degrees im; the electrostatic ion-ion interaction free energy, delta delta G degrees ii; and the entropic ion organization free energy, delta delta G degrees org. The electrostatic terms, delta delta G degrees im and delta delta G degrees ii, have both enthalpic and entropic components, while the term delta delta G degrees org is purely a cratic entropy. Each of these terms depends significantly on salt dependent changes in the counterion and coion concentrations around the DNA. In each of the systems studied, univalent ions substantially destabilize charged ligand-DNA complexes at physiological salt concentrations. This effect involves a salt dependent redistribution of counterions near the DNA. The free energy associated with the redistribution of counterions upon binding is dominated by the unfavorable change in the electrostatic ion-molecule interactions, delta delta G degrees im, rather than the change in the cratic entropy of ion organization, delta delta G degrees org. In addition, the observed slope of the salt dependence of the free energy is determined by electrostatic ion-molecule and ion-ion interactions as well as the cratic entropy of ion release. These findings are in contrast to models in which the cratic entropy of counterion release drives binding.     

Reproducibility of the acetylene rebreathe technique for determining cardiac output

Acute and subacute extrapyramidal movement disorders are rarely reported in uremic patients. We report three such cases with basal ganglia lesions. All three had advanced renal failure with high serum creatinine levels. One of the patients had a history of ischemic heart disease and acute pulmonary edema with hypoxemia. Another patient had experienced arterial hypotension during previous hemodialysis. The third had prominent metabolic acidosis. One of the patients developed generalized dyskinesias, whereas the other two developed gait disturbances. Neuroimaging studies in all three cases showed bilateral changes in the basal ganglia. The natural history was self-limiting with gradual improvement. Diminution of the basal ganglia lesions was demonstrated on follow-up imaging in two of the three cases. We conclude that acute or subacute movement disorders with bilateral basal ganglia lesions may occur in uremia. Hypoperfusion with global brain ischemia and selective vulnerability of the basal ganglia to uremic toxins may account for these lesions.     

Decreased amniotic fluid volume at < 32 weeks of gestation is associated with decreased fetal movements

The objective of this study was to assess the relationship between amniotic fluid volume (AFV) and fetal movements at < 32 weeks gestation as assessed by routine biophysical profile (BPP). From a database of 465 consecutive nonhypertensive, nondiabetic patients delivering at < 32 weeks gestation, patients with singleton, nonanomalous fetuses with AFV and fetal movements determined as part of a BPP assessment within 24 hours of delivery were studied. Amniotic fluid volume was scored 0 to 2, according to the following criteria: largest pocket in vertical diameter < 1 cm = 0; < 2 but > 1 cm = 1; > or = 2 cm = 2. Fetal movements (FM) were scored over 30 minutes: 0 if absent, 1 if 1 to 2 movements, 2 if > or = 3 gross (limb/trunk) movements. Variables assessed included fetal presentation, gestational age (GA), premature rupture of membranes (PROM) as a principal indication for delivery, clinical chorioamnionitis (diagnosed by previously published criteria), histologic parameters of infection (in amnion and umbilical cord assessed by a single pathologist blinded to clinical data), and neonatal outcome. Statistical analyses included contingency tables and analysis of variance with p < 0.05 considered significant. Three hundred and fifty-two patients met the inclusion criteria. One hundred and sixty-seven patients (47%) had PROM as a primary indication for delivery. Infrequently, decreased fetal well-being manifested by a BPP < 7 of 10 points was an indication for delivery despite prematurity (n = 7). Of the 352 patients, 80 (23%) had AFV = 0, 60 (17%) had AFV = 1, and 212 (60%) had AFV = 2; and 12 (3%) had FM = 0, 30 (9%) FM = 1, and 310 (88%) FM = 2. There was a significant correlation between decreased AFV and decreased fetal movements (p < 0.0001). Fetal presentation and GA were not significantly different between patients based on score of fetal movements. The incidence of clinical chorioamnionitis was significantly greater in patients with FM = 0 (p < 0.005). We conclude that decreased AFV is associated with decreased fetal movements irrespective of fetal presentation or gestational age. Neonatal outcome (umbilical vasculitis, sepsis, intraventricular hemorrhage) is affected only in unusual cases in which otherwise uncompromised (nonhypoxic, nonacidotic) fetuses have low scores on both these antepartum ultrasonographic parameters.