EEG-study of perception of two-dimensional images of three-dimensional objects

We developed a corneal thickness mapping system with ultrasound biomicroscopy (UBM). Perpendicular section ultrasonic echo images of cornea within a radius of 2.5 mm from the center of the cornea in normal eyes were digitized and analyzed with a computer. Pachymetric maps were then represented by a color scale. Individual corneal thickness mapping will be necessary in refractive surgery and helpful in understanding pathologic states.     

Evaluation of the efficacy of thiamine and pyridoxine in the treatment of symptomatic diabetic peripheral neuropathy

Our purpose in this study was to determine the effects of cheilectomy on the mechanics of dorsiflexion of the first metatarsophalangeal (MTP) joint. Ten fresh-frozen cadaver feet were utilized, of which two demonstrated radiographic evidence of hallux rigidus. Each specimen was rigidly mounted on a custom-made slide tray that was articulated with a hinge mechanism designed to dorsiflex the first MTP joint. Range-of-motion measurements were made on the first MTP joint. Cheilectomy of 30% of the metatarsal head diameter was performed. Lateral radiographs with the beam centered on the MTP joint were taken with the joint at neutral, 20 degrees, 40 degrees, and at the limits of dorsiflexion. This process was repeated after a 50% cheilectomy was performed. The radiographs were examined for changes in joint congruence and in patterns of surface motion as the hallux moved from neutral to full dorsiflexion. Instant centers of rotation were determined by a method first described by Rouleaux. We constructed surface velocity vectors to describe patterns of motion of the first MTP joint. The mean dorsiflexion of the first MTP joint was 67.9 degrees and increased to 78.3 degrees after 30% cheilectomy. The increase in dorsiflexion was significantly greater in the two specimens with hallux rigidus (33%) than in the other specimens (12.1%). After both levels of cheilectomy, the proximal phalanx demonstrated pivoting at the resection site on the metatarsal head. This pivoting resulted in abnormal motion patterns across the MTP joint. Normal sliding motion predominated in early dorsiflexion, with compression peaking at the end stage of dorsiflexion, producing jamming of the articular surfaces. Cheilectomy significantly increased dorsiflexion of the MTP joint, but resulted in abnormal motion patterns. The increase in dorsiflexion resulted from pivoting of the proximal phalanx on the metatarsal head, resulting in anomalous velocity vectors and compression across the MTP joint.     

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Inhibition of UDP-glucuronosyltransferase by 5'-O-amino acid and oligopeptide derivatives of uridine: structure-activity relationships

The inhibitory effect of a series of 5'-O-amino acid and oligopeptide derivatives of uridine on rat liver UDP-glucuronosyltransferase (UGT) activities was investigated using two assay systems. A quantitative structure-activity relationship (QSAR) study was performed. The compounds include a lipophilic residue linked to the nucleoside by a variable spacer. Moreover, half of the derivatives have two spacers linked to the uridine moiety. Compound 1, a serine derivative of isopropylideneuridine, was found to be the most potent inhibitor of both 4-nitrophenol (4-NP) and phenolphthalein (PPh) glucuronidation, with an I50 of 0.45 mM and 0.22 mM, respectively. Kinetic studies with this substance revealed a mixed type of inhibition towards 4-NP and UDP-glucuronic acid, with apparent Ki values of 150 microM and 120 microM, respectively. The dipeptide derivatives 11-14 exhibited a low activity against 4-NP conjugation. However, a marked suppression of PPh glucuronidation was found with compounds 11 and 13. Generally, compounds with two spacers are more inhibitory against the UGT activities studied. The QSAR analysis outlined the significance of the spacers with a minimum length of 5 atoms and lipophilic residues linked to them for the inhibitory effect of the compounds. The most significant contribution to this effect is given by the six-atom spacer for both 4-NP and PPh substrates. 4-NP converting UGT isoforms seem to respond more specifically to the inhibitors: a five-atom for the first and six-atom for the second spacer enhance binding to both 4-NP and PPh conjugating isoenzymes, while a long second spacer contributes to inhibitor binding to UGT isoforms only converting PPH.     

Effects of dachengqi decoction and rhubarb on cellular electrical activities in smooth muscle of the guinea-pig taenia coli

The effects of Dachengqi decoction (DCQ) and Rhubarb (Rb) on spontaneous cellular electrical activities of guinea-pig's taenia coli has been studied by intracellular microelectrode technique. DCQ and Rb could both improve depolarization of cell membrane, speed up the burst of slow wave potential (when drug concentration was 1%, P > 0.05; 10% or 20%, P < 0.05), which was dose dependent. At the same concentration, the effects of Rb were more significant than that of DCQ. These results suggested that DCQ and Rb enhanced directly the cellular electrical excitability so as to strengthen the contraction of colon, is one of the mechanisms of these drugs in cellular level on diarrhea action. The ionic basis of the effects might be that DCQ and Rb reduced the K+conductance of cell membrane in rest state.     

Anticholinergic activity in mice and receptor-binding properties in rats of a series of synthetic tropane derivatives

AlF4- has long been known to associate with and activate the GDP-bound alpha subunits of heterotrimeric G-proteins. Recently the small guanine nucleotide binding protein Ras has also been shown to associate with AlF4- in the presence of stoichiometric amounts of its GTPase activating protein (GAP). Here we present the isolation of a stable Ras x GDP- x AlF4- x GAP ternary complex by gel filtration. In addition, we generalise the association of AlF4- with the small GTP-binding proteins by demonstrating ternary complex formation for the Cdc42, Rap and Ran proteins in the presence of their respective GAP proteins.     

Suppression of graft-versus-host disease and amplification of graft-versus-tumor effects by activated natural killer cells after allogeneic bone marrow transplantation

Bone marrow transplantation (BMT) is currently used for the treatment of a variety of neoplastic diseases. However, significant obstacles limiting the efficacy of allogeneic BMT are the occurrence of graft-versus-host disease (GvHD) and tumor relapse. Natural killer (NK) cells exert a variety of immunologic and homoeostatic functions. We examined whether adoptive transfer of activated NK cells of donor type would prevent GvHD after allogeneic BMT in mice. Lethally irradiated C57BL/6 (H-2(b)) mice, were transplanted with MHC incompatible BALB/c (H-2(d)) bone marrow cells and spleen cells and rapidly succumbed to acute GvHD. In contrast, mice that also received activated NK cells of donor type exhibited significant increases in survival. In determining the mechanism by which the NK cells prevented GvHD, mice were concurrently treated with a neutralizing antibodies to the immunosuppressive cytokine TGFbeta. Anti-TGFbeta completely abrogated the protective effects of the activated donor NK cells indicating that TGFbeta plays an important role in the prevention of GvHD by NK cells. We then examined whether activated NK cells of donor type after allogeneic BMT would induce graft-versus-tumor (GvT) effects without GvHD in mice bearing a murine colon adenocarcinoma (MCA-38). 10 d after receiving the tumor, in which the mice had demonstrable lung metastases, recipients received an allogeneic BMT with or without activated NK cells. Administration of activated NK cells resulted in significant GvT effects after allogeneic BMT as evidenced by increases in median survival and fewer lung metastasis. No evidence of GVHD was detected compared with recipients receiving spleen cells alone which also developed fewer lung metastases but in which all had succumbed to GVHD. Thus, our findings suggest that adoptive immunotherapy using activated donor NK cells combined with allogeneic BMT inhibits GvHD and promotes GvT in advanced tumor-bearing mice. These results also suggest that GvT and GvHD can be dissociable phenomena.