Immunopharmacological study of CCA (Lobenzarit disodium), an anti-arthritis agent--I. Abrogation of IL 1 secretion by LPS-stimulated human monocytes and induction of gamma-interferon production with CCA

In vitro effects of CCA, an anti-arthritis agent, were studied upon autologous mixed lymphocyte reaction (AMLR), lymphocyte mitogenesis, IL 1 and IL 2 production, immunoglobulin production and gamma-interferon (IFN) production. CCA at 50 micrograms/ml, which was not toxic to cells, blocked AMLR, IL 1 production and immunoglobulin production (IgM and IgG) significantly, while CCA at the same dose did not affect IL 2 production and lymphocyte mitogenic responses to Staphylococcus aureus Cowan I(SAC) and pokeweed mitogen(PWM). CCA at both 20 ng/ml and 20 micrograms/ml induced human gamma/IFN. Addition of IL 1 and/or IL 2 reversed inhibitory effect of CCA on AMLR. These data suggest that CCA exerts its actions by mainly affecting T cells and monocytes and can be used as an immunomodulator.     

Thin-filament-binding domains of cardiac and fast skeletal muscle troponin I isoforms as studied by epitope tagging

We examined the binding domains of cardiac and fast skeletal muscle troponin I (CTnI and FTnI, respectively) to myofibrils (MFs). Deletion mutants containing CTnI amino acid residues 1–79, 43–207 and 80–207 (CTnI-head, CTnI-tail-1 and CTnI-tail-2, respectively) and FTnI amino acid residues 1–54 and 55–182 (FTnI-head and FTnI-tail, respectively) were transiently expressed in cardiac and fast skeletal muscle cells. To monitor the intracellular localization of these exogenously introduced truncated TnIs, epitope tagging was used. CTnI-tail-1 was incorporated into cardiac MFs specifically, but CTnI-tail-2 was not assembled onto any MFs examined. This suggests that there is no potent actin filament-binding site in CTnI-tail-2. Since CTnI-tail-1 has an amino acid extension (CTnI residues 43–79) whose sequence is longer than that of CTnI-head-2; it appears that this sequence extension is important in binding to cardiac MFs. FTnI-tail, containing the inhibitory domain of actomyosin ATPase, showed intensive and specific incorporation into fast MFs. FTnI-tail was a homologous fragment of CTnI-tail-2, but the binding patterns of these two domains differed greatly from each other. It is possible that the absence of potent binding affinity of CTnI-tail-2 corresponding to the inhibitory domain of actomyosin ATPase is advantageous for continuous cardiac muscle contraction, since a potent inhibitory activity is a serious obstacle to cardiac muscle contraction. It can be assumed that distinctive binding ability of functional domains of TnI-tails reflect unique adaptations to muscles with different physiological properties.     

Encoding-related brain activity during deep processing of verbal materials: a PET study

The recent advent of neuroimaging techniques provides an opportunity to examine brain regions related to a specific memory process such as episodic memory encoding. There is, however, a possibility that areas active during an assumed episodic memory encoding task, compared with a control task, involve not only areas directly relevant to episodic memory encoding processes but also areas associated with other cognitive processes for on-line information. We used positron emission tomography (PET) to differentiate these two kinds of regions. Normal volunteers were engaged in deep (semantic) or shallow (phonological) processing of new or repeated words during PET. Results showed that deep processing, compared with shallow processing, resulted in significantly better recognition performance and that this effect was associated with activation of various brain areas. Further analyses revealed that there were regions directly relevant to episodic memory encoding in the anterior part of the parahippocampal gyrus, inferior frontal gyrus, supramarginal gyrus, anterior cingulate gyrus, and medial frontal lobe in the left hemisphere. Our results demonstrated that several regions, including the medial temporal lobe, play a role in episodic memory encoding.     

Accumulation of somatic hypermutation and antigen-driven selection in rapidly cycling surface Ig+ germinal center (GC) B cells which occupy GC at a high frequency during the primary antihapten response in mice

Well-developed germinal centers (GC) contain rapidly dividing surface immunoglobulin-negative (sIg^-) B cells (centroblasts), and most of their progeny are sIg⁺ B cells (centrocytes) in a resting state. It has been predicted that somatic hypermutation occurs in centroblasts, whereas antigen-driven selection takes place in centrocytes. The present analysis indicates that murine GC B cells bearing sIg with specificity for an immunizing antigen are in a rapidly cycling state and increase exponentially in number to occupy spleen GC at high frequency during the 1st week after primary immunization; however, the number of these cells is significantly reduced in the 2nd week of immunization. During that period, these proliferating sIg⁺ GC B cells accumulate somatic hypermutations with nucleotide exchanges indicative of affinity maturation. These sIg⁺ GC B cells co-express B7-2, ICAM-1, and LFA-1, and have potent antigen-presenting activity which results in T cell activation in vitro. These observations indicate that the sIg⁺ GC B cells accumulate somatic hypermutations and undergo antigen-driven selection through proliferation, probably upon activation by T cells. This sIg⁺ GC B cell population may represent cell cycling centrocytes; however, the possibility that these may represent centroblasts undergoing re-expression of sIg could not be excluded.     

Abnormal distribution of cathepsins in the brain of patients with Alzheimer's disease

Formalin-fixed paraffin-embedded hippocampal sections of brains with early-onset and late-onset Alzheimer's disease were studied immunohistochemically with antisera against cathepsin D and cathepsin B. In addition to the staining of neuronal perikarya, some of the senile plaques visualized by Bielshowsky silver staining and some of reactive astrocytes were positively stained with the antisera against cathepsin D and cathepsin B in brains with Alzheimer's disease. Abnormal localization of cathepsin D and cathepsin B immunoreactivity in neuronal perikarya was observed in brains with early-onset Alzheimer's disease. These findings demonstrate that the distribution of lysosomal proteases was altered in brains with Alzheimer's disease, suggesting the primary and/or secondary involvement of the lysosomal proteases in the pathological process of Alzheimer's disease.     

In vitro performance of the novel coronary sinus AutoRetroPerfusion Cannula

Myocardial salvage through coronary sinus intervention has been documented. The AutoRetroPerfusion Cannula is a novel device that is able to perfuse the coronary bed retrogradely through the coronary sinus with arterial blood generated from a peripheral artery with no need for a pump. The cannula consists of a distal end that, once secured in the coronary sinus, opens an umbrella-like membrane to create pressure in the coronary sinus, and at the same time has small channels directed backwards to the right atrium to provide pressure relief. The cannula is introduced from the axillary vein under local anesthesia and the proximal end, which consists of a graft, is anastomosed to the axillary artery to start autoperfusion once the distal end is secured in the coronary sinus and the occluding membrane is open. The AutoRetroPerfusion Cannula was tested in the in vitro mock loop under 50-120 mm Hg of proximal pressure and 50, 100, and 150 ml/min of total flow in the cannula. We were able to achieve the nominal design point of 40-80 mm Hg of distal pressure and 50-150 ml/min of distal flow by adjusting the number, diameter, and length of the small backwards channels.     

Overexpression of the Del1 gene causes dendritic branching in the mouse mesentery

In the present study, we established transgenic mice overexpressing Del1, a ligand of integrins, to examine the effect of overexpression of Del1 on vascular morphogenesis. In the wild-type mouse, mesenteric vessels are shaped like rakes consisting of a long stalk and short branches at the periphery. In contrast, those in transgenic mice showed typical dendritic architecture consisting of a few large primary branches with smaller spreading branches. The phenotype of mice overexpressing Del1 suggests the existence of a tissue-specific mechanism for branching morphogenesis in the mesentery.     

Comparison of standard and hand-assisted laparoscopic radical nephrectomy for renal cell carcinoma.

A laparoscopic radical nephrectomy (LRN) for renal cancer can be performed using two methods, hand-assisted laparoscopic surgery (HALS) and standard laparoscopic surgery (SLS). This institute initially used HALS to perform all radical nephrectomy, but gradually shifted to SLS. This study compared the two methods of radical nephrectomy: HALS vs. SLS, which were performed at a single institute. From March 1999 to November 2006, a total 129 patients with pathologically confirmed renal cell carcinoma underwent LRN, including 73 patients with the HALS and 56 patients with SLS. The median operative time was 264 minutes, and median estimated blood loss was 200 ml in the HALS group, respectively. The median operative time and median estimated blood loss in the SLS were 215 minutes and 100 ml, respectively. There was no significant difference in either the operative time or estimated blood loss between HALS and SLS. The median time to both postoperative oral intake and ambulation in the SLS were 1 day. Neither of these events after SLS was significantly shorter than that after HALS. The 4-year disease-free and overall survival rates in the HALS patients were 97.5% and 98.2%, respectively. Both the 4-year disease-free and overall survival rates in the SLS patients were 100%. Since no significant differences were observed between the two operative methods (SLS and HALS) regarding the operative data, postoperative course and oncological outcome, the surgical method for LRN can be selected according to characteristics of each surgical method.