Idiopathic calcinosis cutis in fingertip treated with occlusive dressing using aluminum foil: a case report.

Calcium deposition in the skin, known as calcinosis cutis, is an uncommon disorder caused by an abnormal deposit of calcium phosphate in the skin. We report a case of idiopathic calcinosis cutis in fingertip treated with surgical excision followed by the occlusive dressing using aluminum foil, and obtained significant pain relief and round-shaped fingertip which looked normal.     

The Fanconi anemia pathway is required for the DNA replication stress response and for the regulation of common fragile site stability

Fanconi anemia (FA) is a rare multi-genic, autosomal and X-linked recessive disorder characterized by hematological abnormalities, developmental defects and increased cancer susceptibility. Patient-derived FA cells display heightened sensitivity to DNA cross-linking agents such as mitomycin C (MMC). In response to DNA damaging agents, and during S-phase of the cell cycle, the FA pathway is activated via the mono-ubiquitination of FANCD2 (FANCD2-Ub), signaling its translocation to discrete nuclear foci, where it co-localizes with the central DNA repair proteins BRCA1 and RAD51. However, the exact function of activated FANCD2-Ub remains unclear. Here, we have characterized the role of the FA pathway in response to DNA replicative stress by aphidicolin (APH) and hydroxyurea (HU). The FA pathway is strongly activated in response to both agents. In addition, using patient-derived FA cell lines and siRNA targeting FANCD2, we demonstrate a functional requirement for the FA pathway in response to low doses of APH: a replicative stress treatment known to result in chromosome breakage at common fragile sites. Both the total number of chromosome gaps and breaks and breaks at the specific common fragile sites FRA3B and FRA16D were significantly elevated in the absence of an intact FA pathway. Furthermore, we demonstrate that APH activates the mono-ubiquitination of both FANCD2 and PCNA and the phosphorylation of RPA2, signaling processive DNA replication arrest. Following APH treatment, FANCD2-Ub co-localizes with PCNA (early) and RPA2 (late) in discrete nuclear foci. Our results demonstrate an integral role for the FA pathway in the DNA replication stress response.     

Induction of Thymus-Derived γδ T Cells by Escherichia coli Enterotoxin B Subunit in Peritoneal Cavities of Mice

We examined the activation of intraperitoneal T cells in BALB/c mice by the Escherichia coli enterotoxin B subunit, which induced a specific Th2 type of T-cell response to intraperitoneally coadministered bovine immunoglobulin G. The numbers of both γδ and αβ T cells increased significantly after intraperitoneal administration of the B subunit in a time-dependent manner; these numbers were not affected by the B-subunit G33D mutant, which is defective in GM₁ ganglioside-binding ability. Early after administration a small number of γδ T cells produced either interleukin-4 (IL-4) or gamma interferon, while late after administration primarily IL-10-producing γδ T cells were detected. γδ T cells induced by the B subunit did not express a characteristic V gene over the time course of the study. The induction of γδ T cells did not occur in athymic nu/nu mice but could be induced upon transplantation of fetal AKR thymus-like αβ T cells. γδ T cells in athymic nu/nu mice with a fetal thymic graft predominantly expressed the donor Thy-1.1 antigen but not the host Thy-1.2 antigen. The induction of these T cells, however, could not be restored by coadministration of the B subunit with peritoneal cells from normal mice. These results suggest that the B subunit activates intraperitoneal γδ and αβ T cells in a manner dependent upon its ability to bind to GM₁ ganglioside. γδ T cells induced by the B subunit are Th2-type cells derived from the thymus. These γδ T cells may be functionally involved in specific Th2 responses to the B subunit, which possibly acts as an adjuvant through the influence of αβ T cells.     

Lectin histochemical study on the olfactory organ of the newt,Cynops pyrrhogaster,revealed heterogeneous mucous environments in a single nasal cavity

Expression patterns of glycoconjugates were examined by lectin histochemistry in the nasal cavity of the Japanese red-bellied newt, Cynops pyrrhogaster. Its nasal cavity consisted of two components, a flattened chamber, which was the main nasal chamber (MNC), and a lateral diverticulum called the lateral nasal sinus (LNS), which communicated medially with the MNC. The MNC was lined with the olfactory epithelium (OE), while the diverticulum constituting the LNS was lined with the vomeronasal epithelium (VNE). Nasal glands were observed beneath the OE but not beneath the VNE. In addition, a secretory epithelium was revealed on the dorsal boundary between the MNC and the LNS, which we refer to as the boundary secretory epithelium (BSE) in this study. The BSE seemed to play an important role in the construction of the mucous composition of the VNE. Among 21 lectins used in this study, DBA, SBA and Jacalin showed different staining patterns between the OE and the VNE. DBA staining showed remarkable differences between the OE and the VNE; there was intense staining in the free border and the supporting cells of the VNE, whereas there was no staining or weak staining in the cells of the OE. SBA and Jacalin showed different stainings in the receptor neurons for the OE and the VNE. Furthermore, UEA-I and Con A showed different stainings for the nasal glands. UEA-I showed intense staining in the BSE and in the nasal glands located in the ventral wall of the MNC (VNG), whereas Con A showed intense staining in the BSE and in the nasal glands located in the dorsal and medial wall of the MNC (DMNG). The DMNG were observed to send their excretory ducts into the OE, whereas no excretory ducts were observed from the VNG to the OE or the VNE. These results suggested that the secretion by the supporting cells as well as the BSE and the DMNG establishes that there are heterogeneous mucous environments in the OE and the VNE, although both epithelia are situated in the same nasal cavity.     

Covalent crosslinking of myosin subfragment-1 and heavy meromyosin to actin at various molar ratios: Different correlations between ATPase activity and crosslinking extent

Summary This paper describes a systematic study of crosslinking of skeletal muscle myosin subfragment-1 (S1) and heavy meromyosin (HMM) to F-actin in the rigor state with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC). We followed the time courses of S1 or HMM head crosslinking at various actin:S1 or actin:HMM head molar ratios and the resulting superactivation of ATPase activity. The ATPase activity of the covalent complexes was measured at 0.5 M KCl, where the covalent complexes retain superactivated ATPase activity but the activity of uncrosslinked myosin heads is not activated by actin. S1 crosslinking was slowest at the actin:S1 molar ratio of 11, but faster at larger molar ratios, where more than 80% of added S1 could be crosslinked to actin. In spite of the dependence of crosslinking rate on actinS1 ratio, there were two linear correlations between ATPase activity and the extent of S1 crosslinking to actin: one for S1 crosslinked to actin at actinS1 molar ratios more than 2.71 and the other for S1 crosslinked at a molar ratio of 11. Extrapolation of the former correlation line to 100% crosslinked S1 gave an ATPase activity of 39 s^–1 for actin-S1 covalent complex at 25 °C, whereas that of the other correlation line gave 21 s^–1. The latter smaller activity suggests that the interface between actin and S1 in their rigor complexes at a molar ratio of 11 is different from that at molar ratios of more than 2.71. The acto-HMM crosslinking rate depended on the ratio of actin to HMM head, like that of S1 crosslinking to actin. The ATPase activity of crosslinked actin-HMM was, unlike that of actin-S1 covalent complexes, bell-shaped as a function of the crosslinked heads, but chymotryptic conversion of HMM to S1 in the covalent complexes made the bell-shaped characteristics disappear and increased the activity close to that of actin-Sl covalent complexes. These results indicate that some physical constraint imposed on myosin heads suppresses the actin-activated ATPase activity of HMM crosslinked to actin.     

Natural frequency/damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure

Using a digital simulation method, we analyzed the relationship between natural frequency (f _n ) and damping coefficient () of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. The pulmonary artery pressure waveform was obtained with a catheter-tip transducer and it was fed into a dynamic simulator programmed on a computer. The original waveform and the output of the simulator were compared and judged visually for the fidelity. From this analysis, the combination of f _n and was obtained and was plotted on a f _n – diagram. It showed as an area, which was convex on the left side and open on the right side. The left-convex endpoint was located at a damping coefficient of about 0.7. At a lower heart rate, this area was extended to the lower frequency side, while, at a higher heart rate, this area was limited to the higher frequency side. The f _n – diagram was also constructed theoretically by calculating the relations between natural frequencies and damping coefficients of a second order system with the amplitude and phase error tolerance set at +/–5% respectively.(Kinefuchi Y, Suzuki T, Takiguchi M, et al.: Natural frequency/Damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. J Anesth 7: 419--426, 1993)     

Myonephropathic-metabolic syndrome as a complication of cardiopulmonary bypass

We encountered eight rare cases of myonephropathic metabolic syndrome (MNMS) which developed as a complication of the femoral arterial cannulation (FAC) during cardiopulmonary bypass (CPB). Seven were boys ranging in age from 4–17 years, and all had undergone open heart surgery using CPB with a hemodilution technique. These eight corresponded to 1.9 per cent of the 420 patients treated with CPB before June, 1974. The pump priming fluid used was either Ringer’s lactate solution alone or that containing a small amount of colloidal solution. Duration of CPB ranged from 52 min to 2 hrs and 42 min, but the FAC period was more than 3 hrs in each case. Acute renal failure occurred in 3 and 2 required peritoneal dialysis. Severe respiratory insufficiency occurred in 2 and one died 3 months after the operation. The most effective means to prevent the development of MNMS seems to be the local cooling of the cannulated limb during FAC. MNMS did not occur in 444 cases of CPB with FAC after July 1974, and here local cooling was applied in all cases.     

Non-specific chemical inhibition of the Fanconi anemia pathway sensitizes cancer cells to cisplatin

ABSTRACT: BACKGROUND: Platinum compounds such as cisplatin and carboplatin are DNA crosslinking agents widely used for cancer chemotherapy. However, the effectiveness of platinum compounds is often tempered by the acquisition of cellular drug resistance. Until now, no pharmacological approach has successfully overcome cisplatin resistance in cancer treatment. Since the Fanconi anemia (FA) pathway is a DNA damage response pathway required for cellular resistance to DNA interstrand crosslinking agents, identification of small molecules that inhibit the FA pathway may reveal classes of chemicals that sensitize cancer cells to cisplatin. RESULTS: Through a cell-based screening assay of over 16,000 chemicals, we identified 26 small molecules that inhibit ionizing radiation and cisplatin-induced FANCD2 foci formation, a marker of FA pathway activity, in multiple human cell lines. Most of these small molecules also compromised ionizing radiation-induced RAD51 foci formation and homologous recombination repair, indicating that they are not selective toward the regulation of FANCD2. These compounds include known inhibitors of the proteasome, cathepsin B, lysosome, CHK1, HSP90, CDK and PKC, and several uncharacterized chemicals including a novel proteasome inhibitor (Chembridge compound 5929407). Isobologram analyses demonstrated that half of the identified molecules sensitized ovarian cancer cells to cisplatin. Among them, 9 demonstrated increased efficiency toward FA pathway-proficient, cisplatin-resistant ovarian cancer cells. Six small molecules, including bortezomib (proteasome inhibitor), CA-074-Me (cathepsin B inhibitor) and 17-AAG (HSP90 inhibitor), synergized with cisplatin specifically in FA-proficient ovarian cancer cells (2008 + FANCF), but not in FA-deficient isogenic cells (2008). In addition, geldanamycin (HSP90 inhibitor) and two CHK1 inhibitors (UCN-01 and SB218078) exhibited a significantly stronger synergism with cisplatin in FA-proficient cells when compared to FAdeficient cells, suggesting a contribution of their FA pathway inhibitory activity to cisplatin sensitization. CONCLUSION: Our findings suggest that, despite their lack of specificity, pharmaceutical inhibition of the FA pathway by bortezomib, CA-074-Me, CHK1 inhibitors or HSP90 inhibitors may be a promising strategy to sensitize cisplatin-resistant, FA pathway-proficient tumor cells to cisplatin. In addition, we identified four new small molecules which synergize with cisplatin. Further development of their analogs and evaluation of their combination with cisplatin may lead to the development of efficient cancer treatments.