Hyperphosphorylation of BCL-2 family proteins underlies functional resistance to venetoclax in lymphoid malignancies

The B cell leukemia/lymphoma 2 (BCL-2) inhibitor venetoclax is effective in chronic lymphocytic leukemia (CLL); however, resistance may develop over time. Other lymphoid malignancies such as diffuse large B cell lymphoma (DLBCL) are frequently intrinsically resistant to venetoclax. Although genomic resistance mechanisms such as BCL2 mutations have been described, this probably only explains a subset of resistant cases. Using 2 complementary functional precision medicine techniques - BH3 profiling and high-throughput kinase activity mapping - we found that hyperphosphorylation of BCL-2 family proteins, including antiapoptotic myeloid leukemia 1 (MCL-1) and BCL-2 and proapoptotic BCL-2 agonist of cell death (BAD) and BCL-2 associated X, apoptosis regulator (BAX), underlies functional mechanisms of both intrinsic and acquired resistance to venetoclax in CLL and DLBCL. Additionally, we provide evidence that antiapoptotic BCL-2 family protein phosphorylation altered the apoptotic protein interactome, thereby changing the profile of functional dependence on these prosurvival proteins. Targeting BCL-2 family protein phosphorylation with phosphatase-activating drugs rewired these dependencies, thus restoring sensitivity to venetoclax in a panel of venetoclax-resistant lymphoid cell lines, a resistant mouse model, and in paired patient samples before venetoclax treatment and at the time of progression.

A reversible SRC-relayed COX2 inflammatory program drives resistance to BRAF and EGFR inhibition in BRAFV600E colorectal tumors

BRAF^V600E mutation confers a poor prognosis in metastatic colorectal cancer (CRC) despite combinatorial targeted therapies based on the latest understanding of signaling circuitry. To identify parallel resistance mechanisms induced by BRAF-MEK-EGFR co-targeting, we used a high-throughput kinase activity mapping platform. Here we show that SRC kinases are systematically activated in BRAF^V600E CRC following targeted inhibition of BRAF ± EGFR and that coordinated targeting of SRC with BRAF ± EGFR increases treatment efficacy in vitro and in vivo. SRC drives resistance to BRAF ± EGFR targeted therapy independently of ERK signaling by inducing transcriptional reprogramming through β-catenin (CTNNB1). The EGFR-independent compensatory activation of SRC kinases is mediated by an autocrine prostaglandin E₂ loop that can be blocked with cyclooxygenase-2 (COX2) inhibitors. Co-targeting of COX2 with BRAF + EGFR promotes durable suppression of tumor growth in patient-derived tumor xenograft models. COX2 inhibition represents a drug-repurposing strategy to overcome therapeutic resistance in BRAF^V600E CRC.

Oncogenic PKA signaling increases c-MYC protein expression through multiple targetable mechanisms

Genetic alterations that activate protein kinase A (PKA) are found in many tumor types. Yet, their downstream oncogenic signaling mechanisms are poorly understood. We used global phosphoproteomics and kinase activity profiling to map conserved signaling outputs driven by a range of genetic changes that activate PKA in human cancer. Two signaling networks were identified downstream of PKA: RAS/MAPK components and an Aurora Kinase A (AURKA)/glycogen synthase kinase (GSK3) sub-network with activity toward MYC oncoproteins. Findings were validated in two PKA-dependent cancer models: a novel, patient-derived fibrolamellar carcinoma (FLC) line that expresses a DNAJ-PKAc fusion and a PKA-addicted melanoma model with a mutant type I PKA regulatory subunit. We identify PKA signals that can influence both de novo translation and stability of the proto-oncogene c-MYC. However, the primary mechanism of PKA effects on MYC in our cell models was translation and could be blocked with the eIF4A inhibitor zotatifin. This compound dramatically reduced c-MYC expression and inhibited FLC cell line growth in vitro. Thus, targeting PKA effects on translation is a potential treatment strategy for FLC and other PKA-driven cancers.

Baby boy blue … and mommy too! A rare case of methaemoglobinaemia presenting simultaneously in a mother-neonate pair

Methaemoglobinaemia occurs when there is >1% methaemoglobin in erythrocytes. In an infant, they can present either congenitally or in an acquired form. We present a rare case of methaemoglobinaemia presenting simultaneously in a mother and infant pair. The mother and infant were discharged well on Day-4 post-delivery with both mother and baby recording oxygen saturation levels of 100%. On Day-7, during a routine clinic visit, they were incidentally found to be centrally cyanosed. There were no other abnormalities. On investigation, the methaemoglobin levels were elevated in the infant (23.9%) and mother (14.3%). Treatment with ascorbic acid normalised mother's methaemoglobin levels; but baby's levels remained high until the administration of oral methylene blue. Both baby and mother remained well and pink at last follow-up at 2 years 8 months of age. This case illustrates difficulties in ascertaining the cause of methaemoglobinaemia. Postdelivery, the mother-neonate pair were pink, and their haemoglobin electrophoresis were normal, hence it was unlikely to be congenital methaemoglobinaemia. The team could not identify any triggering factors for acquired methaemoglobinaemia. There was also the uncertainty of the necessity to treat the baby. This is because treatment is not without harmful effects and despite the high methaemoglobin levels, the infant was otherwise well. Only a single published paper recommended that high methaemoglobin levels must be treated, and the recommendation was not supported by evidence. Lessons learnt from our case are that neonates with methaemoglobinaemia can be safely treated with oral methylene blue, but more research is needed on the benefitrisk profile of treatment.

Irisin promotes odontogenic differentiation and angiogenic potential in human dental pulp cells

AIM

To determine whether irisin, a newly discovered myokine that links exercise-induced and metabolic homeostasis, is able to promote odontogenic differentiation and angiogenesis in human dental pulp cells (HDPCs).

METHODOLOGY

Cell viability in the presence of irisin was measured. Real-time PCR and Western blot analysis were performed to evaluate the expression levels of irisin, odontogenic and angiogenic markers. The involvement of mitogen-activated protein kinase (MAPK) and the protein kinase B (Akt) signalling pathway was evaluated by Western blot. To evaluate mineralization nodule formation, alkaline phosphatase (ALP) staining and alizarin red S staining were performed. Scratch wound assays were performed to evaluate the effects of irisin on cell migration. The data were analysed using one-way analysis of variance (anova) followed by Tukey post hoc test and Student's t-test. Statistical significance was considered at P < 0.05.

RESULTS

Irisin significantly promoted odontogenic differentiation as evidenced by formation of mineralized nodules, induction of ALP activity and upregulation of odontogenic and angiogenic markers (P < 0.05). Scratch wound assays revealed that irisin significantly increased migration of HDPCs (P < 0.05). Phosphorylation of both MAPK and Akt was increased by irisin. MAPK and Akt inhibitors inhibited mineralization, cell migration and the increased expression of odontogenic and angiogenic markers.

CONCLUSIONS

Irisin promoted odontogenic differentiation and mineralization and has the potential for angiogenesis through activation of the MAPK and Akt signalling pathways in HDPCs.

Unbiased Proteomic Profiling Uncovers a Targetable GNAS/PKA/PP2A Axis in Small Cell Lung Cancer Stem Cells

Using unbiased kinase profiling, we identified protein kinase A (PKA) as an active kinase in small cell lung cancer (SCLC). Inhibition of PKA activity genetically, or pharmacologically by activation of the PP2A phosphatase, suppresses SCLC expansion in culture and in vivo. Conversely, GNAS (G-protein α subunit), a PKA activator that is genetically activated in a small subset of human SCLC, promotes SCLC development. Phosphoproteomic analyses identified many PKA substrates and mechanisms of action. In particular, PKA activity is required for the propagation of SCLC stem cells in transplantation studies. Broad proteomic analysis of recalcitrant cancers has the potential to uncover targetable signaling networks, such as the GNAS/PKA/PP2A axis in SCLC.

Simvastatin inhibits the expression of inflammatory cytokines and cell adhesion molecules induced by LPS in human dental pulp cells

AIM

To investigate the effect of simvastatin on lipopolysaccharide (LPS)-stimulated inflammatory cytokines, cell adhesion molecules and nuclear factor-κB (NF-κB) transcription factors in human dental pulp cells (HDPCs).

METHODOLOGY

The effect of LPS and simvastatin on human dental pulp cell (HDPCs) viability was measured using a 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) assay. The expression of inflammatory cytokines and cell adhesion molecules was evaluated by reverse-transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. NF-κB transcription factors were evaluated by Western blot analysis. Statistical analysis was performed with analysis of variance (anova).

RESULTS

The viability of cells exposed to different concentrations of E. coli LPS, P. gingivalis LPS and simvastatin was not significantly different compared with that of control cells (P > 0.05). LPS significantly increased interleukin (IL)-1β (P < 0.05) and IL-6 mRNA expression (P < 0.05) and vascular cell adhesion molecule-1 (VCAM-1) (P < 0.05) and intercellular adhesion molecule-1 (ICAM-1) protein expression (P < 0.05) in HDPCs. Treatment with simvastatin significantly attenuated LPS-stimulated production of IL-1β, IL-6, VCAM-1 and ICAM-1 (P < 0.05). Treatment with simvastatin decreased LPS-induced expression of p65 and phosphorylation of IκB and also significantly decreased the phosphorylation of p65 and IκB in the cytoplasm and the level of p65 in the nucleus (P < 0.05).

CONCLUSIONS

Simvastatin has a suppressing effect on LPS-induced inflammatory cytokine, cell adhesion molecules and NF-κB transcription factors in HDPCs. Therefore, simvastatin might be a useful candidate as a pulp-capping agent in vital pulp therapy.

Behaviour of human dental pulp cells cultured in a collagen hydrogel scaffold cross-linked with cinnamaldehyde

AIM

To investigate the effects of the cross-linking agent cinnamaldehyde (CA) on differentiation of human dental pulp cells (hDPCs) cultured in a collagen hydrogel, which may be useful as a scaffold for regenerative endodontic therapy.

METHODOLOGY

The odontogenic potential of hDPCs exposed to CA was examined using alkaline phosphatase (ALP) activity, Alizarin red S staining and real-time polymerase chain reaction for odontogenic gene expression. The morphological features of hDPCs cultured in CA-treated collagen were evaluated by scanning electron microscopy. Determination of cell numbers for evaluating proliferation was assessed by optical and fluorescence microscopy. To assess the mechanical properties of collagen treated with CA, setting time, compressive strength and surface roughness were measured. Statistical analysis was performed using Student's t-test compared with control (P = 0.05).

RESULTS

CA per se did not increase ALP activity, calcium nodule formation and expression of odontogenic-related markers (P > 0.05). On the contrary, the proliferation and odontogenic differentiation of hDPCs cultured in a collagen scaffold was promoted in the presence of CA (P < 0.05). The setting time was significantly shortened, and the compressive strength and surface roughness were increased by treatment with CA (P < 0.05).

CONCLUSIONS

Cross-linking of collagen scaffolds by CA had beneficial effects with respect to attachment, proliferation and differentiation of hDPCs. Consequently, the application of cross-linking agents such as CA may represent a new strategy for dentine-pulp complex regeneration.

Transcriptional factor ATF6 is involved in odontoblastic differentiation

ATF6 is an endoplasmic reticulum (ER) membrane-bound transcription factor that regulates various cellular functions. The purpose of this study was to investigate the role of ATF6 in odontoblast differentiation. Rat tooth germs were isolated, changes in gene expression were evaluated over time, and localization of ATF6 was determined by immunohistochemistry. Human dental pulp cells (HDPCs) were cultured with 50 µg/mL ascorbic acid and 5 mmol/L β-glycerophosphate or 100 ng/mL bone morphogenetic protein 2 to induce differentiation. Translocation of ATF6 was observed by immunofluorescence and confocal microscopy. Overexpression of ATF6 was performed with an adenoviral vector. Matrix mineralization was evaluated by alizarin red staining. Immunoreactivity to anti-ATF6 was observed in the odontoblastic layer of the molar tooth germ, and expressions of ATF6, dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP1) increased gradually during tooth germ development. When HDPCs were cultured in differentiation media, ATF6, DSPP, and DMP1 expression increased with the expression of unfolded protein response (UPR) markers, BiP and CHOP. Immunofluorescence results showed that ATF6 protein moved from cytoplasm to nucleus when cells were exposed to differentiation media. Notably, overexpression of ATF6 increased DSPP and DMP1 expression, alkaline phosphatase (ALP) activity, and matrix mineralization in HDPC cultures. Inhibition of ATF6 decreased ALP activity and mineralization. These results suggest that ER membrane-bound transcriptional factor ATF6 may be involved in odontoblastic differentiation.

The Evaluation of Working Casts Prepared from Digital Impressions

Objective

The aim of this study is to evaluate the reproducibility of working casts of a digital impression system by comparing them with the original, virtual, and rapid prototyping casts.

Materials and Methods

A total of 54 cast sets in clinically stable occlusion were used. They were scanned by an iTero intraoral scanner and converted into STL format virtual casts. Rapid prototyping casts and polyurethane casts were fabricated from the iTero milling system based on the virtual casts. Several horizontal and vertical measurements were performed from the four types of casts, that is, original stone casts, virtual casts, rapid prototyping casts, and polyurethane casts of iTero. Measurement error, intraclass correlation coefficient (ICC), and differences among the casts were calculated and compared.

Results

Casts from iTero milling machines exhibited greater dimensional differences and lower ICC values than did other casts. In addition, many of the measurements of the iTero working casts showed statistically significant differences in comparison to the three other types of casts. In contrast, there were no statistically significant differences between the virtual and original casts.

Conclusion

Virtual casts made by the iTero intraoral scanner exhibited excellent reproducibility. However, the casts from the iTero milling machine showed greater dimensional differences and lower reproducibility compared to other types of casts.

SHP is involved in BMP2-induced odontoblast differentiation

Small Heterodimer Partner (SHP) interacts with diverse transcription factors such as Runx2 and regulates many cellular events including differentiation, proliferation, and energy metabolism. SHP is reported to be a positive regulator of BMP2-induced bone formation. This study aimed to clarify the role of SHP in odontoblast differentiation and matrix mineralization. Rat tooth germs were isolated, and gene expression was determined by RT-PCR and real-time PCR. Localization of SHP protein expression was identified by immunofluorescent analysis. Primary human dental pulp cells (HDPCs) were cultured with BMP2 and/or Ad-siSHP. Matrix mineralization was evaluated by Alizarin red staining. Transient transfection experiment was performed with the SHP or Dlx5 expressional plasmids and the DSPP gene. In tooth germs from post-natal days 3 to 9, BMP-2 and SHP expression increased with DSPP and DMP1 mRNA expression. In an immunostaining study, SHP was expressed in odontoblasts and surrounding osteoblasts. When HDPCs were cultured with BMP2 in mineralization-inducing medium, SHP expression also increased with an increase in DSPP expression. Down-regulation of SHP by Ad-siSHP inhibited matrix mineralization. In transient transfection experiments, overexpression of SHP was shown to enhance DSPP promoter activity through interactions between SHP and Dlx5. These results suggest that SHP may mediate BMP2 signaling to promote mineralization of the dentin matrix.

Increased apoB/A-I ratio independently associated with Type 2 diabetes mellitus: cross-sectional study in a Korean population

AIMS

The aim of this study was to investigate whether increased apolipoprotein B/apolipoprotein A-I ratio is associated with Type 2 diabetes mellitus independent of other risk factors for Type 2 diabetes.

METHODS

A total of 70,063 subjects (41,391 men and 28,672 women; mean age 41.5 years) who visited the Health Screening Center at Kangbuk Samsung Hospital for a routine medical check-up between January 2009 and December 2009 were enrolled in this study.

RESULTS

The mean apolipoprotein B/apolipoprotein A-I ratio in the study subjects was 0.66 ± 0.18. The prevalence of Type 2 diabetes increased across the apolipoprotein B/apolipoprotein A-I ratio quartiles (1.0%, 1.6%, 2.9%, and 4.8% for the 1st through 4th quartiles, respectively, P < 0.001) and homeostasis model assessment-insulin resistance (HOMA2-IR) also showed an increasing tendency by quartile (P < 0.001). The apolipoprotein B/apolipoprotein A-I ratio was correlated with age, adiposity, blood pressure, HOMA2-IR value, fasting glucose levels, and other inflammatory marker, including high-sensitivity C-reactive protein, and lipoprotein (a) levels (all P < 0.001). In a multiple logistic regression model, the highest apolipoprotein B/apolipoprotein A-I ratio quartile was associated with Type 2 diabetes, even after controlling for other risk factors for diabetes, such as age, gender, BMI, systolic blood pressure, HOMA2-IR values, high-sensitivity C-reactive protein levels, family history of diabetes, presence of metabolic syndrome, and conventional lipid parameters (odds ratio 1.31; 95% confidence interval 1.17-1.46, P < 0.001).

CONCLUSIONS

The apolipoprotein B/apolipoprotein A-I ratio was found to be associated with Type 2 diabetes independent of other risk factors for diabetes and conventional lipid parameters.

Protection of ischemic hearts by high glucose is mediated, in part, by GLUT-4

Metabolic interventions that promote glucose use during ischemia have been shown to protect ischemic myocardium and improve functional recovery on reperfusion. We evaluated whether the cardioprotection afforded by high glucose during low-flow ischemia is associated with changes in the sarcolemmal content of glucose transporters, specifically GLUT-4. Isolated rat hearts were paced at 300 beats/min and perfused under normal glucose (5 mM) or high glucose (10 mM) conditions in buffer containing 0.4 mM albumin, 0.4 mM palmitate, and 70 mU/l insulin and subjected to 50 min of low-flow ischemia and 60 min of reperfusion. To determine the importance of insulin-sensitive glucose transporters in mediating cardioprotection, a separate group of hearts were perfused in the presence of cytochalasin B (10 microM), a preferential inhibitor of insulin-sensitive glucose transporters. Ischemic contracture during low-flow ischemia and creatine kinase release on reperfusion was decreased, and the percent recovery of left ventricular function with reperfusion was enhanced in hearts perfused with high glucose (P < 0.03). Hearts perfused with high glucose exhibited increased GLUT-4 protein expression in the sarcolemmal membrane compared with control hearts under baseline conditions, and these changes were additive with low-flow ischemia. In addition, high glucose did not affect the baseline distribution of sarcolemmal GLUT-1 and blunted any changes with low-flow ischemia. These salutary effects were abolished when glucose transporters are blocked with cytochalasin B. These data demonstrate that protection of ischemic myocardium by high glucose is associated with increased sarcolemmal content of the insulin-sensitive GLUT-4 and suggest a target for the protection of jeopardized myocardium.

Clinical course of patients with IgA nephropathy between combined treatment of immunosuppressive agents and ACE inhibitor and ACE inhibitor alone

BACKGROUND

It has not been clear whether immunosuppressive therapy favorably influences renal function and proteinuria in IgA nephropathy (IgAN). Angiotensin converting enzyme inhibitor (ACEi) has an anti-proteinuric effect in IgAN. A retrospective study was done to see whether the addition of immunosuppressive therapy to ACEi produces a more excellent anti-proteinuric effect and preserves better renal function than ACEi alone.

METHODS

A total of 49 patients with proteinuria > 1.0 g/day and serum creatinine concentrations < 1.5 mg/dL were followed-up from at least 1 year to 9 years. Among them, 25 patients were treated with the combination of cyclophosphamide, prednisolone and ACEi while the other 24 were treated with ACEi alone.

RESULTS

The combination therapy or ACEi alone both reduced proteinuria with significant value (the combination group: from 5.74 +/- 5.08 to 2.29 +/- 2.77 g/day, ACEi group: from 3.85 +/- 2.54 to 1.68 +/- 1.91 g/day), while no significant differences in reduction of proteinuria were noticed between the two groups. There was no significant elevation of serum creatinine in both groups during follow-up (the combination group: from 0.91 +/- 0.20 to 1.03 +/- 0.38 mg/dL, ACEi group: from 0.93 +/- 0.27 to 0.99 +/- 0.37 mg/dL). This study showed no significant differences in the change in slope of 1/serum creatinine levels during the follow-up period between the two groups.

CONCLUSION

We conclude that immunosuppressive therapy may not be beneficial in patients with proteinuric IgAN. ACEi may be a valuable therapeutic agent avoiding serious side effects of immunosuppressive agents.

Amyloid beta -peptide-binding alcohol dehydrogenase is a component of the cellular response to nutritional stress

Amyloid beta-peptide-binding alcohol dehydrogenase (ABAD) is a member of the family of short chain dehydrogenase/reductases whose distinctive properties include the capacity to bind amyloid beta-peptide and enzymatic activity toward a broad array of substrates including n-isopropanol and beta-estradiol. In view of the wide substrate specificity of ABAD and its high activity on l-beta-hydroxyacyl-CoA derivatives, we asked whether it might also catalyze the oxidation of the ketone body d-3-hydroxybutyrate. This was indeed the case, and oxidation proceeded with K(m) of approximately 4.5 mm and V(max) of approximately 4 nmol/min/mg protein. When placed in medium with d-beta-hydroxybutyrate as the principal energy substrate, COS cells stably transfected to overexpress wild-type ABAD (COS/wtABAD) better maintained 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction, cellular energy charge, and morphologic phenotype compared with COS/vector cells. Using a severe model of metabolic perturbation, transgenic mice with targeted neuronal expression of ABAD subjected to transient middle cerebral artery occlusion showed strokes of smaller volume and lower neurologic deficit scores in parallel with increased brain ATP and decreased lactate, compared with nontransgenic controls. These data suggest that ABAD contributes to the protective response to metabolic stress, especially in the setting of ischemia.

Reduction of UV-induced cell death in the human senescent fibroblasts

We studied mechanisms by which senescent cells acquire resistance to UV-induced cellular insults. Human primary foreskin fibroblast culture was used since it undergoes cellular senescence in vitro after a limited number of passages. Senescence was induced by a brief treatment of the early passage cells with 100 microM of H2O2 for 1 h, and subsequent culture for 3 weeks. Hydrogen peroxide-treated cells showed an enhancement of senescence-associated beta-galactosidase activity. In the senescent cells, DNA fragmentation in response to UV-irradiation was found to decrease significantly compared with that in the young cells. The SAPK/JNK activation by UV irradiation was reduced in both non-treated senescent cells and the hydrogen peroxide-induced senescent cells, suggesting that a reduced DNA fragmentation by UV-irradiation in the senescent cells is closely related to the decreased SAPK/JNK activity. Since a cell cycle inhibitor, p21Waf1, has been implicated in protecting cells against apoptotic cell death, we determined p21Waf1 to assess whether its elevation has any impact on the reduction of UV-induced activation of SAPK/JNK in the senescent cells. The expression of p21Waf1 increased in both the nontreated and the hydrogen peroxide-treated senescent cells. Our study also revealed that the blockage of SAPK/JNK activation in the senescent cells was closely related to the increased level of p21Waf1. Our observation might provide clues about molecular mechanism of resistance to DNA fragmentation and the consequent cell death by UV-irradiation.

Senescence-like changes induced by hydroxyurea in human diploid fibroblasts

Hydroxyurea was found to inhibit the growth of human diploid fibroblasts, which resulted in senescence-like changes both in morphology and replicative potential similar to the replicative senescence. SA-beta-gal activity, a typical characteristic of the replicative senescence was also induced through a long-term treatment of the presenescent cells with 400-800 microgM of hydroxyurea for about 3 weeks. In addition, we determined the levels of cyclin-dependent kinase inhibitors, p21(Waf1) and p16(INK4a), and the p53 tumor suppressor in order to monitor its effect on cell cycle and stress responses. We observed a great induction of both p53 and p21(Waf1), but not of p16(INK4a) in the premature senescent cells. UV-irradiation of the premature senescent cells showed a decreased level of DNA fragmentation presumably ascribed to the reduced activation of stress-activated protein kinases. These results suggest that a chronic hydroxyurea treatment induces the cellular senescence in association with the induction of p53 and p21(Waf1).

Aging process is accompanied by increase of transglutaminase C

Crosslinking has been suggested as one of the mechanisms involved in the aging process. Among the various random or enzyme-mediated crosslinking reactions, transglutaminase (TGase)-catalyzed crosslinking activity has been proposed for its possible involvement in cell proliferation, differentiation, carcinogenesis, programmed death, and aging. Moreover, recent findings of TGase C as a putative signal transducer and cell cycle regulator has renewed interest in the study of TGase C in relation to aging phenomena. The ubiquitous presence of TGase C compared to the organ-specific localization of other types of TGases has attracted special attention as a cellular aging device. In the present investigation for in vitro studies, we have compared the pattern of TGase C in young and old human red blood cells, separated by density differentiation, and in early and late-passage or hydrogen peroxide-treated human primary fibroblasts. For in vivo study, we monitored the age-dependent changes of TGase C in the liver and brain tissues of 4, 12, 18, and 24-month-old Sprague-Dawley rats. We obtained evidence that both the activity and protein levels of TGase C were high in old RBC and late-passage or hydrogen peroxide-treated fibroblasts. Similar findings were seen in liver and brain tissue such as age-dependent increases in TGase activity and protein level in an organ-specific pattern. These data suggest that TGase C might play an active role in the cellular process with age.

Bonding strengths of porcelain repair systems with various surface treatments

STATEMENT OF PROBLEM

Metal porcelain combined surfaces are often involved in the repairing of fractured porcelain fused to metal restoration.

PURPOSE

This study investigated the effect of surface treatments on the bonding strength of porcelain fused to metal prosthesis repair.

MATERIAL AND METHODS

Specimens (8 x 4 mm) were fabricated with Biobond II casting alloy and randomly divided into three surface groups: metal, porcelain, and metal-porcelain combined surface. Biobond porcelain system and commercially available porcelain repair systems were tested. The metal surface group was further divided into two subgroups: control and sandblasting treatment (Al2O3, 50 microns, 20 seconds). In the porcelain surface group, there were three subgroups: (1) control, (2) sandblasting, and (3) 9.5% hydrofluoric acid etching for 4 minutes. The metal-porcelain surface combined group was divided into three subgroups: (1) control, (2) sandblasting, and (3) sandblasting and etching. The manufacturer's instructions for repair systems were followed for specimen preparation. Shear bond strengths of 10 specimens for each subgroup were determined with a universal testing machine after storing in distilled water at 37 degrees C for 7 days. The data were analyzed with analysis of variance and Scheffé F-test at the 95% significance level.

RESULTS

The Liner-M repair system showed significantly greater strength than the other tested systems on the metal surface with or without sandblasting treatment (p < 0.05). On the porcelain surface, the strengths of sandblasting and etching subgroups ranged from 7.2 to 16.8 MPa, and 6.8 to 16.8 MPa, respectively. There were no significant differences in bond strengths between sandblasting and combined treatment of the metal-porcelain combined surface group (p > 0.05).

CONCLUSION

The results of this study suggest that metal substrates treated with sandblasting and porcelain treated with either hydrofluoric acid or sandblasting can increase repair strength.

Treatment for dehiscence of pancreaticojejunostomy after pancreaticoduodenectomy: is resection of the residual pancreas necessary?

BACKGROUND/AIMS

Partial or total disruption of pancreaticojejunostomy (PJ) is a rare but serious complication after pancreaticoduodenectomy (PD). The recommended option of treatment is completion pancreatectomy. However, the mortality remains high as most patients were too critical to withstand the procedure.

PATIENTS AND METHODS

12 consecutive patients with dehisced PJ after PD were treated by oversewing the pancreatic stump without resection of the residual pancreas.

RESULTS

Although a high morbidity rate (75%) occurred after our management, ten patients survived reoperation, without recurrent pancreatic fistula or the need for insulin injection.

CONCLUSION

A complete pancreatectomy is not necessary for a dehisced PJ, if acute pancreatitis is not found in the residual pancreas.

Leiomyosarcoma of the gastric cardia: report of a case with unusual clinical manifestation

In an uncommon presentation of gastric leiomyosarcoma, a rare malignancy of the stomach, a patient aged 63 years was admitted due to progressive exertional dyspnea. Plain film and computed tomography of the chest showed that this patient had a mediastinal neoplasm and the pulmonary function test revealed compromised pulmonary function. Operative findings revealed that this tumor arose in the esophageal-cardiac junction with mediastinal extension; the pathology report was leiomyosarcoma. The patient recovered well and the pulmonary embarrassement was relieved in the succeeding one-year period.

Anatomy and classification of acupoints

Acupuncture points are conceived as points on the skin reflecting visceral conditions and the sites for acupuncture treatment. In the skin, acupoints tend to show higher electric conductivity and have higher concentration of neural and vascular elements as well as mast cells. Locations of some acupoints correspond to the motor points, others to the Golgi tendon organs. There is a group of midline acupoints. Most acupoints are associated with meridians and are known as meridian points. The nature of meridians is under scientific scrutiny. For identification of canine acupoints, the human meridian nomenclature was adopted.

Modulation of murine radiation-induced fibrosarcoma-1 tumor metabolism and blood flow in situ via glucose and mannitol administration monitored by 31P and 2H nuclear magnetic resonance spectroscopy

The hyperglycemia-induced in situ metabolism and blood flow changes produced in s.c. implanted murine radiation-induced fibrosarcoma-1 tumors, grown on the flanks of female C3H/HeJ mice, were examined with 31P and 2H nuclear magnetic resonance. Initial experiments verified a hyperglycemic tumor acidification similar to that reported earlier with a different substrain of mice, C3H/AnF (J.L. Evelhoch et al., Proc. Natl. Acad. Sci. USA, 81: 6496-6500, 1984). Changes in the tumor pH, phosphorus metabolites, and blood flow were then compared after administration of saline, glucose, or mannitol (a nonmetabolizable glucose analogue) using a mole-equivalent dose of the sugars (i.e., 0.8 mmol/20g mouse). Neither saline (n = 8) nor mannitol (n = 6) administration had any marked effect upon tumor pH, whereas glucose administration produced a mean maximum tumor pH reduction of 0.74 +/- 0.09 (SE; n = 9) during the 2.5 h post-glucose injection. No significant changes in high energy phosphate concentrations were observed during the same period after saline injection. After glucose injection, the [phosphocreatine] gradually decreased by 64% (P = 0.0001). After the initial 1 h post-glucose injection, the [inorganic phosphate] increased by 58% (P = 0.0001), and the [nucleoside triphosphates] decreased by 29% (P = 0.0001) during the following 1.5 h. After mannitol injection, while there was no change in [inorganic phosphate] over time (P = 0.37), the [phosphocreatine] decreased by 33% (P = 0.0001) and the [nucleoside triphosphates] decreased by 21% (P = 0.0015) within 20 min, then both the [phosphocreatine] and [nucleoside triphosphates] remained at constant levels during the following 2 h. In parallel experiments, the volumetric rate of tumor blood flow and perfusion was measured by 2H nuclear magnetic resonance monitoring of 2H2O washout kinetics (S-G. Kim and J. J. H. Ackerman, Cancer Res., 48: 3449-3453, 1988); tumor blood flow decreased by 80% (P = 0.0001, n = 11), 60% (P = 0.0031, n = 4), and 20% (P = 0.058, n = 10) at 2 h after glucose, mannitol, or saline injections, respectively. These results suggest that anaerobic glycolysis is a requirement for hyperglycemic tumor acidification. However, the decrease in tumor blood flow accompanying hyperglycemic acidification suggests that flow reduction also may be a contributing or a required cofactor for acidification via inhibition of lactic acid egress.(ABSTRACT TRUNCATED AT 400 WORDS)

[Evaluation of abdominal motor blockade using surface integrated electromyography during bupivacaine spinal anesthesia]

The study was undertaken to investigate abdominal motor blockade and compare sensory-motor differential blockade in bupivacaine spinal anesthesia by surface integrated electromyography (SIEMG). Seventeen physical status I adult male patients underwent lower limb surgery under spinal anesthesia were divided into two groups: hyperbaric bupivacaine (HB) group (n = 8) receiving 3 mL of 0.5% bupivacaine (8% glucose) and isobaric bupivacaine (IB) group (n = 9), 3 mL of 0.5% bupivacaine (glucose-free). Each patient was monitored with a blood pressure cuff, an ECG and a precordial stethoscope. Spinal anesthesia was performed at L3-4 interspace on the lateral position. Immediately following injection of bupivacaine, the patients were turned to the supine position and then simultaneous measurements of sensory blockade using pinprick, abdominal motor blockade at T6, T8, T10, T12 level using SIEMG and lower limb motor blockade using Bromage scale were made for 4 hours. Between two groups, there were no significant differences in terms of age, body weight, height as maximum level and mean times to maximum level of sensory blockade, abdominal motor blockade and lower limb motor blockade. The times of 2-segment regression of sensory blockade were 66.3 +/- 11.1 min in HB group and 115.6 +/- 31.3 min in IB group. The sensory-motor differential blockades were 4.6 +/- 0.5 segments and 4.8 +/- 2.1 segments in HB and IB groups, respectively. According to the linear regression analysis, the correlation between sensory blockade and abdominal motor blockade was better than the lower limb motor blockade and abdominal motor blockade. (Correlation coefficient (r): 0.893 vs 0.580 in HB group; 0.773 vs 0.366 in IB group).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of acupuncture on young pigs with induced enteropathogenic Escherichia coli diarrhea

Thirty-four preweaning pigs with induced enteropathogenic Escherichia coli diarrhea were treated with electroacupuncture, traditional acupuncture, or neomycin. In the group treated with electroacupuncture, points GV-1, bilateral ST-36, and Bai-hui were stimulated electrically. In the group treated with traditional acupuncture, points GV-1, bilateral ST-36, BL-20, bulb points, bilateral ear tip, and Shan-gen were used. Acupuncture points CV-12 and bilateral ST-25 also were treated with moxibustion (applying heat generated by a burning herb, Artemisia argyi). Hemoacupuncture also was applied to Shan-gen, bilateral ear tip, and bulb points. Pigs in the third group were given neomycin orally. Five pigs were inoculated with E coli, but were not treated and served as nontreated controls. At postinoculation day 5, 60% of control pigs and greater than 80% of pigs in treated groups recovered from diarrhea. However, at postinoculation day 3, recovery rates for pigs in the control and group treated with electroacupuncture were only 20 and 27.3%, respectively; whereas pigs treated with acupuncture or neomycin attained 81.8 and 71.4% of recovery rates, respectively. Seemingly, traditional acupuncture, but not electroacupuncture, was effective in controlling induced E coli diarrhea in pigs at its early stage.

Interfollicular smooth muscle in the skin of the domesticated pig (Sus scrofa)

An interfollicular smooth muscle that spans the triad of hair follicles has been identified in the skin of the domesticated pig (Sus scrofa). This muscle has been previously noted by other investigators and identified as an arrector pili muscle. However, it cannot be interpreted as such for the following reasons: 1) It lies opposite the arrector pili muscle on the follicle; 2) the orientation of its fibers is perpendicular to those of the arrector pili; 3) the two muscles are not continuous; their attachments are different; and 4) contraction of the interfollicular muscle would have little effect on erection of the hairs. Based on structural evidence, it is postulated that upon contraction the muscle draws the base of the three aligned follicles together into a triangular conformation. In so doing, it may rotate the outer two follicles of the triad. Its specific functional role is unknown.

Light microscopic morphology of low resistance skin points in the guinea pig

This study compares the light microscopic structure of low resistance skin points (LRSP) to high resistance skin points (HRSP) of the guinea pig, Previously, LRSP have been shown to coincide with acupuncture loci. Epidermal nuclei and dermal nuclei were counted at both LRSP and at control points or HRSP. In addition, hair follicles, blood vessels, and sebaceous nuclei were likewise quantitated. This data, collected in a blind manner, was then subjected to statistical analysis using a nested analysis of variance and a Student's "t" test. The former test indicated an increase in density of hair follicles at LRSP, while both demonstrated a decrease in dermal nuclei at LRSP. An interesting finding is that the epidermis at both LRSP and HRSP is indistinguishable at the light microscopic level. This was indicated by both statistical procedures. Finding of a Haarscheibe, an aggregation of Merkel cell-neurite complexes, only at HRSP tends to preclude its role as an acupuncture neurotransducer. Finally, there appeared to be no obvious qualitative differences between LRSP and HRSP observable at the light microscopic level.

A preliminary report on an attempt to modify behavior of untamed ponies by acupuncture

A preliminary study using various acupuncture techniques to modify behavior of untamed ponies was attempted. In five of the seven tested parameters, the animals's behavioral responses were unaffected by acupuncture treatments. However, substantial improvement of general behavior of the nervous ponies was observed in animals treated with jaw and scutiform points. The results are not conclusive and further testing of acupuncture as a mean of modifying animal behavior is desirable.

Experimental studies of effects of acupuncture on enterochromaffin cells: guinea pig enterochromaffin cell count after electro-acupuncture

Guinea pig acupuncture points located on the back of the animal, cranial and caudal to the last rib in the muscular groove between longissimus dorsi and iliocostalis, were treated by electro-acupuncture (EA). In the duodenum, when compared with the control, the EA-treated group showed a significant decrease of its enterochromaffin (EC) cell count. However, the sham-treated group also had a lower EC cell count compared to the control. Decreased EC counts were also observed in the jejunum and colon in both EA and sham treated groups; however, they were not significant except in the sham-treated colon. The present study demonstrated that in the normal guinea pigs electro-acupuncture on certain points tends to cause a decrease of the EC cell count in some parts of the gut; however, such results cannot be completely attributed to the effect of acupuncture.

Two and a half years of acupuncture in Alabama

From the data presented it appears that acupuncture helped in more than 50% of the patients by either completely or partially controlling pain from certain disorders. Patients helped by acupuncture received 8.55 treatments on the average, while patients not helped by acupuncture only received 4.75 treatments. There is difference between the male and female patients as to the response to acupuncture. However, we noticed that the younger the patient and the shorter the duration of their of problems, the better the response. Patients who had not had surgery to treat the pain syndrome responded better than those who had had previous surgery. Patients with backache who had previously had laminectomy showed better response to acupuncture than patients who had had spinal fusion. It appears that good general health plays an important role in favorable response to acupuncture treatment. Acupuncture may be a valuable extension of a conventional pain clinic and an alternative in patients who are desperate to obtain relief from pain which they failed to obtain from other methods.

Therapeutic effect of acupuncture for chronic pain

The purpose of this report concerned with the activities of the acupuncture clinic at UAB during the past 2 years and 3 months, is to objectively assess the role of acupuncture in the treatment of various pain disorders for which conventional pain relieving methods had failed to yield satisfactory results. In carefully analyzing the data provided by the patients through completed questionnaires, an attempt was made to look at the results obtained as unbiased as possible and to determine whether it is justified to continue the acupuncture activities at UAB or terminate them. From the data presented it appears that acupuncture helped in more than 50 percent of the patients by either completely or partially controlling the suffering from painful disorders. Patients helped by acupuncture received 8.55 treatments on the average, while patients not helped by acupuncture only received 4.75 treatments. There is little difference between the male and female patients as to the response to acupuncture. However, we noticed that the younger the patient and the shorter the duration of their problems, the better the response. Patients who had not had surgery to treat the pain syndrome responded better than those who had previous surgery. Patients with backache who had previously had laminectomy showed better response to acupuncture than the patients who had spinal fusion. It appears that good general health plays an important role in favorably responding to acupuncture treatment. It is apparent from this survey that acupuncture may be a valuable extension of a conventional pain clinic and an alternative in patients who are desperate in their desire to get relief from pain which they failed to obtain from other methods.

A new technique for the insertion of acupuncture needles

A new technique to insert acupuncture needles into the tissue without touching the needle with the fingers of the acupuncturist was developed by the authors. It is easy to perform and completely eliminates the problem of contamination. The bending of the needle is less frequent and the pain sensation of the patient is also minimized.

Caliber spectra of fibers in the fasciculus gracilis of the cat cervical spinal cord: a quantitative electron microscopic study

In order to obtain a better understanding of the microscopic structure of the cat fasciculus gracilis, entire cross-sections of the fasciculus were examined with the electron microscope. Twenty-five thousand, two hundred and eighty-four fibers were encountered in one fasciculus. The fiber caliber spectra obtained from the study show that the fasciculus gracilis at cervical level has a unique fiber distribution pattern. The fiber diameters range from less than 1 mu to 15 mu, however, 97 percent of fibers have diameters less than 8 mu; and the majority of the fibers are in the 2-5 mu range.