Non-cardiac comorbid health outcomes and prevalence after myocardial infarction: an umbrella review

OBJECTIVE

There exists limited comprehensive evidence on the potential association between non-cardiac comorbidities and myocardial infarction (MI). Thus, we conducted an umbrella review of existing meta-analyses to provide a broad understanding of non-cardiac health outcomes associated with MI.

MATERIALS AND METHODS

The primary focus on the prevalence of related health outcomes in patients with MI was systemically searched. Each original meta-analysis that was included had its methodological quality evaluated by a Measurement Tool Assessment Systematic Reviews 2 (AMSTAR2). To evaluate the certainty in the evidence for each outcome, we employed GRADE and the Joanna Briggs Institute Prevalence Critical Appraisal Tool. The protocol was registered in PROSPERO (CRD42023458642).

RESULTS

We identified seven meta-analyses comprising 126 studies with 336,581 participants from 22 countries and five continents. The pooled prevalence of comorbidities in patients with MI was 39% anxiety [95% confidence interval (CI), 30-48; GRADE, very low certainty], 29% depression (95% CI, 23-36; very low certainty), 39% frailty (95% CI, 24-55; very low certainty), and 23% failure of returning to work (95% CI, 16-29; very low certainty). The diagnosis of MI was associated with an increased risk of cognitive impairment (odds ratio, 1.45; 95% CI, 1.10-1.92; moderate certainty). Among frail patients, MI was associated with an increased risk of major bleeding (relative risk, 1.93; 95% CI, 1.08-3.45; low certainty) and mortality (relative risk, 2.29; 95% CI, 1.48-3.53; moderate certainty). However, we did not find any evidence of cancer risk associated with the development of MI.

CONCLUSIONS

Our umbrella meta-analysis provided comprehensive evidence of the association between MI and several non-cardiac health conditions. The robustness of our study is attributed to the integration of evidence across several studies, thus, these insights offer valuable treatment options for policymakers and physicians to develop personalized health strategies.

Phenolic changes in a combined herbal extract of Lithospermum erythrorhizon, Houttuynia cordata, and Spirodela polyrhiza and alleviation of DNCB-induced atopic dermatitis in BALB/c mice

Atopic dermatitis (AD) is an inflammatory skin disease showing skin barrier dysfunction, eczematous lesions, severe itching, and abnormal immune responses. The aim of this study was to determine whether an herb combination of Lithospermum erythrorhizon (LE), Houttuynia cordata (HC), and Spirodela polyrhiza (SP) has a superior anti-AD effect. Forty-two compounds were identified in LE, HC, SP, and a combined herb extract of LE, HC, and SP (LHS) using ultra-high-pressure liquid chromatography (UHPLC)-Orbitrap mass spectrometer (MS). The concentration of flavonoid glycosides including orientin (luteolin-8-C-glucoside), quercetin-3-O-rhamnoside, and luteolin-7-O-glucoside in the LHS was increased than in individual extracts. Furthermore, the treatment of LHS most effectively inhibited the increase of epidermal thickness, the number of mast cells, and the release of immunoglobulin E compared with that with each extract. These results suggest that the potential anti-AD effects of the LHS are due to the changes of bioactive compounds by the combination of herbs.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01329-7.

Umbelliferone Ameliorates Memory Impairment and Enhances Hippocampal Synaptic Plasticity in Scopolamine-Induced Rat Model

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by memory loss and cognitive decline. Among the suggested pathogenic mechanisms of AD, the cholinergic hypothesis proposes that AD symptoms are a result of reduced synthesis of acetylcholine (ACh). A non-selective antagonist of the muscarinic ACh receptor, scopolamine (SCOP) induced cognitive impairment in rodents. Umbelliferone (UMB) is a Apiaceae-family-derived 7-hydeoxycoumarin known for its antioxidant, anti-tumor, anticancer, anti-inflammatory, antibacterial, antimicrobial, and antidiabetic properties. However, the effects of UMB on the electrophysiological and ultrastructure morphological aspects of learning and memory are still not well-established. Thus, we investigated the effect of UMB treatment on cognitive behaviors and used organotypic hippocampal slice cultures for long-term potentiation (LTP) and the hippocampal synaptic ultrastructure. A hippocampal tissue analysis revealed that UMB attenuated a SCOP-induced blockade of field excitatory post-synaptic potential (fEPSP) activity and ameliorated the impairment of LTP by the NMDA and AMPA receptor antagonists. UMB also enhanced the hippocampal synaptic vesicle density on the synaptic ultrastructure. Furthermore, behavioral tests on male SD rats (7-8 weeks old) using the Y-maze test, passive avoidance test (PA), and Morris water maze test (MWM) showed that UMB recovered learning and memory deficits by SCOP. These cognitive improvements were in association with the enhanced expression of BDNF, TrkB, and the pCREB/CREB ratio and the suppression of acetylcholinesterase activity. The current findings indicate that UMB may be an effective neuroprotective reagent applicable for improving learning and memory against AD.

Ductal delivery of extracellular vesicles promote the recovery from salivary gland inflammation

Salivary gland dysfunction worsens the quality of life, but treatment for restoration of salivary gland function is limited. Although previous reports have demonstrated the therapeutic potentials of extracellular vesicles (EVs) in different preclinical models, the role of EVs in salivary glands remains elusive. Furthermore, little is known about the roles of salivary gland-derived EVs in tissue repair or regeneration compared to other EVs. In this study, EVs secreted from salivary gland-derived mesenchymal stem cells (sgMSCs) were comparatively analyzed with those from Wharton's jelly-derived MSC (wjMSCs). sgMSCs secreted more significant amounts of EVs than wjMSCs, and salivary gland epithelial cells showed a more efficient uptake of sgMSC-EVs than wjMSC-EVs. The possibility of immune regulation was tested via macrophage polarization and LPS-induced epithelial inflammation, resulting in an M1-to-M2 shift and reversal of acinar-to-ductal metaplasia by sgMSC-EV. Furthermore, the roles of sgMSC-EV-mediated immune regulation and tissue repair were clarified in vivo via retroductal delivery of sgMSC-EVs in a mouse model of obstructive sialadenitis. Collectively, our data demonstrate the superior role of sgMSC-EVs in the recovery from salivary gland inflammation and injury and suggest EVs as therapeutic tools for salivary gland dysfunction.

Naringin enhances long-term potentiation and recovers learning and memory deficits of amyloid-beta induced Alzheimer's disease-like behavioral rat model

Alzheimer's disease (AD), as the most typical type of dementia, is a chronic neurodegenerative disorder characterized by progressive learning and memory impairment. It is known that the main causes of AD are the accumulation of β-amyloid (Aβ) plaques and neurofibrillary tangles (NFT) containing hyperphosphorylated tau protein. Naringin is a flavonoid from citrus fruits, especially in grapefruit, which has anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective activities. However, the effect of naringin in AD caused by Aβ has not been clearly studied, and there are few studies on the electrophysiological aspect. Thus, we investigated the ex vivo neuroprotective effect of naringin through the long-term potentiation (LTP) on organotypic hippocampal slice cultures. We evaluated the in vivo effects of naringin (100 mg/kg/day) orally treated for 20 days on learning, memory, and cognition which was impaired by bilateral CA1 subregion injection of Aβ. Cognitive behaviors were measured 2 weeks after Aβ injection using behavioral tests and the hippocampal expression of apoptotic and neurotrophic regulators were measured by immunoblotting. In hippocampal tissue slices, naringin dose-dependently increased the field excitatory postsynaptic potential (fEPSP) after theta burst stimulation and attenuated Aβ-induced blockade of fEPSP in the hippocampal CA1 area. In Aβ injected rats, naringin improved object recognition memory in the novel object test, avoidance memory in the passive avoidance test and spatial recognition memory in the Morris water maze test. In the hippocampus, naringin attenuated the Aβ-induced cyclooxygenase-2, Bax activation and Bcl-2, CREB, BDNF and TrkB inhibition. These results suggest that naringin has therapeutic potential to reduce neuronal inflammation and apoptosis induced by Aβ related with the BDNF/TrkB/CREB signaling.

Salivary gland organoid culture maintains distinct glandular properties of murine and human major salivary glands

Salivary glands that produce and secrete saliva, which is essential for lubrication, digestion, immunity, and oral homeostasis, consist of diverse cells. The long-term maintenance of diverse salivary gland cells in organoids remains problematic. Here, we establish long-term murine and human salivary gland organoid cultures. Murine and human salivary gland organoids express gland-specific genes and proteins of acinar, myoepithelial, and duct cells, and exhibit gland functions when stimulated with neurotransmitters. Furthermore, human salivary gland organoids are established from isolated basal or luminal cells, retaining their characteristics. Single-cell RNA sequencing also indicates that human salivary gland organoids contain heterogeneous cell types and replicate glandular diversity. Our protocol also enables the generation of tumoroid cultures from benign and malignant salivary gland tumor types, in which tumor-specific gene signatures are well-conserved. In this study, we provide an experimental platform for the exploration of precision medicine in the era of tissue regeneration and anticancer treatment.

Thermoresponsive fiber-based microwells capable of formation and retrieval of salivary gland stem cell spheroids for the regeneration of irradiation-damaged salivary glands

Three-dimensional spheroid culture enhances cell-to-cell interactions among stem cells and promotes the expression of stem cell properties; however, subsequent retrieval and delivery of these cells remain a challenge. We fabricated a thermoresponsive fiber-based microwell scaffold by combining electrospinning and hydrogel micropatterning. The resultant scaffold appeared to facilitate the formation of cellular spheroids of uniform size and enabled the expression of more stem cell-secreting growth factor genes ( EGF, IGF-1, FGF1, FGF2, and HGF), pluripotent stem cell-related genes ( SOX2 and NANOG), and adult epithelial stem cell-related genes ( LGR4, LGR5, and LGR6) than salivary gland stem cells in a monolayer culture (SGSCmonolayer). The spheroids could be retrieved efficiently by decreasing temperature. SGSC-derived spheroid (SGSCspheroid) cells were then implanted into the submandibular glands of mice at 2 weeks after fractionated X-ray irradiation at a dose of 7.5 Gy/day. At 16 weeks post-irradiation, restoration of salivary function was detected only in SGSCspheroid-implanted mice. The production of submandibular acini specific mucin increased in SGSCspheroid-implanted mice, compared with PBS control. More MIST1+ mature acinar cells were preserved in the SGSCspheroid-implanted group than in the PBS control group. Intriguingly, SGSCspheroid-implanted mice exhibited greater amelioration of tissue damage and preservation of KRT7+ terminally differentiated luminal ductal cells than SGSCmonolayer-implanted mice. The SGSCspheroid-implanted mice also showed less DNA damage and apoptotic cell death than the SGSCmonolayer-implanted mice at 2 weeks post-implantation. Additionally, a significant increase in Ki67+AQP5+ proliferative acinar cells was noted only in SGSCspheroid-implanted mice. Our results suggest that a thermoresponsive fiber-based scaffold could be of use to facilitate the production of function-enhanced SGSCspheroid cells and their subsequent retrieval and delivery to damaged salivary glands to alleviate radiation-induced apoptotic cell death and promote salivary gland regeneration.

Retroductal Delivery of Epidermal Growth Factor Protects Salivary Progenitors after Irradiation

Salivary gland hypofunction after irradiation is associated with a deficit of epithelial stem/progenitors in salivary glands. Although epidermal growth factor (EGF) is known to stimulate the proliferation of epithelial cells, the therapeutic effect of EGF on salivary epithelial stem/progenitors remains undetermined. In this study, we administered EGF to submandibular glands (SMGs) via a retrograde route through the SMG excretory duct before fractionated irradiation and examined whether EGF could protect salivary epithelial progenitor cells from radiation and alleviate radiation-induced salivary hypofunction. EGF-treated mice exhibited greater body and gland weights at 12 wk after irradiation than untreated mice. The retroductal delivery of EGF improved salivary secretory function and increased salivary amylase activity in a dose-dependent manner. Histological examinations highlighted the amelioration of the loss of keratine-14⁺ (KRT14⁺) basal ductal and/or MIST1⁺ acinar cells, as well as induction of fibrosis, following irradiation in EGF-treated mice. An additional in vitro experiment using a salivary gland organoid irradiation model indicated that the radioprotective effects of EGF promoted the growth and inhibited the apoptotic cell death of salivary epithelial cells. Our results suggest that retroductal delivery of EGF may be a promising therapeutic option for preventing radiation-induced salivary gland hypofunction.

5-Fluorouracil as a Tumor-Treating Field-Sensitizer in Colon Cancer Therapy

Colorectal cancer (CRC) is a major cause of mortality that can be treated effectively with chemotherapy and radiotherapy, although resistance to these therapeutic modalities often occurs. Tumor-treating fields (TTFields) can block tumor growth by selectively impairing tumor cell division. In this study, we investigated the mechanism by which 5-fluorouracil (5-FU) sensitizes tumor cells to TTFields. Human HCT116 and SW480 CRC cells were treated with 5-FU and/or TTFields, and characterized in vitro in terms of cell viability, apoptosis through reactive oxygen species production, autophagy, and metastatic potentials. The biological effects of 5-FU and/or TTFields were studied via positron emission tomography and computed tomography on xenograft tumor growth and were confirmed with organoid models of patients. Our results revealed that combination treatment with 5-FU and TTFields increased the efficiency of TTFields therapy in colon cancer cells by downregulating signaling pathways associated with cell proliferation, survival, cell invasion, and migration while upregulating pathways mediating apoptosis and autophagic cell death. The novel mechanistic insights gleaned in this study suggest that combination therapy with TTFields and 5-FU may be effective in treating CRC, although safety and efficacy testing in patients with CRC will need to be performed before this strategy can be implemented clinically for TTF-sensitization.

Functional Biological Activity of Sorafenib as a Tumor-Treating Field Sensitizer for Glioblastoma Therapy

Glioblastoma, the most common primary brain tumor in adults, is an incurable malignancy with poor short-term survival and is typically treated with radiotherapy along with temozolomide. While the development of tumor-treating fields (TTFields), electric fields with alternating low and intermediate intensity has facilitated glioblastoma treatment, clinical outcomes of TTFields are reportedly inconsistent. However, combinatorial administration of chemotherapy with TTFields has proven effective for glioblastoma patients. Sorafenib, an anti-proliferative and apoptogenic agent, is used as first-line treatment for glioblastoma. This study aimed to investigate the effect of sorafenib on TTFields-induced anti-tumor and anti-angiogenesis responses in glioblastoma cells in vitro and in vivo. Sorafenib sensitized glioblastoma cells to TTFields, as evident from significantly decreased post-TTFields cell viability (p < 0.05), and combinatorial treatment with sorafenib and TTFields accelerated apoptosis via reactive oxygen species (ROS) generation, as evident from Poly (ADP-ribose) polymerase (PARP) cleavage. Furthermore, use of sorafenib plus TTFields increased autophagy, as evident from LC3 upregulation and autophagic vacuole formation. Cell cycle markers accumulated, and cells underwent a G2/M arrest, with an increased G0/G1 cell ratio. In addition, the combinatorial treatment significantly inhibited tumor cell motility and invasiveness, and angiogenesis. Our results suggest that combination therapy with sorafenib and TTFields is slightly better than each individual therapy and could potentially be used to treat glioblastoma in clinic, which requires further studies.

Xanthohumol prevents dextran sulfate sodium-induced colitis via inhibition of IKKβ/NF-κB signaling in mice

Xanthohumol (XN), a prenylated chalcone isolated from the hop plant, has been reported to exhibit multiple biological functions including anti-inflammation. However, the pharmacological function of XN on colitis remains unknown. In this study, we investigated the anti-inflammatory effect of synthesized XN and molecular mechanism on dextran sulfate sodium (DSS)-induced experimental colitis. XN attenuated the colitis symptoms along with the prevention of colonic lesions after DSS challenge. XN inhibited the production of pro-inflammatory cytokines, oxidative stress and cyclooxygenase-2 expression in DSS-treated mice. Moreover, XN inhibited the phosphorylation of IκBα, the nuclear translocation of NF-κB subunits and the transcriptional activity of NF-κB in vivo and in vitro. In contrast to XN, isoXN showed much less effects on the kinase activity of IKKβ and IκBα phosphorylation induced by XN in this study, suggesting that an electrophilic carbon center present in XN is critical for the anti-inflammation in colitis, especially inhibition of IKKβ/NF-κB signaling pathway. Consistently, our docking analysis revealed that XN could bind to the active site, presumably at the Cys99 of IKKβ. Taken together, these findings demonstrate a new function of XN to inhibit IKKβ/NF-κB signaling, suggesting XN could be the potential therapeutic agent for the prevention of colitis.

Protective Effect of Boiled and Freeze-dried Mature Silkworm Larval Powder Against Diethylnitrosamine-induced Hepatotoxicity in Mice

Background

Hepatocellular carcinoma (HCC) is a representative inflammation-associated cancer and known to be the most frequent tumors. HCC may also induce important pro- and anti-tumor immune reactions. However, the underlying mechanisms are unsatisfactorily identified. We investigated the protective effect of boiled and freeze-dried mature silkworm larval powder (BMSP) on diethylnitrosamine (DEN)-induced hepatotoxicity in mice.

Methods

Mice were fed with diet containing BMSP (0.1, 1, and 10 g/kg) for two weeks and DEN (100 mg/kg, intraperitoneally) was injected 18 hours before the end of this experiment. Liver toxicity was determined in serum and histopathological examination was assessed in the liver tissues. Infiltration of immune cells and expressions of inflammatory cytokines and chemokines were also examined.

Results

Pretreatment with BMSP reduced necrotic and histopathological changes induced by DEN in the liver. Measurement of serum biochemical indicators, the levels of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase, showed that pretreatment with BMSP also decreased DEN-induced hepatotoxicity. In addition, BMSP inhibited the macrophage and CD31 infiltration in a dose-dependent manner. The expressions of interleukin-1β, IFN-γ and chemokines for T cell activation were decreased in BMSP pretreatment groups.

Conclusions

BMSP may have a protective effect against acute liver injury by inhibiting necrosis and inflammatory response in DEN-treated mice.

Suppurative meckel diiverticulum in a 3-year-old girl presenting with periumbilical cellulitis

Meckel diverticulum (MD) is one of the most common congenital gastrointestinal anomalies and occurs in 1.2-2% of the general population. MD usually presents with massive painless rectal bleeding, intestinal obstruction or inflammation in children and adults. Suppurative Meckel diverticulitis is uncommon in children. An experience is described of a 3-year-old girl with suppurative inflammation in a tip of MD. She complained of acute colicky abdominal pain, vomiting and periumbilical erythema. Laparoscopic surgery found a relatively long MD with necrotic and fluid-filled cystic end, which was attatched to abdominal wall caused by inflammation. Herein, we report an interesting and unusual case of a suppurative Meckel diverticulitis presenting as periumbilical cellulitis in a child. Because of its varied presentations, MD might always be considered as one of the differential diagonosis.

Comparison of alfuzosin 10 mg with or without propiverine 10 mg, 20 mg in men with lower urinary tract symptom and an overactive bladder: randomised, single-blind, prospective study

PURPOSE

The efficacy and safety of treatment with alfuzosin 10 mg plus propiverine 10 or 20 mg in men with lower urinary tract symptoms (LUTS) and an overactive bladder were investigated.

MATERIALS AND METHODS

In this parallel-arm, prospective, multicentre, single-blind study, men who were ≥ 40 years old, had an International Prostate Symptom Score (IPSS) of ≥ 8, an Overactive Bladder Symptom Score (OABSS) of ≥ 3 and an OABSS urgency item score of ≥ 2 were randomised in a 1 : 1 :1 ratio to receive alfuzosin 10 mg alone (Group A) or with propiverine 10 mg (Group B) or 20 mg (Group C) for 8 weeks. Four and 8 weeks after commencing treatment, OABSS was measured along with IPSS, maximal urinary flow rate (Qmax ) and postvoid residual volume (PVR). Adverse events were recorded.

RESULTS

A total of 135 men, including 43 in Group A, 48 in Group B and 44 in Group C, completed the study. Relative to baseline, all groups demonstrated significant reductions in OABSS and the IPSS after eight treatment weeks (p < 0.005). The improvement of OABSS in Group C was significantly greater than Group A and B (Group A: 0.70 ± 1.94; Group B: 2.50 ± 2.98; Group C: 4.30 ± 3.40; p < 0.005). An observed improvement of Qmax and PVR in the three groups did not achieve statistical significance. Overall adverse event rates were higher in Group C but not significant compared with others.

CONCLUSION

In patients with LUTS and overactive bladder, combined therapy with alfuzosin 10 mg plus propiverine 20 mg was significantly more effective than alfuzosin monotherapy and propiverine 10 mg combined therapy in terms of improving OABSS while not significantly affecting Qmax or PVR.

Preliminary study for gait phases detection to develop a rehabilitation equipment for hemiplegic patients

Preliminary experiment for analyzing weight shift during gait phases for hemiplegic patients was carried out to develop rehabilitation equipment. A gait phase detection system using pressure sensors was developed and the experiment was carried out for eight hemiplegic patients and normal adult. The weight shift during gait phases for a normal adult showed symmetrical for left and right footing phase, but that for the hemiplegic patients showed asymmetrical footing phase. However, it gave sufficient information to discriminate between left and right footing phases.

Comparison of efficacy for erectile function and lower urinary tract symptoms of tadalafil 20 mg on-demand and 5 mg once daily in patients with erectile dysfunction

Aim:  To compare the improvement in erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) as well as safety of tadalafil dosed at 20 mg on-demand and 5 mg once daily among ED patients. Materials and methods:  A total of 194 ED patients visited between March 2010 and June 2011 were recruited. Out of 194 individuals, 168 (86.6%) met inclusion criteria after completing the two-week screening period (V0). The Patients were randomly allocated into two groups: (i) 20 mg of tadalafil as needed (Group 1: n = 84, 50.0%) and (ii) 5 mg of tadalafil once daily (Group 2: n = 84, 50.0%). Blood pressure (BP), heart rate (HR) and the five-item version of the International Index of Erectile Function (IIEF-5) were assessed immediately before initiation of treatment (V1) and after four (V2) and twelve weeks of treatment (V3). In men with an IPSS of ≥ 8 at V1, IPSS, maximal flow rate (Qmax) and post-void residual volume (PVR) were also assessed. Results:  Of the 168 patients, 134 (79.8%; Group 1: n = 68, 81.0%; Group 2: n = 66, 78.6%) patients completed the trial. IIEF-5 improved in both groups, and the mean change was larger in Group 2 at V3 (4.9 ± 4.2 vs. 6.5 ± 4.5; p = 0.032) Similarly, though IPSS (with ≥ 8, n = 88, 65.7%; Group 1: n = 44, 64.7%; Group 2: n = 44, 66.7%) improved in both groups, the mean change was larger in Group 2 at V3 (-2.8 ± 4.3 vs. -4.8 ± 4.1; p = 0.026). Qmax and PVR did not differ significantly in either group. Conclusions:  Once daily tadalafil was more efficacious in treating both ED and LUTS than on-demand dosing. However, no differences were observed between the two dosing schedules with regard to the improvement in LUTS when stratified by improvement in ED. The side effects were insignificant for both dosing schedules.

Contrast-enhanced MR cholangiography: comparison of Gd-EOB-DTPA and Mn-DPDP in healthy volunteers

OBJECTIVE

The purpose of this study was to compare the biliary enhancement dynamics of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) and mangafodipir trisodium (Mn-DPDP) for contrast-enhanced MR cholangiography (MRC) in healthy subjects.

METHODS

15 healthy volunteers underwent MRI at 1.5 T with volumetric interpolated breath-hold examination sequence. Each volunteer was scanned once for each contrast agent. The signal-to-noise ratio (SNR) of the liver parenchyma and common hepatic duct (CHD) and the contrast-to-noise ratio (CNR) of CHD to liver parenchyma were evaluated and compared before and at several time points (5, 15, 30, 45, 60, 90, and 120 min) after injection of each agent.

RESULTS

SNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP in liver parenchyma after 5 min and in CHD after 15 min (p<0.05). CNR of CHD to liver parenchyma using Gd-EOB-DTPA showed an initial decrease at 5 min post-injection followed by a steep increase to a peak at 15 min post-injection. CNR using Mn-DPDP showed a steady increase to a peak at 15 min post-injection without an initial decrease. At 15 min, the value of CNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP (p<0.05).

CONCLUSION

For both contrast agents, CNR reached a peak at 15 min after contrast injection. At this time point, CNR of Gd-EOB-DTPA was significantly higher than that of Mn-DPDP. Therefore, Gd-EOB-DTPA may provide better contrast-enhanced MRC than Mn-DPDP at 15 min after contrast administration.

De novo autoimmune hepatitis in Korean children after liver transplantation: a single institution's experience

INTRODUCTION

De novo autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLT) has been described as a new type of late graft dysfunction in children who have not undergone transplantation for previous autoimmune liver disease. The purpose of this study was to evaluate the clinical aspects of de novo AIH among children following OLT.

PATIENTS AND METHODS

Between January 1994 and May 2007, 149 children underwent OLT, including 1 with recurrent AIH who was excluded from this study, whereas 4 others developed de novo AIH (2.7%; n = 4/148). We analyzed the demographics, laboratory characteristics, and response to treatment of the 4 children with de novo AIH following OLT.

RESULTS

The 4 patients were all girls with a median interval after OLT to presentation of 6.5 years (range, 0.7-8.8 years). The median age when de novo AIH developed was 12.4 years (range, 8.7-17.3 years). All cases were detected by abnormal liver function tests, namely, increased aspartate aminotransferase (AST; median, 322 IU/L; range, 181-919 IU/L). One patient showed elevated immunoglobulin G. Three patients displayed positive antinuclear antibodies. All were seronegative for smooth muscle antibody and liver-kidney microsomal type 1 antibody. One patient showed anti-mitochondrial antibody. All patients were treated with steroids with or without azathioprine. The liver function tests in these 4 patients, improved by at least 50% during the first month of treatment, responding to steroid treatment with or without azathioprine.

CONCLUSION

In preadolescent or adolescent female patients with unexplained graft dysfunction after OLT, it is important to recognize de novo AIH rapidly and to develop an adequate diagnostic strategy, including evaluation of serum autoantibodies, immunoglobulin G, and liver biopsy.

A diagnosis system for the spinal column nerve damaged patients

Visible evidence of spinal column damage is only apparent in 14% of the patients who receive spinal damage. We use a humidity sensor array. The humidity sensor (HDP-05) is arranged and attached to pre-assigned regions along the spinal column nerve of the actual patient. Applying pressure to the urinary bladder causes the patient to sweat. It is possible to determine which spinal column autonomic nerve is damaged in a region by humidity value. But also have some problem is that sometimes the damaged region has same value as a normal region. If will find a better attachment method and a more sensitive sensor could be found the results will be better and more precise.

Overexpression of SERTAD3, a putative oncogene located within the 19q13 amplicon, induces E2F activity and promotes tumor growth

The amplified region of chromosome 19q13.1-13.2 has been associated with several cancers. The well-characterized oncogene AKT2 is located in this amplicon. Two members of the same gene family (SERTAD1 and SERTAD3) are also located within this region. We report herein the genomic structure and potential functions of SERTAD3. SERTAD3 has two transcript variants with short mRNA half-lives, and one of the variants is tightly regulated throughout G1 and S phases of the cell cycle. Overexpression of SERTAD3 induces cell transformation in vitro and tumor formation in mice, whereas inhibition of SERTAD3 by small interfering RNA (siRNA) results in a reduction in cell growth rate. Furthermore, luciferase assays based on E2F-1 binding indicate that SERTAD3 increases the activity of E2F, which is reduced by inhibition of SERTAD3 by siRNA. Together, our data support that SERTAD3 contributes to oncogenesis, at least in part, via an E2F-dependent mechanism.

Phosphodiesterase: overview of protein structures, potential therapeutic applications and recent progress in drug development

Phosphodiesterases (PDEs) are essential regulators of cyclic nucleotide signaling with diverse physiological functions. Because of their great market potential and therapeutic importance, PDE inhibitors became recognized as important therapeutic agents in the treatment of various diseases. Currently, there are seven PDE inhibitors on the market, and the pharmacological and safety evaluations of many drug candidates are in progress. Three-dimensional (3D) structures of catalytic domains of PDE 1, -3, -4, -5 and -9 in the presence of their inhibitors are now available, and can be utilized for rational drug design. Recent advances in molecular pharmacology of PDE isoenzymes resulted in identification of new potential applications of PDE inhibitors in various therapeutic areas, including dementia, depression and schizophrenia. This review will describe the latest advances in PDE research on 3D structural studies, the potential of therapeutic applications and the development of drug candidates.

Folding and stability of sweet protein single-chain monellin. An insight to protein engineering

Engineered single-chain monellin (SCM) proteins were constructed by recombinant technology without disrupting the topology and sweet activity of native protein. Data from 8-anilinonaphthalene-1-sulfonic acid fluorescence, size-exclusion chromatography, and heteronuclear NMR strongly suggest the presence of a folding intermediate at 1.5 m GdnHCl for SCM protein. The structural feature of the folding intermediate from NMR data reveals that the secondary structures became mostly unstable, and protein experiences a dynamic equilibrium between native and unfolded state. All backbone amide protons exchange within 10 min, which imply that no stable hydrogen bonds exist in the secondary structural regions in the folding intermediate. From equilibrium unfolding and mutagenesis studies, the unfolding transition midpoints of mutant proteins gradually shifted toward lower denaturant concentration, indicating stability reductions of mutant proteins. Our results suggest that stability and folding pathways of SCM proteins could be regulated by a combined study of spectroscopy and mutagenesis, and these studies will provide useful information for understanding the folding kinetics of novel engineered proteins.

Detection of hepatocellular carcinoma: combined T2-weighted and dynamic gadolinium-enhanced MRI versus combined CT during arterial portography and CT hepatic arteriography

PURPOSE

The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

METHOD

Thirty-three patients with 43 HCCs underwent T2-weighted and dynamic gadolinium-enhanced MRI and combined CTAP and CTHA. The diagnosis was established by pathologic examination following surgical resection in 26 patients and by biopsy in 7 patients. The MR protocol included fast SE with two TEs (including T2-weighted imaging) and precontrast and gadolinium-enhanced T1-weighted fast multiplanar spoiled gradient-recalled echo images with dynamic study. The MR images of all sequences and the paired CTAP and CTHA images were independently reviewed by three radiologists. Image review was conducted on a segment-by-segment basis. Diagnostic accuracy was evaluated with receiver operating characteristic analysis.

RESULTS

The accuracies (Az values) of MRI of all sequences and combined CTAP and CTHA for all observers were 0.960 and 0.959, respectively. The mean sensitivities of MRI and CT were 90 and 94%, respectively. The differences were not statistically significant. The mean specificity of MRI (99%) was significantly higher than that of combined CTAP and CTHA (92%).

CONCLUSION

Combined T2-weighted and dynamic gadolinium-enhanced MRI is as accurate as combined CTAP and CTHA for preoperative detection of HCCs.

Solution structure, backbone dynamics, and stability of a double mutant single-chain monellin. structural origin of sweetness

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has been characterized as being as sweet as native two-chain monellin. Data from gel-filtration high performance liquid chromatography and NMR has proven that SCM exists as a monomer in aqueous solution. In order to determine the structural origin of the taste of sweetness, we engineered several mutant SCM proteins by mutating Glu(2), Asp(7), and Arg(39) residues, which are responsible for sweetness. In this study, we present the solution structure, backbone dynamics, and stability of mutant SCM proteins using circular dichroism, fluorescence, and NMR spectroscopy. Based on the NMR data, a stable alpha-helix and five-stranded antiparallel beta-sheet were identified for double mutant SCM. Strands beta1 and beta2 are connected by a small bulge, and the disruption of the first beta-strand were observed with SCM(DR) comprising residues of Ile(38)-Cys(41). The dynamical and folding characteristics from circular dichroism, fluorescence, and backbone dynamics studies revealed that both wild type and mutant proteins showed distinct dynamical as well as stability differences, suggesting the important role of mutated residues in the sweet taste of SCM. Our results will provide an insight into the structural origin of sweet taste as well as the mutational effect in the stability of the engineered sweet protein SCM.

Non-combustible waste vitrification with plasma torch melter

Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column

This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000-2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water.

Expression and purification of an active, full-length hepatitis C viral NS4A

The nonstructural protein 3 (NS3) of the hepatitis C virus (HCV) is a bifunctional protein with protease and helicase activities. Nonstructural protein 4A (NS4A) is preceded by NS3 and augments the proteolytic activity of NS3 through protein-protein interaction. The central domain of NS4A has been shown to be sufficient for the enhancement of the NS3 protease activity. However, investigations on the roles of the N-terminal and the C-terminal regions of NS4A have been hampered by the difficulty of purification of full-length NS4A, a polypeptide that contains highly hydrophobic amino acid residues. Here we report a procedure by which one can produce and purify an active, full-length NS4A using maltose-binding protein fusion method. The full-length NS4A fused to the maltose binding protein is soluble and maintains its NS3 protease-enhancing activity.

RBT1, a novel transcriptional co-activator, binds the second subunit of replication protein A

Replication Protein A (RPA) is required for DNA recombination, repair and replication in all eukaryotes. RPA participation in these pathways is mediated by single-stranded DNA binding and protein interactions. We herein identify a novel protein, Replication Protein Binding Trans-Activator (RBT1), in a yeast two-hybrid assay employing the second subunit of human RPA (RPA32) as bait. RBT1-RPA32 binding was confirmed by glutathione S:-transferase pull-down and co-immunoprecipitation. Fluorescence microscopy indicates that green fluorescence protein-tagged RBT1 is localized to the nucleus in vivo. RBT1 mRNA expression, determined by semi-quantitative RT-PCR, is significantly higher in cancer cell lines MCF-7, ZR-75, SaOS-2 and H661, compared to the cell lines normal non-immortalized human mammary epithelial cells and normal non-immortalized human bronchial epithelial cells. Further, yeast and mammalian one-hybrid analysis shows that RBT1 is a strong transcriptional co-activator. Interestingly, mammalian transactivation data is indicative of significant variance between cell lines; the GAL4-RBT1 fusion protein has significantly higher transcriptional activity in human cancer cells compared to human normal primary non-immortalized epithelial cells. We propose that RBT1 is a novel transcriptional co-activator that interacts with RPA, and has significantly higher activity in transformed cells.

Needle-tract implantation in hepatocellular carcinoma: frequency and CT findings after biopsy with a 19.5-gauge automated biopsy gun

BACKGROUND

Needle-tract implantation is an important complication of cutting biopsy of hepatocellular carcinoma (HCC). This study was performed to evaluate the frequency of needle-tract implantation after ultrasound (US)-guided percutaneous biopsy of HCC and to describe triple-phase helical computed tomographic (CT) findings of implanted nodules.

METHODS

Between April 1994 and December 1997, 205 patients underwent US-guided percutaneous biopsy for HCC. Review of medical records and the pathology database disclosed seven patients who were found to have needle-tract implantation of HCC. Among these patients, five underwent triple-phase helical CT examination. We analyzed the frequency of needle-tract implantation and triple-phase helical CT findings of implanted nodules, with particular attention to the morphology and enhancement pattern.

RESULTS

Seven of 205 patients (3.4%) had tumor implantation along the needle tract at histologic examination after surgical resection. Eight implanted nodules in five patients were found on triple-phase helical CT images (one nodule in three patients, two nodules in one patient, and three nodules in one patient). All implanted nodules has well-circumscribed margins and were ovoid or lobulated in contour. On triple-phase helical CT, six (75%) implanted nodules were isodense compared with abdominal wall muscle on all triple-phase CTs, and two (25%) nodules were hyperdense on hepatic arterial and portal venous phases and isodense on equilibrium phase.

CONCLUSIONS

The frequency of needle-tract implantation of HCC after percutaneous needle biopsy was higher than reported previously, and careful attention should be paid during interpretation of CT images in patients with a history of previous percutaneous biopsy.

Dysplastic nodules in liver cirrhosis: evaluation of hemodynamics with CT during arterial portography and CT hepatic arteriography

PURPOSE

To evaluate the portal and arterial blood supplies to dysplastic nodules in the cirrhotic liver with computed tomography (CT) during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

MATERIALS AND METHODS

Nineteen histopathologically proved low-grade dysplastic nodules and 13 high-grade dysplastic nodules in 17 patients with liver cirrhosis were evaluated with CTAP and CTHA for the presence of portal and arterial blood supplies to the nodules. The nodules ranged from 0.4 to 4.5 cm in diameter (mean, 1.6 cm).

RESULTS

The portal supply was present in 14 of the 19 (74%) low-grade dysplastic nodules and in seven of the 13 (54%) high-grade dysplastic nodules. The hepatic arterial supply was increased in four of the 19 (21%) low-grade dysplastic nodules, present in nine (47%), and absent in six (32%). The arterial supply was increased in four of the 13 (31%) high-grade dysplastic nodules, present in four (31%), and absent in five (38%).

CONCLUSION

The portal and arterial supplies to the low- and high-grade dysplastic nodules were variable and inconsistent. Therefore, it is difficult to detect and characterize the dysplastic nodules on the radiologic images on the basis of the blood supply.

Functional MR imaging of working memory in the human brain

OBJECTIVE

In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed.

MATERIALS AND METHODS

In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p <.001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks.

RESULTS

The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere.

CONCLUSION

The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

Salivary gland tumors: evaluation with two-phase helical CT

PURPOSE

To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors.

MATERIALS AND METHODS

Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning.

RESULTS

There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors.

CONCLUSION

The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM

The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features.

MATERIALS AND METHODS

Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features.

RESULTS

On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable.

CONCLUSION

Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.

Primary mucinous cystadenocarcinoma of the appendix: CT findings

OBJECTIVE

The preoperative diagnosis of a primary appendiceal tumor can be difficult because of its rarity and the paucity of material in the radiology literature. The purpose of this study was to describe CT findings in six patients with primary mucinous cystadenocarcinoma of the appendix.

CONCLUSION

When CT reveals a cystic mass with enhancing wall nodularity in the expected area of the appendix, especially in older patients, the possibility of primary mucinous cystadenocarcinoma should be considered.

Variations in meniscofemoral ligaments at anatomical study and MR imaging

PURPOSE

To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging.

DESIGN

Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus.

RESULTS

At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27.

CONCLUSION

An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies.

Solution structure of a sweet protein single-chain monellin determined by nuclear magnetic resonance and dynamical simulated annealing calculations

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has proven to be as sweet as native two-chain monellin. SCM is more stable than the native monellin for both heat and acidic environments. Data from gel filtration HPLC and NMR indicate that the SCM exists as a monomer in aqueous solution. The solution structure of SCM has been determined by nuclear magnetic resonance (NMR) spectroscopy and dynamical simulated annealing calculations. A stable alpha-helix spanning residues Phe11-Ile26 and an antiparallel beta-sheet formed by residues 2-5, 36-38, 41-47, 54-64, 69-75, and 83-88 have been identified. The sheet was well defined by backbone-backbone NOEs, and the corresponding beta-strands were further confirmed by hydrogen bond networks based on amide hydrogen exchange data. Strands beta2 and beta3 are connected by a small bulge comprising residues Ile38-Cys41. A total of 993 distance and 56 dihedral angle restraints were used for simulated annealing calculations. The final simulated annealing structures (<SA>k) converged well with a root-mean-square deviation (rmsd) between backbone atoms of 0.49 A for secondary structural regions and 0.70 A for backbone atoms excluding two loop regions. The average restraint energy-minimized (REM) structure exhibited root-mean-square deviations of 1.19 A for backbone atoms and 0.85 A for backbone atoms excluding two loop regions with respect to 20 <SA>k structures. The solution structure of SCM revealed that the long alpha-helix was folded into the concave side of a six-stranded antiparallel beta-sheet. The side chains of Tyr63 and Asp66 which are common to all sweet peptides showed an opposite orientation relative to H1 helix, and they were all solvent-exposed. Residues at the proposed dimeric interface in the X-ray structure were observed to be mostly solvent-exposed and demonstrated high degrees of flexibility.

A peptide from hog plasma that inhibits human cholesteryl ester transfer protein

A peptide that inhibits the human cholesteryl ester transfer protein (CETP) was isolated from hog plasma by ultracentrifugation, two sequential column chromatographies and electroelution from gels. Molecular weight of the peptide was determined to be approximately 3 kDa on the SDS-PAGE. The peptide contained 28 amino acids with an identical sequence to the amino terminus of hog apolipoprotein-CIII except two amino acid residues: -Pro-Glu- at the fifth and sixth amino acids from the amino terminus in the isolated peptide, in contrast to -Leu-Leu- in hog apo-CIII. A peptide synthesized chemically according to the amino acid sequence of the peptide (designated P28) showed approximately the same degree of CETP inhibitory activity as the isolated peptide. Synthetic peptides with different number of amino acids were also tested for CETP inhibition. Among the peptides, the one with 20 amino acid residues (P20) from the amino terminus showed the highest inhibitory activity against the CETP. The peptide appeared to be associated with the hog high-density lipoproteins (HDL), as determined by immunoblot analysis using antibody against P28. The CETP-inhibitory activity of the peptide was examined in vivo using diet-induced hypercholesterolemic rabbits. When the peptide was injected into the rabbits (7-9 mg/kg body weight), approximately 75% CETP activity disappeared from the plasma in 1 h after the injection and the effect lasted up to 30 h. The inhibition of CETP in vivo led to a concomitant decrease in total plasma cholesterol level up to 30% and an increase in the level of HDL-cholesterol up to 32%. The cholesterol concentrations in the rabbit plasma gradually recovered to the initial level after 48 h.

Molecular cloning of a novel ubiquitin-specific protease, UBP41, with isopeptidase activity in chick skeletal muscle

A cDNA encoding a new ubiquitin-specific protease, UBP41, in chick skeletal muscle was cloned using an Escherichia coli-based in vivo screening method. Nucleotide sequence analysis of the cDNA containing an open reading frame of 1,071 base pairs revealed that the protease consists of 357 residues with a calculated molecular mass of 40,847 Da, and is related to members of the UBP family containing highly conserved Cys and His domains. Chick UBP41 was expressed in E. coli and purified from the cells to apparent homogeneity, using 125I-labeled ubiquitin-alphaNH-MHISPPEPESEEEEEHYC as a substrate. The purified enzyme behaved as an approximately 43-kDa protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. Like other deubiquitinating enzymes, it was sensitive to inhibition by ubiquitin-aldehyde and sulfhydryl blocking agents, such as N-ethylmaleimide. The UBP41 protease cleaved at the C terminus of the ubiquitin moiety in natural and engineered fusions irrespective of their sizes; thus, it is active against ubiquitin-beta-galactosidase as well as ubiquitin C-terminal extension protein of 80 amino acids. UBP41 also released free ubiquitin from poly-His-tagged di-ubiquitin. Moreover, it converted poly-ubiquitinated lysozyme conjugates to mono-ubiquitinated forms of about 24 kDa, although the latter molecules were not further degraded to free ubiquitin and lysozyme. These results suggest that UBP41 may play an important role in the recycling of ubiquitin by hydrolysis of branched poly-ubiquitin chains generated by the action of 26 S proteasome on poly-ubiquitinated protein substrates, as well as in the production of free ubiquitin from linear poly-ubiquitin chains and of certain ribosomal proteins from ubiquitin fusion proteins.

Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen

Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

Viral loads and E2/NS1 region sequences of hepatitis C virus in hepatocellular carcinoma and surrounding liver

OBJECTIVES

Numerous epidemiologic data have documented that chronic infection by hepatitis C virus (HCV) is a major risk factor for the development of hepatocellular carcinoma (HCC). But the molecular mechanism underlying these strong epidemiologic associations between HCV and HCC has not be elucidated. We observed the changes of HCV in HCC to investigate the association of HCV with HCC.

METHODS

We used competitive and quantitative polymerase chain reaction and dideoxy-nucleotide chain termination method to compare HCV titers and sequences of the hypervariable region of E2/NS1 region of four isolates from the HCC and surrounding cirrhotic liver tissues in tow anti-HCV positive patients.

RESULTS

The copy numbers of HCV-RNA were 1 x 10(6) and 4 x 10(6)/gm wet weight of HCC, and 8 x 10(7) and 3.2 x 10(8)/gm wet weight of cirrhotic liver tissues from patient-1 and -2. The sequence differences between HCV RNA in HCC and in cirrhotic liver were two and five nucleotides in patient-1 and in patient-2 respectively. The amino acid sequences were changed in one and two site in each patient.

CONCLUSION

These findings may suggest the possible etiological role of HCV in carcinogenesis of HCC, but complete sequence analysis of HCV including multiple isolates in the same patient, should be performed in many cases.