ABSTRACT
Environmental pollution mitigation measure involving bioremediation technology is a sustainable intervention for a greener ecosystem biorecovery, especially the obnoxious hydrocarbons, xenobiotics, and other environmental pollutants induced by anthropogenic stressors. Several successful case studies have provided evidence to this paradigm including the putative adoption that the technology is eco-friendly, cost-effective, and shows a high tendency for total contaminants mineralization into innocuous bye-products. The present review reports advances in bioremediation, types, and strategies conventionally adopted in contaminant clean-up. It identified that natural attenuation and biostimulation are faced with notable limitations including the poor remedial outcome under the natural attenuation system and the residual contamination occasion following a biostimulation operation. It remarks that the use of genetically engineered microorganisms shows a potentially promising insight as a prudent remedial approach but is currently challenged by few ethical restrictions and the rural unavailability of the technology. It underscores that bioaugmentation, particularly the use of high cell density assemblages referred to as microbial consortia possess promising remedial prospects thus offers a more sustainable environmental security. The authors, therefore, recommend bioaugmentation for large scale contaminated sites in regions where environmental degradation is commonplace.
Subject(s)
Environmental Restoration and Remediation , Petroleum , Soil Pollutants , Anthropogenic Effects , Biodegradation, Environmental , Ecosystem , Hydrocarbons , Soil Microbiology , Soil Pollutants/analysis , TechnologyABSTRACT
The KANNO blood group system (International Society of Blood Transfusion [ISBT] 037) includes one high-prevalence antigen, KANNO1, across ethnic groups. Sporadic KANNO1- cases among East and South Asians are theoretically estimated by the DNA database library. Anti-KANNO1 has been found most often among Japanese women with current or prior pregnancy. Thus far, there are no reported cases of hemolytic transfusion reaction or hemolytic disease of the fetus and newborn due to anti-KANNO1.
Subject(s)
Blood Group Antigens , Erythroblastosis, Fetal , Transfusion Reaction , Pregnancy , Infant, Newborn , Humans , Female , Blood Transfusion , Hemolysis , Erythroblastosis, Fetal/therapyABSTRACT
BACKGROUND: A small accessory facet with articular surface morphology is occasionally seen on the talus, bordering on the lateral end of the sinus tarsi. This facet has been named the accessory anterolateral talar facet. However, few anatomical studies have addressed this facet. Here we present the precise morphology of accessory anterolateral talar facet with emphasis on anatomical correlation between the presence of this facet and the angle of the infero-lateral surface of the talus (talar infero-lateral surface - TILS angle). MATERIALS AND METHODS: A total of 22 (11 male, 11 female) adult cadavers with no known pathological conditions in the talocalcaneal joints were examined during educational dissection at Nagoya City University Medical School in 2013. After exclusion of 1 joint due to the poor condition of the talus, 43 talus (22 right, 21 left) were analysed. We judged the presence of the accessory anterolateral talar facet and measured TILS angle. We performed statistical analysis on the point of laterality, gender difference and the difference in the TILS angles in tali with or without the accessory anterolateral talar facets. RESULTS: An accessory anterolateral talar facet was identified in 11 (26%) of the 43 specimens. Of the 21 cadavers with paired talar specimens, 5 displayed the facet bilaterally. CONCLUSIONS: There was no sex difference and no significant laterality, however we found that TILS angle was significantly larger in accessory anterolateral talar facet positive samples than in negative ones.
ABSTRACT
BACKGROUND: The articularis genus muscle pulls the suprapatellar pouch upwards when the knee joint is extended, preventing mechanical impingement of the joint capsule which theoretically could cause anterior knee pain. However, few anatomical studies have addressed this muscle. Here we present the precise morphology of articularis genus. MATERIALS AND METHODS: A total of 22 (13 male and 9 female) adult cadavers with no pathological conditions in the knee joints were examined during educational dissection at Nagoya City University Medical School in 2012. After exclusion of 4 joints due to their flexion contracture, 40 knee joints (18 right and 22 left) were analysed. We performed statistical analysis on anatomical laterality and the difference of sizes among lateral, medial and central branches and studied the correlation of the length and area of the articularis genus muscle to the lengthand cross-section area of the femur. RESULTS AND CONCLUSIONS: The average number of branches of the deep layer of the articularis genus muscle was 2.7 ± 0.5, the mean length of all brancheswas 5.4 ± 1.3 cm and the mean area of all branches was 5.5 ± 2.6 cm². There was no significant correlation between the length and area of the articularis genus muscle to the length and cross-section area of the femur. There was no significant laterality in central, medial and lateral branches; however we found that the medial branch was statistically longer and larger than the lateral branchon either knee. This could be contributing to prevention of lateral dislocation of the patella.
ABSTRACT
BACKGROUND: The Human Fertilization and Embryology Authority is considering limiting the number of embryos that can be transferred to single embryo per cycle as has been done in several European countries, with the aim of reducing the rate of multiple pregnancies and its attendant complications following in vitro fertilization (IVF) / Intracytoplasmic sperm injection (ICSI). OBJECTIVE: To determine the number of embryos patients' attending a fertility clinic in Nigeria, would prefer transferred during IVF/ICSI. MATERIALS AND METHODS: Fifty four consecutive female patients who underwent IVF/ICSI procedures between May 2006 and April 2007 at the Port Harcourt Fertility Centre, Rivers State were interviewed using structured questionnaires. They were informed of all the obstetric and perinatal complications of multiple pregnancies and the advantages and trend towards single embryo transfer and then asked to choose the number of embryos (one, two or three) they would prefer transferred assuming similar implantation rates. Each respondent was allowed to give reason(s) for their choice. DESIGN: Prospective, descriptive study. RESULTS: Fifty one (94.4%) of the respondents preferred the transfer of multiple (2 or 3) embryos. Only three (5.6%) patients opted for single embryo transfer. Majority of the patients (31 or 60.8%) preferred multiple embryo transfer because of their desire for twins while twenty (39.2%) cited cost of IVF as their reason. Fifteen (29.4%) patients saw multiple pregnancies as a compensation for their long periods of infertility. CONCLUSION: With the desire for twins and high poverty level in Nigeria, a policy of single embryo transfer might be difficult to implement. Health economic studies would be required to determine if the accumulative cost of taking care of twins/triplets is less, equal or outweighs the cost of several single embryo transfers.
Subject(s)
Embryo Transfer , Fertilization in Vitro , Patient Preference/statistics & numerical data , Sperm Injections, Intracytoplasmic , Adult , Female , Humans , Middle Aged , Nigeria , Pregnancy , Prospective Studies , Treatment Outcome , Young AdultABSTRACT
INTRODUCTION: Alterations of serum lipid profiles have been reported widely among Human Immuno deficiency Virus (HIV) positive patients on Highly Active Anti Retroviral Therapy (HAART). However, there are few data on serum lipid profile among treatment naïve HIV positive patients in our environment. OBJECTIVES: To describe the pattern of lipid profile among treatment naïve HIV positive patients and changes following HAART initiation. METHODS: One hundred and thirty HIV positive patients seen in HIV center in an urban area in Nigeria and 44 matched individuals were recruited. Data were collected on socio demographic characters, baseline lipid profiles and CD4 count. Values of lipid parameters were retrieved after 12 months on HAART. RESULTS: The mean Low density lipoprotein(LDL) was 2.26+ 0.9 mmol/l among the test group compared with 0.96+0.39 mmol/L among the control, p value=0.000. The mean High density lipoprotein (HDL) was also significantly lower, 0.8+0.6 mmol/L reaching a dyslipidemic level, in the HIV positive group than the control, p value = 0.00. Tuberculosis/HIV co infected patients had a significantly elevated mean LDL, p=0.002. CONCLUSION: Abnormality of serum lipid is common among treatment naïve HIV patients seen in Nigeria. The NNRTI regimen is associated with elevation of HDL and some stabilization of TC and TG.
Subject(s)
Acquired Immunodeficiency Syndrome/drug therapy , Antiretroviral Therapy, Highly Active/adverse effects , Dyslipidemias/etiology , HIV Infections/drug therapy , Lipids/blood , Acquired Immunodeficiency Syndrome/blood , Acquired Immunodeficiency Syndrome/complications , Adult , Anti-HIV Agents/therapeutic use , Body Mass Index , CD4 Lymphocyte Count , Case-Control Studies , Cross-Sectional Studies , Dyslipidemias/complications , Female , HIV Infections/blood , HIV Infections/complications , Humans , Male , Middle Aged , Nigeria , Risk Factors , Socioeconomic Factors , Young AdultABSTRACT
Introduction: Alterations of serum lipid profiles have been reported widely among Human Immuno deficiency Virus (HIV) positive patients on Highly Active Anti Retroviral Therapy (HAART). However; there are few data on serum lipid profile among treatment na?ve HIV positive patients in our environment. Objectives: To describe the pattern of lipid profile among treatment na?ve HIV positive patients and changes following HAART initiation. Methods: One hundred and thirty HIV positive patients seen in HIV center in an urban area in Nigeria and 44 matched individuals were recruited. Data were collected on socio demographic characters; baseline lipid profiles and CD4 count. Values of lipid parameters were retrieved after 12 months on HAART. Results: The mean Low density lipoprotein(LDL) was 2.26+ 0.9 mmol/l among the test group compared with 0.96+0.39mmol/L among the control ;p value =0.000 .The mean High density lipoprotein (HDL) was also significantly lower;0.8+ 0.6mmol/L reaching a dyslipidemic level; in the HIV positive group than the control; p value = 0.00. Tuberculosis /HIV co infected patients had a significantly elevated mean LDL; p=0.002. Conclusion: Abnormality of serum lipid is common among treatment na?ve HIV patients seen in Nigeria. The NNRTI regimen is associated with elevation of HDL and some stabilization of TC and TG
Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , Lipids , NigeriaABSTRACT
Background: The Human Fertilization and Embryology Authority is considering limiting the number of embryos that can be transferred to single embryo per cycle as has been done in several European countries; with the aim of reducing the rate of multiple pregnancies and its attendant complications following in vitro fertilization (IVF) / Intracytoplasmic sperm injection (ICSI). Objective: To determine the number of embryos patients' attending a fertility clinic in Nigeria; would prefer transferred during IVF/ICSI. Materials and Methods: Fifty four consecutive female patients who underwent IVF/ICSI procedures between May 2006 and April 2007 at the Port Harcourt Fertility Centre; Rivers State were interviewed using structured questionnaires. They were informed of all the obstetric and perinatal complications of multiple pregnancies and the advantages and trend towards single embryo transfer and then asked to choose the number of embryos (one; two or three) they would prefer transferred assuming similar implantation rates. Each respondent was allowed to give reason(s) for their choice. Design: Prospective; descriptive study. Results: Fifty one (94.4) of the respondents preferred the transfer of multiple (2 or 3) embryos. Only three (5.6) patients opted for single embryo transfer. Majority of the patients (31 or 60.8) preferred multiple embryo transfer because of their desire for twins while twenty (39.2) cited cost of IVF as their reason. Fifteen (29.4) patients saw multiple pregnancies as a compensation for their long periods of infertility. Conclusion: With the desire for twins and high poverty level in Nigeria; a policy of single embryo transfer might be difficult to implement. Health economic studies would be required to determine if the accumulative cost of taking care of twins/triplets is less; equal or outweighs the cost of several single embryo transfers
Subject(s)
Embryo Transfer , Fertilization in Vitro , Patient PreferenceABSTRACT
The current status of replacement therapy for haemophilia and the role played by nurses in Japan were investigated at 16 facilities (17 specialties) each providing care to 20 or more haemophilia A or B patients without inhibitor. The questionnaire was mailed to the nurse or physician in charge of haemophilia at each facility in August 2006, asking the nurse to fill in the questionnaire. Responses were collected on 1318 patients (haemophilia A: 1078 patients; haemophilia B: 240 patients). About 70% of these patients were reported to be severe haemophilia A or B. Overall, 26% were receiving regular prophylaxis while 74% received on-demand therapy with or without temporary prophylaxis before special events. The percentage of patients receiving primary prophylaxis was only 2%. The percentage of adherence to prophylaxis decreased with age (lowest at age 19-29) but this percentage for each age group in Japan was higher than that in the western countries. Of the nurses working at the facilities surveyed, 88% considered prophylaxis as an optimal therapy for severe haemophilia patients, although the percentage of patients receiving prophylaxis for the entire population surveyed was lower than that in the western countries. The main factor precluding introduction of prophylaxis was 'difficulty in venous access' for infants and small children. On the other hand, 'unwillingness of family members' and 'poor adherence' were the main factors precluding introduction of this therapy for those aged over 6 years.
Subject(s)
Blood Coagulation Factor Inhibitors/therapeutic use , Hemophilia A/drug therapy , Hemophilia B/drug therapy , Patient Compliance/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Child , Child, Preschool , Health Care Surveys , Hemophilia A/psychology , Hemophilia B/psychology , Humans , Japan , Male , Middle Aged , Patient Compliance/psychology , Practice Patterns, Physicians' , Quality of Life , Surveys and Questionnaires , Treatment Outcome , Young AdultABSTRACT
The value of measuring the endometrial thickness and studying the endometrial receptivity in the context of assisted conception remains a contentious issue. A prospective analysis was carried out to determine the effect of endometrial thickness on IVF - embryo transfer/ICSI outcome in dedicated Assisted Reproductive Technology (ART) units in Abuja and Rivers State, Nigeria. Two hundred and fifty one patients who met the inclusion criteria were analysed. They were grouped on the basis of endometrial thickness into 3 groups; <7 mm, 7 - 14 mm and >14 mm. The main outcome measure was clinical pregnancy. There were significantly more pregnancies in the 7 - 14 mm endometrial thickness group compared to the <7 mm and >14 mm groups, p=0.004 and p<0.0001 respectively. The findings suggest that following IVF/ICSI, significantly more pregnancies occurred when the endometrial thickness was between 7 and 14 mm.
Subject(s)
Embryo Transfer , Endometrium/anatomy & histology , Sperm Injections, Intracytoplasmic , Adult , Chorionic Gonadotropin/administration & dosage , Endometrium/diagnostic imaging , Female , Glycoprotein Hormones, alpha Subunit/administration & dosage , Gonadotropin-Releasing Hormone/agonists , Humans , Infertility/therapy , Male , Nigeria , Pregnancy , Pregnancy Rate , Prospective Studies , Treatment Outcome , Ultrasonography , Young AdultABSTRACT
BACKGROUND: In functional gastrointestinal (GI) disorders including functional dyspepsia (FD) and irritable bowel syndrome (IBS), there might be no small extent of contributions of psychosomatic factors. As a therapy for IBS patients, the effectiveness of antidepressants has been reported. AIM: In this study, we evaluated the efficacy of H2-receptor antagonist (famotidine) and 5-HT4 receptor agonist (mosapride citrate). In addition, the effect of antidepressants was assessed as the second-step therapy. METHODS: Patients complaining upper GI symptoms were diagnosed as FD excluding organic diseases. Randomized patients received 20 mg/day of famotidine or 15 mg/day of mosapride citrate for 4 weeks and the efficacy was compared between the two groups based on a 10-point visual analogue scale. When symptoms were not relieved (score improvement 0-2 points), patients received amitriptyline (30 mg/day) or no medication for 4 weeks randomly. Patients who had depression in psychological test (SDS) were omitted. RESULTS: As the first-step therapy, both famotidine and mosapride showed beneficial effects regardless of FD subtypes, age and gender. The efficacy of these two drugs in relieving FD symptoms was not significantly different. In patients who failed in the first-step therapy, amitriptyline showed beneficial effects. CONCLUSIONS: These findings might be clinically important in view of the efficient relief of symptoms in FD patients.
Subject(s)
Amitriptyline/therapeutic use , Benzamides/therapeutic use , Dyspepsia/drug therapy , Famotidine/therapeutic use , Gastrointestinal Agents/therapeutic use , Morpholines/therapeutic use , Aged , Antidepressive Agents, Tricyclic/therapeutic use , Drug Therapy, Combination , Female , Humans , Male , Serotonin Receptor Agonists/therapeutic useABSTRACT
Various types of oculocutaneous albinism (OCA) are associated with reduced pigmentation in the skin, hair, and eyes that results from mutations in genes involved in melanin synthesis. Immortal mouse melanocyte lines (melan-a, melan-b, and melan-c) provide opportune models with which to investigate the etiology of two different types of OCA (types I and III), which arise from mutations in Tyr and Tyrp1, respectively. We compared intracellular processing, sorting, and degradation of tyrosinase and Tyrp1, and the effects on their catalytic function and melanin synthesis, in these wild-type and mutant melanocytes. A mutation in either Tyr or Tyrp1 increased the time of association of tyrosinase and Tyrp1 with calnexin and Bip, which in turn resulted in the retention of these mutant products in the ER. A mutation in either gene selectively enhanced the duration and efficiency of chaperone interactions (even with the wild-type protein in the mutant melanocytes) and markedly slowed their transport to melanosomes. These results show that OCA1 and OCA3 are (in some cases, at least) ER retention diseases wherein a mutation in one melanogenic protein affects the maturation and stability of the other in the melanogenic pathway.
Subject(s)
Albinism, Oculocutaneous/etiology , Endoplasmic Reticulum/physiology , Heat-Shock Proteins , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Monophenol Monooxygenase/genetics , Monophenol Monooxygenase/metabolism , Oxidoreductases , Albinism, Oculocutaneous/enzymology , Animals , Calcium-Binding Proteins/metabolism , Calnexin , Carrier Proteins/metabolism , Endoplasmic Reticulum Chaperone BiP , Hexosaminidases/chemistry , Intramolecular Oxidoreductases/metabolism , Macromolecular Substances , Melanins/analysis , Melanocytes/enzymology , Melanocytes/metabolism , Mice , Molecular Chaperones/metabolism , Mutation , Tumor Cells, CulturedABSTRACT
Melanogenesis cascade may be directly or indirectly linked to the dynamics of endosome-lysosome biogenesis. This study aims to identify how and to what extent the endosome-lysosome system is involved in melanosome biogenesis, by utilizing a novel melanogenesis marker, J1, which we identified in the process of developing monoclonal antibodies (MoAbs) against human melanosomes. The antigenic epitope of MoAb J1 was expressed by all of the melanotic and nonmelanotic cells examined. It was expressed primarily by granular structures located in regions proximal to the Golgi complex. Most of MoAb J1 positive granules were co-stained with melanogenic markers, tyrosinase or tyrosinase-related protein (TRP-1). The epitope of MoAb J1 was also coexpressed by most, but not all, of LGP85 (a lysosomal marker) positive granules in both melanoma and non-melanoma cells, indicating that MoAb J1 recognizes a subset of lysosomal vesicles. MoAb J1 did not, however, react with vesicles with late/early (syntaxin 8/ EEA1) endosomal markers. Further examination using fluorophore-labeled pepstatin, a marker of lysosomal luminal content, confirmed that MoAb J1 specifically recognizes the luminal surface of lysosomes. These results indicate that MoAb J1 possesses an antigen epitope that is expressed in the luminal component of prelysosomal granules which are involved in the biogenesis cascade common to both melanosomes and lysosomes. We suggest that tyrosinase family protein, tyrosinase and TRP-1 are transported to melanosomes from TGN via these prelysosomal granules after being transiently transported to late endosomes.
Subject(s)
Antibodies, Monoclonal/immunology , Epitopes/immunology , Lysosomes/immunology , Melanosomes/immunology , Animals , Mice , Rabbits , Tumor Cells, CulturedABSTRACT
Excessive nitric oxide (NO) production in cytokine-activated beta cells has been implicated in beta cell disruption in type 1 diabetes. beta cells are very vulnerable to NO-induced apoptosis. However, the mechanism underlying this phenomenon is unclear. Low concentrations of NO that lead to apoptosis apparently do not cause severe DNA damage in mouse MIN6 beta cells. CHOP, a C/EBP homologous protein that is induced by endoplasmic reticulum (ER) stress and plays a role in growth arrest and cell death, was induced by a NO donor, S-nitroso-N-acetyl-D,L-penicillamine (SNAP). SNAP increased cytosolic Ca(2+), and only agents depleting ER Ca(2+) induced CHOP expression and led to apoptosis, suggesting that NO depletes ER Ca(2+). Overexpression of calreticulin increased the Ca(2+) content of ER and afforded protection to cells against NO-mediated apoptosis. Furthermore, pancreatic islets from CHOP knockout mice showed resistance to NO. We conclude that NO depletes ER Ca(2+), causes ER stress, and leads to apoptosis. Thus, ER Ca(2+) stores are a new target of NO, and the ER stress pathway is a major mechanism of NO-mediated beta cell apoptosis.
Subject(s)
Apoptosis , Endoplasmic Reticulum/metabolism , Islets of Langerhans/cytology , Nitric Oxide/metabolism , Animals , CCAAT-Enhancer-Binding Proteins/genetics , Calcium/metabolism , Calcium-Binding Proteins/genetics , Calreticulin , Cyclic GMP/metabolism , DNA Damage , Drug Resistance , Endoplasmic Reticulum/drug effects , Homeostasis , Interferon-gamma/pharmacology , Interleukin-1/pharmacology , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Mice , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Ribonucleoproteins/genetics , Transcription Factor CHOP , Transcription Factors/genetics , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
Toll-like receptor 2 (TLR2) and CD14 function as pattern recognition receptors for bacterial peptidoglycan (PGN). TLRs and CD14 possess repeats of the leucine-rich motif. To address the role of the extracellular domain of TLR2 in PGN signaling, we constructed CD14/TLR2 chimeras, in which residues 1-356 or 1-323 of CD14 were substituted for the extracellular domain of TLR2, and five deletion mutants of TLR2, in which the progressively longer regions of extracellular TLR2 regions were deleted. PGN induced NF-kappaB activation in HEK293 cells expressing TLR2 but not in cells expressing CD14/TLR2 chimeras. The cells transfected with a deletion mutant TLR2(DeltaCys30-Ile64) as well as TLR2(DeltaCys30-Asp160) and TLR2(DeltaCys30-Asp305) failed to respond to PGN, indicating the importance of the TLR2 region Cys(30)-Ile(64). Although TLR2(DeltaCys30-Ser39) conferred cell responsiveness to PGN, the cells expressing TLR2(DeltaSer40-Ile64) failed to induce NF-kappaB activation. In addition, NF-kappaB activity elicited by PGN was significantly attenuated in the presence of synthetic peptide corresponding to the TLR2 region Ser(40)-Ile(64). From these results, we conclude that; 1) CD14 cannot functionally replace the extracellular domain of TLR2 in PGN signaling; 2) the TLR2 region Cys(30)-Ser(39) is not required for PGN recognition; 3) the TLR2 region containing Ser(40)-Ile(64) is critical for PGN recognition.
Subject(s)
Cysteine/metabolism , Drosophila Proteins , Isoleucine/metabolism , Membrane Glycoproteins/metabolism , Peptidoglycan/metabolism , Receptors, Cell Surface/metabolism , Serine/metabolism , Staphylococcus aureus/metabolism , Amino Acid Sequence , Base Sequence , Cell Line , DNA Primers , Humans , Lipopolysaccharide Receptors/genetics , Membrane Glycoproteins/chemistry , Membrane Glycoproteins/genetics , Molecular Sequence Data , Mutagenesis , NF-kappa B/metabolism , Receptors, Cell Surface/chemistry , Receptors, Cell Surface/genetics , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Toll-Like Receptor 2 , Toll-Like ReceptorsABSTRACT
The quality control mechanism in the endoplasmic reticulum (ER) discriminates correctly folded proteins from misfolded polypeptides and determines their fate. Terminally misfolded proteins are retrotranslocated from the ER and degraded by cytoplasmic proteasomes, a mechanism known as ER-associated degradation (ERAD). We report the cDNA cloning of Edem, a mouse gene encoding a putative type II ER transmembrane protein. Expression of Edem mRNA was induced by various types of ER stress. Although the luminal region of ER degradation enhancing alpha-mannosidase-like protein (EDEM) is similar to class I alpha1,2-mannosidases involved in N-glycan processing, EDEM did not have enzymatic activity. Overexpression of EDEM in human embryonic kidney 293 cells accelerated the degradation of misfolded alpha1-antitrypsin, and EDEM bound to this misfolded glycoprotein. The results suggest that EDEM is directly involved in ERAD, and targets misfolded glycoproteins for degradation in an N-glycan dependent manner.
Subject(s)
Endoplasmic Reticulum/metabolism , Glycoproteins/metabolism , Membrane Proteins/metabolism , Protein Folding , alpha 1-Antitrypsin/metabolism , Alkaloids/pharmacology , Amino Acid Sequence , Animals , Cell Line , Cloning, Molecular , Endoplasmic Reticulum/chemistry , Enzyme Inhibitors/pharmacology , Gene Expression Regulation/genetics , Humans , Mannosidases/antagonists & inhibitors , Mannosidases/genetics , Mannosidases/metabolism , Membrane Proteins/chemistry , Membrane Proteins/genetics , Mice , Molecular Sequence Data , RNA/genetics , RNA/metabolism , Rabbits , Sequence Alignment , Serine Proteinase Inhibitors/metabolism , Transfection , alpha 1-Antitrypsin/chemistry , alpha-MannosidaseABSTRACT
Oculocutaneous albinism type 1 (OCA1) is an autosomal recessive disease resulting from mutations of the tyrosinase gene (TYR). To elucidate the molecular basis of OCA1 phenotypes, we analysed the early processing and maturation of several different types of mutant tyrosinase with various degrees of structural abnormalities (i.e. two large deletion mutants, two missense mutants that completely destroy catalytic function and three missense mutants that have a temperature-sensitive phenotype). When expressed in COS7 cells, all mutant tyrosinases were sensitive to endoglycosidase H digestion, and immunostaining showed their localization in the endoplasmic reticulum (ER) and their failure to be sorted further to their target organelles. Pulse-chase experiments showed that all mutant tyrosinases were retained by calnexin in the ER and that they were degraded at similarly rapid rates, which coincided with their dissociation from calnexin. Temperature-sensitive mutant enzymes were sorted more efficiently at 31 degrees C than at 37 degrees C, and their degradation was accelerated at 37 degrees C compared with 31 degrees C. Thus in contrast to the current concept that mutant tyrosinases are transported to melanosomes but are functionally inactive there, our results suggest that mutant tyrosinases may not be transported to melanosomes in the first place. We conclude that a significant component of mutant tyrosinase malfunction in OCA1 results from their retention and degradation in the ER compartment. This quality-control process is highly sensitive to minimal changes in protein folding, and so even relatively minor mutations in peripheral sequences of the enzyme not involved with catalytic activity may result in a significant reduction of functional enzyme in melanosomes.
Subject(s)
Albinism, Oculocutaneous/enzymology , Monophenol Monooxygenase/metabolism , Pigmentation/genetics , Albinism, Oculocutaneous/genetics , Animals , COS Cells , Calcium-Binding Proteins/metabolism , Calnexin , Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Endoplasmic Reticulum/metabolism , Humans , Hydrolysis , Immunohistochemistry , Monophenol Monooxygenase/genetics , Multienzyme Complexes/metabolism , Proteasome Endopeptidase Complex , Protein Transport , Subcellular Fractions/enzymology , TemperatureABSTRACT
Granisetron (GRN) is widely used for patients with various cancers who suffer from chemotherapy-induced vomiting and nausea. The, pharmacokinetics of GRN has not been fully evaluated in such patients, however, and its dosage regimen is still controversial. In this study, we determined GRN levels in serum and urine from lung cancer patients and children suffering from cancer after intravenous infusion. In lung cancer patients, the interindividual variations in t(1/2beta), area under the concentration-time curve (AUC), and Vd(beta) were relatively smaller than expected from previous reports on healthy subjects, while t(1/2beta) was prolonged more than 5-fold in healthy subjects. Urinary excretion of unchanged GRN in lung cancer patients was ca. 15% of dose, consistent with previous reports, and one individual demonstrated an even higher urinary excretion (ca. 45%). The pharmacokinetic parameters of GRN in child cancer patients varied markedly among individuals, and some child patients had smaller t(1/2beta) than adult patients. In these cases, GRN should be administered at shorter intervals. These results suggested that a pharmacokinetic study of GRN was necessary for planning a dosage regimen and managing chemotherapy-induced vomiting and nausea.