The molecular mechanisms of probiotic strains in improving ageing bone and muscle of d-galactose-induced ageing rats.

AIM: The aim of this study was to evaluate the molecular mechanisms of Lactobacillus strains in improving ageing of the musculoskeletal system. METHODS AND RESULTS: The anti-ageing mechanism of three probiotics strains Lactobacillus fermentum DR9, Lactobacillus paracasei OFS 0291 and L. helveticus OFS 1515 were evaluated on gastrocnemius muscle and tibia of d-galactose-induced ageing rats. Upon senescence induction, aged rats demonstrated reduced antioxidative genes CAT and SOD expression in both bone and muscle compared to the young rats (P < 0·05). Strain L. fermentum DR9 demonstrated improved expression of SOD in bone and muscle compared to the aged rats (P < 0·05). In the evaluation of myogenesis-related genes, L. paracasei OFS 0291 and L. fermentum DR9 increased the mRNA expression of IGF-1; L. helveticus OFS 1515 and L. fermentum DR9 reduced the expression of MyoD, in contrast to the aged controls (P < 0·05). Protective effects of L. fermentum DR9 on ageing muscle were believed to be contributed by increased AMPK-α2 expression. Among the osteoclastogenesis genes studied, TNF-α expression was highly elevated in tibia of aged rats, while all three probiotics strains ameliorated the expression. Lactobacillus fermentum DR9 also reduced the expression of IL-6 and TRAP in tibia when compared to the aged rats (P < 0·05). All probiotics treatment resulted in declined proinflammatory cytokines IL-1ß in muscle and bone. CONCLUSIONS: Lactobacillus fermentum DR9 appeared to be the strongest strain in modulation of musculoskeletal health during ageing. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrated the protective effects of the bacteria on muscle and bone through antioxidative and anti-inflammatory actions. Therefore, L. fermentum DR9 may serve as a promising targeted anti-ageing therapy.

Lactobacillus plantarum DR7 alleviates stress and anxiety in adults: a randomised, double-blind, placebo-controlled study.

Probiotics have been reported to exert beneficial effects along the gut-brain axis. This randomised, double-blind and placebo-controlled human study aimed to evaluate such properties of Lactobacillus plantarum DR7 and its accompanying mechanisms in stressed adults. One hundred and eleven (n=111; DR7 n=56, placebo n=55) stressed adults were recruited based on moderate stress levels using the PSS-10 questionnaire. The consumption of DR7 (1×109 cfu/day) for 12 weeks reduced symptoms of stress (P=0.024), anxiety (P=0.001), and total psychological scores (P=0.022) as early as 8 weeks among stressed adults compared to the placebo group as assessed by the DASS-42 questionnaire. Plasma cortisol level was reduced among DR7 subjects as compared to the placebo, accompanied by reduced plasma pro-inflammatory cytokines, such as interferon-γ and transforming growth factor-α and increased plasma anti-inflammatory cytokines, such as interleukin 10 (P<0.05). DR7 better improved cognitive and memory functions in normal adults (>30 years old), such as basic attention, emotional cognition, and associate learning (P<0.05), as compared to the placebo and young adults (<30 years old). The administration of DR7 enhanced the serotonin pathway, as observed by lowered expressions of plasma dopamine ß-hydroxylase (DBH), tyrosine hydroxylase (TH), indoleamine 2,3-dioxygenase and tryptophan 2,3-dioxygenase accompanied by increased expressions of tryptophan hydroxylase-2 and 5-hydroxytryptamine receptor-6, while stabilising the dopamine pathway as observed via stabilised expressions of TH and DBH over 12 weeks as compared to the placebo (P<0.05). Our results indicated that DR7 fulfil the requirement of a probiotic strain as per recommendation of FAO/WHO and could be applicable as a natural strategy to improve psychological functions, cognitive health and memory in stressed adults.

Bifidobacterium longum BB536 alleviated upper respiratory illnesses and modulated gut microbiota profiles in Malaysian pre-school children.

This 10-months randomised, double-blind, parallel and placebo-controlled study evaluated the effects of Bifidobacterium longum BB536 on diarrhoea and/or upper respiratory illnesses in 520 healthy Malaysian pre-school children aged 2-6 years old. The subjects randomly received a one-gram sachet containing either BB536 (5×109 cfu) or placebo daily. Data analysis was performed on 219 subjects who fully complied over 10-months (placebo n=110, BB536 n=109). While BB536 did not exert significant effects against diarrhoea in children, Poisson regression with generalised estimating equations model indicated significant intergroup difference in the mean number of times of respiratory illnesses over 10 months. The duration of sore throat was reduced by 46% (P=0.018), with marginal reduction for duration of fever (reduced by 27%, P=0.084), runny nose (reduced by 15%, P=0.087) and cough (reduced by 16%, P=0.087) as compared to the placebo. Principal coordinate analysis at genus level of the gut microbiota revealed significant differences between 0 and 10 months in the BB536 group (P<0.01) but not in placebo group (P>0.05). The abundance of the genus Faecalibacterium which is associated with anti-inflammatory and immuno-modulatory properties was significantly higher in the BB536 group (P<0.05) compared to the placebo group. Altogether, our present study illustrated the potential protective effects of BB536 against upper respiratory illnesses in pre-school Malaysian children, with gut microbiota modulating properties.

The efficacy of laparoscopic intracorporeal linear suture technique as a strategy for reducing recurrences in pediatric inguinal hernia.

PURPOSE: Pediatric laparoscopic herniorrhaphy has rare complications, but recurrence might occur. The purpose of this manuscript is to evaluate the efficacy of linear suture technique of laparoscopic pediatric herniorrhaphy in reducing recurrences. METHODS: Laparoscopic surgery was performed on 2223 pediatric patients (under 10 years old) from September 2012 to December 2014 in Damsoyu Hospital, Seoul, Republic of Korea. The causes of recurrence were investigated case by case. The patients were categorized into two groups according to the suture method used in closing the hernia orifice: Group 1 (purse-string suture, 1009 patients) and Group 2 (linear suture, 1214 patients). RESULTS: There were 1413 (63.6%) male and 810 (36.4%) female patients. Mean age was 30.5 ± 29.2 months. A significantly higher proportion of male patients, contralateral patent processus vaginalis, and less proportion of recurrence were observed in Group 2. There were ten cases of recurrence in Group 1 because the internal ring suture could not endure the tension. One recurrence occurred in Group 2. The suture technique and age were found to be a significant risk factor for recurrence. Linear suture technique had a lower recurrence rate (odds ratio = 0.07, with 95% confidence interval 0.01-0.53, and p = 0.004). CONCLUSIONS: Purse-string suture technique causes significantly higher occurrence of hernia recurrences than linear suture technique. Linear suture technique can reduce recurrence by increasing the endurance to tension around the internal ring by distributing pressure to a wider area along the linear suture line. Linear suture technique can effectively reduce recurrence in pediatric inguinal herniorrhaphy.

Aerothermoelastic-Acoustics Simulation of Flight Vehicles.

This paper describes a novel computational-fluid-dynamics-based numerical solution procedure for effective simulation of aerothermoacoustics problems with application to aerospace vehicles. A finite element idealization is employed for both fluid and structure domains, which fully accounts for thermal effects. The accuracies of both the fluid and structure capabilities are verified with flight- and ground-test data. A time integration of the structural equations of motion, with the governing flow equations, is conducted for the computation of the unsteady aerodynamic forces, which uses a transpiration boundary condition at the surface nodal points in lieu of the updating of the fluid mesh. Two example problems are presented herein to that effect. The first one relates to a cantilever wing with a NACA 0012 airfoil. The solution results demonstrate the effect of temperature loading that causes a significant increase in acoustic response. A second example, the hypersonic X-43 vehicle, is also analyzed; and relevant results are presented. The common finite element-based aerothermoelastic-acoustics simulation process, its applicability to the efficient and routine solution of complex practical problems, the employment of the effective transpiration boundary condition in the computational fluid dynamics solution, and the development and public domain distribution of an associated code are unique features of this paper.

Prenylated xanthones from mangosteen as promising cholinesterase inhibitors and their molecular docking studies.

Garcinia mangostana is a well-known tropical plant found mostly in South East Asia. The present study investigated acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of G. mangostana extract and its chemical constituents using Ellman's colorimetric method. Cholinesterase inhibitory-guided approach led to identification of six bioactive prenylated xanthones showing moderate to potent cholinesterases inhibition with IC50 values of lower than 20.5 µM. The most potent inhibitor of AChE was garcinone C while γ-mangostin was the most potent inhibitor of BChE with IC50 values of 1.24 and 1.78 µM, respectively. Among the xanthones, mangostanol, 3-isomangostin, garcinone C and α-mangostin are AChE selective inhibitors, 8-deoxygartanin is a BChE selective inhibitor while γ-mangostin is a dual inhibitor. Preliminary structure-activity relationship suggests the importance of the C-8 prenyl and C-7 hydroxy groups for good AChE and BChE inhibitory activities. The enzyme kinetic studies indicate that both α-mangostin and garcinone C are mixed-mode inhibitors, while γ-mangostin is a non-competitive inhibitor of AChE. In contrast, both γ-mangostin and garcinone C are uncompetitive inhibitors, while α-mangostin is a mixed-mode inhibitor of BChE. Molecular docking studies revealed that α-mangostin, γ-mangostin and garcinone C interacts differently with the five important regions of AChE and BChE. The nature of protein-ligand interactions is mainly hydrophobic and hydrogen bonding. These bioactive prenylated xanthones are worthy for further investigations.

Incidental renal cell carcinoma originating from a native kidney after en-bloc resection for adrenal carcinoma in a kidney transplant recipient.

BACKGROUND: Renal transplantation is the best treatment for patients with end-stage renal disease. Although there is significantly increased risk of malignancy after renal transplantation, carcinoma of the native kidney is very rare, and moreover, the risk of endocrinologic malignancy after renal transplantation is lower than in the general population and adrenal cortical carcinoma extremely rare. We report a case of incidental renal cell carcinoma originating from a native kidney after en-bloc resection for adrenal carcinoma in a kidney transplant recipient. CASE REPORT: A 57 year-old male patient had undergone living-donor kidney transplantation for chronic renal failure from hypertension 15 years earlier and had a right adrenal tumor diagnosed on surveillance abdomen-pelvis computerized tomography. Based on 24-hour catecholamine laboratory findings, nonfunctioning tumor was suspected. The planned en-bloc resection of right adrenal gland and right native kidney combining the perirenal tissue and Gerota fascia was performed, because the tumor was suspicious for malignancy and could possibly invade the perirenal tissue or right kidney. On the final pathology, combined adrenal cortical carcinoma and incidental renal cell carcinoma was confirmed. Renal cell carcinoma was papillary, type I, and stage T1N0M0. Adrenal cortical carcinoma was 7.6 × 6.5 cm in size, had marked nuclear atypia, and was grade IV/IV. Mitotic counts were >10 per high-power field, but it had no capsular invasion or vascular invasion, and free resection margin was confirmed. In the preoperative period, he had taken immunosuppressants FK506 and mycophenolate sodium, but after combined carcinomas were confirmed, the regimen of combination of immunosuppressants was changed to sirolimus with low-dose FK506 and half-dose mycophenolate sodium.

Mn(2+) and Mg(2+) synergistically enhanced lactic acid production by Lactobacillus rhamnosus FTDC 8313 via affecting different stages of the hexose monophosphate pathway.

AIMS: The study aimed to evaluate the effects of Mn(2+) and Mg(2+) on lactic acid production using response surface methodology and to further study their effects on interactions between the enzymes and substrates along the hexose monophosphate pathway using a molecular modelling approach. METHODS AND RESULTS: A rotatable central composite design matrix for lactic acid production was generated with two independent factors namely, manganese sulfate and magnesium sulfate. The second-order regression model indicated that the quadratic model was significant (P < 0·05), suggesting that the model accurately represented the data in the experimental region. Three-dimensional response surface showed that lactic acid production was high along the region where the ratio of MnSO4 to MgSO4 was almost 1 : 1, justifying the need for both Mg(2+) and Mn(2+) to be present simultaneously in stimulating the production of lactic acid. Molecular docking simulation was performed on a total of 13 essential enzymes involved in the hexose monophosphate pathway for the production of lactic acid with four different conditions namely in the presence of Mg(2+) , Mn(2+) , both Mg(2+) and Mn(2+) and in the absence of metal ions. Results showed that the presence of both Mg(2+) and Mn(2+) within the binding site improved the binding affinity for substrates in five enzymes namely, glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate hydratase and pyruvate kinase. CONCLUSIONS: Using response surface methodology and molecular modelling approach, we illustrated that Mg(2+) and Mn(2+) synergistically enhanced lactic acid production by Lactobacillus rhamnosus FTDC 8313 via affecting different stages of the hexose monophosphate pathway. SIGNIFICANCE AND IMPACTS OF THE STUDY: Mg(2+) and Mn(2+) synergistically improved lactic acid production of Lact. rhamnosus via improved binding affinity of the enzyme-substrate along the hexose monophosphate pathway, instead of purely affecting growth as previously understood.

Does procurement technique affect posttransplant graft function in deceased donor liver transplantation?

INTRODUCTION: Various techniques have been described deceased donor liver transplantation (DDLT) procurement. One is a technique whereby almost total dissection is done in the porta hepatis and perihepatic detachment is carried out before cross-clamping the donor aorta. In another approach, after the donor aorta is cross-clamped, rapid and minimal en bloc dissection is performed with minimal manipulation. We evaluated early posttransplant graft function among liver procurement techniques. METHOD: Between January 2008 and August 2012, we performed 45 consecutive adult DDLTs. One patient was excluded from this analysis due to early death from sepsis after transplantation. The 44 included patients were divided into two cohorts according to the procurement technique: A warm dissection (n = 23; 52%) and a cold dissection group (n = 21; 48%). We compared early posttransplant graft function using the aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T-bil), and prothrombin time (PT) values of the two groups from the first to seventh postoperative day. RESULT: The AST values in the warm group were significantly greater than those in the cold group on postoperative days 3 and 5. In addition, the ALT values in the warm group were greater than those in the cold group on postoperative days 4, 5, and 6. Moreover, the T-bil values in the warm group were greater than those in the cold group on postoperative days 2, 3, 4, 5, 6, and 7. However, there were no differences in PT values. CONCLUSION: During liver procurement for DDLT, rapid en bloc procurement with minimal manipulation after clamping the donor aorta achieved better early graft function posttransplantation.

Electric field-induced coherent control in GaAs: polarization dependence and electrical measurement [Invited].

A static electric field enables coherent control of the photoexcited carrier density in a semiconductor through the interference of one- and two-photon absorption. An experiment using optical detection is described. The polarization dependence of the signal is consistent with a calculation using a 14-band k · p model for GaAs. We also describe an electrical measurement. A strong enhancement of the phase-dependent photocurrent through a metal-semiconductor-metal structure is observed when a bias of a few volts is applied. The dependence of the signal on bias and laser spot position is studied. The field-induced enhancement of the signal could increase the sensitivity of semiconductor-based carrier-envelope phase detectors, useful in stabilizing mode-locked lasers for use in frequency combs.

Invasive pulmonary aspergillosis after living donor liver transplantation should be eradicated or not? A case report.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) is a rare complication with a high mortality rate after organ transplantation. Early antifungal therapy improves survival. In some cases, surgical resection is necessary for a complete remission. We have reported herein a case of sustained (but stationary) IPA cured by the modulation of immunosuppression with discontinuation of antifungal therapy. CASE: A 34-year-old man underwent liver transplantation experiencing are early bile leak and an acute rejection episode. Steroid pulse therapy was accompanied by intensified immunosuppression. After a week he developed intermittent hemoptysis, which was treated with antibiotics due to a diagnosis of pneumonia by chest X ray. Meanwhile the bile leak progressed to a huge biloma at reoperation 3 weeks after the initial operation he was converted from a choledochocholedochostomy to a hepaticojejunostomy. After 1 week, follow-up chest X ray showed the lesion had progressed to form an abscess. Subsequent chest computed tomography (CT) detected a pulmonary mass with internal necrosis and CT-guided lung biopsy revealed Aspergillus fumigatus on isolation. Antifungal therapy with voriconazole and/or amphotericin B for 3 months stopped disease progression but the lesion was sustained. We stopped antifungal therapy due to side effects and reduced the intensity of immunosuppression. Follow-up chest CT 5 months later showed improvement with a persistent cavitary lesion containing a fungal ball. However, after 9 months, there was no focal lesion in either lung. This unusual case of IPA was cured by reducing immunosuppression without antifungal therapy. CONCLUSION: IPA should be eradicated with prompt antifugal therapy, but stationary IPA can be observed cautiously while reducing immunosuppression.

Surgical outcomes and prognostic factors for ampulla of Vater cancer.

BACKGROUND AND AIMS: The prognosis for patients with ampulla of Vater cancer is better than other periampullary cancers. The aim of the present study is to determine the clinicopathologic factors predictive of survival and recurrence in patients with ampulla of Vater cancer. MATERIAL AND METHODS: From 1991 to 2008, we identified and reviewed 78 patients with ampulla of Vater cancer retrospectively. Clinicopathologic factors possibly influencing survival and recurrence were statistically analyzed. RESULTS: Pancreaticoduodenectomy was performed in 68 patients and 2 patients underwent transduodenal ampullectomy. Hospital mortality was 2.6%. The 5-year survival rates following resection were 59.9%. Univariate analysis for overall survival revealed that total bilirubin greater than 5 mg/dl, ulcerative tumors, differentiation, and pancreatic invasion were significant prognostic factors. Recurrence occurred in 31 patients. Univariate analysis for disease-free survival revealed that total bilirubin greater than 5mg/dl, preoperative biliary drainage, tumor differentiation, and stage were statistically significant. Multivariate analysis revealed that tumor differentiation was an independent prognostic factor for recurrence. The presence of lymph node metastasis did not affect overall survival significantly in this study. However, two or more metastatic lymph nodes significantly affect disease-free survival. CONCLUSIONS: Pancreaticoduodenectomy is a safe surgical procedure with acceptable long-term survival for ampulla of Vater cancer. Pancreaticoduodenectomy with lymph node dissection might control lymph node spread and enhance survival outcome.

Optical coherent control induced by an electric field in a semiconductor: a new manifestation of the Franz-Keldysh effect.

In (100)-oriented GaAs illuminated at normal incidence by a laser and its second harmonic, interference between one- and two-photon absorption results in ballistic current injection, but not modulation of the overall carrier injection rate. Results from a pump-probe experiment on a transversely biased sample show that a constant electric field enables coherent control of the carrier injection rate. We ascribe this to the nonlinear optical Franz-Keldysh effect and calculate it for a two-band parabolic model. The mechanism is relevant to centrosymmetric semiconductors as well.

Contactless photoconductive terahertz generation.

We describe a pulsed terahertz (THz) emitter that uses a rapidly oscillating, high-voltage bias across electrodes insulated from a photoconductor. Because no carriers are injected from the electrodes, trap-enhanced electric fields do not form. The resulting uniform field allows excitation with a large laser spot, lowering the carrier density for a given pulse energy and increasing the efficiency of THz generation. Compared to a dc bias, less susceptibility to damage is observed.

The efficacy of portal vein embolization prior to right extended hemihepatectomy for hilar cholangiocellular carcinoma: a retrospective cohort study.

BACKGROUND/PURPOSE: Preoperative portal vein embolization was introduced to minimize complications after extended hepatectomy. This retrospective cohort study was conducted to compare outcomes with and without portal vein embolization before hepatectomy for hilar cholangiocellular carcinoma. METHODS: This study was conducted with 35 patients who underwent right extended hemihepatectomy for hilar cholangiocellular carcinoma from 2001 to 2008. Preoperative portal vein embolization was performed in 14 patients (embolization group) and not performed in 21 patients (non-embolization group). RESULTS: The groups did not differ in terms of sex, age, operative time, transfusion, postoperative serum bilirubin level, prothrombin time, and length of intensive care unit (ICU) stay. Although blood loss was higher in the embolization group than in the non-embolization group (P = .009), no major complications were observed between embolization and resection. At presentation, future liver remnant was smaller in the embolization group (19.8%, range 16-35%) than in non-embolization group (28.3%, 15-47%; P = .001). After embolization, the volume of the future liver remnant increased significantly to 27.2% (range, 23-42%; P = .001). Future liver remnants just before operation were similar in both groups (P > .99). There was no significant difference in terms of the rate of morbidity and in-hospital mortality. No statistically significant differences were observed in disease-free survival (P = .52) and overall survival (P = .30). CONCLUSIONS: Portal vein embolizations do not increase the rate of morbidity, in-hospital mortality, local recurrence and system metastasis. Therefore it can be considered safe and effective for patients with small future liver remnants. Embolization can lessen postoperative liver failure and widen the indication of the surgical resection, especially in patients with marginal future liver remnants.

Sigmoid colon fistula following totally extraperitoneal hernioplasty: an improper treatment for mesh infection or iatrogenic injury?

BACKGROUND: There are only a few reports of severe mesh-related complications, and major bowel complications after totally extraperitoneal (TEP) hernioplasty are also rare. CASE REPORT: A 75-year-old male patient, who had undergone TEP hernioplasty for a left inguinal hernia 2 months previously, presented with a left inguinal swelling that was found to be due to sigmoid colon-related mesh complications following TEP hernioplasty. CONCLUSIONS: Infection is an accepted complication of hernia operation; however, it may be more serious following laparoscopic techniques. Successful TEP hernioplasty requires adequate dissection and complete exposure and coverage of all potential sites that cause inguinal hernia. If infection and suppuration are resistant to conservative methods or occur in the early postoperative period, aggressive imaging study and treatment provides definitive treatment and reduces the burden of complications.

Terahertz near-field enhancement in narrow rectangular apertures on metal film.

We report huge field accumulations in rectangular aperture arrays on thin metal film by using shape resonance in THz frequency region. A huge far-field transmission enhancement is observed in samples of various widths ranging from 10 mum to 1.8 mum which correspond to only an order of lambda/100. Theoretical calculations based on vector diffraction theory indicates 230 times near-field enhancement in case of the 1.8 mum wide rectangular aperture. Transmission measurement through the single rectangular aperture shows that the shape resonance, not the periodicity, is mainly responsible for the transmission enhancement and the corresponding field enhancement.

Central bisectionectomy for centrally located hepatocellular carcinoma.

BACKGROUND: Central bisectionectomy, which involves the removal of the central hepatic segments (IVA, IVB, V, VIII) for hepatocellular carcinoma (HCC), is performed to reduce the volume of resected liver and to overcome the problem of insufficient future residual volume. METHODS: Twenty-seven patients with HCC underwent central bisectionectomy from January 1998 to April 2007 in one hospital. The surgical techniques, clinicopathological characteristics and outcomes were reviewed. RESULTS: The median operating time was 330 min. Twelve patients developed postoperative complications and two died. The most common complication, occurring in five patients, was bile duct injury leading to biloma or bile leakage. Median follow-up was 19.1 (range 1.4-102.2) months and eight patients developed a recurrence. Twenty-four patients were alive at the time of writing. CONCLUSION: Although biliary complications occur somewhat frequently, central bisectionectomy in centrally located HCC can be performed safely to preserve liver volume.

Effects of ultraviolet intensity and wavelength on the photolysis of triclosan.

The effects of ultraviolet (UV) intensity and wavelength on triclosan (TCS) photodegradation kinetic, efficiency, mechanisms and pathway were studied. The TCS photodegradation followed the pseudo-first order kinetic model at all UV intensities examined at the wavelengths of 254 and 365 nm and the photodegradation rate increased with increasing UV intensity. TCS photodegradation efficiencies of 90 to 98% and 79 to 90% were obtained at the wavelengths of 254 and 365 nm, respectively. TCS was degraded mainly by photon induced hydroxyl radicals while the direct photon reaction with TCS played a subordinate role. Chlorophenol, dichlorophenol and phenol were the intermediates detected in all experiments conducted. Dibenzodichloro-p-dioxin and dibenzo-p-dioxin were observed as the intermediates only at lower UV intensities investigated at the wavelength of 365 nm. Based on these intermediates, a complete TCS photolysis pathway was proposed for the first time.

Lead biosorption by waste biomass of Corynebacterium glutamicum generated from lysine fermentation process.

Biomass waste, mainly Corynebacterium glutamicum, is generated from large-scale lysine fermentation process. In this study, protonated C. glutamicum biomass was evaluated as a biosorbent for the removal of lead from synthetic wastewater. As Pb2+ were bound to the biomass, the solution pH deceased, indicating that protons in the biomass were exchanged with lead ions. The Corynebacterium biomass bound Pb2+ at up to 2.74 mmol g(-1) at pH 5, where lead does not precipitate. Compared with other biosorbents and conventional sorbents, such as natural zeolite, activated carbon and synthetic ion exchange resin, the protonated C. glutamicum biomass was considered to be a useful biomaterial for lead biosorption.