Biodegradable gelatin/beta-tricalcium phosphate sponges incorporating recombinant human fibroblast growth factor-2 for treatment of recession-type defects: A split-mouth study in dogs.

BACKGROUND AND OBJECTIVE: Tissue engineering by using recombinant human (rh) growth factor technology may offer a promising therapeutic approach for treatment of gingival recession. Fibroblast growth factor-2 (FGF-2) has shown the ability to promote periodontal regeneration. Gelatin/beta-tricalcium phosphate (gelatin/ß-TCP) sponges have been developed to control the release of growth factors. The present study evaluated the periodontal regenerative efficacy of rhFGF-2 by comparing gelatin/ß-TCP sponges incorporated with rhFGF-2 to the scaffolds alone in artificially created recession-type defects in dogs. MATERIAL AND METHODS: Critically sized buccal gingival recession defects were surgically created on maxillary canine teeth of five dogs. In each animal, defects were randomized to receive either a gelatin/ß-TCP sponge soaked with rhFGF-2 (gelatin/ß-TCP/rhFGF-2) or phosphate-buffered saline (gelatin/ß-TCP). Eight weeks after surgery, biopsy specimens were obtained and subjected to microcomputed tomography and histological analyses. RESULTS: Complete root coverage was achieved in both groups. Microcomputed tomography revealed significantly greater new bone volume in the gelatin/ß-TCP/rhFGF-2 group. Histologically, both groups achieved periodontal regeneration; however, gelatin/ß-TCP/rhFGF-2 sites exhibited more tissue regeneration, characterized by significantly larger amounts of new cementum and new bone. Gelatin/ß-TCP sites featured increased long junctional epithelium and connective tissue attachment. In the gelatin/ß-TCP/rhFGF-2 sites, new bone exhibited many haversian canals and circumferential lamellae as well as remarkably thick periosteum with blood vascularization and hypercellularity. CONCLUSION: Within the limitations of this study, rhFGF-2 in gelatin/ß-TCP sponges exhibits an increased potential to support periodontal wound healing/regeneration in canine recession-type defects.

Solvothermal synthesis of nanoporous TiO2: the impact on thin-film composite membranes for engineered osmosis application.

In the current study, the impact of self-synthesized nanoporous titanium oxide (NT) on the morphology, performance and fouling of a polyamide (PA) thin-film composite (TFC) membrane was investigated when the membrane was applied for engineering osmosis (EO). The nanoporous structure and the spindle-like shape of NT were revealed through transmission electron microscopy (TEM), while the AATPS modification of NT was verified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results of x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) confirmed the presence of modified NT (mNT) in the PA dense active layer of the TFC membrane. The outgrowth of the 'leaf-like' structure, upon mNT loading, at the surface of the PA layer was observed by field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The TFC membrane prepared with 0.05 wt% mNT loading in the organic phase showed the water flux of 26.4 l m(-2) h(-1) when tested in the forward osmosis (FO) mode using 0.5M and 10 mM NaCl solution as the draw and feed solution, respectively. Moreover, the TFC-mNT membrane also demonstrated an intensified antifouling property against organic foulant during FO application and it was possible to retrieve the initial water flux almost completely with a simple water-rinsing process.

Preparation and characterization of a novel highly hydrophilic and antifouling polysulfone/nanoporous TiO2 nanocomposite membrane.

In this research, novel ultrafiltration nanocomposite membranes were prepared by incorporating self-synthesized nanoporous titanium dioxide (NTiO2) nanoparticles into polysulfone. The surface of the nanoparticle was treated with a silane-based modifier to improve its distribution in the host polymer. Atomic-force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, transmission electron microscopy, energy-dispersive x-ray spectroscopy, porosity and contact angle tests were conducted to characterize the properties of the particles as well as the fabricated nanocomposite membranes. The effects of the nanoparticle incorporation were evaluated by conducting ultrafiltration experiments. It was reported that the membrane pure water flux was increased with increasing NTiO2 loading owing to the high porosity of the nanoparticles embedded and/or formation of enlarged pores upon addition of them. The antifouling capacity of the membranes was also tested by ultrafiltration of bovine serum albumin fouling solution. It was found that both water flux and antifouling capacity tended to reach desired level if the NTiO2 added was at optimized loading.

Ridge augmentation using recombinant human fibroblast growth factor-2 with biodegradable gelatin sponges incorporating ß-tricalcium phosphate: a preclinical study in dogs.

BACKGROUND AND OBJECTIVE: Fibroblast growth factor-2 (FGF-2) regulates the proliferation and differentiation of osteogenic cells, resulting in the promotion of bone formation. Biodegradable gelatin sponges incorporating ß-tricalcium phosphate (ß-TCP) have been reported as a scaffold, which has the ability to control growth factor release, offering sufficient mechanical strength and efficient migration of mesenchymal cells. In this study, we evaluated the effects of the combined use of recombinant human FGF-2 (rhFGF-2) and gelatin/ß-TCP sponge on ridge augmentation in dogs. MATERIAL AND METHODS: Six male beagle dogs were used in this study. Twelve wk after tooth extraction, bilateral 10 × 5 mm (width × depth) saddle-type defects were created 3 mm apart from the mesial side of the maxillary canine. At the experimental sites, the defects were filled with gelatin/ß-TCP sponge infiltrated with 0.3% rhFGF-2, whereas gelatin/ß-TCP sponge infiltrated with saline was applied to the control sites. Eight wk after surgery, qualitative and quantitative analyses were performed. RESULTS: There were no signs of clinical inflammation at 8 wk after surgery. Histometric measurements revealed that new bone height at the experimental sites (2.98 ± 0.65 mm) was significantly greater than that at the control sites (1.56 ± 0.66 mm; p = 0.004). The total tissue height was greater at the experimental sites (6.62 ± 0.66 mm) than that at the control sites (5.95 ± 0.74 mm), although there was no statistical significant difference (p = 0.051). Cast model measurements revealed that the residual defect height at the experimental sites (2.31 ± 0.50 mm) was significantly smaller than that at the control sites (3.51 ± 0.78 mm; p = 0.012). CONCLUSION: The combined use of rhFGF-2 and gelatin/ß-TCP sponge promotes ridge augmentation in canine saddle-type bone defects.

Effect of a tunnel-structured ß-tricalcium phosphate graft material on periodontal regeneration: a pilot study in a canine one-wall intrabony defect model.

BACKGROUND AND OBJECTIVE: Tissue regeneration is affected by the porosity, chemical properties and geometric structure of graft materials. Regeneration of severe periodontal defects, such as one-wall intrabony defects, is difficult because of reduced tissue support, and bone grafts are commonly used in such cases. In the present study, a tunnel-structured ß-tricalcium phosphate (tunnel ß-TCP) graft material designed to stimulate bone formation was fabricated. The objective of this pilot study was to evaluate the effect of this graft material on periodontal regeneration in one-wall intrabony defects in dogs. MATERIAL AND METHODS: Six male beagle dogs were used in this study. First, the mandibular second and third incisors were extracted. Experimental surgery was performed 12 wk after tooth extraction. Bilateral 4 × 8 mm (width × depth) one-wall intrabony defects were created in the mesial side of the mandibular canines. At the experimental sites, the defects were filled with tunnel ß-TCP, whereas the control defects were left empty. Twelve weeks after surgery, qualitative and quantitative histological analyses were performed. RESULTS: There were no signs of clinical inflammation 12 wk after surgery. Coronal extension indicative of new bone formation was higher at the experimental sites than at the control sites, although the differences between both the sites in the newly formed cementum and connective tissue attachment were not significant. Newly formed periodontal ligament and cementum-like tissue were evident along the root surface at the experimental sites. The inner surface of the tunnels was partially resorbed and replaced with new bone. New blood vessels were observed inside the lumens of tunnel ß-TCP. CONCLUSION: Tunnel ß-TCP serves as a scaffold for new bone formation in one-wall intrabony defects.

The utility of intra-operative three-dimensional transoesophageal echocardiography for dynamic measurement of stroke volume.

Measurement of left ventricular stroke volume and cardiac output is very important for managing haemodynamically unstable or critically ill patients. The aims of this study were to compare stroke volume measured by three-dimensional transoesophageal echocardiography with stroke volume measured using a pulmonary artery catheter, and to examine the ability of three-dimensional transoesophageal echocardiography to track stroke volume changes induced by haemodynamic interventions. This study included 40 cardiac surgery patients. Haemodynamic variables were measured before and 2 min after haemodynamic interventions, which consisted of phenylephrine 100 µg or ephedrine 5 mg. We used Bland-Altman analysis to assess the agreement between the stroke volume measured by three-dimensional transoesophageal echocardiography and by the pulmonary artery catheter. Polar-plot and 4-quadrant plot analyses were used to assess the trending ability of three-dimensional transoesophageal echocardiography compared with the pulmonary artery catheter. Bias and percentage error were -1.2 ml and 20%, respectively. The concordance rate in the 4-quadrant analysis after phenylephrine and ephedrine administration was 75% and 84%, respectively. In the polar-plot analysis, the angular concordance rate was 66% and 73% after phenylephrine and ephedrine administration, respectively. Three-dimensional transoesophageal echocardiography was clinically acceptable for measuring stroke volume; however, it was not sufficiently reliable for tracking stroke volume changes after haemodynamic interventions.

Systemic vascular resistance has an impact on the reliability of the Vigileo-FloTrac system in measuring cardiac output and tracking cardiac output changes.

BACKGROUND: The aim of this study was to examine the ability of the Vigileo-FloTrac system to measure cardiac output (CO) and track changes in CO induced by increased vasomotor tone, under different states of systemic vascular resistance (SVR). METHODS: Forty patients undergoing cardiac surgery were enrolled. Haemodynamic variables including CO measured by the Vigileo-FloTrac system (version 3.02) (APCO), CO measured by a pulmonary artery catheter (ICO), and SVR index (SVRI) were recorded before (T1) and 2 min after (T2) phenylephrine administration (100 µg). Bland and Altman analysis was used to compare ICO and APCO at T1. We used four-quadrant plots and polar plots to compare the trending abilities between ICO and APCO. Patients were divided into three groups according to the SVRI value at T1, with low (<1200 dyn cm(-5) m(2)), normal (1200-2500 dyn cm(-5) m(2)), and high (>2500 dyn cm(-5) m(2)) SVRI states. RESULTS: A total of 155 paired data were collected. The adjusted percentage error was 46.3%, 26.4%, and 61.4%, and the concordance rate between ΔICO and ΔAPCO was 67.5%, 28.8%, and 7.7% in the low, normal, and high SVRI state, respectively. The polar plot analysis showed that the mean angular bias was -22.3°, -46.0°, and -3.51°, and the radial limits of agreement were 70°, 85°, and 87°, in the low, normal, and high SVRI state, respectively. CONCLUSIONS: These results indicate that the reliability of the Vigileo-FloTrac system to measure CO and track changes in CO induced by phenylephrine administration was not clinically acceptable.

De novo truncating mutations in E6-AP ubiquitin-protein ligase gene (UBE3A) in Angelman syndrome.

Angelman syndrome (AS) is associated with maternal deletions of human chromosome 15q11-q13 and with paternal uniparental disomy for this region indicating that deficiency of an imprinted, maternally expressed gene within the critical interval is the likely cause of the syndrome. Although the gene for E6-AP ubiquitin-protein ligase (UBE3A) was mapped to the critical region for AS, evidence of expression from both parental alleles initially suggested that it was an unlikely candidate gene for this disorder. Because attempts to identify any novel maternally expressed transcripts were unsuccessful and because the UBE3A gene remained within a narrowed AS critical region, we searched for mutations in UBE3A in 11 AS patients without known molecular defects (large deletion, uniparental disomy, or imprinting mutation). This analysis tested the possibility that deficiency of an undefined, maternally expressed transcript or isoform of the UBE3A gene could cause AS. Four mutations were identified including a de novo frameshift mutation and a de novo nonsense mutation in exon 3 and two missense mutations of less certain significance. The de novo truncating mutations indicate that UBE3A is the AS gene and suggest the possibility of a maternally expressed gene product in addition to the biallelically expressed transcript. Intragenic mutation of UBE3A in AS is the first example of a genetic disorder of the ubiquitin-dependent proteolytic pathway in mammals. It may represent an example of a human genetic disorder associated with a locus producing functionally distinct imprinted and biallelically expressed gene products.

Large expansion of the ATTCT pentanucleotide repeat in spinocerebellar ataxia type 10.

Spinocerebellar ataxia type 10 (SCA10; MIM 603516; refs 1,2) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. The gene SCA10 maps to a 3.8-cM interval on human chromosome 22q13-qter (refs 1,2). Because several other SCA subtypes show trinucleotide repeat expansions, we examined microsatellites in this region. We found an expansion of a pentanucleotide (ATTCT) repeat in intron 9 of SCA10 in all patients in five Mexican SCA10 families. There was an inverse correlation between the expansion size, up to 22.5 kb larger than the normal allele, and the age of onset (r2=0.34, P=0.018). Analysis of 562 chromosomes from unaffected individuals of various ethnic origins (including 242 chromosomes from Mexican persons) showed a range of 10 to 22 ATTCT repeats with no evidence of expansions. Our data indicate that the new SCA10 intronic ATTCT pentanucleotide repeat in SCA10 patients is unstable and represents the largest microsatellite expansion found so far in the human genome.

Dental caries and caries-related periodontitis in type 2 diabetic mice.

Diabetic patients are predisposed to periodontal disease as well as dental caries; however, there are contradictory reports about the possible association between dental caries and diabetes. Thus, the authors set out to determine whether diabetes affects onset of dental caries and periodontal disease and to clarify whether dental caries and periodontal disease are associated with each other in diabetic db/db mice. Oral tissue was examined from 68 male mice (diabetic db/db and nondiabetic db/+; aged 20, 30, 40, and 50 weeks) and 20 female mice (db/db and db/+; aged 50 weeks). Macroscopically, caries were seen developing in the diabetic mice by 20 weeks of age. The number of teeth with dental lesions increased with age in the db/db mice at a significantly higher incidence than that of db/+ mice. Histologically, dental caries were detected in 30 of 120 molars in 17 of 20 db/db mice at 50 weeks of age and in 4 of 108 molars in 4 of 18 db/+ mice of the same age. The severity of dental caries in db/db mice was significantly higher than it was in db/+ mice. Dental caries were a primary change that led to bacterial gingivitis and pulpitis. These lesions spread to the dental root and periodontal connective tissue through the apical foramen. Apical periodontitis was more frequent and severe when occurring in close association with dental caries. In conclusion, there is a strong relationship between diabetes and dental caries, but in this model, it is highly probable that the onset of periodontal disease was a secondary change resulting from dental caries.

Quadriceps strength to body weight ratio is a significant indicator for initiating jogging after anterior cruciate ligament reconstruction.

BACKGROUND: Quadriceps strength recovery after anterior cruciate ligament (ACL) reconstruction is an important criterion for progress in rehabilitation and return to sports. The purpose of this study was to determine whether quadriceps strength to body weight ratio (QS/BW) is a significant indicator for initiating jogging after ACL reconstruction. METHODS: Isokinetic quadriceps strength at 60°/s was measured and a jogging trial was completed 3 months after ACL reconstruction with hamstring tendon autograft in 83 patients (36 male, 47 female; mean age, 26.6 ± 12.4 years). Based on the jogging trial results, patients were assigned to either a successful jogging group (mean velocity ≥ 9 km/h) or an unsuccessful jogging group (mean velocity < 9 km/h). The association between QS/BW and successful jogging after surgery was investigated by multivariate logistic regression analysis and the cut-off value was determined by receiver operating characteristic analysis. RESULTS: Forty-four patients (53.0%) were assigned to the successful jogging group and 39 (47.0%) to the unsuccessful jogging group. QS/BW was independently associated with initiating jogging 3 months after surgery. The cut-off value of QS/BW for successful jogging was 1.45 Nm/kg (area under the curve = 0.94; sensitivity = 88.6%, specificity = 87.2%). All of the patients who initiated jogging with QS/BW of > 1.45 Nm/kg at 3 months returned to sports without recurrence or contralateral injury by 10 months after surgery. CONCLUSIONS: QS/BW is a significant indicator for safely initiating jogging 3 months after ACL reconstruction. The cut-off value of QS/BW for initiating jogging was 1.45 Nm/kg.

Splenectomy and antiviral treatment for thrombocytopenic patients with chronic hepatitis C virus infection.

Thrombocytopenic patients with chronic hepatitis C virus (HCV) infection are poor candidates for antiviral treatment with interferon (IFN), but no standard treatment for thrombocytopenia has yet been established. We evaluated the safety of splenectomy and its efficacy for the initiation and continuation of antiviral therapy. From March 2003 to April 2006, 10 patients (mean age 62.5 years) with HCV-related cirrhosis, low platelet count (<==106 000/mm(3)) and splenomegaly (spleen size >==10 cm) underwent splenectomy. Platelet counts significantly increased at 4-8 weeks after splenectomy [pre: 64 200 +/- 6900/mm(3)vs post 209 000 +/- 40 600/mm(3) (P = 0.004)]. No severe operative complications were observed. All patients subsequently received antiviral therapy. Of the eight patients who were infected with HCV genotype 1 and had a high viral load (>==100 KIU/mL), four received combination therapy with pegylated IFNalpha-2b plus ribavirin, and the other four received standard IFNalpha-2b plus ribavirin. One patient infected with HCV genotype 2 and another with HCV genotype 1 and a low viral load (<100 KIU/mL) were treated with pegylated IFNalpha-2a. Six patients achieved sustained virologic response (SVR). Among four patients who failed to achieve SVR, one was given retreatment with pegylated IFN plus ribavirin, and the other three received low-dose long-term IFN therapy. Although this study was small, the treatment results were similar to those for patients without thrombocytopenia and suggested that splenectomy would not reduce the antiviral efficacy of IFNalpha-based treatment.

Advance of age decreases the minimum alveolar concentrations of isoflurane and sevoflurane for maintaining bispectral index below 50.

BACKGROUND: We investigated age-related differences in the minimum alveolar concentration (MAC) of isoflurane and sevoflurane for maintaining bispectral index (BIS) below 50 (MAC(BIS50)). METHODS: One hundred and twenty young (or=70 yr) patients were randomly allocated to one of the six groups. Anaesthesia was induced with isoflurane or sevoflurane in oxygen. After tracheal intubation, we arbitrarily started maintenance of anaesthesia in each group with end-tidal isoflurane and sevoflurane concentrations of 0.8 and 1.2 vol%, respectively. After 10 min at predetermined end-tidal isoflurane or sevoflurane concentrations, BIS was measured for 1 min. MAC(BIS50) of isoflurane or sevoflurane for each group was determined by up-down methodology. RESULTS: MAC(BIS50) of isoflurane in young, middle-aged, and elderly patients was 0.82% end-tidal (95% confidence intervals 0.76-0.88), 0.67% (0.61-0.73), and 0.56% (0.51-0.61), respectively, and that of sevoflurane in young, middle-aged, and elderly patients was 1.28% (1.24-1.32), 0.97% (0.89-1.05), and 0.87% (0.84-0.90), respectively. For both isoflurane and sevoflurane, the MAC(BIS50) was significantly higher (P=0.002 and 0.001, respectively) in young patients and significantly lower (P=0.02 for both) in elderly patients than those in middle-aged patients. CONCLUSIONS: Advance in age significantly decreased the concentrations of isoflurane and sevoflurane required to maintain BIS below 50. BIS correctly reflected age-associated decrease of end-tidal concentrations of isoflurane and sevoflurane required for maintaining adequate depth of anaesthesia during resting state.

A new SOBP-formation method by superposing specially shaped Bragg curves formed by a mini-ridge filter for spot scanning in proton beam therapy.

PURPOSE: We propose a new spread-out Bragg peak (SOBP) formation method for low-energy regions of spot-scanning proton therapy in order to reduce the required number of energy layers while maintaining high dose uniformity, while maintaining the distal falloff as sharp as possible. METHODS: We use only one specially shaped mini-ridge filter (MRF) to create new trapezoidal Bragg curves (TBCs) from very sharp pristine Bragg curves (PBCs) of low-energy proton beams. The TBC has three pre-designed dose regions of proximal, flat-top, and distal components. These components are designed to have nearly equal depth lengths and good linearity. Then, the required SOBP is formed by superposing the TBCs with the correct spacing and beam intensity weights. We then compare the performance of the TBC-based SOBPs with those formed by PBCs. RESULTS: The dose uniformities of the SOBP formed by the proposed method are kept within the design tolerance, and are equivalent to those of conventional SOBPs. The sharpness of the distal falloff is reasonably kept by the deepest TBC. The required number of energy layers is significantly reduced compared with that of conventional PBC-based SOBP. CONCLUSIONS: The proposed method enables shortening of the irradiation time of spot-scanning proton beam therapy in low-energy regions with a reduced number of energy layers. It can be realized by using only one specially shaped MRF, which can be easily installed at any facility.

Impact of Donor Age on Outcome of Intestinal Transplantation in Japan.

BACKGROUND: Donor age for intestinal transplantation (ITx) is somewhat younger than that for other solid organs. Clear criteria for adequate donors have not been established. There is a donor scarcity for ITx in Japan due to the shortage of young donors. METHODS: We reviewed outcomes associated with ITx in Japan based on donor age for cadaveric and living donation. RESULTS: Standardized report forms were sent to all known ITx programs, asking for information on ITxs performed between 1996 and 2016. All programs responded. Patient and graft survival estimates were obtained using the Kaplan-Meier method. Five institutions provided data on 27 grafts in 24 patients. There were 14 cadaveric and 13 living donor transplants. Median donor age for ITxs was 40 (range, 17-60) years. Graft survival at 5 years was 66% for patients >40 years old (n = 18) and 47% for those <40 years old (n = 9), not a statistically significant difference (P = .49). Graft survival at 5 years was 60% in those >50 years old (n = 5) and 57% for those <50 years old (n = 22), again not a significant difference (P = .27). CONCLUSION: There is no difference in survival between for those with donor age <40 vs >40 years. Donor age for ITx can be extended from >40 to up to 50 years, which may help to mitigate the donor shortage. It will be necessary to clarify the donor criteria for ITx through accumulation of further data on ITx.

Three-Year Prospective Follow-up of Potential Pediatric Candidate for Intestinal Transplantation.

Intestinal transplantation (ITx) is a treatment for refractory intestinal failure (IF). However, the indications for and timing of ITx are still controversial because the course of IF is unknown. We performed a prospective multi-institutional cohort study to identify the prognostic factors for referral to an ITx facility. Patients under 18 years of age in Japan who suffered from IF and had received parenteral nutrition for longer than 6 months were enrolled in this study. They were followed up for 3 years. Seventy-two patients were followed. The mean age at the beginning of the study was 7.0 years. Diagnoses were short gut syndrome (n = 25), motility disorder (n = 45), and other (n = 2). The overall 3-year survival rate was 95%. The 3-year survival rate was 86% in patients with intestinal-failure-associated liver disease (IFALD) (n = 6) compared to 97% in those without IFALD (n = 66) (P = .0003). Furthermore, the 3-year survival rates of patients who did and did not meet the criteria for ITx were 82% (n = 11) and 97% (n = 62), respectively (P = .034). Six (44%) of 14 patients whose performance status (PS) was ≥3 at enrollment were dead or still had a PS ≥ 3 at 3 years. This study indicates that IFALD is a poor prognostic factor in pediatric patients with IF. Our indication for ITx, namely the presence of IFALD or loss of more than 2 parenteral nutrition access sites, seems to be applicable.

Polyetherimide hollow fiber membranes for CO2 absorption and stripping in membrane contactor application.

Porous asymmetric polyetherimide (PEI) hollow fiber membranes with various non-solvent additives, e.g. lithium chloride, methanol and phosphoric acid (PA) were prepared for CO2 absorption and stripping process in a membrane contractor. The PEI membranes were characterized via gas permeation, liquid entry pressure of water (LEPw), contact angle and field emission scanning electronic microscopy analysis. The CO2 absorption and stripping performance was evaluated via the membrane contactor system. Addition of non-solvent additives increased the LEPw and membrane porosity of the PEI membrane with the formation of various membrane microstructures and contact angles. Absorption test was performed at 40 °C showed that the PEI-PA membrane produced the highest absorption flux of 2.7 × 10-2 mol m-2 s-1 at 0.85 m s-1 of liquid velocity. Further testing on PEI-PA membrane was conducted on CO2 stripping at 60 °C, 70 °C to 80 °C and the results indicated that the stripping flux was lower compared to the absorption flux. Stripping tests at 80 °C produced the highest stripping flux which might due to the increase in equilibrium partial pressure of CO2 in the liquid absorbent. Modification of PEI membrane via incorporation of additive can enhanced the performance of a membrane contactor via increasing the absorption and stripping flux.

Carbamyl phosphate synthetase I deficiency. One base substitution in an exon of the CPS I gene causes a 9-basepair deletion due to aberrant splicing.

Carbamyl phosphate synthetase I (CPS I; EC6,3,4,16) is an autosomal recessive disorder characterized by hyperammonemia. We studied the molecular bases of CPS I deficiency in a newborn Japanese girl with consanguineous parents. Northern and Western blots revealed a marked decrease in CPS I mRNA and enzyme protein but with a size similar to that of the control, respectively. Sequencing of the patient's cDNA revealed a nine-nucleotide deletion at position 832-840. Sequencing analysis of the genomic DNA revealed a G to C transversion at position 840, the last nucleotide of an exon in the splice donor site. This substitution altered the consensus sequence of the splice donor site and the newly cryptical donor site in the exon caused the 9-bp in-frame deletion. This report seems to be the first complete definition of CPS I deficiency, at the molecular level.