Infantile outcome at 3 years of age among monochorionic twins with Type-II or -III selective fetal growth restriction with isolated oligohydramnios who underwent fetoscopic laser photocoagulation.

OBJECTIVE: This study aimed to examine infantile outcomes at 3 years of age with selective fetal growth restriction (sFGR) Types II and III with isolated oligohydramnios who underwent fetoscopic laser photocoagulation (FLP). METHODS: This multicenter prospective cohort study included monochorionic diamniotic twins who underwent FLP for sFGR between 16 and 25 weeks of gestation. The indication for performing FLP was in cases of sFGR Type II or III with oligohydramnios, where the maximal vertical pocket was ≤2 cm among twins with FGR. This was done in the absence of a typical twin-twin transfusion syndrome diagnosis. The primary outcome was the intact survival (IS) rate of infants at the corrected age of 40 weeks and 3 years. IS at the corrected age of 40 weeks was defined as survival without grade III or IV intraventricular hemorrhage or cystic periventricular leukomalacia, and IS at 3 years of age was defined as survival without neurodevelopmental morbidity, including cerebral palsy, neurodevelopmental impairment with a total developmental quotient of ≤70, bilateral deafness, or bilateral blindness. RESULTS: Among 45 patients with sFGR, 30 (66.7%) were classified as having Type II and 15 (33.3%) as Type III sFGR. The prevalence of IS at the corrected age of 40 weeks was 51.1% (n=23) in FGR twins and 95.5% (n=42) in larger twins. The prevalence of IS at 3 years of age was 46.7% (n=21) in FGR twins and 86.4% (n=38) in larger twins. Among the 24 FGR twins who were not diagnosed with IS at 3 years of age, 91.7% (22 of 24 cases) suffered fetal or infantile demise other than miscarriage and neurodevelopmental impairment. All larger twins who were not diagnosed with IS at 3 years of age (n=6, 13.6%) had neurological morbidity, in addition to one case of miscarriage. CONCLUSIONS: FGR twins and larger twins, when subjected to FLP due to sFGR coupled with umbilical artery Doppler abnormalities and isolated oligohydramnios, exhibit low rates of neurological morbidity and low mortality, respectively. Therefore, FLP for Type II or III sFGR with oligohydramnios may be a feasible and preferable management option. This article is protected by copyright. All rights reserved.

Outcome of laser photocoagulation in monochorionic diamniotic twin pregnancy complicated by Type-II selective fetal growth restriction.

OBJECTIVES: To evaluate the outcome of monochorionic diamniotic (MCDA) twins complicated by Type-II selective fetal growth restriction (sFGR) who underwent fetoscopic laser photocoagulation and to validate a previously proposed subclassification system for Type-II sFGR in a large multicenter cohort. METHODS: This retrospective multicenter cohort study included all MCDA twins complicated by Type-II sFGR who underwent laser photocoagulation of placental anastomoses at four large tertiary fetal-care centers between 2006 and 2020. Cases were subclassified according to a recently proposed system based on Doppler evaluation of the ductus venosus (DV) and middle cerebral artery (MCA) into Type-IIA (normal DV flow and MCA peak systolic velocity (PSV) of the growth-restricted fetus) or Type-IIB (absent or reversed flow in the DV during atrial contraction and/or MCA-PSV ≥ 1.5 multiples of the median of the growth-restricted fetus). Demographic characteristics and pregnancy outcomes were compared between the groups. Data are presented as mean ± SD or n (%) as appropriate. P-values < 0.05 were considered statistically significant. RESULTS: A total of 98 patients with MCDA twins met our inclusion criteria, with 56 subclassified as Type IIA and 42 as Type IIB. Demographic characteristics were similar between the groups; however, Type-IIB cases had a significantly earlier gestational age at diagnosis and at laser surgery, as well as larger intertwin estimated fetal weight discordance, which may be a reflection of disease severity. Postnatal survival of the growth-restricted fetus to 30 days of age was significantly lower in Type-IIB compared to Type-IIA cases (23.8% vs 46.4%; P = 0.034). CONCLUSIONS: In MCDA twins complicated by Type-II sFGR and treated with laser photocoagulation of placental anastomoses, preoperative Doppler assessment of the DV and MCA helped identify a subset of patients at increased risk of demise of the growth-restricted fetus following intervention. This study provides valuable information for guiding surgical management and patient counseling. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Prediction of time to delivery by transperineal ultrasound in second stage of labor.

OBJECTIVE: To investigate whether the transperineal sonographic (TPS) parameters angle of progression (AoP) and midline angle (MLA) can predict the time remaining in the second stage of labor. METHODS: We evaluated prospectively women with a singleton pregnancy in cephalic presentation at term between October 2013 and September 2014. TPS volumes were obtained immediately after confirmation by digital vaginal examination of a fully dilated cervix. AoP and MLA were measured offline by analyzing the ultrasound volumes. Progression of labor was evaluated every hour during the second stage. The associations of AoP and MLA with the interval between TPS assessment and delivery were evaluated using multivariable Cox proportional hazards analyses in nulliparous and parous women separately. RESULTS: A total of 557 women were evaluated. An AoP ≥ 160° (adjusted hazard ratio (aHR), 2.52 (95% CI, 1.98-3.19)) and MLA ≤ 10° (aHR, 1.79 (95% CI, 1.35-2.34)) in nulliparous women and an AoP ≥ 150° (aHR, 1.86 (95% CI, 1.34-2.57)) and MLA ≤ 20° (aHR, 1.69 (95% CI, 1.21-2.34)) in parous women were significantly associated with the remaining time in labor. The positive/negative likelihood ratios of AoP, MLA, clinical station (fetal head descent as observed by digital examination) and clinical rotation (fetal head rotation as observed by digital examination) at these cut-off points were 3.6/0.6, 2.0/0.6, 1.6/0.6 and 1.6/0.8, respectively, in nulliparous women, and 2.4/0.6, 1.3/0.7, 7.6/0.5 and 5.2/0.7, respectively, in parous women. CONCLUSION: TPS assessment of AoP and MLA in the second stage of labor was useful for predicting the time remaining in labor and had higher predictive value than did digital vaginal examination in nulliparous women. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Clinical characteristics of monochorionic twins with large hemoglobin level discordance at birth.

OBJECTIVES: To evaluate neonatal outcomes and clinical characteristics of monochorionic diamniotic (MCDA) twins with a large intertwin hemoglobin (Hb) difference at birth. METHODS: This was a retrospective cohort study of MCDA twin gestations delivered at Osaka Medical Center and Research Institute for Maternal and Child Health between 2003 and 2012. Cases of pregnancy termination, acardiac twins or intrauterine death were excluded. A large intertwin Hb difference at birth was defined as > 8.0 g/dL according to the postnatal criteria for twin anemia-polycythemia sequence (TAPS). The intertwin reticulocyte count ratio (RCR) was calculated by dividing the reticulocyte count of the anemic twin by that of the polycythemic twin. Cases with Hb differences were divided into two groups according to the RCR, TAPS when the RCR was > 1.7 and acute fetofetal hemorrhage (AFFH) when the RCR was ≤ 1.7. Neonatal outcomes were compared between the TAPS and AFFH groups. RESULTS: During the study period, 432 MCDA twin pregnancies of a total of 532 born at our hospital were analyzed. There were 12 (2.8%) cases of a large intertwin Hb difference. The median gestational age at birth of these cases was 34 (range, 23-38) weeks, and all were delivered by Cesarean section. There were seven (1.6%) cases of TAPS and five (1.2%) of AFFH. The neonatal survival rate was 91.7%; in one pair of twins with TAPS neonatal death occurred. All (100%) cases with TAPS and two (40%) with AFFH required blood transfusion or partial-exchange transfusion for at least one infant. CONCLUSIONS: Although the incidence of TAPS and AFFH may be low in MCDA twins, many affected neonates required treatment for hematological abnormalities. Delivery of MCDA twins via Cesarean section does not appear to prevent AFFH, despite the absence of labor.

Effects of the tea catechin epigallocatechin gallate on Porphyromonas gingivalis biofilms.

AIMS: The aim of this study was to investigate the effects of tea catechin epigallocatechin gallate (EGCg) on established biofilms and biofilm formation by Porphyromonas gingivalis, a major pathogen of periodontal disease. METHODS AND RESULTS: Biofilm cell survival was measured using adenosine triphosphate (ATP) bioluminescence. In the presence of EGCg, the ATP level in cells of established biofilms was significantly decreased compared to the controls (P < 0·0001). Transmission electron microscopy revealed that EGCg damaged the cell membrane and cell wall of P. gingivalis. Confocal laser-scanning microscopy revealed that the proportion of dead cells was higher in biofilms treated with EGCg. Moreover, the effects of subminimal inhibitory concentrations (MICs) of EGCg on P. gingivalis biofilm formation were dose-dependent (P < 0·0001). CONCLUSION: Our results suggest that EGCg destroys established P. gingivalis biofilms and inhibits biofilm formation. SIGNIFICANCE AND IMPACT OF THE STUDY: Development of chemical control agents against oral biofilms is necessary, because oral biofilms can be only removed using mechanical debridement. This article indicates that EGCg may represent a novel antibiofilm agent that prevents infections involving bacterial biofilms such as periodontitis.

Effect of the addition of rice straw on microbial community in a sewage sludge digester.

Rice straw was added to a sewage sludge digester and its effects on methane production, dewatering characteristics, and microbial communities in the digested sludge were examined by a continuous digestion experiment under mesophilic conditions (35 °C). Stable gas generation was monitored in all digestion experiments. Methane yield from raw sludge, chopped rice straw and softened rice straw were estimated to be 0.27, 0.18 and 0.26 NL/g total solids load, respectively. The capillary suction time of digested sludge was decreased by the addition of rice straw. Archaeal and bacterial communities in the sludge were elucidated by PCR-DGGE (polymerase chain reaction--denaturing gradient gel electrophoresis) targeting 16S rRNA genes. The Shannon index of DGGE profiles indicated that bacterial diversity increased with the addition of softened rice straw. DNA sequences of significant bands of the digested sludge were most closely related to Methanosaeta concilii (97.4% identity) and Methanoculleus bourgensis (100% identity). Meanwhile, those in the co-digested sludge with rice straw were most closely related to Methanosarcina barkeri (98.4% identity) and Methanoculleus bourgensis (99.3% identity). Although both Methanosaeta spp. and Methanosarcina spp. metabolize acetate to methane, Methanosarcina spp. have a competitive advantage at acetate concentrations of >70 mg/L. Results suggested that the quantity of acetate produced during rice straw degradation may change the archaeal community.

Heterotopic pregnancy diagnosed before the onset of severe symptoms: case report.

BACKGROUND: A heterotopic pregnancy (HP) is an extremely rare disease that represents the simultaneous occurrence of two or more implantation sites in the uterus and extrauterus. Early diagnosis of HP is difficult because of the presence of an intrauterine pregnancy (IUP). In most cases, a precise diagnosis was made after symptoms develop through the rupture or bleeding of the ectopic pregnancy (EP). The authors present a case that was successfully diagnosed as an undemonstrative HP. CASE: A 24-year-old multiparous woman became pregnant after taking clomiphene citrate. At ten weeks of pregnancy, an ultrasonography revealed gestational sacs containing fetuses in the uterus and the right adnexal region, respectively. The patient was diagnosed as having a HP and an emergency right tubal resectomy was performed. The IUP progressed normally and the fetus was delivered at 37 weeks of pregnancy. DISCUSSION: Even if a gestational sac can be confirmed in the uterus, a careful ultrasonographic examination should always be considered to determine the presence of a concurrent extrauterine pregnancy.

Multimodal cross-talk of olfactory and gustatory information in the endopiriform nucleus in rats.

The endopiriform nucleus (EPN) is a large group of multipolar cells located in the depth of the piriform cortex (PC). Although many studies have suggested that the EPN plays a role in temporal lobe epilepsy, the normal function of the EPN remains to be elucidated. By using optical imaging of coronal brain slice preparations with voltage-sensitive dye, we found signal propagation from the PC or gustatory cortex (GC) to the EPN in normal medium. In our previous research, we failed to elicit a reliable signal reproducibly in the EPN by single stimulation either to the PC or GC. In our current research, we found that a double-pulse stimulation to either the PC or GC (interpulse interval: 20-100 ms) induced robust signal propagation to the EPN through excitation in the agranular division of the insular cortex (AI), with further extension to the claustrum. Finally, double site paired-pulse stimulation to the PC and GC also evoked excitation in the AI, claustrum, and EPN. These results suggest that the EPN has dual roles: 1) further processing of modality-specific olfactory and gustatory information from the PC and GC, respectively and 2) synergistic integration of PC-derived olfactory information and GC-derived gustatory information.

Mechanical responses and stress fluctuations of a supercooled liquid in a sheared non-equilibrium state.

A steady shear flow can drive supercooled liquids into a non-equilibrium state. Using molecular dynamics simulations under steady shear flow superimposed with oscillatory shear strain for a probe, non-equilibrium mechanical responses are studied for a model supercooled liquid composed of binary soft spheres. We found that even in the strongly sheared situation, the supercooled liquid exhibits surprisingly isotropic responses to oscillating shear strains applied in three different components of the strain tensor. Based on this isotropic feature, we successfully constructed a simple two-mode Maxwell model that can capture the key features of the storage and loss moduli, even for highly non-equilibrium state. Furthermore, we examined the correlation functions of the shear stress fluctuations, which also exhibit isotropic relaxation behaviors in the sheared non-equilibrium situation. In contrast to the isotropic features, the supercooled liquid additionally demonstrates anisotropies in both its responses and its correlations to the shear stress fluctuations. Using the constitutive equation (a two-mode Maxwell model), we demonstrated that the anisotropic responses are caused by the coupling between the oscillating strain and the driving shear flow. Due to these anisotropic responses and fluctuations, the violation of the fluctuation-dissipation theorem (FDT) is distinct for different components. We measured the magnitude of this violation in terms of the effective temperature. It was demonstrated that the effective temperature is notably different between different components, which indicates that a simple scalar mapping, such as the concept of an effective temperature, oversimplifies the true nature of supercooled liquids under shear flow. An understanding of the mechanism of isotropies and anisotropies in the responses and fluctuations will lead to a better appreciation of these violations of the FDT, as well as certain consequent modifications to the concept of an effective temperature.

Antibiofilm effects of azithromycin and erythromycin on Porphyromonas gingivalis.

Antibiotic resistance of biofilm-grown bacteria contributes to chronic infections, such as marginal and periapical periodontitis, which are strongly associated with Porphyromonas gingivalis. Concurrent azithromycin (AZM) administration and mechanical debridement improve the clinical parameters of periodontal tissue in situ. We examined the in vitro efficacy of AZM against P. gingivalis biofilms. The susceptibilities of adherent P. gingivalis strains 381, HW24D1, 6/26, and W83 to AZM, erythromycin (ERY), ampicillin (AMP), ofloxacin (OFX), and gentamicin (GEN) were investigated using a static model. The optical densities of adherent P. gingivalis cells were significantly decreased by using AZM and ERY at sub-MIC levels compared with those of the controls in all the strains tested, except for the effect of ERY on strain W83. AMP and OFX inhibited P. gingivalis adherent cells at levels over their MICs, and GEN showed no inhibition in the static model. The effects of AZM and ERY against biofilm cells were investigated using a flow cell model. The ATP levels of P. gingivalis biofilms were significantly decreased by AZM at concentrations below the sub-MICs; however, ERY was not effective for inhibition of P. gingivalis biofilm cells at their sub-MICs. Furthermore, decreased density of P. gingivalis biofilms was observed three-dimensionally with sub-MIC AZM, using confocal laser scanning microscopy. These findings suggest that AZM is effective against P. gingivalis biofilms at sub-MIC levels and could have future clinical application for oral biofilm infections, such as chronic marginal and periapical periodontitis.

Utility of remnant liver volume for predicting posthepatectomy liver failure after hepatectomy with extrahepatic bile duct resection.

BACKGROUND: Hepatectomy with extrahepatic bile duct resection is associated with a high risk of posthepatectomy liver failure (PHLF). However, the utility of the remnant liver volume (RLV) in cholangiocarcinoma has not been studied intensively. METHODS: Patients who underwent major hepatectomy with extrahepatic bile duct resection between 2002 and 2018 were reviewed. The RLV was divided by body surface area (BSA) to normalize individual physical differences. Risk factors for clinically relevant PHLF were evaluated with special reference to the RLV/BSA. RESULTS: A total of 289 patients were included. The optimal cut-off value for RLV/BSA was determined to be 300 ml/m2. Thirty-two patients (11.1 per cent) developed PHLF. PHLF was more frequent in patients with an RLV/BSA below 300 ml/m2 than in those with a value of 300 ml/m2 or greater: 19 of 87 (22 per cent) versus 13 of 202 (6.4 per cent) (P < 0.001). In multivariable analysis, RLV/BSA below 300 ml/m2 (P = 0.013), future liver remnant plasma clearance rate of indocyanine green less than 0.075 (P = 0.031), and serum albumin level below 3.5 g/dl (P = 0.015) were identified as independent risk factors for PHLF. Based on these risk factors, patients were classified into three subgroups with low (no factors), moderate (1-2 factors), and high (3 factors) risk of PHLF, with PHLF rates of 1.8, 14.8 and 63 per cent respectively (P < 0.001). CONCLUSION: An RLV/BSA of 300 ml/m2 is a simple predictor of PHLF in patients undergoing hepatectomy with extrahepatic bile duct resection.

A direct numerical simulation method for complex modulus of particle dispersions.

We report an extension of the smoothed profile method (SPM) (Y. Nakayama, K. Kim, and R. Yamamoto, Eur. Phys. J. E 26, 361 (2008)), a direct numerical simulation method for calculating the complex modulus of the dispersion of particles, in which we introduce a temporally oscillatory external force into the system. The validity of the method was examined by evaluating the storage G'(ω) and loss G"(ω) moduli of a system composed of identical spherical particles dispersed in an incompressible Newtonian host fluid at volume fractions of Φ = 0 , 0.41, 0.46, and 0.51. The moduli were evaluated at several frequencies of shear flow; the shear flow used here has a zigzag profile, as is consistent with the usual periodic boundary conditions. The simulation results were compared with several experiments for colloidal dispersions of spherical particles.

Clinical impact of a combined therapy of peritoneal dialysis and hemodialysis.

AIMS: Although peritoneal dialysis (PD) is recommended as the first-line treatment for end-stage renal disease, limitations exist to achieving good clinical status when the residual renal function (RRF) has declined. Combined therapy with PD and hemodialysis (HD) is the treatment of choice for patients who cannot control body fluid status and/or cannot obtain adequate solute removal by PD alone. The aim of this study was to evaluate the clinical efficacy of this combined therapy. METHODS: In this retrospective study, 53 patients on PD and diagnosed with underdialysis and/or overhydration with declining RRF were recruited. Parameters of volume control, uremic solute removal, anemia, and predictors for encapsulating peritoneal sclerosis (EPS) were compared before and 1 year after combined therapy. RESULTS: The patients' hydration status improved significantly with reductions in atrial natriuretic peptide and blood pressure. Serum creatinine and beta2 microglobulin also decreased significantly. The hemoglobin level increased remarkably from 8.2 ± 1.6 to 10.7 ± 1.2 g/dl (p < 0.01) and the reticulocyte count also increased significantly, even though at the same time the dose of recombinant human erythropoietin decreased significantly. The dialysate to plasma creatinine ratio obtained from the fast peritoneal equilibration test (PET) decreased significantly from 0.65 ± 0.11 to 0.59 ± 0.13, and the level of interleukin 6 in PET drainage also significantly decreased. Furthermore, serum C-reactive protein and fibrinogen decreased significantly. CONCLUSIONS: Combined therapy with PD and HD is an effective way to control fluid status and to correct inadequate solute removal, leading to improvement in inflammation, peritoneal function and anemia.

Impact of long-acting calcium channel blockers on the prognosis of patients with coronary artery disease with and without chronic kidney disease: a comparison of three drugs.

Calcium channel blockers (CCBs) can prevent cardiovascular events in patients with coronary artery disease (CAD). This study looked retrospectively at the prognosis of CAD in hypertensive patients with CAD who had undergone a coronary angiograph, had been given a CCB (benidipine [n = 66], amlodipine [n = 45], or long-acting nifedipine [n = 31]) on hospital discharge and were then followed up for a mean +/- SD of 5.2 +/- 2.9 years. Systolic/diastolic blood pressure for all 142 patients decreased significantly from a mean +/- SD of 137 +/- 20/74 +/- 15 mmHg to 129 +/- 20/71 +/- 12 mmHg. Major adverse cardiovascular events (MACE) occurred in 15 patients. Chronic kidney disease (CKD) was a significant risk factor for MACE (hazard ratio 2.35, 95% confidence intervals 1.45, 3.80). Benidipine was superior to nifedipine in preventing MACE in patients both with and without CKD. In conclusion, benidipine and amlodipine reduced the frequency of MACE in hypertensive patients with CAD, particularly in those with complicating CKD.

Paralemmin, a prenyl-palmitoyl-anchored phosphoprotein abundant in neurons and implicated in plasma membrane dynamics and cell process formation.

We report the identification and initial characterization of paralemmin, a putative new morphoregulatory protein associated with the plasma membrane. Paralemmin is highly expressed in the brain but also less abundantly in many other tissues and cell types. cDNAs from chicken, human, and mouse predict acidic proteins of 42 kD that display a pattern of sequence cassettes with high inter-species conservation separated by poorly conserved linker sequences. Prenylation and palmitoylation of a COOH-terminal cluster of three cysteine residues confers hydrophobicity and membrane association to paralemmin. Paralemmin is also phosphorylated, and its mRNA is differentially spliced in a tissue-specific and developmentally regulated manner. Differential splicing, lipidation, and phosphorylation contribute to electrophoretic heterogeneity that results in an array of multiple bands on Western blots, most notably in brain. Paralemmin is associated with the cytoplasmic face of the plasma membranes of postsynaptic specializations, axonal and dendritic processes and perikarya, and also appears to be associated with an intracellular vesicle pool. It does not line the neuronal plasmalemma continuously but in clusters and patches. Its molecular and morphological properties are reminiscent of GAP-43, CAP-23, and MARCKS, proteins implicated in plasma membrane dynamics. Overexpression in several cell lines shows that paralemmin concentrates at sites of plasma membrane activity such as filopodia and microspikes, and induces cell expansion and process formation. The lipidation motif is essential for this morphogenic activity. We propose a function for paralemmin in the control of cell shape, e.g., through an involvement in membrane flow or in membrane-cytoskeleton interaction.

mGluR7 facilitates extinction of aversive memories and controls amygdala plasticity.

Formation and extinction of aversive memories in the mammalian brain are insufficiently understood at the cellular and molecular levels. Using the novel metabotropic glutamate receptor 7 (mGluR7) agonist AMN082, we demonstrate that mGluR7 activation facilitates the extinction of aversive memories in two different amygdala-dependent tasks. Conversely, mGluR7 knockdown using short interfering RNA attenuated the extinction of learned aversion. mGluR7 activation also blocked the acquisition of Pavlovian fear learning and its electrophysiological correlate long-term potentiation in the amygdala. The finding that mGluR7 critically regulates extinction, in addition to acquisition of aversive memories, demonstrates that this receptor may be relevant for the manifestation and treatment of anxiety disorders.

2-Tridecanone: A Naturally Occurring Insecticide from the Wild Tomato Lycopersicon hirsutum f.glabratum.

A nonalkaloid insecticide was isolated from the wild tomato Lycopersicon hirsutum f. glabratum and identified as 2-tridecanone, a compound 72 times more abundant in the wild tomato than in the cultivated tomato L. esculentum. Lepidopterous larvae (Manduca sexta and Heliothis zea) and aphids (Aphis gossypii) died when confined on 2-tridecanone-treated filter paper.

Liver cancer: neonatal estrogen enhances induction by a carcinogen.

A single injection of 100 micrograms of estradiol benzoate into newborn rats was followed after weaning by dietary treatment with one of two dosages of the carcinogen N-hydroxy-N-2-fluorenylacetamide. Autopsies 26 weeks later showed a higher incidence of liver cancer in male and, particularly, female rats injected with hormone than in controls. The weights of livers were greater but gonads were smaller in size in the estradiol groups. Endocrine and possibly centralnervous-system factors may play roles in formation of liver tumors.

Human diabetes associated with a mutation in the tyrosine kinase domain of the insulin receptor.

Insulin receptor complementary DNA has been cloned from an insulin-resistant individual whose receptors have impaired tyrosine protein kinase activity. One of this individual's alleles has a mutation in which valine is substituted for Gly996, the third glycine in the conserved Gly-X-Gly-X-X-Gly motif in the putative binding site fo adenosine triphosphate. Expression of the mutant receptor by transfection into Chinese hamster ovary cells confirmed that the mutation impairs tyrosine kinase activity.