Risk of Abemaciclib-induced Liver Injury in Hormone Receptor-positive, HER2-negative Metastatic Breast Cancer: A Retrospective Analysis.

BACKGROUND/AIM: The efficacy of endocrine therapy combined with abemaciclib for hormone receptor-positive, HER2-negative metastatic breast cancer has been established through pivotal clinical trials. However, abemaciclib-induced liver injury (AILI) can be a cause for dose reduction or discontinuation. Therefore, it is critical to understand the risk factors for AILI. PATIENTS AND METHODS: This retrospective study analyzed data from patients who had received abemaciclib combined with endocrine therapy for metastatic breast cancer as first- or second-line therapy at our hospital between December 2018 and October 2021. Relevant data were extracted from their medical records. Logistic regression analysis was performed to identify characteristics associated with AILI. RESULTS: Of the 52 eligible patients, 12 (23%) received an aromatase inhibitor (AI), and 40 (77%) received fulvestrant, concomitantly with abemaciclib. Fifteen (29%) of the patients developed liver injury after starting abemaciclib. Univariate analysis revealed the following risk factors for AILI: age ≥65 years (p=0.047), fatty liver disease (p=0.047), and concomitant use of an AI (p=0.002). Concomitant use of an AI was identified by multivariate analysis as an independent risk factor for AILI [odds ratio (OR)=10.23, 95% confidence interval (CI)=2.02-51.91, p=0.005]. CONCLUSION: Concomitant use of an AI could be the most significant factor associated with increased risk of AILI. Future research on the mechanism by which the use of an AI plus abemaciclib can cause liver injury, and prospective studies to validate our findings regarding AILI risk factors, are warranted.

Interleukin-4 -590C/T gene polymorphism in Egyptian children with acute lower respiratory infection: A multicenter study.

BACKGROUND: Acute lower respiratory infection (ALRI) is the leading cause of child mortality, especially in the developing world. Polymorphisms in the interleukin 4 (IL-4) gene have been linked to a variety of human diseases. OBJECTIVES: To investigate whether the IL-4 -590C/T (rs2243250) polymorphism could be a genetic marker for susceptibility to ALRIs in young Egyptian children. METHODS: This was a multicenter study conducted on 480 children diagnosed with pneumonia or bronchiolitis, and 480 well-matched healthy control children. Using PCR-RFLP analysis, we genotyped a -590C/T (rs2243250) single nucleotide polymorphism of the IL-4 gene promoter, meanwhile the serum IL-4concentration was measured by ELISA. RESULTS: The frequency of the IL-4 -590 T/T genotype and T allele were overrepresented in patients with ALRIs in comparison to the control group (OR = 2.0; [95% confidence interval [CI]: 1.38-2.96]; for the T/T genotype) and (OR: 1.3; [95%CI: 1.07-1.56]; for the T allele; P < 0.01). The IL-4 -590 T/T genotype was associated with significantly higher mean serum IL-4 concentration (58.7 ± 13.4 pg/mL) compared to the C/T genotype (47.6 ± 11 pg/mL) and the C/C genotype (34.8 ± 9.6 pg/mL); P < 0.01. CONCLUSION: The IL-4 -590C/T (rs2243250) polymorphism may contribute to susceptibility to ALRIs in young Egyptian children.

Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector.

We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.

Unique recognition style of tRNA(Leu) by Haloferax volcanii leucyl-tRNA synthetase.

The recognition manner of tRNA(Leu), a class II tRNA characterized by a long variable arm, by leucyl-tRNA synthetase from an extreme halophilic archaea, Haloferax volcanii, was studied using the in vitro transcription system. It was found that the discriminator base (A73) and the long variable arm, especially the specific loop sequence A47CG47D and U47H at the base of this helix, are significant for recognition by LeuRS. An appropriate stem length of the variable arm was also required. Base substitutions in the anticodon arm did not affect the leucylation activity. Transplantation of both the discriminator base and the variable arm of tRNA(Leu) was not sufficient to introduce leucylation activity to tRNA(Ser). Insertion of an additional nucleotide into the D-loop, which is not involved in the direct interaction with LeuRS, converted tRNA(Ser) to an efficient leucine acceptor. This suggests that differences in the tertiary structure play a key role in eliminating tRNA(Ser). The sequence-specific recognition of the long variable arm of tRNA(Leu) has not been observed in any of other organisms reported, such as Escherichia coli, yeast or human. On the other hand, the mode of discrimination from non-cognate tRNAs is similar to that in E. coli in that differences in the tertiary structure play a key role. Similarity extends to the substrate stringency, exemplified by a cross-species aminoacylation study showing that no class II tRNAs from E. coli or yeast can be leucylated by H. volcanii LeuRS. Our results have implications for the understanding of the evolution of the recognition system of class II tRNA.

Cross-species aminoacylation of tRNA with a long variable arm between Escherichia coli and Saccharomyces cerevisiae.

Prokaryotes have three amino acid-specific class II tRNAs that possess a characteristic long variable arm, tRNASer, tRNALeuand tRNATyr, while eukaryotes have only two, tRNASerand tRNALeu. Because of such a phylogenetic divergence in the composition of tRNA, the class II tRNA system is a good candidate for studying how the tRNA recognition manner has evolved in association with the evolution of tRNA. We report here a cross-species aminoacylation study of the class II tRNAs, showing the unilateral aminoacylation specificity between Escherichia coli and a yeast, Saccharomyces cerevisiae. Both SerRS and LeuRS from E.coli were unable to aminoacylate yeast class II tRNAs; in contrast, the yeast counterparts were able to aminoacylate E.coli class II tRNAs. Yeast seryl-tRNA synthetase was able to aminoacylate not only E.coli tRNASerbut also tRNALeuand tRNATyr, and yeast LeuRS was able to aminoacylate not only E.coli tRNALeubut also tRNATyr. These results indicate that the recognition manner of class II tRNA, especially the discrimination strategy of each aminoacyl-tRNA synthetase against noncognate class II tRNAs, is significantly divergent between E.coli and yeast. This difference is thought to be due mainly to the different composition of class II tRNAs in E.coli and yeast.

Only one nucleotide insertion to the long variable arm confers an efficient serine acceptor activity upon Saccharomyces cerevisiae tRNA(Leu) in vitro.

Several tRNA species have a long variable arm composed of over ten nucleotides, which are relevant to those specific to serine, leucine and tyrosine in prokaryotes, while there are only serine and leucine-specific tRNAs in eukaryotes. To clarify the evolutionary aspects of the identity determination mechanism of these tRNAs, the tRNA(Ser) recognition in Saccharomyces cerevisiae was studied. Unmodified tRNA(Leu) transcript had serylation ability of low efficiency, but native tRNA(Leu) did not, indicating that some modification of tRNA(Leu) serves as a negative identity determinant for seryl-tRNA synthetase. Changing the discriminator base did not seriously affect the serine accepting efficiency. The tRNA(Leu) transcript possessing the variable arm of tRNA(Ser) was efficiently aminoacylated with serine. Eventually, it was found that only one nucleotide insertion to the variable arm of tRNA(Leu) was sufficient to confer an efficient serine accepting activity. The mode of serine tRNA recognition is similar to that in Escherichia coli in that the end of the long variable arm, but not the anticodon or discriminator base, is important. However, S. cerevisiae seryl-tRNA synthetase adopts a substantially different mechanism for rejection of tRNA(Leu) from that of its E. coli counterpart.

Recognition system of class II tRNA in Escherichia coli and yeast.

The recognition system of class II tRNA, tRNA(Ser) and tRNA(Leu), in a yeast Saccharomyces cerevisiae was studied using T7 RNA polymerase transcription system. Yeast SerRS recognizes the long variable arm as in E. coli. However, the anticodon loop of tRNA(Leu), which has no effect on leucylation in E. coli, play a key role for recognition by LeuRS. Results suggest that the recognition style of yeast class II tRNA is substantially different from that of E. coli.

The anticodon loop is a major identity determinant of Saccharomyces cerevisiae tRNA(Leu).

The recognition of tRNALeu, one of the class II tRNAs having a long variable arm, by leucyl-tRNA synthetase in Saccharomyces cerevisiae was studied using the T7 transcription system. Exchanging the anticodon arm of tRNALeu but not the D- or T psi C-arm to that of tRNASer seriously affected the leucine accepting activity. Two nucleotides in the anticodon loop, A35 and G37, were found to be important for leucylation. It was also found that the discriminator base, A73, is required for leucylation, and G73 of tRNASer functions as a negative identity determinant for leucyl-tRNA synthetase. Introducing a set of three base substitutions at positions 35, 37 and 73 was sufficient to convert tRNASer into an efficient leucine acceptor. These results indicate that the identity elements of tRNALeu lie at the second position of the anticodon and the 3' adjacent to the anticodon as well as the discriminator position. Such a sequence specific recognition manner is significantly different from that of Escherichia coli, in which not the anticodon but the tertiary structural elements play a key role in discriminating from other class II tRNAs. The leucine system is the first example which shows that the requirement of the anticodon sequence is variable among species.

[Study of imipenem/cilastatin sodium in the perinatal period].

The placental passage and therapeutic efficacy of imipenem/cilastatin sodium (IPM/CS) were studied in the perinatal period. The results obtained are summarized as follows: 1. The mean biological half-life of IPM in maternal serum was 30 minutes. 2. The umbilical cord serum concentration of IPM was about 70% of that in maternal serum after 30 minutes. 3. A significant level of IPM was found in the amniotic fluid. The amniotic fluid concentration of IPM was over 1 micrograms/ml at 45 minutes after administration and equal to that in maternal serum at about 90 minutes. 4. In 4 patients, the time course of placental transfer of IPM was investigated. The level of IPM in amniotic fluid was higher than that in maternal serum at 90 minutes after administration and gradually increased afterward. 5. The level of IPM was 3.96 micrograms/g in the fetal membranes at 17 minutes after administration. 6. In the treatment of 12 patients with perinatal infections, the preparation showed excellent efficacies in 3 patients and good efficacies in 7 patients. 7. An adverse effect (vomiting) was observed in only one patient. In conclusion, this drug showed satisfactory placental transfer as well as sufficient safety and excellent efficacy in the treatment of perinatal infections.

[Pharmacokinetic and clinical studies on imipenem/cilastatin sodium in the perinatal period. A study of imipenem/cilastatin sodium in the perinatal co-research group].

Pharmacokinetic and clinical studies on imipenem/cilastatin sodium (IPM/CS) in the perinatal period were carried out, and the results obtained are summarized below. 1. IPM/CS transfers to umbilical cord plasma and amniotic fluid were effective. Passage of IPM/CS into mother's milk was as little as with other beta-lactam antibiotics. 2. Among 81 patients with perinatal infections, clinical efficacies were excellent in 16 patients, good in 62, poor in 3, with an efficacy rate of 96.3%. In addition, IPM/CS was effective in 6 patients for prophylaxis. 3. Out of 82 isolates examined for bacterial responses, 69 isolates were eradicated and 8 isolates were decreased. Especially, of 13 isolates of Enterococcus faecalis, 12 were eradicated. 4. In 109 patients administered with IPM/CS, vomiting was observed in 1 patient. No abnormal laboratory test values were observed. 5. IPM/CS was an effective and safe new antibiotic in perinatal infections. We recommend a normal dose of IPM/CS of 0.5 g/0.5 g twice a day and a dose for severe infections of 1 g/1 g twice a day in the perinatal period.

[Pharmacokinetic, bacteriological and clinical studies of cefuzonam in the field of obstetrics and gynecology. Study group of cefuzonam in the field of obstetrics and gynecological infections].

A multi-center open study was conducted to investigate cefuzonam (CZON, L-105) regarding to its pharmacokinetic, bacteriological and clinical aspects in the field of obstetrics and gynecology with the participation of 31 medical institutions and the related facilities. The results are summarized as follows. 1. Peak MICs of CZON for Staphylococcus aureus, coagulase (-) staphylococci, Escherichia coli, Klebsiella pneumoniae, Bacteroides fragilis group, Peptostreptococcus spp. isolated from obstetrical and gynecological infections with relatively high frequencies were 0.39, 0.20, 0.024, 0.024-0.05, 12.5, 0.20 microgram/ml, respectively, with an inoculum size of 10(6) CFU/ml. 2. When 1 g of CZON was given through bolus injection, the maximum concentration (Cmax) of CZON in pelvic dead space exudate was 18.7 micrograms/ml at 60.9 minutes (Tmax) after the injection; Cmax's in all female genital tissues were observed at 0.6-27.9 minutes and ranged from 11.9-26.3 micrograms/g. The Cmax 8.3 micrograms/ml, in the pelvic dead space exudate was noted at 97.0 minutes after the end of the intravenous drip infusion of 1 g over 1 hour, and Cmax's in genital tissues were 14.3-30.0 micrograms/g at the end of infusion. With 1 hour drip infusion of 2 g, Cmax's in genital tissues were 35.0-53.9 micrograms/g at the end of infusion. 3. The clinical efficacy of CZON was evaluated in 206 evaluable patients with obstetric and gynecologic infections. Efficacy rates classified by types of infections were 97.1% (67/69) for intrauterine infections, 81.6% (31/38) for intrapelvic infections, 91.8% (45/49) for adnexitis, 95.2% (20/21) for infections of the external genital organs and 86.2% (25/29) for other infections. 4. Side effects were observed in 7 of the 262 patients: eruption in 6 cases, itching in 2, diarrhea in 1. Abnormal laboratory test values were noted in 9 of the 256 patients. Most of them were slight elevation of hepatic function values. CZON showed satisfactory clinical efficacy and potent antibacterial activity, hence it appears that CZON will be a very useful antibiotic for obstetric and gynecologic infections.

[Basic and clinical studies on ceftriaxone in perinatal infections].

Basic and clinical investigations were conducted on ceftriaxone (CTRX), a cephem antibiotic with a wide antibacterial spectrum and with especially high activity against Gram-negative bacteria. The results obtained are summarized as follows: 1. CTRX, following intravenous drip infusion of 1 g, had a serum half-life of 5.8 hours, which is longer than that of any other existing cephem antibiotics. 2. The level of CTRX in the umbilical cord serum 6 hours after intravenous drip infusion of 1 g was at a satisfactory level, 15 micrograms/ml. 3. The CTRX was remarkably effective or effective in 9 cases, and the activity was high even in cases where penicillin or other third-generation cephems were ineffective. These results seem to indicate that CTRX may be effective in perinatal and intrauterine fetal infections.