Differential diagnosis of Crohn's disease and intestinal tuberculosis based on ATR-FTIR spectroscopy combined with machine learning

BACKGROUND

Crohn's disease (CD) is often misdiagnosed as intestinal tuberculosis (ITB). However, the treatment and prognosis of these two diseases are dramatically different. Therefore, it is important to develop a method to identify CD and ITB with high accuracy, specificity, and speed.

AIM

To develop a method to identify CD and ITB with high accuracy, specificity, and speed.

METHODS

A total of 72 paraffin wax-embedded tissue sections were pathologically and clinically diagnosed as CD or ITB. Paraffin wax-embedded tissue sections were attached to a metal coating and measured using attenuated total reflectance fourier transform infrared spectroscopy at mid-infrared wavelengths combined with XGBoost for differential diagnosis.

RESULTS

The results showed that the paraffin wax-embedded specimens of CD and ITB were significantly different in their spectral signals at 1074 cm-1 and 1234 cm-1 bands, and the differential diagnosis model based on spectral characteristics combined with machine learning showed accuracy, specificity, and sensitivity of 91.84%, 92.59%, and 90.90%, respectively, for the differential diagnosis of CD and ITB.

CONCLUSION

Information on the mid-infrared region can reveal the different histological components of CD and ITB at the molecular level, and spectral analysis combined with machine learning to establish a diagnostic model is expected to become a new method for the differential diagnosis of CD and ITB.

[Efficacy analysis of hepatic arterial infusion chemotherapy combined with targeted and immune therapy followed by 125I seeds implantation in the treatment of hepatocellular carcinoma with portal vain tumor thrombus]

Objective: To investigate the safety and efficacy of Hepatic Arterial Infusion Chemotherapy(HAIC) combined with targeted and immune therapy followed by 125I seeds implantation in portal vain tumor thrombus (PVTT) in the treatment of hepatocellular carcinoma(HCC) with PVTT. Methods: A retrospective study was performed on the clinical data of 21 patients [ (11 men, 10 women) aged 34-73 (52.6±13.7) years] with HCC with PVTT in The First Affiliated Hospital of Zhengzhou University from October 2020 to October 2022, all of them were treated with HAIC plus targeted and immune therapy,and 125I seeds implanted into PVTT. The patients were followed up to January 2023, the efficacy was evaluated according to the modified version of the solid tumor efficacy evaluation criteria (mRECIST). The progression-free survival (PFS) rate, overall survival(OS) rate and portal tumor thrombus control rate at 3, 6, 12 and 18 months after treatment were recorded, and PFS and OS time were followed up. The changes of liver function, AFP, coagulation function and adverse events were observed. Results: Each patient received 2 to 7 (mean: 3.3±1.2) cycles of HAIC. 10-37 seeds (mean:16.6±6.7) were implanted per patients. The median follow-up time was 15 (range from 5 to 25) months.During the follow-up time, 15 patients showed progression and 6 patients died, and the PFS rates at 3, 6, 12, and 18 months after treatment were 90.5%, 71.4%, 42.9%, and 23.8%, respectively, and at 3, 6, 12, and 18-month OS rates were 100%, 100%, 81.0%, and 61.9%, respectively.The PVTT control rates at 3, 6, and 12 months were 90.5%, 90.5%, and 62.5%, respectively. Overall efficacy evaluation of CR rate 0, PR rate 47.6% (10/21), SD rate 38.1% (8/21), and PD rate 14.3% (3/21). The total incidence of treatment-related adverse events was 100%.Grade 3 treatment related adverse events were observed for 4 cases, the rest wereⅠtoⅡadverse events. Right upper abdominal pain, fever and hemorrhage in liver capsule related to the procedures were observed in 11(52.4%), 5(23.8%) and 3(14.3) patients, respectively. Conclusion: HAIC combined with targeted and immune therapy followed by 125I seeds implantation in PVTT is a safe and efficacy therapy for HCC with PVTT.

Advances in Innate Immunity to Overcome Immune Rejection during Xenotransplantation

Transplantation is an effective approach for treating end-stage organ failure. There has been a long-standing interest in xenotransplantation as a means of increasing the number of available organs. In the past decade, there has been tremendous progress in xenotransplantation accelerated by the development of rapid gene-editing tools and immunosuppressive therapy. Recently, the heart and kidney from pigs were transplanted into the recipients, which suggests that xenotransplantation has entered a new era. The genetic discrepancy and molecular incompatibility between pigs and primates results in barriers to xenotransplantation. An increasing body of evidence suggests that innate immune responses play an important role in all aspects of the xenogeneic rejection. Simultaneously, the role of important cellular components like macrophages, natural killer (NK) cells, and neutrophils, suggests that the innate immune response in the xenogeneic rejection should not be underestimated. Here, we summarize the current knowledge about the innate immune system in xenotransplantation and highlight the key issues for future investigations. A better understanding of the innate immune responses in xenotransplantation may help to control the xenograft rejection and design optimal combination therapies.

The importance of vitellogenin receptors in the oviposition of the pond wolf spider, Pardosa pseudoannulata

Vitellogenin receptor (VgR) is crucial for vitellogenin (Vg) uptake by oocytes. VgR is less known in Arachnida, especially in spiders. Different from only one VgR in an arthropod species, two VgRs, VgR-1 and VgR-2, were found in the pond wolf spider, Pardosa pseudoannulata. Both VgRs had the typical domains of the low-density lipoprotein receptor family except for the absence of the ligand-binding domain 1 in VgR-2. Spatiotemporal expression profiles showed that two VgR genes were consistently highly expressed in females and their ovaries, but VgR-1 was 48-fold that of VgR-2 in ovaries. The transcriptional level of VgR-1 was significantly downregulated by RNAi, but it did not work for VgR-2 although several trials were performed. Vg-1 and Vg-2 might be the ligands of VgR-1 because their expressions were also decreased in the dsVgR-1-treated females. Silencing VgR-1 prolonged the pre-oviposition period by 56 h. The expression of VgRs and Vgs were upregulated by juvenile hormones (JHs), which suggested that JHs were the essential factors to vitellogenesis in the spider. The present study revealed the importance of VgR-1 in the spider oviposition, which will improve the understanding on VgR physiological functions in spiders.

Hydrogen therapy can be used to control tumor progression and alleviate the adverse events of medications in patients with advanced non-small cell lung cancer

Chemotherapy, targeted therapy, and immunotherapy are used against advanced non-small cell lung cancer. A clinically efficacious method for relieving the adverse events associated of such therapies is lacking. Fifty-eight adult patients were enrolled in our trial to relieve pulmonary symptoms or the adverse events of drugs. Twenty patients who refused drug treatment were assigned equally and randomly to a hydrogen (H₂)-only group and a control group. According to the results of tumor-gene mutations and drug-sensitivity tests, 10, 18, and 10 patients were enrolled into chemotherapy, targeted therapy, and immunotherapy groups in which these therapies were combined with H₂-therapy, respectively. Patients underwent H₂ inhalation for 4–5 hours per day for 5 months or stopped when cancer recurrence. Before study initiation, the demographics (except for tumor-mutation genes) and pulmonary symptoms (except for moderate cough) of the five groups showed no significant difference. During the first 5 months of treatment, the prevalence of symptoms of the control group increased gradually, whereas that of the four treatment groups decreased gradually. After 16 months of follow-up, progression-free survival of the control group was lower than that of the H₂-only group, and significantly lower than that of H₂ + chemotherapy, H₂ + targeted therapy, and H₂ + immunotherapy groups. In the combined-therapy groups, most drug-associated adverse events decreased gradually or even disappeared. H₂ inhalation was first discovered in the clinic that can be used to control tumor progression and alleviate the adverse events of medications for patients with advanced non-small cell lung cancer. This study was approved by the Ethics Committee of Fuda Cancer Hospital of Jinan University on December 7, 2018 (approval No. Fuda20181207), and was registered at ClinicalTrials.gov (Identifier: NCT03818347) on January 28, 2019.

Two weeks of hydrogen inhalation can significantly reverse adaptive and innate immune system senescence patients with advanced non-small cell lung cancer: a self-controlled study

Following standard treatments, the traditional model for enhancing anti-tumor immunity involves performing immune reconstitution (e.g., adoptive immune cell therapies or immunoenhancing drugs) to prevent recurrence. For patients with advanced non-small cell lung cancer, we report here on two objectives, the immunosenescence for advanced non-small cell lung cancer and hydrogen gas inhalation for immune reconstitution. From July 1^st to September 25^th, 2019, 20 non-small cell lung cancer patients were enrolled to evaluate the immunosenescence of peripheral blood lymphocyte subsets, including T cell, natural killer/natural killer T cell and gamma delta T cell. Two weeks of hydrogen inhalation was performed during the waiting period for treatment-related examination. All patients inhaled a mixture of hydrogen (66.7%) and oxygen (33.3%) with a gas flow rate of 3 L/min for 4 hours each day. None of the patients received any standard treatment during the hydrogen inhalation period. After pretreatment testing, major indexes of immunosenescence were observed. The abnormally higher indexes included exhausted cytotoxic T cells, senescent cytotoxic T cells, and killer Vδ1 cells. After 2 weeks of hydrogen therapy, the number of exhausted and senescent cytotoxic T cells decreased to within the normal range, and there was an increase in killer Vδ1 cells. The abnormally lower indexes included functional helper and cytotoxic T cells, Th1, total natural killer T cells, natural killer, and Vδ2 cells. After 2 weeks of hydrogen therapy, all six cell subsets increased to within the normal range. The current data indicate that the immunosenescence of advanced non-small cell lung cancer involves nearly all lymphocyte subsets, and 2 weeks of hydrogen treatment can significantly improve most of these indexes. The study was approved by the Ethics Committee of Fuda Cancer Hospital, Jinan University in China (approval No. Fuda20181207) on December 7^th, 2018, and was registered on ClinicalTrials.gov (ID: NCT03818347) on January 24^th, 2019.

"Real world survey" of hydrogen-controlled cancer: a follow-up report of 82 advanced cancer patients

Advanced cancer treatment is a huge challenge and new ideas and strategies are required. Hydrogen exerts antioxidant and anti-inflammatory effects that may be exploited to control cancer, the occurrence and progression of which is closely related to peroxidation and inflammation. We conducted a prospective follow-up study of 82 patients with stage III and IV cancer treated with hydrogen inhalation using the "real world evidence" method. After 3-46 months of follow-up, 12 patients died in stage IV. After 4 weeks of hydrogen inhalation, patients reported significant improvements in fatigue, insomnia, anorexia and pain. Furthermore, 41.5% of patients had improved physical status, with the best effect achieved in lung cancer patients and the poorest in patients with pancreatic and gynecologic cancers. Of the 58 cases with one or more abnormal tumor markers elevated, the markers were decreased at 13-45 days (median 23 days) after hydrogen inhalation in 36.2%. The greatest marker decrease was in achieved lung cancer and the lowest in pancreatic and hepatic malignancies. Of the 80 cases with tumors visible in imaging, the total disease control rate was 57.5%, with complete and partial remission appearing at 21-80 days (median 55 days) after hydrogen inhalation. The disease control rate was significantly higher in stage III patients than in stage IV patients (83.0% and 47.7%, respectively), with the lowest disease control rate in pancreatic cancer patients. No hematological toxicity was observed although minor adverse reactions that resolved spontaneously were seen in individual cases. In patients with advanced cancer, inhaled hydrogen can improve patients' quality-of-life and control cancer progression. Hydrogen inhalation is a simple, low-cost treatment with few adverse reactions that warrants further investigation as a strategy for clinical rehabilitation of patients with advanced cancer. The study protocol received ethical approval from the Ethics Committee of Fuda Cancer Hospital of Jinan University on December 7, 2018 (approval number: Fuda20181207).

[Bibliometric analysis on research hotspots on HIV post-exposure prophylaxis related articles in the world, 2000-2017]

Objective: To analyze and reveal the distribution, research hotspots and study trend of worldwide published articles correlated with HIV/AIDS post-exposure prophylaxis (PEP), and provide information for related studies in China. Methods: CiteSpace software 5.1 was used to visualize all related papers in the web of science database published during 2000-2017. Results: The average growth rate of international PEP-related papers was 10.78%,and number of published papers in 2016 was highest (n=34), relevant research hotspots have shifted from the prevention of occupational HIV exposure to the prevention of non-occupational HIV exposure in group at high risk, such as MSM, in recent years. Clustering analysis classified research hotspots into three categories, including risk reduction through enhanced intervention, current status of global HIV PEP and German-Austrian Recommendation. Conclusions: Non-occupational HIV PEP in groups at high-risk, especially MSM, has received increasing attention in recent years, the research of PEP mainly focus on improving the awareness and use of PEP in MSM and compliance in the course of medication. In the context of severe HIV epidemic in MSM without effective control in China, PEP should be strengthened to assess and explore the risk of HIV infection in MSM to provide reference for medical personnel and related departments to implement HIV non-occupation exposure blockade and formulate PEP medication.

O-GlcNAcylation regulates breast cancer metastasis via SIRT1 modulation of FOXM1 pathway

Tumors utilize aerobic glycolysis to support growth and invasion. However, the molecular mechanisms that link metabolism with invasion are not well understood. The nutrient sensor O-linked-β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) modifies intracellular proteins with N-acetylglucosamine. Cancers display elevated O-GlcNAcylation and suppression of O-GlcNAcylation inhibits cancer invasion and metastasis. Here, we show that the regulation of cancer invasion by OGT is dependent on the NAD⁺-dependent deacetylase SIRT1. Reducing O-GlcNAcylation elevates SIRT1 levels and activity in an AMPK-dependent manner. Reduced O-GlcNAcylation in cancer cells leads to SIRT1-mediated proteasomal degradation of oncogenic transcription factor FOXM1 in a MEK/ERK-dependent manner. SIRT1 is critical for OGT-mediated regulation of FOXM1 ubiquitination and reducing SIRT1 activity reverses OGT-mediated regulation of FOXM1. Moreover, we show that SIRT1 levels are required for OGT-mediated regulation of invasion and metastasis in breast cancer cells. Thus, O-GlcNAcylation is a central component linking metabolism to invasion and metastasis via a SIRT1/ /FOXM1 axis.

D-ribose-5-phosphate isomerase from spinach: heterologous overexpression, purification, characterization, and site-directed mutagenesis of the recombinant enzyme

A cDNA encoding spinach chloroplastic ribose-5-phosphate isomerase (RPI) was cloned and overexpressed in Escherichia coli, and a purification scheme for the recombinant enzyme was developed. The purified recombinant RPI is a homodimer of 25-kDa subunits and shows kinetic properties similar to those of the homodimeric enzyme isolated from spinach leaves (A. C. Rutner, 1970, Biochemistry 9, 178-184). Phosphate, used as a buffer in previous studies, is a competitive inhibitor of RPI with a K(i) of 7.9 mM. D-Arabinose 5-phosphate is an effective inhibitor, while D-xylulose-5 phosphate is not, indicating that the configuration at carbon-3 contributes to substrate recognition. Although D-arabinose 5-phosphate binds to RPI, it is not isomerized, demonstrating that the configuration at carbon-2 is crucial for catalysis. Alignment of RPI sequences from diverse sources showed that only 11 charged amino acid residues of the 236-residue subunit are conserved. The possible function of four of these residues was examined by site-directed mutagenesis. D87A, K100A, and D90A mutants show greatly diminished k(cat) values (0. 0012, 0.074, and 0.38% of the wild type, respectively), while E91A retains substantial activity. Only insignificant or moderate changes in K(m) of D-ribose 5-phosphate are observed for D87A, K100A, and D90A, indicating a direct or indirect catalytic role of the targeted residues.

D-Ribulose-5-phosphate 3-epimerase: cloning and heterologous expression of the spinach gene, and purification and characterization of the recombinant enzyme

We have achieved, to our knowledge, the first high-level heterologous expression of the gene encoding D-ribulose-5-phosphate 3-epimerase from any source, thereby permitting isolation and characterization of the epimerase as found in photosynthetic organisms. The extremely labile recombinant spinach (Spinacia oleracea L.) enzyme was stabilized by DL-alpha-glycerophosphate or ethanol and destabilized by D-ribulose-5-phosphate or 2-mercaptoethanol. Despite this lability, the unprecedentedly high specific activity of the purified material indicates that the structural integrity of the enzyme is maintained throughout isolation. Ethylenediaminetetraacetate and divalent metal cations did not affect epimerase activity, thereby excluding a requirement for the latter in catalysis. As deduced from the sequence of the cloned spinach gene and the electrophoretic mobility under denaturing conditions of the purified recombinant enzyme, its 25-kD subunit size was about the same as that of the corresponding epimerases of yeast and mammals. However, in contrast to these other species, the recombinant spinach enzyme was octameric rather than dimeric, as assessed by gel filtration and polyacrylamide gel electrophoresis under nondenaturing conditions. Western-blot analyses with antibodies to the purified recombinant enzyme confirmed that the epimerase extracted from spinach leaves is also octameric.

Roles and microenvironments of tryptophanyl residues of spinach phosphoribulokinase

Phosphoribulokinase is one of several Calvin cycle enzymes that are light-regulated via the ferredoxin-thioredoxin system (R. A. Wolosiuk and B. B. Buchanan, 1978, Arch. Biochem. Biophys. 189, 97-101). Substitution of the only two Trp residues of the enzyme was prompted by the following goals: to identify each tryptophanyl residue with respect to prior classifications as exposed and buried (C. A. Ghiron et al., 1988, Arch. Biochem. Biophys. 260, 267-272); to explore the possible active-site location and function of conserved Trp155, as suggested by sequence proximity to catalytic Asp160 (H. A. Charlier et al., 1994, Biochemistry 33, 9343-9350); and to determine if fluorescence of a Trp residue can serve as a gauge of conformational differences between the reduced (active) and the oxidized (inactive) forms of the enzyme. Emission spectra and acrylamide quenching data demonstrate that Trp155 is solvent exposed, while Trp241 is buried. Kinetic parameters of the W241F mutant are not significantly altered relative to those of wild-type enzyme, thereby discounting any requirement for Trp at position 241. While substitution of Trp155 with Phe or Ala has little impact on Vmax, the Km for Ru5P and ATP are increased substantially; the diminished affinity for ATP is particularly pronounced in the case of the Ala substitution. In further support of an active-site location of Trp155, its fluorescence emission is subject to quenching by nucleotides. Fluorescence quenching of reduced W241F by ATP gives a dissociation constant (Kd) of 37 microM, virtually identical with its Km of 46 microM, and provides for the first time a direct measurement of the interaction of the kinase with product ADP (Kd of 1.3 mM). Fluorescence quenching of oxidized W241F by ATP reveals a Kd of 28 mM; however, this weakened binding does not reflect an altered microenvironment of Trp155, as its steady-state emission and fluorescence lifetimes are unaffected by the oxidation state.

Efficient expression of the gene for spinach phosphoribulokinase in Pichia pastoris and utilization of the recombinant enzyme to explore the role of regulatory cysteinyl residues by site-directed mutagenesis

Phosphoribulokinase (PRK), unique to photosynthetic organisms, is regulated in higher plants by thioredoxin-mediated thiol-disulfide exchange in a light-dependent manner. Prior attempts to overexpress the higher plant PRK gene in Escherichia coli for structure-function studies have been hampered by sensitivity of the recombinant protein to proteolysis as well as toxic effects of the protein on the host. To overcome these impediments, we have spliced the spinach PRK coding sequence immediately downstream from the AOX1 (alcohol oxidase) promoter of Pichia pastoris, displacing the chromosomal AOX1 gene. The PRK gene is now expressed, in response to methanol, at 4-6% of total soluble protein, without significant in vivo degradation of the recombinant enzyme. This recombinant spinach PRK is purified to homogeneity by successive anion-exchange and dye-affinity chromatography and is shown to be electrophoretically and kinetically indistinguishable from the authentic spinach counterpart. Site-specific replacement of all of PRK's cysteinyl residues (both individually and in combination) demonstrates a modest catalytically facilitative role for Cys-55 (one of the regulatory residues) and the lack of any catalytic role for Cys-16 (the other regulatory residue), Cys-244, or Cys-250. Mutants with seryl substitutions at position 55 display non-hyperbolic kinetics relative to the concentration of ribulose 5-phosphate. Sulfate restores hyperbolic kinetics and enhances kinase activity, presumably reflecting conformational differences between the position 55 mutants and wild-type enzyme. Catalytic competence of the C16S-C55S double mutant proves that mere loss of free sulfhydryl groups by oxidative regulation cannot account entirely for the accompanying total inactivation.

The role of an active-site lysyl residue of spinach phosphoribulokinase as explored by site-directed mutagenesis

Based on selective labeling by ATP analogues, Lys68 of the Calvin Cycle enzyme phosphoribulokinase (PRK) from spinach has been assigned to the active-site region [Miziorko et al. (1990), J. Biol. Chem. 265, 3642-3647]. The equivalent position is occupied by lysyl or arginyl residues in the PRK from both prokaryotic and eukaryotic sources, suggesting a requirement for a basic residue at this location. To examine this possibility, we have replaced Lys68 of the spinach enzyme with arginyl, glutaminyl, alanyl, or glutamyl residues by site-directed mutagenesis. All of the mutant enzymes retain substantial kinase activity; and even in the case of the radical substitution by glutamate, the Km values for ATP and ribulose 5-phosphate are not perturbed significantly. Glutamate at position-68 may destabilize tertiary structure, because the yield of this mutant protein from transformed E. coli is quite low compared to that of the other proteins in this series. Despite the active-site proximity of Lys68, our results show that this residue does not play a key role in catalysis or substrate binding.

Genetic diversity and differentiation of indica and japonica rice detected by RFLP analysis

Genetic diversity and differentiation in indica and japonica groups of the cultivated rice (Oryza sativa L.) were studied by assaying DNA restriction fragment length polymorphisms of 12 indica and 14 japonica rice lines digested with three restriction endonucleases. A total of 49 probes were selected to represent the entire RFLP map at intervals of 20-30 cM. It was shown that 95 of the 145 possible probe/enzyme combinations, involving 43 probes and all three enzymes, detected restriction fragment length variation, and the degree of polymorphism varied greatly from one probe/enzyme combination to another. These results demonstrate that indica rice is genetically more diverse than japonica type. Significant differentiation between the two rice groups was detected by 33 probes representing 11 of the 12 rice chromosomes. It was deduced that the processes leading to differentiation involved a combination of molecular events that include base substitutions and insertion/deletions.

Manufacture of diploid/tetraploid chimeric mice

Tetraploid mouse embryos were produced by cytochalasin B treatment. These embryos usually die before completion of embryonic development and are abnormal morphologically and physiologically. The tetraploid embryos can be rescued to develop to maturity by aggregating them with normal diploid embryos to produce diploid/tetraploid chimeric mice. The diploid/tetraploid chimeric embryos are frequently abnormal: the larger the proportion of tetraploid cells, the greater the abnormality. By karyotype analysis and by the use of appropriate pigment cell markers, we have demonstrated that two of our surviving chimeras are in fact diploid/tetraploid chimeras. One surviving chimera is retarded in growth and displays neurological abnormalities. The coat color chimerism suggests that this chimera is about 50% tetraploid. Another chimera with about 10% tetraploid pigment cells in the coat is only slightly retarded in growth and is a fertile male. Tetraploid cells are distributed in many, if not all, tissues of embryos but evidently are physiologically inadequate to support completely normal development and function in the absence of substantial numbers of normal diploid cells.

Comparison of Auxin-induced and Acid-induced Elongation in Soybean Hypocotyl

Acid-induced growth was compared to auxin-induced growth. After a transient pH 4-induced increase in the elongation rate was completed, auxin could still induce an enhanced rate of elongation in soybean (Glycine max) hypocotyl segments. This auxin response occurred both when the medium was changed to pH 6 before auxin addition, and when the auxin was added directly to the pH 4 medium. This postacid response to auxin was persistent, and quite unlike a postacid response to acid, which was again shortlived. One mm N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (pH 7) inhibited the first response to auxin (the first response to auxin being similar to the acid response), but not the second response. This did not appear to be simply a hydrogen ion neutralizing effect, however, since a 50-fold increase in buffer concentration at pH 6 did not inhibit the first response. Decrease in the pH of the external medium, previously shown to occur with excised soybean hypocotyl segments, was not affected by auxin. Furthermore, this pH drop, during which the cells appear to be adjusting their external pH to about 5.4, did not result in an increased rate of elongation. Addition of auxin after the equilibrium pH had been attained did not alter the pH, but it did increase the rate of elongation, eliciting a normal auxin response. It was concluded that hydrogen ions do not mediate in long term auxin-induced elongation in soybean hypocotyl.

Two elongation responses to auxin respond differently to protein synthesis inhibition

The first and second responses to auxin react differently to the inhibition of protein synthesis by cycloheximide. It was determined that the protein with the shortest half-life, among the several necessary for the first response, is different from its counterpart among the several necessary for the second response. Specifically, the protein half-lives are 28 minutes and 11 minutes for the first and second responses, respectively.