[Analysis of clinical manifestations and prognosis of primary systemic light chain amyloidosis with liver involvement].

Objective: To summarize the clinical manifestations and prognostic factors of patients with hepatic amyloidosis in a single center. Methods: The clinical data of 28 primary systemic light chain amyloidosis cases with liver involvement in our center from October 2012 to January 2023 were retrospectively analyzed. The main clinical manifestations and prognostic factors were studied. Statistical analysis were performed using the χ(2) test, Fisher's exact test, Wilcoxon rank test, or Kaplan-Meier survival curve log-rank test according to the different data. Results: The main clinical manifestations of patients with liver involvement were abdominal distension, hepatomegaly, and edema. CD56 and chemokine receptor 4 protein expression accounted for 52% (13/25) and 56% (14/25). 64.3% (9/14) patients were combined with t (11,14), and 21.4% (3/14) patients were positive for 1q21 (+), and no patients were detected with del(17p). Univariate analysis showed that Mayo 2004 and 2012 stages and total bilirubin (TBil) ≥34.2 µmol/L were associated with progression-free survival and overall survival. The median progression-free survival and overall survival were significantly inferior in patients with TBil≥34.2µmol/L group (0.178 years, 0.195 years) than with the TBil<34.2µmol/L group (0.750 years, 3.586 years) (P < 0.05). Conclusion: Mayo stage and hyperbilirubinemia are inferior prognostic factors for patients with primary systemic light chain amyloidosis accompanied with liver involvement.

[Efficacy and safety analysis of a combination regimen with BCL-2 inhibitor in relapsed/refractory primary systemic light chain amyloidosis with t(11;14) from a single center].

Objective: To explore the efficacy and safety of BCL-2 inhibitor-based treatment in patients with relapsed/refractory t (11; 14) primary systemic light chain amyloidosis. Methods: This was a retrospective case series study. Ten patients with relapsed/refractory t(11;14) primary systemic light chain amyloidosis who had all received treatment with a combination regimen including the BCL-2 inhibitor venetoclax from January 2018 to November 2022 at the Hematology Department of Peking University People's Hospital were included. Adverse events, and hematological and organ responses were evaluated. Results: The median age of the ten enrolled patients was 59 (range 41-78) years, and the male to female ratio was 8∶2. Except for one patient, a very good partial or better response was achieved in 8/9 patients and one patient obtained a partial response. The overall response rate was 100%. The median time to achieve a hematological response was 60 (range 24-236) days. At least one organ response was observed in 7/9 patients. With a median follow-up of 18 months, one patient experienced hematological progression and one patient died. Grade 3 adverse events included lymphocytopenia (3 cases), anemia (1 case), diarrhea (1 case), and appendicitis (1 case). One patient died of pulmonary fungal infection two months after completion of treatment, which was not excluded as being treatment related. Conclusion: A combination regimen including BCL-2 inhibitors in patients with relapsed/refractory t(11;14) primary systemic light chain amyloidosis is a potentially safe and effective treatment option that warrants further investigation.

[Short-term efficacy of venetoclax combined with azacitidine in acute myeloid leukemia: a single-institution experience].

Objective: To explore the safety and short-term efficacy of venetoclax combined with azacitidine (Ven+AZA) in previously untreated patients unfit for standard chemotherapy and patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) in China. Methods: A retrospective study was conducted in 60 previously untreated patients unfit for standard chemotherapy and patients with R/R AML who received Ven+ AZA (venetoclax, 100 mg D1, 200 mg D2, 400 mg D3-28; azacitidine, 75 mg/m(2) D1- 7) at the Peking University Institute of Hematology from June 1, 2019 to May 31, 2021. The incidence of adverse events, complete remission (CR) /CR with incomplete hematological recovery (CRi) rate, objective remission rate (ORR) , and minimal residual disease (MRD) status in patients with different risk stratification and gene subtypes were analyzed. Results: The median age of the patients was 54 (18-77) years, 33 (55.0%) were males, and the median follow-up time was 4.8 (1.4-26.3) months. Among the 60 patients, 24 (40.0%) were previously untreated patients unfit for standard chemotherapy, and 36 (60.0%) were R/R patients. The median mumber cycles of Ven+AZA in the two groups were both 1 (1-5) . According to the prognostic risk stratification of the National Comprehensive Cancer Network, it was divided into 8 cases of favorable-risk, 2 cases of intermediate risk, and 14 cases of poor-risk. In previously untreated patients unfit for standard chemotherapy, after the first cycle of Ven+AZA, 17/24 (70.8%) cases achieved CR/CRi, 3/24 (12.5%) achieved partial remission (PR) , and the ORR was 83.3%. Among them, nine patients received a second cycle chemotherapy and two received a third cycle. Among CR/CRi patients, 8/17 (47.1%) achieved MRD negativity after two cycles of therapy. In the R/R group, after the first cycle of Ven+AZA, 21/36 (58.3%) cases achieved CR/CRi (7/21 achieved MRD negativity) , 3 achieved PR, and the ORR was 66.7%. Among R/R patients, 12 were treated for more than two cycles. There were no new CR/CRi patients after the second treatment cycle, and 14 cases (66.7%) achieved MRD negativity. According to the time from CR to hematological recurrence, the R/R group was divided into 12 cases in the favorable-risk group (CR to hematological recurrence ≥18 months) and 24 in the poor-risk group (CR to hematological recurrence<18 months, no remission after one cycle of therapy, and no remission after two or more cycles of therapy) . Eleven of 24 (45.8%) cases achieved CR/CRi after one cycle of Ven+AZA in the poor-risk R/R group, and 10 of 12 (83.3%) achieved CR/CRi in the favorable-risk R/R group, which was significantly superior to the poor-risk group (P=0.031) . After one cycle of treatment, 13 patients with IDH1/2 mutations and 4 that were TP53-positive all achieved CR/CRi. The CR/CRi rate of 18 patients with NPM1 mutations was 77.8%. Five patients with RUNX1-RUNX1T1 combined with KIT D816 mutation (two initial diagnoses and three recurrences) had no remission. Ven+ AZA was tolerable for AML patients. Conclusion: Ven+AZA has acceptable safety in previously untreated patients unfit for standard chemotherapy, patients with R/R AML can achieve a high response rate, and some patients can achieve MRD negativity. It is also effective in NPM1-, IDH1/IDH2-, and TP53-positive patients. The long-term efficacy remains to be observed.

[Observation on the efficacy of consolidation chemotherapy combined with allogeneic natural killer cell infusion in the treatment of low and moderate risk acute myeloid leukemia].

Objective: To evaluate the efficacy of consolidation chemotherapy combined with allogeneic natural killer (NK) cell infusion in the treatment of low or intermediate-risk (LIR) acute myeloid leukemia (AML) . Methods: A cohort of 23 LIR AML patients at hematologic complete remission (CR) received NK cell transfusion combined with consolidation chemotherapy after 3 consolidation courses from January 2014 to June 2019 were reviewed. Control group cases were concurrent patients from Department of Hematology, and their gender, age, diagnosis, risk stratification of prognosis, CR and the number of courses of consolidate chemotherapy before NK cell transfusion were matched with LIR AML patients. Results: A total of 45 times of NK cells were injected into 23 LIR AML patients during 4 to 7 courses of chemotherapy. The median NK cell infusion quantity was 7.5 (6.6-8.6) ×10(9)/L, and the median survival rate of NK cells was 95.4% (93.9%-96.9%) . Among them, the median CD3(-)CD56(+) cell number was 5.0 (1.4-6.4) ×10(9)/L, accounting for 76.8% (30.8%-82.9%) ; The number of CD3(+) CD56(+) cells was 0.55 (0.24-1.74) ×10(9)/L, accounting for 8.8% (4.9%-20.9%) . Before NK cell infusion, the number of patients with positive MRD in the treatment and control groups were 9/23 (39.1%) and 19/46 (41.3%) (χ(2)=0.030, P=0.862) respectively. After NK infusion, There was no significant difference in terms of MRD that went from negative to positive between the treatment and the control groups (14.3% vs 22.2%, χ(2)=0.037, P=0.847) . In the treatment group, 66.7% (6/9) of the MRD were converted from positive to negative, which was significantly higher than that in the control group (10.5%, 2/19) (χ(2)=6.811, P=0.009) . Morphological recurrence occurred in 1 case of MRD negative in the treatment group and 2 cases of MRD positive in the control group. By the end of follow-up, the median follow-up was 35 (10-59) months, the number of patients with morphological recurrence in the treatment group was 30.4% (7/23) , which was significantly lower than that in the control group (50.2%, 24/46) (χ(2)=2.929, P=0.087) , although there was no statistically significant difference between the two groups. There was no significant difference on MRD-negative between the treatment and the control groups (43.5% vs 43.5%, χ(2)=1.045, P=0.307) . The 3-year leukemia-free survival was better in the treatment group [ (65.1±11.1) %] than that in the control group [ (50.0±7.4) %] (P=0.047) . The 3-year overall survival in the treatment and control groups were (78.1±10.2) % and (65.8±8.0) % (P=0.212) , respectively. Conclusion: The consolidation of chemotherapy combined with allogeneic NK cell infusion contributed to the further remission of patients with LMR AML and the reduction of long-term recurrence.

[Analysis of induction efficacy and prognostic factors in FLT3-ITD positive acute myeloid leukemia in the real world].

Objective: To investigate the efficacy and prognostic factors of induction therapy in FLT3-ITD(+) acute myeloid leukemia (AML) in the real world data. Methods: From January 2013 to December 2016, 114 de novo patients with FLT3-ITD(+)AML were enrolled in this study. Out of 114 cases, 75 were male, and 39 were female. The median age was 42 years old (ranged from 14 to 72 years old) . The chemotherapy regimens were used for induction therapy and all cases were followed up. The treatment response was evaluated by MICM and the comparison of the ratio were analyzed by chi-square test and the survival was estimated by Kaplan-Meier analysis and Cox proportional hazards model was used to identify independent prognostic factors. Results: There were 52 FLT3-ITD(+)AML patients with favorable prognosis genes (46 cases with NPM1, 5 cases with RUNX1-RUNX1T1, 1 case with CEBPA double mutation) and 62 patients with other types of FLT3-ITD(+)AML at diagnosis. All patients completed at least one cycle of induction therapy and the clinical curative effect was evaluated, complete remission (CR) rate was 50.0% (57/114) in one cycle and total CR rate was 72.5% (74/104) in two cycles. The CR rate of the FLT3-ITD(+) AML patients with favorable prognosis genes was 67.3% (35/52) in one cycle and 83.3% (40/48) in two cycles; for the other types FLT3-ITD(+)AML patients, the CR rate was 35.5% (22/62) in one cycle and 64.8% (35/54) in two cycles. There was a significant difference in CR rate between the FLT3-ITD(+)AML patients with and without favorable prognosis genes (P<0.05) . This indicates that the FLT3-ITD(+)AML patients with favorable prognosis gene had relatively good therapeutic effect. Among other types of FLT3-ITD(+)AML patients who did not achieve remission from one cycle of chemotherapy, 9 patients were given sorafenib plus chemotherapy and 6 cases (66.7%) achieved CR; 23 patients were given conventional chemotherapy and 7 cases (30.4%) achieved CR. There was a significant difference between sorafenib plus chemotherapy and conventional chemotherapy groups (χ(2)=4.47, P<0.05) and this indicates that sorafenib plus chemotherapy can significantly improve the CR rate of FLT3-ITD(+)AML patients. Comparing overall survival (OS) and disease free survival (DFS) , there was no significant difference between sorafenib plus chemotherapy and conventional chemotherapy groups (P values were 0.641 and 0.517, respectively) . Conclusion: The overall prognosis of FLT3-ITD(+)AML patients is poor, and the stratification therapeutic efficacy of FLT3-ITD(+)AML without favorable prognosis gene can be improved by sorafenib combined with chemotherapy.

[Efficacy and safety of decitabine in combination with G-CSF, low-dose cytarabine and aclarubicin in MDS-EB and AML-MRC].

Objective: To evaluate the clinical efficacy and safety of decitabine in combination with lower-dose CAG regimen (G-CSF, cytarabine and aclarubicin; D-CAG regimen) in the treatment of myelodysplastic syndromes with excess blasts (MDS-EB) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), compared to standard CAG regimen. Methods: A total of 42 patients with newly diagnosed MDS-EB and AML-MRC from May 2011 to March 2017 were included in the retrospective study. 21 cases were initially treated with G-CSF for priming, in combination with cytarabine of 10 mg/m(2) q12h for 14 days and aclarubicin of 20 mg/d for 4 days (CAG regimen) and the other 21 cases were initially treated with decitabine of 20 mg/m(2) for 5 days and lower-dose CAG regimen (cytarabine of 10 mg/m(2) q12h for 7 days, aclarubicin of 10 mg/d for 4 days, and G-CSF for priming (D-CAG regimen). After two cycles of induction chemotherapy, the patients who obtained complete remission(CR) received consolidation chemotherapy or hematopoietic stem cell transplantation (HSCT). Results: Among a total of 42 patients, the median age was 52.5 years (18-65 years) and 64.3% of them were male. Baseline characteristics of patients between D-CAG group and CAG group showed no significant differences. The CR for patients in D-CAG group was 81.0% (17/21), compared to 52.4% (11/21) in CAG group after 2 cycles of therapy (χ(2)=3.857, P=0.050). The overall response rate (ORR) for patients in D-CAG group and CAG group was 85.7% (18/21) and 76.2% (15/21) respectively, without significant difference (χ(2)=1.273, P=0.259). By December 2017, the median follow-up of D-CAG group and CAG group was 13(6-32) months and 15(2-36) months respectively. Finally, 10 patients in D-CAG group and 7 patients in CAG group received HSCT respectively. Except patients receiving HSCT, the median leukemia-free survival (LFS) time for patients in D-CAG group and CAG group was 18.0 (95%CI 6.6-29.4) months and 11.0 (95%CI 0-23.9) months respectively. Probabilities of 12 months LFS for D-CAG group and CAG group were (63.6±14.5)% and (50.0±13.4)% respectively, without difference (χ(2)=0.049, P=0.824). Except patients receiving HSCT, there were 2 deaths in D-CAG group and 7 deaths in CAG group respectively. The cumulative probabilities of 12 months OS for non-HSCT patients in D-CAG group and CAG group were (90.9±8.7)% and (61.5±13.5)% respectively, without significant difference (χ(2)=1.840, P=0.175). The incidences of side effects between D-CAG group and CAG group did not show significant differences (P=0.479), and the main side effects included cytopenias, pneumonia, infections of skin and soft tissues, neutropenic patients with fever, liver dysfunction. Conclusion: The decitabine in combination with lower-dose CAG regimen improved CR for patients with MDS-EB and AML-MRC, and was a promising choice.

[The 464th case: sudden convulsion and coma in a patient with acute leukemia].

A 46-year-old female patient was diagnosed as mixed phenotype acute leukemia with chief complaints of intermittent gingival swelling and bleeding for 1 week. The induction chemotherapy was not effective. During the second course chemotherapy, the patient had sudden convulsion and coma. She was transferred to the intensive care unit with worsened condition after transient improvement. Her final diagnosis was secondary adrenocortical insufficiency, adrenal crisis, intractable hyponatremia and cerebral edema.

[Clinical features and early treatment effects in intermediate risk and poor risk acute myeloid leukemia with EVI1 positive].

OBJECTIVE: To investigate the clinical biological characteristics of EVI1 positive acute myeloid leukemia (AML) and its effect on early chemotherapy. METHODS: The clinical and biological cha-racteristics of 33 AML patients with EVI1 positive were retrospectively analyzed in 361 AML patients who were diagnosed and treated in our institute from March 2015 to July 2016, and the clinical and biological features, and rates of the induced remission were compared between the intermediate risk and poor risk with EVI1 positive AML, moreover, the influential factors on complete remission (CR) were analyzed. The expression of EVI1/ABL was tested in 32 healthy donors to confirm the abnormal threshold of EVI1 expression. RESULTS: The definition of EVI1 positive was that the quantitative expression of EVI1/ABL was more than 8.0%. The 33 AML patients with EVI1 positive were found in 361 newly diagnosed AML patients, in which the female and male patients were 17 and 16 respectively, the median age was 45 (18-67) years, with a median follow-up of 6.6 (0.7-13.2) months. Intermediate karyotype was found in 17 patients(including 9 patients with normal karyotypes,1 patient with +8);unfavorable karyotype was found in 14 patients [including 7 patients with -7/7q-,4 patients with t (v;11q23),3 patients with inv(3)/t(3;3), and 2 patients without mitotic figures]. The rate of CR in the first induction chemotherapy was 42.4%, and the rate of total CR was 60.6%. According to the NCCN, 16 intermediate risk patients and poor risk patients were divided, without favorable risk patients. The rate of CR in the first induction chemotherapy were 68.8% and 17.6% (P=0.005) in the intermediate risk and poor risk respectively, that of total CR were 81.3% and 41.2%(P=0.032), and the rates of relapse were 7.7% and 14.3%.Univariable analysis revealed that unfavorable karyotype could affect the rate of CR in the first reduction chemotherapy and that of total CR (P=0.004, 0.029). The poor risk patients had higher mortality (41.2% vs. 6.3%, P=0.039) and lower overall survival (OS)(P=0.012). CONCLUSION: EVI1 may be not an independent prognostic factor for the AML patients considering the appea-rance in the intermediate and poor risk patients. It predicts poor outcome in the EVI1 positive AML patients who have unfavorable karyocytes, such as -7/7q-, t(v;11q23), and inv(3)/t(3;3), and also a low rate of both CR in the first induction chemotherapy and total CR. It also has a low rate of long-term survival and high mortality in the AML patients with EVI1 positive, who may benefit from allogeneic bone marrow transplantation as soon as possible.

[Efficacy and safety of Sorafenib as monotherapy to FLT3-ITD positive acute myeloid leukemia].

Objective: To explore the efficacy and safety of Sorafenib as monotherapy to FLT3 positive acute myeloid leukemia (AML). Methods: From April 2014 to December 2015, fourteen AML patients with FLT3 positive, 7 males and 7 females with a median age of 42 (range: 14-81) years old, were enrolled in this study. Of the 14 cases, 4 were de novo cases, 9 refractory cases and 1 relapsed case, including 78.6% patients with severe complications and 57.1% patients with KPS score less than 60 [the median KPS score was 45 (20-70) ]. The administration of Sorafenib was 400 mg twice daily and Sorafenib was continued if tolerated. The treatment response was evaluated by MICM and the data were analyzed by paired samples t test before and after Sorafenib treatment. Results: The peripheral blood WBC count [4.2 (0.9-11.8) ×109/L vs 39.6 (2.3-209.5) ×109/L, P<0.001 ], the percentage of peripheral blast cell [0.07 (0-0.54) vs 0.53 (0-0.94), P<0.001] and the percentage of bone marrow blast cell [0.266 (0.020-0.880) vs 0.604 (0.180-0.900), P=0.003] were significantly decreased after Sorafenib monotherapy compared with before. The overall response rate was 57.1% (8/14), including 5 cases (35.7%) with complete remission (CR). Of 4 de novo cases, 2 achieved CR, 1 with PR, 1 with NR; 3 of 10 refractory and relapsed patients achieved CR and 2 cases achieved PR, 5 cases NR. The median duration of achieving molecular remission (FLT3-ITD negative) after Sorafenib was 46(33-72) days, and the median progression free survival (PFS) was 53 (28-175) days. Conclusion: Sorafenib shows activity in FLT3-ITD mutation positive AML patients. Sorafenib monotherapy could be used as a treatment option for elderly patients or patients with severe complications, and refractory and relapsed patients with not suitable for intensive chemotherapy.

Antioxidative activity and protective effect of probiotics against high-fat diet-induced sperm damage in rats.

In this study, antioxidant capability and protective effect of probiotics on reproductive damage induced by diet oxidative stress were investigated. Thirty male Sprague-Dawley rats were randomly divided into three groups with 10 rats in each group. The control group consumed a normal standard diet (5% fat, w/w). The other two treatment groups were fed with a high-fat diet (20% fat, w/w), and a high-fat diet supplemented with 2% probiotics (w/w), respectively. At the end of the experimental period, that is, after 6 weeks, rats were killed. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), contents of nitric oxide (NO) free radical and malondialdehyde (MDA) in serum and sperm suspension were examined. Sperm parameters including sperm concentration, viability, motility and DNA integrity were analyzed. The results showed that high-fat diet could induce oxidative stress, shown as significant increases in lipid peroxidation, NO free radical, significant decrease in activities of SOD, GSH-Px, significant reduction in sperm concentration, viability and motility, and damage in sperm DNA (P < 0.05), compared with the control group. These alterations were significantly reversed in the probiotics-supplemented group and had no significant difference in antioxidant capability, lipid peroxidation and sperm parameters compared with the control group. The percentage of sperm with DNA damage was significantly lower than the high-fat diet group and still higher than the control group, which means that probiotics could attenuate sperm damage to some extent. The present results indicated that dietary probiotics had antioxidant activity and the protective effect against sperm damage induced by high-fat diet to some extent.

Occurrence of Grapevine Trunk Disease Caused by Botryosphaeria rhodina in China.

In the early summer of 2009, grapevine (Vitis vinifera), an important fruit crop in China, declined in most of the vineyards in Hunan, Hubei, and Zhejiang provinces. Characteristic symptoms of Botryosphaeria canker were apparent, including trunk cankers (visible in cross-section), leaf drop, shriveling and drying of fruit clusters, and berry rot (1). To identify the causal pathogen, we tested 126 samples by attempting to culture the pathogen from a small piece of tissue from the canker margin between the necrotic and apparently healthy tissue. Plant tissue was surface sterilized by placing it in 75% ethanol for 1 min and rinsed with sterilized water three times before culturing to potato dextrose agar (PDA) at 28°C. Five days later, the cultures were hyphal-tip purified and then single-spore isolates were used for identification. On the basis of colony characteristics in PDA, these colonies were identified as Botryosphaeria spp. (2). They were grayish white, becoming dark brown with age, and pycnidia were formed after incubation for approximately 9 days. Conidia measured 11 to 15 × 22 to 28 µm. A subset of isolates were used for rDNA ITS (internal transcribed spacer) sequence analysis with primers ITS1 and ITS4 (3). PCR products were separated by electrophoresis and bands were purified (Qiagen Plasmid Mini Kit; Qiagen, Valencia, CA) for sequencing (Sunbiotech Company, Beijing). BLAST searches of three ITS sequences (Accession Nos. GU226851, GU226853, and GU226856) had 100% identity to B. rhodina. EF1-α and ß-tubulin sequence analysis gave similar results. Koch's postulates were completed in the laboratory on grape shoots inoculated with two isolates of B. rhodina, originally isolated from plants in the field with symptoms of Botryosphaeria canker. Isolates were incubated on PDA at 25°C for 1 week. Inoculations were made on green shoots of V. vinifera cvs. Muscat Hamburg and Crimson Seedless. Five shoots per cultivar were inoculated per isolate by wounding with a 4-mm cork borer (2 mm deep), placing a colonized agar plug on the wound, and wrapping the wound with Parafilm. Controls were mock inoculated with an agar plug from sterile PDA. Inoculated shoots were incubated in the laboratory in the dark under moist conditions for 10 days at 25°C. Inoculated shoots had necrotic cankers after 10 days and B. rhodina was recovered from each canker margin. The results suggest that some grapevines in China with symptoms of Botryosphaeria canker were indeed infected by B. rhodina. To our knowledge, this is the first report of this pathogen on grapevine in China. References: (1) J. Luque et al. Mycologia 97:1111, 2005. (2) J. M. Niekerk et al. Mycologia 96:781, 2004. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Optically active dendrimers with a binaphthyl core and phenylene dendrons: light harvesting and enantioselective fluorescent sensing.

Optically active dendrimers containing a 1,1'-binaphthyl core and cross-conjugated phenylene dendrons were synthesized and characterized. The chiral optical properties of these phenylene-based dendrimers are different from the previously reported phenyleneethynylene-based dendrimers probably because of the increased steric interaction between the adjacent phenylene units. UV and fluorescence spectroscopic studies demonstrate that the energy harvested by the periphery of the dendrimers can be efficiently transferred to the more conjugated core, generating much enhanced fluorescence signal at higher generation. The fluorescence of these dendrimers can be quenched both efficiently and enantioselectively by chiral amino alcohols. The energy migration and light-harvesting effects of the dendrimers make the higher generation dendrimer more sensitive to fluorescent quenchers than the lower ones. Thus, the dendritic structure provides a signal amplification mechanism. These materials are potentially useful in the enantioselective recognition of chiral organic molecules.