Evaluation of Human Hepatocyte Drug Metabolism Carrying High-Risk or Protection-Associated Liver Disease Genetic Variants.

Metabolic-dysfunction-associated steatotic liver disease (MASLD), which affects 30 million people in the US and is anticipated to reach over 100 million by 2030, places a significant financial strain on the healthcare system. There is presently no FDA-approved treatment for MASLD despite its public health significance and financial burden. Understanding the connection between point mutations, liver enzymes, and MASLD is important for comprehending drug toxicity in healthy or diseased individuals. Multiple genetic variations have been linked to MASLD susceptibility through genome-wide association studies (GWAS), either increasing MASLD risk or protecting against it, such as PNPLA3 rs738409, MBOAT7 rs641738, GCKR rs780094, HSD17B13 rs72613567, and MTARC1 rs2642438. As the impact of genetic variants on the levels of drug-metabolizing cytochrome P450 (CYP) enzymes in human hepatocytes has not been thoroughly investigated, this study aims to describe the analysis of metabolic functions for selected phase I and phase II liver enzymes in human hepatocytes. For this purpose, fresh isolated primary hepatocytes were obtained from healthy liver donors (n = 126), and liquid chromatography-mass spectrometry (LC-MS) was performed. For the cohorts, participants were classified into minor homozygotes and nonminor homozygotes (major homozygotes + heterozygotes) for five gene polymorphisms. For phase I liver enzymes, we found a significant difference in the activity of CYP1A2 in human hepatocytes carrying MBOAT7 (p = 0.011) and of CYP2C8 in human hepatocytes carrying PNPLA3 (p = 0.004). It was also observed that the activity of CYP2C9 was significantly lower in human hepatocytes carrying HSD17B13 (p = 0.001) minor homozygous compared to nonminor homozygous. No significant difference in activity of CYP2E1, CYP2C8, CYP2D6, CYP2E1, CYP3A4, ECOD, FMO, MAO, AO, and CES2 and in any of the phase II liver enzymes between human hepatocytes carrying genetic variants for PNPLA3 rs738409, MBOAT7 rs641738, GCKR rs780094, HSD17B13 rs72613567, and MTARC1 rs2642438 were observed. These findings offer a preliminary assessment of the influence of genetic variations on drug-metabolizing cytochrome P450 (CYP) enzymes in healthy human hepatocytes, which may be useful for future drug discovery investigations.

From a Single Cell to a Whole Human Liver: Disease Modeling and Transplantation.

Although the underlying cause may vary across countries and demographic groups, liver disease is a major cause of morbidity and mortality globally. Orthotopic liver transplantation is the only definitive treatment for liver failure but is limited by the lack of donor livers. The development of drugs that prevent the progression of liver disease and the generation of alternative liver constructs for transplantation could help alleviate the burden of liver disease. Bioengineered livers containing human induced pluripotent stem cell (iPSC)-derived liver cells are being utilized to study liver disease and to identify and test potential therapeutics. Moreover, bioengineered livers containing pig hepatocytes and endothelial cells have been shown to function and survive after transplantation into pig models of liver failure, providing preclinical evidence toward future clinical applications. Finally, bioengineered livers containing human iPSC-derived liver cells have been shown to function and survive after transplantation in rodents but require considerable optimization and testing prior to clinical use. In conclusion, bioengineered livers have emerged as a suitable tool for modeling liver diseases and as a promising alternative graft for clinical transplantation. The integration of novel technologies and techniques for the assembly and analysis of bioengineered livers will undoubtedly expand future applications in basic research and clinical transplantation.

Study for the Diagnostic Screening of Paroxysmal Nocturnal Hemoglobinuria in Older Patients with Unexplained Anemia and/or Cytopenia.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematopoietic stem cell disease that may lead to weakness and death of patients, if unrecognized and untreated. Although consensus guidelines were reviewed recently for the diagnostic screening of PNH with multi-parameter flow cytometry (FCM), until now, no study has investigated the efficiency of such clinical indications in older patients. METHODS: Overall, 20 centers participated in the study and a total of 1,689 patients were included, 313 of whom were at geriatric age and 1,376 were aged 18 - 64 years. We evaluated the efficiency of consensus clinical indications for PNH testing using FCM in peripheral blood samples and compared the results of older patients and patients aged 18 - 64 years. RESULTS: PNH clones were detected positive in 7/313 (2.2%) of the older patients. Five (74.4%) of the patients with PNH clones had aplastic anemia, 1 had unexplained cytopenia, and 1 patient had myelodysplastic syndrome (MDS) with refractory anemia. PNH clones were not detected in any older patients who were screened for unexplained thrombosis, Coombs (-) hemolytic anemia, hemoglobinuria, and others (e.g., elevated lactate dehydrogenase (LDH), splenomegaly). We detected PNH clones in 55/1376 (4%) samples of the patients aged under 65 years. Forty-two (76.4%) patients with PNH clones had aplastic anemia, 2 patients had Coombs (-) hemolytic anemia, 3 patients had unexplained cytopenia, 1 patient had MDS with refractory anemia, 1 patient had hemoglobinuria, and 6 (10.9%) had others (e.g., elevated LDH, splenomegaly). PNH clones were not detected in any patients who were screened for unexplained thrombosis. There was no statistical difference between the geriatric population and patients aged 18 - 64 years in terms of clinical indications for PNH screening with FCM (p = 0.49). CONCLUSIONS: Our results showed that the current clinical indications for PNH screening with FCM were also efficient in older patients. We suggest that older patients with unexplained anemia, myelodysplastic syndrome with refractory anemia, and unexplained cytopenia should be screened for PNH with FCM to identify patients who would benefit from treatment.

Evaluating compliance with the care standard of proactively assessing bone health in patients with diabetes: a pilot audit of practice across Asia by the Asia Pacific Consortium on Osteoporosis (APCO).

This pilot audit explored how bone health is assessed patients with diabetes in diverse centres across Asia. Only 343 of 1092 (31%) audited patients had a bone health assessment, 27% of whom were diagnosed with osteoporosis. Quality improvement strategies are needed to address gaps in patient care in this area. PURPOSE: The Asia Pacific Consortium on Osteoporosis (APCO) Framework outlines clinical standards for assessing and managing osteoporosis. A pilot audit evaluated adherence to clinical standard 4, which states that bone health should be assessed in patients with conditions associated with bone loss and/or increased fracture risk; this report summarises the audit findings in patients with diabetes. A secondary aim was to assess the practicality and real-world use of the APCO bone health audit tool kit. METHODS: Eight centres across Asia participated in the pilot audit, selecting diabetes as the target group. Participants reviewed their practice records for at least 20 consecutively treated patients with the target condition. Questions covered routine investigations, bone health assessment, osteoporosis diagnosis, and patient referral pathways. Data were summarised descriptively. RESULTS: The participants represented public hospitals, university medical centres, and private clinics from India, Malaysia, Pakistan, Singapore, Taiwan, and Vietnam that see an estimated total of 95,000 patients with diabetes per year. Overall, only 343 of 1092 audited patients (31%) had a bone health assessment. Osteoporosis was subsequently diagnosed in 92 of 343 (27%) patients. CONCLUSION: Bone health was not assessed in most patients with diabetes. The results provide insight into current practices across diverse Asian centres and demonstrate the practical value of the audit tool kit. Participant feedback has been used to improve the tool kit. Results of this pilot audit are being used in the respective centres to inform quality improvement projects needed to overcome the gap in patient care.

Polymorphisms Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease Influence the Progression of End-Stage Liver Disease.

BACKGROUND AND AIMS: Chronic liver injury that results in cirrhosis and end-stage liver disease (ESLD) causes more than 1 million deaths annually worldwide. Although the impact of genetic factors on the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-related liver disease (ALD) has been previously studied, their contribution to the development of ESLD remains largely unexplored. METHODS: We genotyped 6 MASLD-associated polymorphisms in healthy (n = 123), metabolic dysfunction-associated steatohepatitis (MASH) (n = 145), MASLD-associated ESLD (n = 72), and ALD-associated ESLD (n = 57) cohorts and performed multinomial logistic regression to determine the combined contribution of genetic, demographic, and clinical factors to the progression of ESLD. RESULTS: Distinct sets of factors are associated with the progression to ESLD. The PNPLA3 rs738409:G and TM6SF2 rs58542926:T alleles, body mass index (BMI), age, and female sex were positively associated with progression from a healthy state to MASH. The PNPLA3 rs738409:G allele, age, male sex, and having type 2 diabetes mellitus were positively associated, while BMI was negatively associated with progression from MASH to MASLD-associated ESLD. The PNPLA3 rs738409:G and GCKR rs780094:T alleles, age, and male sex were positively associated, while BMI was negatively associated with progression from a healthy state to ALD-associated ESLD. The findings indicate that the PNPLA3 rs738409:G allele increases susceptibility to ESLD regardless of etiology, the TM6SF2 rs58542926:T allele increases susceptibility to MASH, and the GCKR rs780094:T allele increases susceptibility to ALD-associated ESLD. CONCLUSION: The PNPLA3, TM6SF2, and GCKR minor alleles influence the progression of MASLD-associated or ALD-associated ESLD. Genotyping for these variants in MASLD and ALD patients can enhance risk assessment, prompting early interventions to prevent ESLD.

Transmembrane channel activity in human hepatocytes and cholangiocytes derived from induced pluripotent stem cells.

The initial creation of human-induced pluripotent stem cells (iPSCs) set the foundation for the future of regenerative medicine. Human iPSCs can be differentiated into a variety of cell types in order to study normal and pathological molecular mechanisms. Currently, there are well-defined protocols for the differentiation, characterization, and establishment of functionality in human iPSC-derived hepatocytes (iHep) and iPSC-derived cholangiocytes (iCho). Electrophysiological study on chloride ion efflux channel activity in iHep and iCho cells has not been previously reported. We generated iHep and iCho cells and characterized them based on hepatocyte-specific and cholangiocyte-specific markers. The relevant transmembrane channels were selected: cystic fibrosis transmembrane conductance regulator, leucine rich repeat-containing 8 subunit A, and transmembrane member 16 subunit A. To measure the activity in these channels, we used whole-cell patch-clamp techniques with a standard intracellular and extracellular solution. Our iHep and iCho cells demonstrated definitive activity in the selected transmembrane channels, and this approach may become an important tool for investigating human liver biology of cholestatic diseases.

Human Hepatocytes Isolated from Explanted Livers: A Powerful Tool to Understand End-stage Liver Disease and Drug Screening.

The use of primary human hepatocytes has been hampered by limited availability of adequate numbers of fresh and viable cells due to the ongoing shortage of liver donors. Thus, there is no surplus of healthy organs from which freshly isolated cells can be prepared when needed. However, primary hepatocytes can be successfully isolated from explanted liver specimens obtained from patients receiving orthotopic liver transplantation for decompensated liver cirrhosis or for metabolic liver disease without end-stage liver disease and are a valuable resource for the pharmaceutical industry research. This review focuses on the isolation, characterization and cryopreservation of hepatocytes derived from therapeutically resected livers with various hepatic diseases.

Therapeutic Potential of HNF4α in End-stage Liver Disease.

The prevalence of end-stage liver disease (ESLD) in the US is increasing at an alarming rate. It can be caused by several factors; however, one of the most common routes begins with nonalcoholic fatty liver disease (NAFLD). ESLD is diagnosed by the presence of irreversible damage to the liver. Currently, the only definitive treatment for ESLD is orthotopic liver transplantation (OLT). Nevertheless, OLT is limited due to a shortage of donor livers. Several promising alternative treatment options are under investigation. Researchers have focused on the effect of liver-enriched transcription factors (LETFs) on disease progression. Specifically, hepatocyte nuclear factor 4-alpha (HNF4α) has been reported to reset the liver transcription network and possibly play a role in the regression of fibrosis and cirrhosis. In this review, we describe the function of HNF4α, along with its regulation at various levels. In addition, we summarize the role of HNF4α in ESLD and its potential as a therapeutic target in the treatment of ESLD.

Is HSD17B13 Genetic Variant a Protector for Liver Dysfunction? Future Perspective as a Potential Therapeutic Target.

As diet and lifestyle have changed, fatty liver disease (FLD) has become more and more prevalent. Many genetic risk factors, such as variants of PNPLA3, TM6SF2, GCKR, and MBOAT7, have previously been uncovered via genome wide association studies (GWAS) to be associated with FLD. In 2018, a genetic variant (rs72613567, T > TA) of hydroxysteroid 17-ß dehydrogenase family 13 (HSD17B13) was first associated with a lower risk of developing alcoholic liver disease and non-alcoholic fatty liver disease (NAFLD) in minor allele carriers. Other HSD17B13 variants were also later linked with either lower inflammation scores among NAFLD patients or protection against NAFLD (rs6834314, A > G and rs9992651, G > A) respectively. HSD17B13 is a lipid droplet-associated protein, but its function is still ambiguous. Compared to the other genetic variants that increase risk for FLD, HSD17B13 variants serve a protective role, making this gene a potential therapeutic target. However, the mechanism by which these variants reduce the risk of developing FLD is still unclear. Because studies in cell lines and mouse models have produced conflicting results, human liver tissue modeling using induced pluripotent stem cells may be the best way to move forward and solve this mystery.

Effects of adding magnesium to bupivacaine and fentanyl for spinal anesthesia in knee arthroscopy.

PURPOSE: The aim of the study was to investigate the effects of adding intrathecal magnesium sulfate 50 mg to low-dose bupivacaine-fentanyl on the spread, duration, regression of spinal block, and postoperative analgesia in patients undergoing knee arthroscopy. METHODS: This study was designed in a prospective, randomized, and double-blinded manner. Sixty American Society of Anesthesiologists (ASA) physical status I or II patients were randomly allocated to receive 50 mg magnesium sulfate (3 ml) or 3 ml of preservative-free 0.9% NaCl following 6 mg bupivacaine 0.5% plus 10 microg fentanyl intrathecally. Date were collected regarding the highest level of dermatomal sensory blockade, the time to reach this level from the time of injection of the spinal anesthetic, Bromage scale of motor blockade at the time of reaching maximum sensory level, time for regression of two segments in the maximum block height, time to L(2) regression, time to ambulation, and postoperative analgesic consumption. RESULTS: The addition of intrathecal magnesium (50 mg) to spinal anesthesia prolonged the time for regression of two segments in the maximum block height and time to L(2) regression, but did not affect maximum sensory level or the time to reach the highest level of sensory block. Even though the mean times to complete recovery of motor function were similar in the two groups, time to ambulation was significantly longer in the magnesium group than in the saline group. Total analgesic consumption in the first 24 h was not decreased significantly with the addition of magnesium to spinal anesthesia, but the time to first analgesic requirement was prolonged significantly. CONCLUSION: Even though the time to first analgesic requirement was prolonged significantly by magnesium, the addition of intrathecal magnesium sulfate to spinal anesthesia is not desirable in patients undergoing knee arthroscopy due to the prolonged time to ambulation and the lack of effect of magnesium on postoperative analgesic consumption.

Effects of betamethasone on fetoplacental and maternal hemodynamics in preterm pregnancies.

OBJECTIVE: To evaluate the possible effects of prenatal steroid administration on Doppler parameters of the umbilical artery, uterine artery, middle cerebral artery, and ductus venosus, the cerebroplacental ratio, and the amniotic fluid index in preterm fetuses. METHODS: The present prospective observational study was performed at the Perinatology Department of Trakya University, Edirne, Turkey, between June 1, 2015, and September 1, 2016. It included patients with healthy singleton pregnancies who had received betamethasone at 24-34 weeks of pregnancy. Doppler parameters were measured before (0 hours) and 24, 48, and 72 hours after the administration of betamethasone (two intramuscular doses of 12 mg each, administered 24 hours apart). RESULTS: There were 68 patients included. Pairwise comparisons demonstrated that, at 72 hours after betamethasone administration, the umbilical artery resistance index (P=0.038), the middle cerebral artery systolic/diastolic velocity ratio (P=0.007), and the amniotic fluid index (P=0.017) were reduced, whereas the end-diastolic velocity of the middle cerebral artery was increased (P=0.012), compared with baseline values. CONCLUSION: Betamethasone had favorable effects on fetal cerebral circulation, with increased end-diastolic velocity in the middle cerebral artery; this could represent a positive effect on cerebral blood circulation and decreased flow resistance in the umbilical artery.

Drug utilization and teratogenicity risk categories during pregnancy.

A limited number of studies have investigated in detail the use of drugs during pregnancy. Researchers in the present study investigated the details of drug utilization in pregnant women during the month before pregnancy, at the time that they became aware of the pregnancy, and during the first trimester. Face-to-face interviews were conducted with 359 pregnant women who were admitted to the fetal medicine unit at a university hospital for diagnosis and follow-up. A questionnaire was used to document sociodemographic characteristics and details of drug use. Drugs were categorized according to the US Food and Drug Administration fetal risk classification. Mean maternal age was 29.9+/-5.1 y, and mean gestational age was 19.6+/-9.5 wk. Many of the pregnant women studied (46.6%) were university graduates, and most (61.9%) had a relatively high annual income. Mean gestational age when participants first learned of their pregnancy was 39.8+/-16.4 d. One hundred seventeen participants (32.6%) used drugs during the month before conception, 54 (15%) at the time when they learned of their pregnancy, 180 (50.1%) at the time of the interview, and 289 (80.5%) during the first trimester. The percentages of drugs in categories D and X used by these subjects were 14%, 13.5%, 2.9%, and 5.9%, respectively. Most of the drugs were hormones. The total rate of drug utilization was not high before and during the first trimester of pregnancy. A considerable number of women were using drugs from the D and X categories; however, these numbers decreased significantly when women learned of their pregnancies. Intake of folic acid, vitamins, and iron was very low during the preconception period and was not high enough during the first trimester; this suggests that particular attention should be paid to the use of beneficial "safe" drugs during the preconception and early pregnancy periods.

Normal standards of fetal behavior assessed by four-dimensional sonography.

OBJECTIVE: In this prospective randomized study, fetal behavior was investigated in order to determine the standard parameters of fetal movements and facial expressions in all three trimesters of normal pregnancy. METHODS: Sixty-three pregnant women with singleton pregnancies in all trimesters were included in the investigation. Four-dimensional (4D) ultrasound was performed for each patient over a 30-minute period. Variables of maternal and fetal characteristics including gestational age, eight fetal movement patterns in the first trimester, and sixteen parameters of fetal movement and fetal facial expression patterns in the second and third trimesters were recorded for the construction of fetal neurological charts. RESULTS: In the first trimester, a tendency towards an increased frequency of fetal movement patterns with increasing gestational age was noticed. Only the startle movement pattern seemed to occur stagnantly during the first trimester (p > 0.05). At the beginning of the second trimester, the frequency of fetal movement patterns tended to increase. During the second and third trimester, multiple regression and polynomial regression revealed statistically significant changes in tongue expulsion (p < 0.05), smiling (p < 0.05), grimacing (p < 0.05), swallowing (p < 0.05), eye blinking (p < 0.01), head movements, and all hand to body contact movements (p < 0.01), except for head anteflexion (p > 0.05). There were no statistically significant changes during the second and third trimesters in mouthing, yawning, and sucking (p > 0.05). At the middle of the third trimester, the fetuses displayed decreasing or stagnant incidence of fetal facial expressions except for eye blinking, which showed increased frequency with increasing gestational age. A statistically significant correlation was found between all head movements and hand to body contact patterns during the second and third trimesters except for head anteflexion (r = -0.231; p > 0.05). CONCLUSIONS: The full range of quantitative fetal facial expressions and fetal movement patterns can be assessed successfully by 4D sonography. It is important to be able to assess normal fetal behavior throughout gestation to identify abnormal behavior before birth.

Spontaneous perforation of pyometra.

Pyometra is the accumulation of purulent material in the uterine cavity. Its reported incidence is 0.01-0.5% in gynecologic patients; however, as far as elderly patients are concerned, its incidence is 13.6% [3]. The most common cause of pyometra is malignant diseases of genital tract and the consequences of their treatment (radiotherapy). Other causes are benign tumors like leiomyoma, endometrial polyps, senile cervicitis, cervical occlusion after surgery, puerperal infections, and congenital cervical anomalies. Spontaneous rupture of the uterus is an extremely rare complication of pyometra. To our knowledge, only 21 cases of spontaneous perforation of pyometra have been reported in English literature since 1980. This paper reports an additional case of spontaneous uterine rupture.

Intra- and interobserver agreement on cervical volume and flow indices during pregnancy using transvaginal 3-dimensional ultrasonography and Doppler angiography.

OBJECTIVES: To assess intra- and interobserver agreement in cervical volume and flow indices measurements. METHOD: We prospectively examined 126 patients by two seperate observers using transvaginal 3D gray-scale and power Doppler ultrasound. The two acquired volume datasets were analyzed using the VOCAL imaging program for assessing cervical volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI). Reproducibility of volume and vascularity measurement was assessed by calculating intraclass (intra-CC) and interclass (inter-CC) correlation coefficients (ICCs). RESULTS: Both intraobserver and interobserver cervical volume measurements were in perfect agreement with intra-CC values of 0.95, 0.96 for both examiners and with an inter-CC value of 0.95. Intraobserver agreement for VI, FI and VFI measurements were as good as the interobserver agreement for VI, and VFI measurements were adequate but less for FI measurements (inter-CC 0.67). Overall, volumetric data were more reliably acquirable than power Doppler measurements. CONCLUSIONS: 3D ultrasound gray-scale and power Doppler measurement of cervical volume and vascularization have acceptable intra- and interobserver variations and thus may be used in clinical research of cervical physiology and pathophysiology during pregnancy.

Predictive power of maternal serum and amniotic fluid CRP and PAPP-A concentrations at the time of genetic amniocentesis for the preterm delivery.

OBJECTIVE: To investigate whether maternal serum and amniotic fluid CRP and PAPP-A concentrations at the time of genetic amniocentesis are markers of preterm delivery. STUDY DESIGN: One hundred and forty-one pregnant women were included in this prospective study. Amniotic fluid and maternal serum CRP and PAPP-A concentrations were determined by using commercially available kits. Receiver-operating characteristic (ROC) analysis was performed to determine the efficacy of maternal serum and amniotic fluid CRP and PAPP-A levels in predicting women with preterm delivery. RESULTS: The prevalence of spontaneous preterm delivery before 37 weeks of gestation was 9.9%. ROC analysis revealed that amniotic fluid CRP level was the only parameter, which had a significant power in the prediction of preterm delivery. The optimum cut-off level was 0.65 mg/L. The sensitivity and specificity were 92.9% and 78.7%, respectively. CONCLUSION: The amniotic fluid CRP level has a high sensitivity and specificity in the prediction of preterm delivery and this may be helpful in predicting preterm delivery during genetic amniocentesis.

Chromatography of alkaloids on titanium arsenate papers and quantitative separation of some alkaloids from nicotine on titanium arsenate columns.

Columns and papers of titanium arsenate have been utilized for chromatographic studies of several alkaloids in aqueous and mixed solvent systems. The results have been compared with those obtained with plain papers. A number of separations have been achieved on papers impregnated with titanium arsenate. Distribution coefficients of these alkaloids have been determined. A number of alkaloids have been separated quantitatively from nicotine on titanium arsenate columns.

Organic and inorganic ion-exchange beads as indicators in redox and precipitation titrations.

Resin beads in the Fe(III) or p-dimethylaminobenzylidene-rhodanine form are used as indicators in precipitation titrations with K(3)Fe(CN)(6), and Ag(+). Resin beads with dipheny lamine adsorbed on them can be used as indicators in cerimetric titrations. They have some advantages over conventional indicators.

Comparative study of titanium(IV)-based exchangers in aqueous and mixed solvent systems.

The antimonate, arsenate, tungstate, molybdate and selenite of titanium have been synthesized. Their composition and chemical and thermal stability have been determined. Effects of pH and temperature on ion-exchange capacity have been studied. Titanium antimonate was found to be the most stable. The utility of these ion-exchangers for analytical separations was examined by determining the distribution coefficients for 26 metal ions in some aqueous, non-aqueous and mixed solvent systems. Quantitative separations of HgCd, PbCu and PbZn have been achieved on titanium tungstate columns, and LaBa mixtures have been separated on a titanium arsenate column.

Acetylcholine: a possible neurotransmitter in Setaria cervi.

The total and free acetylcholine (Ach) and cholinesterase (CHE) content of adult Setaria cervi were estimated. The Ach was estimated by bioassay on rectus abdominis muscle of frog and the CHE by measuring the drop in pH following incubation of worm homogenate with Ach chloride. The free and total Ach contents (4.0 +/- 0.57 and 6.0 +/- 0.48 microgram/g wet weight of worms respectively) were as high as found in mammalian brain cortex. The cholinesterase activity was found to be 5.57 +/- 0.6 units/g wet weight of worms. It is possible that there may exist a well developed system responsible for the synthesis, storage, release and destruction of Ach and that Ach may be acting as an excitatory neurohormone in S. cervi.