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Post-transcriptional modifications affect tRNA biology and are closely associated with human diseases. However, progress on the functional analysis of tRNA modifications in metazoans has been slow because of the difficulty in identifying modifying enzymes. For example, the biogenesis and function of the prevalent N2-methylguanosine (m2G) at the sixth position of tRNAs in eukaryotes has long remained enigmatic. Herein, using a reverse genetics approach coupled with RNA-mass spectrometry, we identified that THUMP domain-containing protein 3 (THUMPD3) is responsible for tRNA: m2G6 formation in human cells. However, THUMPD3 alone could not modify tRNAs. Instead, multifunctional methyltransferase subunit TRM112-like protein (TRMT112) interacts with THUMPD3 to activate its methyltransferase activity. In the in vitro enzymatic assay system, THUMPD3–TRMT112 could methylate all the 26 tested G6-containing human cytoplasmic tRNAs by recognizing the characteristic 3′-CCA of mature tRNAs. We also showed that m2G7 of tRNATrp was introduced by THUMPD3–TRMT112. Furthermore, THUMPD3 is widely expressed in mouse tissues, with an extremely high level in the testis. THUMPD3-knockout cells exhibited impaired global protein synthesis and reduced growth. Our data highlight the significance of the tRNA: m2G6/7 modification and pave a way for further studies of the role of m2G in sperm tRNA derived fragments.

BACKGROUND: The concordance between mutations detected from plasma and tissue is critical for treatment choices of patients with advanced lung adenocarcinoma. METHODS: We prospectively analyzed the association of the serum tumor markers with the concordance between blood and tissue genomic profiles from 185 patients with advanced lung adenocarcinoma. The concordance was defined according to 3 criteria. Class 1 included all targetable driver mutations in 8 genes; class 2 included class 1 mutations plus mutations in KRAS, STK11, and TP53; class 3 included class 2 mutations plus tumor mutation burden (TMB) status. RESULTS: Collectively, 150 out of 185 patients had mutations in both tissue and plasma samples, while one patient was mutation-negative for both, resulting a concordance of 81.6%. The concordance rate for class 1 mutations was 80%, and 65% and 69% for class 2 and class 3, respectively. Carbohydrate antigen 19-9 (CA19-9) or cytokeratin 19 (CYFRA21-1) levels higher than the normal upper limit predicted the concordance of tissue and blood results in class 1 (P=0.005, P=0.011), class 2 (P=0.011, P0.99, P>0.99). When the sum score for 4 serum tumor markers was greater than 35, both class 1, class 2, and class 3 reached a predictive threshold of 90%. CONCLUSIONS: Serum tumor markers can be used as easy and practical clinical predictors of concordance in mutation profiles between blood and tissue samples from patients with advanced lung adenocarcinoma.

The modulation of the electronic structure is the effective access to achieve highly active electrocatalysts for the hydrogen evolution reaction (HER). Transition-metal phosphide-based heterostructures are very promising in enhancing HER performance but the facile fabrication and an in-depth study of the catalytic mechanisms still remain a challenge. In this work, the catalytically inactive n-type CeO

Chemical modifications expand the composition of RNA molecules from four standard nucleosides to over 160 modified nucleosides, which greatly increase the complexity and utility of RNAs. Transfer RNAs (tRNAs) are the most heavily modified cellular RNA molecules and contain the largest variety of modifications. Modification of tRNAs is pivotal for protein synthesis and also precisely regulates the noncanonical functions of tRNAs. Defects in tRNA modifications lead to numerous human diseases. Up to now, more than 100 types of modifications have been found in tRNAs. Intriguingly, some modifications occur widely on all tRNAs, while others only occur on a subgroup of tRNAs or even only a specific tRNA. The modification frequency of each tRNA is approximately 7% to 25%, with 5-20 modification sites present on each tRNA. The occurrence and modulation of tRNA modifications are specifically noticeable as plenty of interplays among different sites and modifications have been discovered. In particular, tRNA modifications are responsive to environmental changes, indicating their dynamic and highly organized nature. In this review, we summarized the known occurrence order, cross-talk, and cooperativity of tRNA modifications.

The design and fabrication of highly active, robust and cost-efficient electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great significance towards overall water splitting, but remains challenging as well. Herein, we report, for the first time, heterostructural Co/CeO2/Co2P/CoP@NC dodecahedrons as bifunctional electrocatalyst, in which abundant interfaces are formed between different components. Typical ZIF-67 (ZIF = zeolitic imidazolate framework) dodecahedrons with pre-inserted CeO2 nanowires were selected as precursors to synthesize Co/CeO2/Co2P/CoP@NC via a direct carbonization process followed by phosphidation, simultaneously generating the strong coupled heterojunction interfaces through interactions between CeO2 and CoxP species. Abundant porous structure leads to the exposure of more active sites and the carbon encapsulation of nanodomains sustains the high robustness and conductivity and the synergistic effect between the multi-components heterostructure. Benefiting from the above collective advantages, the Co/CeO2/Co2P/CoP@NC electrocatalysts exhibit small overpotentials of 307 and 195 mV to derive 10 mA cm−2 for OER and HER, respectively. Furthermore, an alkaline electrolyzer assembled by using Co/CeO2/Co2P/CoP@NC as both cathode and anode can achieve a current density of 10 mA cm−2 at a low voltage of 1.76 V and work continuously for over 15 h. This work would provide a rational protocol for fabrication multi-phase interface enriched electrocatalysts toward highly efficient energy conversion.

Emerging evidence revealed the critical role of systematic inflammation in pancreatic ductal adenocarcinoma (PDAC). In the present study, we reviewed the records of 279 patients with advanced PDAC. Among them, 147 cases were used as the training cohort and another 132 as the validation cohort. In the training cohort, distant metastasis, carbohydrate antigen 19-9 (CA19-9), Glasgow prognostic score (GPS), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR) were independent prognostic factors in Cox regression. A nomogram based on these factors was generated to predict median survival time and survival probabilities at 6, 12, and 18 months. The nomogram showed a better discriminatory ability than the American Joint Committee on Cancer (AJCC) TNM staging (C-index: 0.727 vs. 0.610). In the validation cohort, a nomogram composed of the same variables also showed a high discriminatory ability (C-index: 0.784). In the low-risk group with a nomogram total point (NTP) value of more than 175, patients receiving combination therapy showed better prognosis than those receiving monotherapy (P=0.015). In conclusion, the nomogram based on inflammatory biomarkers can serve as useful prognostic tool for advanced PDAC. In addition, patients with high NTP can greater benefit from combination chemotherapy than monotherapy.

Urinary crystals in normal and kidney stone patients often have varying sizes; the interaction between renal epithelial cells and COD crystals generated in the tubular fluid could play an initiating role in the pathophysiology of calcium oxalate nephrolithiasis. This study aims to compare the cytotoxicity of micro/nano-calcium oxalate dihydrate (COD) crystals (50 nm, 100 nm, 600 nm, 3 μm, and 10 μm) toward African green monkey renal epithelial (Vero) cells to reveal the mechanism of kidney stone formation at the molecular and cellular levels. Methods: Vero cells were exposed to COD crystals of varying sizes at a concentration of 200 μg mL−1 for 6 h. The effects of COD crystals on Vero cell viability, apoptosis rate, and cellular biochemical parameters [lactate dehydrogenase (LDH), superoxide dismutase (SOD), reactive oxygen species (ROS), hyaluronic acid (HA), osteopontin (OPN), and mitochondrial membrane potential (Δψm)] were determined using biochemical and morphological analyses. Results: Vero cell viability and apoptotic rate were closely associated with the size of COD crystals; lower cell viability and higher apoptosis rate were observed in cells exposed to smaller COD crystal size. The expression of SOD, ROS, HA and OPN also changed in a size-dependent manner after exposure to the five different sizes of COD crystals. The area ratio of the (100) face with a high density of Ca2+ ions to the total surface area was also found to influence the severity of cell injury. Cell injury induced by COD crystals was mainly caused by excessive expression of intracellular ROS and reduction of free-radical scavenger SOD. Moreover, binding of large crystals on the cell membrane surface takes more time to cause cell injury than internalized small-sized crystals. The cell death rate was found to be positively correlated with the amount of internalized COD crystals. Conclusions: although the COD toxicity is often disregarded, the size-dependent cytotoxicity of COD crystals toward Vero cells is demonstrated in this study.

Highly-efficient electrocatalysts for oxygen evolution reaction, especially for metal nanoparticles supported on layered double hydroxides (LDHs) are very desirable and highly challenge able in modern water splitting and metal air batteries. Herein, this work applies a novel and simple spontaneous redox reaction to fabricate a heterogeneous structure by depositing silver nanoparticles on MoO2-4 intercalating α-Co(OH)2 support in a quite quick manner (5 min). The as-constructed heterostructural interface endows the hybrid α-Co(OH)2/Ag with electronic interaction between Ag and α-Co(OH)2, modulated electronic structure, and synergistic effect. Furthermore, the spontaneously engineering interface also promotes the water adsorption and the valence state regulation and enhances the intrinsic activity of the catalytically active site. Benefitting from the above collective merits, the optimal heterostructural electrocatalyst (α-Co(OH)2/Ag-0.01) can drive a current density of 10 mA cm−2 at the overpotential of only 270 mV, outperforming the bare α-Co(OH)2 and even commercial benchmark RuO2. This work opens up a new avenue towards advanced OER electrocatalysts by cheap metal nanoparticles engaged interface engineering, also showing significant potential for other energy-related electrocatalysis.

The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sulfuric acid solutions were measured at temperatures ranging from 278.15 to 338.15 K by using a dynamic method. The concentration of sulfuric acid solution ranged from 0 to 80wt%,. The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate increased with temperature, and both of them were the lowest at 70wt%, of sulfuric acid solution(w 3 0 =0.70)while the highest in pure water. The solubility data were correlated by the modified Apelblat equation. Based on the solubility difference between 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate, a new technique in which sodium sulfate was used to replace sodium sulfite in the neutralization reaction was developed. The suitable mole ratio of H2O to Na2SO4 in the neutralization reaction was 80:1, and that of 2-naphthalenesulfonic acid monohydrate to Na2SO4 was 3.2:1. The material balance under the suitable mole ratios was given and discussed.

Background: The clotting system abnormalities are the common complication in cancer patients. The aim of this retrospective study was to evaluate the coagulation state, clinical features, and treatment in cancer patients by routine tests. Methods: A total of 2328 patients with different types of cancer were classified as the positive group (n = 1419, including 53 patients with thrombosis) and the negative group (n = 909) based on D-dimer (DD) value. Of the 2328 cases, 354 were admitted for chemotherapy. Hemostasis test and complete blood count (CBC) were performed during treatment or following-up. Results: This study showed that the hypercoagulable state was affected not only by clinical staging (P < 0.0001) but also by metastasis site (P < 0.0001 for bone vs. lung). Compared to negative DD group, the higher fibrinogen level, the extended activated partial thromboplastin time, and prothrombin time interacted markedly with disease clinical stage (P < 0.05) in the positive group. Between positive DD groups with and without thrombus, the significantly statistic difference in white blood cell (WBC) and DD (P < 0.05) rather than in red blood cell (RBC) and platelet count was observed. However, the higher DD level was not correlated with WBC, RBC, and platelet count in the positive DD group. Furthermore, the hypercoagulable plasma profile in cancer patients was moderated 2–3 weeks after chemotherapy (P < 0.05 for first six cycles). Conclusions: The routine hemostatic parameters and CBC are valuable to assessment for thrombosis and chemotherapy even for disease prognosis.

To separate a salt mixture (mainly consisting of Na2CO3 and Na2SO4) which is formed from the 4,4′-diaminostilbene-2,2′-disulfonic acid wastewater treatment, the solubility data of Na2CO3 and NaHCO3 in Na2SO4–water solvent mixtures were measured using a dynamic method over the 275–335 K temperature range. The solute-free mass fraction of Na2SO4 in the solvent mixtures extended from 0 to 0.25. The solubility of Na2CO3 and NaHCO3 in Na2SO4–water solvent mixtures decreased with addition of Na2SO4. With rising temperature, the solubility of NaHCO3 increased while the solubility of Na2CO3 increased at first and then decreased after transition points. The experimental data were correlated with the electrolyte nonrandom two-liquid model. The root-mean-square deviations of solubility temperature varied from 0.35 to 1.50 K. Based on the solubility data of this work, a new strategy for separating the Na2CO3 and Na2SO4 mixture was proposed theoretically.

The solubility of 4-chloro-2,5-dimethoxynitrobenzene (CDMB) and 4-chloro-2,5-dimethoxyaniline (CDMA) in methanol, ethanol, xylene and toluene was measured over the temperatures range from (278 to 338) K by the dynamic method using a laser monitoring observation technique. The solubility in all solvents increased with temperature and the greatest solubility of both systems was obtained in toluene. The Wilson and the NRTL models were applied to correlate the experimental results. The root-mean-square deviations for the system of (CDMB + solvent) ranged from T = (0.11 to 0.34) K and (0.08 to 0.33) K calculated by the Wilson and the NRTL models, respectively, while for the system of (CDMA + solvent) the root-mean-square deviations ranged from T = (0.11 to 0.32) K and (0.14 to 0.33) K. The melting points and enthalpies of fusion of CDMA and CDMB were determined by differential scanning calorimetry (DSC). Toluene was found to be the preferred solvent for the reduction of CDMB to CDMA from the point of view of reaction and product separation

The chemical composition of urinary crystallites of less than 1000 nm from 10 calcium phosphate (CaP) stone-formers were investigated and compared with that from healthy subjects using X-ray power diffraction, Fourier transform infrared spectroscopy and nanoparticle size analyzer. Although there were some calcium oxalate monohydrate (COM) crystals in CaP stones, the main components of crystallites in urine of CaP stone formers were uric acid (UA), CaP and COM, while that in healthy urine was mainly UA and a small amount of COM. That is, the CaP content in urinary crystallites of CaP stone-formers was significantly higher than that of controls. The particle size range of crystallites in lithogenic urine was 3~1000 nm and most of these crystallites were aggregated, but it was 30~500 nm in healthy subjects.

Calcium oxalate dihydrate (COD) nanoparticles with an average size of about 200 nm was prepared by complex precipitation method using potassium oxalate (K2Oxa) and CaCl2 as raw materials, NTA as complexing agent. The effects of initial reactant concentrations, pH in reaction system and dispersion media on morphology and size of the nanoparticles were investigated. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared resonance (FTIR), zetasizer Nano-ZS and transmission electron microscopy (TEM). The results indicated that the prepared sample was COD and its morphology was nearly all elliptical.

Femtosecond laser with the features of ultrashort pulse duration and ultrahigh peak power can achieve “cold” machining. The recast layer and micro-cracks of the hole wall can be ruduced effectively by applying femtosecond laser in processing air-film holes on turbine blades, and the machining accuracy and consistency of the hole shape will increase. In this paper, the high-speed rotating femtosecond laser beam is adopted in several currently used turbine blade materials for air-film holes machining, and high quality air-film holes without hole wall recast layer and micro-cracks are processed through a large number of experiments to optimize machining technology and technological parameter.

This paper investigated the inhibitory effect of degraded soybean polysaccharide (DPS) on the growth of calcium oxalate (CaOxa) crystals. The results were compared with that of soybean polysaccharide without degradation (SPS). The data showed that DPS exhibited a much higher efficiency to inhibit CaOxa growth and stabilize calcium oxalate dihydrate (COD) compared with SPS. As DPS concentration increased, the soluble Ca(2+) ions significantly increased, the aggregation degree of calcium oxalate monohydrate (COM) crystals decreased, the shape of COD crystals became round and blunt, and the Zeta potential on CaOxa crystal surface reduced. The above results were all conducive for the inhibition of CaOxa crystallization. In addition, DPS displayed a distinct repairing effect on oxidative injured renal epithelial cells in African green monkey (Vero), with enhanced cell viability and extracellular superoxide dismutase activity after repair. The morphologies of the repaired cells and their regulatory capability on CaOxa growth were between the control and injured cells. The results indicated that the risk of stone formation can be reduced by DPS, and that DPS may be a potential green drug to prevent the formation of CaOxa stones.

We researched the genetic polymorphisms of vWA in Henan population and its usefulness in forensic science.DNA extracted from non-relative persons in Henan population with Chelex was amplified by polymerase chain reaction and was typed by nondenaturing polyacrylamide gel electrophoresis silver staining.A total of 8 alleles and 19 genotypes were found in Henan population,its heterozygosity is high and the locus can be used in forensic genetics. We obtained the allelic frequency of the locus vWA in Henan population. The results of amniotic fluid,villus,blood stain indicate vWA is a good locus for forensic study.

To investigate the allele frequencies of six short tandem repeats (STR) loci: F13A1, F13B, D8S1179, CSF1PO, D5S818 and TPOX in Han population in Henan province, DNA was extracted with chelex from EDTA-blood samples of the unrelated individuals in Henan province and amplified with PCR technique. The PCR product was analyzed with the undenatured PAGE vertical electrophoresis and silverstain. The results were obtained through genetical analysis. The authors got the number of allele of six loci, Three alleles of F13A1 could be detected in this population. The F13A1 * 7 is the most common allele with a frequency of 45.2%, followed by F13A1 * 5 and F13A1 * 4 respectively. F13B had four alleles among which F13B * 10 has the highest frequency, followed by F13B * 9, F13B * 8, F13B * 11. The 8 alleles of D8S1179 in the order from high to low frequency is D8S1179 * 14, * 15, * 12, * 11, * 10. And the most common frequencies of alleles of CSF1PO, D5S818, TPOX ore CSF1PO * 12, D5S818 * 11, TPOX * 8, respectively followed by the allele of * 11, * 14, * 10, * 13 in CSF1PO locus, and * 12, * 13, * 10, * 9, * 14, * 8, * 15, * 7 in D5S818 locus, * 11, * 9, * 12, * 10 in TPOX locus. The heterozygosities of the six loci were 0.62, 0.46, 0.83, 0.59, 0.78 and 0.65; the discrimination powers were 0.78, 0.66, 0.95, 0.79, 0.92 and 0.82. The heterozygosities of the six loci are high and the frequencies are in good agreement with Hardy-Weinberg equilibrium. The six loci are good as genetic markers. We can use these loci in dividualidentification and partenity test in forensic area.

To increase the efficiency of in vitro transformation of human lymphocytes by Epstein-Barr virus (EBV) and establish permanent lymphoblastoid cell lines from patients with abnormal chromosome karyotype, B lymphoid cells were prepared from cryopreserved heparinized blood samples. The lymphoid cell pellet was resuspended with 0.5 ml medium of RPMI with 20% fetal calf serum(FCS), and added 2 ml virus-containing superatant of the EB virus-producing cell lines by filtrated, and mixed. Four 25 cm2 cell culture bottles were put upright. A total of 2.5 ml of RPMI with 20% FCS was put in each of them. The blood-virus mixture was distributed among the four cell culture bottles as follows: Bottle I, Bottle II, Bottle III and Bottle IV were added with 0.3 ml, 0.6 ml, 1.2 ml and the rest respectively. The cells culture bottles were put into the cell culture incubator in an upright position. After 3 days the cells were puting new medium with 20% FCS as follows: Bottle I 3 ml, Bottle II 4 ml, Bottle III 5 ml and Bottle IV 6 ml. After one week, the medium was changed again as described above. The medium change was conducted until the cells grew very fast. The right ratio between blood cells and virus titer can not be exactly determined for every blood sample, and therefore a dilution series with four different blood/virus ratios was set up. Due to the dilution series, addition of immune inhibitors like cyclosporine, was not necessary. Forty-seven permanent lymphoblastoid cell lines of patients with abnormal chromosome karyotype. Transformed cells were found in only one or two of the four cell culture bottles. The total successive rate increased up to 97.87%. Of the four cell culture bottles, Bottle I, Bottle II, Bottle III and Bottle IV, the successive rates were 6.39%, 61.70%, 31.91% and 8.51% respectively. This method can be used for preserving large number of lymphoblastoid cell lines, and also provide enough research materials for further studies.

The binding and subsequent fate of 125I-labeled bombesin was studied in rat pancreatic acini. At both 37 degrees C and 4 degrees C binding occurred to a single saturable site, with Kd equal to 1.7 nM. The amount of steady-state tracer binding was reduced at 4 degrees C (5.7%/mg protein) compared with 37 degrees C (8.7%/mg), with a similar relative change in calculated binding capacity. With the use of an acid wash procedure to remove surface bound ligand, 55% of cell-associated 125I-bombesin was internalized in the steady state at 37 degrees C but only 5% at 4 degrees C. Preincubation at 4 degrees C followed by an increase to 37 degrees C led to rapid internalization of bound bombesin, which was blocked by the metabolic inhibitor antimycin. 125I-bombesin was found to be degraded by two acinar systems. One was not related to receptor binding but could be inhibited with bacitracin. The other occurred after internalization and was partially blocked with chloroquine. Thus, after binding, bombesin is internalized, and the degradation products are released from the cell. Exposure to bombesin is also accompanied by a subsequent decrease in cell surface binding (54% after 1 h exposure to 100 nM bombesin), suggesting that the bombesin receptor may also be internalized in a ligand-dependent manner.

The effects of bombesin on physiological responses (amylase secretion, protein synthesis) and intracellular mediators [inositol 1,4,5-trisphosphate (1,4,5–IP3), [Ca2+]i, and diacylglycerol] were studied in isolated rat pancreatic acini and compared with the actions of cholecystokinin (CCK). Bombesin stimulated amylase secretion to the same extent as CCK. However, it failed to reproduce the inhibition of amylase secretion by high concentrations of CCK and likewise did not inhibit incorporation of [3H]leucine into protein in contrast to high concentrations of CCK. Low concentrations of bombesin (1–100 pM) induced repetitive oscillations in [Ca2+]i, whereas higher concentrations of bombesin (1–10 nM) induced a large transient increase in [Ca2+]i followed by a small sustained plateau. Bombesin (1–100 nM) induced an early peak of 1,4,5–IP3 at 5–15 s but was without measurable effect at lower concentrations. These effects on [Ca2+]i and 1,4,5–IP3 were similar to those seen with CCK except that bombesin was approximately 10-fold less potent than CCK. Bombesin induced an increase in acinar 1,2-diacylglycerol with a biphasic time course similar to CCK. However, the magnitude of the response to bombesin was much smaller than the response to CCK. The results suggest that bombesin receptors initiate similar intracellular messengers as does CCK. However, CCK induces a larger increase of diacylglycerol and probably an as yet unidentified messenger responsible for its inhibitory effects.

1. The distributions of gastrin- and cholecystokinin-like immunoreactivities in the dog and cat vagus nerves have been studied after nerve section and ligation. 2. In dogs, there was an increase in cholecystokinin-octapeptide-like immunoreactive material on the cranial side of ligatures on the thoracic or cervical vagi. When pairs of ligatures were tied on the cervical vagi there was accumulation proximal, and a slight decrease distal to, the upper ligature. There was also a modest increase distal to the lower ligature. 3. In cats, section of the vagus above the nodose ganglion, and hence degeneration of the efferent fibres, did not prevent increases in cholecystokinin-octapeptide-like immunoreactivity on the cranial side of ligatures which were later tied below the ganglion. Removal of the superior cervical ganglion had no effect on the accumulation of immunoreactive material above the ligatures. Section of the vagus below the nodose ganglion, and hence degeneration of both afferent and efferent fibres, abolished the accumulation on the cranial side of ligatures which were later tied below the section. Cholecystokinin-octapeptide-like material is therefore localized to afferent fibres with cell bodies in the nodose ganglion. 4. Immunoreactive forms were characterized by gel filtration and ion exchange chromatography, and the use of region-specific antisera. In all cats, and all but one dog, a molecule with the properties of sulphated cholecystokinin octapeptide was found to predominate. In some cats (30%) and dogs (26%) a molecule with the properties of heptadecapeptide gastrin (G17) was identified; concentrations of G17 were generally low compared with cholecystokinin octapeptide. In three dogs (20%) there was an accumulation of heptadecapeptide gastrin above the ligatures. 5. Axonal transport of cholecystokinin octapeptide in the vagus is consistent with a neuro-regulatory role for this peptide. However, the functional significance of its localization in afferent fibres, and transport towards the periphery, remains to be determined.

The relationships between molecular forms of gastrin in dog antral mucosa and those in plasma were examined by radioimmunoassay using two regionspecific antisera, and by gel filtration. One antiserum reacts only with intact G-17, the other is Cterminal specific and reacts with G-17, G-34 and their C-terminal fragments. Antral extracts contained predominantly G-17-like immunoreactivity. However, when release of gastrin in conscious or anesthetized dogs was stimulated by feeding, electrical vagal stimulation, instillation of liver extract into the stomach, or by cholinergic drugs

In rats, unilateral electrolytic lesions of the medial forebrain bundle caused an accumulation of CCK8 in the ventral tegmental area on the lesioned side, and a fall in CCK8 concentration in some mesolimbic areas on the same side. The results suggest axonal transport of CCK8 from VTA to mesolimbic forebrain.

Publisher Summary This chapter discusses the role of cholecystokinin octapeptide in the gut. Extracts of the whole thickness of gut wall contain material derived from both mucosal endocrine cells and enteric neurons. To study neuronal CCK free of contamination by endocrine cell material, the advantage of the fact that the longitudinal muscle of guinea pig ileum and jejunum can be stripped from the underlying circular muscle either with or without the adherent myenteric plexus is gained. In guinea-pig jejunum concentrations of immunoreactive CCK in innervated longitudinal muscle were 34 ± 6 pmol/g compared with 138 ± 37 pmol/g in mucosa. There was a sharp distal gradient in mucosal concentrations but a less markedly gradient in the myenteric plexus, so that in ileum, the concentrations in the longitudinal muscle plus plexus were 14 ± 2 pmol/g compared with 5 ± 1 pmol/g in mucosa. Immunoreactive CCK was localized to the myenteric plexus, rather than the muscle itself, as in denervated strips of muscle, the concentrations were reduced by over 70%. The concentrations of CCK-like peptides in the myenteric plexus are relatively low compared with other neuropeptides, substance P, and vasoactive intestinal polypeptide-like immunoreactivity.

Molecular forms of cholecystokinin in rat brain were studied by radioimmunoassay using two new antisera raised against the C-terminal tetrapeptide common to cholecystokinin and gastrin. Evidence is presented to show that one antiserum (L112) reacts at the C-terminus of the tetrapeptide, while the other antiserum (L131) reacts at its N-terminus. With antiserum L112 the predominant immunoreactive form of CCK found in extracts of rat brain corresponded to the C-terminal octapeptide; a minor immunoreactive form eluted from Sephadex G25 between the C-terminal octapeptide and the tetrapeptide. A similar pattern of molecular forms was found using a third antiserum (L48) previously shown to react well with the C-terminal octapeptide and poorly with the C-terminal tetrapeptide. Antisera L112 and L48 also revealed a quantitatively similar distribution of immunoreactive material in different regions of rat and cow brain. In contrast, antiserum L131 failed to demonstrate significant amounts of immunoreactive material in rat brain. It is concluded that the C-terminal octapeptide of cholecystokinin predominates in rat brain and that contrary to findings of previous workers there is little or no free C-terminal tetrapeptide present.