A component of high-grade fetal lung adenocarcinoma diagnosed as the cause of lymph node metastasis

High-grade fetal lung adenocarcinoma (H-FLAC) is a rare type of tumor. There have been no reports demonstrating the degree of metastatic susceptibility of this tumor type. In this report, we describe a case in which 15% of the adenocarcinoma components were H-FLAC diagnosed as the cause of lymph node metastasis. A 75-year-old man presented with suspected primary lung cancer (clinical stage IIA, T2bN0M0) and underwent left upper lobectomy and superior mediastinal lymph node dissection. Postoperative histopathology revealed lung cancer with only lobar bronchial lymph node (#11) metastasis. Approximately 60% of the invasive adenocarcinoma showed a papillary morphology, 25% showed a lepidic morphology, and 15% showed a fetal morphology. The histomorphological and immunohistological features of #11 metastasis were similar to those of H-FLAC. Herein, we report a rare and important case of H-FLAC with proven lymph node metastasis, showing that even a small amount of H-FLAC tissue can cause metastasis.

The Roles and Regulatory Mechanisms of Tight Junction Protein Cingulin and Transcription Factor Forkhead Box Protein O1 in Human Lung Adenocarcinoma A549 Cells and Normal Lung Epithelial Cells

Tight junction (TJ) protein cingulin (CGN) and transcription factor forkhead box protein O1 (FOXO1) contribute to the development of various cancers. Histone deacetylase (HDAC) inhibitors have a potential therapeutic role for some cancers. HDAC inhibitors affect the expression of both CGN and FOXO1. However, the roles and regulatory mechanisms of CGN and FOXO1 are unknown in non-small cell lung cancer (NSCLC) and normal human lung epithelial (HLE) cells. In the present study, to investigate the effects of CGN and FOXO1 on the malignancy of NSCLC, we used A549 cells as human lung adenocarcinoma and primary human lung epithelial (HLE) cells as normal lung tissues and performed the knockdown of CGN and FOXO1 by siRNAs. Furthermore, to investigate the detailed mechanisms in the antitumor effects of HDAC inhibitors for NSCLC via CGN and FOXO1, A549 cells and HLE cells were treated with the HDAC inhibitors trichostatin A (TSA) and Quisinostat (JNJ-2648158). In A549 cells, the knockdown of CGN increased bicellular TJ protein claudin-2 (CLDN-2) via mitogen-activated protein kinase/adenosine monophosphate-activated protein kinase (MAPK/AMPK) pathways and induced cell migration, while the knockdown of FOXO1 increased claudin-4 (CLDN-4), decreased CGN, and induced cell proliferation. The knockdown of CGN and FOXO1 induced cell metabolism in A549 cells. TSA and Quisinostat increased CGN and tricellular TJ protein angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) in A549. In normal HLE cells, the knockdown of CGN and FOXO1 increased CLDN-4, while HDAC inhibitors increased CGN and CLDN-4. In conclusion, the knockdown of CGN via FOXO1 contributes to the malignancy of NSCLC. Both HDAC inhibitors, TSA and Quisinostat, may have potential for use in therapy for lung adenocarcinoma via changes in the expression of CGN and FOXO1.

[Crucial Techniques for Chest Tube Placement and Postoperative Management]

Postoperative management of thoracic surgery with an indwelling chest tube is common, and knowledge about it is essential. A postoperative chest tube has four roles:1) to reinflate the lung, 2) to observe the condition of the thoracic cavity and acquire information regarding the outcomes, 3) to prevent complications, and 4) to treat pulmonary air leaks and empyema (chemical pleurodesis et ct). Although postoperative complications have decreased in recent years following advances in video-assisted thoracoscopic surgery( VATS) and devices such as stapling devices and vascular sealing systems (VSS), postoperative chest tube placement is still common. Therefore, a thorough knowledge of chest tube management is extremely important in thoracic surgery. Here, we have described, in detail, the management of a postoperative chest tube at our hospital.

Combined Exercise and Education Program: Effect of Smaller Group Size and Longer Duration on Physical Function and Social Engagement among Community-Dwelling Older Adults

Background

Exercise, education, and social engagement are critical interventions for older adults for a healthy life expectancy and to improve their physical function.

Objective

To conduct a combined exercise and education (CEE) program for improved social engagement and physical function of older adults.

Design

Based on a short-term program we conducted in our previous study, in this study, the program was conducted for half the number of participants of the earlier study but for a longer duration.

Setting

A community of older adults in Ami, Japan, was the setting of the study.

Participants

23 healthy older adults >65 years living in the community were the participants in the study.

Interventions

Five 80-minute sessions conducted once in two weeks comprised 60-min exercise instruction and 20-min educational lectures per session on health. We examined the improvement in physical and social engagement before and after participation. Physical function and health-related questionnaire data were collected before and after the program.

Results

Data analysis from 15 participants showed improved physical performance but no effect on social engagement.

Conclusions

A higher program frequency, rather than program duration, may be vital to improving exercise performance and social engagement and maximizing the effects of high group cohesion in small groups. Further studies are needed to develop more effective interventions to extend healthy life expectancy.

[Minimally Invasive Robot-assisted Thoracoscopic Surgery for Mediastinal Tumor]

Robot-assisted thoracoscopic surgery( RATS) and video-assisted thoracoscopic surgery are minimally invasive surgical approaches to the chest wall that avoid sternotomy. We report on the innovations in RATS mediastinal tumor surgery performed in our department. We use a lateral approach, and the robotic arm is inserted between the third, fifth, and seventh intercostals and below the costal ribs. Carbon dioxide gas is insufflated using a pneumoclear insufflator. A small thoracotomy is made in the fifth intercostal space and an Alnote Lapsingle is placed and a scope and assistant port are implanted. The Alnote Lapsingle is used to keep the chest wall airtight and stable. The scope is moved less, reducing interference with the assistant. Tissue can now be placed in the retrieval bag with a good surgical field of view. After much trial and error, RATS mediastinal tumor surgery can now be performed more easily.

[Mullerian Cyst in the Posterior Mediastinum Resected by Robot-assisted Thoracic Surgery:Report of a Case]

Mullerian cyst in the posterior mediastinum is a rare disorder. We report on the case of a woman in her 40s with a cystic nodule which is located in the right posterior mediastinum next to the vertebra at the level of tracheal bifurcation. The tumor was suggested to be cystic by preoperative magnetic resonance imaging (MRI). The tumor was resected with robot-assisted thoracic surgery. Pathology by hematoxylin-and-eosin (H&E) revealed a thin-walled cyst lined by ciliated epithelium without cellular atypia. The diagnosis of Mullerian cyst was confirmed by immunohistochemical staining which showed the positive findings for estrogen receptor (ER) and progesterone receptor of the lining cells.

[Novel Surgical Techniques for Lung Segmentectomy of Malignant Lung Tumors]

For a long time, lobectomy and lymph node dissection have been the standard surgery for treating non-small cell lung cancer. Recently, segmentectomy has been introduced as an alternative surgical procedure for treating early-stage lung cancer. Moreover, a growing number of segmentectomies are performed due to the increasing number of elderly patients, and the expansion of indications, including early- stage lung cancer with a ground glass nodule or peripheral nodule under 2 cm in diameter. However, the use of segmentectomy remains under debate. We have been performing thoracoscopic lung segmentectomy for malignant lung tumors since 2003. The number of surgeries has increased over the past few years, since robot-assisted lung resection of the right lobe became covered by health insurance in April 2018. In addition, lung segmentectomy is performed for lung metastases of malignant tumors in other organs. In deciding on the surgical approach, the increased technical difficulty of segmentectomy compared to lobectomy, owing to the anatomical complexity of the peripheral vessels and bronchi, needs to be considered, and novel surgical procedures and preoperative planning based on three-dimensional computed tomography( CT) images are necessary. We describe the preoperative management and surgical techniques used in approximately 250 lung segmentectomy procedures performed at our hospital up to May 2022, with no conversion to thoracotomy.

[Thoracoscopic Superior and Subsuperior Segmentectomy of the Right Lower Lung for Lung Cancer]

The subsuperior segment (S*) is not frequently observed between the superior (S6) and posterior basal segments (S10). We present a case of video-assisted thoracoscopic surgery of S6+S* segmentectomy for a primary lung cancer patient. A 71-year-old man with a 20-mm nodule on the right S6, suspected of primary lung cancer( cT1bN0M0, stageⅠA2), was admitted to our hospital. Three-dimensional chest computed tomography (CT) revealed a subsuperior segmental bronchus (B*), originating from the common trunk of the lateral basal segmental bronchus( B9) and posterior basal segmental bronchus (B10). In order to obtain enough surgical margin, we performed S6+S* segmentectomy. The pathological diagnosis was invasive adenocarcinoma( pT1cN0M0, stageⅠA3). S* segmentectomy was considered to be useful method to ensure sufficient surgical margin when the lesion is in S* or in segments adjacent to it.

Causes and management of intraoperative complications in robot-assisted anatomical pulmonary resection for lung cancer

Background

To perform safe robot-assisted anatomical lung resections, the details of intraoperative complications need to be shared among thoracic surgeons. However, only limited data are available.

Methods

This retrospective, single-institutional study evaluated 134 patients who underwent robot-assisted anatomical lung resection. We examined the causes, management, and outcomes of all intraoperative complications.

Results

Of the 134 eligible patients, 118 (88%) underwent lobectomy and 16 (12%) underwent segmentectomy. Intraoperative complications occurred in 17 (12.7%) patients. These complications included pulmonary artery (PA) injuries in seven patients, pulmonary vein (PV) injuries in three, azygos vein (AV) injury in one, superior vena cava (SVC) injury in one, bronchial injuries in three, and lung injuries in four. Most PA injuries were at a distal side and controlled by pressure, fibrin sealant, or stapling of the proximal side. In the three PV injuries, right upper PV was sandwiched by robotic instruments, V6 was punctured by the tip of the Maryland bipolar forceps, and the distal side of V2t was injured during tunneling of a minor interlobar fissure. These were controlled the same way as the PA injuries. The AV injury occurred during hilar lymph node (LN) dissection and was controlled by suturing. The SVC injury was caused by interference of the robotic forceps and the suction tube outside the field of view during upper mediastinal LN dissection. The injury was controlled by continuous pressure while layering polyglycolic acid sheets and fibrin glue. In the three bronchial injuries, B10 was injured during subcarinal LN dissection, right main bronchus was injured during upper bronchus dissection and the stapling failure of the bronchus occurred by strong traction. They were all repaired by suturing. All lung parenchymal injuries were caused by manipulation of robotic instruments outside the field of view. The lung injuries were repaired by suturing with pledgets. No cases were converted to thoracotomy. The 30-day mortality rate was 0.7%. The cause of mortality was pneumonia.

Conclusions

In robot-assisted anatomical pulmonary resection for lung cancer, most major intraoperative complications can be safely managed robotically without conversion to thoracotomy.

Robot-assisted and video-assisted thoracoscopic surgery for thymoma: comparison of the perioperative outcomes using inverse probability of treatment weighting method

Background

Minimally invasive surgery is the standard treatment for early-stage thymoma. We compared the perioperative outcomes between robot-assisted thoracoscopic surgery (RATS) and video-assisted thoracoscopic surgery (VATS) for thymoma.

Methods

Between April 2011 and August 2021, patients with thymoma who underwent thymectomy by RATS (n=20) or VATS (n=37) at our hospital were retrospectively reviewed. We evaluated the postoperative quality of life (QOL), surgical outcomes, complications, mortality, and pain grade. Postoperative QOL was assessed according to the time to achieve “B duration” and “CIII duration” based on the Nursing Dependency Score and Nursing Criteria, respectively.

Results

After the inverse probability of treatment weighting (IPTW), the B duration and CIII duration were significantly shorter with RATS than with VATS (P<0.001 and P=0.037, respectively). These superior results of RATS group compared to those of the VATS group were confirmed with logistic regression analysis (OR 0.25, 95% CI: 0.10–0.63, P=0.003; and OR 0.31, 95% CI: 0.12–0.76, P=0.011, respectively). After the IPTW, the VATS group had significantly fewer patients with epidural analgesia than the RATS group (P=0.018). In contrast, additional regular analgesics (including those for wound pain and neuralgia) were prescribed significantly more often during postoperative hospitalization in the VATS group (P=0.033). Patients in both groups had no myasthenic crisis or mortality. The postoperative pain grade at the first and second follow-ups did not significantly differ between the two groups after the IPTW (P=0.376 and P=0.109, respectively).

Conclusions

RATS offered the advantages of improved postoperative QOL according to nursing care systems compared to VATS.

LSR antibody promotes apoptosis and disrupts epithelial barriers via signal pathways in endometrial cancer

Lipolysis-stimulated lipoprotein receptor (LSR), a lipid metabolism-related factor localized in tricellular tight junctions (tTJs), plays an important role in maintaining the epithelial barrier. LSR is highly expressed in well-differentiated endometrial endometrioid carcinoma (EEC), and its expression decreases during malignancy. Angubindin-1, a novel LSR ligand peptide, regulates tTJs without cytotoxicity, enhances paracellular permeability, and regulates epithelial barrier via c-Jun N-terminal kinase (JNK)/cofilin. In this study, we investigated the immune-modulatory roles of an anti-LSR antibody in the treatment of EEC in vitro compared to those of angubindin-1. We prepared an antibody against the extracellular N-terminal domain of human LSR (LSR-N-ab) and angubindin-1. EEC cell-line Sawano cells in 2D and 2.5D cultures were treated with 100 μg/ml LSR-N-ab or 2.5 μg/ml angubindin-1 with or without protein tyrosine kinase 2β inhibitor PF431396 (PF43) and JNK inhibitor SP600125 (SP60) at 10 μM. Treatment with LSR-N-ab and angubindin-1 decreased LSR at the membranes of tTJs and the activity of phosphorylated LSR and phosphorylated cofilin in 2D culture. Treatment with LSR-N-ab and angubindin-1 decreased the epithelial barrier measured as TEER values in 2D culture and enhanced the epithelial permeability of FD-4 in 2.5D culture. Treatment with LSR-N-ab, but not angubindin-1, induced apoptosis in 2D culture. Pretreatment with PF43 and SP60 prevented all the changes induced by treatment with LSR-N-ab and angubindin-1. Treatment with LSR-N-ab and angubindin-1 enhanced the cell metabolism measured as the mitochondrial respiration levels in 2D culture. LSR-N-ab and angubindin-1 may be useful for therapy of human EEC via enhanced apoptosis or drug absorption.

Inhibition of HDAC and Signal Transduction Pathways Induces Tight Junctions and Promotes Differentiation in p63-Positive Salivary Duct Adenocarcinoma

Simple Summary

The p53 family p63 gene is essential for the proliferation and differentiation of various epithelial cells, and it is overexpressed in some salivary gland neoplasia. Histone deacetylases (HDACs) are thought to play a crucial role in carcinogenesis, and HDAC inhibitors downregulate p63 expression in cancers. p63 is not only a diagnostic marker of salivary gland neoplasia, but it also promotes the malignancy. Inhibition of HDAC and signal transduction pathways inhibited cell proliferation and migration, induced tight junctions, and promoted differentiation in p63-positive salivary duct adenocarcinoma (SDC). It is, therefore, useful in therapy for p63-positive SDC cells.

Abstract

Background: The p53 family p63 is essential for the proliferation and differentiation of various epithelial basal cells. It is overexpressed in several cancers, including salivary gland neoplasia. Histone deacetylases (HDACs) are thought to play a crucial role in carcinogenesis, and HDAC inhibitors downregulate p63 expression in cancers. Methods: In the present study, to investigate the roles and regulation of p63 in salivary duct adenocarcinoma (SDC), human SDC cell line A253 was transfected with siRNA-p63 or treated with the HDAC inhibitors trichostatin A (TSA) and quisinostat (JNJ-26481585). Results: In a DNA array, the knockdown of p63 markedly induced mRNAs of the tight junction (TJ) proteins cingulin (CGN) and zonula occuludin-3 (ZO-3). The knockdown of p63 resulted in the recruitment of the TJ proteins, the angulin-1/lipolysis-stimulated lipoprotein receptor (LSR), occludin (OCLN), CGN, and ZO-3 at the membranes, preventing cell proliferation, and leading to increased cell metabolism. Treatment with HDAC inhibitors downregulated the expression of p63, induced TJ structures, recruited the TJ proteins, increased the epithelial barrier function, and prevented cell proliferation and migration. Conclusions: p63 is not only a diagnostic marker of salivary gland neoplasia, but it also promotes the malignancy. Inhibition of HDAC and signal transduction pathways is, therefore, useful in therapy for p63-positive SDC cells.

CCR5 is required for regulation of alloreactive T-cell responses to single class II MHC-mismatched murine cardiac grafts

The effector CD4 T-cell response in wild-type C57BL/6 recipients of single class II MHC-disparate B6.H-2(bm12) cardiac allografts is restricted by CD4(+)CD25(+) regulatory T cells (Tregs) resulting in long-term allograft survival. To investigate the role chemokine receptors might play in Treg function, this study tested the requirement for CCR5 on Tregs to suppress the alloimmune response in C57BL/6 recipients of B6.H-2(bm12) cardiac allografts. In contrast to the long-term survival of B6.H-2(bm12) allografts in wild-type recipients (>100 days), the allografts were acutely rejected within 25 days in CCR5(-/-) recipients with intense infiltration of CD4 T cells. Numbers and duration of donor-reactive CD4 T cells producing IFN-gamma and IL-4 were markedly increased in spleens of B6.CCR5(-/-) versus wild-type recipients. Wild-type and B6.CCR5(-/-) mice had equivalent numbers of splenic FoxP3(+) Tregs before and following transplantation, and these Tregs were equivalently suppressive in vitro. However, diminished numbers of FoxP3(+) Tregs infiltrated B6.H-2(bm12) allografts in B6.CCR5(-/-) recipients. Adoptive transfer of wild-type, but not CCR5-deficient, CD4(+)CD25(+) Tregs to CCR5(-/-) recipients restored long-term survival of B6.H-2(bm12) cardiac grafts. Collectively, these results indicate that CCR5 expression is required for the regulatory functions of Tregs that restrict alloreactive CD4 T-cell responses to single class II MHC-mismatched cardiac allografts.

The efficient use of microcolumns in chromatographic systems

Microcolumn techniques involving pre-column concentration and post-column derivatization make good use of micro-scale high-performance liquid chromatography. The efficient use of microcolumns is illustrated by some applications to the analysis of amino acids, bile acids and catecholamines. The potential of new detector techniques based on the multichannel photodiode array detector, and on immobilized enzyme post-column reaction systems with fluorimetric detection, is also discussed.

Urodynamics in a rat neurogenic bladder model with a unilateral electrolytic lesion of the basal forebrain

OBJECTIVE

To investigate the changes in bladder function in rats with an electrolytic lesion of the right basal forebrain (RBF) and to determine the effects of AH-9700, a novel sigma receptor ligand, on cystometry in RBF-lesioned rats.

MATERIALS AND METHODS

A lesion was made electrolytically in the RBF of male Wistar rats. At 7 or 8 days after the lesion or sham surgery, continuous cystometry was performed in awake rats. In addition, contractile responses to electrical field stimulation or carbachol were measured in isolated bladder strips, as were the forebrain contents of acetylcholine, monoamine neurotransmitters and their metabolites.

RESULTS

RBF-lesioned rats showed a remarkable increase in voiding frequency, with a decrease in voiding threshold pressure but no change in voiding pressure, compared with sham-operated rats. However, contractile responses in bladder strips isolated from RBF-lesioned rats were no different from those in strips isolated from sham-operated rats. In RBF-lesioned rats, the contents of acetylcholine, dopamine, 4-dihidroxyphenylacetic acid and homovanillic acid were significantly decreased in the right forebrain. AH-9700 dose-dependently decreased the voiding frequency and increased the threshold pressure in RBF-lesioned rats. Anti-muscarinic agents (oxybutynin and propiverine) also decreased the voiding frequency, but their effects were less potent than that of AH-9700.

CONCLUSIONS

The RBF-lesioned rat may be a useful model for the neurogenic bladder of supraspinal origin. Moreover, AH-9700 effectively improves bladder dysfunction in this model.

Pharmacological effect of amezinium on urethra and bladder of rabbits

The pharmacological effect of amezinium on the urethra and bladder of rabbits was investigated. Amezinium produced concentration-dependent contractions in isolated urethral strips. The maximum response was approximately 30% of that caused by norepinephrine (NE). The concentration-response curve of NE was shifted to the left by amezinium. Moreover, amezinium enhanced the relaxative effect of NE on carbachol-induced contractions in isolated bladder strips. In anesthetized rabbits, amezinium significantly increased the intraurethral pressure (IUP) but produced only slight increases in mean blood pressure (MBP). Pre-treatment with amezinium ehhanced NE-induced increases in IUP index and MBP. The enhancing effect on the IUP index lasted much longer than that on MBP. In a stress incontinence model amezinium significantly inhibited the incontinence after an i.v. infusion of a low dose of NE. This effect was antagonized by pre-treatment with prazosin. These results suggest that amezinium may produce an excellent effect for stress incontinence, especially mixed, without severe adverse events such as sudden hypertension.

Effects of AH-9700, (+)-pentazocine, DTG and oxybutynin on micturition in anesthetized rats with acetone-induced cystitis

We investigated the effects of AH-9700 (1-[2-(3,4-dihydro-6,7-dimethyl-2-naphthalenyl)ethyl] pyrrolidine fumarate; a novel sigma receptor ligand), (+)-pentazocine and 1,3-di-o-tolylguanidine (DTG) (two typical sigma receptor ligands), and oxybutynin (a currently used anti-pollakiuria drug) on cystometrograms in anesthetized rats with 30% acetone-induced cystitis. Compared to sham-treated rats, acetone-treated cystitis models exhibited an increase in urinary frequency during continuous filling cystometry. Intravenous administration of AH-9700 (1-5 mg/kg), (+)-pentazocine or DTG to the rats with cystitis dose-dependently prolonged micturition intervals and increased the micturition threshold pressure. Oxybutynin (1 mg/kg. i.v.) also extended micturition intervals, but decreased the micturition pressure. These results indicate that AH-9700, (+)-pentazocine and DTG improve abnormal frequent urination caused by acetone-induced cystitis in a manner different from that of oxybutynin.

Pharmacological actions of AH-9700 on micturition reflex in anesthetized rats

In radioligand binding assays, AH-9700 (1-[2-(3,4-dihydro-6,7-dimethyl-2-naphthalenyl)ethyl]pyrrolidine fumarate) had high affinity for sigma receptors and moderate affinity for muscarinic receptors. The affinity of AH-9700 for sigma(1) receptors was significantly reduced in the presence of 5'-guanylyl-imidodiphosphate (GppNHp). In isolated bladder strips of rats, AH-9700 inhibited carbachol-induced contractions. In anesthetized rats, i.v. administration of AH-9700 and typical sigma receptor ligands, (+)-pentazocine and 1,3-di-o-tolylguanidine (DTG), but not oxybutynin, dose-dependently inhibited rhythmic isovolumetric reflex bladder contractions. AH-9700 and oxybutynin suppressed the amplitude of rhythmic bladder contractions. On the other hand, at doses lower than used i.v., the i.c.v. administration of AH-9700 or the sigma receptor ligands inhibited rhythmic bladder contractions without suppressing the amplitude. This inhibitory effect of AH-9700 was markedly reduced by pretreatment with i.c.v. pertussis toxin. These results suggest that AH-9700 exerts a marked anti-micturition reflex effect through central sigma receptors possibly related to pertussis toxin-sensitive Gi/o-proteins and a moderate spasmolytic effect based on its peripheral anti-muscarinic activity.

Determination of alcohols in alcoholic beverages by micro high-performance liquid chromatography with indirect photometric detection

Aliphatic alcohols in alcoholic beverages were determined by micro high-performance liquid chromatography with indirect photometric detection. Theophylline was added to the mobile phase as the visualization agent. Ethanol, propanols and butanols could be determined by this method.

Multiple detection system for the high-resolution microcolumn size-exclusion chromatographic separation of proteins with a slurry-packed capillary column

A multiple (triple) detection system with one detector and recorder each was developed for the high-resolution size-exclusion chromatographic separation of proteins with a slurry packed capillary column. Fused-silica capillary columns of length 1, 2.5 and 6 m and I.D. 0.26 mm were connected in this order by joining each end of the shorter column to the top of the longer column through flow-through cells installed side-by-side on a cell block in the detector. By this means it was possible to record the chromatograms three times with one injection. This system is convenient for comparing the chromatograms obtained with different plate numbers and for effecting very high-resolution separations.

Enantiomeric separation of amino acids by micro high-performance liquid chromatography on an L-proline-bonded stationary phase

Enantiomeric separation of amino acids on an L-proline-bonded phase was examined in micro high-performance liquid chromatography. Gradient separation of seven pairs of racemic dansyl amino acids was achieved by connecting chiral and hydrophobic columns in series.

Rat insulin-like growth factor II gene. A single gene with two promoters expressing a multitranscript family

We have characterized the single-copy rat gene encoding the protein precursor of insulin-like growth factor II (pre-pro-rIGF-II) that is located downstream from and in the same transcriptional orientation as the homologous insulin II gene (5'-insulin-IGF-II-3'). This gene consists of at least three coding exons and utilizes two promoters that generate alternate 5' non-coding exons. Multiple transcripts from both promoters appear primarily in fetal or neonatal tissues (in all of the developmental stages and tissues that we have examined), but they are extremely rare or undetectable in adult tissues, with the exception of the brain and the spinal cord. These transcripts, which exhibit characteristic developmental profiles in various tissues, differ both in the presence of one of the alternate 5' non-coding exons and in the length of their fourth exon. The possible occurrence of differential splicing or differential polyadenylation (or both) in this region is discussed.

Direct coupling of micro high-performance liquid chromatography with fast atom bombardment mass spectrometry. II. Application to gradient elution of bile acids

A new system without a moving belt has been developed for direct coupling of micro high-performance liquid chromatography with fast atom (xenon or argon) bombardment mass spectrometry. The structure of the interface was basically the same as used previously, but the mass spectrometer was modified by adding both a liquid nitrogen trap between the ion source housing and the diffusion pump, and a position adjuster for the interface. Stable ionization of the solute in a glycerol matrix is achieved at flow-rates below 2 microliter/min. The system was applied to the analysis of bile acids by gradient elution chromatography. Steady baselines were observed in the mass chromatograms.