Successful treatment of pancreatic accessory splenic hamartoma by laparoscopic spleen-preserving distal pancreatectomy: A case report

BACKGROUND

Pancreatic accessory spleen (PAS) is an uncommon congenital abnormality of the spleen. Spleen hamartoma (SH) is also rare. Moreover, hamartoma in the PAS has not been reported thus far. We report the first case here.

CASE SUMMARY

A 26-year-old male presented with a one-month history of left upper quadrant abdominal pain, and computerized tomography (CT) examination suggested a mass in the pancreas tail. The patient then attended our hospital for diagnosis and treatment. Ultrasonography, CT, and magnetic resonance imaging revealed a solid mass with cystic degeneration growing from the tail of the pancreas. The tumor marker carbohydrate antigen 19-9 (CA19-9) increased to 96.7 U/mL (normal range 0-37 U/mL). An epidermoid cyst in a PAS was considered preoperatively. However, a malignant tumor cannot be ruled out. We performed laparoscopic surgery, and two pancreatic masses were found growing from the pancreatic tail. The two masses were so closely connected that preoperative imaging examinations suggested only one mass. We carefully isolated the masses from the splenic artery and vein. A laparoscopic spleen-preserving distal pancreatectomy was successfully performed. On pathological examination, the masses were well-defined, homogeneous red-tan, 4 × 3, and 4.5 × 1.5 in size, respectively. One of them was cystically degenerated. On microscopical examination, the mass contained unorganized small slit-like vascular channels enclosing red blood cells and lined with plump endothelial cells. No area of cytologic atypia was identified. Focal lymphoid aggregates were found in the intravascular areas. White pulp or fibrosis was not observed. The final diagnosis was pancreatic accessory SH with cystic degeneration. After the operation, CA19-9 was reduced to normal. The patient recovered well, and the 34-mo follow-up period was uneventful.

CONCLUSION

Here, we report the first case of pancreatic accessory SH. A laparoscopic spleen-preserving distal pancreatectomy was successfully performed. The patient recovered well and had a good prognosis.

[Clinicopathological features of hepatic fibrinogen storage disease in children]

Objective: To investigate the clinicopathological and molecular characteristics of hepatic fibrinogen storage disease (FSD) in children. Methods: The clinical, histopathologic, immunophenotypic, ultrastructural and gene sequencing data of 4 FSD cases were collected from September 2019 to January 2021 in the Children's Hospital of Fudan University, Shanghai, China. Retrospective analysis and literature review were conducted. Results: There were 4 cases of FSD, 3 males and 1 female, aged 3 years and 3 months to 6 years (median age, 3 years and 4 months). The clinical manifestations were abnormal liver function and abnormal blood coagulation function, for which 2 cases had family genetic history. Liver biopsies revealed that, besides liver steatosis, fibrosis and inflammation, there were single or multiple eosinophilic inclusion bodies of various sizes and surrounding transparent pale halo in hepatocytes. Immunohistochemistry showed that the inclusion bodies were positive for anti-fibrinogen. Under the electron microscope, they corresponded to the dilated cisternae of the rough endoplasmic reticulum, which were occupied by compactly packed tubular structures and arranged into a fingerprint-like pattern with curved bundles. Gene sequencing revealed that the 2 cases of FGG mutation were located in exon 8 c.1106A>G (p.His369Arg) and c.905T>C (p.Leu302Pro), and 1 case was located in exon 9 c.1201C>T (p.Arg401Trp). No pathogenic variant was detected in the other case. Conclusions: FSD is a rare genetic metabolic disease and clinically manifests as abnormal liver function with hypofibrinogenemia. In the background of liver steatosis, fibrosis and inflammation, there are eosinophilic inclusions with pale halo in the hepatocytic cytoplasm, which can be identified by anti-fibrinogen immunohistochemical staining. The fingerprint-like structures under electron microscope are helpful for the diagnosis, while FGG sequencing detects the pathogenic mutation of exon 8 or 9 that can clearly explain the phenotype. However, the diagnosis of FSD cannot be completely ruled out if the relevant mutations are not detected.

Successful treatment of pancreatic schwannoma by enucleation: A case report

RATIONALE

Pancreatic schwannomas are extremely rare and are difficult to diagnose preoperatively. Over the past 50 years, only 96 cases of pancreatic schwannoma have been reported in English literature. Herein, we report a case of pancreatic schwannoma treated with enucleation.

PATIENT CONCERNS

A 66-year-old woman visited a local hospital due to ventosities. Ultrasonography and computed tomography revealed a pancreatic mass. She visited our hospital for further diagnosis and treatment.

DIAGNOSIS AND INTERVENTIONS

Magnetic resonance imaging revealed a tumor in the pancreatic body, and a solid pseudopapillary tumor was considered preoperatively. During the surgery, a pancreatic mass was found growing in the pancreatic body and tail. A successful tumor enucleation was performed. The mass was 7 × 6 × 3 cm in size with a thin capsule. Pathological examination revealed that the tumor was mainly composed of spindle-shaped cells with a palisading arrangement and no atypia. Both hypercellular and hypocellular areas were visible. Immunohistochemical staining showed that protein S-100 was strongly positive. The tumor was diagnosed as a benign schwannoma originating from the pancreatic body and tail.

OUTCOMES

Postoperatively, the patient showed good recovery. During the 24-month follow-up period, the patient remained well and free of complications.

LESSONS

Pancreatic schwannomas are extremely rare and difficult to diagnose using imaging examinations. Enucleation is a safe and efficacious treatment for exophytic pancreatic schwannomas.

Primary cystic and solid neuroendocrine tumor of the retroperitoneum: A case report

RATIONALE

Primary neuroendocrine tumors (NETs) of the retroperitoneum are extremely rare. The purpose of this case report is to highlight the unusual growth pattern and radiologic features of primary retroperitoneal NETs.

PATIENT CONCERNS

A 46-year-old woman was found to have a retroperitoneal cystic and solid mass during a physical checkup.

DIAGNOSES

The mass was mainly multiseptated in the cystic portion and had a bead-like, lobulated appearance. The solid portion showed restricted diffusion on diffusion-weighted imaging and obvious homogeneous enhancement. The cystic portion showed ring-like and septal enhancement. The patient was diagnosed with a grade 2 (G2) NET of the retroperitoneum after surgery.

INTERVENTIONS

The patient underwent resection of the large retroperitoneal tumor.

OUTCOMES

The patient returned 20 months later with tumor recurrence in the retroperitoneum. She was enrolled in a clinical trial for sulfatinib, and the mass was considerably reduced in size after 4 months. During a nearly 1.5-year follow-up, the mass gradually became slightly enlarged. The expression of somatostatin receptor 2 (SSTR2) was detected, and somatuline was administered as the current treatment.

LESSONS SUBSECTIONS

When a retroperitoneal mass presents as a well-defined cystic or solid hypervascular mass with a fibrous capsule, a primary retroperitoneal NET should be considered in the differential diagnosis.

A five year CT surveillance of ciliated retroperitoneal foregut cyst resembling a cystic pancreatic lesion: A case report

INTRODUCTION

Ciliated retroperitoneal foregut cysts are rare, and to obtain a preoperative definitive diagnosis of this condition is relatively difficult. In addition, the exact mechanism and formation of ciliated retroperitoneal foregut cysts remains unknown.

CASE PRESENTATION

Here, we report a case of a 47-year-old woman who presented with an unusual shaped cystic lesion associated with a patch of solid components between the pancreas and the left kidney, initially misdiagnosed as a cystic pancreatic lesion 5 years previously to presentation at our clinic. During the past years, reports relating to the surveillance of these lesions described that their shapes progressively change while its volumes remain invariably unchanged. We did not observe this phenomenon in any literatures to our knowledge. The patient was diagnosed with ciliated retroperitoneal foregut cyst with remote hemorrhage, after the laparoscopic surgery.

CONCLUSIONS

Ciliated retroperitoneal foregut cysts have characteristic manifestations. From this case, we summarized that cysts in the retroperitoneum, associated with a changing shape of the lesion, highly suggest the diagnosis of foregut cysts, which are safe under long-term surveillance.

[Clinical features, diagnosis and treatment of intraductal papillary neoplasm of the bile duct]

Objective: To study the clinicopathologic features of intraductal papillary neoplasm of the bile duct(IPNB) and to analyze the diagnostic and therapeutic patterns. Methods: The data of 46 patients with IPNB undergoing surgery in Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital of Zhejiang University School of Medicine from January 2013 to November 2017 were retrospectively analyzed.There were 23 males and 23 females with age of (64±8)years.Patients were followed up by clinics and telephone inquiry.Categorical data were compared with χ(2) test or Fisher's exact test. Results: Abdominal pain(in 31 patients), fever (in 15 patients) and jaundice (in 11 patients) were the most common symptoms.Twenty-five patients were accompanied with cholangiolithiasis and 25 were accompanied with liver atrophy.Preoperative laboratory examination was mainly manifested as the abnormal liver function caused by biliary obstruction.Typical imaging findings included bile duct dilation (in 45 patients) and mass within bile duct (in 22 patients). All the patients were diagnosed as IPNB histopathologically.Among them, high-grade intraepithelial neoplasia and related adenocarcinoma were more common in mucus-hypersecretion IPNB ((13/15 vs. 51.6%(16/31))(χ(2)=5.331, P=0.021). Hepatectomy was performed in 25 patients, hepatectomy combined with biliary resection and reconstruction in 12 cases, biliary resection and reconstruction in 3 cases, pancreatoduodenectomy in 3 cases, hepatopancreaticoduodenectomy in 1 case, liver transplantation in 1 case and radiofrequency ablation in 1 case.Forty-one patients were followed up with a median of 30 (12, 41) months.Seven patients suffered recurrence and 6 died. Conclusion: IPNB is a rare disease with limited knowledge currently.Images are the main diagnositc means and surgery is the first choice.

Multiple Lymphomatous Polyposis of the Intestine with Ileocecal Intussusception Due to Mantle Cell Lymphoma: A Case Report of a 34-Year-Old Man

BACKGROUND Multiple lymphomatous polyposis of the gastrointestinal tract can be associated with the B-cell lymphoma variant, mantle cell lymphoma, with most cases having been described in patients who are more than 50 years-of-age. A rare case of multiple lymphomatous polyposis due to mantle cell lymphoma is reported in a 34-year-old man. CASE REPORT A 34-year-old man presented with paroxysmal abdominal pain followed by spontaneous remission, which had been previously diagnosed as gastritis. An episode of ileocecal intussusception occurred, which was confirmed on imaging studies. The diagnosis of multiple lymphomatous polyposis due to mantle cell lymphoma was confirmed following ileocecal resection and histopathology. The patient refused to receive chemotherapy following surgery. Currently, at two-year follow-up, no further abnormality has been found. A review of the literature has shown the importance of endoscopic evaluation in the diagnosis of lymphomatous polyposis. CONCLUSIONS Multiple lymphomatous polyposis due to mantle cell lymphoma has rarely been described in young patients under the age of 50 years. Gastrointestinal endoscopic examination is important for the early diagnosis of multiple lymphomatous polyposis.

Modified-FOLFIRINOX in metastatic pancreatic cancer: A prospective study in Chinese population

FOLFIRINOX chemotherapy has shown remarkable responses in patients with metastatic pancreatic cancer (MPC), and has significantly improved prognosis. However, FOLFIRINOX is currently not frequently applied in China because of its high incidence of adverse events, and there is no recognized optimization for this therapy in Chinese population. Modification of FOLFIRINOX may be better for its acceptance in China. In this study, we evaluated the efficacy and safety of modified-FOLFIRINOX in patients with MPC. A total of 62 MPC patients were treated with modified-FOLFIRINOX (no Fluorouracil bolus, 85% Oxaliplatin and 75% Irinotecan) between April 2014 and April 2017 in our institute. 40 of them were evaluated, with a response rate of 32.5% (13/40). The frequent grade 3/4 adverse events are neutropenia (29%) and alanine aminotransferase elevation (14.5%). No treatment-related death was observed. The median overall survival and median progression-free survival are 10.3 months and 7.0 months, respectively. In conclusion, modified-FOLFIRINOX had significantly improved tolerance with similar efficacy to FOLFIRINOX. These findings may provide evidence for the use of FOLFIRINOX in Chinese patients with MPC.

A case report of spontaneous rupture of intracranial epidermoid cyst with dramatic increase of serum carbohydrate antigen 199: a three-year follow-up study

Background

Tumor markers are widely applied in clinical practice, however, few serum markers have been found for intracranial tumors. Herein, we firstly report an intracranial epidermoid cyst case with extremely high level of serum CA 199. Furthermore, the relationship between CA 199 level and intracranial epidermoid cyst was closely followed for a long period.

Case presentation

We report a case of 41-year-old man with a history of 2 months’ headache and sudden exacerbation for 3 days. Radiology examination suggested multiple lesions spreading along ventricular system. Laboratory tests showed exceeding increase of serum CA 199. The patient underwent craniotomy and continuous lumber drainage. Post-operative pathology proved a ruptured intracranial epidermoid cyst. MRI scans and serum CA 199 were closely followed up for three years.

Conclusion

This case suggests an important role of serum CA 199 in the diagnosis and follow-up of intracranial epidermoid cyst. Ruptured intracranial epidermoid cyst should be considered for a sudden onset case with multiple intracranial lesions and dramatically increased serum CA 199.

Pelvic solitary plasmacytoma: computed tomography and magnetic resonance imaging findings with histopathologic correlation

Objective

To describe the imaging features of pelvic solitary plasmacytoma and to correlate them with the pathologic grade.

Materials and Methods

A retrospective study was performed on the imaging features of 10 patients with a histological diagnosis of pelvic solitary plasmacytoma. The imaging studies were assessed for bone expansion, cortical destruction, signal intensity/density of soft tissue mass and enhancement manifestations, which were then correlated to the pathologic grade.

Results

The imaging features of pelvic solitary plasmacytoma revealed 3 different types: multilocular type (n = 5), unilocular type (n = 2) and complete osteolytic destruction type (n = 3) on computed tomography and MRI. Pathologically, the tumors were classified into low, intermediate and high grades. Features such as multilocular change, perilesional osteosclerosis, slight expansion, local bone cortex disruptions and masses inside bone destruction, often suggest a low-grade solitary plasmacytoma; complete osteolytic destruction, huge soft tissue mass, and osseous defects imply a higher pathologic grade.

Conclusion

Pelvic solitary plasmacytoma has various imaging manifestations, while a slight expansile osteolytic feature with multilocular change or homogeneous enhancement highly suggests its diagnosis. The distinctive imaging features of pelvic solitary plasmacytoma are well correlated to the pathologic grade.

[Effect of nasal cavity expansion surgery on chronic nasal obstructive diseases on the blood supply of the cerebral arterial system]

OBJECTIVE

To investigate the effect of nasal cavity expansion surgery on the abnormal blood supply of the cerebral arterial system.

METHODS

Fifty-nine inpatients with abnormal blood supply of cerebral arterial system confirmed by transcranial doppler (TCD) and chronic nasal obstructive diseases were included in this study. All patients accepted nasal cavity expansion surgery and were followed-up with TCD every month after operation until TCD became normal, or up to seven months even if the TCD was still abnormal. SPSS 17.0 software was used to analyze the data.

RESULTS

In all 59 patients, there were 164 TCD-abnormal cerebral arteries. Among them, 37 patients(62.71%) with abnormal TCD arteries became normal within 1 to 7 months after operation, 8 patients (13.56 %) got better, but 14 patients (23.73 %) did not improve.

CONCLUSIONS

Abnormal blood flow of some cerebral arteries was possibly induced by increasing the activation of sympathetic nervous system around the vertebral arterial system, caused by chronic nasal obstruction. Nasal dilatancy surgery can improve the blood supplement of the cerebral arterial system.

Ultraviolet radiation and reactive oxygen generation as inducers of keratinocyte apoptosis: protective role of tea polyphenols

Ultraviolet A (UVA) radiation produces serious damage to skin, especially to dermis, but its damage to epidermis and responsible mechanisms are not fully understood. Studies were thus undertaken to investigate the effects of UVA or reactive oxygen species (ROS) on lipid peroxidation, cell cycle, and apoptosis in primary cultured rat keratinocytes and to determine the possible protective effects of tea polyphenols (TPP). UVA or ROS increased the release of plasma enzyme lactate dehydrogenase (LDH), and increased lipid peroxidation production (malondialdehyde, MDA), but decreased the activity of glutathione peroxidase (GSH-Px), indicating that UVA or ROS were cytostatic and peroxidizing to keratinocytes. TPP stabilized and protected cell membranes from ROS or UVA by inhibiting the release of LDH, lowering MDA levels, and increasing GSH-Px activity. Flow cytometry (FCM) analysis revealed that UVA or ROS decreased the proliferative index (PI); hence the cell growth was blocked in the S/G2 phase, with an increase in the percentage of apoptosis in primary keratinocytes. TPP modified the UVA or ROS-induced changes in PI and apoptosis. TPP may be useful to protect keratinocytes from UVA irradiation. In summary, these data demonstrated that UVA damage to skin keratinocytes in vitro was similar to that for ROS and that TPP protects against UVA-induced cytotoxicity by inhibiting lipid peroxidation and apoptosis.

The effects on cell growth of tea polyphenols acting as a strong anti-peroxidatant and an inhibitor of apoptosis in primary cultured rat skin cells

Studies during the past few years have indicated an inhibitory effect of green tea or tea polyphenols on tumorigenesis in animal and even in human. The purpose of this study was to observe the possible effects of tea polyphenols on skin cell growth and on apoptosis in rat primary cultured keratinocytes and fibroblasts. The release of a cell plasma enzyme (LDH), lipid peroxidation products (MDA production), and GSH-Px (glutathione peroxidase) into the medium in cultured cells was determined after treatment with tea polyphenols in a primary culture of skin cells. The percentage of cells in each cell cycle phase and in apoptosis were assayed by flow cytometry (FCM). Tea polyphenols may have a beneficial effect on skin cells at concentrations from 0.05% to 0.1%, showing a dose-dependent decrease in LDH, MDA (malondialdehyde) production, and a significant dose-dependent increase in GSH-Px and cell number. These effects were more obvious after exposure for 24 h than after 12 h. The results indicate that tea polyphenols may stabilize and protect the cell membrane against the release of cell plasma enzyme LDH, and its anti-peroxidation effect is also important for cell growth. FCM analysis revealed that treatment with 0.01% to 0.1% tea polyphenols decreased the percentage of cells in the G1/G0 (quiescent) phase from 81.32% to 74.38%, and increased the percentage of cells in S and G2/M phase from 9.87% to 15.26%, and from 6.51% to 10.36%, respectively. Tea polyphenols also increased the value of PI (proliferation index) from 18.17 to 25.62. At the same time it decreased the percentage of apoptosis from 27.10% to 17.97%, which indicates that green tea stimulates cell growth and inhibits the occurrence of apoptosis. Our results indicate that tea polyphenols are effective anti-oxidants and also inhibit apoptosis, which may improve the proliferative capacity of primary skin cells in vitro.

The secondary structure and architecture of human elastin

The presented work constitutes the first structural characterization of both insoluble human elastin and its solubilized form, kappa-elastin. Structural data were reached following the use of Fourier transform infrared, near infrared Fourier transform Raman and circular dichroism optical spectroscopic methods and their quantitative analysis permitted us to estimate approximately 10% alpha-helices, approximately 35% beta-strands and approximately 55% undefined conformations in the global secondary structure of insoluble human elastin in the solid state. Following the use of the LINK method, the probable local distribution of the secondary-structure elements along the sequence was determined and compared to that obtained for bovine elastin, the historical standard of elastin. This comparison led us to propose a globular architecture for the human elastomer and permitted us to delineate some elements of its structure-elasticity relationship.

Epitope specificity of monoclonal and polyclonal antibodies to human elastin

Polyclonal (pAb) and monoclonal (mAb) anti-human aorta elastin antibodies were reacted with a series of overlapping hexapeptides along the human tropoelastin sequence covering exons 2-7 and 23-36 from the N-terminus to the C-terminus, advancing 1 amino acid residue each time. ELISA indicated reactive epitopes. mAb A2.1 recognized sequences containing Ala-Lys, mAb G8.1, A7.1 and pAb, hydrophobic sequences. None of them reacted with the hexapeptide VGVAPG, or with desmosine or isodesmosine. pAb L85 reacted with a His-containing sequence coded in exon 26A. pAb kappaE(L), kappaE(S) and L85 reacted with the Cys-containing sequence of exon 36. A synthetic 14-residue peptide containing the three proximal tyrosines coded in exon 13 did not react with any of the antisera tested. It appears therefore that the most frequently recognized epitopes are hydrophobic sequences. One polyclonal antibody detected several isoforms of tropoelastin in the medium of cultured vascular smooth muscle cells. Monoclonal and polyclonal antibodies stained elastic fibers on tissue sections, suggesting that the epitopes recognized are available on the native fibers for reaction with the antibodies.

Relationship of serum elastin peptide level to single breath transfer factor for carbon monoxide in French coal miners

BACKGROUND

Clinical and epidemiological studies have given discordant results on the usefulness of the level of circulating elastin peptide (EP), a potential marker of both elastin destruction (a key phenomenon in pulmonary emphysema) and neosynthesis, for assessing structural changes in the lung extracellular matrix. The aim of the present study was to explore the relationship between levels of EP and forced expiratory volume in one second (FEV1) and single breath transfer factor for carbon monoxide (TLCO and KCO) in coal miners.

METHODS

The study population comprised 227 working coal miners aged 34-50 years consisting of 75 miners heavily exposed to underground coal dust with pulmonary radiographs classified as 0/1 or 1/0 by the International Labour Office classification, 75 exposed miners with radiographs classified as normal (0/0), and 77 miners slightly exposed to coal dust with normal radiographs. The subjects answered a standardised questionnaire and performed spirometric tests and a carbon monoxide (CO) transfer test.

RESULTS

No association was observed between EP levels and % predicted FEV1 (or FEV1/FVC). The level of EP increased significantly with decreased % predicted TLCO (r = -0.20). Miners in the lowest % predicted KCO quintile had higher EP levels than the rest (3.28 (1.37) vs 2.47 (1.16)). A significantly lower EP level was observed in miners with radiographs classified as 1/0 or 0/1, especially in those with round opacities, compared with miners with a normal radiograph, and in current smokers compared with the rest.

CONCLUSIONS

The results of this study suggest that the level of EP may reflect some remodelling activity in emphysema and lung fibrosis.

Elastin peptide concentration in human serum: variation with antibodies and elastin peptides used for the enzyme-linked immunosorbent assay

Discrepancies exist between the reported values for the mean elastin peptide (EP) concentration in human sera. In order to understand these discrepancies, several EP preparations were obtained in vitro and monoclonal and polyclonal antibodies were produced against them. These different EP preparations and antibodies were used in an enzyme-linked immunosorbent assay (ELISA) to study cross-reactivity between EP preparations and to quantitate EP concentration in human sera. The method of purification of elastin, the method of hydrolysis of elastin and the molecular weight of EP influence their reactivity with antibodies and the results of EP measurements in human sera. However, there is a good correlation between EP measurements carried out in several human sera with the different EP preparations and different antibodies. Although absolute values of the EP concentrations varied with the EP preparation and antibodies used for the ELISA, the variations of this EP concentration measured from one human serum to another are significant.

Protective effect of oleoyl peptide conjugates against elastolysis by neutrophil elastase and kappa elastin-induced monocyte chemotaxis

Elastin can impair the human neutrophil elastase (HNE) inhibitory capacity of elastase inhibitors. We synthesized oleoyl-alanyl-alanyl-prolyl-valine (Ol-Ala-Ala-Pro-Val-OH) (oleoyl peptide) and the amides (NH2 and NH-C3H7) of this peptide and studied their HNE-inhibitory potencies using succinyl-alanyl-alanyl-alanine-p-nitroanilide (Suc-Ala-Ala-Ala-pNA) or 3H-labeled elastin as substrates, as well as cryostat sections of rabbit skin as an ex vivo substrate. Using Suc-Ala-Ala-Ala-pNA, Ol-Ala-Ala-Pro-Val-OH had an IC50 of 3 microM. When the COOH terminal of the oleoyl peptide was derivatized to amide forms, the compound lost its ability to interact with HNE while keeping its elastin-protecting function: IC50 values for NH2 and NH-C3H7 derivatives were 22 and 17 microM, respectively. Also, the HNE-inhibitory capacity of Ol-Ala-Ala-Pro-Val-OH was only reduced 2-fold by using elastin as a substrate. This decrease was much lower than those determined with other HNE inhibitors of similar potency and could be accounted for by the ability of oleoyl peptide to bind to elastin. Cryostat sections of rabbit skin were also used as an ex vivo substrate for assessing the elastin-protecting property of Ol-Ala-Ala-Pro-Val-OH. Preincubating HNE and oleoyl peptide before application to tissue sections led to an IC50 of 8 microM, close to the value determined with elastin as a substrate. Treatment of sections with oleoyl peptide before adding HNE gave a lower IC50 (4 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Relation of serum elastin peptide concentration to age, FEV1, smoking habits, alcohol consumption, and protease inhibitor phenotype: an epidemiological study in working men

BACKGROUND

In clinical investigations elastin peptide concentration has been proposed as one potential marker of lung elastin degradation. No epidemiological study has yet confirmed this hypothesis.

METHODS

The relation of elastin peptide concentration to some factors closely related to pulmonary emphysema (age, smoking habits, FEV1 alpha protease inhibitor (PI) phenotype) and to alcohol consumption was examined in an epidemiological study of 310 working men. The elastin peptides used for obtaining antibodies and as reference in an ELISA assay were prepared from chemically hydrolysed elastin.

RESULTS

The elastin peptide concentration significantly decreased with age from 2.92 (1.54) micrograms/ml among subjects younger than 30 years to 2.18 (1.14) micrograms/ml among subjects older than 50. Elastin peptide concentration did not differ with smoking habits and was clearly unrelated to FEV1. A lower elastin peptide concentration was observed in all groups of subjects with a protease inhibitor phenotype other than PI MM (PI FM, IM, MP, MS, MZ, and S phenotypes).

CONCLUSIONS

The results cast doubts on the usefulness of the elastin peptide concentration as a marker of lung destruction in middle aged, predominantly healthy men. Blood elastin peptide concentration may reflect both elastin degradation and resynthesis. The results of this analysis suggest that several factors (age, alcohol consumption, non-PI MM phenotype) may be associated with decreased resynthesis of lung elastin. Further studies, conducted in various age groups and including estimates of the degree of lung destruction, are needed to unravel the mechanisms underlying lysis and resynthesis of lung elastin.

Predictions of the secondary structure and antigenicity of human and bovine tropoelastins

Secondary structure and antigenicity predictive methods have been applied to the sequences of human and bovine tropoelastins in order to have some insight into the molecular structure of its insoluble counterpart, i.e., elastin. For both tropoelastins, all the predictions yielded 11 major regions, in which the pleated conformation was predominant, separated by 10 strong helical segments of various lengths located within alanyl rich regions of the chains. The overall conformations of human and bovine tropoelastins were estimated to contain 18 +/- 5% alpha-helices, 63 +/- 17% beta-sheets, 13 +/- 13% beta-turns and 6 +/- 6% random coil. For both tropoelastins, antigenicity predictions indicated the presence of seven synthetic decapeptides corresponding to continuous linear epitopes of the molecule. Some of the predicted epitopes are located in the same regions in both species while others are not. These predictions have allowed us to propose an alpha/beta conformation for tropoelastin. Therefore this extracellular matrix macromolecule might be more structured (10 helical segments for about 18% of the overall structure) than previously suggested.

[Monoclonal antibody A12 against gastric cancer produced in immuno-reconstituted nude mice]

A monoclonal antibody (mAb) A12 against gastric cancer was prepared in immuno-reconstituted nude mice from human ductal adenocarcinoma of stomach, Sy86B. mAb A12 could react with the majority of gastric cancer tissues (24/27-88.9%) but only cross react with a few normal tissues tested. The corresponding antigen of mAb A12 (antigen A12) was expressed at higher levels and usually in more than 50% of the cancer cells. mAb A12 may be a valid preparation in targeting therapy of gastric cancer. Preliminary analysis of antigen A12 showed that it is a oncofetal antigen probably of glycolipid or glycoprotein in nature.

[Immunoelectron microscopic study on the localization of monoclonal antibodies on gastric cancer cells]

The localization of three monoclonal antibodies (mAb) against gastric cancer was studied on two human gastric cancer cell lines by immunoelectron microscopic technique. It was shown that the corresponding antigens of mAb 3G9 and 3H11 were distributed on the microvilli (M) and non-microvillous (NM) plasma membrane of target cells, with varying M to NM ratios depending on the mAbs and target cells used. However, the corresponding antigens of mAb, PD4 was only localized on the surface of round or finger-like bulges of target cells and never on the microvilli and non-microvillous plasma membrane. Since the nature and function of these tumor antigens are yet to be identified, the implication of the different distributions of these tumor antigens remains to be claifated.

Susceptibility of baboon aorta elastin to proteolysis

Elastin was purified from baboon aorta using Achromobacter collagenase and its susceptibility to proteolysis by various enzymes was studied. Human leukocyte elastase (HLE) hydrolysed baboon aortic elastin 8 times faster than human cathepsin G. Bovine chymotrypsin had virtually no activity against this substrate. The kinetic constants V and [S50] of aortic elastin hydrolysis by HLE (0.15 microM) were 0.00286 mg x ml-1 x min-1 and 0.158 mg x ml-1, respectively. One mg of this elastin could be saturated with 5.6 micrograms of HLE. As with elastins isolated from other sources, the hydrolysis of baboon aortic elastin by HLE was highly sensitive to ionic strength, and a biphasic effect was obtained with increasing NaCl concentrations. A nearly 2-fold stimulation of elastolysis was observed at a 0.15M NaCl concentration. Further increase in ionic strength led to a continuous decrease of the rate of elastolysis which paralleled the decrease of adsorption of elastase to baboon aortic elastin. Cathepsin G, but not bovine alpha-chymotrypsin, was able to stimulate the rate of hydrolysis of baboon aortic elastin by HLE. A 1.7 fold stimulation was observed for a 1:1 molar ratio of the two proteinases and rose to 2.1 for a HLE/Cat. G ratio equal to 8.

[Monoclonal antibodies against gastric cancer and their selective reaction on various tissues]

Spleen cells from Balb/c mice immunized in sequence with five human gastric cancer cell lines were fused with murine myeloma cell line SP2/0. Hybridomas 3F4, 3G9 and 3H11 secreting monoclonal antibodies (mAb) against gastric cancer were obtained through selective culture and screening. These mAb produced by the immunization procedure have good selectivity and high positive rate in reaction on gastric cancer. The positive rate of reaction on gastric cancer cells and tissues could reach 5/5 and 84.8-93.5%, respectively, whereas there was almost no positive reaction on normal cells and tissues As there was no correlation between the positive reaction of gastric cancer and their histopathologic typing, and the cross reaction of mAb with other tumors and fetal gastrointestinal tissues was quite high, the corresponding antigens of these mAb were considered as extensive oncofetal antigens.

[Expression of the surface antigen in human gastric cancer cells and the relation to cell cycles--correlated analysis with flow cytometry]

Expression of tumor-associated antigen in different gastric cancer cell lines and different phases of cell cycle was studied cytochemically. The antigen was recognized by the monoclonal antibody (McAb) PC1 against gastric cancer cells. By using the McAb PC1 as first antibody, the indirect immunofluorescence stain and the peroxidase-anti-peroxidase (PAP) stain were done on the gastric cancer cell lines (MGC 803, SGC 7901 and BGC 823). It was shown that PC1 antigen was mainly expressed on the membrane of these cells and only a certain percentage of the cells gave the positive reaction with different intensities. It was obvious that the expression of PC1 antigen was heterogeneous in nature. The heterogeneity of the PC1 antigen expression in gastric cancer cells might be due to either various subpopulations in the cell lines or different phases of cell cycle. In order to go further into the question, we studied quantitatively the expression of PC1 antigen in gastric cancer cell lines (MGC 803, STC 7901 and BGC 823) and the relationship between the antigen expression and cell cycle by double fluorescence stain and two-dimensional flow cytometry. It was found that expression levels of PC1 antigen in these cell lines were in the following order: MGC 803 greater than SGC 7901 greater than BGC 823. The PC1 antigen predominantly expressed on G1 phase for MGC 803 and G1, G2-M phase for SGC 7901 respectively. And uniform low level of PC1 antigen expression was found for BGC 823 throughout the cell cycle. Therefore, the PC1 antigen expression is dependent on cell cycle in MGC 803 and SGC 7901 cell lines.

[Gastric cancer-associated antigen P42]

The corresponding antigen to monoclonal antibody PCI against gastric cancer cells was demonstrated as a protein sensitive to heating and easily degraded by proteinase. By western blotting, it was shown that the molecular weight of the antigen was 42 KD and the antigen was named P42. P42 could be shed into serum-free culture medium of the target cells and its activity be assayed in sera of the gastric cancer patients. Using inhibition test, the levels of P42-like substance in sera were measured. The results indicated that this level in the gastric cancer patients (26.53 +/- 23.11) was markedly higher than that in patients with benign gastric diseases (4.66 +/- 2.67) and controls (2.57 +/- 2.67). It is suggested that P42, a novel gastric cancer-associated antigen, be useful in the mass screening and supplementary in diagnosing gastric cancer.