Advances in the study of gastric organoids as disease models

Gastric organoids are models created in the laboratory using stem cells and sophisticated three-dimensional cell culture techniques. These models have shown great promise in providing valuable insights into gastric physiology and advanced disease research. This review comprehensively summarizes and analyzes the research advances in culture methods and techniques for adult stem cells and induced pluripotent stem cell-derived organoids, and patient-derived organoids. The potential value of gastric organoids in studying the pathogenesis of stomach-related diseases and facilitating drug screening is initially discussed. The construction of gastric organoids involves several key steps, including cell extraction and culture, three-dimensional structure formation, and functional expression. Simulating the structure and function of the human stomach by disease modeling with gastric organoids provides a platform to study the mechanism of gastric cancer induction by Helicobacter pylori. In addition, in drug screening and development, gastric organoids can be used as a key tool to evaluate drug efficacy and toxicity in preclinical trials. They can also be used for precision medicine according to the specific conditions of patients with gastric cancer, to assess drug resistance, and to predict the possibility of adverse reactions. However, despite the impressive progress in the field of gastric organoids, there are still many unknowns that need to be addressed, especially in the field of regenerative medicine. Meanwhile, the reproducibility and consistency of organoid cultures are major challenges that must be overcome. These challenges have had a significant impact on the development of gastric organoids. Nonetheless, as technology continues to advance, we can foresee more comprehensive research in the construction of gastric organoids. Such research will provide better solutions for the treatment of stomach-related diseases and personalized medicine.

A mechanistic study of Anwei decoction intervention in a rat model of gastric intestinal metaplasia through the endoplasmic reticulum stress - Autophagy pathway

OBJECTIVE

To investigate the mechanism of Anwei decoction (AWD) intervention on gastric intestinal metaplasia (GIM) using a rat model through the endoplasmic reticulum stress-autophagy pathway.

METHODS

Gastric intestinal metaplasia was induced in rats using 1-methyl-3-nitro-1-nitrosoguanidine. The experiment included a normal control group, a model group, and low-, medium- and high-dose AWD groups. The specificity of intestinal epithelial cells was determined for model establishment and drug efficacy by detecting the protein expression of markers such as MUC2, VILLIN and CDX2 through western blotting (WB). The effects of AWD on endoplasmic reticulum stress and autophagy were evaluated by measuring the mRNA and protein expression levels of endoplasmic reticulum stress markers (PEPK, ATF6, CHOP and caspase-12) and autophagy markers (LC3Ⅱ and Beclin-1) using reverse transcription polymerase chain reaction and the WB method. Furthermore, the ultrastructure of gastric mucosal cells and autophagosome status were observed using transmission electron microscopy.

RESULTS

Compared with the model group, the AWD-treated rats exhibited significant improvement in body weight (P < 0.01), reduced protein expression of the intestine epithelial cell-specific markers MUC2, VILLIN, CDX2 and KLF4 (P < 0.01 for all) and increased SOX2 protein expression (P < 0.01). In addition, AWD suppressed the mRNA and protein expression of endoplasmic reticulum stress markers PEPK and ATF6 (P < 0.01 for all) and promoted the mRNA and protein expression of autophagy and apoptosis markers CHOP, caspase-12, LC3Ⅱ and Beclin-1 (P < 0.01 for all).

CONCLUSION

Anwei decoction effectively inhibits the further progression of GIM and prevents the occurrence of gastric mucosal carcinogenesis.

Limonitum Ameliorates Castor Oil-Induced Diarrhoea in Mice by Modulating Gut Microbiota

Diarrhoea is a common clinical condition; its pathogenesis is strongly associated with gut microbiota dysbiosis. Limonitum is a well-known traditional Chinese medicine that exerts appreciable benefits regarding the amelioration of diarrhoea. However, the mechanism through which Limonitum ameliorates diarrhoea remains unclear. Here, the efficacy and underlying mechanism of Limonitum decoction (LD) regarding diarrhoea were explored from the aspect of gut microbiota. Castor oil (CO) was used to induce diarrhoea in mice, which were then used to evaluate the effects of LD regarding the timing of the first defecation, diarrhoea stool rate, degree of diarrhoea, diarrhoea score, intestinal propulsive rate, and weight of intestinal contents. The concentrations of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric and valeric acids, were analysed by gas chromatography-mass spectrometry (GC-MS). The 16S rRNA high-throughput sequencing technology was applied to evaluate changes in the gut microbiota under exposure to LD. LD was found to effectively ameliorate the symptoms of diarrhoea, and the diversity and relative abundance of gut microbiota were restored to normal levels following LD treatment. Additionally, LD significantly restored the observed reductions in SCFAs. These results provide strong evidence that LD can sufficiently ameliorate diarrhoea in mice by regulating their gut microbiota. The findings presented here highlight that Limonitum may constitute a prospective remedy for diarrhoea.

[COVID-19 epidemic and its characteristics in Heilongjiang province]

Objective: To describe the COVID-19 epidemic and its characteristics in Heilongjiang province, and provide evidence for the further prevention and control of COVID-19 in the province. Methods: The information of COVID-19 cases and clusters were collected from national notifiable disease report system and management information system for reporting public health emergencies of China CDC. The Software's of Excel 2010 and SPSS 23.0 were applied for data cleaning and statistical analysis on the population, time and area distributions of COVID-19 cases. Results: On January 22, 2020, the first confirmed case of COVID-19 was reported in Heilongjiang. By March 11, 2020, a total of 482 cases domestic case of COVID-19, The incidence rate was 1.28/100 000, the mortality rate was 2.70% (13/482) in 13 municipalities in Heilongjiang. There were 81 clusters of COVID-19, The number of confirmed cases accounted for 79.25% (382/482) of the total confirmed cases and 12 cases of deaths. The family clusters accounted for 86.42% (70/81). Compared with the sporadic cases, the mortality rate, proportion of elderly cases aged 60 or above and severe or critical cases of clinical classification were all higher in the clusters especially the family clusters, but the differences were not significant (P>0.05). There were 34 clusters involving more than 5 confirmed cases accounted for 41.98% (34/81) of the total clusters, the involved cases accounted for 68.31% (261/382) of the total cases of clusters. There were significant differences in age distribution of the cases among the case clusters with different case numbers. In the clusters involving 6-9 cases, the proportion of cases aged 65 years or above was more (26.53%, 39/147). Conclusions: The incidence rate of COVID-19 was relatively high and the early epidemic was serious in Heilongjiang, The number of cases was large in clusters especially family clusters.

Ionization-induced adiabatic soliton compression in gas-filled hollow-core photonic crystal fibers

We investigate in the experiments the ionization-induced adiabatic soliton compression process in a short length of He-filled single-ring photonic crystal fiber. We observe that the plasma-driven blueshifting solitons show little residual light near the pump wavelength in a certain pulse energy region, leading to a high-efficiency frequency upconversion process. In contrast, at high pulse energy levels, we observe that the quality of the frequency upshifting process is impaired due to the existence of a dynamical loss channel induced by the coupling of the soliton to linear modes near the pump wavelength. In addition, through adjusting the input pulse energy, the central wavelength of blueshifting solitons can be continuously tuned over 300 nm. These experimental results, confirmed by numerical simulations, not only offer a deep insight into ionization-induced soliton-plasma dynamics in gas-filled hollow-core photonic crystal fibers, but also develop highly tunable ultrafast light sources at visible wavelengths, which may have many applications in ultrafast spectroscopy.

Effect of gene polymorphims on the warfarin treatment at initial stage

The adverse reactions of warfarin that were found mainly occurred in the first month. This study was carried out to observe the effect of gene polymorphisms on the warfarin therapy at the initial stage. Four-hundred and sixty Chinese patients began warfarin treatment with daily 2.5 mg after heart valve replacement operations were enrolled. The daily international normalized ratio (INR) for anticoagulation were recorded till the seventh day. Blood samples were collected and used to detect genotypes for VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650. INR and their changes were compared among genotypes. INR was partially correlated with the VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 polymorphisms from the third, fourth and sixth day on, respectively. VKORC1 rs7294 and CYP4F2 rs2108622 carriers responded lower than the wild genotype, whereas CYP2C9 rs1057910 and ORM1 rs17650 carriers responded higher, respectively. Fifty percent of AA/*1*3/CC/*S*S patients and 16% of AA/*1*1/CC/*S*S patients were over anticoagulation treated with INR >4.0 at the third day. Ninety percent of VKORC1 rs7294 carrier patients have INR <1.63, a mark of the 25% of lower responders of the wild genotype. Our study provided another kind of evidence that VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 affected the action of warfarin in different styles. Patients with AA/*1*1/CC/*S*S, AA/*1*3/CC/*S*S should use a less initial dosage to avoid over anticoagulation, and patients with VKORC1 rs7294 should use larger initial dose to proof an effective therapy.

Effect of Anwei decoction on expression of P21ras and P53 in malignant ulcers in rats

AIM: To investigate the effect of Anwei decoction on P21ras and P53 protein expression in experimental malignant ulcers in a rat model.

METHODS: Seventy-two rats were randomly divided into a blank control group, a model control groups, high-, medium- and low-dose Anwei decoction group, and a Weifuchun group. Malignant ulcers were induced in rats by applying acetic acid to gastric mucosal surface. Immunohistochemistry was used for detection of P21ras and P53 protein expression.

RESULTS: Compared with the model control group, P21ras expression levels were significantly decreased in the Anwei decoction groups and Weifuchun group (P < 0.05). P21ras expression levels in ulcer tissue differed significantly between the medium Anwei decoction group and the Weifuchun group (P < 0.05). Compared with the model control group, P53 expression levels were significantly increased in the high-dose Anwei decoction group and Weifuchun group (P < 0.05). Obvious ulcer healing was noted in Anwei decoction groups.

CONCLUSION: Anwei decoction has a significant effect on the expression of P21ras and P53 in malignant ulcers in rats, and this may be one of mechanisms underlying the therapeutic effect of Anwei decoction against canceration of malignant ulcers.

Changes in levels of GAS, CCK, and SS in serum and gastric tissue of spleen deficiency rats: Effect of traditional Chinese medicine intervention

AIM: To investigate the changes in levels of gastrin (GAS), cholecystokinin (CCK), somatostatin (SS) in serum and gastric tissue of spleen deficiency rats and the effect of traditional Chinese medicine intervention.

METHODS: Thirty-six SD rats were randomly divided into three groups by random number table method. Twelve rats were fed distilled water as a control group, and 24 rats were used to induce spleen deficiency (chronic restraint stress + excess fatigue + eating disorders). Twelve spleen deficiency rats were used as an observation group, and the other 12 spleen deficiency rats fed Sijunzi decoction for 7 d as a treatment group. Levels of GAS, CCK, and SS in serum and gastric tissue were detected by ELISA.

RESULTS: The levels of GAS, CCK, and SS in serum and GAS in gastric tissue were significantly lower in the observation group than in the control group, while CCK and SS in gastric tissue were significantly higher than those in the control group (P < 0.05). GAS, CCK, and SS in serum and GAS in gastric tissue were significantly higher in the treatment group than in the observation group, while CCK and SS in gastric tissue were significantly lower than those in the observation group (P < 0.05).

CONCLUSION: Gastrointestinal hormones GAS, CCK, and SS in serum and gastric tissue of spleen deficiency rats show abnormal changes. Traditional Chinese medicine intervention can effectively correct abnormal fluctuations of GAS, CCK, and SS.

Chemical correlation between Gegen Qinlian dispensing granule and its four raw herbs by LC fingerprint

Gegen Qinlian dispensing granule, a favorite composite formula, is a combination of Radix Puerariae Lobatae, Radix Scutellariae, Rhizoma Coptidis and Radix et Rhizoma Glycyrrhizae Praeparata cum Melle. To develop a method to overall evaluate correlation between the formula and its four raw herbs, LC fingerprints of the formula and its raw herbs were developed and LC-DAD-MS was employed to identify the components in the formula fingerprint. According to the characteristic fragmentation behavior of known flavonoids, alkaloids and saponins isolated from the four raw herbs as well as retention time, UV and MS data of detected compounds, a total of 23 constituents in the formula fingerprint were structurally characterized. Chemical correlation between the formula and the four crude herbs was evaluated qualitatively and quantitatively by the developed LC fingerprints. The results showed that 8 components in the formula fingerprint were addressed to Radix Puerariae Lobatae, 11 to Radix Scutellariae, 7 to Rhizoma Coptidis, 3 to Radix et Rhizoma Glycyrrhizae Praeparata cum Melle, and that the relative area ratios of the common peaks in the formula vary slightly in comparison with corresponding ratios in its crude herbs, demonstrating the chemical constituents in the formula have patterns similar to those in its crude herbs.

External beam radiation therapy for inoperable hepatocellular carcinoma with portal vein thrombosis

Portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC) has a poor impact on prognosis. Many of these tumors may cause intrahepatic and extrahepatic metastases. From January 1991 to December 1996, 41 unresectable HCC patients with PVT underwent transcatheter arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) to the portion of PVT. The irradiated field, with a mean equivalent field size of 6.6 x 7.1 cm2, was localized and simulated by abdominal sonography, angiography and computed tomography. Radiation dose ranged from 36 to 66 Gy (mean dose: 51.4 Gy), in a daily fraction of 1.8 to 2 Gy. The response of EBRT was evaluated by abdominal sonography within 3 months of completion of EBRT. The response rates of the PVT after treatment were 39% for complete response (CR), 41% for partial response (PR), and 19% for no response (NR), respectively. The median overall survival time from start of radiotherapy was 10 months for all patients, 17 months for CR patients, 8 months for PR patients and 4 months for NR patients. By multivariate analysis, response of PVT resulted in a significant improvement in survival. (P = 0.001) There was no occurrence of severe complication of radiation-induced liver disease. The results obtained with combined treatment modality of EBRT and TACE in the treatment of HCC patients with PVT are encouraging.

Targeted disruption of mouse Pds provides insight about the inner-ear defects encountered in Pendred syndrome

Following the positional cloning of PDS, the gene mutated in the deafness/goitre disorder Pendred syndrome (PS), numerous studies have focused on defining the role of PDS in deafness and PS as well as elucidating the function of the PDS-encoded protein (pendrin). To facilitate these efforts and to provide a system for more detailed study of the inner-ear defects that occur in the absence of pendrin, we have generated a Pds-knockout mouse. Pds(-/-) mice are completely deaf and also display signs of vestibular dysfunction. The inner ears of these mice appear to develop normally until embryonic day 15, after which time severe endolymphatic dilatation occurs, reminiscent of that seen radiologically in deaf individuals with PDS mutations. Additionally, in the second postnatal week, severe degeneration of sensory cells and malformation of otoconia and otoconial membranes occur, as revealed by scanning electron and fluorescence confocal microscopy. The ultrastructural defects seen in the Pds(-/-) mice provide important clues about the mechanisms responsible for the inner-ear pathology associated with PDS mutations.

Mutations in the gene encoding tight junction claudin-14 cause autosomal recessive deafness DFNB29

Tight junctions in the cochlear duct are thought to compartmentalize endolymph and provide structural support for the auditory neuroepithelium. The claudin family of genes is known to express protein components of tight junctions in other tissues. The essential function of one of these claudins in the inner ear was established by identifying mutations in CLDN14 that cause nonsyndromic recessive deafness DFNB29 in two large consanguineous Pakistani families. In situ hybridization and immunofluorescence studies demonstrated mouse claudin-14 expression in the sensory epithelium of the organ of Corti.

Patterning of the mammalian cochlea

The mammalian cochlea is sophisticated in its function and highly organized in its structure. Although the anatomy of this sense organ has been well documented, the molecular mechanisms underlying its development have remained elusive. Information generated from mutant and knockout mice in recent years has increased our understanding of cochlear development and physiology. This article discusses factors important for the development of the inner ear and summarizes cochlear phenotypes of mutant and knockout mice, particularly Otx and Otx2. We also present data on gross development of the mouse cochlea.

Sensory organ generation in the chicken inner ear: contributions of bone morphogenetic protein 4, serrate1, and lunatic fringe

The chicken inner ear is a remarkably complex structure consisting of eight morphologically distinct sensory organs. Unraveling how these sensory organs are specified during development is key to understanding how such a complex structure is generated. Previously, we have shown that each sensory organ in the chicken inner ear arises independently in the rudimentary otocyst based on Bone morphogenetic protein 4 (Bmp4) expression. Here, we compare the expression of Bmp4 with two other putative sensory organ markers, Lunatic Fringe (L-fng) and chicken Serrate1 (Ser1), both of which are components of the Notch signaling pathway. L-fng and Ser1 expression domains were asymmetrically distributed in the otic cup. At this early stage, expression of L-fng is similar to Delta1 (Dl1), in an anteroventral domain apparently corresponding to the neurogenic region, while Ser1 is expressed at both the anterior and posterior poles. By the otocyst stage, the expression of both L-fng and Ser1 largely coincided in the medial region. All presumptive sensory organs, as identified by Bmp4 expression, arose within the broad L-fng- and Ser1-positive domain, indicating the existence of a sensory-competent region in the rudimentary otocyst. In addition, there is a qualitative difference in the levels of expression between L-fng and Ser1 such that L-fng expression was stronger in the ventral anterior, whereas Ser1 was stronger in the dorsal posterior region of this broad domain. This early difference in expression may presage the differences among sensory organs as they arise from this sensory competent zone.

Ectopic noggin blocks sensory and nonsensory organ morphogenesis in the chicken inner ear

Bone morphogenetic protein 4 (Bmp4) is expressed during multiple stages of development of the chicken inner ear. At the otocyst stage, Bmp4 is expressed in each presumptive sensory organ, as well as in the mesenchymal cells surrounding the region of the otocyst that is destined to form the semicircular canals. After the formation of the gross anatomy of the inner ear, Bmp4 expression persists in some sensory organs and restricted domains of the semicircular canals. To address the role of this gene in inner ear development, we blocked BMP4 function(s) by delivering one of its antagonists, Noggin, to the developing inner ear in ovo. Exogenous Noggin was delivered to the developing otocyst by using a replication-competent avian retrovirus encoding the Noggin cDNA (RCAS-N) or implanting beads coated with Noggin protein. Noggin treatment resulted in a variety of phenotypes involving both sensory and nonsensory components of the inner ear. Among the nonsensory structures, the semicircular canals were the most sensitive and the endolymphatic duct and sac most resistant to exogenous Noggin. Noggin affected the proliferation of the primordial canal outpouch, as well as the continual outgrowth of the canal after its formation. In addition, Noggin affected the structural patterning of the cristae, possibly via a decrease of Msx1 and p75NGFR expression. These results suggest that BMP4 and possibly other BMPs are required for multiple phases of inner ear development.

Characterization and expression of sema4g, a novel member of the semaphorin gene family

Semaphorins constitute a large and growing gene family, several members of which are axon guidance molecules. We report the characterization of sema4g, a novel class IV member of the semaphorin gene family, located on mouse chromosome 19. sema4g is expressed early in development in the brain, spinal cord, and several sensory organs as well as specific populations of projection neurons, compatible with the well-established function of semaphorins as axon guidance molecules.

Expression pattern of the mouse ortholog of the Pendred's syndrome gene (Pds) suggests a key role for pendrin in the inner ear

Pendred's syndrome is an autosomal-recessive disorder characterized by deafness and goiter. After our recent identification of the human gene mutated in Pendred's syndrome (PDS), we sought to investigate in greater detail the expression of the gene and the function of its encoded protein (pendrin). Toward that end, we isolated the corresponding mouse ortholog (Pds) and performed RNA in situ hybridization on mouse inner ears (from 8 days postcoitum to postnatal day 5) to establish the expression pattern of Pds in the developing auditory and vestibular systems. Pds expression was detected throughout the endolymphatic duct and sac, in distinct areas of the utricle and saccule, and in the external sulcus region within the cochlea. This highly discrete expression pattern is unlike that of any other known gene and involves several regions thought to be important for endolymphatic fluid resorption in the inner ear, consistent with the putative functioning of pendrin as an anion transporter. These studies provide key first steps toward defining the precise role of pendrin in inner ear development and elucidating the pathogenic mechanism for the deafness seen in Pendred's syndrome.

Otx1 and Otx2 activities are required for the normal development of the mouse inner ear

The Otx1 and Otx2 genes are two murine orthologues of the Orthodenticle (Otd) gene in Drosophila. In the developing mouse embryo, both Otx genes are expressed in the rostral head region and in certain sense organs such as the inner ear. Previous studies have shown that mice lacking Otx1 display abnormal patterning of the brain, whereas embryos lacking Otx2 develop without heads. In this study, we examined, at different developmental stages, the inner ears of mice lacking both Otx1 and Otx2 genes. In wild-type inner ears, Otx1, but not Otx2, was expressed in the lateral canal and ampulla, as well as part of the utricle. Ventral to the mid-level of the presumptive utricle, Otx1 and Otx2 were co-expressed, in regions such as the saccule and cochlea. Paint-filled membranous labyrinths of Otx1−/− mutants showed an absence of the lateral semicircular canal, lateral ampulla, utriculosaccular duct and cochleosaccular duct, and a poorly defined hook (the proximal part) of the cochlea. Defects in the shape of the saccule and cochlea were variable in Otx1−/− mice and were much more severe in an Otx1−/−;Otx2(+/)- background. Histological and in situ hybridization experiments of both Otx1−/− and Otx1−/−;Otx2(+/)- mutants revealed that the lateral crista was absent. In addition, the maculae of the utricle and saccule were partially fused. In mutant mice in which both copies of the Otx1 gene were replaced with a human Otx2 cDNA (hOtx2(1)/ hOtx2(1)), most of the defects associated with Otx1−/− mutants were rescued. However, within the inner ear, hOtx2 expression failed to rescue the lateral canal and ampulla phenotypes, and only variable rescues were observed in regions where both Otx1 and Otx2 are normally expressed. These results suggest that both Otx genes play important and differing roles in the morphogenesis of the mouse inner ear and the development of its sensory organs.

Imaging features of simultaneous occurrence of renal and pancreatic foreign body granuloma due to chronically retained gauze: a case report

Herein we are reporting a case of simultaneous occurrence of renal and pancreatic foreign body granuloma due to retained gauze. The different imaging features of the two lesions make correct preoperative diagnosis difficult. Foreign body granulomas due to retained surgical gauze or sponges should be considered in patients who have previous histories of operations and who also have a mass in the surgical bed. Simultaneous occurrence of foreign body granuloma away from primary surgical field is also possible.

Mutations in the gene encoding B1 subunit of H+-ATPase cause renal tubular acidosis with sensorineural deafness

H+-ATPases are ubiquitous in nature; V-ATPases pump protons against an electrochemical gradient, whereas F-ATPases reverse the process, synthesizing ATP. We demonstrate here that mutations in ATP6B1, encoding the B-subunit of the apical proton pump mediating distal nephron acid secretion, cause distal renal tubular acidosis, a condition characterized by impaired renal acid secretion resulting in metabolic acidosis. Patients with ATP6B1 mutations also have sensorineural hearing loss; consistent with this finding, we demonstrate expression of ATP6B1 in cochlea and endolymphatic sac. Our data, together with the known requirement for active proton secretion to maintain proper endolymph pH, implicate ATP6B1 in endolymph pH homeostasis and in normal auditory function. ATP6B1 is the first member of the H+-ATPase gene family in which mutations are shown to cause human disease.

The differential sensitivities of inner ear structures to retinoic acid during development

In order to examine the mechanisms that underlie development of the inner ear, the normal processes were perturbed using all-trans-retinoic acid (RA). By implanting a resin exchange bead saturated with RA into stage 16 (Hamburger and Hamilton, 1951, J. Morphol. 88, 49-92) embryonic day 2.5 chick ears, it was possible to analyze its in vivo effects on inner ear development. There is a temporal window during which the developing chick inner ear is particularly susceptible to the effects of RA (stages 16-19). This RA period of sensitivity precedes evidence of gross morphologic or histologic differentiation by at least 24 h, suggesting that mechanisms controlling formation of key inner ear structures are already in progress. There is a dose dependence on RA, with increasing doses of RA generating increasingly severe phenotypic abnormalities. Data indicate that these effects are due to differential sensitivities of the various inner ear structures to RA during their formation. In general, the vestibular structures were more susceptible to RA effects than the cochlear duct. Furthermore, nonsensory structures such as semicircular canals seemed to display a greater susceptibility to RA than their associated sensory structures (i.e., cristae). Among the three semicircular canals, the superior canal was the most susceptible to RA treatment, whereas the common crus was particularly resistant, suggesting that the molecular mechanisms for each structure's formation are different. The defect in semicircular canal formation is due to problems in the initial outgrowth of the canal plate which in turn is related to a down-regulation of early otocyst cell proliferation. This perturbation model provides valuable insight into the processes involved in producing the intricate patterning of the inner ear.

Inflammatory/infectious diseases and neoplasms of colon. Evaluation with CT

The purpose of this study is to review the computed tomography (CT) appearance of infectious and inflammatory diseases, and neoplasms of colon. Forty-five patients with 25 cases of colonic neoplasms and 20 cases of inflammatory and infectious diseases of colon were evaluated based on CT findings of colonic wall thickening (> 5 mm, soft tissue density versus pure wall edema or both), length of the involved segment (short (< or = 5 cm) versus long segment), pericolic infiltration, mesenteric infiltration, lateroconal fascial thickening, mechanical ileus, ascites, contiguous terminal ileum involvement, distribution of the diseased colon, and abscess formation. The results were compared using chi-square test or Fisher's exact test. Our results showed that colonic wall thickening of soft tissue density with or without edema and pure bowel wall edema were the two statistically significant findings in differential diagnosis of colon (p < 0.05). We concluded that CT is a good imaging tool to make differential diagnosis between infectious/ inflammatory diseases and neoplasms.

Development of the mouse inner ear and origin of its sensory organs

The molecular mechanisms dictating the morphogenesis and differentiation of the mammalian inner ear are largely unknown. To better elucidate the normal development of this organ, two approaches were taken. First, the membranous labyrinths of mouse inner ears ranging from 10.25 to 17 d postcoitum (dpc) were filled with paint to reveal their gross development. Particular attention was focused on the developing utricle, saccule, and cochlea. Second, we used bone morphogenetic protein 4 (BMP4) and lunatic fringe (Fng) as molecular markers to identify the origin of the sensory structures. Our data showed that BMP4 was an early marker for the superior, lateral, and posterior cristae, whereas Fng served as an early marker for the macula utriculi, macula sacculi, and the sensory portion of the cochlea. The posterior crista was the first organ to appear at 11.5 dpc and was followed by the superior crista, the lateral crista, and the macula utriculi at 12 dpc. The macula sacculi and the cochlea were present at 12 dpc but became distinguishable from each other by 13 dpc. Based on the gene expression patterns, the anterior and lateral cristae may share a common origin. Similarly, three sensory organs, the macula utriculi, macula sacculi, and cochlea, seem to arise from a single region of the otocyst.

Evaluation of galactography for nipple discharge

Galactography is useful in the evaluation of spontaneous discharge from the nipple of a nonlactating breast. Without galactography, surgeons have relied on either masectomy or excision of the major duct system responsible for the discharge. From January 1989 to May 1996, 106 galactograms were performed with monofilament polypropylene suture guiding for duct cannulation in 105 cases. The discharge duct was identified by pre-operative galactography, followed by a selective excision of ductal-lobular unit. In all tissue specimens, the cause of the pathologic secretion was found histologically; most often, it was intraductal papilloma (42.6%). In 35.6% of the specimens, findings with a prospective significance (papillomatosis, hyperplasia, carcinoma) were discovered and further operative treatment was initiated. The color of the discharge allowed no prediction of the histological findings. The accuracy of galactography was 88.4%, 84.6%, and 77.4% in papilloma, cancer, and other benign lesions, respectively. It is better than physical examination and other tests. Galactography represents a useful test in the diagnostic workup of secretory breasts.

Tear of the anterior cruciate ligament: evaluation with MR imaging

Sixteen patients with traumatic injury to the knees were surveyed with magnetic resonance (MR) machines with field strength of either 0.5 Tesla (T) using head coil (10 cases) or 1.5 T using dedicated knee coil (6 cases). Tears of the anterior cruciate ligament (ACL) were found in eight cases. The other eight cases had injuries of the other ligaments, meniscus or bone with intact ACL. All cases were proved by arthroscopy. Primary and secondary signs of the ACL tears were evaluated by MR imaging. Primary signs included the status of ACL. Secondary signs consisted of bone bruise in the posterolateral tibial plateau, in the lateral femoral condyle, or both (so-called kissing bone bruise), fracture at the posterolateral tibial plateau, Segond fracture, anterior dislocation of the tibia (> 5 mm), buckled posterior cruciate ligament (PCL), positive PCL line and the deep lateral femoral notch (> 1.5 mm). Of the eight cases of the ACL tears, 5 cases (62.5%) revealed thickening and edema of the ACL, 3 cases (37.5%) kissing bone bruise, 1 case (12.5%) Segond fracture, 2 cases (25%) buckled PCL, 2 cases (25%) deep lateral femoral notch, 2 cases (25%) anterior dislocation of the tibia and 0 case (0%) positive PCL line. The ACL had normal thickness of low signal intensity in 3 cases of chronic ACL tears (50%). Lateral meniscal tears were found in seven of the eight cases of ACL tears (87.5%). For the eight cases with intact ACL, the ACL was normal in thickness and of low signal intensity. Other findings were bone bruise in the lateral femoral condyle (1 case, 12.5%), fracture at the posterolateral tibial plateau (1 case, 12.5%), buckled PCL (1 case, 12.5%) and positive PCL line (1 case, 12.5%). It is concluded that primary sign is important in the MR diagnosis of the ACL tears. Secondary signs are helpful but may be present in lesions with intact ACL.

Axial specification for sensory organs versus non-sensory structures of the chicken inner ear

A mature inner ear is a complex labyrinth containing multiple sensory organs and nonsensory structures in a fixed configuration. Any perturbation in the structure of the labyrinth will undoubtedly lead to functional deficits. Therefore, it is important to understand molecularly how and when the position of each inner ear component is determined during development. To address this issue, each axis of the otocyst (embryonic day 2.5, E2.5, stage 16–17) was changed systematically at an age when axial information of the inner ear is predicted to be fixed based on gene expression patterns. Transplanted inner ears were analyzed at E4.5 for gene expression of BMP4 (bone morphogenetic protein), SOHo-1 (sensory organ homeobox-1), Otx1 (cognate of Drosophila orthodenticle gene), p75NGFR (nerve growth factor receptor) and Msx1 (muscle segment homeobox), or at E9 for their gross anatomy and sensory organ formation. Our results showed that axial specification in the chick inner ear occurs later than expected and patterning of sensory organs in the inner ear was first specified along the anterior/posterior (A/P) axis, followed by the dorsal/ventral (D/V) axis. Whereas the A/P axis of the sensory organs was fixed at the time of transplantation, the A/P axis for most non-sensory structures was not and was able to be re-specified according to the new axial information from the host. The D/V axis for the inner ear was not fixed at the time of transplantation. The asynchronous specification of the A/P and D/V axes of the chick inner ear suggests that sensory organ formation is a multi-step phenomenon, rather than a single inductive event.

The expression domain of two related homeobox genes defines a compartment in the chicken inner ear that may be involved in semicircular canal formation

Homeobox-containing genes encode a class of proteins that control patterning in developing systems, in some cases by acting as selector genes that define compartment identity. In an effort to demonstrate a similar role for such genes during ear development in the chicken, we present a detailed expression study of two related homeobox-containing genes, SOHo-1 and GH6, using in situ hybridization. At otocyst stages the two genes define a broad lateral domain of expression, which may represent a developmental compartment. Three-dimensional computer reconstructions of SOHo-1 expression at these and later stages revealed that the lateral domain becomes progressively restricted to the three semicircular canals. Thus, SOHo-1 and GH6 are among a small group of markers for a specific structural component of the inner ear. The gene expression domain initially includes the sensory regions of the semicircular canals, known as the cristae ampullaris, but none of the other four sensory organs which were recognizable by BMP4 expression during early morphogenesis (stages 19-24). Significantly, two of the sensory organs (the superior and posterior cristae) were found at the limits, or boundaries, of the SOHo-1/GH6 expression domain, suggesting that compartment boundaries may be involved in specifying sensory organ location as well as identity. Maintained expression at the boundaries may aid in specifying the location of canal outgrowth. These concepts are presented as a formal model which emphasizes that patterning information could be provided at the boundaries of gene expression domains in the inner ear.

Control of dopamine release in the retina: a transgenic approach to neural networks

Dopaminergic, interplexiform amacrines (DA cells) were labeled in transgenic mice with human placental alkaline phosphatase, an enzyme that resides on the outer surface of the cell membrane. It was therefore possible to investigate their activity in vitro after dissociation of the retina with whole-cell current and voltage clamp, as well as their connections in the intact retina with the electron microscope. DA cells generate action potentials even in the absence of synaptic inputs. This activity is abolished by the amacrine cell transmitters GABA and glycine, which induce an inward current carried by chloride ions, and is stimulated by kainate, an agonist at the receptor for the bipolar cell transmitter glutamate, which opens nonselective cation channels. Since DA cells are postsynaptic to amacrine and bipolar cells, we suggest that the spontaneous discharge of DA cells is inhibited in the dark by GABAergic amacrines that receive their input from off-bipolars. Upon illumination, the GABA-inhibition is removed, DA cells generate action potentials, and their firing is modulated by the excitation received from on-bipolars.

Differential expression of bone morphogenetic proteins in the developing vestibular and auditory sensory organs

The genes responsible for the formation of various sensory organs in the inner ear are not known. There are eight sensory organs in the chick inner ear, and our previous study showed that all presumptive sensory organs initially express bone morphogenetic protein 4 (BMP4), a member of the transforming growth factor (TGF)-beta gene family. To address the potential role of BMPs in the patterning of different sensory organ structures, we investigated the expression of BMP4, BMP5, and BMP7 during sensory organ differentiation in the chick inner ear. The gene expression pattern of BMP5, although similar to that of BMP4, was transient and disappeared by embryonic day 3.5 (E3.5). In contrast, BMP7 gene expression was quite extensive, starting in the otic placode. By E5, gene expression patterns of BMP4 and BMP7 differed among vestibular and auditory sensory organs. In the vestibular sensory organs, BMP7 gene expression segregated from the main sensory tissue areas at the onset of differentiation, whereas BMP4 expression concentrated in supporting cells. In the cochlea, however, BMP7 gene expression became restricted to sensory tissue over time and eventually concentrated in supporting cells, whereas BMP4 gene expression was localized to hair cells. The different BMP expression patterns in developing auditory and vestibular sensory organs may help to shape each respective sensory structure. Furthermore, the expression of BMP4 in the cochlea also revealed an interesting pattern of sensory cell differentiation: the distal portion of the cochlea differentiates first, and the tall hair cells develop before the short hair cells.

Sensory organ generation in the chick inner ear

There are a total of eight sensory organs in the chick inner ear. Each sensory organ has a distinct structure tailored for its function, and its morphology is well characterized. However, the origin of these sensory organs and the lineage relationships among them are largely unknown. In this report, we show that BMP4 (bone morphogenetic protein), a secreted protein of the TGF-beta gene family, is the earliest sensory marker identified to date for the chick inner ear. In addition to BMP4, we show that Msx-1 is a sensory marker for the three cristae, the lagena, and macula neglecta. P75NGFR (nerve growth factor receptor) is a marker for the three cristae only. Based on the expression pattern of these three genes-BMP4, Msx-1, and p75NGFR-it is estimated that the first sensory organs to be generated were the superior and posterior cristae at stage 19, followed by the macula sacculi at stage 20, the lateral crista at stage 22, the basilar papilla and lagena at stage 23, the macula utriculi at stage 24, and the macula neglecta at stage 29. The age of generation of each sensory organ as defined by the first appearance of these molecular markers is well in advance of the histological differentiation. In addition, the differential gene expressions in each presumptive sensory organ may contribute to the distinct structure of the mature organ.

Mandibular arteriovenous malformation diagnosed by MR and MRA: a case report

A case of mandibular arteriovenous malformation (AVM) is presented. Prompt diagnosis and appropriate management are essential due to massive bleeding or even death after dental extraction or biopsy. Angiography remains the gold standard in detecting the lesion. Magnetic resonance (MR) imaging with spin-echo sequences reveals the vascular malformation as signal-void. MR angiography can demonstrate the nidus, dilated artery and vein. MR imaging and MR angiography can supplement angiography in the diagnosis of mandibular AVM.

The stability of endogenous tyrosine hydroxylase protein in PC-12 cells differs from that expressed in mouse fibroblasts by gene transfer

Previous studies have used recombinant retroviruses encoding the tyrosine hydroxylase (TH) gene to transduce various cell lines, including fibroblasts (NIH-3T3), a pituitary tumor cell line (AtT20), and a pancreatic endocrine line (RIN). These genetically modified cells, synthesizing either 3,4-dihydroxyphenylalanine, dopamine, or both, are potential donors for treatment of Parkinson's disease. However, the levels of TH protein in such transduced cells have been low and heterogeneous. Using several modified versions of retrovirus vectors encoding TH, we demonstrated that protein stability is an important factor governing levels of TH in NIH-3T3 fibroblasts. Whereas low levels of TH protein were observed in infected NIH-3T3 cells, high levels of a TH-beta gal fusion protein were found. This difference was due to a significantly longer half-life of the TH-beta gal fusion protein relative to TH alone. However, the TH-beta gal fusion protein was found to be enzymatically inactive. We also found that the half-life of the endogenous TH protein in PC-12 cells is sevenfold longer than the TH protein in transduced fibroblasts, implying that a cell-type specific regulator or mechanism may stabilize TH in catecholaminergic cells.

Reappraisal of gastroduodenal lesions after transcatheter arterial chemoembolization of liver neoplasms--selective versus superselective method

Twenty-six patients with liver neoplasm receiving transcatheter arterial chemoembolization (TAE) therapy underwent gastroduodenal endoscopic examinations before and after TAE. The balloon was inflated in the common hepatic artery before chemoembolization if superselective cannulation beyond the gastroduodenal artery could not be done. Sixteen of the 26 patients (61.5%) showed new gastroduodenal lesions, with superficial gastritis in six, one or more erosions in nine, and hemorrhagic gastritis in five. The frequency of lesions detected was no different when the common hepatic artery was obstructed (60.0%) than when superselective embolization was done in more peripheral branch(es) (60.0%). No clinical events indicating upper gastrointestinal bleeding were noticed after TAE. The presence of esophageal and/or gastric varices and session(s) of TAE performed before did not affect the occurrence of gastroduodenal lesion(s). We conclude that TAE produces erosive gastroduodenal lesions that are detected by endoscopic examination but are clinically unimportant; balloon catheter occlusion of the common hepatic artery did not result in more frequent gastroduodenal complications than the ordinary superselective chemoembolization method.

Development of dopaminergic neurons is insensitive to optic nerve section in the neonatal rat retina

The development of tyrosine-hydroxylase-immunoreactive (TH-IR) cells was studied in pre- and postnatal rat retinas. Using a modified staining method, TH-IR cells were first detectable in retinal wholemounts at embryonic day 19 (E19), much earlier than previously reported. By E20, TH-IR cells were present in every retina examined. These 'early' TH-IR cells were always concentrated at the peripheral dorsal part of the retina, in contrast to the expected distribution predicted by the center to peripheral gradient of retinal development. The development of TH-IR cells and their pattern of distribution were insensitive to optic nerve section, indicating that the postnatal development of dopaminergic neurons is independent of the presence of ganglion cells.

[Effects of PGE1 on penile blood flow]

From February to July in 1989, 47 patients came to our O.P.D. with the chief complaint of impotence. The average age was 48.3 +/- 10.7 y/o. We applied intracoporeal injection of prostaglandin PGE1 (20 mg); and evaluated its penile blood flow effect by color duplex scanning (Acuson 128). The erectile responses of the test showed that: 6 patients (12.8%) had normal response: and 16 patients (34%) had imperfect response. Altogether, the total positive response rate was 46.8%, and 25 patients (53.2%) showed impaired response. The onset of response was 9.1 +/- 3.6 minutes and the duration of erection was 59.2 +/- 24.7 minutes. The percentage of diameter change of both deep arteries after injection was Rt: 58.1 +/- 41.5%; left: 52.3 +/- 35.6%. The peak velocity of right cavernosal arterial flow after intracoporeal injection was 35.5 +/- 15.9 cm/sec; and that of the left side was 33.2 +/- 16.9 cm/sec. There was no correlation between the increment of peak velocity of the deep arterial flow and the erection grade. The same phenomenon was also found between the increased change in the diameter of the deep artery and the erection grade. 16 patients (34.1%) experienced tolerable pain during the procedure. Two patients (4.3%) experienced dizzines and discomfort due to venous leakage. No priapism was found. This study suggests PGE1 may be an excellent potential alternative to other vasoactive drug with less complication in the diagnosis and treatment of impotence. But the cost and stability were its shortcoming.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of hepatocellular carcinoma by transcatheter arterial chemoembolization and analysis of prognostic factors

A total of 100 patients with histologically proven hepatocellular carcinoma (HCC) underwent transcatheter arterial chemoembolization (TACE) and were followed for more than 1 year and 10 months. Portal vein branch thrombosis was diagnosed in 14 patients, and extrahepatic metastasis was noted in 11 subjects. The embolization material used was iodized oil (0.1-0.2 ml/cm tumor area at its maximal diameter), which was prepared by pumping with contrast agent and then mixed with anticancer drugs; Gelfoam particles measuring 1-2 mm in size were subsequently injected. The overall cumulative 0.5- 1-, 2-, and 3-year survival rates were 81%, 57%, 31%, and 21%, respectively. Patients with an intact capsule and those with solitary lesions, especially when the tumor diameter was < 5 cm, achieved a higher survival rate. In contrast, incomplete TACE, extrahepatic metastasis, and portal vein thrombosis were associated with the worst outcome. Patients with positive HBsAG and diffuse or multiple tumors also showed a poor outcome. Early diagnosis and early treatment of HCC are the keys for the achievement of better clinical results.

[An investigation of radiation exposure on pediatric patients and doctors during cardiac catheterization and cineangiography]

Cardiac catheterization and cineangiography are invasive diagnostic radiological examinations which exposure the patient to a relatively high radiation dose, the largest radiation dose of any diagnostic examination. Sixty-one infants and children, aged 28 days to 15 years, were randomly selected into this study to assess such questions regarding cardiac catheterization in children as; (1) How much the pediatric patient's and doctor's radiation exposure is during a routine cardiac catheterization and cineangiography? (2) What difference are there in exposure to various areas of the body? (3) How much radiation exposure is related to cineangiography compared with fluoroscopy? (4) How much radiation exposure may be reduced by lead apron worn by doctors? Thermoluminescent dosimeters containing 80 mg of CaSO4: Dy were applied to the body for the measurement of radiation exposure during cardiac catheterization. In hemodynamic assessment of catheterization (mean time 6 +/- 5 min), dosimeters were placed on various areas of the patient's skin and unexposed dosimeters were attached to mid sternum and right lateral chest during cineangiography (mean time 11 +/- 5 sec). Average skin doses over the patients' organs during catheterization and cineangiography were: eye 51 mu Gy, thyroid 746 mu Gy, sternum 5,102 mu Gy, right lateral chest 10,098 mu Gy, umbilicus 123 mu Gy and gonad 24 mu Gy. The radiation exposure during cineangiography at sternum and right lateral chest contributed to 61% and 70% of total exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Colour duplex sonography in the assessment of impotence

We present our experience with colour duplex sonography (Acuson 128) in the assessment of 83 impotent men. Cavernosal artery measurements were taken before and after the intracorporeal injection of papaverine. The peak velocities following papaverine injection correlated well with the degree of clinical response. Percentage diameter change corresponded with some groups of clinical erection grade, although it was not as good a discriminator as peak velocity. Twelve patients with 24 cavernosal arteries were also examined using pharmacological selective arteriography. Correlation between duplex sonography and arteriography showed an accuracy of 87.5%, specificity of 100.0% and sensitivity of 82.4%. All patients with a clinically good response following papaverine injection had peak bilateral cavernosal artery velocities greater than or equal to 25 cm/s. Amongst the remaining suboptimal responders, 18 also had this finding. Fifteen of these underwent pharmacological cavernosography and 14 exhibited venous leakage. Duplex sonography is a valuable and non-invasive tool in the assessment of impotence and can provide valuable information in deciding the course of further evaluation and treatment. The procedure was always completed more quickly with the guidance of colour Doppler.

Radiation exposure of pediatric patients and physicians during cardiac catheterization and balloon pulmonary valvuloplasty

Thermoluminescent dosimeters were applied to various areas of 61 pediatric patients and physicians to measure radiation doses during routine cardiac catheterization and during 4 cases of balloon pulmonary valvuloplasty. Radiation doses were measured during chest roentgenography, fluoroscopy and cineangiography. Average skin dose to the chest was 121 microGy during chest x-ray, 5,182 microGy during catheterization and 641 mGy during valvuloplasty. For the eyes, thyroid and gonads of the patients, the exposure during routine catheterization was equal to 0.4, 6 and 0.2 chest x-rays, respectively. Radiation dose of the operator was 3 microGy for the eyes and 6 miCroGy in the thyroid. About 56% of the operator's dose could be reduced by thyroid shields, and 80% by lead aprons. The assistant received only 1 microGy outside the thyroid shield. Therefore, we have concluded that the patients' dose during routine catheterization is largely based on our experimental results, but the dose is acceptable based on the risk factor analysis. The skin dose to the right lateral chest of the patient during valvuloplasty is extremely high, perhaps as high as the equivalent of 1,000 chest x-rays. Besides the clinical benefits of valvuloplasty, the long-term radiation-related hazards to the patient should be carefully monitored.

[Penile revascularization: report of 4 cases]

From February to June in 1989, 4 patients consulted our ward with the complaint of impotence. After each patient's history and physical examination were taken, a series of tests were administered which included hepatic and renal function, blood sugar, cholesterol, triglyceride, testosterone, prolactin level, nocturnal penile tumescence (NPT), duplex sonography, cavernosography, and internal pudendal arteriography. The results of these tests suggested vasculogenic impotence and penile revascularization was attempted. In 2 patients the Michal-II method was used. The second patient was treated with the Virag-V method. In the fourth patient, the Michal-II method was combined with the administration of the Virag-V method. After 6 months of follow-up, objective tests such as NPT and a Duplex scanning examination showed moderate improvement in the patients who received the Virag-V method, alone or in combination with the Michal-II method. Subjectively, all the patients except the one who received just the Virag-V method, felt improvement in erection angle, penetration, and satisfaction. We conclude that penile revascularization may be a more noninvasive, physiological alternative to penile prosthesis for some cases of vasculogenic impotence.

[Evaluation of impotence: intracorporeal injection of papaverine by color duplex sonography]

From February 1989 to June 1989, 49 patients consulted our OPD for the complaint of impotence. The average age was 46.9 +/- 11.2 y/0. We applied intracorporeal injection of papaverine (60 mg) by color duplex sonography (Acuson 128) for evaluation. The results of the papaverine test were: good response in 6 (12%), imperfect response in 21 (43%) and impaired response in 22 (45%). So the total positive response rate was 55%; and the total negative response rate was 45%; two patients (4%) experienced priapism. Spontaneous detumescence occurred after aspiration of the corpus cavernosum and no complications ensued. We utilized duplex sonography for evaluating penile blood flow before and after papaverine injection. Diameters of the deep artery was: right artery increased from 0.42 +/- 0.13 mm to 0.76 +/- 0.26 mm, while the left artery increased from 0.43 +/- 0.19 mm to 0.64 +/- 0.31 mm. Following injection, the peak velocity and the increased change of peak velocity were higher in patients in the positive response group than in the negative response group. There was no correlation for the percent of increase in diameter of the deep arteries. This technique provides a safe method with few complications for the objective assessment of response to intracorporeal papaverine injection and the anatomic structure of the penis. Use of this technique can also avoid unnecessary examinations and influence the strategy of treatment. After normal values and parameters are established, this method should be a useful diagnostic tool.

Regulation of neuroblast proliferation by hormones and growth factors in chemically defined medium

Pure neuronal cultures prepared from 6-day-old embryonic chick brains incorporated [3H]-thymidine in serum-free medium up to the 4th day in culture. The addition of insulin any time within this culture period caused an increase in thymidine incorporation. This increase in [3H]-thymidine was correlated with an increase in cell number and percentage of labeling index. Triiodothyronine and endothelial cell growth factor were also active in stimulating [3H]-thymidine incorporation into chick neuroblasts. The effect of these trophic agents is unique since a variety of known mitogens tested were negative.

Induction of glutamine synthetase in rat astrocytes by co-cultivation with embryonic chick neurons

Co-cultivation of confluent rat astrocyte cultures with embryonic chick neurons resulted in induction of glutamine synthetase activity in the astrocytes. This induction of glutamine synthetase in astrocytes by neurons was independent of induction by hydrocortisone and forskolin, but was dependent on the length of co-cultivation and the number of neurons present in the co-culture. Cycloheximide and actinomycin D inhibited the induction of glutamine synthetase in astrocytes by neurons, whereas cytosine arabinoside had no apparent effect. Results suggest that this induction of glutamine synthetase in astrocytes is mediated by cell contact with neurons and may represent a specific neuronal and glial interaction.

The expression of the intermediate filament-associated protein (NAPA-73) is associated with the stage of terminal differentiation of chick brain neurons

The monoclonal antibody E/C8 was originally generated against chicken dorsal root ganglia. The antigen detected by E/C8, NAPA-73, is an intermediate filament-associated protein. NAPA-73 was shown to be one of the earliest neuronal markers to appear during development since it appears in some neuronal precursor cells of the peripheral nervous system during development. Using [3H]thymidine pulse-chase experiments combined with immunocytochemistry, it is shown that the dividing neuroblasts from 6-day-old embryonic chick brains do not express NAPA-73. Only neurons that have undergone their terminal cell division either in the embryo or in cell culture express the E/C8 immunoreactivity. We conclude that E/C8 is a marker for postmitotic neurons in chick brain. The contrast between our findings and previous reports identifying NAPA-73 as one of the earliest neuronal markers may reflect a difference between the central and peripheral nervous systems.

Modulation of beta-adrenergic response in rat brain astrocytes by serum and hormones

Purified astrocyte cultures from neonatal rat cerebrum respond to isoproterenol, a beta-adrenergic agonist, with a transient rise in cAMP production. This astroglial property was regulated by serum, a chemically defined medium (serum-free medium plus hydrocortisone, putrescine, prostaglandin F2 alpha, insulin, and fibroblast growth factor) and epidermal growth factor. Compared to astrocytes grown in serum-supplemented medium, astrocytes grown in the chemically defined medium were nonresponsive to isoproterenol stimulation, and this difference did not appear to be due to selection of a subpopulation of cells by either medium. The data suggest that a decreased beta-adrenergic receptor number and an increased degradation of cAMP may account for the reduced response to beta-adrenergic stimulation. The nonresponsive state of astrocytes in the defined medium was reversible when the medium was replaced with serum-supplemented medium. An active substance(s) in serum was responsible for restoring the responsiveness of astrocytes. Each of the five components of the defined medium had little effect by itself; however, together they acted synergistically to desensitize astrocytes to beta-adrenergic stimulation. On the other hand, epidermal growth factor, a potent mitogen for astrocytes, was very competent by itself in reducing the cAMP response of astrocytes to beta-adrenergic stimulation. Thus purified astrocytes grown in the chemically defined medium appear to be a good model for the study of hormonal interactions and of serum factors which may modulate the beta-adrenergic response.

A high sensitivity LiF thermoluminescent dosimeter--LiF(Mg, Cu, P)

This paper describes the dosimetric properties of a new, high-sensitivity thermoluminescence dosimeter material prepared in our laboratory. The sensitivity of the LiF(Mg, Cu, P) phosphor is about 23 times higher than that of LiF (TLD-100). Its TL response is linear from 0.3 mR to 1000 R. Its energy dependence is similar to that of LiF (TLD-100). It is stable and reusable without significant loss of sensitivity. Its application to environmental radiation monitoring is described.

Neuroblastoma membranes inhibit isoproterenol-stimulated rise of cAMP in glioma cells

C6 glioma cells respond to beta-adrenergic agonists (isoproterenol) with a transient rise in intracellular cyclic adenosine monophosphate level. This beta-responsiveness of C6 cells is inhibited by the presence of a plasma membrane fraction, which has a five- to six-fold purification of membrane markers, showed a greater inhibition of beta-responsiveness in C6 cells than any other subcellular fractions of B104 cells. The inhibitory effector(s) is apparently associated with integral membrane structure(s) since ionic extraction and treatment with chelating agents did not remove the effect from the particulate membrane fraction. The effector is probably proteinaceous in nature as judged by its susceptibility to inactivation by heat and protease treatment. The data indicate that neither adenylate cyclase nor phosphodiesterase enzyme is likely to be directly involved in mediating the beta-nonresponsiveness of C6 cells.