[Efficacy and safety of modified Hartel approach in the treatment of primary trigeminal neuralgia with radiofrequency thermocoagulation]

Objective: To assess the efficacy and safety of modified Hartel approach in the treatment of primary trigeminal neuralgia with radiofrequency thermocoagulation. Methods: A total of 89 patients with primary trigeminal neuralgia in Nanjing Drum Tower Clinical College of Xuzhou Medical University from July 2021 to July 2022 were prospectively included, and were divided into experimental group (n=45, modified Hartel approach: selecting 2.0 cm lateral to and 1.0 cm below angulus oris as insertion point) and control group (n=44, traditional Hartel approach: selecting 2.5 cm lateral to the angulus oris as insertion point) according to the random number table method. There were 19 males and 26 females in the experimental group, and aged (67.6±8.8) years. Meanwhile, there were 19 males and 25 females in the control group, and aged (64.8±11.7) years. All the patients were treated by CT-guided radiofrequency thermocoagulation. The success rate of one-time puncture, number of punctures, the time of puncture, operation time, numerical rating scale (NRS) scores and complications were recorded and compared between the two groups. Results: The success rate of one-time puncture in experimental group was 64.4% (29/45), which was higher than that in control group 31.8% (14/44) (P<0.05). The number of punctures [M (Q₁, Q₃)], the time of puncture [M (Q₁, Q₃)] and operation time in the experimental group were 1 (1, 2), 218 (206, 378) s, (19.9±2.7) min, which were less than those of control group [2 (1, 3), 390 (231, 598) s, (27.0±3.9) min] (all P<0.05). The NRS scores [M (Q₁, Q₃)] of 1 day, 1 month and 3 months after surgery in the experimental group were 1 (1, 2), 1 (0, 2) and 1(0, 1), respectively, which were lower than the baseline level [6 (6, 7)] (all P<0.05). The NRS scores [M (Q₁, Q₃)] of 1 day, 1 month and 3 months after surgery in the control group were 1 (1, 2), 1 (0, 2) and 1 (0, 2), respectively, which were lower than the baseline level [6 (6, 7)] (all P<0.05). There was no statistically significant difference in the incidence of nausea and vomiting, facial numbness, and decreased masticatory muscle strength between the two groups (all P>0.05) In the experimental group, two patients had puncture needles into the oral cavity, with timely detection and replacement of puncture needles, and no infection occurred. There was no cerebrospinal fluid leakage and decreased corneal reflex in both groups. Conclusion: The modified Hartel approach can significantly improve the success rate of one-time puncture via foramen ovale, reduce the operation time and the incidence of postoperative facial swelling, which is a safe and effective puncture method.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

[Application of 3D-printed navigation plate in pulsed radiofrequency therapy of dorsal root ganglion in thoracic postherpetic neuralgia]

Objective: To evaluate the accuracy, efficacy and safety of 3D-printed personalized navigation template in the treatment of thoracic postherpetic neuralgia (PHN) with dorsal root ganglion pulsed radiofrequency (DRG-PRF). Methods: A total of 63 patients with thoracic PHN from March 2019 to December 2020 in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School were enrolled and randomly divided into study group (n=31) and control group (n=32) by random number table method. The study group received DRG-PRF treatment assisted by 3D-printed navigation template, while the control group received DRG-PRF treatment guided by conventional CT. The one-time success rate of puncture, the incidence of puncture times ≥3, the number of punctures, puncture time, visual analogue scale (VAS) score and surgical complications between the two groups were compared. Results: The one-time success rate of puncture in study group was 84.9% (79/93), which was higher than that of control group [30.2% (29/96)] (P<0.001). The incidence of puncture times ≥3, the number of punctures, puncture time in study group were 4.3% (4/93), 1 (1, 1) and 2.9 (2.8, 3.0) min, respectively, which were lower than that of the control group [21.9% (21/96), 2(1, 3), 9.0 (4.5, 12.9) min, respectively] (all P<0.01). No difference was found in VAS score at each time point before and after surgery between the two groups (all P>0.05). There was one case of pleura puncture in the control group, but no other complications such as straying into vertebral canal, hematoma, spinal cord injury, limb movement disorder, infection were found in the two groups. Conclusions: 3D-printed personalized navigation template is an effective method to guide DRG-PRF for the treatment of thoracic postherpetic neuralgia. It can significantly improve the surgical efficiency of DRG-PRF, but has no significant effect on the surgical efficacy.

[Clinical characteristics and treatment of myoepithelial carcinoma of head and neck]

Objective:To investigate the clinical features, diagnosis, treatment and prognosis of myoepithelial carcinoma of the head and neck. Method:The clinical data of 59 patients with head and neck myoepithelial carcinoma admitted from January 2012 to October 2018 were analyzed retrospectively. The data was analyzed with SPSS 21.0 statistical software. Result:The follow-up period was 6 to 131 months. The mean follow-up time was 36 months. One patient（1.7%） was lost to follow-up, 17 patients（28.8%） had postoperative local recurrence, 8 patients（13.6%） had distant metastasis, and 5 patients（8.5%） had cervical lymph node metastasis; 14 patients（23.7%） died. The 1-, 3-, and 5-year cumulative survival rates were 92%, 73%, and 62%, respectively. Survival rate curves of different treatment methods were significantly different by Gehan method（P<0.05）. Compared between the two groups, there was significant difference between surgery alone and surgery plus radiotherapy than radiotherapy alone and chemotherapy alone（P<0.05）. There was no significant difference between the other two treatment methods. Multivariate logistic regression analysis showed that tumor location, clinical stage and survival status and local recurrence rate were significantly correlated（P<0.05）, but gender, age and survival status and local recurrence rate were not significantly correlated（P>0.05）. Conclusion:The incidence of myoepithelial carcinoma is low, and the clinical manifestations and imaging studies lack specificity. The tumor is prone to local recurrence, invasive, and has a high incidence of distant metastasis. It is a highly malignant tumor. Surgical treatment is preferred and the requirements for first surgery are high, and major salivary glands and advanced tumors（stage Ⅲ-Ⅳ） are risk factors for survival and local recurrence. Early diagnosis and early treatment can significantly improve the survival rate of patients, reduce the local recurrence rate of tumors, and improve the prognosis of patients.

[Status of non-steroidal anti-inflammatory drugs use in areas with a high incidence of upper gastrointestinal cancer in China: a multi-center cross-sectional survey]

Objective: To describe the status of non-steroidal anti-inflammatory drugs (NSAIDs) use in areas with a high incidence of upper gastrointestinal cancer in China. Methods: This study was based on the National Key Research and Development Program of "National Precision Medicine Cohort of Esophageal Cancer" and "Study on Identification and Prevention of High-risk Populations of Gastrointestinal Malignancies (Esophageal cancer, Gastric cancer and Colorectal cancer)" . From January 2017 to August 2018, 212 villages or communities with a high incidence of esophageal cancer or gastric cancer were selected from 12 regions in 6 provinces. A total of 35 910 residents aged between 40 and 69 years old who met the inclusion criteria and signed the informed consent were investigated and enrolled in this study. The use of NSAIDs, demographic characteristics, health-related habits, height, weight, and blood pressure were collected by the questionnaire and physical examination. The status of main NSAIDs (aspirin, acetaminophen and ibuprofen) use with the difference varying in genders, age groups and regions were analyzed by using χ(2) test and Cochran-Armitage trend analysis method. Results: Of 35 910 subjects, the mean age was (54.6±7.1) years old and males accounted for 43.42% (15 591). The overall prevalence of NSAIDs intake was 4.56% (1 638), but it significantly varied in different provinces (P<0.001). The overall prevalence of NSAIDs intake was 4.87% (1 750) in females, which was significantly higher than that in males 4.24% (1 524) (P<0.001). The prevalence of NSAIDs intake increased with age (P for trend <0.001). As the frequency of NSAIDs intake increased, the incidence of gastrointestinal symptoms, gastrointestinal ulcers and black stools increased (P for trend <0.05 for all). Conclusion: The use of NSAIDs is prevalent in some areas with a high incidence of upper gastrointestinal cancer in China. The increased use of NSAIDs may lead to more adverse effects related to the gastrointestinal tract.

[Analysis of incidence and mortality for upper digestive tract cancers and results of early detection and treatment program in Feicheng, Shandong Province]

Objective: To investigate the trend of esophageal and stomach cancer incidence and mortality in Feicheng during 2000 to 2013, and to evaluate the effects of the national project of screening for upper digestive tract cancers from 2006 to 2015 in Feicheng. Methods: We collected 26 569 cases, which were coded of C15 and C16 in the 10th edition of international classification of diseases (ICD) during the period of 2000-2013. The data came from cancer registration system of Feicheng, Shandong Province, China. These cases already covered 21 679 882 person-year. The annual percent change (APC) of incidence and mortalit were analyzed. The risk factors of upper gastrointestinal cancer were investigated and evaluated for people aging 40-69 in three street offices and eleven townships of Feicheng, and endoscopic screening was conducted among people who was in high risk. The corresponding data were used to analyze the early detection project of upper gastrointestinal cancer screening and early diagnosis, with the index of detection rate, early diagnosis rate, early treatment rate and other indicators. Result: There were 26 569 new cases of esophageal cancer and gastric cancer occurred in Feicheng from 2000 to 2013. The incidence of esophageal cancer gradually increased since 2000 with 76.06 per 100 000 people (575/756 005) and reached the peak in 2010 with incidence rate of 118.76 per 100 000 people (852/717 429), with the annual percent change at about 4.3% (95%CI: 2.7%-5.9%) and showed a downward trend after then but has no significance, with APC about-7.1% (95%CI:-15.8%-2.5%). The incidence of gastric cancer was increased from 2000 with an incidence rate of 37.70 per 100 000 people (285/756 005) to 2013 with an incidence rate of 54.59 per 100 000 (538/985 512), with an annual percent change of about 3.3% (95%CI: 2.1%-4.5%). Esophageal cancer and gastric cancer mortality showed a relatively stable trend during 2000 to 2013, esophageal cancer with APC about 0.1% (95%CI: -1.3%-1.5%) and stomach cancer with APC about 0.8% (95%CI: -0.5%-2.0%). From 2006 to 2015, 58 579 residents aged 40-69 years old participated cancer screening project covered 206 105 populations in Feicheng. There were 1 124 invasive cancers and in situ cases from upper digestive tract were detected, with the detective rate at 1.92%. Among those cases, 941 cases were in early stage with the early diagnosis rate of 83.72%, and about 88.97% of detected patients received appropriate treatment after diagnosis. Conclusion: The incidence of esophageal cancer and gastric cancer with a very high level of incidence and mortality, this made the prevention and control situation was still very serious. The project of cancer screening, early diagnosis and treatment on upper digestive tract cancers in Feicheng plays a positive role on cancer control.

miR-106a* inhibits the proliferation of esophageal carcinoma cells by targeting CDK2-associated Cullin 1 (CACUL1)

Previous studies suggest that aberrant microRNA expression is common in plenty of cancers. The expression of miR-106a* was decreased in follicular lymphoma, but the expression and functions of miR-106a* in esophageal carcinoma (EC) remain unclear. In this study, we explored the expression and anti-oncogenic roles of miR-106a* in human EC. The expression of miR-106a* is significantly decreased in EC tissues and EC cell lines. Overexpression of miR-106a* suppressed EC cell proliferation, clonogenicity, G1/S transition, and induced apoptosis in vitro, but inhibition of miR-106a* facilitated cell proliferation, clonogenicity, G1/S transition. Luciferase reporter assay results showed that CDK2-associated Cullin 1 (CACUL1) was a direct target of miR-106a* in EC cells. Moreover, silencing CACUL1 resulted in the same biologic effects of miR-106a* overexpression in EC cells, which included suppressed EC cell proliferation, clonogenicity, and blocked G1/S transition through CDK2 pathway by inhibiting cell cycle regulators (Cyclin A, Cyclin E). Our data indicate that miR-106a* might play an anti-oncogenic role in EC by regulating CACUL1 expression, which suggest miR-106a* as a new potential diagnostic and therapeutic target for EC.

An expression of squamous cell carcinoma antigen 2 in peripheral blood within the different stages of esophageal carcinogenesis

The malignant transformation of esophageal mucosa is a progressive process, which includes basal cell hyperplasia, dysplasia, carcinoma in situ, and invasive esophageal squamous cell carcinoma (ESCC). The objectives of this study were to prove the relationship of squamous cell carcinoma antigen 2 (SCCA2) mRNA expression in peripheral blood with non-malignant lesion, premalignant lesion, and carcinoma of the esophagus at the same assay, as well as to evaluate whether or not SCCA2 mRNA expression in peripheral blood may be a biomarker for monitoring the premalignant lesion of the disease. The subjects consisted of 50 patients with basal cell hyperplasia, 50 patients with dysplasia, 50 patients with ESCC (12 carcinoma in situ, 38 carcinoma in invasive stage), and 50 controls who were pathologically diagnosed to be normal and whose esophageal mucosa were stained brown by iodine. All the subjects are residents of Feicheng, China, which is considered an area with a high incidence of esophageal cancer. All subjects were diagnosed by two separate histopathologists, and the expression of SCCA2 mRNA in peripheral blood was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, SCCA2 concentration in the serum was measured using an enzyme-linked immunosorbent assay (ELISA). In the cancer group, SCCA2 mRNA expression was also detected in 20 tissues of esophageal cancer. By using the band intensity ratios of SCCA2 to beta-actin, with a positive cut-off value of > or = 0.4, the positive rates of the SCCA2 mRNA expression in peripheral blood were found to be 82% (41/50), 60% (30/50), 48% (24/50), and 36% (18/50) in the cancer, dysplasia, basal cell hyperplasia, and control groups, respectively. The positive rate of the cancer group was significantly different from the three other groups (P < 0.05), and there was also a significant difference in the SCCA2 mRNA expression between the dysplasia group and the control group (chi(2)=5.769, P= 0.016). In the multinomial logistic regression analysis, the odds ratios (ORs) were 1.71 [95% confidence interval (95% CI), 0.73-3.99] in the basal cell hyperplasia group, 2.77 (95% CI, 1.14-6.71) in the dysplasia group, and 7.87 (95% CI, 2.88-21.55) in the cancer group after being adjusted for age, gender, smoking index, drinking index, and family history of esophageal cancer. The SCCA2 mRNA expression in peripheral blood was then divided into different grades according to the band intensity ratios of SCCA2 to beta-actin. By using a positive cut-off value of > or = 0.4, the testing sensitivities in the basal cell hyperplasia, dysplasia, and cancer groups were found to be 48%, 60%, and 82%, respectively, with the same testing specificity at 64%. On the other hand, SCCA2 mRNA expression in peripheral blood had a 97.5% agreement with that in tissue, and there was a significant correlation between the ELISA SCCA2 levels in the serum and the SCCA2 mRNA expression levels in the peripheral blood (r= 0.80, P= 0.01). The results indicate that SCCA2 mRNA expression in peripheral blood is linked with the different stages of esophageal pathological changes, despite the fact that SCCA2 mRNA was not a biomarker for screening early esophageal cancer. This knowledge may be useful in monitoring the processes of change that occur in esophageal premalignant lesions among subjects who live in a high-incidence area.

Regulation of Vibrio alginolyticus virulence by the LuxS quorum-sensing system

Quorum sensing (QS) is a bacterial intercommunication system that controls the expression of multiple genes in response to population density. The LuxS QS system regulates the expression of several virulence factors in a wide variety of pathogenic bacteria. LuxS has been characterized to be responsible for producing a type of autoinducer, AI-2, which stimulates the expression of the luciferase operon in Vibrio harveyi. Vibrio alginolyticus is established as an opportunistic pathogen of several marine animals, and its LuxS QS system remains undefined. To investigate the pathogenic role of luxS in V. alginolyticus, the luxS mutants of both the standard strain ATCC 33787 and a fish-clinical isolate MVP01, named MYJS and MYJM, respectively, were constructed. The mutation resulted in reduced lethality to Pagrus major. Intraperitoneal LD(50) of MYJS and MYJM increased by 15- and 93-fold, respectively. The two luxS mutants exhibited a lower growth rate and defective flagellar biosynthesis. They also showed a significant decrease in protease production and an increase in both extracellular polysaccharide production and biofilm development. The results suggest that the LuxS QS system plays an important role in regulating the expression of virulence factors in V. alginolyticus.

How to map ses, a mutant of Arabidopsis thaliana affecting pollen development

In Arabidopsis, map-based cloning has been developed to an effective method in mutant genetic analysis because high-density markers are available, candidate genes or genomic sequences can be amplified by PCR and transgenic techniques are simplified. Mutant ses named from shortened early-stage siliques was used as an example to show how to map a mutant in this day. By the process of bulked segregants analysis, linkage testing, large-scale and fine scale mapping, mutant ses was narrowed into a 67 kb interval from CER448792 (2000541 bp) to CER464544 (2067844 bp) crossing over the right of BAC F12K11 to the left of the BAC F4H5 including at most 22 putative genes on the top of chromosome l. In sequence-based map of Arabidopsis genes with Mutant phenotype (SMAGMP) mutant ses was between ATlg06150 (EMB1444) and ATlg08060 (MOM). The SES mapping also showed that developed markers on polymorphism site of CAPC not only were simplified and but worked well. 24 markers from CAPC used in the mapping maybe help Arabidopsis researches with others and the methods related to SES mapping also gave an example of positional cloning.

Surgical treatment of nonunited fractures of the odontoid process, with special reference to occipitocervical fusion for unreducible atlantoaxial subluxation or instability

Fifty-seven consecutive patients treated surgically for nonunited fractures of the odontoid process were reviewed. All patients presented late, exhibiting neurological deficits subsequent to nonunion. Delay in presentation was between 6 and 120 months (mean 32 months) after the original injury, due to missed diagnosis or inappropriate management. Seven patients who were reduced in traction underwent a Gallie atlantoaxial fusion. In the remaining 50 patients who were unreducible, an occipitocervical arthrodesis was performed. They were followed up for a minimum of 2 years, except one who died from postoperative respiratory failure. All patients obtained a solid bony union, including two in whom nonunion occurred following atlantoaxial fusion, and occipitocervical fusion was added as a rescue. Thirty-eight patients achieved excellent neurological recovery, nine still had some disability, five retained their neurological deficits and two reported a deterioration. In two patients, a recurrence in a traumatic episode was experienced long after a resolution. Our findings demonstrate that occipitocervical arthrodesis is preferable for unreducible subluxation or instability of atlantoaxial articulation in nonunion of odontoid fractures.

Transgenic plants expressing autoantigens fed to mice to induce oral immune tolerance

Oral administration of protein can induce antigen-specific immune hyporesponsiveness. However, the utility of oral tolerance to autoantigens in the treatment of autoimmune diseases may be limited when candidate autoantigens cannot be produced by conventional systems in quantities sufficient for clinical studies. Plants may be ideally suited for this purpose, as they can synthesize, glycosylate and assemble mammalian proteins to provide huge quantities of relatively low cost soluble proteins. Furthermore, edible transgenic plants could provide a simple and direct method of autoantigen delivery for oral tolerance. Therefore, the aim of this study was to determine whether a transgenic plant expression system was capable of synthesizing the diabetes-associated autoantigen, glutamic acid decarboxylase (GAD) in an immunogenic form and whether the oral administration of an autoantigen expressed by a plant could directly induce protective immune responses in a mouse model of diabetes. We show that a GAD-expressing transgenic plant, given as a dietary supplement, inhibits the development of diabetes in the non-obese diabetic (NOD) mouse.

[The design of a model of the experimental cervical spondylosis]

A model of the cervical spondylosis in the rabbits was established with press-injection of saline into the space between C5 and C6. The formation of the osteophytes at the posterior corner of the vertebra and the slight compression of the spinal cord were found in 4 months after the injection. The swelling, degeneration and rupture of the annulus fibrosus, the regeneration of fibrocartilage cells and the deposition of calcium extending to the posterior part of the vertebral body were observed under light microscope. The pathological changes were similar to those of the cervical spondylosis in the human being.

Bile salt-induced increases in duodenal brush-border membrane proton permeability, fluidity, and fragility

Rabbit duodenal brush-border membrane vesicles were treated in vitro with deoxycholate, glycodeoxycholate, or taurodeoxycholate. Intravesicular [14C]glucose space at equilibrium, 0.54 microliters/mg protein, was reduced by exposure to the three bile salts in a concentration (0.1-5.0 mM)-dependent manner, equatable with increased membrane fragility. Net proton permeability (Pnet), determined by acridine orange fluorescence quenching, was increased from 6.3 x 10(-4) cm/sec in untreated vesicles, by approximately 120, 150, and 170%, by treatment with bile salts at 0.1, 0.5 and 1.0 mM, respectively. The three bile salts were equipotent. The increases in membrane fragility and Pnet were not accompanied by significant increases in membrane fluidity, as assessed from steady-state and time-resolved diphenylhexatriene fluorescence anisotropy. The data demonstrate direct effects of bile salts on duodenal apical membrane fragility and proton permeability that are likely to be early events in bile salt-induced mucosal damage.

The effects of a new cholinolytic--8018--and its optical isomers on the central muscarinic and nicotinic receptors

3-(2'-phenyl-2'-cyclopentyl-2'-hydroxyl-ethoxy)quinuclidine (8018), a new cholinolytic, is a racemic tertiary amine with two chiral carbonic atoms. It has 4 optical isomers whose absolute configurations are RR', SR', RS' and SS'. These compounds showed potent pharmacological activity, blocking both central muscarinic and nicotinic receptors. Central muscarinic receptors, rather than nicotinic receptors, have a stereoselective specificity to these compounds. The R configuration of both substituted alkoxyl and alkalinic alcohol parts is more suitable to the stereostructure of the binding site of muscarinic receptors than the S configuration. These compounds can prevent soman-induced electroencephalographic seizures in rats by both their central M- and N-cholinolytic actions.

[Experimental study of degenerative arthritis of the patello-femoral joint]

In order to investigate the pathological changes and stages of development of degenerative arthritis, a model of degenerative arthritis of patello-femoral joint was established in 30 rabbits by shortening the patellar tendon by 4 mm. The animals were killed 1,2,4,6,8,12 weeks after operation, and the results showed that the compression force between patella and femoral condyle increased 1/4 and a typical change of degenerative arthritis was a observed grossly and histologically and ultrastructurally. The authors consider that this kind of model may be used for further study of prevention and treatment of degenerative arthritis.

Comparison of bile salt perturbation of duodenal and jejunal isolated brush-border membranes

Rabbit duodenal and jejunal brush-border membrane vesicle integrity, fluidity and passive proton permeability were studied after in vitro exposure to deoxycholate, glycodeoxycholate or taurodeoxycholate. Duodenal and jejunal membrane mean vesicle volume [0.54 (0.05) and 0.54 (0.03) microliters/mg, mean values with SE in parentheses], and proton permeability [6.30 (0.02) x 10(-4) and 5.59 (0.17) x 10(-4) cm.S-1] were similar, while membrane fluidity was slightly, but significantly, greater in jejunal membranes [diphenylhexatriene fluorescence anisotropy, (r0/r)-1 = 0.499 (0.013) and 0.572 (0.012)]. The three bile salts (0.1-5.0 mM) caused concentration-related decreases in vesicle integrity as assessed by [14C]glucose retention at equilibrium. Jejunal membranes were more sensitive at low bile salt concentrations, 0.1 and 0.5 mM. With high concentrations of bile salts, 5 mM, above their critical micelle concentrations, less than 10% of jejunal or duodenal vesicles remained. The bile salts caused concentration-related increases in jejunal membrane fluidity over the range 0.1-1.0 mM bile salt, but duodenal membrane fluidity was only increased at the highest concentration of bile salt. Proton permeability (Pnet) of the membranes was increased by the bile salts (0.1-1.0 mM), and again the jejunal membranes were more sensitive; Pnet increased by approximately 120, 150 and 170 in duodenal, and 150, 220 and 380% in jejunal membranes, with deoxycholate at 0.1, 0.5 and 1.0 mM, respectively. There were no consistent differences in the potency of the unconjugated and conjugated bile salts. The three variables were only significantly correlated for duodenal membranes.(ABSTRACT TRUNCATED AT 250 WORDS)