Risk factors for portal vein system thrombosis after partial splenic embolisation in cirrhotic patients with hypersplenism.

AIM: To determine risk factors for portal venous system thrombosis (PVST) after partial splenic artery embolisation (PSAE) in cirrhotic patients with hypersplenism. MATERIALS AND METHODS: Between March 2014 and February 2022, 428 cirrhotic patients with hypersplenism underwent partial splenic artery embolisation and from these patients 208 were enrolled and 220 were excluded. Medical records of enrolled patients were collected. Computed tomography (CT) images were reviewed by two blinded, independent radiologists. Statistical analyses were performed by using SPSS. RESULTS: Progressive PVST was observed in 18.75% (39/208) of cirrhotic patients after PSAE. No significant differences in peripheral blood counts, liver function biomarkers, and renal function were observed between the patients with progressive PVST and the patients without progressive PVST. The imaging data showed significant differences in PVST, the diameters of the portal, splenic, and superior mesenteric veins between the progressive PVST group and non-progressive PVST group. Univariate and multivariate analysis demonstrated portal vein thrombosis, spleen infarction percentage, and the diameter of the splenic vein were independent risk factors for progressive PVST. Seventeen of 173 (9.83%) patients showed new PVST; the growth of PVST was observed in 62.86% (22/35) of the patients with pre-existing PVST. Spleen infarction percentage and the diameter of the splenic vein were independent risk factors for new PVST after PSAE. CONCLUSION: The present study demonstrated portal vein thrombosis, spleen infarction percentage, and the diameter of the splenic vein were independent risk factors for PVST after PSAE in cirrhotic patients with hypersplenism.

[Outcome of surgical repair for aortic coarctation with coexisting descending aortic aneurysm in adult patients].

Objective: To evaluate the efficacy of surgical treatment of aortic coarctation combined with descending aortic aneurysm in adult patients. Methods: This is a retrospective cohort study. Adult patients with aortic coarctation who were hospitalized in Beijing Anzhen Hospital from January 2015 to April 2019 were enrolled. The aortic coarctation was diagnosed by aortic CT angiography, and the included patients were divided into the combined descending aortic aneurysm group and the uncomplicated descending aortic aneurysm group based on descending aortic diameter. General clinical data and surgery-related data were collected from the included patients, and death and complications were recorded at 30 days after surgery, and upper limb systolic blood pressure was measured in all patients at discharge. Patients were followed up after discharge by outpatient visit or telephone call for their survival and the occurrence of repeat interventions and adverse events, which included death, cerebrovascular events, transient ischemic attack, myocardial infarction, hypertension, postoperative restenosis, and other cardiovascular-related interventions. Results: A total of 107 patients with aortic coarctation aged (34.1±15.2) years were included, and 68 (63.6%) were males. There were 16 cases in the combined descending aortic aneurysm group and 91 cases in the uncomplicated descending aortic aneurysm group. In the combined descending aortic aneurysm group, 6 cases (6/16) underwent artificial vessel bypass, 4 cases (4/16) underwent thoracic aortic artificial vessel replacement, 4 cases (4/16) underwent aortic arch replacement+elephant trunk procedure, and 2 cases (2/16) underwent thoracic endovascular aneurysm repair. There was no statistically significant difference between the two groups in the choice of surgical approach (all P>0.05). In the combined descending aortic aneurysm group at 30 days after surgery, one case underwent re-thoracotomy surgery, one case developed incomplete paraplegia of the lower extremity, and one case died; and the differences in the incidence of endpoint events at 30 days after surgery were similar between the two groups (P>0.05). Systolic blood pressure in the upper extremity at discharge was significantly lower in both groups compared with the preoperative period (in the combined descending aortic aneurysm group: (127.3±16.3) mmHg vs. (140.9±16.3) mmHg, P=0.030, 1 mmHg=0.133 kPa; in the uncomplicated descending aortic aneurysm group: (120.7±13.2) mmHg vs. (151.8±26.3) mmHg, P=0.001). The follow-up time was 3.5 (3.1, 4.4) years. There were no new deaths in the combined descending aortic aneurysm group, no transient ischemic attack, myocardial infarction or re-thoracotomy surgery, and one patient (1/15) suffered cerebral infarction and 10 patients (10/15) were diagnosed with hypertension. The differences in the occurrence of endpoint events during postoperative follow-up were similar between the two groups (P>0.05). Conclusion: In experienced centers, long-term prognosis of patients with aortic coarctation combined with descending aortic aneurysm is satisfactory post surgical intervention.

[Analysis of clinical features of 380 cases of special portal hypertension-Abernethy malformation].

Objective: To summarize the clinical features of special portal hypertension-Abernethy malformation reported at home and abroad. Methods: The relevant literature on Abernethy malformation published at home and abroad from January 1989 to August 2021 was collected. Patients'clinical features, imaging and laboratory test results, diagnosis, treatment, and prognosis were analyzed. Results: A total of 380 cases were included from 60 and 202 domestic and foreign literatures. Among them, there were 200 cases of type I, with 86 males and 114 females, and the average age was (17.08±19.42) years, while there were 180 cases of type II, with 106 males and 74 females, and the average was (14.85±19.60) years. The most common reason for the first visit of an Abernethy malformation patient's was gastrointestinal system symptoms such as hematemesis and hematochezia caused by portal hypertension (70.56%). Multiple malformations were present in 45.00% of type Ⅰ and 37.80% of type Ⅱ patients. The most prevalent condition was congenital heart disease (62.22%, and 73.53%). Complications related to Abernethy malformation was occurred in 127 and 105 cases with type I and type II, respectively, with liver lesions in 74.02% (94/127) and 39.05% (42/105) and hepatopulmonary syndrome of 33.07% (42/127) and 39.05% (41/105), respectively. The imaging diagnosis of type I and type II Abernethy malformations were mainly based on abdominal computed tomography (59.00%, and 76.11%). Liver pathology was performed in 27.10% of patients. Blood ammonia increased by 89.06% and 87.50%, and AFP increased by 29.63% and 40.00% in laboratory findings. 9.76% (8/82) and 6.92% (9/130) died, while 84.15% (61/82) and 88.46% (115/130) had improved conditions after medical conservative, or surgical treatment. Conclusion: Abernethy malformation is a rare disease in which congenital portal vein development abnormalities lead to significant portal hypertension and portasystemtic shunt. Patients often seek medical treatment for gastrointestinal bleeding and abdominal pain. Type Ⅰ is more common in women, often associated with multiple malformations, and prone to secondary intrahepatic tumors. Liver transplantation is the main treatment method. Type Ⅱ is more prevalent in males, and shunt vessel occlusion is the first treatment choice. Overall, type Ⅱ has a better therapeutic impact than type Ⅰ.

[Resting-state functional magnetic resonance imaging analysis of modified electroconvulsive therapy in the treatment of major depressive disorder].

Objective: To explore the effect of modified electroconvulsive therapy (MECT) on resting-state functional connectivity (RSFC) in patients with major depressive disorder (MDD). Methods: Patients with MDD from Anhui Mental Health Center from October 2017 to May 2019 were included. Using bilateral nucleus accumbens (NAcc) as seed points, changes of RSFC were investigated before and after MECT through resting-state functional magnetic imaging (fMRI). Antidepressant effects were measured by 17 items of Hamilton Depressive Rating Scale (HDRS-17). Correlation analysis was performed between changed HRSD-17 scores and changes of functional connectivity. Results: A total of 40 MDD patients (10 males and 30 females), aged (38±11) years, who received MECT were included in the study. After MECT, patients showed increased RSFC in the right NAcc (rNAcc) and superior frontal gyrus (P<0.001), right supramarginal gyrus (P<0.001), right angular gyrus (rAG) (P= 0.017), right inferior parietal lobule (P= 0.017), left superior frontal gyrus (LSFG) (P<0.001), left middle temporal gyrus (P=0.017) and left angular gyrus (LAG) (P=0.012), respectively. The RSFC changes of rNAcc-LSFG (r=-0.454, P = 0.003), rNAcc-rAG (r=-0.437, P=0.005) and rNAcc-lAG (r=-0.383, P=0.015) were negatively correlated with the changes of HRSD-17 scores. Conclusions: MECT may alleviate major depression by regulating the functional connectivity between the rNAcc and bilateral angular gyrus and left superior frontal gyrus.

Systematic review of the effects of environmental factors on virus inactivation: implications for coronavirus disease 2019.

Environmental factors such as temperature and relative humidity can affect the inactivation and transmission of coronaviruses. By reviewing medical experiments on virus survival and virus transmission between infected and susceptible species in different temperature and humidity conditions, this study explores the influence of temperature and relative humidity on the survival and transmission of viruses, and provides suggestions, with experimental evidence, for the environmental control measures of Coronavirus Disease 2019. The results indicated that (1) virus viability and infectivity is increased at a low temperature of 5 â„ƒ and reduced at higher temperatures. (2) Virus survival and transmission is highly efficient in a dry environment with low relative humidity, and also in a wet environment with high relative humidity, and it is minimal at intermediate relative humidity. Therefore, in indoor environments, the lack of heating in winter or overventilation, leading to low indoor temperature, can help virus survival and help susceptible people being infected. On the contrary, modulating the indoor relative humidity at an intermediate level is conducive to curb epidemic outbreaks.

Better view by detachable string magnetically controlled capsule endoscopy for esophageal observation: a retrospective comparative study.

Magnetically controlled capsule endoscopy (MCE) system has been used to screen gastric lesions. However, the visualization performance of MCE in the esophagus has not been investigated systematically. String method improved the ability of capsule endoscopy (CE) for esophageal observing; however, the string attachment is complicated and cannot be detached with the CE inside the esophagus. We used a modified string, called detachable string attached to MCE. The aim of the study was to compare the observation performance of MCE with and without the detachable string. A total of 238 participants with upper gastrointestinal symptoms and a healthy check who refused esophagogastroduodenoscopy examination were retrospectively divided into the detachable string MCE group and the MCE alone group from June 2016 to May 2018. A suction cap with a thin, hollow string was attached to the MCE system in the detachable string group. Circumferential visualization of the esophagus including the upper, middle, and lower esophagus and Z-line, and esophageal focal lesion, as well as the recording time, safety and tolerability of the procedure, were assessed. The circumferential visualization of the upper, middle, and lower esophagus and Z-line was more efficient in the detachable string MCE group than in the MCE alone group (P < 0.001). In all, 31 esophageal lesions were detected in the detachable string MCE group, which was more than that in the MCE alone group (10, P < 0.001). The mean recording time was 305 seconds in the string MCE group, which was longer than that in the MCE alone group (48.5 seconds, P < 0.001). In seven participants (6.1%) in the detachable string MCE group, the capsule could not be separated from the string. Detachable string MCE showed better performance in terms of observation of the esophagus. Detachable string MCE can be used to screen for esophageal diseases as an alternative method in the future.

Association between rs12252 and influenza susceptibility and severity: an updated meta-analysis.

In several lately published studies, the association between single-nucleotide polymorphism (SNP, rs12252) of IFITM3 and the risk of influenza is inconsistent. To further understand the association between the SNP of IFITM3 and the risk of influenza, we searched related studies in five databases including PubMed published earlier than 9 November 2017. Ten sets of data from nine studies were included and data were analysed by Revman 5.0 and Stata 12.0 in our updated meta-analysis, which represented 1365 patients and 5425 no-influenza controls from four different ethnicities. Here strong association between rs12252 and influenza was found in all four genetic models. The significant differences in the allelic model (C vs. T: odds ratio (OR) = 1.35, 95% confidence interval (CI) (1.03-1.79), P = 0.03) and homozygote model (CC vs. TT: OR = 10.63, 95% CI (3.39-33.33), P < 0.00001) in the Caucasian subgroup were discovered, which is very novel and striking. Also novel discoveries were found in the allelic model (C vs. T: OR = 1.37, 95% CI (1.08-1.73), P = 0.009), dominant model (CC + CT vs. TT: OR = 1.48, 95% CI (1.08-2.02), P = 0.01) and homozygote model (CC vs. TT: OR = 2.84, 95% CI (1.36-5.92), P = 0.005) when we compared patients with mild influenza with healthy individuals. Our meta-analysis suggests that single-nucleotide T to C polymorphism of IFITM3 associated with increasingly risk of severe and mild influenza in both Asian and Caucasian populations.

[Reoperation for residual aneurysm of coronary anastomosis after Bentall procedure].

Objective: To introduce a new operative method for residual aneurysm of coronary anastomosis after Bentall procedure. Methods: Between March 2011 and December 2012, six patients in Beijing Anzhen Hospital with residual aneurysm of coronary anastomosis (CT showed goldfish eye sign at the openings of coronary) after Bentall procedure underwent the operation of concentric circular patch procedure under cardiopulmonary bypass. Femoral artery, right atrium and upper right pulmonary artery cannulation were used for cardiopulmonary bypass, and the artificial vessel was transected after cardiac arrest. A concentric circular patch was pruned, whose outside diameter was slightly larger than the aneurysm and the inside diameter was equal to the openings of coronary. The outer edge of the patch was anastomosed to the outer edge of the aneurysm (opening of artificial vessel in primary surgery) with 4-0 prolene. The inner edge of the patch was anastomosed to the openings of coronary with 5-0 prolene. Results: All patients had clinical recovery. Postoperative CT demonstrated the disappearance of residual aneurysm during follow-up (the goldfish eye sign disappeared). Conclusion: The concentric circular patch procedure is a feasible treatment for residual aneurysm of coronary anastomosis.

[Surgical treatment of aortic dissection with lower extremity ischemia].

Objective: To explore the clinical outcome of the surgical treatment for aortic dissection with lower extremity ischemia. Methods: Between March 2009 and April 2013, 14 patients with type A aortic dissection and lower extremity ischemia underwent Sun's procedure in Beijing Anzhen Hospital. Ascending aorta-iliac artery bypass, ascending aorta-femoral artery bypass, femoral-femoral artery bypass and axillary -femoral artery bypass were performed on some severe patients at the same time. Results: Two death occurred, and the others were improved or recovered from symptoms. Follow-up was complete with an average time of 24 months and no aortic relevant complications occurred. Conclusion: As for patients with type A aortic dissection and lower extremity ischemia, simultaneous radical femoral artery bypass procedure is effective in improving their survival rate and quality of life.

[Atypical polypoid adenomyoma of the uterus: a clinicopathological review of 27 cases].

Objective: To investigate the clinical and pathological characteristics of atypical polypoid adenomyoma (APA) for improvement of the diagnosis, different diagnosis and treatment of the disease. Methods: The clinical data, pathological characteristics, and the follow-up information were retrospectively analyzed in 27 cases of APA admitted in Peking Univeristy People's Hospital from 2007 to 2016. Results: The median age was 42.6 years old (range 25-60 years old). Fifteen patients were nullipara, 2 patients were postmenopausal. The most common presenting symptom was abnormal uterine bleeding (81%, 22/27) . Leisions were obtained by using hysteroscopy in 23 cases, hysterectomy 3 cases and dilatation and curettage 1 case. Fertility preserving treatments were performed in 10 patients who had strong desire for fertility, among which 1 case progressed into endometrial carcinoma. Among 15 patients underwent hysterectomy and (or) bilateral salpingo-oophorectomy, 9 cases of them had endometrial atypical hyperplasia. Endometrial carcinoma along with APA were found in three patients, 2 cases of them underwent hysterectomy and bilateral salpingo-oophorectomy and pelvic lymphadenectomy, the other one received medication for fertility preservation. Follow up information were available in 24 cases (89%, 24/27) with a median follow up of 46 months (range 4-108 months), 1 case recurred and 1 case progressed into endometrial carcinoma. One case died of other malignancy, while the other patients were alive. Conclusions: APA is a rare uterine neoplasm mixed with epithelial and mesenchymal component. It occurs mostly in childbearing-age women and its diagnosis is dependent on pathology. Although it's clinical course is benign, there is risk of co-existance of endometrial carcinoma and endometrial atypical hyperplasia. For those who has desire of fertility, the treatment strategy is completely removed the lesion and closely followed up. For those who do not desire to preserve fertility, hysterectomy may be an option.

Genetic analysis of BMP4 gene in Chinese Han female population with premature ovarian insufficiency.

The bone morphogenetic protein 4 (BMP4) gene is related to development of female reproductive organs in animal models. However, to date, there has been no consensus on the relationship between mutations in BMP4 and premature ovarian insufficiency (POI) in human beings. To analyze variations in BMP4 in Chinese women with POI, we sequenced two coding regions of BMP4 in 99 Han Chinese women with POI after DNA extraction and amplification by polymerase chain reaction (PCR). We found no any mutation in the BMP4 coding regions. Only one SNP rs17563 was detected among women with POI. However, the allele frequency of rs17563 presented no significant differences between POI patients and the international HapMap Project data for CHB and CHD. Our findings suggest that the BMP4 gene may not represent a risk factor in the development of POI among Chinese Han women.

[Biomechanical analysis of miniplate fixation systems in restorative laminoplasty for spinal canal reconstruction].

OBJECTIVE: To investigate the biomechanical properties of H-shaped and L-shaped miniplate fixation systems (H-MFS and L-MFS, respectively) in restorative laminoplasty for spinal canal reconstruction (RL-SCR). METHODS: Laminectomy was performed in a 3D printed L4 vertebral model followed by RL-SCR using H-MFS or L-MFS, and the biomechanical properties of the reconstructed models were evaluated using static and dynamic compression tests. Biomechanical analyses of RL-SCR were also conducted in finite element models of the L3-L5 vertebrae with normal assignment (NA), laminectomy, or fixation with H-MFS or L-MFS, and the range of motion (ROM) of L3-L4 and L4-L5 was evaluated. RESULTS: In static compression test, the sustained yield load, compression stiffness, yield displacement and axial displacement- axial load were all significantly greater in H-MFS group (P < 0.05). Door closing, lamina collapse and plate breakage occurred in all the models in L-MFS group, and only some models in H-MFS group showed plate cracks and screw loosening. In dynamic compression tests, the peak load in H-MFS group reached 873 N (which was 95% of the average yield load in static compression), significantly greater than that in L-MFS group (P < 0.05). The ultimate load in L-MFS group was only 46.59% of that in H-MFS group (P>0.05). In finite element analysis, the ROM of the L3-L4 and L4- L5 segments were significantly smaller in NA, H-MFS and L-MFS groups than in laminectomy group. Compared with NA group, H-MFS group showed a greater ROM during extension, and L-MFS group showed greater ROM in flexion, extension, bending, and rotation; The overall ROM of the vertebral segments decreased in the order of laminectomy group, L-MFS group, H-MFS group, and NA group. CONCLUSION: Laminectomy causes structural destruction of the posterior column of the spine to affect its biomechanical stability. RL-SCR can effectively maintain the biomechanical stability of the spine, and H-MFS is superior to L-MFS in maintaining the integrity and biomechanical properties of the reconstructed spinal canal.

RapidArc combined with the active breathing coordinator provides an effective and accurate approach for the radiotherapy of hepatocellular carcinoma.

PURPOSE: The goal of this research was to investigate the feasibility of volumetric modulated arc therapy, RapidArc (RA), in association with the active breathing coordinator (ABC) for the treatment of hepatocellular carcinoma (HCC) with radiotherapy. PATIENTS AND MATERIALS: A total of 12 patients with HCC, after receiving transcatheter arterial chemoembolization (TACE) treatment, underwent three-dimensional computer tomography (3D-CT) scanning associated with ABC using end inspiration hold (EIH), end expiration hold (EEH), and free breathing (FB) techniques. The three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and RA plans (three 135° arcs) were designed on different CT images, respectively. The liver volume, gross tumor volume (GTV), and planning target volume (PTV) of the three breath status and the dosimetric differences of the different plans were compared. RESULTS: There were no significant differences in the volumes of live and GTV between the three breathing techniques (p > 0.05); the PTV in FB was greater than in the EEH and EIH (p < 0.05). The overall conformality index (CI) and homogeneity index (HI) for RA (CI 0.92, HI 0.90) were better than IMRT (CI 0.90, HI 0.89) and 3D-CRT (CI 0.70, HI 0.84) for the three breathing techniques (p< 0.05). The RA and IMRT significantly reduced the mean dose, V(20), V(30), and V(40) of normal liver compared to 3D-CRT, while the V(5) and V(10) in RA were higher than in IMRT. The mean values in mean dose, V(10), V(20), V(30), and V(40) of the normal liver were reduced from 13.12 Gy, 46%, 24%, 13%, and 8% in RA(FB) to 10.23 Gy, 35%, 16%, 8%, and 5% in RA(EEH) and 9.23 Gy, 32%, 16%, 8%, and 5% in RA(EIH ), respectively. In addition, the treatment time of RA was equal to 3D-CRT, which was significantly shorter than IMRT. CONCLUSION: RA in conjunction with ABC for the treatment of HCC with radiotherapy can achieve better dose delivery and ensure the accuracy of the target volume, which spares more organs at risk, uses fewer monitor units, and shortens treatment time.

Microwave-assisted one-step patterning of aqueous colloidal silver.

A new approach of utilizing microwave to pattern gradient concentric silver nanoparticle ring structures has been presented. The width and height of a single ring and the space between adjacent rings can be adjusted by changing the silver colloidal concentration and the microwave output power. By simply enhancing the ambient vapour pressure to the saturated value during microwave-assisted evaporation, sub-100 nm rings can be deposited in between adjacent micro-rings over a distance of millimetres. Combined with microwave sintering, this approach can also create conductive silver tracks in a single step, showing huge potential in fabricating micro- and nano-electronic devices in an ultra-fast and cost-effective fashion.

Trends in seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus among patients seeking care in China.

We determined seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus in outpatients in China from December 2009 to March 2010. Serum antibody titers were determined by a hemagglutination-inhibition (HI) assay using the seroprevalence data for 2006-2008 (1.2%) as baseline. The overall seroprevalence was 7.6%, 18.6%, 20.5%, and 20.0% in December 2009, January 2010, February 2010, and March 2010, respectively. In comparison of monthly data, the seroprevalence values for the first three months exhibited statistically significant differences. As for the age-specific seroprevalence, the individuals aged demic virus.

Specific downregulation of death-associated protein kinase enhances Fas-mediated apoptosis in the human differentiated endometrial adenocarcinoma cell line, HHUA.

PURPOSE OF INVESTIGATION: Death-associated protein kinase (DAPK) is a serine/threonine kinase that is well-known as a positive mediator of Fas-mediated apoptosis. Previous reports have shown that DAPK and Fas are expressed in human endometrial adenocarcinoma cells. In this study, we examined the effects of specific downregulation of DAPK expression on Fas-mediated apoptosis in the human endometrial adenocarcinoma cell line, HHUA. METHODS AND RESULTS: Transfection of DAPK small-interfering RNAs (siRNAs) into the HHUA cells reduced DAPK protein expression, and enhanced Fas-mediated apoptosis, in a dose-dependent manner. CONCLUSIONS: These results indicate that, in contrast to cases with other malignant tumor cells, DAPK negatively regulates Fas-mediated apoptosis in these human differentiated endometrial adenocarcinoma cells.

Explanation for fracture spacing in layered materials

The spacing of opening-mode fractures in layered materials--such as certain sedimentary rocks and laminated engineering materials--is often proportional to the thickness of the fractured layer. Experimental studies of this phenomenon show that the spacing initially decreases as extensional strain increases in the direction perpendicular to the fractures. But at a certain ratio of spacing to layer thickness, no new fractures form and the additional strain is accommodated by further opening of existing fractures: the spacing then simply scales with layer thickness, which is called fracture saturation. This is in marked contrast to existing theories of fracture, such as the stress-transfer theory, which predict that spacing should decrease with increasing strain ad infinitum. Recently, two of us (T.B. and D.D.P.) have used a combination of numerical simulations and laboratory experiments to show that, with increasing applied stress, the normal stress acting between such fractures undergoes a transition from tensile to compressive, suggesting a cause for fracture saturation. Here we investigate the full stress distribution between such fractures, from which we derive an intuitive physical model of the process of fracture saturation. Such a model should find wide applicability, from geosciences to engineering.

Airway smooth muscle thickness in asthma is related to severity but not duration of asthma.

Asthma is characterised by an increased airway smooth muscle (ASM) area (ASM(area)) within the airway wall. The present study examined the relationship of factors including severity and duration of asthma to ASM(area). The perimeter of the basement membrane (PBM) and ASM(area) were measured on transverse sections of large and small airways from post mortem cases of fatal (n = 107) and nonfatal asthma (n = 37) and from control subjects (n = 69). The thickness of ASM (ASM(area)/PBM) was compared between asthma groups using multivariate linear regression. When all airways were considered together, ASM(area)/PBM (in millimetres) was increased in nonfatal (median 0.04; interquartile range 0.013-0.051; p = 0.034) and fatal cases of asthma (0.048; 0.025-0.078; p<0.001) compared with controls (0.036; 0.024-0.042). Compared with cases of nonfatal asthma, ASM(area)/PBM was greater in cases of fatal asthma in large (p<0.001) and medium (p<0.001), but not small, airways. ASM(area)/PBM was not related to duration of asthma, age of onset of asthma, sex or smoking. No effect due to study centre, other than that due to sampling strategy, was found. The thickness of the ASM layer is increased in asthma and is related to the severity of asthma but not its duration.