[Silent pulmonary shadows]

An elderly woman with a 1-year history of pulmonary shadows was admitted because of intermittent cough and sputum production for 2 months. Chest computed tomography (CT) scans showed bilateral consolidations and ground-glass opacities, with areas of low attenuation inside consolidative opacities on the mediastinal window. Previous history of radiotherapy for nasopharyngeal carcinoma and long-term use of a compound menthol nasal drops provided were important clues to the diagnosis. CT scan-guided needle lung biopsy and bronchoalveolar lavage were performed, and lipid-laden macrophages were confirmed in both bronchoalveolar lavage and lung tissue. Final diagnosis of exogenous lipoid pneumonia was made on the basis of her risk factors for aspiration, history of oil exposure, and classic radiological and histopathological features. Symptoms improved after discontinuation of causative exposure. It is important for clinicians to raise awareness of exogenous lipoid pneumonia and other aspiration lung diseases.

[Comparative study of decompression of unilateral biportal endoscopic compared to laminectomy with fusion and internal fixation in the treatment of severe lumbar spinal stenosis]

Objective: To compare the clinical efficacy of unilateral biportal endoscopy unilateral laminotomy for bilateral decompression (UBE-ULBD) to posterior lumbar interbody fusion (PLIF) in the treatment of severe lumbar spinal stenosis (SLSS). Methods: The clinical data of 64 patients with SLSS treated with PLIF and UBE-ULBD in Dalian Central Hospital Affiliated to Dalian Medical University from April 2018 to April 2021 were collected and divided into UBE group and PLIF group according to the different surgical procedures. There were 30 cases in the UBE group, including 12 males and 18 females, aged (69.8±6.8) years. There were 34 patients in the PLIF group, including 15 males and 19 females, aged (69.3±6.3) years. The operation time, intraoperative blood loss, surgical complications, the volume of drainage, transfusion, post-operative bed rest time, postoperative hospital stay, surgical costs of both groups were recorded and analyzed. The visual analogue scales (VAS) of back/leg pain (pre-operation and 1 d, 1 month, 6 month, 12 month post-operation) and Oswestry disability index (ODI) (pre-operation and 1 month, 6 month, 12 month post-operation) were used to determine the outcome. And the dural sac cross-sectional area (DSCA) and Schizas grade of both groups preoperatively and 6 month postoperatively were recorded. Results: The operation time in the UBE group was (69.2±8.0) min, it was lower than that in the PLIF group (139.0±15.3) min (P<0.05). The intraoperative blood loss and drainage in the UBE group were (19.5±5.6) ml and (15.0±10.8) ml, which were both lower than those in the PILF group [(212.4±34.1) ml and (169.6±43.8) ml] (both P<0.05). The postoperative bed rest time and hospital stay in the UBE group were (1.8±0.7) days and (3.0±0.9) days, which were both shorter than those in the PLIF group [(4.5±1.4) days and (7.1±1.7) days] (both P<0.05). The surgical cost was also lower in the UBE group than that in the PLIF group [RMB,(18.4±1.0) thousands yuan vs (33.9±2.4) thousands yuan, P<0.05]. In addition, no patient received blood transfusion in the UBE group. Dural sac tear occurred in 2 cases in the UBE group and in 3 cases in PLIF group; nerve root injury and infection occurred in one case in the PLIF group, respectively. In the PLIF group, the VAS of back pain was not significantly improved 1 day after operation when compared with that before the operation, but it significantly improved 1 month, 6 months and 1 year after operation (all P<0.05). The VAS for back pain at 1 day after operation and ODI at 1 month after operation in the UBE group were significantly superior to those in the PLIF group (both P<0.05), while there was no significant difference between the two groups in the VAS for back pain at 1 month, 6 months and 1 year after operation and ODI at 6 months and 1 year after operation. Both groups got significant canal expansion after the surgery and the PLIF group showed larger canal expansion extent (all P<0.05). Both groups improved significantly after surgery in the Schizas grade, there were 25 cases in UBE group improved to grade A, 5 cases to grade B while 30 cases in PLIF group improved to grade A, 4 cases to grade B, but there was no significant difference between the two groups (P>0.05). Conclusion: ULBD-UBE could achieve full decompression of the whole spinal canal with limited structures damage in treating SLSS. Compared with PLIF, UBE-ULBD could get complete decompression as well as less iatrogenic damage, it may be an ideal alternative surgical technique for SLSS with less invasion.

[Waxing and waning pulmonary nodules and cavities]

We reported a case of vascular Ehlers-Danlos syndrome presenting with recurrent pulmonary hemorrhage. A 22-year-old man was admitted for intermittent hemoptysis and chest pain during the past 18 months. Computed tomography of chest showed bilateral nodules and cavities with halo sign. Inflammatory markers, including erythrocyte sedimentation rate, C reactive protein and interleukin 6, were within normal range. The microbiological and pathological examination of bronchoalveolar lavage fluid and CT-guided percutaneous lung biopsy failed to draw a diagnosis. The pulmonary lesions waxed and waned despite empirical antibacterial, antifungal, antimycobacterial, and anti-parasite treatment. Video-assisted thoracoscopic lung biopsy showed pulmonary hemorrhage, hematoma, ossification, and fibrous nodules, suggesting vascular Ehlers-Danlos syndrome. The molecular testing revealed a heterozygous missense variant in the COL3A1 gene which confirmed the diagnosis of vascular Ehlers-Danlos syndrome. The patient had no skin hyperextensibility or joint hypermobility. During 3-year follow-up, there were no evidence of other vascular or organ involvement except he had intermittent minor hemoptysis. Through this clinical pathological discussion, we aimed to remind pulmonologist to consider the possible diagnosis of vascular Ehlers-Danlos syndrome in young patients with recurrent hemoptysis and waxing and waning pulmonary nodules, cavities, or cysts on CT scan who has neither obvious systematic inflammation nor effective reaction on empirical antimicrobial therapy. Molecular testing should be carried out as soon as possible in a suspected patient to avoid unnecessary invasive examinations.

[Subcutaneous nodules, mediastinal and hilar lymphadenopathy]

A 52-year old man was admitted to our hospital because of dyspnea on exertion for 2 months and subcutaneous nodules for 1 month. Chest enhanced CT showed bilateral hilar and mediastinal lymphadenopathy. Bronchial alveolar lavage fluid revealed a CD₄⁺/CD₈⁺ T cell subsets ratio of 4.3 and culture for acid-fast bacillus (AFB) was negative. The pathology of skin nodules and transbronchial needle aspiration biopsy guided by endoscopic ultrasound (EBUS-TBNA) revealed non-caseating necrotizing epithelioid granulomas with negative acid-fast bacilli staining and periodic acid-Schiff staining, which was compatible with sarcoidosis. The patient was diagnosed as sarcoidosis and glucocorticoid was administrated. The subcutaneous nodules were improved. However, the lymph nodes were enlarged instead of shrinking after 6-month therapy. The failure to respond to glucocorticoids raised the possibility of sarcoidosis complicated with tuberculosis infection. The patient received anti-tuberculosis therapy. Lymphadenopathy responded within 4 months, and there was complete regression after 18-month treatment. The patient was followed up for 5 years and repeated chest CT scan showed that the sizes of bilateral hilar and mediastinal lymph nodes were normal.

[Diagnostic value of surgical lung biopsies for diffuse parenchymal lung disease: the change of disease spectrum in the past 28 years in a single institution in China]

Objective: To investigate the changes of disease spectrum in diffuse parenchymal lung disease (DPLD) diagnosed by surgical lung biopsy, and to explore the diagnostic value of surgical lung biopsy in DPLD. Methods: Four hundred and fifty-five consecutive DPLD patients, who underwent surgical lung biopsy in Peking Union Medical College Hospital during the past 28 years, were analyzed retrospectively. Results: There were 211 males and 244 females. The average age at biopsy was (45±14) years. Four hundred and eleven cases (90.3%) were diagnosed by pathologic findings. Four hundred and forty-one cases (96.9%) were diagnosed by clinical-radiologic-pathologic multidisciplinary discussion. The 30-day mortality and 90-day mortality were 2.4% and 3.3% respectively. The disease spectrum included interstitial pneumonia in 209 cases (45.9%) (nonspecific interstitial pneumonia in 105 cases, usual interstitial pneumonia in 33 cases), other miscellaneous DPLD in 166 cases (36.5%) (including hypersensitivity pneumonitis in 49 cases), tumor in 39 cases (8.6%), and infectious diseases in 27 cases (5.9%). In the three consecutive periods (1993-2002, 2003-2012 and 2013-2020), the number of biopsies was 76 (16.7%), 297 (65.3%) and 82 (18%) respectively. The disease spectrum changes over time: in the above three periods, the percentage of interstitial pneumonia in DPLD was 68.4%, 45.1% and 28%, other miscellaneous DPLDs were 22.4%, 39.4% and 39.0%, the tumors were 2.6%, 7.4% and 18.3%, the infectious diseases were 5.3%, 5.1% and 9.8%. Conclusions: This study presented the changes of disease spectrum in DPLD diagnosed by surgical lung biopsy through single center real-world data, reflecting the progress of clinicians' understanding of DPLD and interstitial pneumonia. Surgical lung biopsy is still valuable for some difficult and complicated DPLD cases.

Partial thyroxine-binding globulin deficiency in a family with coding region mutations in the TBG gene

PURPOSE

T4-binding globulin (TBG) is the main thyroid hormone (TH) transporter present in human serum. Inherited thyroxine-binding globulin (TBG) deficiency is caused by mutations in the TBG (SERPINA7) gene, which is located on the X chromosome. This study was performed to report and evaluate coding region mutations in TBG gene for partial thyroxine-binding globulin deficiency.

METHODS

A pedigree spanning four generations is described in this study. The proband is a female with partial TBG deficiency. All members of this pedigree underwent thyroid function tests, while Sanger sequencing was used to identify the TBG gene mutations. Bioinformatics databases were used to evaluate the deleterious effects of the mutation(s). Two hundred and seven unrelated individuals were used to evaluate the thyroid function of individuals with different TBG mutations. A one-way ANOVA was used to analyze the impact of the TBG mutations on thyroid function.

RESULTS

TBG gene sequencing results revealed that the proband had a novel mutation in codon 27 leading to alanine to valine substitution (p.A27V). This mutation was associated with lower serum T4 levels (p < 0.0001) when compared to the groups that did not carry the mutation. The previously reported p.L283F mutation was also found in the proband. The hemizygous p.L283F individuals presenting with lower T4 serum and TBG levels (p < 0.001) when compared to wildtype males and females. Both mutations were deleterious upon SIFT and PolyPhen-2 evaluation.

CONCLUSION

Associated with partial thyroxine-binding globulin deficiency, this study reports a novel p.A27V mutation in the TBG gene.

Characterization of emerging predominant HFMD pathogen, coxsackievirus A6 in mainland China

Hand, foot, and mouth disease (HFMD) had the highest yearly incidence, with over 10 million cases of HFMD annually reported in China. Enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) have been regarded as the leading pathogens of HFMD outbreaks worldwide and in China; however, in recent years, the leading pathogens have been changing, as large outbreaks of CV-A6-associated HFMD have been reported worldwide. Since 2013, repeated large-scale HFMD outbreaks caused by CV-A6 happened in mainland China, where, as a result, CV-A6 has surpassed EV-A71 and CV-A16 as the leading HFMD pathogen in most Chinese provinces.

We sequenced the whole genomes of 158 CV-A6 clinical samples that were isolated between 2010 and 2018 from the HFMD Surveillance Network established in our laboratory. Our results showed that: seven recombination forms (RFs) of Chinese CV-A6 were detected; different CV-A6 RFs showed distinct virulence and transmissibility; VP1283T may play an important role in the virulence of Chinese CV-A6.

HFMD epidemics in China have become a serious public health problem over the past decade. In this research, we have attempted to explore the causes of the high transmissibility of the emerging CV-A6 in mainland China on the basis of CV-A6 evolution based on 336 whole-genome sequences, and we have yielded some fruitful results for the future research and surveillance of HFMD in China.

Key messages

HFMD epidemics in China have become a serious public health problem over the past decade. CV-A6 has surpassed EV-A71 and CV-A16 as the leading HFMD pathogen in most Chinese provinces.

[The differential diagnosis for novel coronavirus pneumonia and similar lung diseases in general hospitals]

Novel coronavirus pneumonia was a novel coronavirus infection that has dominated pulmonary infection since December 2019. The main manifestations were fever, dry cough, shortness of breath, normal or leukopenia in peripheral blood and changes in chest CT and in severe cases, multiple organ failure might occur. The National Health Commission, PRC has revised the consensus on diagnosis and treatment seven times in a short period of time, indicating the growing understanding of the disease. Patients with novel coronavirus pneumonia usually had history of travelling or living in the epidemic area including Wuhan within 14 days before onset, or have been exposed to patients who had fever or respiratory symptoms from the epidemic area, or had clustering diseases. However, novel coronavirus pneumonia was becoming more and more blurred after vanishing epidemic. The diagnosis and differential diagnosis of novel coronavirus pneumonia were challenges not only because of large number of tourists increasing dramatically after the relieving of epidemic, but also patients with other diseases from different areas to search for medical care. In this article, the clinical and chest imaging features of the novel coronavirus pneumonia were reviewed and compared with other infections and non-infectious diffuse pulmonary diseases. We try to find the similarities and differences among them, and to identify clues to the diagnosis of novel coronavirus pneumonia, so as to ensure accurate diagnosis and treatment.

[The mechanism of HOTAIR regulating the proliferation and apoptosis of prostate cancer cells by targeting down-regulation of miR-152 to improve the expression of FOXR2]

Objective: To clarify the effect of FOXR2 on the proliferation and apoptosis of prostate cancer cells and to reveal the mechanism. Methods: The expression of FOXR2 in clinical samples of prostate cancer were detected by Quantitative Real-time PCR (qRT-PCR) and Western blotting. The CCK8 proliferation kit and the Annexin V-FITC apoptosis kit, flow cytometry were used to detect the proliferation and apoptosis of prostate cancer cells with or without the FOXR2 knockdown. Combined with the results of microRNA chip, we predicted the related miR-152 and detected the relationship between miR-152 and FOXR2 by luciferase reporter gene assay. The correlation between HOTAIR and miR-152 is clearly defined by software prediction and qRT-PCR. Results: FOXR2 had a relatively high expression in the prostate cancer tissue.The mRNA expression of FOXR2 is 4.9 times that of adjacent tissues, and the protein level was also significantly up-regulated. In the PC3 cell line, the specific knock-down of FOXR2 inhibits the proliferation of cells and promotes cell apoptosis. According to the microRNA chip results and luciferase reporter gene assay, we found miR-152 could regulate the expression of FOXR2; and FOXR2 3 'UTR had two miR-152 binding sites, all of which could control the expression of FOXR2. The results of LNCediting and qRT-PCR suggest that HOTAIR is negatively correlated with the expression of miR-152, and is involved in the regulation of miR-152 expression in prostate cancer. Conclusion: FOXR2 up-regulation can promote the proliferation and inhibit the apoptosis of prostate cancer cells because that HOTAIR restrains the expression of miR-152.

[CT study on the development of facial nerve canal in children]

Objective: To assess the characteristics of facial nerve canal between normal anatomy and dysplasia of children in different ages. Methods: A total of 492 health ears were divided into six groups, neonatal group (<1 m , n=42), infancy group(1 m-1 y, n=106), toddler group(1-3 y, n=102), preschool group (3-6 y, n=100), school group(6-10 y, n=60)and adolescent group (10-14 y, n=82). The length and diameter of facial nerve canal and that angles of first and second genu were measured with CT in each group. Results: ①The lengths of facial nerve canal in neonatal and infancy group were shorter than other four groups, especially in the mastoid segments of facial nerve canal. The lengths of mastoid segments in neonatal, infancy, toddler, preschool, school and adolescent groups were 5.03±0.84, 6.25±1.40, 8.34±1.38, 9.70±1.34, 10.84±1.41 and 12.17±1.83 mm, with P<0.05, respectively. After school age, the lengths of labyrinthine and tympanic segment grew slowly or developed completely (P>0.05). ② The diameter of labyrinth and tympanic segment in neonatal group were narrower than other five groups (P<0.05), but no significant difference among them in other groups (P>0.05). ③The dysplasia of facial nerve canal were occurred on 978 locations. Among them, the percentage of dehiscence, aberrance, partially expanding and bifurcation were 72.9%(713/978), 5.1%(50/978), 18.9%(185/978) and 3.1%(30/978) respectively. The percentage of dehiscence in geniculate fossa segment was decreased significantly with age (neonatal group 85.7%(36/42), infancy group 59.4%(63/106), toddler group 39.2%(40/102), preschool group 33%(33/100), school group 30%(18/60)and adolescent group 26.8%(22/82), with P<0.05). Except the dehiscence of geniculate fossa and mastoid segment, there was no significant difference in the occurrence rate of the other variants (P>O.05). Conclusions: The growth of length and dehiscence in labyrinth segment of facial nerve canal are significant in difference ages. The changes of diameter and angles of first and second genu in facial nerve canal, and the rate of other dysplasia are individual.

Facet orientation and tropism: Associations with asymmetric lumbar paraspinal and psoas muscle parameters in patients with chronic low back pain

BACKGROUND

Many studies have explored the relationship between facet tropism and facet joint osteoarthritis, disc degeneration and degenerative spondylolisthesis. However, the associations between facet orientation and tropism, and paraspinal muscles have not been studied.

OBJECTIVE

To analyze the associations between facet orientation and tropism, and parameters of paraspinal muscles in patients with chronic low back pain.

METHODS

Ninety-five patients with chronic low back pain were consecutively enrolled. Their facet joint angles were measured on computed tomography (CT) while gross cross-sectional area (GCSA), functional cross-sectional area (FCSA) and T2 signal intensity of lumbar paraspinal and psoas muscle were evaluated on magnetic resonance imaging (MRI).

RESULTS

The GCSA and FCSA were significantly smaller for multifidus muscle (P< 0.001), but significantly larger for erector spinae and psoas muscles (P< 0.001), in coronally-orientated group than those in sagittally-orientated group. The differences of bilateral GCSA and FCSA of multifidus muscle were significantly larger in facet tropism group than those in no facet tropism group (P= 0.009 and P= 0.019).

CONCLUSIONS

Muscular asymmetries may develop in the lumbar region of the spine, which are associated with facet asymmetry in patients with chronic low back pain. Longitudinal studies are needed to understand the causal relationship between facet orientation and tropism and muscular asymmetry in future.

Elevated plasma surfactant protein D (SP-D) levels and a direct correlation with anti-severe acute respiratory syndrome coronavirus-specific IgG antibody in SARS patients

Pulmonary SP‐D is a defence lectin promoting clearance of viral infections. SP‐D is recognized to bind the S protein of SARS‐CoV and enhance phagocytosis. Moreover, systemic SP‐D is widely used as a biomarker of alveolar integrity. We investigated the relation between plasma SP‐D, SARS‐type pneumonia and the SARS‐specific IgG response. Sixteen patients with SARS, 19 patients with community‐acquired pneumonia (CAP) (Streptococcus pneumonia) and 16 healthy control subjects were enrolled in the study. Plasma SP‐D and anti‐SARS‐CoV N protein IgG were measured using ELISA. SP‐D was significantly elevated in SARS‐type pneumonia [median (95% CI), 453 (379–963) ng/ml versus controls 218 (160–362) ng/ml, P < 0.05] like in patients with CAP. SP‐D significantly correlated with anti‐SARS‐CoV N protein IgG (r² = 0.5995, P = 0.02). The possible re‐emergence of SARS or SARS‐like infections suggests a need for minimal traumatic techniques for following the alveolar compartment, e.g. during testing of antivirals. We suggest that monitoring systemic SP‐D may be useful in monitoring the alveolar integrity in SARS‐type pneumonia. The significant correlation between plasma SP‐D and anti‐SARS‐CoV‐specific antibodies support the role for SP‐D in interlinking innate and adaptive immune pathways.

Structural and Functional Analysis of Giant Strong Component of Bacillus thuringiensis Metabolic Network

The purpose of this work was to study the giant strong component (GSC) of B. thuringiensis metabolic network by structural and functional analysis. Based on so-called “bow tie” structure, we extracted and studied GSC with its functional significance. Global structural properties such as degree distribution and average path length were computed and indicated that the GSC is also a small-world and scale-free network. Furthermore, the GSC was decomposed and functional significant for metabolism of these divisions were investigated by comparing to KEGG metabolic pathways.

Support vector machines for prediction of peptidyl prolyl cis/trans isomerization

A new method for peptidyl prolyl cis/trans isomerization prediction based on the theory of support vector machines (SVM) was introduced. The SVM represents a new approach to supervised pattern classification and has been successfully applied to a wide range of pattern recognition problems. In this study, six training datasets consisting of different length local sequence respectively were used. The polynomial kernel functions with different parameter d were chosen. The test for the independent testing dataset and the jackknife test were both carried out. When the local sequence length was 20-residue and the parameter d = 8, the SVM method archived the best performance with the correct rate for the cis and trans forms reaching 70.4 and 69.7% for the independent testing dataset, 76.7 and 76.6% for the jackknife test, respectively. Matthew's correlation coefficients for the jackknife test could reach about 0.5. The results obtained through this study indicated that the SVM method would become a powerful tool for predicting peptidyl prolyl cis/trans isomerization.

Identification, cloning, and expression of potential diagnostic markers for Q fever

The clinical diagnosis of Q fever is difficult. Whole cell antigens are currently used in several serological methods, but antigens are limited due to the hazardous nature of Coxiella burnetii cultivation. In this report, we described the method of detecting immunodominant antigens of C. burnetii by using proteomic techniques with patient sera, and cloning and expressing the selected antigens using a novel vector known for its ease of expression, purification, and downstream application.

[Studies on the pharmacokinetics and relative bioavailability of salbutamol aerosol in healthy volunteers]

AIM

To study the pharmacokinetics and relative bioavailability of salbutamol aerosol in healthy volunteers.

METHODS

An HPLC method for the determination of salbutamol in human plasma was improved. Ten healthy male subjects were enrolled. A randomized, two-way crossover, open design was adopted. After the subjects inhaled or orally administered salbutamol, fourteen blood samples were taken at predetermined time. The concentrations of salbutamol in plasma were determined by HPLC, and then assessed with PCNONLIN software to obtain the pharmacokinetic parameters and relative bioavailability of aerosol versus water solution.

RESULTS

The standard curve was linear over the range 0.2-20 ng.mL-1. The intra- and interassay RSDs were 7.01% and 2.10% at 0.4 ng.mL-1, 2.18% and 5.25% at 4.0 ng.mL-1 and 4.61% and 4.85% at 15.0 ng.mL-1. The recoveries were between 90% and 110%. The pharmacokinetics of salbutamol aersol was described well with a two-compartment model, and the parameters for salbutamol inhaled and orally administered were assessed as follows: Tmax were (0.22 +/- 0.07) h and (1.8 +/- 0.6) h, Cmax were (3.4 +/- 1.1) ng.mL-1 and (3.9 +/- 1.4) ng.mL-1, T1/2 beta were (4.5 +/- 1.5) h and (4.6 +/- 1.1) h, respectively. The AUC0-20 min (inhal) was 7.94 times as high as the AUC0-20 min (p.o.). There were significant differences between Tmax, AUC, K12, K21, alpha and T1/2 alpha (P < 0.05). The relative bioavailability of salbutamol aerosol was 57.23% compared with its oral solution.

CONCLUSION

The assay was sensitive, specific, accurate and precise. The absorption process of salbutamol aerosol in human was significantly different from that of the oral solution. It was demonstrated that AUC0-20 min reflected the lung availability of salbutamol inhaler.

Mechanisms of impaired beta-adrenoceptor-induced airway relaxation by interleukin-1beta in vivo in the rat

We studied the in vivo mechanism of beta-adrenergic receptor (beta-AR) hyporesponsiveness induced by intratracheal instillation of interleukin-1beta (IL-1beta, 500 U) in Brown-Norway rats. Tracheal and bronchial smooth muscle responses were measured under isometric conditions ex vivo. Contractile responses to electrical field stimulation and to carbachol were not altered, but maximal relaxation induced by isoproterenol (10(-6)-10(-5) M) was significantly reduced 24 h after IL-1beta treatment in tracheal tissues and to a lesser extent, in the main bronchi. Radioligand binding using [125I]iodocyanopindolol revealed a 32+/-7% reduction in beta-ARs in lung tissues from IL-1beta-treated rats, without any significant changes in beta2-AR mRNA level measured by Northern blot analysis. Autoradiographic studies also showed significant reduction in beta2-AR in the airways. Isoproterenol-stimulated cyclic AMP accumulation was reduced by IL-1beta at 24 h in trachea and lung tissues. Pertussis toxin reversed this hyporesponsiveness to isoproterenol but not to forskolin in lung tissues. Western blot analysis revealed an IL-1beta-induced increase in Gi(alpha) protein expression. Thus, IL-1beta induces an attenuation of beta-AR-induced airway relaxation through mechanisms involving a reduction in beta-ARs, an increase in Gi(alpha) subunit, and a defect in adenylyl cyclase activity.

The gene encoding human ribosomal protein S24 and tissue-specific expression of differentially spliced mRNAs

Starting with a cloned cDNA encoding human ribosomal protein S24 [Brown et al., Gene 91 (1990) 293-296], we PCR-amplified two introns from the human RPS24 locus. These then were used as unique nucleic-acid probes to isolate a 12-kb RPS24 gene fragment from a library of human genomic DNA. The nucleotide sequence of human RPS24 (4942 bp), its exon-intron organization and mRNA transcription start point were determined using standard procedures. RT-PCR analyses of S24 mRNAs from multiple human tissues and cell lines revealed two mRNA isoforms which differ from each other, as well as murine S24 mRNAs due to alternative exon splices near the 3' end of the gene.

Induction of macrophage inflammatory protein 2 gene expression by interleukin 1 beta in rat lung

BACKGROUND

Recruitment of inflammatory cells in the lungs may contribute to tissue injury as a result of mediators released from these cells. Interleukin 1 beta (IL-1 beta) is a potent inducer of neutrophil accumulation, a process that may require local protein biosynthesis. Macrophage inflammatory protein 2 (MIP-2) is a approximately 6 kD heparin binding protein and is a member of the C-X-C superfamily that causes significant neutrophil chemotaxis and activation in vitro. A study was performed to determine whether IL-1 beta could induce the expression of MIP-2 in the lungs of Brown-Norway rats.

METHODS

rhIL-1 beta (500 U) or 0.9% NaCl was injected intratracheally and bronchoalveolar lavage (BAL) cells and lung tissues were evaluated for MIP-2 mRNA expression after RNA extraction by Northern blot analysis. MIP-2 probe was prepared from cDNA obtained by reverse transcriptase-polymerase chain reaction (RT-PCR) of BAL cells obtained from a rat treated with lipopolysaccharide.

RESULTS

There was no detectable MIP-2 mRNA in the lungs of control rats but a marked enhancement of the expression at four hours with no expression at 12 hours and a slight expression at 24 hours. IL-1 beta induced a significant influx of neutrophils into BAL fluid with a transient increase in macrophages. In situ hybridisation of lungs using MIP-2 cDNA probe labelled with digoxigenin showed expression of MIP-2 mRNA in airway mononuclear cells and airway epithelium at four hours after IL-1 beta; at 24 hours the signal had nearly gone.

CONCLUSION

IL-1 beta induces the expression of MIP-2 mRNA in rat lung. MIP-2 may be one chemokine that could contribute to IL-1 beta induced neutrophil influx.

[Study on the characteristics of molecular epidemiology for Salmonella typhi isolated in China. II. Analysis of 16S rRNA gene restriction patterns (16S rRNA GRP) of S. typhi isolated in China]

16S rRNA gene, a highly conservative gene in molecular evolution, was labeled with digoxigenin-11-dUTP by PCR. Using it as a probe, we investigated the 16S rRNA gene restriction patterns (16S rRNA GRP) of S. typhi after their chromosomes were digested with Pst I. Results show that the Pst I 16S rRNA GRP appears obvious polymorphism in strains of distinctive sources. The fragments containing 16S rRNA gene are sized 7.0-26.5kb in 16S rRNA GRP of Pst I. 119 strains can be divided into 38 ribotypes. Most of the strains causing outbreaks from Dalian in 1990 and strains isolated during the pandemic from Yili, Xinjiang in 1991 have the same ribotype; some ribotypes contain epidemic strains which are from different geographic areas; some strains from sporadic cases have their unique ribotypes. We also find the 16S rRNA GRP with Pst I of S. typhimurium rather different from that of S. typhi. Data from further analysis of Pst I ribotypes by mean-linkage clustering method show that pandemic strains, outbreak strains and epidemic strains cluster at 0.55 in genetic distance; nonepidemic strains and strains from sporadic cases gather to form another cluster at 0.70 in genetic distance. Ribotype of strain 251, which was isolated forman asymptomatic carrier is different from the two clusters. The ribotype of S. typhimurium is apparently far distant, comparing with that of S. typhi.

[The diagnosis and therapy of 6 cases of pulmonary alveolar proteinosis]

6 cases of pulmonary alveolar proteinosis were presented. No symptom or physical finding is specific for diagnosis. The final diagnosis can only be documented by patho-morphological examination. PAS positive alcin blue negative lipoprotein in alveolar spaces is the characteristic finding. By using folley's catheter, the authors developed a modified method for pulmonary lavage, and 3 patients were treated effectively.

[The effects of stimulation of the brain osmoreceptor on the tubular reabsorption of sodium, chloride and potassium in rats]

The tubular reabsorption of sodium, chloride and potassium was studied with micropuncture technique and electron probe X-ray microanalysis before and following intracerebroventricular administration of hypertonic saline (icv. HS) in rats. At the late proximal convoluted tubules, the fractional delivery of sodium increased from 53.0 +/- 2.1% to 66.0 +/- 2.9% (P < 0.01), the fractional delivery of chloride increased from 65.4 +/- 3.4% to 78.2 +/- 3.9% (P < 0.05), but the fractional delivery of potassium and tubular fluid osmolarity were unaltered. At the early distal convoluted tubules, the fractional delivery of sodium increased from 8.2 +/- 0.9% to 13.6 +/- 1.8% (P < 0.05), the fractional delivery of chloride increased from 5.4 +/- 0.8% to 9.5 +/- 1.4% (P < 0.05), the tubular fluid osmolality increased from 139.8 +/- 6.9 mOsm/kg H2O to 181.3 +/- 15.6 mOsm/kg H2O2 whereas fractional delivery of potassium did not show significant change. Under the condition of diuresis provoked by the intravenous administration of furosemide the kaliuresis induced by icv. HS was abolished, while the icv. HS-elicited diuresis and natriuresis remained unaffected. These results indicate that stimulation of the brain osmoreceptor inhibits the proximal tubular reabsorption of sodium chloride which in turn enhances sodium-potassium exchange in the distal tubules and collecting ducts.

[Lack of mutagenicity and teratogenicity of 16-methylene-17 alpha-acetoxy-19-norprogesterone]

16-Methylene-17 alpha-acetoxy-19-norprogesterone (ST-1435) is a new antifertility agent. ST-1435 silastic capsule was implanted sc in the nuchal region of rats on d 6 of gestation at 75, 300, and 600 mg.kg-1. The rats were killed on d 20. In comparison with the control, the treated groups showed no significant differences in maternal body weights, number of corpora lutea, and the development of embryos and fetuses. The number of dead fetuses decreased and live fetuses increased slightly. ST-1435 did not affect the frequency of micronucleated polychromatic erythrocytes, nor induce chromosomal aberrations in cultured CHL cells, or increase the revertants of Salmonella typhimurium TA97, TA98, TA100, and TA102 in Ames test. The results suggested that ST-1435 had neither teratogenicity nor mutagenicity.

Determination of dietary cadmium-induced metallothioneins in rabbit kidneys and cadmium in metallothioneins by anion-exchange high-performance liquid chromatography coupled with graphite furnace atomic absorption spectrometry

A rapid method is described for the determination of dietary cadmium-induced metallothioneins (MTs) in rabbit kidneys by anion-exchange high-performance liquid chromatography. Rabbit kidney MT-I and MT-II were eluted at ca. 15.0 and 18.8 min, respectively, from a DEAE-5PW anion-exchange column with a Tris-HCl buffer (0.01-0.25 M, pH 8.6) and detected by ultraviolet absorbance at 254 nm. A standard calibration curve was constructed using purified standard MT isoforms, which demonstrated an excellent linear correlation between UV absorbance peak heights and the amounts of MT isoforms. Feeding a dose of cadmium for some days resulted in an increase in MT concentrations in rabbit kidneys, but not in the livers. The cadmium concentrations in MT-I and MT-II elutions were determined by graphite furnace atomic absorption spectrometry. MT-I and MT-II showed some differences associated with the oral intake of cadmium. Dietary cadmium also caused zinc to accumulate in kidneys to some extent. The effects of dietary oleic acid on the synthesis of MTs were also studied. Based on the method of standard additions, the recovery of MTs exceeded 93% and replicated injection of samples yielded a relative standard deviation of 2.4% at an MT level of 280 micrograms/g.

Analysis of mutagenic nitroarenes in carbon black by high-performance liquid chromatography

A method was developed for the analysis of mutagenic nitroarenes in carbon black. The procedure included extraction, pre-separation column chromatography on silica gel, and determination by high-performance liquid chromatography (HPLC) using a diode-array detector. Different solvents, such as dichloromethane, benzene, toluene, and chlorobenzene were used for the extraction of carbon black. It was found that chlorobenzene yielded the highest amount of extracted material. The pre-separation, the optimization of the HPLC separation, the selection of detection wavelengths, and the calibration curve are discussed. 3-Nitro-9-fluorenone was detected in a treated carbon black, which is used for making carbon ink. The identification of peaks in the sample chromatograms was confirmed by comparing the retention time and the UV spectra with those of standards.