[Diagnostic values of nuclear score combined with cyclin D1 immunocytochemistry in indeterminate thyroid follicular nodules in preoperative fine needle aspiration]

Objective: To assess the feasibility of nuclear score combined with cyclin D1 immunocytochemistry in classifying indeterminate thyroid nodules with fine-needle aspiration (FNA) cytological diagnosis of Bethesda category Ⅲ-Ⅴ. Methods: A consecutive cohort of 118 thyroid FNA specimens with indeterminate diagnosis (TBSRTC category Ⅲ-Ⅴ) and available histopathologic follow-up data were collected between December 2018 and April 2022 at the Department of Pathology, Beijing Hospital, China. These cases were subjected to cytological evaluation and cyclin D1 immunocytochemistry. The optimal cut-off points of a simplified nuclear score and the percentage of cyclin D1-positive cells for the diagnosis of malignancy or low-risk neoplasm were determined using the receiver operating characteristic (ROC) curves and area under the ROC curve (AUC). The specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of nuclear score and cyclin D1 immunostaining were evaluated from the crosstabs based on cut-off points. The diagnostic accuracy of simplified nuclear score combined with cyclin D1 immunostaining was estimated using ROC curve analysis. Results: Nuclear grooves, intra-nuclear inclusions and chromatin clearing were more commonly found in malignancy/low-risk neoplasms than benign lesions (P=0.001, P=0.012 and P=0.001 respectively). A cut-off point of≥2 for the simplified nuclear score was sensitive for defining malignancy/low-risk neoplasm, and its PPV, NPV, sensitivity and specificity were 93.6%, 87.5%, 99.0% and 50.0% respectively. A positive cut-off point of 10% positive thyroid cells in cyclin D1 immunostaining demonstrated sensitivity of 88.5%, specificity of 100%, PPV of 100% and NPV of 53.8% for correctly detecting thyroid malignancy or low-risk neoplasm. The sensitivity and PPV of simplified nuclear score combined with cyclin D1 immunostaining were 93.3% and 100%, respectively. Both specificity and NPV were maintained at high levels (100% and 66.7%, respectively). The diagnostic accuracy of simplified nuclear score combined with cyclin D1 immunostaining in detecting thyroid malignancy/low-risk neoplasm was increased to 94.1% compared to using either of them alone. Conclusions: Combing simplified nuclear score and cyclin D1 immunostaining on FNA cytology specimens can increase the diagnostic accuracy in classifying thyroid nodules of indeterminate cytological categories. Thus, this supplementary approach provides a simple, accurate, and convenient diagnostic method for cytopathologists so that may reduce unnecessary thyroidectomies.

[Diagnostic values of cyclin D1 immunocytochemistry and molecular testing in preoperative fine needle aspiration of undeterminate thyroid nodules]

Objective: To assess the value of cyclin D1 immunocytochemistry combined with a small panel molecular analysis in indeterminate cytological diagnosis of Bethesda category Ⅲ-Ⅴ. Methods: A consecutive cohort of 96 thyroid FNA specimens with indeterminate diagnosis (TBSRTC category Ⅲ-Ⅴ) and available histopathologic follow-up data were collected between December 2018 and December 2021 in Department of Pathology, Beijing Hospital. The cases were evaluated by cyclin D1 immunocytochemistry and molecular testing of BRAF^V600E or a small panel of markers (BRAF, N-RAS, H-RAS, K-RAS and TERT) in the FNA specimens. The identification of the optimal cut-off point of cyclin D1 for the diagnosis of malignancy was evaluated using the receiver operating characteristic (ROC) curves and the assessment of the area under the ROC curve (AUC). The specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of all these markers were evaluated with the crosstabs and significance was calculated. Results: Ninty-six patients with 96 thyroid nodules were enrolled, including 42 cases of TBSRTC-III, 10 cases of TBSRTC-IV and 44 cases of TBSRTC-V. There were 79 females and 17 males with a median age of 47 years (range, 25 to 75 years). A 7.5% cut-off value for positive cyclin D1 nuclear immunostaining in thyroid cells demonstrated 100% PPV, 57.1% NPV, 81.0% sensitivity and 100% specificity for thyroid malignancy diagnosis. The sensitivity of the BRAF^V600E mutation test or combined with a small panel test alone for thyroid malignancy diagnosis were 65.5% and 69.0% respectively. The sensitivity for thyroid malignancy diagnosis increased to 94.0% and 95.2% respectively when combining the cyclin D1 immunocytochemistry with the molecular test, and the specificities remained 100% and 91.7% respectively.The accuracy of cyclin D1 immunocytochemistry combined with a small panel of molecular test in detecting thyroid malignancy increased to 94.8% compared to using these markers alone. Conclusions: The addition of cyclin D1 immunocytochemistry and a small panel of molecular testing to FNA cytology can increase the sensitivity and NPV of cytology in indeterminate categories, and this supplementary approach provides a simple, accurate and convenient diagnostic method for reducing unnecessary thyroidectomies.

[Effects of PI3Kδ-RhoA pathway on phagocytosis defect of alveolar macrophages in a mouse model of chronic obstructive pulmonary disease]

Objective: To investigate effects of Phosphoinositide3-Kinases (PI3Kδ)-Ras homolog gene family member A(RhoA) pathway on phagocytosis deficiency of alveolar macrophages (AMs) in a mouse model of chronic obstructive pulmonary disease (COPD). Methods: Twenty mice were exposed to cigarette smoking to establish the COPD model, with 20 mice as the control group. AMs were isolated from lung tissue by discontinuous density gradient centrifugation and then divided into a healthy control group, a COPD group, a healthy IC87114 group and a COPD IC87114 group. The culture of IC87114 group was mixed with a final concentration of 1 nmol/L IC87114 for 24 hours. Mean fluorescence intensity (MFI) and the positive percent of AMs engulfing flurescein isothiocyanate-labeled Escherichina coli (FITC-E.coli) (AM%) were detected by flow cytometry. Real-Time PCR(RT-PCR)and Western blot were applied to detect mRNA and protein. G-LISA RhoA Kit was used to detect the activity of RhoA, and laser scanning confocal microscopy was used to observe the cytoskeleton structure of AMs. Results: Phagocytosis of AM: MFI and AM %in the COPD group [(4 512±517), (32.2±4.6)%] were decreased than those in the healthy control group [(9 857±1 042), (68.0±4.0)%, all P<0.01]. Compared with the COPD group, MFI and AM% in the COPD IC87114 group [(6 894±472), (50.6±2.1)%] were increased (all P<0.01). The expressions of mRNA and protein of PI3Kδ in the COPD group (3.14±0.54, 0.84±0.08) were increased than those in the healthy control group (1.00±0.00, 0.57±0.07) (all P<0.01). Compared with the COPD group, the expressions of mRNA and protein of PI3Kδ in the COPD IC87114 group (1.52±0.28, 0.66±0.13) were decreased (all P<0.01). The RhoA mRNA, protein and activity in the COPD group (0.70±0.07, 0.41±0.10, 0.70±0.06) were decreased compared to those in the healthy control group (1.00±0.00, 0.56±0.09, 1.19±0.09) (all P<0.01). Compared with the COPD group, the expression of mRNA, protein and activity of RhoA in the COPD IC87114 group(0.91±0.08, 0.48±0.06, 0.86±0.06) were increased (P<0.01, P<0.05). Cytoskeleton of AM: The pseudopods of the healthy control group and the healthy IC87114 group extended well, and the ability of phagocytosing FITC-E.coli was intact, but there were some defects in the COPD group. Compared with the COPD group, the COPD IC87114 group was better, both in phagocytosing and extending of pseudopods. Negative correlations existed between the mRNA, protein of PI3Kδ with mRNA, protein and activity of RhoA. Negative correlations also existed between the mRNA, protein of PI3Kδ with MFI, but positive correlations between RhoA and MFI were observed in all groups. Conclusion: The phagocytosis of AMs in COPD mice was defective, with abnormal rearrangement of the cytoskeleton. PI3Kδ negatively regulated RhoA, while PI3Kδ over activation resulted in decreasing activity of RhoA and then induced abnormal cytoskeleton rearrangement in AMs, which led to phagocytosis deficiency.IC87114 inhibited PI3Kδ activation, improved the activity of RhoA and partly recovered phagocytosis of AMs.

[Mechanisms of cytoskeleton and PI3Kδ-RhoA in fine particulate matter deteriorating phagocytosis defect of alveolar macrophage in mice with chronic obstructive pulmonary disease]

Objective: To explore the mechanism of cytoskeleton and PI3Kδ-RhoA in fine particulate matter deteriorating phagocytosis defect of alveolar macrophage (AM) in chronic obstructive pulmonary disease (COPD) mice. Methods: Forty mice were randomly divided into four groups: health control group, COPD group, health PM2.5 group, COPD PM2.5 group and with ten in each group. A mouse model of COPD was established by cigarette smoke exposure, and health PM2.5 group and COPD PM2.5 group mice were given PM2.5 (588 μg/m(3)) aerosol inhalation for 90 days. AM were isolated from lung tissue by discontinuous density gradient centrifugation. Mean fluorescence intensity (MFI) and the percent of alveolar macrophage engulfing flurescein isothiocyanate-labeled Escherichia coli (FITC-E.coli) AM (AM%) were detected by flow cytometry. The mRNA and protein expression were measured by real time polymerase chain reaction (RT-PCR) and Western blot. The activity of RhoA was measured by GTPase linked immunosorbent assay (G-LISA) Kit. Cytoskeleton was observed by laser scanning confocal microscopy. Results: The MFI and the AM% in COPD group [4 512±517, (32.19±4.57)%] and health PM2.5 group [7 631±585, (50.78±4.58)%] were significantly lower than those in health control group [9 857±1 042, (68.53±2.88)%], while those in COPD PM2.5 group [3 121±393, (21.90±2.58)%] were lower than those in COPD group (all P<0.01). The mRNA and protein of PI3Kδ in COPD group (3.41±0.54, 0.84±0.08)and health PM2.5 group (1.52±0.35, 0.71±0.11) were higher than those in health control group (1.00±0.00, 0.57±0.07) (all P<0.05), and in COPD PM2.5 group (5.53±0.42, 1.17±0.25), the above parameters were remarkably increased as compared to those in COPD group (all P<0.01). The mRNA, protein and activity of RhoA in COPD group (0.70±0.07, 0.41±0.10, 0.70±0.06) and health PM2.5 group (0.84±0.06, 0.46±0.11, 0.87±0.07) were lower than those in health control group (1.00±0.00, 0.56±0.09, 1.19±0.09) (all P<0.05), and above parameters of COPD PM2.5 group (0.42±0.05, 0.31±0.06, 0.44±0.04) were significantly lower than COPD group (all P<0.01). Cytoskeleton of AM: long and dense filopodia and membrane fold could been seen clearly around the AM of health control group; in COPD group and health PM2.5 group, short and sparse filopodia and slightly deformed AM can been seen. Filopodia remarkably decreased and rigid cells with impaired capacity of engulfing FITC-E.coli can be generally observed in COPD PM2.5 group. Negative correlations were existed between PI3Kδ mRNA, protein and RhoA mRNA, protein, activity in all groups (all P<0.01). Negative correlations were existed between PI3Kδ mRNA, protein and MFI, and positive correlations were existed between RhoA mRNA, protein, activity and MFI in all groups (all P<0.05). Conclusion: Fine particulate matter (PM2.5) can deteriorate the phagocytosis of AM from COPD mice through over activating PI3Kδ and inhibiting the activity of RhoA then causing cytoskeleton abnormal rearrangement.

[Cytology of basaloid squamous cell carcinoma and small cell carcinoma of lung: a comparative study]

OBJECTIVE

To evaluate the roles of cytomorphology and immunohistochemistry in distinguishing between basaloid squamous cell carcinoma (BSC) and small cell carcinoma (SCC) of lung.

METHODS

The direct smears and/or liquid-based cytology preparation (ThinPrep) of bronchial brushing/washing and fine-needle aspiration (FNA) specimens from 17 cases of biopsy-proven BSC of lung were retrospectively reviewed and compared with those from 17 cases of SCC. The cytomorphologic parameters analyzed included proportion of cohesive cell clusters, cell palisades/rosettes, adenoid cystic features, crushing artifact, nuclear maximum diameter, nuclear molding, scantiness of cytoplasm,"salt-and-pepper"nuclei, distinct nucleoli, spindly configuration, individual cell keratinization, necrosis, hyaline material, apoptosis and mitotic activity. Immunocytochemical/immunohistochemical study of 25 cases was performed. Ten FNA samples of basaloid squamous cell carcinoma were also analyzed for epidermal growth factor receptor mutations in exons 18, 19, 20 and 21 using amplification refractory mutation system.

RESULTS

Most of the 17 BSC cases (15/17) showed a predominance of tightly cohesive tumor cell clusters. The proportion of isolated tumor cells was high in SCC (more than 60% in 14 cases). The nuclear maximum diameter of BSC was slightly larger than that of SCC (9 to 11 μm in BSC versus 7 to 9 μm in SCC)."Salt-in-pepper"nuclei, nuclear molding and crushing artifact were detected in all SCC cases (15/17, 17/17 and 14/17, respectively). These features were only occasionally found in BSC group. Nucleoli were present in BSC and rarely (2/17) in SCC. Only 9 of 17 BSC cases showed individual cell keratinization. The differences in the above-mentioned cytomorphologic features were statistically significance (P<0.05). The results of immunohistochemistry performed on the cell block sections and immunocytochemistry performed on the ThinPrep slides were identical to that performed on the corresponding biopsy specimens. The tumor cells in BSC were consistently positive for CK5, p40 and p63. TTF1, chromogranin A, synaptophysin and CD56 were positive in most of SCC. One of SCC cases showed focal PAX5 expression. No EGFR mutations were detected in the 10 BSC cases studied.

CONCLUSIONS

Selected cytomorphologic features, including presence of cohesive cell clusters, larger nuclear size, distinct nucleoli, lack of crushing artifact, absence of nuclear molding and presence of individual cell keratinization, are helpful in diagnosing BSC on cytology specimens. Immunohistochemistry using a panel of TTF1, CK5, p40/p63 and chromogranin A/synaptophysin/CD56 provides further clues in differential diagnosis between BSC and SCC. EGFR mutation study is often negative in lung BSC.

[Clinicopathological diagnosis of diffuse alveolar hemorrhage]

OBJECTIVE

To improve knowledge about the clinical and pathological features of diffuse alveolar hemorrhage (DAH).

METHODS

Six cases DAH with intact clinical and pathological data were retrospectively analyzed during the period from May 1999 to May 2015 in Beijing Hospital. There were altogether 2 males and 4 females, with age ranging from 32 to 68 years (mean 58.8 years). Specimens were obtained by autopsy (3 cases), open lung biopsy (2 cases) and renal biopsy (2 cases), including 1 case of open lung biopsy in 2003, renal biopsy in 2012.

RESULTS

Clinically, the patients presented with cough, shortness of breath and dyspnea, including 5 cases of hemoptysis, 4 cases of fever, 3 cases of skin and mucosa bleeding, 2 cases of gross hematuria, 2 cases of microscopic hematuria, 3 cases of renal functional impairment. A total of 5 cases had different levels of elevated erythrocyte sedimentation rate and C-reactive protein, 6 cases had moderate anemia, hypoxemia, diffuse infiltrates with alveolar filling in chest CT. Serum antineutrophil cytoplasmic antibody was positive in 3 cases, anti-glomerular basement membrane antibody was present in 1 case. Pathological diagnosis: 2 cases of Granulomatosis with polyangiitis (GPA), 2 cases of Microscopic polyangiitis (MPA), 1 case of Goodpasture syndrome, 1 case of pulmonary veno-occlusive disease (PVOD).

PROGNOSIS

3 cases died; 2 cases were discharged; 1 case received symptomatic treatment, follow-up after discharge.

CONCLUSION

The mainly clinical characteristics of DAH are varied degree of dyspnea, anemia, hypoxemia, and extensive ground-glass opacification or consolidation in image, with or without haemoptysis; diffuse acute or chronic pulmonary hemorrhage in lung tissue is the main pathological feature.

The heterogeneous nuclear ribonucleoprotein K (hnRNP K) interacts with dengue virus core protein

Heterogeneous nuclear ribonucleoprotein K (hnRNP K), a component of hnRNP particles, is involved in several steps of gene expression regulation. Dengue (DEN) virus, a member of the Flaviviridae, is the primary cause of illnesses such as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. In mature DEN virus particles, the core protein is a structural protein that forms a nucleocapsid complex with genomic RNA. Very little of its biologic functions is known. Here, using an in vitro binding assay and coimmunoprecipitation analysis, we report a protein-protein interaction between the DEN virus core protein and hnRNP K. The C-terminal hydrophilic region of the DEN virus core protein, spanning amino acid residues 73 to 100, is required for such interaction. Results of glutathione-S transferase binding assays indicated that the core protein-hnRNP K interaction might be abolished in the presence of hnRNP K cognate nucleic acids. Furthermore, in a cotransfection experiment, the repressive effect of hnRNP K on C/EBPbeta-mediated transcription activation could be reversed by full-length DEN virus core protein but not by a truncated form containing amino acids 1-72. Our results suggest that, on DEN virus infection, the multiple functions of cellular hnRNP K may be affected by the virus core protein.

Negative regulation of IS2 transposition by the cyclic AMP (cAMP)-cAMP receptor protein complex

Three sequences similar to that of the consensus binding sequence of the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex were found in the major IS2 promoter region. Experiments were performed to determine whether the cAMP-CRP complex plays a role in the regulation of IS2 transposition. In the gel retardation assay, the cAMP-CRP complex was found to be able to bind the major IS2 promoter. A DNA footprinting assay confirmed that the cAMP-CRP complex binds to the sequences mentioned above. With an IS2 promoter-luciferase gene fusion construct, the cAMP-CRP complex was shown to inhibit transcription from the major IS2 promoter. IS2 was found to transpose at a frequency approximately 200-fold higher in an Escherichia coli host defective for CRP or adenyl cyclase than in a wild-type host. These results suggest that the cAMP-CRP complex is a negative regulator of IS2 transposition.

Functional domains of the InsA protein of IS2

The InsA protein is a transcriptional regulator. It binds to the promoter region of insA and insAB'. To understand the molecular mechanism for the interaction between InsA and its binding sequence, the functional domains of InsA were identified. The glutaraldehyde cross-linking method and the two-hybrid expression system were used to study the protein-protein interaction of InsA. The results of these experiments showed that InsA forms homodimers. Deletion of the last 44 amino acid residues at its C terminus, but not the first 12 or 57 residues at the N terminus, abolished the ability of InsA to form homodimers, indicating that the protein-protein interaction domain of InsA is located at its C terminus. Gel retardation assays revealed that deletion of the last 29 amino acid residues at its C terminus had no effect on the DNA binding ability of InsA. In contrast, deletion of the first N-terminal 12 residues abolished the DNA binding capability of InsA. These results indicate that the DNA binding domain of InsA is located at its N terminus.

Detection of an IS2-encoded 46-kilodalton protein capable of binding terminal repeats of IS2

The genome of the transposable element IS2 contains five open reading frames that are capable of encoding proteins greater than 50 amino acids; however, only one IS2 protein of 14 kDa had been detected. By replacing the major IS2 promoter located in the right terminal repeat of IS2 with the T7 promoter to express IS2 genes, we have detected another IS2 protein of 46 kDa. This 46-kDa protein was designated InsAB'. Analyses of the InsAB' sequence revealed motifs that are characteristic of transposases of other transposable elements. InsAB' has the ability to bind both terminal repeat sequences of IS2. It was shown to bind a 27-bp sequence (5'-GTTAAGTGATAACAGATGTCTGGAAAT-3', positions 1316 to 1290 by our numbering system [16 to 42 by the previous numbering system]) located at the inner end of the right terminal repeat and a 31-bp sequence (5'-TTATTTAAGTGATATTGGTTGTCTGGAGATT-3', positions 46 to 16 [1286 to 1316]), including the last 27 bp of the inner end and the adjacent 4 bp of the left terminal repeat of IS2. This result suggests that InsAB' is a transposase of IS2. Since there is no open reading frame capable of encoding a 46-kDa protein in the entire IS2 genome, this 46-kDa protein is probably produced by a translational frameshifting mechanism.

Isolation and identification of influenza viruses from clinical materials in 1977-1993 at Veterans General Hospital-Taipei

From 1977 to 1993, 15,189 throat swab samples were received for isolation and identification of influenza virus in the Clinical Virology Laboratory, Veterans General Hospital-Taipei. Most of the samples came from the Pediatric Department. There were 634 identified strains of the influenza virus; the successful isolation rate was 4.17% in average/year. Among these isolates, 56.3% (357/634) were influenza B; 12.1% (77/634) were influenza A/H1N1 and 28.1% (178/634) were influenza A/H3N2. About 3.5% (22/634) were classified as flu-like agents because of no reaction with available monoclonal antibodies. In recent years, reverse transcriptase polymerase chain reaction (RT-PCR) was established here to re-evaluate these virus stocks. This method can provide rapid diagnosis method to identify influenza A/H1N1, A/H3N2 and B. Further, the RT-PCR method and sequencing of amplified DNA could be used to see the variation of virus isolates which were recirculated or which reappeared in the Taipei area.

Gene for cytochrome c oxidase subunit II in the mitochondrial DNA of Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae)

The cytochrome c oxidase subunit II (COII) gene between transfer RNA for Leu and Lys in the mitochondrial DNA of Culex quinquefasciatus Say and Aedes aegypti (L.) was amplified by the polymerase chain reaction (PCR) technique. Both the gene order and direction of transcription were identical to Anopheles and Drosophila. Nucleotide sequences of the PCR-amplified COII genes in these two mosquitoes exhibited 88% homology, and the frequency of transition was very close to that of transversion. The homology of deduced amino acid sequences of COII between these two mosquitoes was 95%. Two highly conserved segments of COII proteins were found in mosquitoes, fruit flies, locust, and honeybee. These segments contain the major amino acid residues of cytochrome c oxidase involved in electron transport and ligand binding. The amino acid residues are located at the positions similar to those of the mammalian enzymes. Two sets of the phylogenetic trees of a similar pattern were generated by comparing the divergences of nucleotide and amino acid sequences of COII. The branch lengths of the trees estimated by amino acid and nucleotide sequences showed different evolution rates of Aedes and Culex from their common ancestor.

Functional analysis of the 14 kDa protein of insertion sequence 2

The IS2 sequence encodes five open reading frames (ORF1 to ORF5) that are greater than 150 nucleotides each. Only one protein of 14 kDa was detected when the expression of IS2 genes was examined in minicells. This 14 kDa protein was referred to as InsA in this study and was determined to be encoded by ORF1. A sixfold decrease in IS2 transposition frequency was observed when insA was overexpressed. DNA footprinting results indicated that InsA binds to the sequence 5'-TAAATAA-3' located at IS2 nucleotide numbers 1286 to 1292. (The IS2 right terminal repeat spans nucleotides 1290 to 1331.) This InsA binding sequence is situated 4 bp upstream from the putative "-10" sequence of the insA promoter that overlaps the right terminal repeat of IS2. The presence of a promoter located in this region was demonstrated by the ability of a DNA fragment containing the right terminal repeat to drive the expression of a promoterless lacZ gene. The transcription of insA was determined to start at the A residue located at nucleotide number 1268. With the same insA promoter-lacZ fusion construct, overexpression of insA in the same cell was found to decrease the beta-galactosidase activity. The results of this study suggest that InsA affects IS2 transposition by regulating the transcription of IS2 genes.

Carpal bone dislocations: an analysis of twenty cases with relative emphasis on the role of crushing mechanisms

Twenty cases of carpal bone dislocation were encountered during a 7-year period, with an average of 27 months of follow-up. There were ten types of dislocation in this series; the most common type was transscaphoid perilunate dislocation which was seen in nine cases. In addition, there were two scaphoid subluxations; one volar lunate dislocation; one dorsal perilunate dislocation; one scaphoid perilunate dislocation; one hamate and pisiform dislocation; one transhamate pisiform dislocation; one trapezoid dislocation with dislocation of carpometacarpal joints two to five; one dislocation of the trapezium, trapezoid, and carpometacarpal joints two to four; and two trapezium periscapholunate dislocations. Methods of treatment included open reduction, closed reduction, proximal row carpectomy, total wrist arthrodesis, and excision of the lunate. In this series, the patterns of dislocation were different for crushing injuries and dorsiflexion injuries. The clinical results associated with the soft-tissue injuries of the ipsilateral hand were mostly caused by crushing forces. Although carpal instabilities were noted, there was no significant correlation between the clinical and roentgenographic results in some of our cases. Best results invariably relied on a stable anatomic reduction and an adequate period of immobilization. Poor results were demonstrated in the cases with incomplete initial reduction, secondary degenerative arthrosis, or nonunion.

[Change in calcium transport as a factor in causing dysfunction of myocardial mitochondria during hypoxia]

During normoxic incubation of isolated myocardial mitochondria, there were marked increases in mitochondrial calcium when free calcium concentration in the incubation medium was enhanced. The increases were concomitant with rises increase in the rate of state 4 respiration. Moreover, there is a positive correlation between the mitochondrial calcium and the rate of state 4 respiration. During hypoxic incubation, when the calcium concentration of the incubation medium was enhanced, there was no significant increase in mitochondrial calcium and the rises in the rate of state 4 respiration were much lower than the rises during normoxia. Hypoxic incubation in medium of low calcium concentration (pCa 8.0) resulted in slight rises in rate of state 4 respiration. The above results suggest that in myocytes, the mitochondrial dysfunction under hypoxia may be caused indirectly by changes in cytoplasm rather than directly by hypoxia. It seems that the change of cellular free calcium concentration is an important factor in the mitochondrial dysfunction.

Rhodostomin, an RGD-containing peptide expressed from a synthetic gene in Escherichia coli, facilitates the attachment of human hepatoma cells

Rhodostomin (Rho) from snake venom, a potent inhibitor of platelet aggregation, contains 68 amino acids having an RGD sequence and 12 cysteine residues. A chemically synthesized Rho gene was cloned and expressed in Escherichia coli. The expression of Rho gene fused with the glutathione S-transferase (GST) gene was about 10-30% of total cell proteins. The Rho-fusion protein could be recognized by antibodies raised against either a native Rho peptide or a synthetic peptide. The purified GST-Rho coated on culture plates facilitated the attachment of human hepatoma cells, which was inhibitable by co-incubation with a synthetic hexapeptide GRGDSP but not with a related peptide of GRGESP, suggesting that the E. coli-expressed Rho-fusion protein was properly folded and biologically functional.

[Relationship between central beta-endorphins and serotonin systems in mechanism of hypoxic ventilatory regulation]

Experiments were performed on anesthetized bilaterally chemodenervated rabbits. After giving hypoxic gas mixture (10% O2 in N2) to animals to cause ventilatory inhibition, lateral ventricle applications of beta-endorphins (beta-EP) antagonist naloxone (Nlx) and agonist ohmefentanyl (OMF) respectively reduced and enhanced hypoxia-induced ventilatory inhibition. Meanwhile the level of central serotonin (5-HT) was obviously increased more than that before the drug administration. Injection of exogenous 5-HT into rabbit lateral ventricle induced central beta-EP content to decrease markedly while minute ventilation (VE) was returned to control at the same time. The results suggest that beta-EP system in CNS is the basic and direct element in the regulatory mechanism of hypoxic ventilatory inhibition, and central 5-HT system only acts as a neuromodulator in modulating the activity of beta-EP system to indirectly affect ventilatory response to hypoxia.

Withdrawal of immunosuppressive therapy in allogeneic bone marrow transplantation reactivates chronic viral hepatitis C

A 28-year-old female patient with acute myelogenous leukemia and post-transfusion chronic viral hepatitis C received an allogeneic bone marrow transplantation (BMT) in first complete remission. The inflammatory activity of chronic hepatitis C decreased dramatically with the start of BMT and during the whole course of cyclosporin A treatment. After the immunosuppressive therapy was stopped, however, the chronic hepatitis C activity increased and the serum alanine amino-transferase levels thereafter remained as high as before BMT. Hepatitis C virus RNA was detected by polymerase chain reaction in serum drawn 60 days and 52 months after BMT. Since fulminant viral hepatitis B may take place after tapering of immunosuppressive therapy following BMT due to an excessive response of recovering immunity to the actively replicating virus during immune suppression, careful monitoring of liver function for patients with chronic viral hepatitis C in BMT is suggested.

Carpal bone dislocations: review of 20 cases

Twenty cases of carpal bone dislocation were encountered during a 7-year period, with an average of 27 months of follow-up. There were 10 types of dislocation in this series, the most common type was transscaphoid perilunate dislocation seen in 9 cases. In addition, there were 2 scaphoid subluxations, 1 volar lunate dislocation, 1 dorsal perilunate dislocation, 1 scaphoid perilunate dislocation, 1 hamate and pisiform dislocation, 1 transhamate pisiform dislocation, 1 trapezoid and 2-5 carpometacarpal joint dislocation, 1 trapezium, trapezoid and 2-4 carpometacarpal joint dislocation, and 2 trapezium periscapholunate dislocations. Methods of treatment included open reduction, closed reduction, proximal row carpectomy, total wrist arthrodesis, and excision of the lunate. In this series, the patterns of dislocation were different for crushing injuries and dorsiflexion injuries. The clinical results associated with the soft tissue injuries of the ipsilateral hand were mostly caused by crushing forces. Although carpal instabilities were noted, there was no significant correlation between the clinical and radiographic results in some of our cases. Best results invariably relied on a stable anatomic reduction and an adequate period of immobilization. Poor results were demonstrated in those cases with incomplete initial reduction, secondary degenerative arthrosis, or nonunion.

[Cloning and sequencing of hemolysin gene from clinical Aeromonas hydrophila]

Aerolysin is one of the important virulence factors for Aeromonas hydrophila infection. To understand the characteristics of the aerolysin gene in clinical A. hydrophila, a genomic library was constructed by using pUC19 as cloning vector. The positive clone containing the aerolysin gene was selected by the colony hybridization method, using the aerolysin probe (an 48 mer oligonucleotide) of aquatic A. hydrophila. Four positive out of 1,200 transformants were obtained from the primarily screened genomic library, and were further identified for specific binding capability by the dot blot hybridization method. One of three positive clones, designated as pAH-1, was further analyzed by the restriction mapping technique. For further sequencing the aerolysin gene nucleotides, the 3.0 kb fragment of A. hydrophila isolated from pAH-1 was cloned into pBluescriptII, pKS+, resulting in plasmid pKAH-1. Subclones of pKAH-1 were constructed and determined for the presence of 48 mer aerolysin gene sequence by dot blot hybridization method. These (subclones pKS+SS and pSK+SS) were selected for nucleotide sequencing by single-stranded dideoxy sequencing method. The nucleotide sequence similarity coefficient between clinical and aquatic strains of A. hydrophila was 76%; whereas between clinical strains of A. hydrophila and A. sobria was 71%. Since the length of the A. hydrophila DNA fragment cloned into pAH-1 is 3.0 kb, a larger size than the aerolysin gene of aquatic A. hydrophila (1.45 kb) and, also, includes 3' region of aerolysin gene in aquatic A. hydrophila, the indication is that the clone, pKAH-1, contains an entire aerolysin gene of A. hydrophila. The similarity between a small region (containing 8 amino acids) of the aerolysin in the clinical A. hydrophila and the alpha toxin of Staphylococcus aureus suggests that there is functional significance in this region.

Characterization of the transposon carrying the STII gene of enterotoxigenic Escherichia coli

The Escherichia coli enterotoxin STII gene is carried by Tn4521. The terminal repeats of Tn4521 are composed of IS2 sequences; however, neither repeat is a complete IS2. In order to determine how this seemingly defective transposon could transpose, mutations were generated within Tn4521 to determine the regions essential for transposition. The left terminal repeat region was found to be non-essential, but the right terminal repeat area was demonstrated to be crucial for transposition. Within the right terminal repeat area is an open reading frame (ORF), capable of encoding a 159 amino acid protein, which was shown by frameshift mutation analysis to be required for transposition. This protein may be the transposase of Tn4521. A pair of 11 bp repeat sequences flanking the ORF was also pair of 11 bp repeat sequences flanking the ORF was also found to be important. The right 11 bp repeat is part of the left IS2 terminal sequence, and the left 11 bp repeat is located about 300 bp upstream from the right IS2 terminal sequence located within the right terminal repeat region. The results of this study suggest that Tn4521 is a functional transposon and that the sequence including this pair of 11 bp sequences plus the intervening sequence is a transposable element which may be responsible for Tn4521 transposition.

Characterization of the terminal sequences flanking the transposon that carries the Escherichia coli enterotoxin STII gene

The Escherichia coli enterotoxin STII gene is flanked by two repeat sequences, approx. 600 bp each and 8 kb apart. This 9-kb DNA fragment has been shown to transpose as a unit and is thus considered a transposon. It is presently designated as Tn4521. In this study, the two terminal sequences of Tn4521 cloned in pPS1 were localized, isolated, and characterized. The two terminal sequences were found to be composed of IS2 sequences and were in an inverted repeat orientation. However, neither repeat contained a complete IS2. The LTR contained bp 1-722, whereas the RTR contained bp 17-536 and 969-1327, all three of the IS2 sequence.