Effects of feeding fatty acid calcium and the interaction of forage quality on production performance and biochemical indexes in early lactation cow

Multiparous early lactation Holstein cows (n = 16) were used in a randomized complete block design to determine the effects of feeding fatty acid calcium and the interaction of forage quality on production performance and biochemical indexes in early lactation cow. Treatments were as follows: (i) feeding low-quality forage without supplying fatty acid calcium (Diet A), (ii) feeding low-quality forage with supplying 400 g fatty acid calcium (Diet B), (iii) feeding high-quality forage without supplying fatty acid calcium (Diet C) and (iv) feeding high-quality forage with supplying 400 g fatty acid calcium. This experiment consisted 30 days. The milk and blood samples were collected in the last day of the trail. Intakes were recorded in the last 2 days of the trail. Supplementation of fatty acid calcium decreased significantly dry matter intake (DMI) (p < 0.01). Addition fatty acid calcium decreased milk protein percentage (p < 0.01) and milk SNF percentage (p < 0.01), but increased MUN (p < 0.05). Supplemented fatty acid decreased concentration of blood BHBA (p < 0.05), but increased TG, NEFA, glucagon, GLP-1, CCK, leptin, ApoA-IV, serotonin and MSH concentration in blood, the CCK concentration and feed intake showed a significant negative correlation (p < 0.05).

Expression and diagnostic implications of carbonic anhydrase IX in several tumours with predominantly clear cell morphology

AIMS

High expression of carbonic anhydrase IX (CA IX) has been reported in clear cell renal cell carcinoma (ccRCC); few studies have reported CA IX expression in other tumours with predominantly clear cell morphology. The aim of study was to examine the expression and diagnostic implications of CA IX in these latter tumours.

METHODS AND RESULTS

An immunohistochemical study was performed of 159 tumours with predominantly clear cell morphology. The results showed that, in addition to primary (25/25) and metastatic (10/11) ccRCC, CA IX was also expressed in breast (2/2), pulmonary (3/5) and hepatic (1/4) clear cell carcinoma, urothelial carcinoma with clear cell change (3/6), clear cell meningioma (4/6) and ependymoma (2/3), haemangioblastoma (10/10), and clear cell hidradenoma (5/6). However, while strong and diffuse positivity for CA IX was observed in ccRCC, clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma, the other cases showed predominantly focal positivity for CA IX. In particular, CA IX staining was often seen at the periphery of necrotic areas.

CONCLUSIONS

Our results indicate that strong and diffuse CA IX expression may be useful for differentiating ccRCC from several clear cell tumours, with the exception of clear cell breast carcinoma, haemangioblastoma, and clear cell hidradenoma.

Mesothelioma of the tunica vaginalis testis with prominent adenomatoid features: a case report

Malignant mesotheliomas of the testis arise from the tunica vaginalis, formed from the evagination of the abdominal peritoneum into the scrotum. It is an extremely rare tumor representing 0.3% to 5% of all malignant mesotheliomas. We presented an interesting case of 68-year-old male with swelling and slightly painful in the right scrotum. Histologically, the lesion were composed of small tubular, microcystic, gland lined by flattened epithelioid cells and vague signet ring cells set in a myxofibrous stroma, which is resemblance to adenomatoid tumor. But the tumor cells showed significant atypical cytologic morphology and invaded into spermatic cord tissue, which indicated the diagnosis of malignant tumor. Immunohistochemistry study showed positive expression of CK, CK5/6, CK7, Calretinin, D2-40 and Vimentin which indicated the diagnosis of malignant mesothelioma. This case of mesothelioma should be classified as epithelial in type. To our knowledge, the mesothelioma of the tunica vaginalis testis with adenomatoid tumor-like microscopic features is very rare.

Expression of LATS1 contributes to good prognosis and can negatively regulate YAP oncoprotein in non-small-cell lung cancer

Large tumor suppressor (LATS) is a Ser/Thr kinase originally isolated from Drosophila. Recent studies demonstrate that LATS is an important member of the Hippo pathway which can regulate organ size and cell proliferation. However, little is known about the expression and clinical significance of LATS in lung cancer. In this study, we aimed to assess the clinical significance and biological functions of LATS1 in non-small-cell lung cancer (NSCLC). We investigated the expression of LATS1 in 136 cases of NSCLC tissue and 30 cases of normal lung tissue by immunohistochemical staining. The results confirmed that LATS1 expression was higher in normal lung tissues, but significantly lower in NSCLC tissues. Moreover, the expression of LATS1 in NSCLC was significantly correlated with p-TNM stage (p = 0.038) and lymph node metastasis (p = 0.014). Importantly, the loss of LATS1 expression was associated with short overall survival. Further study in NSCLC cell lines in which LATS1 was either overexpressed or depleted confirmed that LATS1 markedly inhibited cell proliferation and invasion and could regulate the nuclear location of yes-associated protein (YAP). These results indicate that LATS1 may play an important role in NSCLC, and may serve as a novel therapeutic target of NSCLC.

Isoleucine, leucine, methionine, and threonine effects on mammalian target of rapamycin signaling in mammary tissue

Improved representation of postabsorptive N metabolism in lactating dairy cows requires a better understanding of protein synthesis regulation in the mammary glands. This study aimed to determine the quantitative effects of Ile, Leu, Met, and Thr on the phosphorylation state of signaling proteins that regulate protein synthesis. The experiment used a composite design with a central point, 2 axial points per AA, and a complete 2(4) factorial. All of the other AA were provided at the concentrations in Dulbecco's modified Eagle's medium. The experiment was replicated with tissues from 5 lactating cows. Mammary tissue slices (0.12 ± 0.02 g) were incubated for 4h. Total and site-specific phosphorylated mammalian target of rapamycin (mTOR; Ser2448), eukaryotic elongation factor (eEF) 2 (Thr56), ribosomal protein S6 (Ser235/236), and eukaryotic initiation factor 2α (Ser51) were determined by western immunoblotting. Tissue concentrations of the 4 AA studied responded linearly to media supply. Addition of Ile, Leu, Met, or Thr had no effect on eukaryotic initiation factor 2α phosphorylation. Isoleucine and Thr positively affected mTOR phosphorylation. However, the 2 AA had an antagonistic relationship. Similarly, Ile linearly increased ribosomal protein S6 phosphorylation, and Thr inhibited the Ile effect. In addition, eEF2 phosphorylation was linearly decreased by Ile and Leu. Threonine curvilinearly decreased eEF2 phosphorylation, Ile and Leu negatively interacted on eEF2, and Thr tended to inhibit Leu effects on eEF2. This work demonstrated saturable responses and interactions between AA on activation of the mTOR pathway. Incorporation of these concepts into milk protein response models will help to improve milk and milk protein yield predictions and increase postabsorptive N efficiency and reduce N excretion by dairy cows.

Expression of a phosphorylated form of ATF4 in lung and non-small cell lung cancer tissues

ATF4 is a member of the cAMP-responsive element-binding protein family of basic zipper-containing proteins, a family of transcription factors phosphorylated at serines residues by protein kinase A. The family has been proved to be able to stimulate the transcription of the genes containing CRE elements. Elevated ATF4 expression was detected in some tumors including breast carcinoma compared to their corresponding nontumor tissues. p-ATF4 (ser 245), a phosphorylated form of ATF4 protein at serine 245 site, was believed to be an active type of this protein. However, its expression and clinical significance in malignant tumors including non-small cell lung cancer were not reported up to date. In the current study, we investigate the expression of p-ATF4 (ser 245) in non-small cell lung cancer using tissue microarray and immunohistochemistry. p-ATF4 (ser 245) immunostaining was detected in nucleus and cytoplasm in cancer cells and normal lung epithelial cells. Compared to bronchial epithelium and submucosal glands (total positive rate, 14.6% (12/82)), there was increased expression of p-ATF4 (ser 245) in non-small cell lung cancer cells (total positive rate, 42.7% (35/82)) (p < 0.05). In addition, increased expression of p-ATF4 (ser 245) was associated with lymph node metastasis and advanced TNM stages (III and IV) in non-small cell lung cancer (p < 0.05). Immunofluorescent staining confirmed nuclear and cytoplasmic expression of p-ATF4 (ser 245) in lung and cancer tissues, and also in non-small cell lung cancer cell lines including NCI-H157 and LTE cells. These results indicate that increased expression of p-ATF4 (ser 245) may contribute to cancer development of non-small cell lung cancer and may be a potential cancer marker.

A case of adenocarcinoma of the rete testis accompanied by focal adenomatous hyperplasia

Adenocarcinoma of the rete testis is very rare. There is still little knowledge about its etiology and pathogenesis. Herein, we present a case of rete testis adenocarcinoma in a 36-year-old Chinese male. The tumor was predominantly composed of irregular small tubules and papillary structures with cuboidal or polygonal cells. In peripheral area of the tumor, the remaining normal rete testis and adenomatous hyperplasia of the rete testis could also be seen, indicating the possible relationship between adenomatous hyperplasia and adenocarcinoma. In addition, the patient underwent a left hydrocelectomy because of the existence of hydrocele 3 years ago. But, it is unclear whether hydrocele and hydrocelectomy is its cause or just the early clinical presentation of the adenocarcinoma.

Mediastinal epithelioid hemangioendothelioma with abundant spindle cells and osteoclast-like giant cells mimicking malignant fibrous histiocytoma

Abstract

Epithelioid hemangioendothelioma is a relatively uncommon lesion usually presenting in soft tissues. The occurrence in the mediastinum is exceptional rare. Histologically, this tumor is characterized by epithelioid cells with intracytoplasmic vacuoles in a hyalinized or mucinous stroma. Occasionally, spindle cells or osteoclast-like giant cells can be observed. Herein, we present a case of epithelioid hemangioendothelioma in a 38 year-old Chinese male. The tumor was predominantly composed of abundant spindle cells with marked atypia and scattered osteoclast-like giant cells reminiscent of malignant fibrous histiocytoma. The unusual histological appearance can pose a great diagnostic challenge. It may be easily misdiagnosed, especially if the specimen is limited or from fine-needle aspiration.

Virtual slides

http://www.diagnosticpathology.diagnomx.eu/vs/5804918529726307

Endobronchial endometriosis presenting as central-type lung cancer: a case report

Abstract

A 45-year-old female patient was referred to our hospital for complaining of dyspnea and coughing in the past four months. The computed tomography scanning demonstrated a central lesion in the upper lobe of the left lung close to the hilar, and the subsequent bronchoscopy revealed a polypoid lesion of the distal of the left main bronchus. This patient was diagnosed clinically as “possibly central-type lung cancer”. However, the pathologic result of the surgically excised polypoid lesion was endobronchial endometriosis.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1077439085928525

Variable Ki67 proliferative index in 65 cases of nodular fasciitis, compared with fibrosarcoma and fibromatosis

Abstract

Nodular fasciitis is the most common pseudosarcomatous lesion of soft tissue. Ki67 was considered as a useful marker for distinguishing some benign and malignant lesions. To study the usefulness of Ki67 in diagnosis of nodular fasciitis, the expression of Ki67 was examined by using immunostaining in 65 nodular fasciitis specimens, 15 desmoid fibromatosis specimens and 20 fibrosarcoma specimens. The results showed that there was a variable Ki67 index in all 65 cases of nodular fasciitis, and the mean labeling index was 23.71±15.01%. In majority (70.77%) of all cases,the index was ranged from 10% to 50%, in 6.15% (4/65) of cases the higher Ki67 index (over 50%) could be seen. The Ki67 proliferative index was closely related to duration of lesion, but not to age distribution, lesion size, sites of lesions and gender. Moreover, the mean proliferative index in desmoid fibromatosis and fibrosarcoma was 3.20±1.26% and 26.15±3.30% respectively. The mean Ki67 index of nodular fasciitis was not significantly lower than fibrosarcoma, but higher than desmoid fibromatosis. The variable and high Ki67 index in nodular fasciitis may pose a diagnostic challenge. We should not misdiagnose nodular fasciitis as a sarcoma because of its high Ki67 index. The recurrence of nodular fasciitis is rare; and the utility of Ki67 immunostaining may be not suitable for recurrence assessment in nodular fasciitis.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4782335818876666

Sclerosing rhabdomyosarcoma presenting in the masseter muscle: a case report

Abstract

Sclerosing rhabdomyosarcoma (SRMS) is exceedingly rare, and may cause a great diagnostic confusion. Histologically, it is characterized by abundant extracellular hyalinized matrix mimicking primitive chondroid or osteoid tissue. So, it may be easily misdiagnosed as chondrosarcoma, osteosarcoma, angiosarcoma and so on. Herein, we report a case of SRMS occurring in the masseter muscle in a 40-year-old male. The tumor showed a diverse histological pattern. The tumor cells were arranged into nests, cords, pseudovascular, adenoid, microalveoli and even single-file arrays. Immunostaining showed that the tumor was positive for the Vimentin, Desmin and MyoD1, and was negative for CK, P63, NSE, CD45, CD30, S-100, CD99, Myoglobin, CD68, CD34, CD31, and α–SMA. Based on the morphological finding and immunostaining, it was diagnosed as a SRMS. In addition, focally, our case also displayed a cribriform pattern resembling adenoid cystic carcinoma. This may represent a new histological feature which can broaden the histological spectrum of this tumor and also may lead to diagnostic confusion.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1615846455818924

Pulmonary sclerosing hemangioma presenting with dense spindle stroma cells: a potential diagnostic pitfall

Pulmonary sclerosing hemangioma (PSH) is an uncommon pulmonary tumor. Histologically, PSH typically consists of two types of cells, surface cuboidal cells and polygonal cells, four architectural patterns including papillary, sclerotic, solid, and hemorrhagic. Herein, we present a case of PSH in a 59-year-old Chinese female. The tumor was predominantly composed of solid area presenting with diffuse spindle cells rather than polygonal cells. Focally, classical papillary and sclerotic area could be seen. Immunohistochemical staining showed that the spindle cells were positive for TTF-1, EMA, Actin(SM) and Vimentin, and negative for cytokeratin, cytokeratin7, cytokeratin5/6, surfactant apoprotein A, surfactant apoprotein B, CD34, CD99, S-100, HMB45, Desmin, Synaptophysin, CD56, ALK and Calretinin. The immunophenotype of the dense spindle cells in this case was similar to that of the polygonal cells, and thus the spindle cells may be the variants of polygonal cells. Based on morphologic features and the immunohistochemical profile, the tumor was diagnosed as a PSH. The significance of spindle cells change is unclear for us. To our knowledge, this is the first reported case of PSH showing dense spindle cells in solid area. This case represents a potential diagnostic pitfall, as it may be misdiagnosed as a mesenchymal tumor such as inflammatory myofibroblastic tumor, synovial sarcoma, solitary fibrous tumor, leiomyoma, or even mesothelioma, especially if the specimen is limited or from fine- needle aspiration.

A case of enteropathy-associated T-cell lymphoma (type I) arising in stomach without refractory celiac disease

Enteropathy-associated T-cell lymphoma (EATL) is a rare peripheral T-cell lymphoma which was classified into 2 types based on histology. EATL is often, but not always, associated with celiac disease. EATL type I is a large cell lymphoma which is more common in frequency and highly associated with celiac disease compared with type II. Jejunum and ileum are the common sites, although EATL can rarely occur in the duodenum, stomach and colon or outside the gastrointestinal tract. We herein presented one case of gastric EATL, which happened in a 73-year-old Chinese male patient. Histologically, the tumor was composed of polymorphic (pleomorphic, anaplastic, immunoblastic) lymphoid cells and numerous inflammatory cells, including histiocytes, neutrophils and eosnophils in the background. The pleomorphic lymphoid cells were diffuse and strongly positive for CD3 and partially positive for CD30, while negative for CD4, CD5, CD8 or CD56. The gastric EATL should be distinguished from other gastric lesions, such as peptic ulcer, poorly-differentiated adenocarcinoma and other types of lymphoma.

Pleomorphic lipoma lacking mature fat component in extensive myxoid stroma: a great diagnostic challenge

Pleomorphic lipoma is a relatively uncommon entity, and is considered as a variant of spindle cell lipoma. Histologically, spindle cell lipoma/pleomorphic lipoma consists of varying quantity of mature fat, bland spindle cells and ropey collagen. In addition, pleomorphic lipoma is characterized by multinucleate giant cells, which possess the “floret-like” nuclei and marked pleomorphism. So, in contrast to spindle cell lipoma, pleomorphic lipoma is more easily misdiagnosed as a malignant tumor. Herein, we report a peculiar case of pleomorphic lipoma occurring in axilla with entirely devoid of mature fat in a 71-year-old male. The histopathological findings demonstrated the tumor was made up of bland spindle cells admixed with scattered “floret-like” cells and irregular ropey collagen in an extensive myxoid stroma. Immunostaining showed that the tumor was positive for the Vimentin, Bcl-2 and CD34, and was negative for S-100, desmin, CD68, and α–SMA. Although no fat component was found in the whole section, the tumor was still diagnosed as a pelomprphic lipoma. To our knowledge, this is the third reported case of pelomprphic lipoma which entirely lacked lipomatous component. Because of the existence of atypical multinucleate giant cells and lack of mature fat, this tumor may be easily misdiagnosed nonlipomatous lesions, such as myxoid fibrosarcoma, giant cell fibroblastoma.

So, it is necessary to pay careful attention to the histological spectrum of pleomorphic lipoma, including the tumor with devoid of fat, and it should be kept in mind that pelomprphic lipoma still can be diagnosed even if lacking lipomatous component.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1967123180611361

The alveolar epithelial differentiation of glandular inner lining cells in a mucoepidermoid carcinoma of the lung: a case report

Mucoepidermoid carcinoma is a common malignant epithelial tumor of salivary glands, but relatively rare in lung. The histological features of mucoepidermoid carcinoma of the lung are similar to its counterpart arising from the salivary glands. Here, we reported a special tumor that occurred in the medial segment of the right lower lobe in a 22-year-old man. This tumor exhibited typical features of mucoepidermoid carcinoma with 3 cell types: squamoid cells, mucin-secreting cells and cells of intermediate type. These 3 types of cells organized into cysts, nests, glands and solid patterns. Specially, the inner lining cells of some glandular structures were uniform cuboidal and hobnail-like, similar to the alveolar epithelial cells. Immunohistochemistry staining revealed that the inner lining cells of glandular structures were positive for thyroid transcription factor-1 and surfactant protein-B, used as markers of alveolar epithelial cells, and were negative for p63. These findings for the first time demonstrated a rare alveolar epithelial differentiation of glandular inner lining cells in a mucoepidermoid carcinoma of the lung.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7095988968057804.

Inflammatory angiomyolipoma of the liver: a rare hepatic tumor

Angiomyolipoma (AML) is a rare mesenchymal neoplasm of the tumor, composed of a varying heterogeneous mixture of three tissue components: blood vessels, smooth muscle and adipose cells. Hepatic AML may demonstrate a marked histological diversity. We herein present one case of hepatic AML exhibiting prominent inflammatory cells in the background, which happened in a 61-year-old Chinese female patient, without signs of tuberous sclerosis. Histologically, the striking feature was the infiltration of numerous inflammatory cells in the background, including small lymphocytes, plasma cells, and eosnophils. The tumor cells were spindled and histiocytoid in shape, with slightly eosinophilic cytoplasm, and arranged along the vessels or scattered among the inflammatory background. Sinusoid structure was obviously seen in the tumor. Mature adipocytes and thick-walled blood vessels were focally observed at the boundaries between the tumor and surrounding liver tissues. The tumor cells were positive immunostaining for HMB-45, Melan-A, and smooth muscle actin. The inflammatory AML should be distinguished from other tumors with inflammatory background such as inflammatory myofibroblastic tumor and follicular dendritic cell tumor and deserves wider recognition for its occurrence as a primary hepatic tumor.

The co-expression of cytokeratin and p63 in epithelioid angiosarcoma of the parotid gland: a diagnostic pitfall

Summary

Epithelioid angiosarcoma of the parotid gland is rare, and may pose a great diagnostic challenge. We report a case of primary epithelioid angiosarcoma in a 64-year-old male without history of radiation. The histopathological findings demonstrated a high grade epithelioid neoplasm. Immunostaining showed that the tumor was positive for the pan-cytokeratin, p63, cytokeratin18, Vimentin and vascular markers CD31, and was negative for CD34, cytokeratin5/6, cytokeratin7, cytokeratin20, CD68, CD30, S-100, HMB45, desmin, α–SMA and CD45. The tumor was diagnosed as an epithelioid angiosarcoma. To our knowledge, this is the first reported case of angiosarcoma which showed common positivity for cytokeratin and p63. In addition to cytokeratin, p63 is considered a useful marker for carcinoma. The co-expression of cytokeratin and p63 in epithelioid angiosarcoma represents a diagnostic pitfall. Thus, using a panel of antibodies is essential for distinguishing this tumor from poorly differentiated carcinoma.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6548916707504750

Expression and significance of stem cell markers in pulmonary sclerosing haemangioma

AIMS

The two major types of cells of pulmonary sclerosing haemangioma (PSH) with the same origin show significant differences in morphological phenotype. Whether these differences are caused by their different differentiation status is still uncertain. The aim of this study was to analyse their differentiation status by detecting the expression of several stem cell markers in PSH.

METHODS AND RESULTS

The expression of stem cell markers was examined by using streptavidin peroxidase (SP) immunohistochemisty in 45 PSH specimens. Also, the two types of cells were, respectively, captured by laser capture microdissection (LCM) from 28 PSH specimens, and total RNA was then extracted followed by reverse transcription-polymerase chain reaction (RT-PCR). The results demonstrated that the expression rates of ABCG2, Notch1 and Notch3 in polygonal cells were significantly higher than those in cuboidal cells (P < 0.05), and the expression levels of ABCG2, Notch3 and Jagged1 in polygonal cells were clearly higher than those in cuboidal cells (P < 0.05).

CONCLUSION

The data obtained provided evidence that the two types of cells in PSH may be different in differentiation status. The differentiation difference between the two types of cells might lead to variation in their morphological phenotype.

In pulmonary sclerosing hemangioma expression of β-catenin, Axin, and C-myc differs between the two cell types

Previous studies have shown that pulmonary sclerosing hemangioma is a tumor derived from primitive respiratory epithelium, but its character and the differentiation status of the two cell types (polygonal and cuboidal) composing the lesion are still controversial. We hypothesize that the polygonal cells are immature compared with cuboidal cells and have higher proliferative activity. To further study this question, we examined the expression of β-catenin, Axin, and C-myc by immunostaining in 45 primary sclerosing hemangioma (PSH) specimens. The two cell types were captured by laser capture microdissection from 28 PSH specimens, and total RNA was extracted. Messenger RNA (mRNA) expression of Axin and C-myc was examined by reverse transcription polymerase chain reaction (RT-PCR). By immunostaining, β-catenin was predominantly strongly expressed on the cell membrane of cuboidal cells, while in polygonal cells, β-catenin was predominantly expressed in the cytoplasm and significantly decreased on cell membranes. Axin was expressed in cuboidal cells in 93 % of our 45 cases, but only expressed in 18 % of these in polygonal cells. C-myc expression in polygonal cells was significantly stronger than in cuboidal cells (P < 0.05). RT-PCR showed that the expression level of Axin mRNA in cuboidal cells was significantly higher than in polygonal cells (P < 0.05), and expression level of C-myc mRNA in polygonal cells was significantly higher than in cuboidal cells (P < 0.05).The two PHS cell types have distinct expression of β-catenin, Axin, and C-myc, suggesting that their differentiation status may be different. The higher expression of C-myc in polygonal cells suggests that these cells might have higher proliferative activity.

Facilitation of phosphorus adsorption onto sediment by aquatic plant debris

Aquatic plant debris in lakes or rivers may affect phosphorus flux in water-sediment systems. In this study, either aquatic plant debris or typical plant components (cellulose or glucose), were added into a system of sediment (50 g) and overlying water (2L) with different initial SRP (soluble reactive phosphorus) concentrations to investigate the impact. After 18 days of treatment with 4 g of plant debris, the SRP in the overlying water for 0.5 and 2 mg L(-1) initial SRP tests at 30°C decreased by 41 and 53%, respectively, compared to the treatments without plant debris. Cellulose and glucose treatments gave similar results as plant debris treatment. When the water-sediment system was sterilized, the cellulose- or glucose-facilitated decrease in SRP vanished. Additionally, in the non-sterilized system, the glucose treatment significantly increased both the microbial biomass carbon and the microbial biomass phosphorous in the sediment. Although total phosphorous in the sediment increased with glucose treatment, its water soluble and iron associated inorganic fractions, two labile phosphorus fractions, were clearly reduced. Our results suggest that the short-term retention of plant debris in water systems facilitates a decrease in overlying water SRP through microbe-mediated mechanisms of phosphorus adsorption and stabilization in sediment.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Transpositional activation of mPing in an asymmetric nuclear somatic cell hybrid of rice and Zizania latifolia was accompanied by massive element loss

We have reported previously that the most active miniature inverted terminal repeat transposable element (MITE) of rice, mPing, was transpositionally mobilized in several rice recombinant inbred lines (RILs) derived from an introgressive hybridization between rice and wild rice (Zizania latifolia Griseb.). To further study the phenomenon of hybridization-induced mPing activity, we undertook the present study to investigate the element's behavior in a highly asymmetric somatic nuclear hybrid (SH6) of rice and Z. latifolia, which is similar in genomic composition to that of the RILs, though probably contains more introgressed alien chromatins from the donor species than the RILs. We found that mPing, together with its transposase-donor, Pong, underwent rampant transpositional activation in the somatic hybrid (SH6). Because possible effects of protoplast isolation and cell culture can be ruled out, we attribute the transpositional activation of mPing and Pong in SH6 to the process of asymmetric somatic hybridization, namely, one-step introgression of multiple chromatin segments of the donor species Z. latifolia into the recipient rice genome. A salient feature of mPing transposition in the somatic hybrid is that the element's activation was accompanied by massive loss of its original copies, i.e., abortive transpositions, which was not observed in previously reported cases of mPing activity. These data not only corroborated our earlier finding that wide hybridization and introgression may trigger transpositional activation of otherwise quiescent transposable elements, but also suggest that transpositional mobilization of a MITE like mPing can be accompanied by dramatic reduction of its original copy numbers under certain conditions, thus provide novel insights into the dynamics of MITEs in the course of genome evolution.

Abnormal expression of p120-catenin, E-cadherin, and small GTPases is significantly associated with malignant phenotype of human lung cancer

Studies on a variety of cell lines have shown that p120-catenin can directly regulate the stability of E-cadherin complexes and control the activity of small GTPases to influence cell adhesion. Despite this data, clinical studies of human solid tumors have not been reported to investigate these protein interactions. To explore the correlation between p120-catenin, E-cadherin, and small GTPases in human lung cancer, we examined the expression patterns of p120-catenin, E-cadherin, RhoA, Cdc42, and Rac1, and their prognostic significance in 138 patients with non-small cell lung cancer (NSCLC). While normal bronchial epithelium showed strong membrane expression of p120-catenin and E-cadherin, lung cancer tissues had reduced membrane expression and ectopic cytoplasmic expression of p120-catenin and E-cadherin. Expression of RhoA, Cdc42, and Rac1 was also found to be higher in tumor tissue than in normal lung tissue. A correlation between abnormal p120-catenin, E-cadherin expression, and overexpression of specific small GTPases was also associated with poor differentiation, high TNM stage, and lymph node metastasis in NSCLC patients. We also used an in vitro model to evaluate their expression, and to determine whether protein expression correlated with the invasive capacity of lung cancer cell lines. Consistent with our in vivo data, abnormal expression of p120-catenin and E-cadherin with overexpression of specific small GTPases were significantly associated with the high metastatic capacity of BE1 cells. Based on our results, we conclude that abnormal p120-catenin expression correlates with abnormal E-cadherin expression and specific small GTPase overexpression, which contribute to the malignancy-related to NSCLC.

Endosperm-specific hypomethylation, and meiotic inheritance and variation of DNA methylation level and pattern in sorghum (Sorghum bicolor L.) inter-strain hybrids

Understanding dynamics and inheritance of DNA methylation represents important facets for elucidating epigenetic paradigms in plant development and evolution. Using four sets of sorghum (Sorghum bicolor L.) inter-strain hybrids and their inbred parents, the developmental stability and inheritance of cytosine methylation in two tissues, leaf and endosperm, by MSAP analysis were investigated. It was found that in all lines (inbred and hybrid) studied, endosperm exhibited a markedly reduced level of full methylation of the external cytosine or both cytosines at the CCGG sites relative to leaf, which caused a variable reduction in the estimated total methylation level in endosperm by 6.89-19.69% (11.47% on average). For both tissues, a great majority of cytosine methylation profiles transmitted to F1 hybrids, however, from 1.69 to 3.22% of the profiles showed altered patterns in hybrids. Both inherited and altered methylation profiles can be divided into distinct groups, and their frequencies are variable among the cross-combinations, and between the two tissues. The variations in methylation level and pattern detected in the hybrids were not caused by parental heterozygosity, and they could be either non-random or stochastic among hybrid individuals. Homology analysis of isolated bands that showed endosperm-specific hypomethylation or variation in hybrids indicated that diverse sequences were involved, including known-function cellular genes and mobile elements. RT-PCR analysis of six genes representing endosperm-specific hypomethylation in MSAP profiles indicated that all showed higher expression in endosperm than in leaf, suggesting involvement of methylation state in regulating tissue-specific or tissue-biased expression in sorghum. Analysis on leaf-RNA from 5-azacytidine-treated plants further corroborated this possibility.

Endosperm-specific hypomethylation, and meiotic inheritance and variation of DNA methylation level and pattern in sorghum (Sorghum bicolor L.) inter-strain hybrids

Understanding dynamics and inheritance of DNA methylation represents important facets for elucidating epigenetic paradigms in plant development and evolution. Using four sets of sorghum (Sorghum bicolor L.) inter-strain hybrids and their inbred parents, the developmental stability and inheritance of cytosine methylation in two tissues, leaf and endosperm, by MSAP analysis were investigated. It was found that in all lines (inbred and hybrid) studied, endosperm exhibited a markedly reduced level of full methylation of the external cytosine or both cytosines at the CCGG sites relative to leaf, which caused a variable reduction in the estimated total methylation level in endosperm by 6.89-19.69% (11.47% on average). For both tissues, a great majority of cytosine methylation profiles transmitted to F1 hybrids, however, from 1.69 to 3.22% of the profiles showed altered patterns in hybrids. Both inherited and altered methylation profiles can be divided into distinct groups, and their frequencies are variable among the cross-combinations, and between the two tissues. The variations in methylation level and pattern detected in the hybrids were not caused by parental heterozygosity, and they could be either non-random or stochastic among hybrid individuals. Homology analysis of isolated bands that showed endosperm-specific hypomethylation or variation in hybrids indicated that diverse sequences were involved, including known-function cellular genes and mobile elements. RT-PCR analysis of six genes representing endosperm-specific hypomethylation in MSAP profiles indicated that all showed higher expression in endosperm than in leaf, suggesting involvement of methylation state in regulating tissue-specific or tissue-biased expression in sorghum. Analysis on leaf-RNA from 5-azacytidine-treated plants further corroborated this possibility.

Extent and pattern of DNA methylation alteration in rice lines derived from introgressive hybridization of rice and Zizania latifolia Griseb

We have reported previously that introgression by Zizania latifolia resulted in extensive DNA methylation changes in the recipient rice genome, as detected by a set of pre-selected DNA segments. In this study, using the methylation-sensitive amplified polymorphism (MSAP) method, we globally assessed the extent and pattern of cytosine methylation alterations in three typical introgression lines relative to their rice parent at approximately 2,700 unbiased genomic loci each representing a recognition site cleaved by one or both of the isoschizomers, HpaII/MspI. Based on differential digestion by the isoschizomers, it is estimated that 15.9% of CCGG sites are either fully methylated at the internal Cs and/or hemi-methylated at the external Cs in the rice parental cultivar Matsumae. In comparison, a statistically significant increase in the overall level of both methylation types was detected in all three studied introgression lines (19.2, 18.6, 19.6%, respectively). Based on comparisons of MSAP profiles between the isoschizomers within the rice parent and between parent and the introgression lines, four major groups of MSAP banding patterns are recognized, which can be further divided into various subgroups as a result of inheritance of, or variation in, parental methylation patterns. The altered methylation patterns include hyper- and hypomethylation changes, as well as inter-conversion of hemi- to full-methylation, or vice versa, at the relevant CCGG site(s). Most alterations revealed by MSAP in low-copy loci can be validated by DNA gel blot analysis. The changed methylation patterns are uniform among randomly selected individuals for a given introgression line within or among selfed generations. Sequencing on 31 isolated fragments that showed different changing patterns in the introgression line(s) allowed their mapping onto variable regions on one or more of the 12 rice chromosomes. These segments include protein-coding genes, transposon/retrotransposons and sequences with no homology. Possible causes for the introgression-induced methylation changes and their implications for genome evolution and crop breeding are discussed.

Seroepidemiology of hepatitis C virus in Beijing, China

To investigate the seroprevalence of hepatitis C virus (HCV) in China we tested sera from healthy individuals without hepatitis and no history of parenteral blood exposure and from patients admitted to a hepatitis hospital in Beijing. Sera were tested for anti-HCV by first-generation enzyme immunoassay; selected positives were tested with two second-generation EIAs, one utilizing recombinant antigens and the other synthetic peptides. We found anti-HCV with the following frequencies: 10 of 164 (6%) individuals with no disease; 2 of 36 (5.5%) patients with acute non-A non-B hepatitis (NANBH); 26 of 39 (67%) patients with post-transfusion NANBH; 10 of 34 (29%) patients with chronic hepatitis negative for hepatitis B surface antigen (HBsAg); 3 of 30 (10%) patients with chronic HBsAg-positive hepatitis; 0 of 19 patients with acute HBsAg-positive hepatitis. Of 24 repeat-positive sera, 19 were positive by both and 4 by one second-generation tests. We conclude that hepatitis C infection is common in China, that it contributes substantially to the incidence of post-transfusion hepatitis, and that HCV plays a significant role in both acute and chronic hepatitis. Further studies are needed to extend these observations and to define the predominant routes of transmission of HCV in China.

Critical role for cathepsin B in mediating caspase-1-dependent interleukin-18 maturation and caspase-1-independent necrosis triggered by the microbial toxin nigericin

The potassium ionophore nigericin induces cell death and promotes the maturation and release of IL-1beta in lipopolysaccharide (LPS)-primed monocytes and macrophages, the latter depending on caspase-1 activation by an unknown mechanism. Here, we investigate the pathway that triggers cell death and activates caspase-1. We show that without LPS priming, nigericin alone triggered caspase-1 activation and IL-18 generation in THP-1 monocytic cells. Simultaneously, nigericin induced caspase-1-independent necrotic cell death, which was blocked by the cathepsin B inhibitor CA-074-Me and other cathepsin inhibitors. Cathepsin B activation after nigericin treatment was determined biochemically and corroborated by rapid lysosomal leakage and translocation of cathepsin B to the cytoplasm. IL-18 maturation was prevented by both caspase-1 and cathepsin B inhibitors in THP-1 cells, primary mouse macrophages and human blood monocytes. Moreover, IL-18 generation was reduced in THP-1 cells stably transformed either with cystatin A (an endogenous cathepsin inhibitor) or antisense cathepsin B cDNA. Collectively, our study establishes a critical role for cathepsin B in nigericin-induced caspase-1-dependent IL-18 maturation and caspase-1-independent necrosis.

The IBD1 locus for susceptibility to Crohn's disease has a greater impact in Ashkenazi Jews with early onset disease

OBJECTIVE

Recent studies have suggested that a susceptibility gene located on chromosome 16 and designated IBD1 may contribute to the development of Crohn's disease (CD). However, these findings were observed in predominantly non-Jewish populations; in the three studies where Ashkenazi Jews were included for analysis, the results have been widely divergent. Because Ashkenazi Jews are known to have a higher incidence of the disease than non-Jews, we sought to determine whether this previously reported linkage could be extended to the Ashkenazi population. In addition, we examined whether Ashkenazi Jewish patients with an early age of onset (< or = 21 yr) showed greater evidence of linkage to this locus.

METHODS

Linkage analysis for the IBD1 region was performed on 123 Ashkenazi Jewish CD patients distributed among 53 families. Only patients with four Jewish grandparents were considered to be Jewish. Of the 123 Ashkenazi Jewish patients, 75 (61%) had an age of onset < or = 21 yr.

RESULTS

Ashkenazi Jews showed only modest evidence of linkage (nonparametric linkage 1.63, p = 0.05) to the IBD1 locus. However, when the Ashkenazi population was subdivided on the basis of age of onset, there was a striking increase in linkage in families where affected individuals had an age of onset < or = 21 yr (nonparametric linkage 3.02, p = 0.002). In contrast, there was no evidence of linkage in the Jewish families where all affected individuals had an age of onset > 21 yr.

CONCLUSIONS

The IBD1 gene plays a greater role in conferring susceptibility to CD in Jews with early onset disease than in Jews with late onset disease.

Expression analysis of the human caspase-1 subfamily reveals specific regulation of the CASP5 gene by lipopolysaccharide and interferon-gamma

Based on high sequence homology, there are six members in the caspase-1 subfamily: caspases 1, 4, 5, and 13 in humans and caspases 1, 11, and 12 in mice. Only caspase-1 is known to activate interleukin-1beta and interleukin-18, and caspase-11 activates pro-caspase-1 in vivo. Almost nothing is known about caspases 4, 5, and 13. Here we report a sensitive and specific polymerase chain reaction system to analyze closely related genes. We employed this system to analyze the gene expression and regulation of human caspases 1, 4, 5, and 13, demonstrating that they have different expression patterns in normal tissues and cell lines. Interferon-gamma strongly induced CASP1 and CASP5 but not CASP4 or CASP13 gene expression in HT-29 colon carcinoma cells. In contrast to the mRNA, interferon-gamma up-regulated caspase-1 but not caspase-5 protein. In the monocytic cell line THP-1, CASP1 mRNA and caspase-1 protein are expressed constitutively, and their levels were not increased by lipopolysaccharide, whereas both CASP5 mRNA and caspase-5 protein were induced by lipopolysaccharide. Caspase-1 subfamily members displayed different in vitro activities toward pro-caspases 1 and 3 and pro-interleukin-1beta. Our results demonstrate that caspase-1 and caspase-5 levels are modulated by interferon-gamma and lipopolysaccharide, respectively, and suggest that caspase-1 subfamily members are differentially regulated and may have distinct functions.

HLA class II alleles associated with susceptibility and resistance to Crohn's disease in the Jewish population

Previous studies have suggested that susceptibility to Crohn's disease (CD) is associated with the histocompatibility complex (HLA) class II alleles DR1, DQ5, and DR13 in the Caucasian population, DR7 in the French and German populations, and DR4 and DQ4 in the Japanese population. However, little is known about the relationship between HLA class II alleles and CD in the Jewish population since these previous studies included few Jewish individuals. In order to determine whether the HLA associations observed with predominantly non-Jewish populations were also present in the Jewish CD population and whether there were any HLA class II alleles uniquely associated with CD in the Jewish population, 132 CD patients, of which 82 were Ashkenazi Jewish, were HLA-typed using serologic and DNA methods. Ethnically matched controls were similarly typed. No association with DR1 or DR13 was observed in the Jewish CD population although an association with DR13 (OR [odds ratio] = 5.3, p = 0.02) was observed in the non-Jewish CD population. However, an association with DR15 (OR = 2.7, p = 0.03), which is normally associated with ulcerative colitis, was observed in the Jewish, but not non-Jewish, CD group. In addition, a strong negative association was observed with DR3, which was especially striking in the Jewish population (OR = 0.35, p = 0.025); similar negative associations with DR3 have been observed by others using non-Jewish populations. Furthermore, a significant negative association with DR7 (OR = 0.45, p = 0.04) was observed in the Jewish, but not non-Jewish, population. Consistent with this was the negative association with DQ2 (OR = 0.38, p = 0.005), which is in strong linkage disequilibrium with both DR3 and DR7, in the Jewish, but not non-Jewish, population. These studies support previous suggestions that susceptibility to CD in Jewish and non-Jewish populations is determined by distinct genes and provide further support to the hypothesis that a gene on the DR3 haplotype may protect against CD. Furthermore, protection is conferred by the same or another gene found on Jewish, but not non-Jewish, DR7 haplotypes.

Dimethylamiloride-induced differentiation of HL-60 cells

AIM

To study the effect of 5-(N,N-dimethyl) amiloride (DMA) on the proliferation and differentiation of HL-60 cells in vitro.

METHODS

MTT assay to test cytotoxicity; cell staining and NBT reduction to test cell differentiation.

RESULTS

DMA inhibited HL-60 cells growth in a concentration-dependent manner, and IC50 value for 96 h was 31.7 (95% confidence limits: 6.3-57.1) mumol.L-1. DMA also induced granulocytic differentiation in HL-60 cells. The percentage of differentiating cells increased from 6.5% to 70% after DMA 100 mumol.L-1 treatment for 3 d. The differentiating effect of DMA was distinguishable from amiloride, 5-(N-ethyl-N-isopropyl)amiloride (EIPA), and (5-(N-ethyl-N-isopropyl)amiloride (MIA). None among the amiloride, EIPA, and MIA were capable of triggering the differentiation of HL-60 cells.

CONCLUSION

DMA inhibited the proliferation of HL-60 cells and induced differentiation of HL-60 cells.

Anticipation in Crohn's disease may be influenced by gender and ethnicity of the transmitting parent

OBJECTIVE

We sought to examine whether anticipation (an earlier age of onset in succeeding generations) is observed in Crohn's disease (CD) patients within the New York metropolitan area, and whether there are differences in the degree of anticipation with respect to gender and ethnicity of the affected parent.

METHODS

Sixty-one parent-child pairs both affected by CD were identified; about half of the pairs were of Ashkenazi Jewish descent. An additional 17 pairs of second-degree relatives with CD were also identified. The intergenerational difference in age at diagnosis (AAD) was used to perform regression analysis and the degree of anticipation among subsets of patients separated on the basis of gender and ethnicity of the transmitting parent was determined.

RESULTS

The AAD was consistently (90% of the time) lower in the younger member of the 61 parent-child pairs (35.3+/-1.6 yr vs 20.8+/-1.1 yr, p = 0.0001). Furthermore, the degree of anticipation was significantly greater for father-child pairs (20.6+/-3.2 yr) than for mother-child pairs (11.7+/-2.1 yr). However, when the patient population where the parent had an AAD of < 28 was analyzed separately, there was a lack of clear-cut evidence of anticipation in the population as a whole. Only when the population was subdivided by ethnicity was there convincing evidence of anticipation in the Jewish population.

CONCLUSION

Ascertainment bias may be responsible for the apparent anticipation observed in the CD population as a whole or in the nonJewish CD subgroup. However, the Jewish CD population displays strong evidence of anticipation even after correction for ascertainment bias.

The induction of acute phase proteins by lipopolysaccharide uses a novel pathway that is CD14-independent

LPS (endotoxin) and proinflammatory cytokines (IL-6, IL-1, and TNF-alpha) are potent inducers of acute phase proteins (APP). Since LPS induces high levels of these cytokines after its interaction with CD14, a protein expressed on the surface of monocytes and neutrophils, it has been assumed that CD14 mediates the LPS induction of APP expression. To test this hypothesis, CD14-deficient and control mice were injected with low doses of LPS, and the expression of several APP that are normally up-regulated by LPS was measured. CD14-deficient mice showed no alteration in the induction of APP, including serum amyloid A, LPS-binding protein, fibrinogen, or ceruloplasmin; in contrast, C3H/HeJ mice, which carry a mutation in the Lps gene, do not up-regulate the expression of these proteins. These studies show that the up-regulation of APP by LPS utilizes a non-CD14 receptor and requires a functional Lps gene.

Differences in risk of Crohn's disease in offspring of mothers and fathers with inflammatory bowel disease

OBJECTIVE

To determine whether there are any unusual patterns of transmission of susceptibility to inflammatory bowel disease (IBD) within multiplex families.

METHODS

Individuals with IBD were recruited for genome-wide screening of susceptibility genes. The extent of familial aggregation and blood relationships in multiplex families were determined by questionnaires given to participants followed up by confirmation of disease diagnosis by participants' physicians.

RESULTS

Of 135 families identified in which both a parent and a child had IBD, 93 involved transmission of susceptibility to disease from mother to child versus 42 examples of transmission from father to child (p = 0.00001, exact two-tailed binomial test). This distortion in transmission on the basis of the sex of the parent was observed only among non-Jewish pairs with Crohn's disease (CD), in which, of 33 parent-child pairs with CD, disease susceptibility was transmitted from the mother 28 times (p = 0.00007).

CONCLUSION

Susceptibility to CD in a subset of patients may involve a gene that is imprinted.

Evidence that the receptor for soluble CD14:LPS complexes may not be the putative signal-transducing molecule associated with membrane-bound CD14

Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule.

Novel polypeptide toxins with crab lethality from the sea anemone Anemonia erythraea

The sea anemone Anemonia erythraea was found to contain polypeptide toxins with crab lethality as well as hemolysins. Three polypeptide toxins (AETX I, II and III) were isolated by gel filtration on Sephadex G-50 and reverse-phase HPLC on TSKgel ODS-120T. A geographic variation in toxin composition was suggested. The LD50 against crabs of AETX I, II and III were estimated to be 2.2, 0.53 and 0.28 microg/kg, respectively, but none of the toxins showed lethality in mice. The amino acid sequences of the three toxins were deduced from sequencings of the whole molecules and their enzymatic fragments. Amino acid analyses and molecular mass determinations supported the accuracy of the deduced sequences. AETX I, comprising 47 amino acid residues including 6 half-Cys residues, is an analog of sea anemone type I toxins. On the other hand, AETX II and III, which are highly homologous with each other, are quite distinct from the known sea anemone polypeptide toxins in that they are composed of 59 residues including 10 half-Cys residues. Interestingly, both toxins have sequence similarities with neurotoxins isolated from the Brazilian 'armed' spider Phoneutria nigriventer.

Effect of interstimulus interval on pairing-induced LTP of Aplysia sensorimotor synapses in cell culture

Long-term potentiation of Aplysia sensorimotor synapses (apLTP) can be induced in Hebbian fashion by pairing brief tetanic stimulation of the sensory neuron with depolarization of the motor neuron. It has been proposed that Hebbian apLTP plays a significant role in classical conditioning of the defensive withdrawal reflex of Aplysia. However, as originally demonstrated, Hebbian apLTP is induced by simultaneous pairing of sensory neuron stimulation and motor neuron depolarization, whereas in the Aplysia classical conditioning paradigm the onset of the conditioned stimulus (CS) precedes the onset of the unconditioned stimulus (US) by 0.5 s. Therefore, if Hebbian apLTP does indeed mediate classical conditioning in Aplysia, temporally offset delivery of presynaptic stimulation and postsynaptic depolarization must be able to support apLTP. To ascertain whether temporally offset pre- and postsynaptic stimuli can support apLTP, we varied the interstimulus interval (ISI) between the onset of presynaptic tetanus and the onset of postsynaptic depolarization. In the first set of experiments we determined the amount of potentiation that results from varying the temporal interval between the onset of a single presynaptic tetanus and the onset of a single bout of postsynaptic depolarization. The ISI between the onset of the two stimuli ranged from 0.0 to 5.0 s. Significant apLTP was obtained with ISIs of 0.0 and 0.5 s. but the amount of potentiation was independent of the order in which the presynaptic and postsynaptic stimuli were delivered. Because classical conditioning of the withdrawal reflex in Aplysia is dependent on the temporal order of the CS and US, in a second set of experiments we compared the efficacy of forward and backward pairing of pre- and postsynaptic stimulation with the use of a conditioning-like protocol. Forward pairing and backward pairing (0.5-s ISI) yielded equal amounts of apLTP. These data raise questions for the hypothesis that Hebbian apLTP mediates classical conditioning of the withdrawal reflex in Aplysia. Our results indicate that Hebbian apLTP alone cannot fully account for classical conditioning in Aplysia. An additional cellular mechanism is required to explain the temporal specificity present in the behavioral results.

Specific cleavage of the retinoblastoma protein by an ICE-like protease in apoptosis

Interleukin 1beta-converting enzyme-like (ICE-like) proteases are important mediators of apoptosis in diverse cell types and organisms. However, the role of these proteases in apoptosis cannot be satisfactorily explained on the basis of the physiological functions of their known substrates. Here we show that the C-terminal 42 amino acid peptide of the retinoblastoma (Rb) protein, an important cell cycle regulator with a known anti-apoptotic function, is specifically cleaved off by an ICE-like protease in tumour necrosis factor (TNF)- and staurosporine-induced apoptosis. Cleavage of Rb induced by TNF was blocked in vivo and in vitro by two specific inhibitors of ICE-like proteases, and in vitro by a point mutation (Asp886 to Ala) within the ICE-like protease cleavage site of Rb, (883)DEAD(886). An antibody raised against the C-terminal 15 amino acid peptide of Rb recognized the full-length but not the cleaved form of Rb. The extent of Rb cleavage correlated directly with TNF-induced apoptosis in all tumour cell lines examined. Cleaved Rb bound cyclin D3 and inhibited the transcriptional activity of E2F-1, but failed to bind to the regulatory protein MDM2, which has been implicated in apoptosis. As Rb suppresses cell death and its C-terminus has important regulatory functions, our results suggest that Rb cleavage is an important event in apoptosis.

Cyclin D3 sensitizes tumor cells to tumor necrosis factor-induced, c-Myc-dependent apoptosis

c-Myc is an important mediator of apoptosis in cytokine- or serum-deprived cells and sensitizes various cell types to tumor necrosis factor alpha (TNF) cytotoxicity. However, downstream mediators of c-Myc-dependent apoptosis are largely unknown. In this study, we investigated whether one or more cyclins which, like c-Myc, are important regulators of the cell cycle are involved in TNF-induced apoptosis downstream of c-Myc. Cyclin D3 and c-Myc levels in HeLa and fibrosarcoma cells correlated with sensitivity of these cells to TNF-induced apoptosis, as both proteins were highly expressed in TNF-sensitive HeLa D98 cells and HT-1080 fibrosarcoma cells but not in their TNF-resistant counterparts, HeLa H21 and SS-HT-1080 cells, respectively. All other cyclins tested were equally expressed in all tumor cell lines. Reduction in the expression of c-Myc by dexamethasone or inhibition of the transcriptional activity of c-Myc by introduction of a dominant negative form of c-Myc into TNF-sensitive HeLa D98 cells strongly suppressed the expression of cyclin D3 (but none of the other cyclins) and rendered the cells resistant to TNF-induced apoptosis. Conversely, introduction of the c-myc gene into TNF-resistant, c-Myc- and cyclin D3-deficient HeLa H21 cells resulted in enhanced cyclin D3 expression and TNF killing. When cyclin D3 expression in HeLa cells was altered by sense or antisense cyclin D3 cDNA, there was a concomitant alteration in their susceptibility to TNF-induced apoptosis without any change in c-Myc levels. Overall, our results show that cyclin D3 sensitizes tumor cells to TNF-induced apoptosis and indicate that the expression of c-Myc and expression of cyclin D3 in HeLa and in HT-1080 fibrosarcoma cells are closely linked.

Long-term depression of Aplysia sensorimotor synapses in cell culture: inductive role of a rise in postsynaptic calcium

1. Activation of sensory neurons at 2 Hz for 15 min induces long-term depression (LTD) of isolated Aplysia sensorimotor synapses in cell culture. 2. Prior infusion of the Ca2+ chelator 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA) into the postsynaptic motor neuron blocks the induction of LTD, but not short-term synaptic depression. 3. Invertebrate central synapses possess the capacity for LTD. This form of long-term synaptic plasticity may play an important role in learning in Aplysia.

Two separate functions are encoded by the carboxyl-terminal domains of the yeast cyclase-associated protein and its mammalian homologs. Dimerization and actin binding

The yeast adenylyl cyclase-associated protein, CAP, was identified as a component of the RAS-activated cyclase complex. CAP consists of two functional domains separated by a proline-rich region. One domain, which localizes to the amino terminus, mediates RAS signaling through adenylyl cyclase, while a domain at the carboxyl terminus is involved in the regulation of cell growth and morphogenesis. Recently, the carboxyl terminus of yeast CAP was shown to sequester actin, but whether this function has been conserved, and is the sole function of this domain, is unclear. Here, we demonstrate that the carboxyl-terminal domains of CAP and CAP homologs have two separate functions. We show that carboxyl-terminals of both yeast CAP and a mammalian CAP homolog, MCH1, bind to actin. We also show that this domain contains a signal for dimerization, allowing both CAP and MCH1 to form homodimers and heterodimers. The properties of actin binding and dimerization are mediated by separate regions on the carboxyl terminus; the last 27 amino acids of CAP being critical for actin binding. Finally, we present evidence that links a segment of the proline-rich region of CAP to its localization in yeast. Together, these results suggest that all three domains of CAP proteins are functional.

A polypeptide toxin in the sea anemone Actinia equina homologous with other sea anemone sodium channel toxins: isolation and amino acid sequence

The sea anemone (Actinia equina) was newly established to contain a polypeptide toxin (named Ae I) having lethal activity to crabs, besides the well-known cytolytic toxins (equinatoxins) of proteinic nature. Ae I, with a minimum lethal dose against crabs of 25 micrograms/kg, was easily isolated by gel filtration on Sephadex G-50 and reverse-phase HPLC on Nucleosil 300-7C18. Its amino acid composition is characterized by the abundance of Gly, the absence of Ala and the presence of Met. The complete amino acid sequence of Ae I was determined. Ae I has high sequence homology with type 1 sea anemone neurotoxins. Interestingly, the polypeptide chain of Ae I comprises 54 amino acid residues, being 5-8 residues longer than the known type 1 toxins having 46-49 residues.

CD14-independent responses to LPS require a serum factor that is absent from neonates

Monocytes/macrophages and neutrophils can respond to endotoxin via a high-affinity receptor (CD14), requiring low levels of LPS (&lt; 1 ng/ml) as well as through another pathway(s) that requires high levels of LPS (&gt; 10 ng/ml). Both pathways result in the secretion of high levels of cytokines, such as TNF-alpha, and the up-regulation of various other effector molecules. To further define the activation of cells by LPS via a pathway that does not involve CD14, we have used an experimental model that distinguishes CD14-dependent from CD14-independent responses using saturating amounts of an anti-CD14 Ab to block the CD14-dependent response. Analysis of the ability of various individuals to respond to LPS via via both the CD14-dependent and CD14-independent pathways shows that adults can respond via both pathways; furthermore, in the presence of 100 ng of LPS/ml, the primary response is CD14 independent. In contrast to the response by adults, neonates can only respond via the CD14-dependent pathway. Further analysis has shown that the CD14-independent pathway requires a non-CD14 plasma protein present in adult plasma that is either missing or nonfunctional in neonate (cord) plasma.

CD14-independent responses to LPS require a serum factor that is absent from neonates

Monocytes/macrophages and neutrophils can respond to endotoxin via a high-affinity receptor (CD14), requiring low levels of LPS (< 1 ng/ml) as well as through another pathway(s) that requires high levels of LPS (> 10 ng/ml). Both pathways result in the secretion of high levels of cytokines, such as TNF-alpha, and the up-regulation of various other effector molecules. To further define the activation of cells by LPS via a pathway that does not involve CD14, we have used an experimental model that distinguishes CD14-dependent from CD14-independent responses using saturating amounts of an anti-CD14 Ab to block the CD14-dependent response. Analysis of the ability of various individuals to respond to LPS via via both the CD14-dependent and CD14-independent pathways shows that adults can respond via both pathways; furthermore, in the presence of 100 ng of LPS/ml, the primary response is CD14 independent. In contrast to the response by adults, neonates can only respond via the CD14-dependent pathway. Further analysis has shown that the CD14-independent pathway requires a non-CD14 plasma protein present in adult plasma that is either missing or nonfunctional in neonate (cord) plasma.

Recombinant soluble CD14 prevents mortality in mice treated with endotoxin (lipopolysaccharide)

Endotoxic shock is a life-threatening condition mediated by cytokines released after exposure to bacterial LPS/endotoxin. Activation of monocytes and neutrophils by the binding of LPS to the membrane receptor, CD14, plays a key role in this response. Furthermore, a soluble form of the CD14 receptor enhances the endothelial cell response to LPS. We show here that despite the agonist effects of soluble CD14 on the endothelial cell response to LPS, recombinant soluble CD14 is able to protect mice from LPS-induced lethality. This protection appears to be associated with the inhibition of TNF-alpha release. These results suggest that the soluble CD14 receptor may represent a new form of therapy for endotoxic shock in humans.

Recombinant soluble CD14 prevents mortality in mice treated with endotoxin (lipopolysaccharide)

Endotoxic shock is a life-threatening condition mediated by cytokines released after exposure to bacterial LPS/endotoxin. Activation of monocytes and neutrophils by the binding of LPS to the membrane receptor, CD14, plays a key role in this response. Furthermore, a soluble form of the CD14 receptor enhances the endothelial cell response to LPS. We show here that despite the agonist effects of soluble CD14 on the endothelial cell response to LPS, recombinant soluble CD14 is able to protect mice from LPS-induced lethality. This protection appears to be associated with the inhibition of TNF-alpha release. These results suggest that the soluble CD14 receptor may represent a new form of therapy for endotoxic shock in humans.

Hebbian induction of long-term potentiation of Aplysia sensorimotor synapses: partial requirement for activation of an NMDA-related receptor

Long-term potentiation (LTP) of Aplysia sensorimotor synapses in cell culture can be induced by pairing sensory neuron activity with depolarization of the motorneuron. This pairing-induced LTP is prevented by perfusion with D,L-2-amino-5-phosphononovalerate (APV), a selective antagonist for the N-methyl-D-asparate (NMDA) subclass of glutamate receptors. Repeated pairing of presynaptic activity with postsynaptic depolarization induces LTP comprising both APV-sensitive and APV-insensitive components. Infusing BAPTA, a selective Ca2+ chelator, into the postsynaptic motoneuron completely blocks pairing-induced LTP. These results demonstrate that Aplysia sensorimotor synapses are capable of hebbian LTP-similar to that exhibited by synapses in the mammalian hippocampus - and suggest a role for this type of synaptic plasticity in classical conditioning of the defensive withdrawal reflex of Aplysia.

Long-term potentiation of Aplysia sensorimotor synapses in cell culture: regulation by postsynaptic voltage

Long-term potentiation (LTP) has been proposed as a cellular mechanism for associative learning in vertebrates. Induction of one type of LTP--observed at synapses in the CA1 region of the mammalian hippocampus--is regulated by the voltage of the postsynaptic cell. To date, a similar form of LTP has not been demonstrated for any invertebrate synapse. We now report that high-frequency stimulation can induce LTP of sensorimotor synapses of the marine mollusc Aplysia in cell culture. Moreover, induction of this form of LTP appears to involve a voltage-dependent postsynaptic mechanism because pairing tetanic stimulation of the presynaptic cell with strong hyperpolarization of the postsynaptic cell blocks the induction of LTP.