The pernicious cycle of VLUs in Brazil: epidemiology, pathogeny and auxiliary healing methods.

Venous leg ulcers (VLUs) represent the most advanced stage of chronic venous insufficiency. Despite the large body of knowledge available regarding the risk factors and aetiopathogeny of the condition, patients referred to public health care systems in developing countries often do not receive adequate diagnosis or early treatment, leading to clinical evolution and disease recurrence. This review collates updated information about the epidemiology, risk factors, aetiopathogeny, diagnosis, ulcer healing methods and determinant factors of the pernicious cycle of VLUs in developing countries, with a focus on the Brazilian setting.

Immunohistochemical localization of Notch signaling molecules in ameloblastomas.

We examined Notch signaling molecules, Notch1 and Jagged1, in serial large cases of typical solid/multicystic ameloblastoma. In general, Notch positive staining products were frequently detected in the cytoplasms of the cells. In the same cells, Jagged positive staining were also frequently observed, while only occasionally positive in peripheral cells, especially in cuboidal cells. The results showed that these morphogenesis regulation factors are closely related to cytological differentiation in neoplastic cells of ameloblastoma. The Notch and Jagged positive-cell ratios were frequently positive, and the ratios were nearly the same between the varied histopathological, cytological patterns. However, the less-differentiated cells were fewer in number than that of well-differentiated cells.

Total endovascular debranching of the aortic arch.

BACKGROUND: Significant morbidity and mortality are related to conventional aortic replacement surgery. Endovascular debranching techniques, fenestrated or branched endografts are time consuming and costly. OBJECTIVE: We alternatively propose to use endovascular approach with parallel grafts for debranching of aortic arch. METHODS: Under general anesthesia, 12 F sheaths were inserted in the femoral, axillary and common carotid arteries for vascular accesses. ViaBahn grafts 10 - 15 cm in length were placed into the aortic arch from right common carotid, left common carotid and left axillary arteries, until the tip of each graft reached into the ascending aorta. Through one femoral artery, the aortic stent -graft was positioned and delivered. Soon after, the parallel grafts were sequentially delivered. Self-spanding Wallstents(R) were used for parallel grafts reinforcement. Ballooning was routinely used for parallel grafts and rarely for aortic graft. RESULTS: This technique was used in 2 cases. The first one was a lady with 72 years old, with an aortic retrograde dissection from left subclavian artery and involving remaining arch branches. Through right common carotid artery a stent-graft was placed in the ascending aorta and through the left common carotid artery a ViaBahn was inserted parallel to the former. A thoracic endograft then covered all the aortic arch dissection extending into the ascending aorta close to the sinu -tubular junction. The second case was a 82 year old male patient with a 7 cm aortic arch aneurysm. Through both common carotid arteries ViaBahn grafts were introduced and positioned into the ascending aorta. Soon after, the deployment of the thoracic stent graft covered all parallel grafts of the aortic arch, excluding the aneurysm. Both cases did not have neurologic or cardiac complications and were discharged 10 days after the procedure. CONCLUSIONS: This technique may be a good minimal invasive off-the-shelf technical option for aortic arch ''debranching''. More data and further improvements are required before this promising technique can be widely advocated.

Choosing to make an effort: the role of striatum in signaling physical effort of a chosen action.

The possibility that we will have to invest effort influences our future choice behavior. Indeed deciding whether an action is actually worth taking is a key element in the expression of human apathy or inertia. There is a well developed literature on brain activity related to the anticipation of effort, but how effort affects actual choice is less well understood. Furthermore, prior work is largely restricted to mental as opposed to physical effort or has confounded temporal with effortful costs. Here we investigated choice behavior and brain activity, using functional magnetic resonance imaging, in a study where healthy participants are required to make decisions between effortful gripping, where the factors of force (high and low) and reward (high and low) were varied, and a choice of merely holding a grip device for minimal monetary reward. Behaviorally, we show that force level influences the likelihood of choosing an effortful grip. We observed greater activity in the putamen when participants opt to grip an option with low effort compared with when they opt to grip an option with high effort. The results suggest that, over and above a nonspecific role in movement anticipation and salience, the putamen plays a crucial role in computations for choice that involves effort costs.

Prevalence of deep vein thrombosis and pulmonary embolism in superficial thrombophlebitis of the lower limbs: prospective study of 60 cases.

AIM: Superficial thrombophlebitis (ST) ascending the lower limbs is a common disease, which may be associated with deep vein thrombosis (DVT) and pulmonary embolism (PE). The aim of this study was to investigate the prevalence of DVT and PE as complications of ascending ST of the lower limbs in the great saphenous vein (GSV) or SSV (SSV) and probable risk factors. METHODS: For this study 60 consecutive patients were enrolled with ascending ST of the GSV or SSV, seen between 2000 and 2003 at a public hospital in Botucatu, SP, Brazil. All patients were assessed clinically, by venous Duplex scanning of the lower limbs to confirm ST and test for DVT, and by means of pulmonary scintigraphy to test for PE. RESULTS: In 13 ST cases (21.67%) there was concomitant DVT and 17 ST patients (28.33%) also had PE. Eleven patients had a clinical status suggestive of DVT, but only in eight of these (61.5%), this clinical diagnosis was confirmed. Fourteen patients had a clinical status suggestive of PE, and this diagnosis was confirmed in six cases (35.30%). ST patients who also had DVT and/or PE were given anticoagulant treatment with heparin and warfarin. None of the variables studied was predictive of DVT or PE (P>0.05). However, the presence of varicose veins reduced the risk of patients having DVT (relative risk=9.09; 95%CI:1.75 - 50.00 and P=0.023). CONCLUSIONS: The prevalence rates of PE (28.3%) and DVT (21.6%) were elevated in this sample of ascending ST cases, indicating a need for detailed assessment of patients for signs of these complications, including for therapeutic management decision making.

Trimetazidine and N-acetylcysteine in attenuating hind-limb ischemia and reperfusion injuries: experimental study in rats.

AIM: Lower-limb traumatic injury associated with ischemia and followed by reperfusion (I/R) is a common severe situation in muscle lesions due to trauma and hypoxia followed by local and systemic injuries induced by oxygen-derived free radical release during reperfusion. The aim of this study was to evaluate the attenuating effects of trimetazidine (TMZ) and N-acetylcysteine (NAC) in such situation. METHODS: The muscles at the root of the right hind limb of Wistar rats were cross-sectioned, preserving femoral vessels and nerves and clamping the femoral artery for four hours. The clamp was then released and the femoral artery has been reperfused for 2 hours. Rats were randomly divided in groups of ten as follows: Group 1: sham I/R, treated with saline; Group 2: I/R, treated with saline; Group 3: sham I/R, treated with TMZ (7.5 mg/kg/dose); Group 4: sham I/R, treated with NAC (375 mg/kg/dose); Group 5: I/R treated with TMZ (7.5 mg/kg/dose); Group 6: I/R treated with NAC (375 mg/kg/dose). All rats received two intravenous bolus injections of the drugs, one before ischemia and one before reperfusion. Oxidative stress in plasma (MDA, total, oxidized and reduced glutathione), creatinephosphokinase (CPK), optical and electron microscopy and pelvic extremity circumference and volume were studied. RESULTS: No statistical differences were found between the groups for MDA or total and reduced glutathione. Oxidized glutathione increased significantly in groups 5 and 2. Limb circumference as well as limb volume increased in all groups over time, mainly in groups 5, 2 and 1. CPK increased in all groups, being highest in groups 5, 6 and 2. Histological lesions were present in all but sham groups, being less severe in group 6. Soleus muscle analyses at electron microscopy exhibit some degree of alteration in all groups. CONCLUSIONS: This experimental model simulated severe limb trauma associated with ischemia and reperfusion, and, as such, it was aggressive, causing severe injury and local inflammatory reaction. The model did not show antioxidant action from NAC, and possible antioxidant action from TMZ was insufficient to attenuate tissue injuries.

Examination of in vivo gelatinolytic activity in rheumatoid arthritis synovial tissue using newly developed in situ zymography and image analyzer.

OBJECTIVE: The aim of this study was to examine in vivo gelatinolytic activity of rheumatoid arthritis (RA) synovium using a newly developed in situ zymography (ISZ) method and pathological image analyzer, and to evaluate the relationship between this activity and several features on RA. METHODS: A total of 8 samples of synovium were obtained from RA patients during surgery, and 8 samples from osteoarthritis (OA) patients were examined as controls. Furthermore, total 14 samples of syovium were obtained for comparison among radiographical classifications as Larsen grade (4 cases of grade III, 5 cases of grade IV and 5 cases of grade V). These specimens were frozen with OCT compound immediately after surgery. Frozen sections were applied to a newly developed gelatin-coated FIZ film (Fuji Film Co.Tokyo.Japan) designed for use ISZ, and incubated at 37 degrees C for 6 hours. Using an image analyzer (image processor for analytical pathology; IPAP), two variables were measured as indicators of in vivo gelatynolytic activity: optical density of gelatinolyzed area (ODG), and ratio of gelatinolyzed area (RGA). Also, we investigated the relationship between these indicators and the following variables: radiographic changes (Larsen grades), clinical data (C-reactive protein concentration), histological score of synovial tissue (modified Rooney's score), and expression of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 (assessed by immunohistochemistry). RESULTS: RA synovium had significantly higher RGA and lower ODG than OA, indicating higher gelatinolytic activity in RA. Synovium from cases with Larsen grade IV or V had significantly lower ODG than cases with grade III, but there was no significant difference in RGA between grades. There was no significant correlation between gelatinolytic activity (ODG or RGA) and either CRP or modified Rooney's Histological Score. The results of ISZ indicate that the gelatinolyzed areas were mainly localized in the lining area, with a small amount scattered throughout the stroma. The results of immunohistochemistry indicate that MMP-2, MMP-9, TIMP-1 and TIMP-2 were expressed in areas of gelatinolysis. CONCLUSIONS: The present results indicate that in vivo gelatinolytic activity of synovium is stronger in RA than in OA. They also indicate that gelatinolytic activity of RA synovial cells is stronger in cases with Larsen grade IV or V than in cases with grade III, although the gelatinolyzed area is similar. Gelatinolytic activity, as indicated by optical density and the gelatinolyzed area, differed between regions, even within the same specimen, suggesting an imbalance between production of proteinases and their inhibitors. We believe that the present zymography method can contribute to the elucidation of biological enzymatic activity of RA synovium.

Effects of pentoxifylline and n-acetylcysteine on injuries caused by ischemia and reperfusion of splanchnic organs in rats.

AIM: Occlusion and reperfusion of splanchnic arteries cause local and systemic changes due to the release of cytotoxic substances and the interaction between neutrophils and endothelial cells. This study evaluated the role of pentoxifylline (PTX) and n-acetylcysteine (NAC) in the reduction of ischemia, reperfusion shock and associated intestinal injury. METHODS: Sixty rats were divided into 6 groups of 10 animals. Rats in three groups underwent mesenteric ischemia for 30 minutes followed by 120 minutes of reperfusion, and were treated with saline (SAL-5 mL/kg/h), pentoxifylline (PTX-50 mg/kg) or n-acetylcysteine (NAC-430 mg/kg/h). The other 3 groups underwent sham ischemia and reperfusion (I/R) and received the same treatments. Hemodynamic, biochemical and histological parameters were evaluated. RESULTS: No significant hemodynamic or intestinal histological changes were seen in any sham group. No histological changes were found in the lung or liver of animals in the different groups. There was a progressive decrease in mean arterial blood pressure, from mean of 111.53 mmHg (30 minutes of ischemia) to 44.30+/-19.91 mmHg in SAL-I/R, 34.52+/-17.22 mmHg in PTX-I/R and 33.81+/-8.39 mmHg in NAC-I/R (P<0.05). In all I/R groups, there was a progressive decrease in: aortic blood flow, from median baseline of 19.00 mL/min to 2.50+/-5.25 mL/min in SAL-I/R; 2.95+/-6.40 mL/min in PTX-I/R and 3.35+/-3.40 mL/min in NAC-I/R (P<0.05); in the heart rate, from mean baseline of 311.74 bpm to 233.33+/-83.88 bpm in SAL-I/R, 243.20+/-73.25 bpm in PTX-I/R and 244.92+/-76.05 bpm in NAC-I/R (P<0.05); and esophageal temperature, from mean baseline of 33.68 degrees C to 30.53+/-2.05 degrees C in SAL-I/R, 30.69+/-2.21 degrees C in PTX-I/R and 31.43+/-1.03 degrees C in NAC-I/R (P<0.05). In the other hand, there was an attenuation of mucosal damage in the small intestine of the animals receiving PTX, and only in the ileum of the animals receiving NAC. No changes were found in ileum or plasma malondialdehyde levels in any group. CONCLUSIONS: PTX was more efficient in reducing histological lesions than NAC, but neither treatment prevented hemodynamic changes during splanchnic organs I/R.

Incorrect use of thromboprophylaxis for venous thromboembolism in medical and surgical patients: results of a multicentric, observational and cross-sectional study in Brazil.

OBJECTIVES: Although effective strategies for the prevention of venous thromboembolism (VTE) are widely available, a significant number of patients still develop VTE because appropriate thromboprophylaxis is not correctly prescribed. We conducted this study to estimate the risk profile for VTE and the employment of adequate thromboprophylaxis procedures in patients admitted to hospitals in the state of São Paulo, Brazil. METHODS: Four hospitals were included in this study. Data on risk factors for VTE and prescription of pharmacological and non-pharmacological thromboprophylaxis were collected from 1454 randomly chosen patients (589 surgical and 865 clinical). Case report forms were filled according to medical and nursing records. Physicians were unaware of the survey. Three risk assessment models were used: American College of Chest Physicians (ACCP) Guidelines, Caprini score, and the International Union of Angiololy Consensus Statement (IUAS). The ACCP score classifies VTE risk in surgical patients and the others classify VTE risk in surgical and clinical patients. Contingency tables were built presenting the joined distribution of the risk score and the prescription of any pharmacological and non-pharmacological thromboprophylaxis (yes or no). RESULTS: According to the Caprini score, 29% of the patients with the highest risk for VTE were not prescribed any thromboprophylaxis. Considering the patients under moderate, high or highest risk who should be receiving prophylaxis, 37% and 29% were not prescribed thromboprophylaxis according to ACCP (surgical patients) and IUAS risk scores, respectively. In contrast, 27% and 42% of the patients at low risk of VTE, according to Caprini and IUAS scores, respectively, had thromboprophylaxis prescribed. CONCLUSION: Despite the existence of several guidelines, this study demonstrates that adequate thromboprophylaxis is not correctly prescribed: high-risk patients are under-treated and low-risk patients are over-treated. This condition must be changed to insure that patients receive adequate treatment for the prevention of thromboembolism.

Long-term histopathologic evaluation of inferior vena cava after modified Greenfield filter implantation. Experimental study in sheep.

AIM: The authors assess a modified Greenfield filter (GF) for the long-term patency, filter tilting and histopathologic alterations of the inferior vena cava (IVC). METHODS: Adult sheep (n=7) underwent modified GF placement in the IVC. Cavograms were obtained every 3 months and pulmonary angiography at 12 months. Histopathologic and scanning electron microscopy (SEM) analyses were performed on the IVC explanted at 12 months. RESULTS: Cavograms showed that all IVC were patent at the end of the study. Filter tilting occurred in 2/7 animals and extrusion of struts was not observed. Macroscopic examination at explantation showed minimal venous wall thickening. Microscopic examination showed minimal IVC fibrosis and intimal hyperplasia. SEM showed endothelium on the IVC surface at the filter implantation site and a presumed endothelial layer covering partially or totally the struts. The interface filter-IVC was covered by deposits of leucocytes and platelets. No signs of pulmonary embolism were found in all pulmonary angiograms of both groups. CONCLUSION: The modified filter presented good biocompatibility, stability and absence of thrombogenicity at 12 months. It presented low tendency to tilting and extrusion of struts. The long-term histopathologic alterations in vena caval wall were minimal and the appearance of the studied filters in the IVC was similar to stents placed in the arterial system.

Extrinsic compression of popliteal artery in asymptomatic athlete and non-athlete individuals. A comparative study using duplex scan (color duplex sonography).

AIM: Extrinsic compression of the popliteal artery and absence of surrounding anatomical abnormalities characterize the functional popliteal artery entrapment syndrome (PAES). The diagnosis is confirmed to individuals who have typical symptoms of popliteal entrapment and occlusion or important stenosis of the popliteal artery with color duplex sonography (CDS), magnetic resonance imaging (MRI) or arteriography during active plantar flexion-extension maneuvers. However, variable result findings in normal asymptomatic subjects have raised doubts as to the validity of these tests. The purpose of this study was to compare the frequency of popliteal artery compression in 2 groups of asymptomatic subjects, athletes and non-athletes. METHODS: Forty-two individuals were studied. Twenty-one subjects were indoor soccer players, and 21 were sedentary individuals. Physical activity was evaluated through questionnaires, anthropometric measurements, and cardiopulmonary exercise test. Evaluation of popliteal artery compression was performed in lower limbs with CDS, ankle-brachial index (ABI) measurements and continuous wave Doppler of the posterior tibial artery. RESULTS: The athletes studied fulfilled the criteria of high level of physical activity whereas sedentary subjects met the criteria of low level of activity. Popliteal artery compression was observed with CDS in 6 (14.2%) studied subjects; 2 of whom (4.7%) were athletes and 4 (9.5%) were non-athletes. This difference was not statistically significant (p=0.21). Doppler of the tibial arteries and ABI measurements gave good specificity and sensibility in the identification of popliteal artery compression. CONCLUSIONS: The frequency of popliteal artery compression during maneuvers in normal subjects was 14.2% irrespective of whether or not they performed regular physical activities. Both Doppler and ABI showed good agreement with CDS and should be considered in screening popliteal arteries in individuals suspected of PAES.

Value of ultrasonographic contrast in duplex scanning of leg arteries. Comparison with conventional duplex scanning and arteriography.

AIM: Duplex scanning has been used in the evaluation of the aorta and proximal arteries of the lower extremities, but has limitations in evaluating the arteries of the leg. The utilization of ultrasonographic contrast (USC) may be helpful in improving the quality of the image in these arteries. The objective of the present study was to verify whether the USC increases the diagnostic accuracy of patency of the leg arteries and if it diminishes the time needed to perform duplex scanning. METHODS: Twenty patients with critical ischemia (20 lower extremities) were examined by standard duplex scanning, duplex scanning with contrast and digital subtraction arteriography (DSA). The 3 arteries of the leg were divided into 3 segments, for a total of 9 segments per limb. Each segment was evaluated for patency in order to compare the 3 diagnostic methods. Comparison was made between standard duplex scanning and duplex scanning with contrast in terms of quality of the color-coded Doppler signal and of the spectral curve, and also of the time to perform the exams. RESULTS: Duplex scanning with contrast was similar to arteriography in relation to patency diagnosis (p>0.3) and even superior in some of the segments. Standard duplex scanning was inferior to arteriography and to duplex scanning with contrast (p<0.001). There were improvements of 70% in intensity of the color-coded Doppler signal and 76% in the spectral curve after the utilization of contrast. The time necessary to perform the examinations was 23.7 minutes for standard duplex scanning and 16.9 minutes for duplex scanning with contrast (p<0.001). CONCLUSIONS: The use of ultrasonographic contrast increased the accuracy of the diagnosis of patency of leg arteries and diminished the time necessary for the execution of duplex scanning.

Healing process in anastomosis of homologous venous grafts preserved in glutaraldehyde implanted aorta of rabbits.

AIM: Autologous vein (AV) is sometimes not suitable or present for a vascular restoration. Homologous vein preserved in glutaraldehyde may be an alternative to AV, but little is yet known about this graft and its healing process after implantation in arteries. The purpose of this study was to compare the initial healing process of glutaraldehyde-tanned homologous venous grafts (group 1) with fresh autologous venous grafts (group 2), at 4 or 15 days. METHODS: Forty Norfolk rabbits were allocated in 2 groups of 20 animals each. The grafts was interposed in the infrarenal aorta of the rabbit. Anastomotic tensile strength (TS), hydroxyproline (HP) determination, and histology (HA) were performed. RESULTS: TS increased in both groups, from the 4th to 15th day, (p<0.01) in both proximal (G1: from 364.5+/-98.3 g to 491.8+/-107.3 g; G2: from 366.26+/-85.15 g to 518.46+/-82.79 g) and distal anastomosis (G1: from 363.53+/-96.26 g to 507.32+/-91.01 g; G2: from 352.30+/-102.41 g to 528.67+/-48.58 g), with no difference between the groups. HP did not change (p>0.10) in this same period and was similar in both groups, in the proximal (G1: from 677.99+/-153.98 microg/100 mg to 914.92+/-459.83 microg/100 mg; G2: from 668.65+/-170.28 microg/100 mg to 669.46+/-319.80 ug/100 mg) as well as in the distal anastomosis (G1: from 740.07+/-213.53 microg/100 mg to 923.52+/-270.57 microg/100 mg; G2: from 737.66+/-266.76 microg/100 mg to 707.68+/-171.25 microg/100 mg). Initial inflammatory and reparative features of the anastomosis were similar in both groups. CONCLUSION: We can conclude that the healing process of the glutaraldehyde-tanned homologous vein graft was similar to that of the fresh autologous venous graft.

Effect of diclofenac sodium on the healing process of end-to-end anastomosis in carotid arteries of rabbits. Histopathological and biomechanical studies.

AIM: Diclofenac sodium is a non-steroidal anti-inflammatory drug commonly used to attenuate painful inflammatory reactions in surgery. However, it may delay healing in the skin and gastrointestinal tract. The aim of this study was to evaluate the influence of Diclofenac in vascular healing. METHODS: Ninety rabbits had their carotid arteries sectioned and reconstructed by end-to-end anastomosis with interrupted sutures. The animals were randomly allocated into 3 groups of 30 each and treated by intramuscular route with saline (control), 5 mg/kg/day of diclofenac sodium (DS-5), and 10 mg/kg/day of diclofenac sodium (DS-10). Treatment began on the day of surgery and lasted 4 days. Angiography, biomechanical properties (failure load, failure elongation, yield point, yield point elongation, and stiffness were obtained from the load/elongation curve), macroscopic and histological examinations (hematoxylin-eosin, Masson, Calleja, Picrossirius-red), and scanning electron microscopy were studied in both arteries on the 3rd and 15th postoperative days. RESULTS: No significant differences in biomechanical properties were observed either in the 3 groups or the experimental times. The carotid artery healing process was similar in the 3 groups. CONCLUSION: Diclofenac sodium did not cause alterations nor delayed carotid artery healing.

Development of large pseudocysts adjacent to the knee joint in rheumatoid arthritis. Assessment of radiological and histopathological approaches.

Abstract This study examined the pathogenesis of large pseudocysts adjacent to knee joints in rheumatoid arthritis (RA). The radiological and histopathological features of 17 large subarticular pseudocysts in 12 knee joints of 10 patients were analyzed. Nine of the 10 patients were classified as class 2 according to Steinbrocker's functional class. Eight large pseudocysts were located at the lateral femoral condyle, seven were at the proximal part of the tibia, one was at the medial femoral condyle, and one was at the patella. The large pseudocysts were divided into two groups according to whether they did or did not connect with the joint cavity. Serial radiographs revealed that all large pseudocysts in communication with the joint cavity had enlarged gradually over the past several months. They extended from the subarticular area toward the bone marrow. Histopathological findings confirmed that holes allowing communication were located at a transitional zone between the ligament and the hyaline cartilage, and that rheumatoid granulation tissue invaded the large pseudocyst through these holes. The results of this study indicate that large pseudocysts are formed by the extension of articular inflammation. Moreover, repeated extrinsic mechanical stress due to walking and the aggressive inflammatory nature of rheumatoid arthritis play important roles in the formation of large pseudocysts.

Nomofungin: a new microfilament disrupting agent.

A new alkaloid, nomofungin, has been isolated from the fermentation broth of an unidentified endophytic fungus obtained from the bark of Ficus microcarpa L. The structure of nomofungin was determined by application of spectroscopic methods. The absolute stereochemistry of nomofungin was assigned by using the exciton chirality method. Nomofungin disrupts microfilaments in cultured mammalian cells and is moderately cytotoxic with minimum inhibitory concentrations (MICs) of 2 and 4.5 microg/mL against LoVo and KB cells, respectively. The ring system of nomofungin is unprecedented.

Cytotoxic cyclic norterpene peroxides from a Red Sea sponge Diacarnus erythraenus.

Investigation of the lipophilic extract of the Red Sea sponge Diacarnus erythraenus revealed one new norsesterterpene cyclic peroxide, aikupikoxide A (1), three new norditerpene cyclic peroxides, aikupikoxide B-D (2-4), and the known norterpene peroxides muqubilin and nuapapuin A methyl ester. In addition, a new sesquiterpene, O-methyl guaianediol, was isolated. Their structures were determined by means of spectroscopic methods. The cytotoxic activities for the isolated compounds have been reported.

The structure of microcarpalide, a microfilament disrupting agent from an endophytic fungus.

[structure: see text]. A new alkyl-substituted nonenolide, microcarpalide 1, has been isolated from fermentation broths of an unidentified endophytic fungus. Microcarpalide is weakly cytotoxic to mammalian cells and acts as a microfilament disrupting agent. The structure of 1 was elucidated by application of spectroscopic methods. The absolute configuration was determined by the exciton chirality method.

Effects of paclitaxel on cultured synovial cells from patients with rheumatoid arthritis.

BACKGROUND: Proliferation of synovial cells is considered to play a key role in rheumatoid arthritis (RA). Using paclitaxel, a unique antineoplastic agent known to suppress collagen-induced arthritis, we conducted an in vitro study of cell kinetics on cultured synovial cells from patients with RA. METHODS: Alterations of the cell cycle of cultured fibroblast-like synovial cells (FLSs) from patients with RA were studied using flow cytometry and laser scanning cytometry. Apoptosis and accumulation of cyclin concerning effects of paclitaxel were detected. RESULTS: Paclitaxel induced arrest of the cell cycle at G2/M phase and apoptosis in FLSs. The late stage of apoptosis was determined by the positivity of terminal deoxynucleotidyl transferase assay. Morphological observation by combined usage of both annexin V and propidium iodide on FLSs on a slide glass showed early apoptotic changes in detail. FLSs arrested at G2/M phase showed marked accumulation of cyclin B1. The effects of paclitaxel decreased on FLSs, which diminished proliferative activity. CONCLUSIONS: These data indicate that paclitaxel induces cell arrest at G2/M phase followed by apoptosis in human FLSs, which have high proliferative activity, and possible therapeutic effects of paclitaxel on RA.

Total structure determination of apratoxin A, a potent novel cytotoxin from the marine cyanobacterium Lyngbya majuscula.

Apratoxin A (1), a potent cytotoxin with a novel skeleton, has been isolated from the marine cyanobacterium Lyngbya majuscula Harvey ex Gomont. This cyclodepsipeptide of mixed peptide-polyketide biogenesis bears a thiazoline ring flanked by polyketide portions, one of which possesses an unusual methylation pattern. Its gross structure has been elucidated by spectral analysis, including various 2D NMR techniques. The absolute configurations of the amino acid-derived units were determined by chiral HPLC analysis of hydrolysis products. The relative stereochemistry of the new dihydroxylated fatty acid unit, 3,7-dihydroxy-2,5,8,8-tetramethylnonanoic acid, was elucidated by successful application of the J-based configuration analysis originally developed for acyclic organic compounds using carbon-proton spin-coupling constants ((2,3)J(C,H)) and proton-proton spin-coupling constants ((3)J(H,H)); its absolute stereochemistry was established by Mosher analysis. The conformation of 1 in solution was mimicked by molecular modeling, employing a combination of distance geometry and restrained molecular dynamics. Apratoxin A (1) possesses IC(50) values for in vitro cytotoxicity against human tumor cell lines ranging from 0.36 to 0.52 nM; however, it was only marginally active in vivo against a colon tumor and ineffective against a mammary tumor.