Regenerative abilities of a nanofiber wound dressing based on polylactide.

INTRODUCTION: The development of an ideal dressing for wound healing remains an unresolved issue. Thanks to the development of electrospinning technology, polymers in the form of nanofibers have come to the forefront of research interest. A modern and very promising dressing material is a “nonwoven” based on nanofibers of the synthetic polymer polylactide (PLA). The aim of this work was to assess the regenerative abilities of PLA in a standardized wound in a porcine model and compare our results to the literature data. METHODS: We applied PLA-based nanofiber dressings to the standardized wounds created in the porcine model. On the third, tenth, seventeenth and twenty-fourth days after the formation of the defect, we changed the wound dressing while taking a tissue sample for histopathological examination. We continuously monitored serum levels of acute phase proteins. RESULTS: PLA stimulated an inflammatory response. From the third day, the thickness of the fibrin layer with granulocytes increased. It reached its maximum values on the tenth day (mean 340 μm); at the same time the level of serum amyloid A, as a marker of inflammation, culminated. The individual phases of healing intertwined. The highest thickness values of the granulation tissue with cellular connective tissue (diameter 8463 μm) were reached on the seventeenth day. On the twenty-fourth day, the defects were healed macroscopically with a mean reepithelialization layer of 9913 μm. CONCLUSION: PLA-based nanofiber dressing potentiates the inflammatory, proliferative and reepithelialization phases of healing. Its structure perfectly mimics the extracellular matrix and serves as a 3D network for the growth and interaction of cellular elements. In addition to biocompatibility, PLA has a unique ability of two-phase biodegradation. It is a promising material for industrial production of dressing materials. Most of the available studies were performed in vitro. In vivo comparative studies approximating the use of PLA to daily practice are still missing.

Expression of selected microRNAs in pancreatic ductal adenocarcinoma: is there a relation to tumor morphology, progression and patient's outcome?

Pancreatic ductal adenocarcinoma (PDAC) remains a disease with extremely poor prognosis and limited effective available treatment. Differential expression of miRNAs isolated from tumor tissue has been proposed as a marker for tumor diagnosis, progression, and prognosis. Nevertheless, the prognostic value of miRNAs expression in PDACs for patient outcome still remains unclear. Expression of 7 selected miRNAs, isolated from FFPE samples of 54 PDAC patients, was quantified using RT-qPCR. The relationship of miRNA expression levels with tumor histology, clinicopathological characteristics, patient overall survival (OS), and progress-free survival (PFS), was subsequently evaluated. Overexpression of miR-21, miR-155, and miR-210 was observed in PDACs (up to 72.62, 232.36, and 181.38-fold, respectively), in comparison with non-neoplastic tissues. On the other hand, miR-96 and miR-217 were significantly downregulated in PDACs (up to one hundred times). No differences were, however, noticed between cancer and normal tissues for the expression levels of miR-148a and miR-196a. On the other hand, expression levels of all 7 miRNAs failed to demonstrate a significant correlation with parameters of tumor progression, such as tumor stage, grade, nodal involvement, perineural, and vascular invasion. The positive correlation of miR-210 levels was, however, observed with patient age (ρ=0.35). Additionally, miR-148a and miR-217 expressions have shown a positive association with tubular tumor growth pattern (ρ=0.39; ρ=0.28). The negative correlation of miR-148a values was also demonstrated with dissociative growth pattern and nuclear atypia (ρ=-0.30; ρ=-0.27). Finally, no statistically significant correlation could be demonstrated with the expression levels of all 7 tested miRNAs and PDAC patient survival; neither for OS nor for PFS (p>0.05). Our data have confirmed abnormal miRNAs expression in PDACs in comparison with adjacent non-neoplastic tissue. On the other hand, no correlation was discovered between miRNA expression and parameters of tumor progression. We have found a significant association between histologic tumor growth patterns and miRNA expression, making this work the first study, which analyses this aspect of PDAC. Finally, in our group of patients, no relationship of miRNA levels and patient prognosis could be demonstrated. Therefore, further investigation is required to evaluate the predictive and prognostic potential of miRNAs in a clinical setting.

Valproic Acid Decreases the Nuclear Localization of MDT-28, the Nematode Orthologue of MED28.

Mediator is a multiprotein complex that connects regulation mediated by transcription factors with RNA polymerase II transcriptional machinery and integrates signals from the cell regulatory cascades with gene expression. One of the Mediator subunits, Mediator complex subunit 28 (MED28), has a dual nuclear and cytoplasmic localization and function. In the nucleus, MED28 functions as part of Mediator and in the cytoplasm, it interacts with cytoskeletal proteins and is part of the regulatory cascades including that of Grb2. MED28 thus has the potential to bring cytoplasmic regulatory interactions towards the centre of gene expression regulation. In this study, we identified MDT-28, the nematode orthologue of MED28, as a likely target of lysine acetylation using bioinformatic prediction of posttranslational modifications. Lysine acetylation was experimentally confirmed using anti-acetyl lysine antibody on immunoprecipitated GFP::MDT-28 expressed in synchronized C. elegans. Valproic acid (VPA), a known inhibitor of lysine deacetylases, enhanced the lysine acetylation of GFP::MDT-28. At the subcellular level, VPA decreased the nuclear localization of GFP::MDT-28 detected by fluorescencelifetime imaging microscopy (FLIM). This indicates that the nuclear pool of MDT-28 is regulated by a mechanism sensitive to VPA and provides an indirect support for a variable relative proportion of MED28 orthologues with other Mediator subunits.

[Synchronous colorectal carcinoma and non-Hodgkin lymphoma - two case reports]. / Synchronní kolorektální karcinom a nehodgkinský lymfom - popis dvou prípadu.

Colorectal carcinoma represents an important cause of morbidity and mortality in adults, and its incidence in the Czech Republic is one of the world´s highest. The basic therapeutic approach is surgery: surgical removal of the affected part of the bowel together with regional lymph nodes dissection. The lymph nodes are routinely examined by means of histopathology. In this paper, we present two patients whose histological examination of mesocolic lymph nodes revealed an infiltration by synchronous malignant B-non-Hodgkin-lymphoma. Mantle cell lymphoma was present in the first case, and small cell lymphoma CLL/SLL in the other. Relevant literature is reviewed. KEY WORDS: synchronous - malignancy - colorectal - lymphoma - lymph node.

Expression of class III beta-tubulin in colorectal carcinomas: an immunohistochemical study using TU-20 & TuJ-1 antibody.

BACKGROUND & OBJECTIVE: Expression of class III beta-tubulin represents newly discovered marker of resistance to taxol-based chemotherapy in a wide spectra of carcinomas. However, very little is known about its expression in colorectal carcinomas. This study was done to determine class III beta-tubulin expression in a large series of colonic carcinomas, covering tumours with different degree of differentiation in order to evaluate its prospective significance in resistance to taxol-based chemotherapeutics and to compare the immunostaining profile of two widely used monoclonal antibodies, TU-20 and TuJ-1 METHODS: Sixty patients with colorectal carcinoma were enrolled; all of them were treated surgically by the resection. Twenty tumours were histologically assessed as G1, 20 as G2 and 20 as G3. Routine immunohistochemical procedure using TU-20 and TuJ-1 mouse monoclonal antibodies was applied to all 60 specimen and slides were evaluated using an optical microscope. RESULTS: Expression of class III beta-tubulin was detected in 14 tumours (23.3%), while remaining tumours were negative. Relatively higher frequency of class III beta-tubulin expression was observed in G3 tumours (10 cases) in comparison with G1 (3 cases) and G2 (1 case), respectively. Seven tumours displayed positive immunostaining with both tested antibodies TU-20 and TuJ-1. Six tumours showed expression of class III beta- tubulin in more than 1 per cent of neoplastic cell population. In remaining 8 tumours only individual scattered neoplastic cells exhibited class III beta-tubulin expression either with TU-20, or with TuJ-1 antibody. INTERPRETATION & CONCLUSION: Higher frequency of immunoreactivity was observed in poorly differentiated tumours. However, more than 90 per cent of neoplastic cell population did not express class III beta-tubulin in almost all tumours. These negative cells of colonic cancer could represent the potential target for taxane-based chemotherapy in the future. Our results indicate that TU-20 and TuJ-1 antibodies exhibit very similar immunoreactivity in neoplastic tissue.

[Neuroendocrine tumours of the alimentary tract--history and at present]. / Neuroendokrinní nádory trávicího ústrojí--historie a soucasnost.

Histological classification of the neuroendocrine tumours ("carcinoids") of the alimentary tract, as well as the opinion on biological behaviour of these tumours, changed rapidly within the last decade. Advances in knowledge of cellular biology of the diffuse endocrine system and in clinical diagnostics and treatment of tumours lead to the creation of a new histological classification of neuroendocrine tumours. This classification, apart from essential histological picture and immunohistological characterisation of the markers of neuroendocrine differentiation, also includes definition of biological properties of tumours based on their site of origin, mitotic and proliferative activity of the tumour cells and clinicopathological correlation, including the size of the tumour and its progression. Exact classification of an individual tumour into a corresponding category is an essential condition to select adequate following diagnostic procedures and optimal therapeutic strategy.

[Merkel cell carcinoma--immunohistochemical study in a group of 11 patients]. / Karcinom z Merkelových bunek--imunohistologická studie v souboru 11 pacientu.

The aim of our work was to confirm an immunohistochemical profile of routine markers of epithelial and neuroendocrine differentiation in eleven cases of Merkel cell carcinoma, as well as to study the expression of two markers of early phases of neuronal differentiation, namely reelin and class III beta-tubulin, markers which have not yet been studied in Merkel cell carcinomas. In all the investigated tumours the characteristic "dot-like" pattern of cytokeratin 20 immunoexpression, as well as negative immunostaining for cytokeratin 7 and thyroid transcription factor 1 (TTF-1) were disclosed; all the tumours showed neuroendocrine differentiation, expressing either neuron specific enolase (NSE) or chromogranin A(CgA), or both. An interesting finding was observed when the anti-cytokeratin monoclonal antibody MNF 116 was used. The characteristic "dot-like" pattern was detected in high proportion of tumours, including two samples of local recurrence of one of the carcinomas, where neoplastic cells have lost the expression of cytokeratin 20. The majority (91%) of Merkel cell carcinomas included in our group showed positive immunodetection of class III beta-tubulin when TU-20 antibody was used, while TuJ-1 immunostaining was surprisingly negative in all the investigated tumours. Detection of reelin was negative in almost all the studied Merkel cell carcinomas except for cases, where neoplastic cells revealed weak focal immunostaining in a minor portion of neoplastic cells.

[Gastroesophageal reflux disease. Standards of the Czech Society of Gastroenterology--actualization 2009]. / Refluxní choroba jícnu. Standardy Ceské gastroenterologické spolecnosti--aktualizace 2009.

Presently, gastroesophageal reflux disease is defined as a disorder where reflux of the stomach content is bothersome and/or brings about complications. The state when macroscopically detectable erosions of mucosa are present is known as erosive reflux disease and the term non-erosive reflux disease is used for the condition with no macroscopic erosions. Reflux oesophagitis is a frequent sign of the disease. A condition, where reflux symptoms persist or new occur and oesophagitis healing fails to take place despite maximum treatment, is classified as refractory gastroesophageal reflux disease. The main symptoms of gastroesophageal reflux disease include heartburn and regurgitation. Gastroesophageal reflux disease may, less frequently, manifest itself with isolated non-oesophageal symptoms, e.g. recurring upper respiratory tract infections or bronchial asthma. Etiopathogenesis involves refluxate, motility disorders, altered anatomic proportions, protective mechanisms disorder and external factors. Diagnosis takes place on the basis of typical symptomatology and endoscopic examination. Complications include bleeding, ulceration, strictures and Barrett's oesophagus. Lifestyle and dietary measures are an important treatment approach as are pharmacological (antisecretion and prokinetic agents) as well as surgical management.

[Leiomyoma of the abdomen wall. Case report]. / Leiomyom piední steny birisní.

Authors present the case report of the patient indicated to plastic of abdomen wall for large hernia. Per operation, tumor was found without communication with abdomen cavity and organs. Histopathologically, leiomyoma of the abdomen wall was identified.

[Diagnostics of the retrocalcaneal bursitis: possibilities of the use of new anatomical data]. / Diagnostika retrokalkaneárních burzitíd: moznosti vyuzití nových anatomických poznatku.

The anatomy and histology of the normal retrocalcaneal bursa (RB) was studied on both embalmed and fresh cadaverous material. The bursa is a constant structure, its upper and posterior walls are completely covered with the unilayered synovial membrane. Its anterior wall represents the superior facet of the calcaneal tuberosity, the posterior one corresponds to the anterior surface of the insertional part of the Achilles tendon. The superior wall is formed by the adipose tissue of the inferior part of Kager's triangle, extending into the cavity of the bursa in a form of constant large and irregularly shaped synovial fold. The normal anatomical features as well as some pathological changes of the bursa and its neighbourhood were demonstrated on examples of some case reports, by use of the ultrasonography and magnetic resonance investigations. In healthy individuals the space of the bursa was not figured in the ultrasonographic investigations, but was well apparent in the MR images. The pathological changes of the bursa are detectable by using of both methods, but the MR images present substantially precise quality of depiction. The authors recommend the use of presented new anatomical data for the improvement in differential diagnostic of the wide spectrum of achillar enthesopathies.

Human papillomavirus infection and tumours of the anal canal: correlation of histology, PCR detection in paraffin sections and serology.

Human papillomavirus infection is an important etiological factor in squamous cell carcinoma of the anus (SCCA). Different histological variants of anal carcinomas displaying squamous differentiation, previously classified as separate tumours, were recently reclassified as SCCA by the WHO. In our recent study the presence of HPV was detected by PCR in biopsy specimens of 42 different anal tumours, including SCCA and its histological variants (n=22), adenocarcinomas (n=5), tubulovillous adenomas (n=5) and anal condylomas (n=10). HR HPV16 (high risk - HR) was detected in 18 of SCCA specimens (81.8%). All histological variants, i.e. tumours with basaloid, squamous and mixed histological patterns, were represented among the HPV-positive cancers. Four tumours (18.2%) were HPV negative. Low-risk (LR) HPV types were not detected within the SCCA group. HPV16 was identified in one adenocarcinoma, while four cases were HPV negative. Two adenomas showed presence of HPV16; one showed simultaneous positivity for HPV33. The remaining three tumours were HPV negative. Seven anal condylomas (70%) were LR HPV 6 and/or 11 positive, while three were HPV negative. The presence of HR HPV types was not observed in anal condylomas. Our results provide further evidence in support of the etiological role of HR HPV infection in the development of SCCA regardless of its histological appearance.

Expansion of human mesothelial progenitor cells in a longterm three-dimensional organotypic culture of Processus vaginalis peritonei.

A 3D culture system was used to investigate the behaviour of mesothelial cells present in the wall of human processus vaginalis peritonei. Small tissue fragments placed on collagen sponges were cultured for 7, 14 and 21 days in medium supplemented with 10% FBS, and analysed for the expression and distribution of cytokeratins (CKAE1-AE3, CK19), p63, Ki-67, vimentin, CD34, and HBME-1. Before culture, flat mesothelial cells displayed immunoreactivity for cytokeratins, vimentin and HBME-1, while p63 and CD34 were negative. Mesenchymal cells within the stroma were vimentin-positive and endothelial cells of small vessels displayed positive staining for CD34. Cytokeratins, p63 and HBME-1 were negative in all stromal cells. In cultured fragments, flat mesothelial cells positive for vimentin, cytokeratins and HBME-1 proliferated, lining the fragment surface and migrating into the sponge. Capillaries showed morphological alterations; however, their immunoreactivity was comparable with the stroma prior to culture. Cells that had migrated into the sponge and displayed characteristics of mesothelial progenitors, predominantly spindleshaped and stellate, showed heterogeneous expression of markers especially in late phases of cultivation. These cells were constantly positive for vimentin, a small fraction was cytokeratin-positive and a few displayed HBME-1 immunoreactivity. CD34 was found in cells forming small cavities into the matrix, resembling newly formed blood vessels. Cells that had migrated into the sponge could be isolated and expanded in coculture with feeder NIH.3T3 fibroblasts. This system is suitable for studying growth and behaviour of mesothelial cells within their natural environment, providing a good method for isolation and expansion of their progenitor cells.

Chromophobe renal cell carcinoma with microcystic and adenomatous arrangement and pigmentation--a diagnostic pitfall. Morphological, immunohistochemical, ultrastructural and molecular genetic report of 20 cases.

We present clinical, morphological, immunohistochemical, ultrastructural and molecular genetic features of 20 cases of a peculiar form of chromophobe renal cell carcinoma (CRCC) with morphology differing from that of conventional CRCC. Microscopically, the typical features of the tumors were microcystic arrangement and formation of adenomatous structures. Microcystic areas were composed of smaller eosinophilic and bigger pale cells having cytological appearance typical of conventional CRCC. Cytological features of the adenomatous structures were mostly different from those of conventional CRCC. They had a typical columnar arrangement with nuclei positioned at the base of the glandular structures and a small amount of a deeply eosinophilic cytoplasm often endowed with brush border facing the lumen of the glands. In addition, all the tumors showed a brown pigmentation. The pigmentation was located mostly extracellularly, where it formed pools of heavy deposits. Microscopic calcifications present in all cases formed psammoma bodies or else the calcifications were more extensive and amorphous in shape. Ultrastructurally, the cells showed features characteristic of CRCC: typical cytoplasmic vesicles were 100-700 nm in size and mitochondria had tubulovesicular, lamellar or circular cristae. Some tumor cells contained dark, variously sized electron-dense pigment granules. Neither melanosomes nor membrane-bound neurosecretory granules were seen. Using fluorescence in-situ hybridization probes for chromosomes 1, 2, 6, 10, 13, 17 and 21, the tumors revealed massive loss of tested chromosomes typical for conventional CRCC. Monosomy of chromosomes 1, 2, 6, 10, 13 and 21 was found in 100, 36, 91, 82, 82, 82 and 64% of cases, respectively. None of the cases showed mutation of exons 9, 11, 13 and 17 of the c-kit gene. The important feature of pigmented microcystic chromophobe renal cell carcinoma is a relatively benign biological behavior and the absence of distant metastases and sarcomatoid transformation.

Expression of CD44v6 correlates with cell proliferation and cellular atypia in urothelial carcinoma cell lines 5637 and HT1197.

CD44 comprises a family of membrane adhesion molecules encoded by a single gene and diversified by alternative splicing and extensive posttranslational modifications. Alterations of CD44 expression patterns are linked to tumour invasion and formation of metastases. However, CD44 expression and its relation to the biological properties of tumours vary depending on the tumour type and origin. In transitional cell carcinoma of the urinary bladder, low CD44 expression is linked to enhanced tumour aggressiveness. We studied CD44 expression in two urothelial cancer cell lines, HT1197 and 5637. CD44s and a v6 variable exon-containing splice variants were detected in both cell lines by reverse transcription-PCR and by commercially available monoclonal antibodies. In both cell lines, Western blot analysis detected immunoreactive proteins with approximate sizes 70-85 kD, 95-110 kD, and 120-140 kD with CD44v6 antibody and weak bands with size 70-98 kD with CD44s antibody. At the cellular level, the pattern of CD44 immunoreactivity correlated with a lower level of cell differentiation and a higher degree of cell proliferation. In HT1197 cells, the CD44v6 was detected predominantly in small proliferating cells and in large multinuclear atypical cells. CD44s and CD44v6 displayed low immunoreactivity in HT1197 cells with a higher degree of epithelial differentiation. The 5637 cells expressed CD44v6 strongly and CD44s weakly. We conclude that CD44v6 expression correlates with a higher proliferative activity and with a stem cell-like phenotype in both cell lines and with cellular atypia in HT1197 cells.

Tissue culture loading test with storage granules from animal models of neuronal ceroid-lipofuscinosis (Batten disease): testing their lysosomal degradability by normal and Batten cells.

Storage granules (SGs) from ovine and canine models of Batten disease were found to be easily phagocytosed by four cell types studied. The cell types tested were human fibroblasts and peripheral monocytes (control and from a late infantile Batten disease patient), rat C6 cell line, and neonatal cardiomyocytes. The phagocytosed SGs elicited an increase in acid phosphatase activity which was localized in the phagolysosome. After phagocytosis SGs were followed for various times ranging from 7 to 21 days and were found to be of unchanged density (phase contrast), autofluorescence, and ultrastructural appearance. These findings point to their undergradability, or very low degree of degradability, in phagolysosomes in both normal or Batten cultured cells. The Batten disease SGs are not toxic and did not cause any adverse affect on the host cells. Either the normal clearance rate from lysosomes is too slow to be measured by this technique or subunit c accumulation in lysosomes need not result from a primary lysosomal protease defect. Subunit c may aggregate, because of the lack of some normally preventive factor, resulting in a physical barrier to the degradation of this highly apolar molecule.

Irritation effects of residual products derived from p(HEMA) gels. II. Compounds extracted from hydrogels.

Samples of poly(2-hydroxyethyl methacrylate) p(HEMA) hydrogels were prepared using three different polymerization initiators. The gels were washed in water under standard conditions. The extracts were then examined for intradermal irritation in rats using a radioactive indicator (113mIn). The irritation effects were dependent on the concentrations of the irritating substances and also on the gel type. Solid discs made of the gels, washed to varying degrees of purity, were also implanted into rats. Tissue irritation, as well as some other biological responses, were followed in situ using the radioindicator and common histological techniques. The irritation effects were very mild (even with the unextracted gel material). A possible explanation for the events taking place at the site of implantation is presented.

Cold jet: a method to obtain pure Schwann cell cultures without the need for cytotoxic, apoptosis-inducing drug treatment.

This paper presents a new and gentle method to separate Schwann cells from fibroblasts obtained from foetal rat dorsal root ganglia (DRG). The method exploits the different growth and adhesion characteristics of fibroblasts and Schwann cells under different experimental conditions such that antiproliferative (cytotoxic) drugs or time-consuming centrifugation is not needed. Standard procedures were used to obtain mixed cultures of Schwann cells, fibroblasts and neurons. After about 5 days further purification of the cells was achieved by exploiting the different responses of Schwann cells and fibroblasts to a temperature shock. Cooling the cells with cold phosphate-buffered saline (PBS), followed by pipetting cold medium directly on top of the cells ('cold jet'), resulted in specific detachment of Schwann cells and neurons, whereas fibroblasts remained securely attached. Schwann cells attached to the surface of new, uncoated culture dishes whereas neurons did not. Two cycles of the cold jet procedure resulted in nearly pure (98-100%) cultures of Schwann cells. Besides being gentle, this method is easy and fast, and because cytotoxic drugs are not used, it does not affect cell survival negatively.

Cultivation of rat fetal spinal cord slices in a semi-solid medium: a new approach to studying axonal outgrowth and regeneration.

A soft agar culture system was used for the cultivation of spinal cord slices with the purpose of improving the evaluation of the dynamics of axonal outgrowth and development. Slices of the spinal cord of 15-day-old fetal Wistar rats were cultured in a 0.5% agar culture medium. The sprouting and outgrowth of axons from the slices was observed at 6-24-h intervals. The morphology and growth rates of axons could be easily investigated by light microscopy. Quantification of growth parameters of individual neurites is made easy because no cells migrate out of the slices, so that the outgrowth is not masked by migrating neurons, fibroblasts, glial cells etc. The axons had well-developed growth cones, comparable to those observed in liquid medium; the daily growth rate was on average 318 microns during the 6 days of observation, with a maximum of 1050 microns per day. Back-labelling with a fluorescent dye (DiI) indicated that the longest neurites originated from motoneurons. Our experiments show that axons can develop and grow in a soft agar medium without the need for adding any growth promoting factor or substrate molecule.

Antitumour activity of N6-substituted PMEDAP derivatives against T-cell lymphoma.

The antitumour activity of four N6-substituted PMEDAP derivatives, Me2NEt-PMEDAP, allyl-PMEDAP, Me2-PMEDAP and cypr-PMEDAP, selected on the basis of their in vitro cytostatic activity, was studied in an in vivo model of haematological malignancy of inbred Sprague-Dawley rats. These compounds are believed to serve as the prodrugs of another (phosphonomethoxy)ethyl derivative, PMEG (9-[2-phosphonomethoxy) ethyl] guanine. We compared their toxicity and ability to inhibit tumour development in two different dosage regimes with those of their parent compound PMEDAP, as well with PMEG. The study confirmed the anticancer efficacy of the parental compound PMEDAP. Unlike PMEDAP, its N6-mono- and disubstituted congeners Me2NEt-PMEDAP, allyl-PMEDAP and Me2-PMEDAP were less potent or exhibited the same antineoplastic effect as PMEDAP. cypr-PMEDAP significantly decreased the survival of lymphoma-bearing rats due to high toxicity, which was approximately the same as that of PMEG. Therefore, these acyclic nucleoside phosphonates substituted at the 6-position of 2,6-diaminopurine ring do not seem to be promising drugs for the treatment of haematological malignancies.

Time-dependent influence of procaine hydrochloride on cisplatin antitumor activity in P388 tumor bearing mice.

In previous papers (1,2) we demonstrated that procaine hydrochloride may increase the therapeutic index of cisplatin by an improvement of its antitumor activity and a reduction of its nephrotoxicity. In the present study we investigated the relationship between the antitumor activity obtained by cisplatin associated with procaine hydrochloride and the relative time of administration of these two agents. When procaine hydrochloride (40 mg/Kg body wt) was administered 30 or 120 minutes before cisplatin (16 mg/kg) diluted in normal saline (i.e. clinical condition) it increased, although not significantly, its percent increase in life span (%ILS) and cure rate (%ILS: +292 and +217 vs +150; cure rate: 46.2% and 42.3% vs 23%, respectively), compared to cisplatin alone treatment. These results became statistically significant when procaine hydrochloride was given either simultaneously with cisplatin or 30 and 120 minutes thereafter (%ILS: > 400 vs +150; cure rate: 65.4%, 73.1% and 68% vs 23%, respectively). In conclusion procaine hydrochloride increased the antitumor activity of cisplatin independently from its timing of administration, although it seemed to be a better potentiating agent when administered after cisplatin.