A Target-Based Whole Cell Screen Approach To Identify Potential Inhibitors of Mycobacterium tuberculosis Signal Peptidase

The general secretion (Sec) pathway is a conserved essential pathway in bacteria and is the primary route of protein export across the cytoplasmic membrane. During protein export, the signal peptidase LepB catalyzes the cleavage of the signal peptide and subsequent release of mature proteins into the extracellular space. We developed a target-based whole cell assay to screen for potential inhibitors of LepB, the sole signal peptidase in Mycobacterium tuberculosis, using a strain engineered to underexpress LepB (LepB-UE). We screened 72,000 compounds against both the Lep-UE and wild-type (wt) strains. We identified the phenylhydrazone (PHY) series as having higher activity against the LepB-UE strain. We conducted a limited structure-activity relationship determination around a representative PHY compound with differential activity (MICs of 3.0 μM against the LepB-UE strain and 18 μM against the wt); several analogues were less potent against the LepB overexpressing strain. A number of chemical modifications around the hydrazone moiety resulted in improved potency. Inhibition of LepB activity was observed for a number of compounds in a biochemical assay using cell membrane fraction derived from M. tuberculosis. Compounds did not increase cell permeability, dissipate membrane potential, or inhibit an unrelated mycobacterial enzyme, suggesting a specific mode of action related to the LepB secretory mechanism.

Analgesic treatment and pain killer use in patients enrolled at Pain Control Center Hospice of Solofra (Italy)

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Background: We have evaluated the treatment procedures and the clinical outcome in terms of pain control on 163 consecutive patients enrolled from December 2012 to April 2014 at “Pain Control Center” of the Hospice of Solofra. Methods: The following characteristics have been evaluated: patient gender, mean hospitalization time, differentiation between cancer and non cancer patients (pt.), tumour type, medical weapon use, venous access type, parenteral feeding, transfer in intensive care units, pain killer use. Results: Of the 163 patients (96 males and 67 females, mean age 63.31 years, range: 31-90 years, mean hospitalization time: 29.85 days) 126/163 pt (77.30%) had tumour diseases and 37/163 pt. (22.69%) non cancer diseases. Cancer pt. had lung (24.6%), colo-rectal (17.46%), breast (4.76%), bladder (5.55%), gastric (5.55%), prostate (3.17), hepatocellular (4.76%), pancreas (3.96%), head and neck (4.76%), kidney (3.17%) and other site tumours (19.67%). Patients with tracheostomy were 14/163 (8.58%), with gastrostomy 11/163 (6.74%), with uretero and colostomy 21/163 (12.88%) and with active mechanical ventilator 5/163 (3.06%). The central venous accesses were already present at the moment of the hospitalization in 61/163 pt. (37.42%); during the hospitalization the central venous access were made on 48/163 (29.44%). Seventy-six out of 163 pt. (46.62%) received either total or partial parenteral feeding while 26/163 pt. (15.95%) received enteral feeding. Analgesic therapy with opioids was administered at 131/163 pt. (80.36%) as it follows: morphin in 18.32%; oxycodon/naloxon in 23.63%; codein-paracetamol in 9.16% and transdermic or transmucosal Fentanyl in 48.85% of the pt. The most intensively treated pts. were those with tracheostomy followed by uretero and colostomy. Conclusions: The results of the present study confirm the underestimation of the parenteral feeding and analgesic requirements by pts. with chronic diseases. Another interesting result of the present report is the good clinical benefit achieved with the use of oxycodon/naloxon associated or not with other pain killers. These results are on line with the guidelines that suggest the use of oral slow release opioids.

A dual read-out assay to evaluate the potency of compounds active against Mycobacterium tuberculosis

Tuberculosis is a serious global health problem caused by the bacterium Mycobacterium tuberculosis. There is an urgent need for discovery and development of new treatments, but this can only be accomplished through rapid and reproducible M. tuberculosis assays designed to identify potent inhibitors. We developed an automated 96-well assay utilizing a recombinant strain of M. tuberculosis expressing a far-red fluorescent reporter to determine the activity of novel compounds; this allowed us to measure growth by monitoring both optical density and fluorescence. We determined that optical density and fluorescence were correlated with cell number during logarithmic phase growth. Fluorescence was stably maintained without antibiotic selection over 5 days, during which time cells remained actively growing. We optimized parameters for the assay, with the final format being 5 days' growth in 96-well plates in the presence of 2% w/v DMSO. We confirmed reproducibility using rifampicin and other antibiotics. The dual detection method allows for a reproducible calculation of the minimum inhibitory concentration (MIC), at the same time detecting artefacts such as fluorescence quenching or compound precipitation. We used our assay to confirm anti-tubercular activity and establish the structure activity relationship (SAR) around the imidazo[1,2-a]pyridine-3-carboxamides, a promising series of M. tuberculosis inhibitors.

Levels of heavy metals in liver and kidney of dogs from urban environment

Lead, cadmium and mercury were detected in liver and kidney tissue of dogs from an urban habitat. Samples were digested in a microwave system and analyzed by atomic absorption spectroscopy. Results of the current study showed that at least one of the three heavy metals was detected in tissues of all examined dogs. These findings make us suppose that humans are exposed to the same heavy metals similar to those of dogs that are exposed since they share the same environment. Mercury concentrations detected in kidney of household dogs were higher than stray dogs, therefore the involvement of pet food in exposure to mercury can be supposed.

Levels of heavy metals in liver and kidney of dogs from urban environment

Lead, cadmium and mercury were detected in liver and kidney tissue of dogs from an urban habitat. Samples were digested in a microwave system and analyzed by atomic absorption spectroscopy. Results of the current study showed that at least one of the three heavy metals was detected in tissues of all examined dogs. These findings make us suppose that humans are exposed to the same heavy metals similar to those of dogs that are exposed since they share the same environment. Mercury concentrations detected in kidney of household dogs were higher than stray dogs, therefore the involvement of pet food in exposure to mercury can be supposed.

A multicenter phase II trial of single-agent cetuximab in advanced esophageal and gastric adenocarcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) is overexpressed in a significant proportion of esophageal and gastric carcinomas. Although previous studies have examined tyrosine kinase inhibitors of EGFR, there remains limited data regarding the role of EGFR-directed monoclonal antibody therapy in these malignancies. We carried out a multi-institutional phase II study of cetuximab, a monoclonal antibody against EGFR, in patients with unresectable or metastatic esophageal or gastric adenocarcinoma.

PATIENTS AND METHODS

Thirty-five patients with previously treated metastatic esophageal or gastric adenocarcinoma were treated with weekly cetuximab, at an initial dose of 400 mg/m(2) followed by weekly infusions at 250 mg/m(2). Patients were followed for toxicity, treatment response, and survival.

RESULTS

Treatment with cetuximab was well tolerated; no patients were taken off study due to drug-related adverse events. One (3%) partial treatment response was noted. Two (6%) patients had stable disease after 2 months of treatment. Median progression-free survival and overall survival were 1.6 and 3.1 months, respectively.

CONCLUSION

Although well tolerated, cetuximab administered as a single agent had minimal clinical activity in patients with metastatic esophageal and gastric adenocarcinoma. Ongoing studies of EGFR inhibitors in combination with other agents may define a role for these agents in the treatment of esophageal and gastric cancer.

The morphology and clinical importance of the axillary arch

The axillary arch is the main variation of the axillary muscle. It was first described by Ramsay in 1795. In its classical form, it arises from the latissimus dorsi muscle and extends from this towards the pectoralis major, crossing the base of the axilla and creating a close relationship with the elements of the axillary neurovascular bundle. We describe the finding of 9 axillary arches, including one case of a bilateral arrangement. We develop a searching and finding technique for the axillary arch, essential for the safe and successful development of surgical procedures in the axillary region. Knowledge of this muscle variation and the possibility of finding it during axillary procedures is crucial for lymph node staging and lymphadenectomy and is also important for differential diagnosis in compressive pathologies of the axillary vessels and brachial plexus.

2,3,7,8-Tetrachlorodibenzo-p-dioxin increases Bovine Herpesvirus type-1 (BHV-1) replication in Madin-Darby Bovine Kidney (MDBK) cells in vitro

Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental toxin of current interest. In the last years, higher levels of TCDD than those permitted in UE [European Commission. 2002. European Commission Recommendation 2002/201/CE. Official Gazette, L 67/69] were detected in milk samples from cow, water buffalo, goat, and sheep raised on some areas of Campania Region (South Italy). Dioxin often causes immunosuppression and might render the animal liable to viral infections. In addition, viral infections are able to alter the pattern of dioxin distribution in different organs of the exposed animals. Bovine Herpesvirus type-1 (BHV-1) is a widespread pathogen, which causes infectious rhinotracheitis and infectious pustular vulvovaginitis in cattle. Herein, we have studied the effects of TCDD and BHV-1 infection, in Madin-Darby Bovine Kidney (MDBK) cells, alone as well as in association, so as cellular proliferation, apoptosis, and virus replication. We have observed an increase in cell viability of confluent monolayers at low TCDD concentrations. TCDD treated cells demonstrated increased viability compared to controls as evaluated by MTT test. TCDD exposure increased cell proliferation but induced no changes on apoptosis. Cells exposed to TCDD along with BHV-1 showed a dose-dependent increase in cytopathy, represented by ample syncytia formation with the elimination of the cellular sheets and increased viral titer. These results suggest that TCDD increases viral replication in MDBK cells while BHV-1 further decreases viability of TCDD exposed cells. Since very low concentrations (0.01 pg/ml) are sufficient to augment BHV-1 titer, TCDD may contribute to reactivate BHV-1 from latency, leading to recurrent disease and increase virus transmission.

Crystal structure of (N-tert-butyl-3,4-diphenyl-1,2-oxazetidin-4-yl)methanol, C19H23NO2

C19H23NO2, Pbc21 (no. 29), a = 9.481(1) Å, b = 12.073(1) Å, c = 30.079(5) Å, V = 3443.0 Å3, Z = 8, Rgt(F) = 0.077, wRref(F2) = 0.217, T = 293 K.

Caprine herpesvirus-1 (CapHV-1) induces apoptosis in goat peripheral blood mononuclear cells

Programmed cell death (PCD), or apoptosis, is initiated in response to various stimuli, including virus infection. A number of studies have shown that deregulation of apoptosis is an important feature of virus-induced immunosuppression for various viral diseases. In the present study, CapHV-1 was found to cause apoptosis in mitogen-stimulated as well as nonstimulated caprine peripheral blood mononuclear cells (PBMC). Apoptotic index, as quantified by fluorescent dyes, revealed a significant increase in the percentage of apoptotic cells at 24 and 48 h postinfection as compared to their respective noninfected controls. Apoptosis specific internucleosomal laddering in DNA from CapHV-1 infected PBMC was seen in agarose gel electrophoresis. No DNA fragmentation was observed in control noninfected PBMC. Virus-induced apoptosis was reduced by Z-VAD-FMK, an aspecific caspase inhibitor, by AC-DEVD-CHO (caspase-3-specific) and AC-VEID-CHO (caspase-6-specific) treatment. PCD in CapHV-1 infected peripheral blood mononuclear cells occurs at the G0/G1 phase of the cell cycle. However, penetration of virus particles and infection was not required for PCD, as UV-inactivated CapHV-1 induced apoptosis of mitogen-stimulated bovine peripheral blood mononuclear cells in vitro.

The involvement of oxidative stress in bovine herpesvirus type 4-mediated apoptosis

Bovine herpesvirus type 4 (BHV-4) belongs to the gamma-2-herpesviruses of the Gammaherpesvirinae subfamily. BHV-4 has a worldwide distribution and has been isolated in a variety of clinical diseases as well as from healthy cattle. In this report we demonstrate that BHV-4 induces apoptosis in MDBK cells. In the early phases of apoptosis, cells show an increase in the intracellular level of reactive oxygen species, which is indicative of oxidative stress. This precedes DNA fragmentation, a hallmark typical of apoptosis. Cells were protected from apoptosis only by certain antioxidants (butylated hydroxyanisole and ebselen), whereas N-acetylcysteine turned out to be ineffective. Antioxidants that protected cells from apoptosis prevented oxidative stress but failed to block virus growth. These observations suggest that oxidative stress may be a crucial event in the sequence leading to apoptotic cell death but apoptosis is not required for the multiplication of BHV-4.

Interference of bovine herpesvirus 1 (BHV-1) in sorbitol-Induced apoptosis

In order to determine the ability of bovine herpesvirus type 1 (BHV-1) to suppress apoptosis, we examined the effects of BHV-1 infection on sorbitol-induced apoptosis on Madin-Darby bovine kidney (MDBK) cells. BHV-1 suppresses sorbitol-induced apoptosis in a manner similar to that of herpes simplex virus type 1 (HSV-1), indicating that BHV-1 has one or more anti-apoptotic genes. To elucidate the molecular mechanisms of apoptosis, expression of some genes encoding apoptosis-inhibiting and -promoting factors were analyzed on BHV-1 infected cells during the process of sorbitol-induced apoptosis. Our results revealed that the expression of bcl-2 and bcl-x(L) decreased after 5 and 3 h p.i., respectively; while bax and procaspase-3 expression increased with respect to control as a function of p.i. times and at 7 h p.i. they were not observed. We further show that the expression of p53 gene was also enhanced, suggesting that this apoptotic mechanism is p53 dependent. From these results, we propose that BHV-1 has one or more genes encoding apoptosis-inhibiting factors which interfere with the involvement of bcl-2 gene family members and apoptotic pathway, depending upon caspase-3, triggered by sorbitol.

Activation of the renin-angiotensin system contributes to the peripheral vasoconstriction reflexly caused by stomach distension in anaesthetized pigs

Gastric distension in anaesthetized pigs reflexly elicits peripheral vasoconstriction and an increase in plasma renin activity (PRA), with vagal afferent and sympathetic efferent limbs. The aim of the present study was to quantify the contribution of the renin-angiotensin system to the peripheral vasoconstriction. In pigs anaesthetized with alpha-chloralose, changes in anterior descending coronary, superior mesenteric and left external iliac blood flow caused by stomach distension before and after blockade of angiotensin II receptors with losartan were assessed using electromagnetic flowmeters. Gastric distension for periods of 30 min was performed by injecting 0.8 l warm Ringer solution into balloons positioned within the viscus. Changes in heart rate and renal blood flow were prevented by atrial pacing and injection of phentolamine into the renal arteries, and changes in regional perfusion pressure and in baroreceptor activity were minimized by aortic constriction and denervation of the carotid sinuses. PRA was assessed by radioimmunoassay of angiotensin I. Before blockade of angiotensin II receptors by administration of losartan, stomach distension decreased coronary blood flow by 14.2 % in six pigs and mesenteric and iliac blood flow by 11 % and 17.3 %, respectively, in another six pigs. After administration of losartan, these decreases were significantly reduced to 7.4 %, 6.8 % and 8.7 %, respectively. The above responses were abolished by bilateral section of the subdiaphragmatic vagal nerves. These results show that the peripheral vasoconstriction reflexly caused by stomach distension was significantly contributed to by the concomitant activation of the renin-angiotensin system.

A stereospecific synthesis of oxazolinyloxiranes

Lithiooxiranes 3a and 3b, generated by deprotonation of oxiranes 2a and 2b with s-BuLi at -100 degrees C in Et(2)O, were found to be chemically very stable. trans-Lithiooxirane 3a was also configurationally stable and reacted stereospecifically with electrophiles to give 4a--k. In contrast, cis-lithiooxirane 3b was found to be configurationally much less stable and reacted with electrophiles affording mixtures of diastereomers 4, 7, and 8. After only a very short reaction time, 3b too reacted with electrophiles highly stereospecifically. Deprotonation--deuteration and deprotonation--alkylation of chiral oxazolinyloxiranes 12a and 12b to give oxiranes 12c and 12d were also examined. Semiempirical and ab initio calculations were carried out in an effort to explain the observed stereochemistry.

Modulation of anthracycline activity in canine mammary tumour cells in vitro by medroxyprogesterone acetate

Failure of chemotherapy with anthracyclines as a result of drug resistance and toxicity is a major problem in the clinical management of neoplasia. The aim of the present study was to evaluate the activity of medroxyprogesterone acetate (MPA) as a chemosensitiser on anthracycline cytotoxicity. The study investigated whether such an effect could be related to an increase in lipid peroxidation, nitric oxide production, membrane fluidity and intracellular anthracycline concentration. The results showed that anthracyclines decreased nitric oxide production but increased membrane viscosity (polarisation constant) and lipid hydroperoxide formation in canine mammary tumour cells. Moreover, it was found that both drug-induced cytotoxicity and membrane viscosity increased in the presence of MPA. Conversely, lipid hydroperoxides decreased in MPA-supplemented cells. Medroxyprogesterone acetate did not show any effect on nitric oxide production. The two anthracyclines used (doxorubicin and idarubicin) showed differential intranuclear accumulation in canine mammary tumour cells, and MPA significantly modified intracellular concentration of anthracyclines.

Single nucleotide polymorphisms (SNPs) within Bov-A2 SINE in the second intron of bovine and buffalo k-casein (CSN3) gene

The genetic polymorphism of an entire Bov-A2 element located in the second intron of the buffalo and bovine k-casein (CSN3) gene was investigated by amplification and sequencing of PCR products. Single nucleotide polymorphisms were detected. A PCR-RFLP method was developed to detect an A or G mutation at position 605 of bovine Bov-A2 element which creates a BfaI polymorphic site. The frequencies of the B allele, with the BfaI site, were for 0.275, 0.775, 0.750, 0.975, respectively, for Italian Holstein Friesian, Grey Alpine, Friuli Red Pied and Reggio bovine breeds. The mutation rate (substitutions and deletions/insertions per nucleotide site per year) was 2.5 x 10(-9) for Bov-A2 sequences in the second intron of CSN3. The comparison with other Bov-A2 elements suggests that this retroelement might be an important source of single nucleotide polymorphism for analysis of Bovidae genomes.

Isolation and molecular characterisation of the gene encoding the cytoplasmic ribosomal protein S28 in Prunus persica [L.]] Batsch

RT-PCR was performed on peach (Prunus persica [L.] Batsch) RNA to isolate cDNAs corresponding to transcripts which are differentially expressed in leaves borne on basal and apical shoots. A gene was identified which was more highly expressed in the leaves of basal shoots, and codes for the cytoplasmic protein S28 present in the small ribosomal subunit. The 5' leader regions of RPS28 mRNAs were found to harbour 8-11 pyrimidine tracts, which suggested similarities to regulatory stretches that control the translation of mRNAs for ribosomal proteins in animals. The peach S28 is encoded by two intron-containing genes, which are both transcribed in mitotically active tissues such as developing leaves and roots. In situ hybridisation to shoot vegetative apices and the measurement of nucleus/nucleolus ratios indicated that RPS28 expression was confined to areas undergoing active cell division. The mature RPS28 mRNA was detected as a single species in actively dividing tissues such as apical tips, developing leaves, vegetative buds, stamens, developing fruits and roots. In contrast, accumulation of a precursor RNA, in the presence of the mature product, was found in fully expanded leaves and subtending stems, while only the precursor species was detected in several late-stage tissues. This phenomenon suggested that expression of the mature RNA is controlled at the level of splicing and turnover of the precursor RNA. This is similar to the mode of regulation of ribosomal protein genes in animals.

Medroxyprogesterone acetate increases anthracyclines uptake in chronic lymphatic leukemia cells: role of nitric oxide and lipid peroxidation

Anthracyclines are one of the most used drugs in the therapy of several malignant tumors. Unfortunately, its use is still limited by their cardio-toxicity and by the presence of cancer cells resistant to these drugs. In the present study we evaluated the ability of a chemo-sensitizer agent, MPA (Medroxyprogesterone Acetate), to modify anthracyclines intranuclear uptake in normal leukocytes (NL) and in chronic lymphatic leukemia leukocytes (CLL). Moreover we evaluated the role of lipid peroxidation and nitric oxide (NO) production on antracyclines activity and on their combination with MPA. Our data show that MPA significantly increases anthracyclines uptake only in CLL cells and decreases anthracyclines induced lipid peroxidation.

Ovarian function suppression with a GnRH analogue: D-ser(But[t])[6]-Arzgly[10]-LHRH (Goserelin) in hormone dependent canine mammary cancer

Hormones and hormone level modifying substances have long been used to treat hormone-dependent tumours in humans. Recently, attempts have been made to use hormone manipulation regimens for the treatment of these tumours in veterinary medicine. The aim of the present study was to evaluate the activity of the luteinizing hormone-releasing hormone (LHRH)-agonist, D-ser(But[t])[6]-Azgly[10]-LHRH (Goserelin) in hormone-dependent mammary cancer in dogs. Eighteen female dogs with hormone-dependent mammary cancer (T2-T4, N0, M0 according to TNM clinical staging classification) were selected and allocated into two groups: nine dogs not treated with Goserelin (Group 1) referred to as control; and nine dogs treated with 60 microg/kg depot Goserelin every 21 days for 12 months (Group 2). Goserelin treatment decreased circulating levels of oestradiol and progesterone and reduced the size of mammary tumours; all the animals showed objective response (OR) to treatment after 3 months, and the relapse-free survival after 2 years was 88%. Haematology and blood chemistry parameters, measured every month from the beginning of treatment, as well as physical examination, showed that the drug was without toxic effects. This suggests that, at the dose administered, Goserelin blocks the hypothalamus-pituitary-ovary axis, and consequently can be useful to treat hormone-dependent mammary tumours in female dogs.

Modification of membrane fluidity and depolarization by some anthracyclines in different cell lines

One of the major problems in cancer treatment is the progressive desensitization of cancer cells to chemotherapeutic drugs. Several hypotheses have been advanced to explain this property of cancer cells. In recent years different calcium channel blockers and other chemosensitizing agents like synthetic progestins have been used to revert drug resistance. In our experiments we evaluated the effects of Doxorubicin and Idarubicin on membrane fluidity and depolarization using normal lymphocytes, chronic lymphatic leukemia lymphocytes, normal breast and hormone dependent breast cancer cells and cardiomyocytes. The drugs were used alone or in combination with Verapamil and Medroxyprogesterone acetate. We showed that MPA enhances DOXO and IDA biochemical effects, acting not only on the membrane lipid bilayer, but also on ion channels. VERA instead does not seem to act through the same mechanism.

Age-dependent variations of lactate dehydrogenase and creatine kinase activities in water buffalo calf serum

The electrophoretic patterns of the serum enzymes lactate dehydrogenase and creatine kinase from water buffalo calves are described. Differences in total activities as well as their relative distribution were seen at ages ranging from 1 to 10 weeks. While total lactate dehydrogenase activity increased by over 100%, total creatine kinase increased by almost 400%. The relative activities of lactate dehydrogenase 1 and 5 decreased with age. Lactate dehydrogenase 2 and 3 increased and lactate dehydrogenase 4 did not change. In relation to creatine kinase, the prevalent isoenzyme was creatine kinase-MM, but it's relative activity gradually decreased in comparison to the other two isoenzymes (creatine kinase-MB and creatine kinase-BB). Creatine kinase-BB was completely absent until the 3rd week of age. The percentage modifications of creatine kinase isoenzymes were correlated to age. The results suggest that isoenzymatic separation and characterization of lactate dehydrogenase and creatine kinase in relation to the various tissues can significantly contribute to the diagnosis of diseases which are linked to tissue damage.

Preliminary observations on the interference of antiblastic agents in membrane fluidity and leukocyte potential

A major problem in cancer treatment is the progressive desensitization of the cancer cells to chemotherapeutic drugs. Several hypotheses have been advanced to explain this property of neoplastic cells. In recent years, some calcium-channel blockers have successfully been used to restore drug-sensitivity in previously resistant tumors. The presence of a correlation between ion channels and membrane fluidity is well known. In the ambit of our studies on the activity of several chemotherapeutic drugs on tumors, we have studied the variations in membrane depolarization and fluidity in some leukemic cells as a result of polychemotherapeutic treatments. Our results demonstrate that the membrane fluidity and K(+)-induced depolarization of some types of leukemic cells in patients untreated and treated with some chemotherapeutic agents, are altered significantly as compared to those of normal leukocytes.

The effect of age and sex on the expression of prolactin binding activity in the chicken bursa of Fabricius

The binding of 125I-labeled prolactin (PRL) to membranes from the bursa of Fabricius of male and female chicks of different ages (15-30-45 and 60 days) was studied. In male chicks the binding was very low in 15 day-old animals and slightly increased in more aged animals. In female chicks the binding was more evident in young animals and decreased in 60 day-old animals. The binding showed a hormonal specificity and Scatchard analysis of the binding revealed the presence of binding sites with low capacity and high affinity. The presence of PRL receptors in the bursa of the chick, a structure that confers immunological competence to birds, gives further support to the involvement of the hormone in the immune processes.

Effect of cis-diamminedichloroplatinum (II) on rat thymocyte membrane potential

The effect of cis-diamminedichloroplatinum (II) (cisDDP) on rat thymocytes has been investigated. Changes of anisotropy constant and depolarization of the cell membrane have been determined. The effect of cisDDP on the anisotropy constant has been observed on treated animal thymocytes but not on treated isolated cell membranes. CisDDP inhibits KCl-induced depolarization in isolated rat thymocytes. This inhibiting effect is still present at a concentration as low as 5 microM and it is dose-dependent with a 9.6 microM ED50. CisDDP also boosts the inhibition of the polarization caused by 10 microM tetrodotoxin (TTX) and 10 microM doxorubicin (DOXO). The replacement of Na+ by choline and the inactivation of Ca2+ by EGTA, in the incubation medium, reduces the inhibiting effect of cisDDP on the KCl-induced depolarization. These results suggest that cisDDP induced alterations could be due to the interference of cisDDP with the activity of the ionic channels pertaining to Na+ and Ca2+. This interference is stronger for Na+ channels.

Epidemiological survey of multiple sclerosis in Catania city

The findings of an epidemiological survey of multiple sclerosis (MS) in the urban area of Catania reveal a new and in some respects original pattern of MS cases recorded on 31 December 1989 (prevalence day). They explain why special attention should be paid to patients residing in that area, which shows a remarkable upward trend of the MS prevalence rates calling for further study and for more targeted intervention in the fields of prevention, treatment and rehabilitation.