P10.11.B Re-sensitizing cancer cells to Tumor Treating Fields (TTFields) through PI3K/AKT/mTOR pathway inhibition

Background

Tumor Treating Fields (TTFields) are alternating electric fields disrupting cellular processes critical for cancer cell replication and tumor progression. TTFields therapy is approved for treatment of newly diagnosed glioblastoma (GBM), recurrent GBM, and unresectable malignant pleural mesothelioma, and is currently under clinical investigation for treating other solid tumors, such as ovarian cancer, non-small cell lung carcinoma (NSCLC), and hepatocellular carcinoma (HCC). The research herein aimed to identify potential treatment escape mechanisms and explore the possibility of targeted inhibition of these pathways for re-sensitizing the cells to TTFields.

Material and Methods

GBM U-87 MG, ovarian A2780, and NSCLC H1299 cells were treated with TTFields (1.7 V/cm RMS, 200 or 150 kHz) for continuous long-term application (7 or 13 days, specific conditions depending on the cell line). Changes in signaling pathways in these cells relative to cells exposed to short term TTFields application (3 or 7 days, depending on cell line) were examined by Luminex multiplex assay. Specific pathway markers were examined by immunohistochemistry of tumor sections from sham or TTFields-treated rats bearing N1S1 HCC tumors. TTFields were then co-applied with relevant pathway inhibitors, followed by cell count measurements and western blot examinations for specific pathway markers. The concomitant application of TTFields with a selected inhibitor was tested in mice inoculated orthotopically with MOSE-L firefly luciferase (FFL) ovarian cancer cells. Tumor volume was measured at study end by luciferin signal detection using the In Vivo Imaging System (IVIS).

Results

Cancer cells exposed to long-term application of TTFields displayed decreased sensitivity to TTFields. The PI3K/AKT/mTOR pathway was activated in these cells, with significant increases in AKT and RPS6 phosphorylation levels also observed in HCC tumors from rats treated with TTFields. PI3K inhibitors re-sensitized the cells to TTFields cytotoxicity, with associated down regulation of AKT phosphorylation. Application of TTFields concomitant with the PI3K inhibitor alpelisib resulted in enhanced efficacy in the ovarian cancer mouse model.

Conclusions

The current research demonstrated that PI3K/AKT/mTOR signaling pathway activation was involved in the response to long-term application of TTFields, with increased phosphorylation of key proteins observed both in vitro and in vivo. Concomitant treatment with PI3K inhibitors and TTFields re-sensitized the cells to TTFields, as it alleviated TTFields-induced AKT activation.

Modulation of dopamine tone induces frequency shifts in cortico-basal ganglia beta oscillations

Βeta oscillatory activity (human: 13-35 Hz; primate: 8-24 Hz) is pervasive within the cortex and basal ganglia. Studies in Parkinson's disease patients and animal models suggest that beta-power increases with dopamine depletion. However, the exact relationship between oscillatory power, frequency and dopamine tone remains unclear. We recorded neural activity in the cortex and basal ganglia of healthy non-human primates while acutely and chronically up- and down-modulating dopamine levels. We assessed changes in beta oscillations in patients with Parkinson's following acute and chronic changes in dopamine tone. Here we show beta oscillation frequency is strongly coupled with dopamine tone in both monkeys and humans. Power, coherence between single-units and local field potentials (LFP), spike-LFP phase-locking, and phase-amplitude coupling are not systematically regulated by dopamine levels. These results demonstrate that beta frequency is a key property of pathological oscillations in cortical and basal ganglia networks.

Electrochemical treatment of the pollutants generated in an ink-manufacturing process

The effluents of ink-manufacturing processes contain a large variety of pollutants such as dyes, surfactants, biocides, water soluble solvents, etc. In this work, the electrochemical oxidation of several dyes (methylene blue and rhodamine B), solvents (monoethylene glycol, diethylene glycol and glycerol) and surfactants (sodium dodecylbenzenesulfonate) has been studied. To carry out the electrolyses, a bench-scale plant with a single-compartment electrochemical flow-cell was used. Boron doped diamond (BDD) was used as anode and stainless steel (AISI 304) as cathode. For all the compounds tested, the conductive diamond electrooxidation allows achieving the almost complete removal of COD of the waste with a very high current efficiency. The efficiencies of the electrochemical processes seem to depend on the current density and on the nature of the anions contained in the waste (chlorine, sulphate, phosphate). Thus, it has been observed that the use of chloride media favours the treatment of dyes. On the contrary, the use of sulphate- or phosphate-containing solutions improves the removal of the aliphatic compounds studied (solvents). These results suggest an important role of the mediated electrochemical processes on the overall performance of the reaction system.

Advanced oxidation processes for the treatment of olive-oil mills wastewater

In this work, the treatment of an actual industrial waste with three advanced oxidation processes (AOP) has been studied: conductive-diamond electrooxidation (CDEO), ozonation and Fenton oxidation. The wastewater comes from olive-oil mills (OMW) and contains a COD of nearly 3000 mg dm(-3). CDEO allowed achieving the complete mineralization of the waste with high current efficiencies. Likewise, both ozonation and Fenton oxidation were able to treat the wastes, but they obtained very different results in terms of efficiency and mineralization. The accumulation of oxidation-refractory compounds as final products excludes the use of ozonation and Fenton oxidation as a sole treatment technology. This confirms that besides the hydroxyl-radical mediated oxidation, CDEO combines other important oxidation processes such as the direct electro-oxidation on the diamond surface and the oxidation mediated by other electrochemically formed compounds generated on this electrode.

Electrochemical treatment of the effluent of a fine chemical manufacturing plant

In this work, the electrochemical oxidation of an actual industrial wastewater with conductive-diamond anodes has been studied. The wastewater is the effluent of a fine chemicals plant. This effluent consists of an aqueous solution of solvents (ketones and alcohols) with a high concentration of aromatic compounds coming from the raw materials, intermediates and products of the different processes of the plant and its COD is around 6000 mg dm(-3). The electrolyses were carried out in a discontinuous operation mode under galvanostatic conditions, using a bench-scale plant equipped with a single compartment electrochemical flow cell. The conductive-diamond electrochemical oxidation (CDEO) allowed achieving the complete mineralization of the waste with high current efficiencies. These efficiencies seem to strongly depend on the concentration, pH and temperature but not on the current density (in the range studied). This confirms that besides the hydroxyl radicals mediated oxidation, CDEO combines other important oxidation processes such as the direct electrooxidation on the diamond surface and the oxidation mediated by other electrochemically formed compounds generated on this electrode. Other two advanced oxidation processes (ozonation and Fenton oxidation) have been also studied in this work for comparison purposes. Both technologies were able to treat the wastes, but they obtained very different results in terms of efficiency and mineralization. The efficiency of ozonation and electrochemical oxidation were very similar (especially during the first stages), although the energy consumption required by the electrochemical process to remove at fixed percentage of COD or TOC was significantly smaller than that of ozonation. The possible accumulation of carboxylic acid as final products excludes the use of Fenton oxidation as a sole treatment technology.

Electrochemical oxidation of phenolic wastes with boron-doped diamond anodes

The electrochemical oxidation of several phenolic aqueous wastes has been studied using a bench-scale plant with a single-compartment electrochemical flow cell. Boron-doped diamond materials were used as the anode. Complete mineralization of the waste was obtained in the treatment of phenols not substituted with chlorine or nitrogen. Chlorinated phenolic compounds were transformed into carbon dioxide; volatile organochlorinated compounds and nitro-substituted phenols deal with the formation of polymeric materials. These polymeric materials behave as final products or treatment intermediates depending on the nature of the initial pollutant. The removal of nitro- or the chloro-group from the phenolic molecule seems to be one of the first stages in the treatment. Non-nitrogenated or chlorinated carboxylic acids have been found to be the main intermediates in the electrochemical oxidation of all the phenolic compounds tested. The efficiencies of the process depend strongly on the concentration of organic pollutants and on their nature, and not on the current density, at least in the operation range studied.

Effect of bovine lactoferrin on a transmissible AIDS-like disease in mice

The effect of bovine lactoferrin (bLF) was examined on an AIDS-like disease (ALD) in mice. Induction of disease was achieved by inoculation with infected cell-free plasma from diseased mice to uninfected ones. The effect of treatment with bLF was investigated when administered simultaneously with the virus, 20 days prior to infection, or 20 days after infection. Animals underwent clinical surveillance and enumeration of white blood cells (WBC) and lymphocytes, as well as fluorescent staining of CD4 and CD8 bearing cells. Simultaneous administration of bLF and virus did not affect the pattern of ALD progress along the course of the experiment. Pretreatment with bLF prior to virus inoculation abolished on day 21 the detrimental effect of viral infection that lasted for two months. An opposite outcome was observed when bLF was administered 20 days after the virus. It seems that bLF had played a preventive role for a restricted period of time. However, an adverse response was elicited when bLF was administered 20 days after viral infection.

Reactions of peripheral blood mononuclear cells (PBMC) of camels with monoclonal antibodies against ruminant leukocytes

The particular immune system of the camel has been but little investigated. In this work circulating camel peripheral blood mononuclear cells (PBMC) were studied by flow cytometry. Monoclonal antibodies (mAbs) raised against ruminant leukocytes were used for the detection of cell surface antigens. Monoclonals to T-cell markers, CD4 (CACT138A) and CD8 (CACT80C), exhibited no reactivity towards camel PBMC in contrast to their reactivity to PBMC of other ruminant species and those of cattle in particular. A relatively high percentage (29.1+/-8.9%) of camel PBMC reacted with a non-immunoglobulin cell surface marker, B-B2, comparable to the reactivity of bovine PBMC. The B-B7 cell marker revealed 22.4+/-10.0% of reactive camel PBMC while the CD45 leukocyte common antigen was identified only on 19.4+/-3.1% of camel PBMC as compared to 74.7+/-4.9% for bovine PBMC. IgM (PIg45A) was detected on 9.1+/-1.4% of camel PBMC and on 46.6+/-19.5% of the bovine PBMC. Double fluorescent labeling with two B-cell markers and an anti-ruminant lambda light-chain mAb revealed 7-9% of cells bearing both B and lambda L-chain markers. Light chain reactivity was also assessed using an anti-goat F(ab')(2) antiserum. The values obtained, 14.3+/-5.8% for the camel and 47.8+/-2.7% for the cattle, are close to the values observed for surface IgM. These data suggest that camels, like other ruminants, possess L-chain bearing cells of the B-cell lineage. However, in the camel, Igs are different in that in addition to regular four chain Igs, about 65% of them possess two heavy chain Igs devoid of light chains. Because different sets of V(H) gene segments are used by four and two chain Igs, it is possible that there might be two lineages of B-cells each secreting a different form of antibodies.

[Detection of anomalous origin of left coronary artery by spiral CT as a cause of angina pectoris]

The anomalous origin of the left coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death, especially during exercise. We present a patient in whom the anomalous origin of the left coronary artery is from the right sinus of Valsalva, crossing between the aorta and the pulmonary trunk and causing ischemic chest pain. The anomaly was verified by a Spiral CT, as the coronary angiographic findings were not conclusive, particularly regarding the left course in relation to the major arteries. We suggest that Spiral CT is useful for detecting this kind of anomaly, particularly in clarifying the relationship between the left main coronary artery and the major arteries.

Mitral annulus calcification with a mobile component as a possible source of embolism

Mitral annulus calcification has been associated with embolic events, but the precise pathophysiology has not been elucidated. The authors describe four patients who experienced embolic events whose transesophageal echocardiograms showed a mitral annulus calcification, with a mobile component that exhibited the same echogenicity as the calcification. Three patients had no other conditions known to be associated with embolism. On follow-up transesophageal echocardiography, the mobile component of the mitral annulus calcification had disappeared in three patients. These findings support the hypothesis that mitral annulus calcification not only is associated with but also is possibly a direct cause of embolic events in some patients.

Iatrogenic left ventricular-right atrial fistula following mitral valve replacement and tricuspid annuloplasty: diagnosis by transthoracic and transesophageal echocardiography

Acquired left ventricle-to-right atrium communications are a known complication of valvular heart surgery. Previous reports have described the clinical features and diagnosis using cardiac catheterization. We report two cases of acquired left ventricle-to-right atrium fistula following mitral valve replacement. Particular emphasis is placed on the diagnosis using transthoracic and transesophageal echocardiography, obviating the need for cardiac catheterization before repair.

Comparison of the pharmacokinetics of fosinoprilat with enalaprilat and lisinopril in patients with congestive heart failure and chronic renal insufficiency

AIMS

To compare the serum pharmacokinetics of fosinoprilat with enalaprilat and lisinopril after 1 and 10 days of dosing with fosinopril, enalapril and lisinopril.

METHODS

Patients with congestive heart failure (CHF, NYHA Class II-IV) and chronic renal insufficiency (creatinine clearance </=30 ml min-1 ) were randomized to receive fosinopril, enalapril or lisinopril in two parallel-group studies. In the first study 24 patients were treated with 10 mg fosinopril (n=12 patients) or 2.5 mg enalapril (n=12) every morning for 10 consecutive days. In the second study 31 patients were treated with 10 mg fosinopril (n=16 patients) or 5 mg lisinopril (n=15) every morning for 10 consecutive days. Samples of blood were collected for determination of pharmacokinetic parameters. The area under the curve (AUC) between the first and last days of treatment and the accumulation index (AI) were the primary outcome measures.

RESULTS

All three angiotensin converting enzyme (ACE) inhibitors exhibited a significant increase in AUC between the first and last days of treatment in both studies. The difference between the AI for fosinoprilat (1.41) and enalaprilat (1.96) was statistically significant (95% CI: 1.05, 1.84). Similarly, the difference between the AI for fosinoprilat (1.21) and lisinopril (2.76) was statistically significant (95% CI: 1.85, 2.69). All three ACE inhibitors completely inhibited serum ACE for 24 h. All treatments were well tolerated.

CONCLUSIONS

Fosinoprilat exhibits significantly less accumulation than enalaprilat or lisinopril in patients with CHF and renal insufficiency, most probably because fosinoprilat is eliminated by both the kidney and liver, and increased hepatic elimination can compensate for reduced renal clearance in patients with kidney dysfunction.

Experimental infection of calves with bovine leukemia virus (BLV): an applicable model of a retroviral infection

An experimental model of chronic infection with bovine leukemia virus (BLV) was established in young calves within a relatively short time. In the sera of all infected calves, precipitating antibodies were detected within 5 weeks after infection but upon disease progression pattern of cellular profiles varied. Three calves exhibited transient lymphocytosis 3-5 weeks after infection, two became persistent lymphocytotic (PL+) by that time and one stayed non-lymphocytotic (PL-) for 11 weeks and became PL+ after 4.5 months. Eventually all infected calves became PL+ by the end of the experiment, 6-12 months after infection. Increase of total counts of peripheral blood mononuclear cells (PBMC) related to polyclonal expansion of B-cells. The latter was assessed in all infected calves where the expansion of CD5-bearing cells (B+ CD5+) correlated with increase or decrease of total PBMC counts. Other cell populations such as CD4 and CD8 were also affected. Percentages decreased by 5 weeks after experimental infection to about half their original values though actual cell numbers stayed relatively stable. The experimental model we established compared well with field cases of naturally BLV-infected cattle and thus permitted the investigation of the disease at early stages of infection.

MRI imaging of a left atrial mass misinterpreted by transesophageal echocardiography

Magnetic resonance imaging of the heart was used in a patient with a history of recurrent episodes of transient ischemic attacks in whom a left atrial mass was suspected on transesophageal echocardiography. The use of MRI clarified a diagnosis of a diaphragmatic hernia.

First record in America of Aedes albopictus naturally infected with dengue virus during the 1995 outbreak at Reynosa, Mexico

Mosquito collections were conducted during a dengue outbreak in Reynosa, Tamaulipas, Mexico, July-December 1995. A total of 6694 adult mosquitoes (four genera and nine species) were captured, of which 2986 (78.3% females and 21.7% males) were Aedes albopictus and 2339 (39.7% females and 60.3% males) were Ae.aegypti. These two species comprised 84.2% of the total collection. Specimens were grouped into pools, nearly 50% of them processed for detection of virus by cythopathic effect in C6-36 and VERO cell cultures and by haemagglutination test. Five pools gave positive haemagglutination reactions and were examined by immunofluorescence using monoclonal antibodies to flavivirus and to dengue virus. One pool of ten Ae.albopictus males was positive for dengue virus: serotypes 2 and 3 were identified by serotype-specific monoclonal antibodies and confirmed by RT-PCR. This is the first report of Ae.albopictus naturally infected with dengue virus in America. Also, it is the very first time Ae.albopictus males have been found infected with dengue virus in the wild.

Effect of permeabilization on peripheral blood lymphocytes of bovine leukemia virus (BLV)-infected cattle

Cell surface proteins serve as markers for immunophenotypic characterization of lymphocyte subsets by appropriate monoclonal antibodies and fluorescence-activated cell sorter (FACS) analysis. By the same method, internal antigens or those that are only partially expressed on the cell surface can be determined after permeabilization of the cells. Peripheral blood lymphocytes obtained from bovine leukemia virus (BLV)-infected cattle and from BLV-free cattle were permeabilized and several lymphocyte populations were examined. BoCD4, BoCD8 and three CD4 CD8-T-cell subsets retained their original frequencies after permeabilization in both groups of animals. The recognition of the B-B2 lymphocyte molecule was only partially expressed on the cell surface of intact lymphocytes and was further revealed on permeabilization. The frequency of permeabilized, but not intact, cells stained with this mAb was significantly higher for BLV-infected cattle than for BLV-free animals (P = 0.006). Reactivities of an anti-heat shock protein (Hsp) 70 were measured before and after permeabilization of PBLs. Similar increased cell frequencies were obtained for both groups of bovines. These data indicate that flow cytometry studies should be conducted on both permeabilized and intact cells for a better assessment of protein expression on the cell surface, as well as in the cytoplasm.

Oral clindamycin and ciprofloxacin versus intramuscular ceftriaxone and oral doxycycline in the treatment of mild-to-moderate pelvic inflammatory disease in outpatients

This multicenter, prospective, double-blind study compared the safety and efficacy of clindamycin and ciprofloxacin versus ceftriaxone and doxycycline in the treatment of outpatients with mild to moderate pelvic inflammatory disease (PID) diagnosed by laparoscopy. Samples taken from the endocervix, endometrium, and abdominal cavity before treatment and from the endocervix after treatment were cultured for aerobes, anaerobes, Neisseria gonorrhoeae, and Chlamydia trachomatis. Of the 138 patients enrolled, 131 were evaluable for efficacy. The most prevalent bacteria were streptococci, staphylococci, and Escherichia coli (among aerobes) and Bacteroides species and peptostreptococci (among anaerobes). N. gonorrhoeae was present in 2% (3) of the 131 evaluable patients, and C. trachomatis was in 11% (15). The clinical cure rate was 97% (65 of 67) in the clindamycin and ciprofloxacin group and 95% (61 of 64) in the ceftriaxone and doxycycline group. Side effects were similar in both groups. In conclusion, the two regimens for the outpatient treatment of mild to moderate PID were similarly effective and safe.

The effect of the ingestion of ethanol on obstruction of the left ventricular outflow tract in hypertrophic cardiomyopathy

BACKGROUND

Ethanol causes vasodilation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow tract, in patients with hypertrophic obstructive cardiomyopathy. We assessed the hemodynamic effects of the ingestion of ethanol, in an amount commonly consumed socially, in patients with hypertrophic cardiomyopathy.

METHODS

We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethanol or an isocaloric placebo with the aroma of rum. Each patient received both ethanol and placebo, on different days. The patients, but not the physicians, were blinded to the content of the drink. We measured the sizes of the left atrium and left ventricle, the left-ventricular-wall thickness, blood pressure, heart rate, the degree of systolic anterior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract.

RESULTS

The ingestion of ethanol regulated in a significant drop in the mean (+/- SD) systolic blood pressure (from 130.5 +/- 18.6 to 122.5 +/- 20.3 mm Hg, P<0.001), a significant increase in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1 +/- 26.5 to 62.2 +/- 42.4 mm Hg, P<0.001). These changes, which were not associated with symptoms, did not occur after the ingestion of placebo.

CONCLUSION

The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients with hypertrophic obstructive cardiomyopathy, which could have and adverse clinical effect.

gamma delta T-lymphocytes and anti-heat shock protein reactivity in bovine leukemia virus infected cattle

Bovine leukemia virus (BLV) induces a chronic infection in cattle that may result in persistent lymphocytosis (PL) and, sometimes, enzootic bovine leukosis. The cellular and humoral immune responses of the host following infection have been extensively investigated but little is known about the involvement of gamma delta T-cells in BLV pathogenesis. The affluence of these cells in cattle, and particularly in the peripheral blood of young ruminants, may suggest a particular role for them in defense mechanisms. In this study we have examined circulating gamma delta lymphocytes that express workshop clusters 1 (WC1) and 2 (WC2). In healthy cattle the WC1 cell count tends to decrease with age and adult cattle blood has statistically lower numbers (19.0 +/- 6.6%) than that of young animals (40.1 +/- 7.2%). However, in the blood of BLV-seropositive adult cattle and mainly in BLV+ PL+ animals the population of WC1 cells is elevated compared with uninfected animals (P < 0.007). Likewise, the WC2 cells count is increased (P < 0.01) in BLV+PL+. Furthermore, we have investigated whether BLV infection up-regulates the expression of heat shock proteins (HSP) which in turn could augment the humoral response. Anti-HSP70 activity was examined in the sera of 34 BLV-infected cattle and 40 healthy controls by ELISA. Significantly higher activities (P < 0.001) were observed in BLV-infected cattle.

[Idiopathic myelofibrosis with extramedullary hematopoiesis foci in the skin and testicles. Report of a case]

Idiopathic myelofibrosis (IMF) is a clonal chronic myeloproliferative syndrome characterized by the proliferation of the three haemopoietic series and the marrow connective tissue and by the development of extramedullary haemopoiesis in the liver, spleen and lymph nodes. Cutaneous extramedullary haemopoiesis is an uncommon event and we could not find any reported cases of testicular involvement in this disease. We report the case of a 28 year-old male with diagnosis of idiopathic myelofibrosis in November 1988. During the course of the disease, three years later, he developed a tumor on his right testis. Histologic examination showed extramedullary haemopoiesis with cells of the myeloid, erythroid and megakaryocyte series, in the interstice. Eight months later, numerous red-purple papules and nodules developed on the patients's trunk. The biopsy of a skin lesion revealed an infiltration of the dermis by myeloid, erythroid cells and few megakaryocytes. The patient's clinical condition worsened, and he died in February 1993 following progressive deterioration of the general condition. We describe a case of IFM with extramedullary hemopoiesis involving the skin and the testis pointing out the rarity of these localization.

Magnetic resonance assessment of the pulmonary arterial trunk anatomy, flow, pulsatility and distensibility

We used magnetic resonance imaging with cine velocity mapping to study the anatomy of pulmonary bifurcation and to measure volume blood flow, pulsatility of flow and arterial wall distensibility in the central pulmonary arteries of nine healthy volunteers. Multislice, multiplane spin echo images were acquired to display pulmonary bifurcation anatomy. Diameters of the main pulmonary artery (MPA) in systole were 2.56 +/- 0.35 cm and in diastole 2.20 +/- 0.33 cm. Those of the right pulmonary artery (RPA) were 1.57 +/- 0.29 cm and 1.39 +/- 0.23 respectively, and of the left pulmonary artery (LPA) 1.79 +/- 0.26 cm and 1.55 +/- 0.10 cm respectively. A gradient echo sequence with phase shift velocity mapping was then used to measure flow in MPA, RPA and LPA 2 cm on either side of the pulmonary bifurcation. Time averaged flow, calculated from mean velocity and the cross-sectional area of the vessels was 4.99 +/- 1.10 l.min-1 in MPA, 2.23 +/- 0.58 l.min-1 in RPA and 2.31 +/- 0.63 l.min-1 in LPA. The pulsatility index of flow derived from peak forward flow, peak backward flow and time averaged flow were as follows: MPA 4.4 +/- 0.8, RPA 5.1 +/- 0.6 and LPA 4.6 +/- 1.5. Distensibility, calculated from the change in cross-sectional area between diastole and systole and expressed as percentage were as follows: MPA 25.6 +/- 10.7, RPA 21.4 +/- 10.7 and LPA 24.5 +/- 7.8. MRI with velocity mapping accurately characterized anatomy, flow, distensibility and pulsatility of the central pulmonary arteries.

Circulating immune complexes in bovine leukemia virus (BLV)-infected cattle

Circulating immune complexes (ICs) were detected in the sera of bovine leukemia virus (BLV)-seropositive cattle. Immune complexes were precipitated in 2.5% polyethylene glycol (PEG) and further dissociated. Bovine leukemia virus antigens, IgG and IgM molecules were detected after solubilization in the presence of sodium dodecyl sulphate, and quantitated by enzyme-linked immunosorbent assay (ELISA) assays. Mean values of IgG and IgM in BLV-containing ICs did not significantly differ from those obtained from ICs originating from BLV-seronegative animals. However, differences were found in the composition of ICs from older BLV-positive animals as compared to those obtained from young animals. The ratio of IgG/IgM was 5.02 in animals aged 5-10 years, while this ratio was 11.66 in animals of less than 5 years of age and 10.19 in controls. This might indicate a possible increase in the contribution of IgM molecules to the structural composition of ICs in BLV-infected cattle as related to age or stage of infection.

Bioequivalence of quinidine in two sustained-release preparations

The bioequivalence of two sustained-release preparations of quinidine bisulphate from Teva (Israel) and from Astra (Sweden) was assessed in an acute, single-dose randomized cross-over study in seven healthy subjects. There was no significant difference in time to peak, peak serum concentration, area under the concentration time curve from 0 to infinity, and the fraction absorbed between quinidine bisulphate 500 mg from Teva and from Astra. In addition, quinidine bisulphate 250 mg from Teva was compared with the short-acting quinidine sulphate 200 mg. The quinidine bisulphate from Teva had a significantly P less than 0.025) decreased peak serum concentration and an increased time to peak compared with the short-acting quinidine sulphate, although these two drugs are similar for the area under the curve from 0 to infinity. Our pharmaceutical records show that 85% of outpatients receiving quinidine are given the sustained-release quinidine bisulphate. However, only 36% of the outpatients prescribed sustained-release quinidine bisulphate are appropriately prescribed for twice-daily treatment. Thus the quinidine bisulphate from Teva is a sustained-release preparation with bioequivalence to the reference sustained-release preparation and can be administered twice daily.

A lactogenic-immune-deficiency-syndrome in cows: unexplained phenomenon

The majority of adult cows in a certain dairy herd, were found to have very low levels of immunoglobulins (Igs) in their colostrum. This phenomenon was defined by us as Lactogenic-Immune-Deficiency-Syndrome (LIDS). The mean IgG levels were 44.5 and 57.2 mg ml-1 respectively (on two different occasions) as compared to that of a control group which was 103.4 mg ml-1. The levels of Igs in the colostra of heifers from the same herd were found to be higher than those of adult cows. The degree of LIDS was found to be closely related to the age of cows in the herd. The low levels of Igs in the colostra were not directly linked to their concentrations in the sera of the affected cows. The relatively low amount of IgA in the affected colostra suggests that the local production in the lymph tissue associated with the mammary glands is impaired as well. In order to investigate the etiology of the phenomenon, tests were carried out to reveal whether bovine leucosis virus (BLV) infection or immune complexes were involved in the pathogenesis of LIDS. The results were negative. The etiology of LIDS remains for the time being unknown.

IgM rheumatoid factor in cattle immunized against babesiosis

Polyclonal bovine IgM-rheumatoid factors (IgM-RFs) were examined in sera of cattle immunized against babesiosis. An enzyme-linked immunosorbent assay (ELISA) was used enabling rapid screening of serum samples. Results obtained indicate a rise of serum IgM-RF levels with age in healthy bovines. However when animals of similar age and pertaining to the same herd were examined, levels of serum IgM-RF exhibited a wide distribution range. Mean values in 60 sera of 2 yrs old clinically healthy heifers originating from a single herd were of 452.60 +/- 201.26 e.u. at 1 in 1,000 serum dilution and of 202.37 +/- 137.86 e.u. at 1 in 4,000 serum dilution. In a herd where repeated vaccination of dams against babesiosis was carried out 3 to 6 weeks before delivery either with live Babesia bovis parasites or soluble antigens of in vitro grown organisms, no significant differences in mean IgM-RF values were found between revaccinated animals and a control group. Nor did the mean values of serum IgM-RF of calves born to the respective groups of dams exhibit significant differences. It thus appears that immunization of healthy cattle against this parasite does not affect mean serum IgM-RF levels.

Magnetic resonance characterization of pulmonary arterial blood flow after single lung transplantation

Magnetic resonance imaging has been used to study pulmonary arterial anatomy and to measure pulmonary arterial blood flow in patients with single lung transplantation. Nine patients and nine control subjects matched for age and sex were studied. The anatomy of the main pulmonary artery and its main branches, as well as the site of arterial anastomoses, was identified and measurements of their diameters were taken. There were no significant differences in diameters of these vessels between the patients and the control subjects. Arterial blood flows to the transplanted lung were 2.07 +/- 0.45 L/min/m2 in the group with right lung transplantation and 2.43 +/- 0.60 L/min/m2 in those with left lung transplantation compared with 1.22 +/- 0.22 L/min/m2 and 1.27 +/- 0.41 L/min/m2 in the control group, respectively. The ratio of blood flow in the transplanted and the native lungs in all patients studied was 2.8 +/- 0.83:1. The flow profile in the artery of the transplanted lung showed a wide forward flow during systole and most of diastole, whereas that of the native lung showed a narrow early systolic peak and a reverse flow in most of diastole. These differences in the volume and pattern of flow in the transplanted lung are most likely related to the relative resistance in the native and the transplanted lung and could constitute an additional index for monitoring the condition of patients with lung transplantation and help in the understanding of the physiology of the denervated pulmonary vascular bed.

[Usefulness of laryngeal stroboscopy]

The extended use of optic fibers and TV cameras and videos make easier the stroboscopic exploration of the vocal folds. The ENT surgeons must stress the use of this unique method which allows us the study of the laryngeal voice function. This exploration is based on a fictional slow motion movement of the vocal fold that lets us see the mucosal wave. The most useful clinical implications of the laryngeal stroboscopic study are: phonatory function, differential diagnosis between benign and malignant lesions and laryngeal paresis.

Clinical pharmacokinetics of five oral cephalosporins in calves

The minimal inhibitory concentrations (MIC) of cephalexin, cephradine, cefaclor, cefatrizine and cefadroxil for Salmonella species, Escherichia coli and Pasteurella multocida isolated previously from young calves were determined. The MIC90 values for cephalexin, cephradine and cefadroxil ranged between 3.12 micrograms ml-1 and 12.5 micrograms ml-1, whereas those of cefatrizine and cefaclor were 3.12 micrograms ml-1 and 0.78 microgram ml-1, respectively. Each drug was administered intravenously and orally to groups of pre-ruminating calves and orally to early ruminating calves. Although the pharmacokinetic characteristics of the drugs after intravenous injection were similar to other beta-lactam antibiotics, significant differences between the cephalosporins examined were found in respect of certain kinetic parameters. The drugs showed rapid absorption into the systemic circulation after oral administration to pre-ruminating calves but the elimination half-life values (t1/2 beta) varied between three hours (cefaclor and cefadroxil) and nine hours (cefatrizine). The bioavailability of the drugs was about 35 per cent of the administered dose. Co-administration of probenecid with each antibiotic caused a twofold or greater increase in peak serum drug concentrations (Cmax) but the effect on t1/2 beta was variable. Cephalexin, cephradine and cefaclor given to the ruminating calves resulted in very low serum or plasma concentrations and their use should be restricted to younger calves. Cefadroxil was found to give the highest serum concentrations in this age group but had significantly lower bioavailability when compared with the unweaned calves. Provisional oral dosage regimens were computed for each cephalosporin on the basis of the MIC data and the kinetic parameters derived from intravenous and oral drug administration.

Clavulanate-potentiated amoxycillin: in vitro antibacterial activity and oral bioavailability in calves

The minimal inhibitory concentrations (MIC) of amoxycillin and clavulanate-potentiated amoxycillin (amoxycillin:clavulanic acid, 4:1 by weight) were compared for 171 Salmonella, 170 Escherichia coli, and 32 Pasteurella isolates recovered from infected neonatal calves. In the presence of clavulanic acid, the MIC of amoxycillin was reduced to levels less than or equal to 12.5 micrograms/ml for all the Salmonella group B, all the Pasteurella, and for 12 out of the 44 E. coli isolates which were resistant to amoxycillin (MIC greater than or equal to 100.0 micrograms/ml). For isolates sensitive to amoxycillin (MIC less than or equal to 1.56 microgram/ml) there was no change in MIC values in the presence of clavulanic acid. A small proportion of Salmonella and E. coli isolates were resistant to clavulanate-potentiated amoxycillin. In a cross-over trial involving 10 preruminant (2 weeks old) calves, amoxycillin trihydrate and clavulanate-potentiated amoxycillin were administered orally at 10 mg/kg. An analysis of serum amoxycillin level data showed that the pharmacokinetic parameters t1/2ab, Cmax, t1/2 beta, AUC, Cp degree, and f' (estimated drug absorption ratio) were the same after treatment with amoxydrate and clavulanate-potentiated amoxycillin. Administration of clavulanate-potentiated amoxycillin and probenecid resulted in elevation and prolongation of serum amoxycillin levels. Computations showed that in preruminant calves serum amoxycillin concentrations sufficient to inhibit sensitive pathogens can be maintained by oral clavulanate-potentiated amoxycillin treatment at 10 mg/kg TID. At two times that dose rate serum drug concentrations capable of inhibiting 50% of all types of pathogens examined can be maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacology of mecillinam in calves

The minimal inhibitory concentrations (MIC) of mecillinam, a novel beta-amidinopenicillanic acid derivative with unusual activity against Gram-negative bacteria, were compared with the MIC of cephazolin, cephalothin, amoxycillin, oxytetracycline, chloramphenicol, dihydrostreptomycin, neomycin, kanamycin, gentamicin and sulfadoxin/trimethoprim (TMP) against pathogenic Gram-negative bacteria recovered from neonatal calves. The MIC values of mecillinam ranged between 0.05 microgram/ml and 12.5 micrograms/ml, and the MIC90 values were 1.56 micrograms/ml and 3.12 micrograms/ml. The activity of mecillinam against salmonella, Escherichia coli and Pasteurella multocida was similar to or slightly greater than the activities of the first-generation cephalosporins, gentamicin and sulfa/TMP. Mecillinam concentrations less than or equal to 3.12 micrograms/ml inhibited the growth of the majority of isolates which were resistant (MIC90 greater than 100 micrograms/ml) to the other antibiotics studied. The minimum bactericidal concentration (MBC) values of mecillinam were two- to three-fold higher than the MIC values. The two-compartment open model was appropriate for the analysis of serum mecillinam concentrations measured after intravenous administration. The distribution half-life (t1/2 alpha) was 11.7 min, the elimination half-life (t1/2 beta) was 53.3 min, and the apparent volume of distribution (Vd (area)) and the distribution volume at steady state (Vd (ss)) were 0.568 and 0.896 l/kg, respectively. The drug was quickly absorbed after intramuscular (i.m.) injection; peak serum drug concentrations were directly related to the dose administered. They were obtained 30 min after treatment and the i.m. t1/2 was approximately 65 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple pulmonary hamartomas; a case report and review of the literature

Bilateral multiple hamartomas were found in a woman suspected of having metastatic malignancy of the lung. As extensive investigation for the primary tumour was unrevealing, a left exploratory thoracotomy and histological examination established the diagnosis. In view of the benign character of the tumours, local excision alone was performed. No surgical intervention was performed on the right side. Repeat chest films 12 months after surgery did not show the appearance of new lesions in the left lung or any increase in the size of the nodules in the right lung. This is the 12th case so far reported. The clinical characteristics and surgical management of these tumours are discussed.