Gastrointestinal parasites in captive olive baboons in a UK safari park

From the safety inside vehicles, Knowsley Safari offers visitors a close-up encounter with captive olive baboons. As exiting vehicles may be contaminated with baboon stool, a comprehensive coprological inspection was conducted to address public health concerns. Baboon stools were obtained from vehicles, and sleeping areas, inclusive of video analysis of baboon–vehicle interactions. A purposely selected 4-day sampling period enabled comparative inspections of 2662 vehicles, with a total of 669 baboon stools examined (371 from vehicles and 298 from sleeping areas). As informed by our pilot study, front-line diagnostic methods were: QUIK-CHEK rapid diagnostic test (RDT) (Giardia and Cryptosporidium), Kato–Katz coproscopy (Trichuris) and charcoal culture (Strongyloides). Some 13.9% of vehicles were contaminated with baboon stool. Prevalence of giardiasis was 37.4% while cryptosporidiosis was <0.01%, however, an absence of faecal cysts by quality control coproscopy, alongside lower than the expected levels of Giardia-specific DNA, judged RDT results as misleading, grossly overestimating prevalence. Prevalence of trichuriasis was 48.0% and strongyloidiasis was 13.7%, a first report of Strongyloides fuelleborni in UK. We advise regular blanket administration(s) of anthelminthics to the colony, exploring pour-on formulations, thereafter, smaller-scale indicator surveys would be adequate.

ON LIVER FLUKE (FASCIOLA HEPATICA) IN CAPTIVE VICUÑAS (VICUGNA VICUGNA) AT KNOWSLEY SAFARI, PRESCOT, UNITED KINGDOM

Knowsley Safari (KS), Prescot, United Kingdom houses a variety of captive exotic ungulates. As part of their animal welfare plan, a prospective coprological survey was undertaken for liver fluke. In June 2021, 330 fecal samples, representative of 18 exotic ungulate species, were processed by sedimentation and filtration, with examination by coproscopy. Finding fascioliasis in all five vicuña alone, with fecal egg counts ranging from one to eight eggs per gram, anthelminthic treatment was attempted twice, with three coprological reviews. While the first anthelminthic treatment (oxyclozanide) was equivocal, the second anthelminthic treatment (triclabendazole) was proven effective upon two later follow-ups. An initial malacological survey of 16 freshwater sites in KS, first found Galba truncatula at two sites in June 2021, then upon more extensive searching subsequently within the vicuña's enclosure. It appears that F. hepatica was locally acquired, being the first report of fascioliasis within captive vicuñas in the United Kingdom. To develop a better fluke-management plan, regular coprological and malacological surveillance is justified, perhaps with molecular xenomonitoring of snails, alongside prompt administration of appropriate flukicide as required.

The winds from HL Tau

Outflowing motions, whether a wind launched from the disc, a jet launched from the protostar, or the entrained molecular outflow, appear to be a ubiquitous feature of star formation. These outwards motions have a number of root causes, and how they manifest is intricately linked to their environment as well as the process of star formation itself. Using the Atacama Large Millimeter/submillimeter Array (ALMA) Science Verification data of HL Tau, we investigate the high-velocity molecular gas being removed from the system as a result of the star formation process. We aim to place these motions in context with the optically detected jet, and the disc. With these high-resolution (∼1 arcsec) ALMA observations of CO (J=1-0), we quantify the outwards motions of the molecular gas. We find evidence for a bipolar outwards flow, with an opening angle, as measured in the redshifted lobe, starting off at 90°, and narrowing to 60° further from the disc, likely because of magnetic collimation. Its outwards velocity, corrected for inclination angle is of the order of 2.4 km s^-1.

Development of the nano-dust analyzer (NDA) for detection and compositional analysis of nanometer-size dust particles originating in the inner heliosphere

A linear time-of-flight mass spectrometer is developed for the detection and chemical analysis of nanometer-sized particles originating near the Sun. Nano-dust particles are thought to be produced by mutual collisions between interplanetary dust particles slowly spiraling toward the Sun and are accelerated outward to high velocities by interaction with the solar wind plasma. The WAVES instruments on the two STEREO spacecraft reported the detection, strong temporal variation, and potentially high flux of these particles. Here we report on the optimization and the results from the detailed characterization of the instrument's performance using submicrometer sized dust particles accelerated to 8-60 km/s. The Nano Dust Analyzer (NDA) concept is derived from previously developed detectors. It has a 200 cm(2) effective target area and a mass resolution of approximately m/Δm = 50. The NDA instrument is designed to reliably detect and analyze nanometer-sized dust particles while being pointed close to the Sun's direction, from where they are expected to arrive. Measurements by such an instrument will determine the size-dependent flux of the nano-dust particles and its variations, it will characterize the composition of the nano-dust and, ultimately, it may determine their source. The flight version of the NDA instrument is estimated to be <5 kg and requires <10 W for operation.

Relationship of adipokines and non-esterified fatty acid to the insulin resistance in non-diabetic individuals

BACKGROUND

Altered secretion of adipokines and non-esterified fatty acid (NEFA) seems to play a pivotal role in the abdominal obesity-related insulin resistance (IR).

AIM

To determine semi-quantitatively the impact of serum NEFA, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), leptin, adiponectin, and resistin levels on IR measured by homeostasis model assessment (HOMA-IR). MATERIAL/SUBJECTS: Seventy-four Caucasian subjects forming 3 age-, and sex-matched groups were included into the study [Group 1 and 2: non-diabetic obese patients, no.= 25, body mass index (BMI): 28-39.9 kg/m(2), no.=25, BMI≥40 kg/m(2), respectively, and Group 3: 24 healthy, normal weight control subjects].

METHODS

Serum levels of NEFA and adipokines as well as other metabolic variables including HOMA-IR were measured.

RESULTS

HOMA-IR was associated positively with BMI, waist circumference, serum NEFA, leptin, IL-6, and TNF-α levels, negatively with adiponectin, with no significant relation to resistin. In multiple regression analyses, of these factors leptin was a strong, IL-6 and adiponectin were weak independent predictors of HOMA-IR, while the others were not significant determinants of HOMA-IR. However, even together, they explained only 35-36% of variance of HOMAIR.

CONCLUSIONS

Although IR has associations with many of the investigated parameters, of these, only serum level of leptin, and in lesser degree IL-6 and adiponectin are independent determinants of the severity of IR. Moreover, even together they explain only a minority of variance IR.

[Intraabdominal dermoid cyst in the differential diagnosis of ascites]

HISTORY

A 60- year-old Hungarian woman known to be alcohol-dependent, consulted her family physician because of generalized weakness and an enlarged abdomen Her doctor started diuretic treatment assuming that liver cirrhosis with ascites was the cause. After three months she was referred to our hospital because of dyspnea and orthopnea as well as edema in the legs.

FINDINGS

On admission to the Department of Medicine, Elizabeth Hospital in Sopron (Hungary) the patient was in a critical condition with severe cachexia, muscular atrophy and no palpable adipose tissue. Her abdomen was severely distended by a large amount of abdominal fluid. Abdominal paracentesis was performed, which revealed feculent and fatty shining fluid.

INVESTIGATION

Laboratory tests showed low levels of total protein, albumin, cholesterol and iron. Microcytic anemia, leucocytosis and a high erythrocyte sedimentation rate were also found. Transaminases, urea, creatinine, lipase, amylase and electrolytes were within normal range. Protein and lipid levels of the abdominal fluid were high.

DIAGNOSIS AND TREATMENT

Abdominal ultrasound and computed tomography (CT) were performed after hemodynamic stability and normal blood pressure had been achieved. Abdominal ultrasound showed that the abdominal cavity was full of fluid, which contained numerous round shiny objects with a capsule-like covering. Abdominal CT confirmed that the abdomen contained a partly cystic mass within which there were round objects, about 3 cm in diameter. These findings established the diagnosis of dermoid cyst. The patient died five hours after admission. At autopsy there was evidence of organ compression, severe malabsorption and malnutrition, pulmonary congestion, and myocardial atrophy.

CONCLUSION

In a patient with ascites, liver cirrhosis or intraabdominal having been ruled out, an intraabdominal dermoid cyst should be considered in the differential diagnosis. The outcome in this patient was largely determined by her failure to consult a doctor early, having failed to appreciate the seriousness of her condition.

Cancerous hyper-mutagenesis in p53 genes is possibly associated with transcriptional bypass of DNA lesions

The database of tumor-associated p53 base substitutions includes about 5% of tumors with two or more base substitutions. These multiplet base substitutions in one tumor are evidence for hyper-mutagenesis. Our retrospective analysis of this database indicates that most multiplets arise from a single transient hyper-mutagenic event in one cell that subsequently proliferated into a clonal tumor. The hyper-mutagenesis, 1.8 x 10(-4) substitutions per base pair, is detected as multiple mutations in p53 genes of tumors. It requires one strongly tumorigenic p53 substitution, usually missense, called the driver mutation. The occurrence frequencies of ancillary base substitutions, those that hitch-hike along with the driver mutation, are independent of their amino acid coding properties. In this respect, they act like neutral mutations. In support of this neutrality, we find that the frequency distribution of hitch-hiking CpG transitions along the p53 exons, their mutational spectrum, approximates the spontaneous pre-selection mutational spectrum of most human tissues and is correlated with the mutational spectrum of p53 pseudogenes in mammalian germ cells. The driver substitutions of multiplets predominantly originate along the transcribed strand while the ancillary substitutions tend to originate along the non-transcribed strand. This data is consistent with a model of time-dependent mutagenesis in non-dividing stem cells for generating multiple strand-asymmetric p53 mutations in tumors. By transcriptional bypass of DNA lesions with concomitant misincorporation, transcriptional mutagenesis generates a transient mutant p53 mRNA. The associated mutant p53 protein could allow the host cell a growth advantage, release from G1-arrest. Then, during subsequent DNA replication and misreading of the same lesion, the damaged base along the transcribed DNA strand would serve as the origin of the p53 base substitution that drives the hyper-mutagenic event leading to tumors with multiple p53 mutations.

The effect of osmolality changes on gastric mucosal endogenous prostacyclin levels in drug-induced experimental ulcer model of rat

Osmolality changes evoked with intragastric administration of natural honey or mannitol, significantly decreased the gastric ulceration of rats induced by indomethacin. Together with this effect, a parallel increase was detectable in the mucosal level of endogenous prostacyclin. Although many processes may be involved in this phenomenon, the authors explain their data with a stimulating effect on gastric mucosal microcirculation due to osmolality changes.

Gastric mucosal endogenous prostacyclin levels are different in Brattleboro rats compared with Wistar strain

Homozygous Brattleboro rats were investigated and compared to normal (physiological) Wistar strain rats regarding their gastric mucosal endogenous prostacyclin (PG-I(2)) level. It seems that the Brattleboro animals have a significantly lower level of this important protective material. Wistar rats having an artificial pituitary stalk lesion (which is the artificial equivalent of homozygous Brattleboro animals) showed no differences in endogenous mucosal prostacyclin level compared to normal Wistar rats. Therefore, we concluded that this hitherto unknown property of the homozygous Brattleboro rats is genetically determined.

Acquired Bernard-Soulier syndrome: a case with necrotizing vasculitis and thrombosis

We describe a patient with positive antinuclear antibodies, polyclonal gammopathy and high level of circulating immunocomplexes, resulting in vascular purpura. In addition, the patient had a slightly prolonged bleeding time and an isolated defect of ristocetin-induced platelet aggregation (RIPA) in platelet-rich plasma (PRP). The patient's plasma also inhibited RIPA in normal PRP and in normal platelet suspension. The activity and multimeric structure of plasmatic von Willebrand factor showed no alteration. We could demonstrate an autoantibody against platelet membrane glycoprotein (GP) Ib, using an ELISA-type assay. These data suggest an acquired Bernard-Soulier syndrome. We suggest that the patient had an immunocomplex-mediated leukocytoclastic vasculitis accompanied by production of antinuclear autoantibodies as well as the presence of an autoantibody against GPIb. The titer of the anti-GPIb antibody, however, was too low to induce significant platelet-type bleeding tendency, only laboratory alterations were found. Moreover, in a later stage of her disease, she developed a severe necrotizing vasculitis which was followed by a deep venous thrombosis.

Soft drugs. 12. Design, synthesis, and evaluation of soft bufuralol analogues

In the search for more potent but still short-acting beta-blockers (BB), the methyl, ethyl, isopropyl, tert-butyl, cyclohexyl, 2-(1-adamantyl)ethyl, and methylthiomethyl esters of the acidic inactive metabolite of bufuralol were synthesized based on the "inactive metabolite" approach. The cleavage of the ester bond by blood and tissue esterases rapidly deactivates these compounds, resulting in an ultrashort duration of action. The beta-antagonist potencies and time courses of actions of the new "soft" BBs were characterized by recording ECG and intra-arterial blood pressure (BP) in rats. In the isoproterenol-induced tachycardia model, while bufuralol at an iv dose of 1 mg/kg (3.8 micromol/kg) diminished heart rate (HR) for at least 2 h, the effects of the soft drugs lasted for only 10-30 min at equimolar dose. The inactive metabolite did not decrease HR significantly. The first four members of this series of compounds showed the highest beta-blocking potencies, ranging between 25% and 50% of that of bufuralol. Next, the effects of these most active compounds on resting HR and BP were evaluated in comparison to esmolol. Infused for 10 min at a rate of 20 micromol/kg/min, esmolol decreased HR and mean arterial pressure (MAP) by 40% and 60%, respectively. The soft drugs at doses ranging only between 2 and 4 micromol/kg/min resulted in a 20-40% decrease in HR and a 30-50% reduction in MAP. However, the time courses of both the bradycardic and hypotensive effects of the soft drugs were superimposable to that of esmolol, diminishing within 60 min after the discontinuation of the infusions.

Design, synthesis, and pharmacological evaluation of soft glycopyrrolate and its analog

Glycopyrrolate is a quaternary anticholinergic drug. Like for other anticholinergics, the usefulness of this agent is limited by its side effects. In this study, based on the structure of glycopyrrolate, we designed a soft drug, methoxycarbonylphenyl-cyclopentylacetoxy-N,N-dimethyl-3-p yrrolidinium methyl sulfate (SG), and its analog, methoxycarbonylphenylcyclopentyl-acetoxyethyl-N,N,N-trimethylammon ium methyl sulfate (SGA). These soft drugs are expected to be locally active, but systemically inactive in order to increase therapeutic index. SG and SGA were synthesized by (i) carboxylation of methyl phenylcyclopentylacetate, (ii) esterification with N-methyl-3-pyrrolidinol (for SG) or 2-chloro-N,N-dimethylaminoethane (for SGA), and (iii) quarternization with dimethyl sulfate. Receptor binding studies demonstrate that SG has muscarinic subtype selectivity (m3/m2). Guinea pig ileum pA2 assay indicates that activity of SG is moderate, and SG is about ten times more potent than SGA. The in vivo characterization of SG and SGA, both in mydriasis tests and in prevention of carbachol induced bradycardia, supported its soft nature. Applying SG or SGA into rabbit eyes, the dilation of the contralateral (water-treated) pupils was not observed. Glycopyrrolate application, however, caused dilation of the contralateral pupil, indicating a systemic effect of this drug. Cardiac studies were carried out by evaluating the protective effect of soft anticholinergics against carbachol induced bradycardia. The results indicate that SG and SGA were as potent as atropine-MeBr in preventing carbachol induced bradycardia in the rat; however, their durations of action were significantly shorter. In conclusion, the newly synthesized SG and SGA showed soft nature in the body. They are anticholinergics with subtype selectivity and moderate potency, and can be used as topical antiperspirants.

Detection of tyrosinase mRNA in melanoma by reverse transcription-PCR and electrochemiluminescence

Increased sensitivity and improved quantitation of analytical tests used in biotechnology and clinical chemistry are goals of many laboratories. We have used tyrosinase primers to specifically amplify by RT-PCR the tyrosinase mRNA expressed by the M12 melanoma cell line in a background of mRNA from breast cancer cells. An electrochemiluminescence detection procedure was used as a readout system for this study. Biotinylated post-PCR cDNA samples were hybridized to a tris(2,2'-bipyridine)ruthenium(II) (TBR) chelate-labeled oligonucleotide probe, and the hybrid was subsequently captured by streptavidin-coated Dynabeads. When either the QPCR System 5000 or the Origen 1 Analyzer System were used, the luminescence emitted by the TBR-chelate of the captured specific post-PCR product was assessed. Tyrosinase-specific mRNA isolated from approximately 1-10 melanoma cells in a background of 10(7) cells could be detected. We improved the sensitivity and logistics of the assay through the use of rTth for reverse transcription and amplification. Tyrosinase mRNA was detected in blood from 7 of 16 melanoma patients, whereas none of the 5 healthy donor bloods were positive (P = 0.01; Wilcoxon test).

Development of standard reference materials for diagnosis of p53 mutations: analysis by slab gel single strand conformation polymorphism

We have amplified by polymerase chain reaction (PCR) a 2.0 kbp region of the p53 gene containing exons 5--9 from seven cell lines reported in the literature to contain the majority of mutations reported for this gene. Sequence analysis of these products show that all seven cell lines contain mutations within the mutational hot spots of the p53 gene. Six of the seven clones have single base substitutions and the seventh has a single base deletion. We have analyzed the seven p53 single point mutations by single strand conformation polymorphism (SSCP) analysis using fluorescence slab gel electrophoresis (SG-SSCP). Fluorescent-labeled PCR primers were used for amplification of specific exons for mutation detection. SG-SSCP was conducted using Model 373 and Model 377 DNA sequencers with GeneScan Software (Perkin Elmer, Applied Biosystem Division). Nine different gel systems were first tested for their ability to resolve the p53 mutations using the Model 373 instrument. Two gel systems were capable of resolving all of the mutations that were screened. Optimal results were obtained with 12% w/v acrylamide 50:1 plus 10% v/v glycerol. This gel system was used to evaluate the effect of temperature on the ability to resolve the mutations. The separation with respect to wild type varied for each mutation examined. Subambient temperature (20 degrees C) was preferable overall for discrimination of these mutations as a group. We intend to use this system to examine a much larger panel of p53 mutation standards that are now under development.

Active site-directed thrombin inhibitors: alpha-hydroxyacyl-prolyl-arginals, new orally active stable analogues of D-Phe-Pro-Arg-H

D-alpha-Hydroxyacyl-prolyl-arginals, a new type of analogues of D-Phe-Pro-Arg-H (R1), have been prepared and evaluated. Unlike R1, whose terminal group is NH2, the new analogues with a terminal OH group are stable, as are the N-substituted derivatives of R1, that is, D-MePhe-Pro-Arg-H (R2), the highly potent and selective thrombin inhibitor, and Boc-D-Phe-Pro-Arg-H (R3), the much less favorable analogue. The most notable of the new analogues corresponds to the general formula D-Xaa-Pro-Arg-H, wherein Xaa means the acyl residue of mandelic acid (Man, 1), diphenyllactic acid (Dpl, 2), hexahydrophenyllactic acid (Hpl, 3), or hexahydromandelic acid (Hma, 4). In plasma clotting assays, 1 to 4 appeared to inhibit thrombin as well as some other clotting enzymes involved in thrombin generation, whereas R1 and R2 seemed to produce anticoagulation through inhibition of thrombin only. In the fibrin plate assay, 1 to 4 possessed even more moderate antifibrinolytic activities than R2. In in vivo evaluation in rats and rabbits, 2 to 4 proved to be potent anticoagulants/antithrombotics even on oral administration in a dose of 5 mg/kg. In view of these findings with the alpha-hydroxyacyl-prolyl-arginals, it is very likely that the less favorable biologic properties of Boc-D-Phe-Pro-Arg-H are due to the hydrophobicity and bulkiness of the terminal Boc-NH rather than its neutrality.

Suppression of programmed neuronal death by a thapsigargin-induced Ca2+ influx

Rat sympathetic neurons undergo programmed cell death (PCD) in vitro and in vivo when they are deprived of nerve growth factor (NGF). Chronic depolarization of these neurons in cell culture with elevated concentrations of extracellular potassium ([K+]o) prevents this death. The effect of prolonged depolarization on neuronal survival is thought to be mediated by a rise of intracellular calcium concentration ([Ca2+]i) caused by Ca2+ influx through voltage-gated channels. In this report we investigate the effects of chronic treatment of rat sympathetic neurons with thapsigargin, an inhibitor of intracellular Ca2+ sequestration. In medium containing a normal concentration of extracellular Ca2+ ([Ca2+]o), thapsigargin caused a sustained rise of intracellular Ca2+ concentration and partially blocked death of NGF-deprived cells. Elevating [Ca2+]o in the presence of thapsigargin further increased [Ca2+]i, suggesting that the sustained rise of [Ca2+]i was caused by a thapsigargin-induced Ca2+ influx. This treatment potentiated the effect of thapsigargin on survival. The dihydropyridine Ca2+ channel antagonist, nifedipine, blocked both a sustained elevation of [Ca2+]i and enhanced survival caused by depolarization with elevated [K+]o, suggesting that these effects are mediated by Ca2+ influx through L-type channels. Nifedipine did not block the sustained rise of [Ca2+]i or enhanced survival caused by thapsigargin treatment, indicating that these effects were not mediated by influx of Ca2+ through L-type channels. These results provide additional evidence that increased [Ca2+]i can suppress neuronal PCD and identify a novel method for chronically raising neuronal [Ca2+]i for investigation of this and other Ca(2+)-dependent phenomena.

Chronic depolarization prevents programmed death of sympathetic neurons in vitro but does not support growth: requirement for Ca2+ influx but not Trk activation

Continuous exposure of many types of neurons in cell culture to elevated concentrations of K+ greatly enhances their survival. This effect has been reported to be mediated by a sustained rise of cytoplasmic free Ca2+ concentration caused by influx of Ca2+ through voltage-gated channels activated by K(+)-induced chronic depolarization. In this report we investigate the effects of elevated K+ on the programmed death that embryonic rat sympathetic neurons undergo in culture when deprived of NGF. Elevated K+ in the culture medium did not significantly prevent death of NGF-deprived cells until after the third day following plating of embryonic day 21 neurons. On the fifth day after plating, incrementally increasing K+ concentrations in the culture medium from 5 to 100 mM caused chronic depolarization of neurons and had a biphasic effect on survival of NGF-deprived cells. Enhanced survival was steeply related to membrane potential, increasing from no enhanced survival in cells held at potentials between -51 and -34 mV to 90-100% of control survival at about -21 mV. At potentials positive to -21 mV, survival decreased. Associated with the chronic depolarization was a sustained rise of steady-state free Ca2+ concentration that showed a biphasic relationship to membrane potential roughly similar to that exhibited by survival. Steady-state Ca2+ concentration increased with increasingly lower membrane potentials to a peak at about -23 mV (to approximately 240 nM from approximately 40 nM at about -51 mV) and then decreased at more positive potentials. The elevation of intracellular Ca2+ was largely blocked by dihydropyridine and phenylalkylamine Ca2+ channel antagonists and was potentiated by a dihydropyridine Ca2+ channel agonist. Neither the rise of Ca2+, or survival was affected by the Ca2+ channel antagonist, omega-conotoxin. Therefore, the Ca2+ elevation was probably caused by Ca2+ influx through L-type, but not N-type, channels. Antagonists of L channels blocked both survival and the sustained increase of steady-state free Ca2+ at similar concentrations, suggesting that the relevant factor determining survival of depolarized cells was Ca2+ influx rather than some other effect of depolarization. Surprisingly, however, there was no clear correlation between the sustained rise of Ca2+ and survival. Some membrane potentials that induced similar increases of Ca2+ concentration produced widely different levels of survival. While chronic depolarization promoted survival of neurons in the absence of NGF, cells supported in this manner showed little growth as measured by neurite extension, total cellular protein, and mean somal diameter.(ABSTRACT TRUNCATED AT 400 WORDS)

Physicochemical properties and cytopathogenicity of an adenovirus-like agent isolated from corn snake (Elaphe guttata)

A virus isolated from the internal organs of a moribund corn snake (Elaphe guttata) replicated in reptilian cell cultures (IgH-2, TH-1 cells) between 10 and 30 degrees C. Highest infectivity titers of 10(5.5) TCID50/ml were obtained in IgH-2 cells at 25 degrees C. Infected IgH-2 cells showed the development of three morphologically different intranuclear inclusion bodies. During viral assembly the particles formed typical crystalline aggregates in the nucleus. About 64 h after infection progressive desintegration of the nuclear membrane was evident and virus particles were released into the cytoplasm. Different fish cell lines (CLC, CHSE-214, BF-2, PG, RTG-2) were not capable of propagating the virus. The DNA containing agent proved to be stable at pH3, more or less at pH 12 and to treatment with chloroform, but it was rapidly inactivated at 56 degrees C. Electron microscopy revealed nonenveloped icosahedral particles with a diameter of 65-70 nm.

Evaluation of biological activities of new LH-RH antagonists (T-series) in male and female rats

A series of new highly potent LH-RH antagonists (T-series) has been synthesized in our laboratory. Among these analogs, antagonists [Ac-D-Nal(2), D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Car)2)6, D-Ala10]LH-RH (T-140); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Ac)2)6, D-Ala10]LH-RH (T-148); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(For)2)6, D-Ala10]LH-RH (T-151) and [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2bu(For)2)6, D-Ala10]LH-RH (T-159) were the most powerful. Antagonists T-140, T-148 and T-151 produced a complete blockade of ovulation in normal cycling rats at a dose of 1.5 micrograms/rat and antagonist T-159 at a dose of only 0.75 micrograms/rat. The inhibitory effects of compounds T-148, T-151 and T-159 on gonadotropin and sex steroid secretion were investigated in male and female rats. To determine their effect on LH levels in castrated male and ovariectomized female rats, T-148, T-151 and T-159 were injected subcutaneously in doses of 0.625 and 2.5 micrograms/rat. Blood samples were taken at different intervals for 48 h. All three compounds at either dose caused a significant (P < 0.01) decrease in LH levels for more than 6 h. Significant (P < 0.01) inhibition of LH lasted for more than 24 h following a dose of 2.5 micrograms sc of all 3 antagonists in both male and female rats. Serum FSH levels were also suppressed significantly for more than 48 h in castrated male rats by all three antagonists at a dose of 5 micrograms/rat sc.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of luteinizing hormone-releasing hormone analogs containing cytotoxic radicals on growth of estrogen-independent MXT mouse mammary carcinoma in vivo

Cytotoxic luteinizing hormone-releasing hormone (LH-RH) analogs, AJ-004 (agonist [D-Lys6]LH-RH linked to methotrexate (MTX)), T-98 ([D-Lys6]LH-RH coupled to glutaryl-2-(hydroxymethyl)anthraquinone) (G-HMAQ) and T-121/B (antagonist containing two residues of G-HMAQ) were tested in female BDF1 mice bearing MXT ((3.2)/Ovex) estrogen-independent mammary tumors. All three cytotoxic LH-RH analogs, administered from Alzet Osmotic Minipumps for 3 weeks, produced a significant inhibition of tumor growth. The effects of T-98 and T-121/B were superior to those obtained by treatment with equimolar doses of cytotoxic moiety anthraquinone or the LH-RH carrier alone. We assume that cytotoxic LH-RH analogs have a combined hormonal and cytotoxic activity with a reduced toxicity after administration in vivo. This is the first demonstration of in vivo tumor inhibition by targeted LH-RH analogs bearing cytotoxic radicals.

Antitumor effects of analogs of LH-RH and somatostatin: experimental and clinical studies

Many clinical approaches for the treatment of hormone-sensitive tumors are being developed based on analogs of LH-RH and somatostatin. Inhibition of the pituitary-gonadal axis forms the basis for oncological applications of LH-RH agonists like [D-Trp6]-LH-RH and new LH-RH antagonists free of edematogenic effects such as [Ac-D-Nal(2)1-D-Phe(4Cl)2-D-Pal(3)3,D-Cit6,D-Ala10]-LH -RH (SB-75). Agonists and antagonists of LH-RH have been used in patients with prostate cancer and might be also beneficial for the treatment of breast cancer and ovarian, endometrial and pancreatic carcinomas. Some of the effects of LH-RH analogs can be due to direct action since LH-RH receptors have been found in these cancers. The use of sustained delivery systems based on microcapsules of PLG, makes the treatment more efficacious. Octapeptide analogs of somatostatin such as D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) and related analogs were designed specifically for antitumor activity. These somatostatin analogs, by virtue of having a wide spectrum of activities appear to inhibit various tumors through multiple mechanisms. Direct antiproliferative actions of somatostatin analogs appear to be mediated by specific receptors located on tumor cells. High affinity binding sites for RC-160 and related analogs have been found in human pancreatic, prostate, breast and ovarian cancers and brain tumors such as meningiomas. In vivo administration of analog RC-160 inhibits the growth of Dunning R-3327 prostate cancers in rats, MXT mammary tumors in mice and BOP-induced ductal pancreatic cancers in hamsters. Combination of microcapsules of RC-160 with [D-Trp6]-LH-RH results in synergistic potentiation of the inhibition of these cancers. Somatostatin analog RC-160 and LH-RH antagonist SB-75 are the object of further experimental studies and clinical trials aimed at the exploration of their inhibitory effects on the processes of malignant growth.

Treatment of cardiac myocytes with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate, forskolin or cholera toxin does not stimulate cellular or heparin-releasable lipoprotein lipase activities

Incubation of isolated cardiac myocytes with 500 microM-8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate (CPT-cAMP) or 100 microM-forskolin for 2 1/2 h did not increase the heparin-induced release of lipoprotein lipase (LPL) into the medium. When LPL activity in cardiac myocytes was depleted by treatment of rats with cycloheximide (2 mg/kg; 2.5 h) and inclusion of the protein-synthesis inhibitor in the isolation solutions, incubation with CPT-cAMP or forskolin did not influence the rate of repletion of LPL activity in cells or the recovery of heparin-releasable LPL activity. Although the administration of cholera toxin (0.5 mg/kg; 16-17 h) to rats increased LPL activity in a low-speed supernatant fraction from heparin-perfused hearts, LPL activity was not increased in cardiac myocytes from cholera-toxin-treated rat hearts, and the heparin-induced release of LPL was unchanged. Incubation of cultured ventricular myocytes with 1 microgram of cholera toxin/ml or 500 microM-CPT-cAMP for 24 h did not increase cellular LPL activity or LPL released into the culture medium after a 40 min incubation with heparin. Therefore interventions that stimulate adenylate cyclase activity (forskolin, cholera toxin) or incubation with CPT-cAMP do not increase cellular LPL activity or promote the translocation of LPL to a heparin-releasable fraction in cardiac myocytes.

Highly active and selective anticoagulants: D-Phe-Pro-Arg-H, a free tripeptide aldehyde prone to spontaneous inactivation, and its stable N-methyl derivative, D-MePhe-Pro-Arg-H

D-Phe-Pro-Arg-H sulfate (GYKI-14166) is a highly active and selective inhibitor of thrombin both in vitro and in vivo. Recent studies on the stability of D-Phe-Pro-Arg-H in neutral aqueous solution at higher temperature have revealed that it is transformed into inactive 5,6,8,9,10,10a-hexahydro-2-(3'- guanidinopropyl)-5-benzyl-6-oxo- imidazo[1,2-a]pyrrolo[2,1-c]pyrazine. No such inactivation could be observed with Boc-D-Phe-Pro-Arg-H (GYKI-14451), but this compound was far less specific than the free peptide as it inhibited thrombin and, for instance, plasmin equally well. Assuming that the transformation of free tripeptide aldehyde, mentioned above, can only be initiated by a primary amino terminus, the N-alkyl derivatives of D-Phe-Pro-Arg-H were prepared. Of the new analogues, D-MePhe-Pro-Arg-H (GYKI-14766) proved to be as highly active and selective anticoagulant as its parent compound and was not inactivated by transformation into a heterocyclic compound.

Preferential vulnerability of dendrites to lithium ion in rat brain and in nerve cell culture

Preferential swelling and vacuolation of dendrites were observed electron microscopically in different brain regions of rats treated with LiCl in a dose of 6-18 mmol/kg for 1-6 days. The most severe fine structural changes were revealed in the hippocampus. Low-dose (0.33 mmol/kg) lithium treatment lasting for a year did not cause any morphologically detectable alterations in the rat brain. In vitro studies showed a reduction of dendro-axonal process network of neurons measured by morphometric means after lithium exposure. Using different cultures of neuronal and glial cell populations, higher lithium uptake was observed for neuron-enriched cultures.

The influence of external sodium and potassium on lithium uptake by primary brain cell cultures at "therapeutic" lithium concentration

The ionic regulating of lithium homeostasis and steady-state intra:extracellular lithium distribution in the brain can be approached by experimental methods using intact nerve cells in vitro. Primary cultures prepared from chick embryonic brain were applied to study the effect of extracellular sodium and potassium on the lithium uptake of nerve cells at 'therapeutic' lithium concentration (1.5 mM). Lithium influx and the level of steady-state intracellular lithium were significantly reduced by increasing the external sodium concentration. At physiological extracellular sodium level, the steady-state content of lithium in the brain cells was about half of that observed in the presence of 10 mM sodium in the incubation media and the value of the intra:extracellular lithium distribution ratio was below 1. External potassium (0.5 - 3mM) strongly inhibited lithium uptake of the nerve cells. Ouabain (10(-4)M) had no effect on this potassium-sensitive lithium uptake in Tyrode media. Sodium influx studied by isotope tracer methodology was higher in cultures preloaded with lithium as compared to that of the controls. It can be concluded that sodium and potassium ions, at physiological concentrations, significantly influence lithium uptake as well as the intra:extracellular lithium distribution in brain cell cultures.

The secondary antibody response in tissue culture. II. Differences in the course of antibody synthesis to diphtheria toxoid and rat serum albumin

Lymph node fragments taken from rabbits previously immunized by a single footpad injection of both rat serum albumin and diphtheria toxoid were exposed to a secondary stimulus with either of these two antigens in vitro. The resulting secondary response was followed in tissue culture for a month. A difference was established in the antibody responses to rat albumin and diphtheria toxoid. Anti-diphtheria antibody formation was found to be more sensitive to hydrocortisone and less dependent on the presence of serum in the medium.

The secondary antibody response in tissue culture. I. Observations on prolonged antibody synthesis by lymph node fragments in media of different composition

Lymph node fragments obtained from rabbits immunized 4–9 months previously were cultured in Eagle's medium supplemented with normal rabbit serum or with serine. Upon secondary stimulation with the specific antigen (rat albumin) in vitro, antibody production which lasted over 4 weeks was observed. A difference in the course of antibody synthesis was established in the two different media. In the presence of normal rabbit serum, peak titers of antibody were reached 7–13 days after secondary stimulation, while, in the presence of serine, highest titers were observed on days 13–19. Furthermore, antibody titers diminished faster in the normal rabbit serum cultures as compared to those in the serine cultures. If hydrocortisone was added to culture media containing serine, antibody production by the lymph node fragments followed a pattern similar to that for cultures containing normal rabbit serum. The possible significance of these findings is discussed.

STUDIES ON ANTIBODY FORMATION: I. RELATIONSHIP BETWEEN NUCLEIC ACIDS AND ANTIBODY SYNTHESIS IN THE PRIMARY RESPONSE IN THE RAT

The nucleic acid and protein contents of the various subcellular fractions of rat spleen homogenates were determined at varying intervals of time following a single intravenous injection of sheep red blood cell membranes. Small differences were recorded in the NA content of the different fractions, as compared with controls. The microsomal fraction was the only one to exhibit significant increases in NA content. The protein content of the various subcellular fractions did not show significant deviations from control values. Antibodies could be eluted from microsomes of spleens of immunized rats by sodium deoxycholate and ribonuclease treatment. A quantitative difference was found in the immune response of the two strains of rats used (R.V.H. and Wistar rats).

STUDIES ON ANTIBODY FORMATION: I. RELATIONSHIP BETWEEN NUCLEIC ACIDS AND ANTIBODY SYNTHESIS IN THE PRIMARY RESPONSE IN THE RAT

The nucleic acid and protein contents of the various subcellular fractions of rat spleen homogenates were determined at varying intervals of time following a single intravenous injection of sheep red blood cell membranes. Small differences were recorded in the NA content of the different fractions, as compared with controls. The microsomal fraction was the only one to exhibit significant increases in NA content. The protein content of the various subcellular fractions did not show significant deviations from control values. Antibodies could be eluted from microsomes of spleens of immunized rats by sodium deoxycholate and ribonuclease treatment. A quantitative difference was found in the immune response of the two strains of rats used (R.V.H. and Wistar rats).