Leptin and obesity

An imbalance between calorie intake and energy expenditure produces obesity. It has been a major problem in societies of the developing and developed world. In obesity an excessive amount of fat accumulates in adipose tissue cells as well as in other vital organs like liver, muscles, and pancreas. The adipocytes contain ob genes and express leptin, a 16 kDa protein. In the present communication, we reviewed the molecular basis of the etiopathophysiology of leptin in obesity. Special emphasis has been given to the use of leptin as a drug target for obesity treatment, the role of diet in the modulation of leptin secretion, and reduction of obesity at diminished level of blood leptin induced by physical exercise.

Effect Of Transtibial Prosthesis Mass On Gait Asymmetries

BACKGROUND

Individuals with transtibial amputation (TTA) typically walk with an asymmetrical gait pattern, which may predispose them to secondary complications and increase risk of fall. Gait asymmetry may be influenced by prosthesis mass.

OBJECTIVES

To explore the effects of prosthesis mass on temporal and limb loading asymmetry in people with TTA following seven days of acclimation and community use.

METHODOLOGY

Eight individuals with transtibial amputation participated. A counterbalanced repeated measures study, involving three sessions (each one week apart) was conducted, during which three load conditions were examined: no load, light load and heavy load. The light load and heavy load conditions were achieved by adding 30% and 50% of the mass difference between legs, at a proximal location on the prosthesis. Kinematic and ground reaction force data was captured while walking one week after the added mass. Symmetry indices between the prosthetic and intact side were computed for temporal (Stance and Swing time) and limb loading measures (vertical ground reaction force Peak and Impulse).

FINDINGS

Following seven days of acclimation, no significant differences were observed between the three mass conditions (no load, light load and heavy load) for temporal (Stance time: p=0.61; Swing time: p=0.13) and limb loading asymmetry (vertical ground reaction force Peak: p=0.95; vertical ground reaction force Impulse: p=0.55).

CONCLUSIONS

Prosthesis mass increase at a proximal location did not increase temporal and limb loading asymmetry during walking in individuals with TTA. Hence, mass increase subsequent to replacing proximally located prosthesis components may not increase gait asymmetry, thereby allowing more flexibility to the clinician for component selection.

Occurrence, management and outcome of immune-complex glomerulonephritis in dogs with suspected glomerulopathy in the UK

OBJECTIVES

To determine the proportion of dogs diagnosed with immune-complex glomerulonephritis in a large cohort of UK dogs with clinical suspicion of glomerular disease in which renal histopathology, including routine light microscopy, transmission electron microscopy and immunofluorescence, had been performed. The second objective was to describe treatment and long-term clinical outcome of dogs diagnosed with immune-complex glomerulonephritis.

MATERIALS AND METHODS

Sixty-two UK dogs that underwent renal biopsies for investigation of suspected glomerulopathy (urine protein-to-creatinine ratio persistently >0.5) were included in this retrospective multicentre study. Signalment, clinico-pathological abnormalities, histopathological diagnosis, treatment following diagnosis and survival were recorded.

RESULTS

Seventeen (27%) of the dogs with suspected glomerular disease were diagnosed with immune-complex glomerulonephritis and nine (53%) of these were still alive at the study end point, with a median follow-up of 366 days (range 52 to 1299). Six dogs diagnosed with immune-complex glomerulonephritis were treated with mycophenolate. Four received mycophenolate alone for immunosuppression and two received mycophenolate and chlorambucil; all these six dogs were alive at data collection [median follow-up time 712.5 days (range 73 to 1299)]. Seven dogs diagnosed with immune-complex glomerulonephritis did not receive immunosuppressive treatment; only one of these dogs was alive at study end point [median survival time 302 days (range 52 to 723)].

CLINICAL SIGNIFICANCE

Immune-complex glomerulonephritis may be less common in the UK than previously reported in North America and mainland Europe, reducing the likelihood of treatment modification following renal biopsy. Mycophenolate was the most commonly used immunosuppressant for cases of immune-complex glomerulonephritis.

Association between ultrasonographic appearance of urine and urinalysis in dogs and cats

OBJECTIVE

To evaluate association between ultrasonographic urine echogenicity and sediment examination in dogs and cats.

MATERIALS AND METHODS

Dogs and cats undergoing ultrasound-guided cystocentesis at a multidisciplinary referral hospital. Ultrasonographic images were stored and reviewed by a single, blinded, board-certified radiologist. Urine appearance was described as "echoic" or "anechoic". Urine sediment was examined for bacteriuria, pyuria, haematuria, crystalluria and urine-specific gravity and then classified as "active" or "inactive."

RESULTS

Of the 194 cases included in this study, urine was echoic in 52 and anechoic in 142. Sediment was active in 52 and inactive in 142 samples. Sensitivity and specificity of echoic urine for active sediment were 40% (95% CI: 27 to 55%) and 78% (95% CI: 70 to 85%), respectively. Positive predictive value and negative predictive value of echoic urine for active sediment were 40% (CI 30 to 52%) and 78% (CI 74 to 82%), respectively. If urine-specific gravity was <1.015 urine was always described ultrasonographically as anechoic.

CLINICAL SIGNIFICANCE

Association between sediment analysis and ultrasonographic appearance of urine is poor. Echoic urine had low positive predictive value for active sediment in this study, suggesting that echoic urine alone should not prompt urinary investigations in the absence of other clinical suspicion. Despite a negative predictive value of 78%, urinalysis is still indicated for anechoic urine, especially if urine specific gravity is low.

ZNFX-1 Functions within Perinuclear Nuage to Balance Epigenetic Signals

Animal cells have a remarkable capacity to adopt durable and heritable gene expression programs or epigenetic states that define the physical properties and diversity of somatic cell types. The maintenance of epigenetic programs depends on poorly understood pathways that prevent gain or loss of inherited signals. In the germline, epigenetic factors are enriched in liquid-like perinuclear condensates called nuage. Here, we identify the deeply conserved helicase-domain protein, ZNFX-1, as an epigenetic regulator and component of nuage that interacts with Argonaute systems to balance epigenetic inheritance. Our findings suggest that ZNFX-1 promotes the 3' recruitment of machinery that propagates the small RNA epigenetic signal and thus counteracts a tendency for Argonaute targeting to shift 5' along the mRNA. These functional insights support the idea that recently identified subdomains of nuage, including ZNFX-1 granules or "Z-granules," may define spatial and temporal zones of molecular activity during epigenetic regulation.

The Coding Regions of Germline mRNAs Confer Sensitivity to Argonaute Regulation in C. elegans

Protein-coding genes undergo a wide array of regulatory interactions with factors that engage non-coding regions. Open reading frames (ORFs), in contrast, are thought to be constrained by coding function, precluding a major role in gene regulation. Here, we explore Piwi-interacting (pi)RNA-mediated transgene silencing in C. elegans and show that marked differences in the sensitivity to piRNA silencing map to the endogenous sequences within transgene ORFs. Artificially increasing piRNA targeting within the ORF of a resistant transgene can lead to a partial yet stable reduction in expression, revealing that piRNAs not only silence but can also “tune” gene expression. Our findings support a model that involves a temporal element to mRNA regulation by germline Argonautes, likely prior to translation, and suggest that piRNAs afford incremental control of germline mRNA expression by targeting the body of the mRNA, including the coding region.

A Sex Chromosome piRNA Promotes Robust Dosage Compensation and Sex Determination in C. elegans

In metazoans, Piwi-related Argonaute proteins engage piRNAs (Piwi-interacting small RNAs) to defend the genome against invasive nucleic acids, such as transposable elements. Yet many organisms-including worms and humans-express thousands of piRNAs that do not target transposons, suggesting that piRNA function extends beyond genome defense. Here, we show that the X chromosome-derived piRNA 21ux-1 downregulates XOL-1 (XO Lethal), a master regulator of X chromosome dosage compensation and sex determination in Caenorhabditis elegans. Mutations in 21ux-1 and several Piwi-pathway components sensitize hermaphrodites to dosage compensation and sex determination defects. We show that the piRNA pathway also targets xol-1 in C. briggsae, a nematode species related to C. elegans. Our findings reveal physiologically important piRNA-mRNA interactions, raising the possibility that piRNAs function broadly to ensure robust gene expression and germline development.

Clinical leishmaniasis in dogs living in the UK

OBJECTIVES

To investigate the prevalence of leishmaniasis in dogs in the UK and to describe clinical presentation, clinicopathological abnormalities, therapeutic protocols and outcome in this non-endemic country.

MATERIALS AND METHODS

Medical records of dogs diagnosed with leishmaniasis at seven referral centres in the UK were retrospectively reviewed.

RESULTS

The prevalence was between 0·007 and 0·04% with a higher number of cases in southern England. All dogs had a history of travel to or from an endemic country. Lethargy, dermatological disease, decreased appetite and lameness were the most common reasons for presentation. Allopurinol was used alone for treatment in the majority of cases.

CLINICAL SIGNIFICANCE

Although rare, leishmaniasis should be considered in dogs in the UK if they have compatible clinical signs and history of travel to or from endemic areas.

Unusual Grignard Reaction of α-Arylcinnamonitriles [1]

Reaction of α-arylcinnamonitriles with excess of alkylmagnesium halide yielded predominantly the erythro isomer of α,β-dialkyl-α,β-diarylpropionitriles. PMR spectra of the diastereoisomers have been described.

The Vasa Homolog RDE-12 engages target mRNA and multiple argonaute proteins to promote RNAi in C. elegans

Argonaute (AGO) proteins are key nuclease effectors of RNAi. Although purified AGOs can mediate a single round of target RNA cleavage in vitro, accessory factors are required for small interfering RNA (siRNA) loading and to achieve multiple-target turnover. To identify AGO cofactors, we immunoprecipitated the C. elegans AGO WAGO-1, which engages amplified small RNAs during RNAi. These studies identified a robust association between WAGO-1 and a conserved Vasa ATPase-related protein RDE-12. rde-12 mutants are deficient in RNAi, including viral suppression, and fail to produce amplified secondary siRNAs and certain endogenous siRNAs (endo-siRNAs). RDE-12 colocalizes with WAGO-1 in germline P granules and in cytoplasmic and perinuclear foci in somatic cells. These findings and our genetic studies suggest that RDE-12 is first recruited to target mRNA by upstream AGOs (RDE-1 and ERGO-1), where it promotes small RNA amplification and/or WAGO-1 loading. Downstream of these events, RDE-12 forms an RNase-resistant (target mRNA-independent) complex with WAGO-1 and may thus have additional functions in target mRNA surveillance and silencing.

The C. elegans CSR-1 argonaute pathway counteracts epigenetic silencing to promote germline gene expression

Organisms can develop adaptive sequence-specific immunity by reexpressing pathogen-specific small RNAs that guide gene silencing. For example, the C. elegans PIWI-Argonaute/piwi-interacting RNA (piRNA) pathway recruits RNA-dependent RNA polymerase (RdRP) to foreign sequences to amplify a transgenerational small-RNA-induced epigenetic silencing signal (termed RNAe). Here, we provide evidence that, in addition to an adaptive memory of silenced sequences, C. elegans can also develop an opposing adaptive memory of expressed/self-mRNAs. We refer to this mechanism, which can prevent or reverse RNAe, as RNA-induced epigenetic gene activation (RNAa). We show that CSR-1, which engages RdRP-amplified small RNAs complementary to germline-expressed mRNAs, is required for RNAa. We show that a transgene with RNAa activity also exhibits accumulation of cognate CSR-1 small RNAs. Our findings suggest that C. elegans adaptively acquires and maintains a transgenerational CSR-1 memory that recognizes and protects self-mRNAs, allowing piRNAs to recognize foreign sequences innately, without the need for prior exposure

piRNAs initiate an epigenetic memory of nonself RNA in the C. elegans germline

Organisms employ a fascinating array of strategies to silence invasive nucleic acids such as transposons and viruses. Although evidence exists for several pathways that detect foreign sequences, including pathways that sense copy number, unpaired DNA, or aberrant RNA (e.g., dsRNA), in many cases, the mechanisms used to distinguish "self" from "nonself" nucleic acids remain mysterious. Here, we describe an RNA-induced epigenetic silencing pathway that permanently silences single-copy transgenes. We show that the Piwi Argonaute PRG-1 and its genomically encoded piRNA cofactors initiate permanent silencing, and maintenance depends on chromatin factors and the WAGO Argonaute pathway. Our findings support a model in which PRG-1 scans for foreign sequences and two other Argonaute pathways serve as epigenetic memories of "self" and "nonself" RNAs. These findings suggest how organisms can utilize RNAi-related mechanisms to detect foreign sequences not by any molecular signature, but by comparing the foreign sequence to a memory of previous gene expression.

Epoxyeicosanoids stimulate multiorgan metastasis and tumor dormancy escape in mice

Epoxyeicosatrienoic acids (EETs) are small molecules produced by cytochrome P450 epoxygenases. They are lipid mediators that act as autocrine or paracrine factors to regulate inflammation and vascular tone. As a result, drugs that raise EET levels are in clinical trials for the treatment of hypertension and many other diseases. However, despite their pleiotropic effects on cells, little is known about the role of these epoxyeicosanoids in cancer. Here, using genetic and pharmacological manipulation of endogenous EET levels, we demonstrate that EETs are critical for primary tumor growth and metastasis in a variety of mouse models of cancer. Remarkably, we found that EETs stimulated extensive multiorgan metastasis and escape from tumor dormancy in several tumor models. This systemic metastasis was not caused by excessive primary tumor growth but depended on endothelium-derived EETs at the site of metastasis. Administration of synthetic EETs recapitulated these results, while EET antagonists suppressed tumor growth and metastasis, demonstrating in vivo that pharmacological modulation of EETs can affect cancer growth. Furthermore, inhibitors of soluble epoxide hydrolase (sEH), the enzyme that metabolizes EETs, elevated endogenous EET levels and promoted primary tumor growth and metastasis. Thus, our data indicate a central role for EETs in tumorigenesis, offering a mechanistic link between lipid signaling and cancer and emphasizing the critical importance of considering possible effects of EET-modulating drugs on cancer.

White blood cell count and the sodium to potassium ratio to screen for hypoadrenocorticism in dogs

BACKGROUND

Abnormal sodium to potassium (Na:K) ratios can raise suspicion for hypoadrenocorticism (HA). Although dogs with HA usually have normal leukograms, their white blood cell counts may be useful in screening for HA.

OBJECTIVES

To examine the utility of combining the Na:K ratio with white blood cell counts to screen for HA in hospitalized dogs requiring fluid treatment administered i.v..

ANIMALS

Fifty-three dogs with confirmed HA and 110 sick dogs confirmed not to have HA.

METHODS

Retrospective, case-control study. Dogs were included if they were hospitalized and administered fluids i.v., had a complete blood count and measurement of serum Na and K concentrations. HA was diagnosed using an ACTH stimulation test, or ruled out by measurement of basal serum cortisol concentration.

RESULTS

The receiver operating characteristic (ROC) curve for the lymphocyte count was not significantly different from the ROC curve of the Na:K ratio (P = .55). The ROC curve for the model combining the Na:K ratio and lymphocyte count was superior for identifying dogs with HA compared to the Na:K ratio (P = .02) or lymphocyte count (P = .005) alone. At the 100% sensitivity cutoff, lymphocyte count was more specific for detection of HA than Na:K (P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

A combination of the Na:K ratio and lymphocyte count provides a better screening test for HA compared to the Na:K ratio or lymphocyte count alone. At 100% sensitivity, the lymphocyte count is a more specific test for HA than the Na:K.

Biomarker discovery in subclinical mycobacterial infections of cattle

BACKGROUND

Bovine tuberculosis is a highly prevalent infectious disease of cattle worldwide; however, infection in the United States is limited to 0.01% of dairy herds. Thus detection of bovine TB is confounded by high background infection with M. avium subsp. paratuberculosis. The present study addresses variations in the circulating peptidome based on the pathogenesis of two biologically similar mycobacterial diseases of cattle.

METHODOLOGY/PRINCIPAL FINDINGS

We hypothesized that serum proteomes of animals in response to either M. bovis or M. paratuberculosis infection will display several commonalities and differences. Sera prospectively collected from animals experimentally infected with either M. bovis or M. paratuberculosis were analyzed using high-resolution proteomics approaches. iTRAQ, a liquid chromatography and tandem mass spectrometry approach, was used to simultaneously identify and quantify peptides from multiple infections and contemporaneous uninfected control groups. Four comparisons were performed: 1) M. bovis infection versus uninfected controls, 2) M. bovis versus M. paratuberculosis infection, 3) early, and 4) advanced M. paratuberculosis infection versus uninfected controls. One hundred and ten differentially elevated proteins (P < or = 0.05) were identified. Vitamin D binding protein precursor (DBP), alpha-1 acid glycoprotein, alpha-1B glycoprotein, fetuin, and serine proteinase inhibitor were identified in both infections. Transthyretin, retinol binding proteins, and cathelicidin were identified exclusively in M. paratuberculosis infection, while the serum levels of alpha-1-microglobulin/bikunin precursor (AMBP) protein, alpha-1 acid glycoprotein, fetuin, and alpha-1B glycoprotein were elevated exclusively in M. bovis infected animals.

CONCLUSIONS/SIGNIFICANCE

The discovery of these biomarkers has significant impact on the elucidation of pathogenesis of two mycobacterial diseases at the cellular and the molecular level and can be applied in the development of mycobacterium-specific diagnostic tools for the monitoring progression of disease, response to therapy, and/or vaccine based interventions.

Sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) gene silencing and remodeling of the Ca2+ signaling mechanism in cardiac myocytes

Transient elevations of cytosolic Ca2+ are a common mechanism of cellular signaling. In striated muscle, the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) plays an important role in terminating Ca2+ transients by returning cytosolic Ca2+ to intracellular stores. Stored Ca2+ can then be released again for subsequent signaling. We down-regulated SERCA2 gene expression in cultured cardiac myocytes by means of endogenous transcription of small interfering RNA encoded by an exogenous cDNA template. The cDNA template was delivered by adenovirus vector. Reduction of SERCA expression in all myocytes in culture was documented by immunochemistry, real-time RT-PCR, and determination of ATP-dependent Ca2+ transport. The reduction of SERCA2 expression was associated with the up-regulation of transient receptor potential (TRP) channel proteins (TRPC4 and TRPC5) and Na+/Ca2+ exchanger, indicating that intracellular store deficiency was compensated for by Ca2+ fluxes through the plasma membrane. In fact, SERCA silencing was followed by increased transcription of Na+/Ca2+ exchanger, TRPC4, TRPC5, and related transcriptional factors, such as stimulating protein 1, myocyte enhancer factor 2, and nuclear factor of activated cells 4, through activation of calcineurin. This finding demonstrates that the observed compensation occurs through transcriptional crosstalk and the remodeling of Ca2+ signaling pathways. The wide significance of this regulatory mechanism is related to its general involvement in Ca2+ signaling dynamics and in cardiac development and hypertrophy.

MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis

Secondary intradural arachnoid cyst involving the spine is uncommon. It is usually secondary to trauma, haemorrhage, surgery or inflammation. We present two cases of treated tuberculous meningitis, which presented with gradual onset of quadriplegia and paraplegia, respectively. MRI revealed intradural (cervical and thoracic) arachnoid cysts (ventral and dorsal to the spinal cord) with myelomalacic cord changes. Ventral location of such spinal arachnoid cysts, and being secondary to tuberculous arachnoiditis are distinctively uncommon features. The rarity of this condition and the relevance of MRI in the accurate diagnosis have been discussed here.

Dependence of relativistic effects on electronic configuration in the neutral atoms of d- and f-block elements

Although most neutral d- and f-block atoms have nd(g-2)(n + 1)s(2) and (n - 1)f(g-2)(n + 1)s(2) ground configurations, respectively, where g is the group number (i.e., number of valence electrons), one-third of these 63 atoms prefer a higher d-population, namely via (n + 1)s-->nd "outer" to "inner" electron shift (particularly atoms from the second d-row), or via (n - 1)f-->nd "inner" to "outer" electron shift (particularly atoms from the second f-row). Although the response to the modified self-consistent field is orbital destabilization and expansion for (n + 1)s-->nd, and stabilization and contraction for (n - 1)f-->nd, the relativistic modification of the valence orbital responses is stabilization in both cases. This is explained by double perturbation theory. Accordingly, electron configuration and relativity trigger the orbital energies, the orbital populations and the chemical shell effects in different ways. The particularly pronounced relativistic effects in groups 10 and 11, the so-called gold maximum, occur because of particularly efficient cooperative nonrelativistic shell effects and relativistic stabilization effects (inverse indirect effect) at the end of the d-block.

Syntheses and anthelmintic activity of alkyl 5(6)-(substituted carbamoyl)- and 5(6)-(disubstituted carbamoyl)benzimidazole-2-carbamates and related compounds

A number of alkyl 5(6)-(substituted-carbamoyl)- and 5(6)-(disubstituted-carbamoyl)benzimidazole-2-carbamates and related compounds have been synthesized, and their anthelmintic activity against various intestinal helminths of experimental animals have been evaluated. A large percentage of the compounds synthesized showed noteworthy activity against Ancylostoma ceylanicum and at higher doses against Hymenolepsis nana infections. Compared to the alkyl 5(6)-(substituted-carbamoyl)benzimidazole-2-carbamates, the disubstituted carbamoyl analogues were found to exhibit better anthelmintic activity. The most active compound of the series, namely, methyl 5(6)-[(N-2-pyridylpiperazino)carbamoyl]benzimidazole-2-carbamate (90), has been screened against intestinal helminths in higher animals and as a micro- and macrofilaricidal agent. Compound 90 has been identified as a broad-spectrum anthelmintic agent. Compound 90 has been identified as a broad-spectrum anthelmintic in view of its efficacy against A. ceylanicum (hamsters and dogs), H. nana (rats), Nippostrongylus brasiliensis (rats), Syphacia obvelata (mice), A. tubaeformis (cat), Toxocara spp. (cat), and Litomosoides carinii (cotton rat).

Dimers of Podocarpic Acid Derivatives

Treatment of methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (5) with a commercial sample of thallium(III) trifluoroacetate gave a low yield (5%) of a non-symmetric ether-linked dimer (15). Use of freshly prepared thallium(III) trifluoroacetate gave a 28% yield of the symmetrical biaryl dimer (16). The dimethyl ether (17) was prepared in low yield (10%) by treatment of methyl 12-methoxypodocarpa-8,11,13-trien-19-oate (4) with the latter reagent.

Multi-input optical parallel logic processing with the shadow-casting technique

The lensless shadow-casting technique for coded pattern processing usually accommodates two inputs at a time to perform desired logical operations in parallel. A method of binary encoding is proposed that can accommodate multiple input patterns for simultaneous processing. With the proposed multiple-input encoding a carry-look-ahead technique of binary addition is developed that requires fewer processing steps than the conventional ripple-carry method. Experimental results for a few logic-processing operations are included to establish the validity of the proposed technique.

Topical atropine and timolol therapy in failed retinal detachment surgery

We conducted a double-blind randomized prospective study to evaluate the efficacy of topical timolol alone and topical timolol and atropine combined in cases of operated failed retinal detachment surgery cases in which no apparent open break explained the surgical failure. In both groups with and without proliferative vitreoretinopathy no statistically significant difference in retinal reattachment was found.

Reversal of chloroquine resistance in Plasmodium falciparum by CDR 87/209 and analogues

The spreading of resistance towards chloroquine has diminished its value as a potent and safe drug in malaria endemic areas. Recent reports on the reversal of chloroquine resistance in the malaria parasite Plasmodium falciparum in vitro and in vivo by verapamil, desipramine and other Ca(2+)-channel blockers and antidepressants has initiated a strategy for chemotherapy by treatment with chloroquine in combination with a drug resistance modulator. Described here is a class of modulators of distinct structure which reverse chloroquine resistance in a different manner. Contrary to verapamil and desipramine, CDRI 87/209, the most potent compound of this new class and used as a chemical lead, did not restore chloroquine accumulation in the resistant parasites, thereby indicating that besides the proposed blockade of drug efflux other mechanisms are vulnerable targets for a chemotherapeutic approach towards drug resistance. Similar to the former modulators, CDRI 87/209 showed only weak intrinsic plasmodicidal activity and the increase of drug susceptibility was restricted to resistant plasmodia.

Effect of five-membered heterocycles against Leishmania donovani infection

Impact of change of heteroatom in pentavalent heterocycles, viz., pyrroles, isoxazoles, imidazoles and crotonates on the profile of antileishmanial activity against amastigotes of L. donovani using in vivo test system and macrophage-amastigote culture system has been studied. Sixty-three compounds were tested. Nine imidazoles showed marginal activity in vivo, whereas 3 out of 10 compounds of isoxazolone series and 2 out of 4 substituted aminocrotonates exhibited antileishmanial activity. Of the 30 substituted pyrroles, except 8 all showed antileishmanial activity in vivo on day 7 post treatment.

Pregnancy interceptive efficacy and biological profile of 3-amino-6,7-dimethoxy-1H-pyrazolo [3,4-b] quinoline (compound 85/83) in rodents

Administration of compound 85/83 during the peri- and post-implantation period intercepted pregnancy in hamster and guinea pig by parenteral route and in hamster by oral route also. The m.e.d. for hamster and guinea pig was 10 and 20 mg/kg, respectively; lower doses were less effective. Restricting the administration to early post-implantation schedule interrupted pregnancy partially in both species. The compound was, however, ineffective in rat and in the pre-implantation schedule (days 1-4 post-coitum) in hamster. When tested in vitro on growing trophoblasts at 13.8 x 10(-5) M concentration, it prevented growth and caused degeneration of the cells within 24 h; lower concentration (9.2 x 10(-5) M) was less effective. The compound was found to be devoid of estrogenic, antiestrogenic, progestational and antiprogestational properties in conventional bioassays. In hormone competition assays, its relative binding affinity (RBA) to estrogen receptor was negligible (0.002% of estradiol-17 beta), while for uterine cytosol progesterone receptors in rabbit and hamster was 0.06 and 0.08% of progesterone, respectively. The compound 85/83 appears to intercept pregnancy by interfering with development of trophoblast cells.

Regioselective reactions of 1,2-dehydroprogesterone: syntheses of pregnane derivatives as possible contragestational agents

A few pregnane derivatives were synthesized from 1,2-dehydroprogesterone (1). Ring A of 1,2-dehydroprogesterone was aromatized without affecting C-20, and the resulting acetoxy compound (2) after hydrolysis yielded 1-hydroxy-4-methyl-19-norpregna-1,3,5(10)-trien-20-one (3). Reactions of the phenol (3) with alkyl halides yielded the ethers 6a-6b and 7. Opening of the oxirane ring in 7 with secondary amines furnished the aminoalcohols 8a-8b. Friedelcraft's reaction of 3 with maleic anhydride and chloracetyl chloride led to the formation of 9 and 10, respectively. Base-catalyzed ring closure of 10 yielded 1-acetyl-12a-methyl-8-oxo-5[H]-1,2,3,3a,3b,4,8,9,10b,11,12, 12a-dodecahydrocyclopenta (7,8)-phenanthro (3,4-b) furan (11), which reacted with aromatic aldehydes regioselectively to furnish 12a-12b. Reaction of 1 with triethylorthoformate in the presence of boron trifluoride etherate involved the participation of C-21, and the carbonyl at C-3 remained unaffected. The product 13 was identified as 21-[2-hydroxyvinyl]-21-norpregna-1,4-diene-3,20-dione. Reductive amination with sodium cyanoborohydride in the presence of ammonium acetate did not attack ring A and smoothly furnished the amine 14 which, on reaction with succinic anhydride, gave 20-succinamylpregna-1,4-dien-3-one (15).

Chemotherapy of filariasis--on the search of new agents effective on the reproductive system of female adult worms

The design and synthesis of a series of alkyl 5(6)-substituted benzimidazole-2-carbamates (1-13), 7-chloro-4-(4-substituted phenyl)aminoquinolines (14-16), 1,2-dimethyl-3-methoxy-carbonyl-4,5-disubstituted pyrroles (17-19) and some compounds belonging to the class pimelonitrile (20), dihydroquinoline (21), pyridine (22), pyridoquinoline (23) and tetrahydro-pyrimidine (24) have been carried out as possible antifilarial agents. All these compounds have been evaluated for their activity against male and female adult worms of Litomosoides carinii in cotton rats. The effect of these compounds was also observed on the reproductive system (condition of developing microfilariae and their release from uterus) of adult female worms. In this study, three types of compounds were discovered: (a) those which showed activity on both the male and female adult worms and also had sterilizing effects on surviving adult females (1-3, 6-9, 13, 19), (b) those which only sterilized the adult females (14-16, 21, 24), and (c) those which had no effect on female reproduction but killed only adult worms (4, 5, 11, 12, 17, 18, 20, 22, 23). This tends to open up a new avenue in the chemotherapy of filariasis and the future scope of work on chemosterilization of adult females has been discussed.

Radical curative activity of a new 8-aminoquinoline derivative (CDRI 80/53) against Plasmodium cynomolgi B in monkeys

An analogue of primaquine, N1-(3-acetyl-4-5-dihydro-2-furanyl)-N4-(6-methoxy-8-quinolinyl) 1,4-pentanediamine, CDRI Code 80/53), has been evaluated for anti-relapse activity against sporozoite induced Plasmodium cynomolgi B infection in rhesus monkeys. The compound has shown 100% curative anti-relapse activity at 1.25 mg/kg x 7 day dose schedule, thereby giving a primaquine index of 0.8. The compound is currently under Phase-I clinical trials.

Exploration of antileishmanial activity in heterocycles; results of their in vivo & in vitro bioevaluations

A total of 51 imidazoles, pyrroles, quinolines and isoxazolines compounds were screened for antileishmanial activity in vivo and in vitro, using Leishmania donovani as the test parasite. The screening revealed hitherto unknown antileishmanial activity in these heterocycles. Three of the compounds screened (one belonging to isoxazoline series and two from pyrrole series) showed significant anti-leishmanial activity, ranging from 86-91 per cent inhibition in hamsters. When tested in vitro, using macrophage amastigote culture system, these compounds showed inhibition of 62-78 per cent at 30 micrograms/ml concentration.

Syntheses and bioevaluation of substituted dihydropyridines for pregnancy-interceptive activity in hamsters

A number of 2,6-dimethyl-3,5-bis(methoxycarbonyl)-4-substituted-1,4- dihydropyridines were synthesized and evaluated for pregnancy-interceptive activity in mated hamsters. Out of 24 compounds, 12, 15, 21, 22, 28, and 34 caused a marked reduction in the number of implantations when administered on days 3-8 postcoitum. In an in vitro competition assay, none of the compounds exhibited noticeable binding affinity for uterine progesterone receptors. The results reported here have helped to identify new leads for developing pregnancy-interceptive agents and the active compounds do not seem to elicit their interceptive effect through receptor-mediated inhibition of progesterone action in hamster uterus.

Temporal fluctuations in HIV quasispecies in vivo are not reflected by sequential HIV isolations

A genetic study has been made of the HIV tat gene from sequential HIV-1 isolates and the corresponding infected peripheral blood mononuclear cells. DNA was amplified by polymerase chain reaction (PCR) and cloned into a eukaryotic expression vector. Twenty clones were sequenced from each sample. Comparing the sequential HIV isolates, abrupt differences were seen between the major forms of each isolate. These progressive changes were not reflected at all among the in vitro samples. The fluctuation in the quasispecies in vivo may suggest a much more dynamic role for latently infected mononuclear cells. High frequencies of functionally defective tat genes were identified. Given such complexity and the evident differences between quasispecies in vivo and in vitro, the task of defining HIV infection in molecular terms will be difficult.

Molecular interaction of non-steroidal compounds with uterine progesterone receptor (Part II)

Some possible non-steroidal antiprogestins were evaluated for their receptor binding activity by competitive protein binding assay in rabbit as well as human uterine cytosol in vitro. Of the 42 compounds belonging to 5 different series tested, dimethyl ester of monobenzylidene succinic acid, 4-ethoxycarbonyl-3-(m-methoxybenzyl)-5-(m-anisyl)-gamma-butyrolact one and 2-(3-benzyl-oxybenzyl)-3-(3-acetoxybenzyl)butane-1,4-diol exhibit around 20% inhibition of 3H-progesterone binding to uterine cytosol in both species.

Contraceptive and hormonal properties of a new 1,4-dihydro-2-oxoquinoline derivative (compound 84-182) in rodents and rhesus monkeys

Compound 84-182 prevented pregnancy when administered subcutaneously at 10 mg/kg dose on days 3-8 post-coitum in hamsters and on days 6-10 post-coitum in guinea pigs. At lower doses, while in hamsters there was a marked reduction in implantation number, majority of implantations in guinea pigs showed signs of resorption. The compound was ineffective when administered at 10 mg/kg dose on days 1-3 or 6-7 post-coitum in hamsters and on days 1-5 or 4-8 post-coitum in rats. In rhesus monkeys, treatment with the compound at 5 and 10 mg/kg doses on days 16-21 of the menstrual cycle induced frank vaginal bleeding between days 21 and 24. Treatment on days 21-30 or after confirmation of pregnancy on days 32-36 was ineffective. In conventional bioassays, the compound was devoid of any estrogenic, antiestrogenic, progestational, antiprogestational, androgenic or antiandrogenic properties at the contraceptive dose. In competitive protein binding assay, the compound showed relative binding affinity (RBA) of less than 0.1% and 0.28% of progesterone, respectively, for rabbit and hamster uterine cytosol progesterone receptors. Its RBA for rat uterine cytosol estrogen receptors was less than 0.1% of estradiol-17 beta.

Molecular interaction of nonsteroidal compounds with uterine progesterone receptor (Part I)

Progesterone-receptor binding affinity of some nonsteroidal molecules was assessed by competitive protein binding assay in rabbit as well as human uterine cytosol in vitro. Of 40 compounds belonging to 5 different series tested, 3-(p-anisoyl)-2-chloro-6, 7-dimethoxy-quinoline exhibited around 50% inhibition whereas 2-(p-anisoyl) naphthalene and 3-substituted phenyl-1-(3-(2-chloro-6, 7-dialkoxy) quinolinyl)prop-2-en-1-one showed around 20% inhibition in 3H-progesterone binding for rabbit and human uterine progesterone receptor.

Specific interaction of some non-steroidal compounds with the progesterone binding site of uteroglobin

Uteroglobin binds progesterone with high affinity. A few substituted diphenyl ketones were observed to inhibit uteroglobin-progesterone binding in a dose-dependent manner. 4,4'-Dimethoxy-2-hydroxy benzophenone had relatively higher affinity for uteroglobin. The structure-activity relationship amongst the substituted diphenyl ketones indicated considerable sensitivity towards minor structural modifications. These observations offer a tool to investigate nonsteroidal compounds in relation to progesterone related functions of uteroglobin in pregnancy.

Fertility impairment in females--present status

Various approaches towards the control of fertility in females have been discussed. The salient observations made in the field of reproductive physiology which may generate new leads for the development of agents capable of inhibiting pregnancy, are described. The discussion concerning the oestrogen and progesterone receptors is directed towards designing new antifertility agents. The different areas of fertility control covered in this survey are of importance for basic and applied research.