A hundred-year-old mystery-the reproductive mode and larval morphology of the enigmatic frog genus Allophryne (Amphibia; Anura; Allophrynidae)

Frogs of the Allophrynidae are an enigmatic family from South America. To date, published information is lacking regarding this group's reproductive biology and larval morphology. Here, we provide the first detailed description of the reproductive mode, developmental mode, and tadpole morphology for Allophryne ruthveni. We developed a captive breeding and rearing protocol for this species and then conducted a series of observations to describe aspects of its reproductive biology. In captivity, this species exhibits aquatic oviposition, where single eggs are laid ungrouped within a simple jelly capsule and are scattered free in the water column before sinking to develop on benthic substrates. We did not observe parental care nor any parental interactions with eggs post-fertilization. Tadpoles are characterized by an oval body, anteroventral oral disc, a labial tooth row formula of 2(2)/3, and a dextral vent tube. The buccopharyngeal cavity is marked by the presence of two pairs of infralabial papilla and four lingual papillae. Cranial morphology is characterized by the presence of the commissura quadratoorbital. This species possesses an additional slip of the m. rectus cervicis and of the m. levator arcuum branchialium III. We discuss our results in comparison with glassfrogs (Centrolenidae).

Vascularization inside the epidermis of Neotropical anurans (Nobleobatrachia)

Anuran skin is a dynamic organ involved in essential functions that strongly correlate with specific morphological traits. Particularly, gas exchange has been associated with epidermal modifications, such as reduced cell layers and increased vascularization. Here, we describe the epidermal morphology and its association with capillary networks in the dorsal skin of 103 Neotropical anurans (Nobleobatrachia) from different ecomorphs and habitats. Additionally, we examined the lateral and ventral skin for a subset of these species. We report intraepidermal capillaries in (i) dorsal skin of Lepidobatrachus laevis and Lepidobatrachus llanensis (burrowing and semi-aquatic Chacoan species), Hyloscirtus colymba and Hyloscirtus palmeri (arboreal species from humid forests), and Alsodes neuquensis and 15 Telmatobius spp. (aquatic and semi-aquatic species from cold environments); (ii) lateral skin of Boana benitezi and H. colymba (arboreal species from humid forests), and (iii) ventral skin of B. benitezi, H. colymba, Atelognathus patagonicus (aquatic species from cold environments), and four Chacoan species, Chacophrys pierottii, Ceratophrys cranwelli (burrowing/terrestrial species), and Lepidobatrachus asper and L. llanensis (burrowing/semi-aquatic species). Also, verrucae hydrophilicae were observed exclusively in the ventral skin of Leptodactylus fuscus, Leptodactylus laticeps (terrestrial and Chacoan species), and B. benitezi. Regardless of the skin region, the capillaries always penetrate the epidermis from the dermis, while epidermal cell layers are flattened. Our findings support previous hypotheses stating that the environment where species occur influences skin changes related to cutaneous respiration (intraepidermal capillaries in different body regions) and water absorption (intraepidermal capillaries associated with verrucae hydrophilicae within ventral skin). Also, phylogeny might influence the development of these structures, as revealed by the presence of intraepidermal capillaries in almost all analyzed species of Telmatobius. Finally, the co-occurrence of verrucae hydrophilicae in the ventral skin of hylids from humid forests, and leptodactylids from the subhumid Chacoan region suggest an independent origin.

Deep-tissue SWIR imaging using rationally designed small red-shifted near-infrared fluorescent protein

Applying rational design, we developed 17 kDa cyanobacteriochrome-based near-infrared (NIR-I) fluorescent protein, miRFP718nano. miRFP718nano efficiently binds endogenous biliverdin chromophore and brightly fluoresces in mammalian cells and tissues. miRFP718nano has maximal emission at 718 nm and an emission tail in the short-wave infrared (SWIR) region, allowing deep-penetrating off-peak fluorescence imaging in vivo. The miRFP718nano structure reveals the molecular basis of its red shift. We demonstrate superiority of miRFP718nano-enabled SWIR imaging over NIR-I imaging of microbes in the mouse digestive tract, mammalian cells injected into the mouse mammary gland and NF-kB activity in a mouse model of liver inflammation.

Glassfrogs conceal blood in their liver to maintain transparency

Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cells (RBCs) that strongly attenuate light. Here, we document how glassfrogs overcome this challenge by concealing these cells from view. Using photoacoustic imaging to track RBCs in vivo, we show that resting glassfrogs increase transparency two- to threefold by removing ~89% of their RBCs from circulation and packing them within their liver. Vertebrate transparency thus requires both see-through tissues and active mechanisms that "clear" respiratory pigments from these tissues. Furthermore, glassfrogs' ability to regulate the location, density, and packing of RBCs without clotting offers insight in metabolic, hemodynamic, and blood-clot research.

High-Frequency 3D Photoacoustic Computed Tomography Using an Optical Microring Resonator

3D photoacoustic computed tomography (3D-PACT) has made great advances in volumetric imaging of biological tissues, with high spatial-temporal resolutions and large penetration depth. The development of 3D-PACT requires high-performance acoustic sensors with a small size, large detection bandwidth, and high sensitivity. In this work, we present a new high-frequency 3D-PACT system that uses a micro-ring resonator (MRR) as the acoustic sensor. The MRR sensor has a size of 80 μm in diameter, and was fabricated using the nanoimprint lithography technology. Using the MRR sensor, we have developed a transmission-mode 3D-PACT system that has achieved a detection bandwidth of ~23 MHz, an imaging depth of ~8 mm, a lateral resolution of 114 μm, and an axial resolution of 57 μm. We have demonstrated the 3D PACT's performance on in vitro phantoms, ex vivo mouse brain, and in vivo mouse ear and tadpole. The MRR-based 3D-PACT system can be a promising tool for structural, functional, and molecular imaging of biological tissues at depths.

Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin

Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations-a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In this study, we show that the occurrence of high biliverdin in anurans (frogs and toads) has evolved multiple times during their evolutionary history, and relies on the same mechanism-the presence of a class of serpin family proteins that bind biliverdin. Using a diverse combination of techniques, we purified these serpins from several species of nonmodel treefrogs and developed a pipeline that allowed us to assemble their complete amino acid and nucleotide sequences. The described proteins, hereafter named biliverdin-binding serpins (BBS), have absorption spectra that mimic those of phytochromes and bacteriophytochromes. Our models showed that physiological concentration of BBSs fine-tune the color of the animals, providing the physiological basis for crypsis in green foliage even under near-infrared light. Additionally, we found that these BBSs are most similar to human glycoprotein alpha-1-antitrypsin, but with a remarkable functional diversification. Our results present molecular and functional evidence of recurrent evolution of chlorosis, describe a biliverdin-binding protein in vertebrates, and introduce a function for a member of the serpin superfamily, the largest and most ubiquitous group of protease inhibitors.

Novel morphological structures in frogs: vocal sac diversity and evolution in Microhylidae (Amphibia: Anura)

Vocal sacs are present in most species of frogs and are the product of the interaction of three elements: the gular skin, the superficial submandibular musculature and an internal mucosa derived from the buccal floor. In this paper, we surveyed the structural diversity in the vocal sac of microhylids and related families in 109 exemplar species, including 11 of the 13 currently recognized subfamilies. We defined five characters related to anatomical and histological properties of the m. interhyoideus, as well as the relationship of this muscle and the vocal sac internal mucosa. We describe a vocal sac configuration characterized by highly abundant elastic fibres in association with muscle fibres, a very unusual structure in animal tissues. We discuss the evolution of novel structures in a phylogenetic context and identify new synapomorphies for Microhylidae and internal clades. Furthermore, we comment on the functional implications that these features have in vocal sac inflation.

An integrative omics perspective for the analysis of chemical signals in ecological interactions

All living organisms emit, detect, and respond to chemical stimuli, thus creating an almost limitless number of interactions by means of chemical signals.

Structural diversity of nuptial pads in Phyllomedusinae (Amphibia: Anura: Hylidae)

We studied the morphological variation of the nuptial pads using light microscopy and scanning electron microscopy (SEM) in 26 species of phyllomedusines (Anura: Hylidae), representing the five currently recognized genera. All phyllomedusines have single nuptial pads with dark colored epidermal projections (EPs). Spine-shaped EPs occur in Cruziohyla calcarifer, Phrynomedusa appendiculata and in one species of Phasmahyla. The other species have roundish EPs. The density of the EPs on the pad is variable. Species in the Phyllomedusa hypochondrialis Group have EPs with a density that varies between 764 ± 58/mm(2) and 923 ± 160/mm(2). In all other studied species (including the Phyllomedusa burmeisteri and Phyllomedusa perinesos groups, Phyllomedusa camba, Phyllomedusa boliviana, Phyllomedusa sauvagii, Phyllomedusa bicolor, and Phyllomedusa tomopterna) the density of EPs varies between 108 ± 20/mm(2) and 552 ± 97/mm(2). Pores were observed with SEM in C. calcarifer, Agalychnis lemur, Agalychnis moreletii, but its presence is confirmed through histological sections on several other species. Its visibility using SEM seems to be related with the level of separation between adjacent EPs. The pores in the four studied species of Agalychnis are shown with SEM and histological sections to have a characteristic epidermal rim, that is absent in the otherphyllomedusines. Unlike most previous reports on breeding glands, those of phyllomedusines are alcian blue positive, indicating the presence of acidic mucosubstances on its secretions.

Immunological evaluation of bacterial derived Cochleate and proteoliposome as mucosal adjuvants

We evaluated the potential of two bacterial derived compounds, Cochleate and Proteoliposome (PL), administrated to mice by nasal or oral routes on induction of antibody and cytokine responses. Anti PL IgG and IgA responses were measured by ELISA in saliva, sera or vaginal fluids of immunized mice. Productions of gammaIFN and IL-5 were determined in spleen cells of immunized mice following a recall in vitro with Cochleate or PL. Intranasal administration elicited a higher anti PL IgA response in both saliva and vaginal fluids as compared with oral route. Mice immunized with Cochleate or PL via intranasal or oral route-induced anti PL IgG and IgG2a antibody responses in their sera and vaginal fluids. Spleen cells from these immunized mice produced gammaIFN, but not IL-5, after a recall in vitro with Cochleate or PL. These results show that Cochleate and PL are capable of inducing both systemic and mucosal antibody responses as well as a Th1 type of immunity as evidenced by high gammaIFN and IgG2a antibody responses.

Adjuvant properties of lipopolysaccharide from Neisseria meningitidis serogroup B detoxified and conjugated with tetanus toxoid

We evaluated the adjuvant properties and toxicity of purified Neisseria meningitidis serogroup B lipopolysaccharide (LPS) conjugated with tetanus toxoid (TT) using a new method of conjugation to obtain amine groups in the polysaccharide structure. The endotoxic activity of treated LPS was reduced 2400 times as determined by Limulus amoebocyte assay and no mortality was observed in Balb/c mice inoculated with detoxified LPS versus 100% mortality in native LPS inoculated mice. The conjugated LPS-TT elicited in mice higher anti-TT IgG2a and IgG1 than unconjugated TT. In addition, high levels of anti-LPS IgG and IgG subclasses were detected in sera. These results evidence the adjuvant activity of detoxified LPS and may suggest that the conjugation to TT changes the LPS immune response from thymus-independent to thymus-dependent.

Proteliposome-derived Cochleate as an immunomodulator for nasal vaccine

Proteoliposome (PL) has been recently used as a protective intramuscular (i.m.) anti-meningococcal BC vaccine. It induces a preferential Th 1 type of immune response. Nevertheless, mucosal protection is mainly mediated by IgA antibody response, which is not usually induced by i.m. vaccination route. IgA antibody production needs the stimulation of Th3 subpopulation, which is also related to the induction of small dose tolerance. We hypothesized that PL-derived Cochleate can induce a specific mucosal IgA and systemic IgG antibody responses. We could show that mice immunized with two or three intranasal doses of PL-derived Cochleate developed significantly increased levels of local anti PL IgA and systemic IgG antibody responses. Thus, our results suggest that PL-derived Cochleate can be used as a promising immunomodulator and delivery system for the development of mucosal, particularly nasal vaccines.

Proteoliposome derived cochleate as novel adjuvant

Cochleate structures (CS) consist in a highly stable lipid structures that have been reported to be a good antigen delivery system. The incorporation of pathogen associated molecular pattern (PAMP) from bacterial membranes into CS became in a promising approach to develop adjuvants, particularly mucosal adjuvants. Therefore, we prepare CS from proteoliposome (PL) obtained from Neisseria meningitidis B (PLCS) and evaluated it for its capability to stimulate the immune system as well as the adjuvant activity. The ability of PLCS to induce Thl polarization was also explored. The results and the easy capability for new antigen incorporation on CS support its use as adjuvant for immunization with a large variety of pathogen derived antigens and different routes of immunization.

Scale up of proteoliposome derived Cochleate production

Cochleate are highly stable structures with promising immunological features. Cochleate structures are usually obtaining from commercial lipids. Proteoliposome derived Cochleate are derived from an outer membrane vesicles of Neisseria meningitidis B. Previously, we obtained Cochleates using dialysis procedures. In order to increase the production process, we used a crossflow system (CFS) that allows easy scale up to obtain large batches in an aseptic environment. The raw material and solutions used in the production process are already approved for human application. This work demonstrates that CFS is very efficient process to obtain Cochleate structures with a yield of more than 80% and the immunogenicity comparable to that obtained by dialysis membrane.

Novel adjuvant based on a proteoliposome‐derived cochleate structure containing native lipopolysaccharide as a pathogen‐associated molecular pattern

Proteoliposomes (PL) from Neisseria meningitidis B have been widely used as a core antigen for antimeningococcal vaccination. PL contain major outer membrane proteins, LPS and phospholipids, and they induce a strong Th1 immune response, but they have low stability in solution. Attending to the need for new vaccine adjuvants, we developed a highly stable cochleate structure (CS) from PL using a technology that allows easy incorporation of new antigens. We explored the ability of PLCS to activate the immune system and its possible application as an adjuvant for parenteral and mucosal routes. Our results showed that PLCS were able to upregulate the expression of MHC class II and costimulatory molecules on human dendritic cells, as well as being able to stimulate the production of soluble mediators of a Th1 response, such as IL-12 and nitric oxide. High levels of anti-PL IgG were detected in serum after i.m. or mucosal (oral and nasal) administration, but also anti-PL secretory IgA was produced in saliva following nasal delivery. The immune response polarization to a Th1 pattern was confirmed by the induction of IgG2a antibodies, positive delayed type hypersensitivity reactions, and IFN-gamma production by splenocytes from immunized mice. The adjuvant potential was explored using PLCS containing ovalbumin (Ova). PLCS-Ova was able to elicit a substantial increase in anti-Ova IgG compared with Ova alone. In addition, a significant reduction in lesion size was observed in mice immunized with Leishmania major antigens in PLCS after challenge with virulent protozoa, suggesting at least partial modulation of the Th2 environment induced by this parasite. In conclusion, our results support the use of PLCS as a potent Th1 adjuvant for parenteral and mucosal vaccines.

Effects of dietary L-arginine supplementation on serum lipids and intestinal enzyme activities in diabetic rats

We investigated whether dietary supplementation with L-arginine, the endogenous precursor of nitric oxide, might affect serum lipid levels and activities of intestinal mucosa enzymes in animals, in which diabetes was induced by administration of streptozotocin. Control and diabetic rats were fed diets with or without 2% L-arginine supplementation for 4 weeks. Diabetic rats had significantly higher concentrations of serum triglycerides and LDL-cholesterol than control rats. These alterations were partially reduced by L-arginine supplementation. Experimental diabetes did not influence the lactase and leucine aminopeptidase activity in the intestine, but the activity of alkaline phosphatase was increased. Furthermore, activities of maltase and sucrase in the intestinal mucosa were elevated in streptozotocin-induced diabetic rats and were restored to control levels after dietary L-arginine supplementation. On the basis of the present experimental evidence, dietary L-arginine supplementation appears to affect the metabolism of lipoproteins and might alleviate some gastrointestinal dysfunctions, commonly seen in diabetes mellitus.

An economic model of haemophilia in Mexico

A model was developed to assess the lifetime costs and outcomes associated with haemophilia in Mexico. A retrospective chart review of 182 type A haemophiliacs was conducted for patients aged 0-34 years receiving one of three treatments: (i) cryoprecipitate at clinic; (ii) concentrate at home; or (iii) concentrate at clinic. Patients treated at home experienced 30% less joint damage, used 13-54% less factor VIII, had four times fewer clinic visits, and utilized half as many hospital days than those treated at a clinic. For cryoprecipitate at clinic patients, the annual incidence rates of HCV and HIV were calculated to be 3.6% and 1.4% respectively. The life expectancy for patients receiving cryoprecipitate and those receiving concentrate was estimated to be 49 years and 69 years respectively, with 58% of cryoprecipitate patients predicted to die of AIDS before age 69. Across the lifespan, the average annual cost of care was US$11,677 (MN$110,464) for cryoprecipitate at clinic patients, US$10,104 (M$95,580) for concentrate at home patients and US$18,819 (MN$178,027) for concentrate at clinic patients. Using a 5% discount rate, the incremental lifetime cost per year of life added for treatment with concentrate at home compared with cryoprecipitate at a clinic was US$738 (MN$6981). Rank order stability analysis demonstrated that the model was most sensitive to the cost of fVIII. These results indicate that treatment with concentrate at home compared with cryoprecipitate at a clinic substantially improves clinical outcomes at reduced annual cost levels.

Standardization of Neisseria meningitidis serogroup B colorimetric serum bactericidal assay

The correlate of protection for serogroup B meningococci is not currently known, but for serogroup C it is believed to be the serum bactericidal assay (SBA). The current SBAs are labor intensive and the variations in protocols among different laboratories make interpretation of results difficult. A colorimetric SBA (cSBA), based on the ability of Neisseria meningitidis serogroup B to consume glucose, leading to acid production, was standardized by using group B strain Cu385-83 as the target. The cSBA results were compared to those obtained for a traditional colony-counting microassay (mSBA). Glucose and bromocresol purple pH indicator were added to the medium in order to estimate growth of cSBA target cell survivors through color change. Different variants of the assay parameters were optimized: growth of target cells (Mueller Hinton agar plates), target cell number (100 CFU/per well), and human complement source used at a final concentration of 25%. After the optimization, three other group B strains (H44/76, 490/91, and 511/91) were used as targets for the cSBA. The selection of the assay parameters and the standardization of cSBA were done with 13 sera from vaccinated volunteers. The titers were determined as the higher serum dilution that totally inhibited the bacterial growth marked by the color invariability of the pH indicator. This was detected visually as well as spectrophotometrically and was closely related to a significant difference in the growth of target cell survivors determined using Student's t test. Intralaboratory reproducibility was +/-1 dilution. The correlation between bactericidal median titers and specific immunoglobulin G serum concentration by enzyme immunoassay was high (r = 0.910, P < 0.01). The bactericidal titers generated by the cSBA and the mSBA were nearly identical, and there was a high correlation between the two assays (r = 0.974, P < 0.01). The standardized cSBA allows easy, fast, and efficient evaluation of samples.

Nutritional value of the marine invertebrates Anemonia viridis and Haliothis tuberculata and effects on serum cholesterol concentration in ratsopen star

The purpose of this study was to determine the nutritional value of diets with protein from two marine species (Haliotis tuberculata and Anemonia viridis) as compared to a high-quality protein reference based on casein or casein supplemented with olive oil. We also investigated the effects of these diets on serum lipid levels. Male rats were fed these diets for 23 days. Protein quality indicators (true digestibility, net protein utilization, biological value) were similar to those obtained for casein-based feeds except for lower true digestibility and net protein utilization values for the Anemonia viridis feed. HDL-cholesterol level was significantly higher (p < 0.05) in the groups fed marine species or casein supplemented with olive oil than in the casein group. Total-cholesterol level was higher in the group fed Haliotis tuberculata fed than in the other groups. These results suggest that these marine species are a good protein source, and that they may have positive effects on serum cholesterol level.

Colon-specific delivery of budesonide from microencapsulated cellulosic cores: evaluation of the efficacy against colonic inflammation in rats

Budesonide (BDS) is a potent corticosteroid that has important implications in the pharmacotherapy of inflammatory bowel disease, especially in the treatment of ulcerative colitis and Crohn's disease. BDS is available on the market in the form of enteric-coated preparations. However these products, similar to other available site-specific dosage forms, are not sufficiently selective to treat colonic inflammatory bowel disease. The objective of this study was to evaluate the efficacy of a new microparticulate system containing BDS, to treat experimentally induced colitis in rats. This microparticulate system consisted of BDS-containing hydrophobic cores, microencapsulated within an enteric polymer, which solubilizes at above pH 7, thus combining pH-sensitive and controlled-release properties. Colonic injury and inflammation were assessed by measuring colon/bodyweight ratio, myeloperoxidase (MPO) activity, and by scoring macroscopic and histological damage in colitic rats. Rats were treated orally with BDS, included in the developed system, once a day for 4 days after the induction of inflammation. A BDS suspension and BDS-containing enteric microparticles were included as control formulations in the experimental design. The administration of the new BDS delivery system significantly reduced the colon/bodyweight ratio compared with the administration of control formulations. Similarly, MPO activity and macroscopic and histological damage of the inflamed colonic segments decreased significantly when the BDS formulation was administered, compared with the results obtained after oral administration of the drug suspension. There were no significant differences, however, when the new treatment was compared with the control formulation consisting of simple enteric microparticles.

Immune response induction and new effector mechanisms possibly involved in protection conferred by the Cuban anti-meningococcal BC vaccine

This report explores the participation of some afferent mechanisms in the immune response induced by the Cuban anti-meningococcal vaccine VA-MENGOC-BC. The induction of delayed-type hypersensitivity in nursing babies and lymphocyte proliferation after immunization is demonstrated. The presence of gamma interferon IFN-gamma and interleukin-2 (IL-2) mRNAs but absence of IL-4, IL-5, and IL-10 mRNAs were observed in peripheral blood mononuclear cells from immunized subjects after in vitro challenge with outer membrane vesicles. In addition, some effector functions were also explored. The presence of opsonic activity was demonstrated in sera from vaccinees. The role of neutrophils as essential effector cells was shown. In conclusion, we have shown that, at least in the Cuban adult population, VA-MENGOC-BC induces mechanisms with a T-helper 1 pattern in the afferent and effector branches of the immune response.

Nutritive value of protein from sea urchin, and its effects on intestinal leucine aminopeptidase and intestinal and hepatic gamma-glutamyltranspeptidase

Seafoods are a rich source of easily digestible protein that also provides polyunsaturated fatty acids, vitamins and minerals for human nutrition. The purpose of this study was to determine the nutritive value of diets high in protein from two species of sea urchin (Paracentrotus lividus and Echinus esculentus) as compared to a high-quality reference protein such as casein, as well as the effects of these diets on leucine aminopeptidase and gamma-glutamyltranspeptidase, intestinal and hepatic enzymes. The test was carried out on three groups of male rats fed these diets for 23 days. The result of the nutritive parameters indicated that sea urchin, Echinus esculentus, were significantly lower than the casein protein except for food intake, and the nutritive parameters of sea urchin, Paracentrotus lividus, were similar to the values obtained for casein protein except for digestibility and net protein utilization. Intestinal leucine aminopeptidase activity was significantly lower (P < 0.05) in the group fed Paracentrotus lividus as compared to the group fed casein. Intestinal gamma-glutamyltranspeptidase showed a significantly higher activity in the group fed E. esculentus than in the two other groups and the hepatic gamma-glutamyltranspeptidase activity in the groups fed the two species of sea urchin were lower. Nutritive values suggested that these marine species are a good protein source and similar to casein. The activity of the enzymes under study must have been affected by the amino acid composition of the protein.

Dietary effects of marine food intake on intestinal and hepatic enzyme activities in rats

Dietary effects of two diets high in protein from two marine species (Haliotis tuberculata and Anemonia viridis) as compared to a high-quality patron protein such as casein (or casein supplemented with olive oil) on intestinal and hepatic enzymes were studied. After 23 days, the two marine species as diet compared to casein increased the disaccharidase and alkaline phosphatase activities. Feeding Haliotis tuberculata meal produced a decrease on intestinal leucine aminopeptidase activity. The hepatic gamma-glutamyltranspeptidase activity decreased slightly in animals fed Haliotis tuberculata meal. Supplementation of casein with olive oil tended to decrease the intestinal and hepatic enzyme activity.

Development of tablets for controlled joint release of nifedipine and atenolol

Oral combinations of nifedipine and atenolol are widely used in the treatment of hypertension, proving particularly effective when the atenolol is released immediately and the nifedipine is released in a sustained manner. This work examined the potential of combining nifedipine and atenolol in a tablet, which would be easier to manufacture than currently available combined formulations. The results indicated that a 40:60 (w/w) nifedipine-atenolol mixture forms a eutectic melting at 140 degrees C. Nevertheless, both drugs were stable when incorporated in tablets elaborated using cellulose ethers as base excipients. Tablets prepared from atenolol-lactose granules and solid dispersions of nifedipine-hydroxypropylmethylcellulose (100 cP) had more adequate dissolution profiles than a more complex reference formulation in hard capsules.

Metabolic effects in rats of verapamil alone and in combination with captopril

The metabolic effects of verapamil alone and in combination with captopril were investigated in rats. Animals received the maximum recommended doses for humans (per kg body weight per day) over a 2-week period. Verapamil had no significant effects on serum biochemistry, but caused a significant increase in serum potassium level and significant reductions in the rates of intestinal absorption of glucose and calcium. Verapamil/captopril had a number of significant effects on serum lipid profile (increased total cholesterol, increased HDL-cholesterol, and reduced LDL-cholesterol), and also provoked an increase in serum alanine amino-transferase activity and in serum glucose levels. The combination treatment caused a significant increase in serum chloride levels, but had no effect on intestinal absorption.

Nifedipine/atenolol interactions in gastrointestinal absorption and biotransformation

The combination of nifedipine and atenolol is widely used for the treatment of hypertension. In the present study, experiments performed in rats indicated that neither drug affects the gastric or intestinal absorption of the other. In assays of the biotransformation of nifedipine in liver homogenates, breakdown was much more rapid in homogenates from male rats than from female rats. In the presence of atenolol, the breakdown rate was significantly increased in homogenates from male rats, and significantly reduced in homogenates from female rats.

Metabolic effects of the combination of furosemide and captopril in rat

Diuretics typically provoke increased serum lipid levels and may provoke increased serum uric acid levels and/or glucose intolerance. Furosemide is widely used as an antihypertensive, but in patients for whom furosemide treatment alone proves insufficient to reduce hypertension, a common procedure is to co-administer the angiotensin-converting-enzyme (ACE) inhibitor captopril. The metabolic effects in rats of joint administration of furosemide (15 mg/kg/day) and captopril (2 mg/kg/day) are evaluated over a two-week period. At the end of this period, the serum levels of lipids, uric acid, bilirubin, proteins and various enzymes were determined as well as the effect of the treatment on intestinal absorption of glucose and calcium. Furosemide/captopril led to an increase in serum albumin and alkaline phosphatase levels, and a decrease in triglyceride levels. The results of this work support the view that this drug combination is suitable for hypertension treatment.

Low doses of high-potency antithymocyte globulin (ATG) in severe aplastic anemia: experience with the Mexican ATG

Twenty patients with severe aplastic anemia (SAA) were treated with low doses (1-5 mg/kg/day) of a high-potency antithymocyte globulin (ATG) produced in Mexico, shown to have at least a 10-fold potency as compared with other globulins of commercial sources. Patients received ATG within a 10-day period, every other day (5 doses) at a dose of 1 mg/kg/day (4 courses), 2 mg/kg/day (12 courses) or 5 mg/kg/day (8 courses). Four patients received 2 consecutive courses of different doses of ATG. A response rate of 42% was recorded in the group, assessed by means of increases in reticulocytes, granulocytes or platelets. One patient showed a complete remission. The 570-day survival of the group was 51%. It is concluded that the domestically produced ATG is useful in the treatment of some patients with SAA in Mexico.

Effects of fish meal as source of protein on intestinal maltase activity and intestinal and renal leucine aminopeptidase activity of growing rats

The effect of high-protein fish meal on maltase and leucine aminopeptidase (LAPase) activities of the intestinal mucosa as well as the renal LAPase activity was studied. Four groups of female Wistar rats, weighing between 40-60 g, were fed diets with a 4 or 12% protein content of dry matter for 25 days. The protein source was casein for the control groups and fish meal derived from Coryphaenoides rupestris for the test groups. The results show a decrease (p less than 0.005) in intestinal maltase and LAPase activities and renal LAPase activity in animals fed with 12% of fish meal protein compared to those fed with casein, while the rats fed 4% of fish meal protein showed a decrease in intestinal maltase activity and no significant difference in LAPase activity compared with the control group. These results seem to indicate that the intestinal maltase is influenced by the quality and quantity of dietary protein, while the intestinal and renal LAPase activity is only changed by the quality of protein.

Effect of somatostatin on small intestine enzyme activities in rat and chick

The influence of somatostatin injection on intestinal disaccharidase and alkaline phosphatase activity in rat and chick was investigated. Disaccharidase and alkaline phosphatase activities of rat and chick homogenates were not modified. In rat the activities of mucosal brush-border maltase and sucrase were significantly increased. In chick brush-border a significant increase of duodenal mucosal activity and duodenal and jejunal sucrase activity is observed.

Somatostatin and 3-oxy-methyl-D-glucose (3-OMG) uptake in isolated chicken intestinal epithelial cells

The direct effect of somatostatin on the absorption of 3-oxymethylglucose in epithelial cells isolated from the small intestine of chicken was studied. The presence of somatostatin in the incubation medium at concentrations of 3.5 X 10(-8) M and 7 X 10(-8) M produced significant dose-dependent increases in the accumulation of sugar in the enterocytes. This effect might be due to an increase in the cell membrane permeability caused by hormone action.