Nota sobre algunos helmintos para el Perú / Note about some helmintes for Peru

Se da conocer por primera vez en el Perú, la presencia de algunos helmintos. Cestoda: Ophiotaenia calmetti (Barros, 1858) La Rue, 1911. Trematoda: Athesmia heterolecithoides (Braun, 1899) Looss, 1899; Nematoda: Molineus nasuae Lent & Freitas, 1938; Uncinaria stenocephala (Railliet, 1884) Railliet, 1885; Uncinaria sp. y Hastospiculum onchocercum Chiwood, 1932

[Homologies between hemerythrins of sipunculids and cadmium-binding metalloprotein (MP II) from a polychaete annelid, Nereis diversicolor]. / Homologies entre les hémérythrines des sipunculiens et une métalloprotéine complexant le cadmium (MP II) d'une annélide polychète, Nereis diversicolor.

The determination of the first 33 amino acids of the Cd-binding-protein (MP II) of Nereis diversicolor (Annelida, Polychaeta) shows a homology of 79 and 61% with 2 respiratory proteins of sipunculids, respectively the myohemerythrin and the hemerythrin. The positive reaction obtained by immunocytochemistry over the hemerythrocytes of Sipunculus nudus using antibodies raised against MP II and the presence of iron on the MP II reinforce this similarity.

Panagrellus redivivus and Caenorhabditis elegans: evidence for the absence of sialic acids.

Complementary experiments were performed to indicate the presence or absence of sialic acids in axenically cultured Panagrellus redivivus and Caenorhabditis elegans. Competitive displacement experiments with radiolabeled Limax flavus agglutinin demonstrated the presence of sialic acid in nematodes grown in medium which contained liver extract as a growth factor but the absence of sialic acid when heme was substituted for liver extract. This finding suggested that sialic acid present in the liver medium was responsible for conflicting results of other studies. Transmission electron microscopy of thin sections from nematodes labeled with an LFA-ferritin conjugate revealed no label to the surface area of the cephalic chemosensilla. Fluorometric analysis with a modification of the thiobarbituric acid assay was negative for sialic acid. Analyses by gas chromatography-mass spectrometry, sensitive to the high picomole range, were also negative for sialic acid. Taken together the results provide evidence for the absence of sialic acid in P. redivivus and C. elegans using the most sensitive and diagnostic technique currently available.

La gnatostomiasis en México / Gnathostomiasis in Mexico

A partir de 1975 se empezaron a observar,primero en las ciudades de Temazcal,Oaxaca,y Tierra Blanca, Veracruz, y luegoen otras de la cuenca del río Papaloapan, un número creciente de enfermos con edema inflamatoriosmigratorios, fugaces y recidivantes; el número de enfermos se acerca actualmente a los 200. La infección se ha relacionado siempre con la ingestión de pescados cíclidos de la presa Miguel Alemán, y consumidos en forma de ceviche, es decir, no tratados por el calor. La especie implicada, aunque aún no identificada con absoluta seguridad, debe ser muy cercana a Gnathostoma spinigerum. Se describen los cambios ecológicos y sociales que la construcción de la presa produjo y que se piensa puedan estar relacionados con la diseminación del parásito en la región. El Centro Piscicola de Temazcal proporcionó tilapias a muchos criaderos secundarios en diversas partes de la República, lo que hace tener que la infección se propague en una forma generalizada. En este trabajo, se describen minuciosamente las diversas formas de la enfermedad, para que los médicos mexicanos puedan reconocerla si llegara a presentarse

Distribution of zinc in parasitic helminths.

The distribution of zinc in representative groups of parasitic helminths was determined by the use of the atomic absorption spectrophotometer. The results of these analyses have shown that growing flukes (smaller forms) with active oogenesis and spermatogenesis contained more zinc than old (large) or very old adults with an empty uterus and large lobulated testes. In cestodes, the neck region and immature proglottids showed more zinc concentration than mature and gravid proglottids and fully grown cyst walls. Similarly, the youngest endogenous daughter cysts of Echinococcus granulosus contained more zinc in their walls than those of larger/older forms. Zinc was concentrated more in nematode eggs than in adult females.

Studies on the surface coat (glycocalyx) of the dauer larva of Anguina agrostis.

Imprints of the surface coat (glycocalyx) from the cuticles of living second stage dauer larvae (DL2) of Anguina agrostis (syn. A. funesta) have been examined using incident light fluorescence microscopy and scanning electron microscopy. These surface coats contain residues of N-acetyl-D-glucosamine which were detected by treatment with wheat germ agglutinin labelled with either fluorescein or rhodamine. They also contain protein which was demonstrated by treatment with either pepsin or trypsin. These enzymes inhibited the attachment of the coryneform bacterium Clavibacter sp. to the surface coat, indicating that proteins play a crucial role in the adhesion of these bacteria to the nematode. This inhibition of attachment was reversed within 18 h after removal of the DL2 from the enzymes, indicating that the nematode was capable of renewing its surface proteins.

Cytochrome b5 and NADH-cytochrome-b5 reductase from sipunculan erythrocytes; a methemerythrin reduction system from Phascolopsis gouldii.

We report the purification and characterization of a soluble cytochrome b5 from coelomic erythrocytes of the sipunculan worm, Phascolopsis gouldii. We also report the isolation and purification of a membrane-bound NADH-cytochrome-b5 reductase from these erythrocytes. The non-heme iron protein, hemerythrin (Hr), is known to be the oxygen carrier in these erythrocytes. The aforementioned purified cytochrome b5 and reductase together catalyze the reduction of P. gouldii [Fe(III),Fe(III)]metHr to [Fe(II),Fe(II)deoxyHr by NADH. EPR spectroscopy demonstrates that a redox process involving formation of the intermediate [Fe(II),Fe(III)]semi-metHr occurs within intact sipunculan erythrocytes as well as in the system of purified components. The rhombic g-tensor of the EPR signal in both cases resembles that of (semi-met)RHr, the form obtained by one-electron reduction of metHr. These observations suggest that cytochrome b5 and NADH-cytochrome-b5 reductase in sipunculan erythrocytes function to counteract autoxidation of oxyHr. The sequence of electron flow in the system of purified components is: NADH----NADH-cytochrome-b5 reductase----cytochrome b5----metHr. At pH 7.5, the reduction of metHr in this system occurs in two phases, only the first of which is dependent on concentration of cytochrome b5. From an analysis of the kinetics and the EPR time-course, we propose that the two phases represent sequential reduction of met- to semi-metHr and reduction of semi-metHr to deoxyHr. This report represents the first demonstration of a physiological system for reduction of metHr.

The effect of piperazine adipate and parbendazole on the carbohydrate metabolism of Ascaridia galli and Heterakis gallinae.

Carbohydrate metabolism of Ascardia galli and Heterakis gallinae was studied after their exposure in vitro to 10(-2) to 10(-5) M piperazine adipate and parbendazole for 10 to 60 min. Following treatment with 10(-2) M piperazine adipate O2 uptake was reduced by 87% in A. galli and 70% in H. gallinae, while parbendazole (10(-2) M) reduced O2 uptake by 70% and 86%, respectively. Glycogen contents were reduced significantly by 10(-2) M piperazine adipate in both the worms, while lactic acid level was enhanced. Parbendazole, however, did not cause any significant change in glycogen contents and lactic acid level in either parasite.

Immunocytochemical localization of neurosecretory amines and peptides in the free-living nematode, Goodeyus ulmi.

Mammalian antibodies to the neuroamines, serotonin and gamma-amino-butyric acid (GABA) and to the neuropeptides, adrenocorticotrophic hormone (ACTH) and FMRF-amide evoked a response to Goodeyus ulmi, a free-living nematode. Serotonin-like immunoreactivity was found in cell bodies in the nerve ring and in the ventral nerve cord in all developmental stages. Neurons in the vulva, implicated in egg-laying, were immunoreactive to anti-serotonin in G. ulmi females, while in males serotonergic nerve fibres was found in the spicular region. Immunoreactivity to ACTH was also seen to differ depending on the developmental stage of G. ulmi, being present only in the ventral cord from the late L3 stage. Anti-GABA immunoreactivity was localized in two cell bodies near the amphids in all life stages and FMRF-amide immunoreactivity was seen in the nerve ring in all developmental stages. No reactivity was found with antibodies to vasointestinal peptide and somatostatin-14.

Intermediate filaments in muscle and epithelial cells of nematodes.

Current concepts of the developmentally controlled multigene family of intermediate filament (IF) proteins expect the origin of their complexity in evolutionary precursors preceding all vertebrate classes. Among invertebrates, however, firm ultrastructural as well as molecular documentation of IFs is restricted to some giant axons and to epithelia of a few molluscs and annelids. As Ascaris lumbricoides is easily dissected into clean tissues, IF expression in this large nematode was analyzed by electron microscopic and biochemical procedures and a monoclonal antibody reacting with all mammalian IF proteins. We document for the first time the presence of IFs in muscle cells of an invertebrate. They occur in three muscle types (irregular striated pharynx muscle, obliquely striated body muscle, uterus smooth muscle). IFs are also found in the epithelia studied (syncytial epidermis, intestine, ovary, testis). Immunoblots on muscles, pharynx, intestine, uterus, and epidermis identify a pair of polypeptides (with apparent molecular masses of 71 and 63 kD) as IF constituents. In vitro reconstitution of filaments was obtained with the proteins purified from body muscle. In the small nematode Caenorhabditis elegans IF proteins are so far found only in the massive desmosome-anchored tonofilament bundles which traverse a special epithelial cell type, the marginal cells of the pharynx. We speculate that IFs may occur in most but perhaps not all invertebrates and that they may not occur in all cells in large amounts. As electron micrographs of the epidermis of a planarian--a member of the Platyhelminthes--reveal IFs, the evolutionary origin of this cytoplasmic structure can be expected either among the lowest metazoa or already in some unicellular eukaryotes.

Amino acid sequence of the active site of Acanthamoeba myosin II.

We have used the substrate [5,6-3H]UTP for direct photoaffinity labeling of the active site of the heavy chain of myosin II from Acanthamoeba castellanii. The only labeled peptide in a total tryptic digest had the sequence of Thr-Glu-Asn-Thr-Me2Lys-Lys (where Me2Lys represents dimethyllysine) with the substrate covalently bound to the Glu residue. This sequence differs at only one position from the sequence of residues 184-189 of nematode myosin heavy chain (Me2Lys----Lys), a post-translational modification, and at two additional positions from residues 185-190 of rabbit skeletal muscle myosin (Glu----Val and Lys----Arg). The partial sequence of a larger labeled peptide derived from total chymotryptic digestion was compatible with and extended this sequence. A 20-residue sequence that contains the active site, tryptic hexapeptide is otherwise identical in Acanthamoeba and rabbit skeletal muscle myosins and has only one more difference in nematode myosin. Because UTP is a substrate for myosin II and a "zero-length" probe, we believe that it identifies amino acid residues that are very close to the substrate during the catalytic cycle.

A micro-technique for preparing homogenates of biological samples.

A method is described for preparing homogenates of insects, mites, nematodes, or fungal spores for electrophoretic analysis which overcomes the disadvantages of existing methods. It is also applicable to the homogenization of microsamples of animal tissue. The method involves grinding the samples in glass tubes, closed at one end, prepared from melting-point capillaries. A range of plungers is fabricated from the stainless-steel plungers from broken microsyringes, or from stainless-steel wire. The plunger is operated by hand to homogenize a sample in 2-20 microliter of buffer in a tube. The techniques for handling the samples before and after homogenization and for labeling and centrifuging them are described. Compared with existing methods, the procedure minimizes sample loss and risk of cross-contamination and eliminates the possibility of overheating the sample during homogenization.

Naturally crystalline hemoglobin of the nematode Mermis nigrescens. An in situ microspectrophotometric study of chemical properties and dichroism.

A dichroic microspectrophotometer was used to measure isotropic and dichroic absorbance spectra of this unique cytoplasmic hemoglobin and its derivatives. A perfusion slide enabled changing the media bathing the Mermis head. The native spectrum, which has an exceptionally low alpha-band extinction, was shown to be entirely due to oxyhemoglobin. The CO-hemoglobin spectrum is more typical, however, the alpha- and beta-bands are unusually closely spaced. A ferric hemochrome was formed on oxidation with ferricyanide or hydroxylamine and was readily converted to ferric hemoglobin cyanide on adding cyanide. Aquoferric hemoglobin and ferric hemoglobin fluoride were not easily formed. Deoxyhemoglobin, identified by its typical absorption spectrum, was formed only under the extremely low O2 pressures attainable in the presence of dithionite. A glucose oxidase, catalase solution deoxygenated hemoglobin in human erythrocytes but not in adjacent Mermis preparations. The affinity for O2 is much greater than for CO. Also, spectral evidence points to an oxyheme environment that is different than in vertebrate hemoglobin and myoglobin. The polarization ratio (PR) magnitude and the PR spectrum were unaffected by perfusion with high refractive index solvents; therefore, form dichroism due to the rodlike crystals is negligible. Maximum extinction is approximately perpendicular to the long axis of the microscopic crystals, which are oriented parallel to the body axis within the hypodermal cells. The PR spectra of the hemoglobin derivatives strongly resemble the corresponding spectra previously reported of single crystals made of horse hemoglobin, whale myoglobin, or Aplysia myoglobin and change appropriately when the ligand is changed. This confirms that the intracellular crystals of Mermis are of oxyhemoglobin.

Isolation and partial characterization of cuticular collagen from the parasitic nematode Gaigeria pachyscelis.

The cuticle from adult Gaigeria pachyscelis was isolated by solubilizing the internal tissues with sodium dodecyl sulphate (SDS) at 37 degrees C. Cuticular protein was extracted with guanidine-HCl and beta-mercaptoethanol and purified by ammonium sulphate fractionation and DEAE-cellulose chromatography. SDS-polyacrylamide gel electrophoresis of purified protein revealed 2 polypeptides with apparent mol. wts of 58,000 and 74,000. As judged from their hydroxyproline content both of them are collagenous in nature. Results of gel filtration indicate that cuticular collagen exists in two forms, a non-associated form at low concentration and an associated form at high concentration.

Differences in mucus-stimulating serum fractions of cystic fibrosis patients and controls.

In nature, the urn cell complexes which swim in the coelomic fluid of the marine invertebrate, Sipunculus nudus, produce "tails" of mucus in response to bacterial pathogens. Since they produce measurable tails of mucus in vitro, suspensions of urn cell complexes provide a bioassay for mucus-stimulating substances (MSS) in biological fluids, including several human body fluids. Heat-activated seawater dilutions of human serum contain MSS. Serum from 87 cystic fibrosis (CF) homozygotes, 60 obligate heterozygotes, and 45 controls were fractionated on a Sephadex G-200 gel filtration column. After subsequent heating for 4 min at 85 degrees C, the fractions of all normal sera showed two characteristic peaks of MSS activity. The pattern differed in heated serum fractions of CF patients, in that the second peak was lacking in 59% of individual tests. The pattern was intermediate in heterozygote sera. Of the 36 CF serum fractions which did have two peaks of activity, 89% had the predominant activity in peak 1. The frequency of single peaks of activity increased with patient age, from 33% in those under 10 years to 75% in those over 16. The molecular weight of peak 1 is about 75,000 daltons, of peak 2 about 30,000. One may speculate that the frequent lack of peak 2 serum components may be associated with the inability of most CF patients to produce normal mucus following respiratory infection.

Maseria vespertilionis n.g., n.sp. (Dorylaimina : Muspiceidae), a nematode from nearctic bats (Vespertilionidae).

Maseria vespertilionis n. g., n. sp. (Dorylaimina : Muspiceidae) is described from nearctic bats (Vespertilionidae). In addition to the type host, Eptesicus fuscus (P. de Beauvois), in Oregon, M. vespertilionis was recorded from Myotis volans (Allen) in Oregon, and from M. lucifugus (Le Conte) in Oregon and Alaska. The nematode was found only in subcutaneous tissues near the plantar surface of the rear feet of the host. The genus Maseria is distinguished from other genera in Muspiceidae by various morphological characteristics, among which the presence of a Demanian system is important. The lesions produced in the feet of the host are described, and other biological characteristics of the nematode are discussed.