Changes in calmodulin level after fertilization and during first cleavage in the egg of the urodelan amphibian Pleurodeles waltlii

We report three significant calmodulin rises related to Pleurodeles waltlii egg fertilization and following developmental events. These elevations are correlated to the major obvious Ca2+-dependent events: Na+-H+ exchange, activation of NAD kinase, triggering of cortical reaction, resumption of meiotic division II, initiation of DNA synthesis and regulation of cell division. Therefore, it is suggested that alterations in calmodulin level in fertilized egg may be part of the Ca2+-dependent regulatory mechanisms which turn on metabolisms, initiate development and govern cell cleavages.     

DNA Changes in Spinal Cords of Rats with Experimental Allergic Encephalomyelitis

DNA levels were measured in the spinal cords of Lewis rats during the development of and recovery from experimental allergic encephalomyelitis (EAE). Spinal cord DNA was first increased 11 days after immunizing the rats with guinea pig myelin and rose to levels four times that of the Freund's adjuvant controls at day 14, then subsided after day 22. Spinal cord DNA was still 150% of control levels 60 days after immunization. These DNA changes were compared with fluctuations in spinal cord acid proteinase in the same animals. Acid proteinase activity in EAE spinal cord increased later than the rise in DNA and attained a level of 170% of control at days 15-17, then subsided. Spinal cord DNA was higher in rats immunized with whole myelin than in those administered equivalent amounts of purified myelin basic protein. Furthermore DNA was higher in spinal cords of rats immunized with a larger dose of myelin (1.0 mg) than with a lower amount (0.5 mg). Various protease inhibitors including pepstatin, nitrophenyl p-guanidino benzoate, polylysine, and dipropionyl rhein, previously shown to protect Lewis rats against EAE, suppressed the increase of DNA in the spinal cord. Measurement of DNA increases in the spinal cord of EAE animals provides a convenient reproducible measurement of the severity of inflammation in the CNS and provides an objective criterion for assessment of the efficacy of various agents screened as possible therapeutic treatment for multiple sclerosis.     

The antagonism of bombesin in the CNS by substance P analogues

The ability of substance P analogues to inhibit the action of bombesin in the CNS was investigated using receptor binding and biological assays. The putative substance P antagonists inhibited binding to central receptors for both substance P and bombesin-like peptides. Spantide, which was the most potent analogue tested, reversed the bombesin induced hypothermia and grooming. Therefore the putative substance P antagonists may also antagonize the actions of bombesin in the CNS     

The spinning apparatus of Polenecia producta (Araneae,Uloboridae): Structure and histochemistry

Summary The spinning apparatus of the uloborid spider Polenecia producta was studied to complete previous studies on the same family of spiders. The structure of spinnerets and spigots, under scanning electron microscopy, and the main anatomical and histochemical characteristics of the spinning glands of adult females and males are described. In addition some observations on the spinning apparatus at three successive stages of development are made. There are nine kinds of silk glands in Polenecia, i.e. one more (aciniform — B glands) than found in other uloborids. The spinning apparatus of Polenecia is, therefore, the most complex so far known. It is also more complex than that presently known of Araneoidea. The characteristics of the spinning glands of Polenecia are compared with those of other uloborids. Present knowledge of the spinning apparatus of uloborids leads to a renewed discussion of the origin of the orb web in this family and in araneids. It is concluded that these two types of orb webs emerged from independent evolutionary processes.     

A cell culture model of chemically and spontaneously derived mouse lung alveologenic carcinoma

Malignant cell lines related to mouse lung alveologenic carcinoma have been established from urethane-induced tumors and after in vitro spontaneous transformation of preneoplastic cell lines. Both the chemically and spontaneously transformed cell lines formed invasive, poorly differentiated carcinomas with secondary lung deposits when implanted subcutaneously in immune-suppressed mice. They differed from the related preneoplastic cell line in coordinately exhibiting anchorage-independent growth, reduced epidermal growth factor receptor activity and absence of pericellular fibronectin. These data suggest that similar molecular events may occur in type 2 pneumocyte-related cells in order to generate mouse lung alveologenic adenomas and carcinomas by both spontaneous and chemical carcinogen induction mechanisms. A reduced level of pericellular fibronectin was also demonstrated in an in situ compressive urethane-induced mouse lung adenoma. Loss of pericellular fibronectin may therefore be an early and persistent phenotypic alteration during transformation to the alveologenic adenoma and carcinoma.Abbreviations EGF epidermal growth factor - TGF transforming growth factor     

Comparison of the structure of HLA-Bw47 to HLA-B13 and its relationship to 21-hydroxylase deficiency

Adrenal 21-hydroxylase deficiency is strongly associated with HLA-Bw47. This rare HLA allele and the HLA-B13 allele are both found in positive genetic linkage disequilibrium with HLA-A3, -Cw6, -DR7 and also display serological cross-reactivity. To investigate the relationship between these two alleles at the structural level, the nucleotide sequences of the HLA-B13 and HLA-Bw47 genes have been determined. They differ by 28 nucleotides, resulting in 14 amino acid substitutions: 5 in the 1 domain, 8 in the 2 domain, and 1 in the transmembrane region. Comparison of HLA-Bw47 nucleotide sequence with other HLA-B sequences shows a segment of 228 by identical with B44 in the a 1 domain and a segment of 218 by identical with B27 in the a2 domain, but only a 91 by segment of identity with B13 in the al domain. The complex pattern of substitutions and their degree of divergence indicate that HLA-B13 and HLA-Bw47 alleles are not related by a simple mutational event.     

Filter Paper Dot-Immunobinding Assay for Detection of Spiroplasma citri

A rapid filter paper dot-immunobinding assay was adapted to detect the wall-less mollicute Spiroplasma citri in medium, plants, or insects. Filter paper spotted with sample was incubated first in dilute antiserum, then in protein A-peroxidase, and finally in a substrate of 4-chloro-1-naphthol plus hydrogen peroxide. The detection limit averaged 2.3 × 10¹⁰ CFU/ml in cultures, and S. citri was detected in single infected leafhoppers. This assay was less sensitive but more rapid and economical than an enzyme-linked immunosorbent assay.     

Effects of reproductive state on concentrations of thyroxine, 3,5,3'-triiodothyronine and cortisol in serum of dogs

Reproductive state of animals frequently is overlooked when examining endocrine functions of the thyroid gland and adrenal cortex. This experiment was done to determine effects of reproductive state on basal and stimulated concentrations of thyroxine (total T4), 3,5,3'-triiodothyronine (total T3) and cortisol in serum of adult Beagle dogs. Five male, 5 anestrous, 5 proestrous, 5 diestrous, 5 pregnant and 5 lactating dogs were fasted for 18 h before each dog received 5 IU of thyrotropic hormone (TSH) i.v. and 2.2 IU/kg of body weight of adrenocorticotropic hormone (ACTH) i.m. Blood samples were collected via jugular cannulas or by jugular venipuncture at 60, 45, 30, 15 and 1 min before and 0.5, 1, 2, 3, 4, 5, 8, 12 and 24 h after injection. Concentrations of T4 were similar in serum from diestrous and pregnant bitches but were greater (P less than 0.025) than those in dogs of other reproductive states before and after treatment with TSH. Concentrations of T3 were greater (P less than 0.005) in serum from diestrous bitches before and after TSH injection than in serum from dogs of all other reproductive states. Concentrations of T3 in males, anestrus, proestrus, pregnancy and lactation did not differ. Basal concentrations of cortisol did not differ consistently among reproductive states. However, concentrations post-ACTH were different (P less than 0.05) with anestrus = diestrus greater than lactation = pregnancy = male greater than proestrus. These results indicate that reproductive state of experimental animals must be considered when studying thyroidal and adrenal functions.     

Behavior of fish predators and their prey: habitat choice between open water and dense vegetation

Synopsis Behavior of largemouth bass, Micropterus salmoides, and northern pike, Esox lucius, foraging on fathead minnows, Pimephales promelas, or bluegills, Lepomis macrochirus, was quantified in pools with 50% cover (half the pool had artificial stems at a density of 1000 stems m⁻²). Both predators spent most of their time in the vegetation. Largemouth bass searched for bluegills and ambushed minnows, whereas the relatively immobile northern pike ambushed all prey. Minnows were closer to predators and were captured more frequently than bluegills. Even when minnows dispersed, they moved continually and eventually wandered within striking distance of a predator. Bluegills dispersed in the cover with predators. Bass captured the few bluegills that strayed into the open and pike captured those that approached too closely in the cover. The ability of predators to capture prey while residing in habitats containing patches of dense cover may explain their residence in areas often considered to be poor ones for foraging. The unit is sponsored jointly by the United States Fish and Wildlife Service, Ohio Department of NaturalResources, The Ohio State University, and the Wildlife Management Institute     

Ontogeny and phylogeny of the trunk lateral line system in cichlid fishes

An examination of the ontogeny of the lateral line trunk canal and the diversity of adult trunk canal patterns among cichlids indicates that bidirectional canal formation is a general ontogenetic pattern in the Cichlidae with the exception of Cichla and those few species with a complete trunk canal pattern. In addition to the tubed scales which make up the trunk canal, some lateral line scales have pits containing superficial neuromasts. These are recognized as components of the lateral line system of the trunk in adult cichlids for the first time. Eight trunk canal patterns that are variations on a simple disjunct pattern are defined among the 17 cichlid genera examined. Using bidirectional canal formation as a developmental model, these patterns can be placed along an ontogenetic spectrum. This suggests that heterochrony (alterations in the timing of development) is an important mechanism of evolutionary change in the lateral line system of the trunk in cichlid fishes.