Visual pigment molecular evolution in the Trinidadian pike cichlid (Crenicichla frenata): a less colorful world for neotropical cichlids?

The Trinidadian pike cichlid (Crenicichla frenata) is a major predator of the guppy (Poecilia reticulata), a model system for visual ecology research, and visual predation by the pike cichlid is known to select for male guppies with reduced short-wavelength reflectance. However, an early study of the pike cichlid's visual system suggested a lack of short-wavelength-sensitive cone photoreceptors, a surprising finding as many African cichlids have highly developed short-wavelength vision. In this study, we found evidence for only four expressed cone opsins (LWS, RH2a, SWS2a, and SWS2b), plus one pseudogene (RH2b). Taken together with our microspectrophotometry data, which revealed the presence of three types of cone photoreceptor, including one sensitive to short-wavelength light, this would indicate a broader spectral capacity than previously believed from earlier visual studies of this fish. Relative to the highly diverse African cichlids, however, this Neotropical cichlid appears to have a greatly reduced opsin complement, reflecting both gene loss along the Neotropical lineage (lacking functional RH2b and, possibly, SWS1 opsins) and gene duplication within the African clade (which possesses paralogous RH2aα and RH2aß opsins). Molecular evolutionary analyses show that positive selection has shaped the SWS2b and RH1 opsins along the Neotropical lineage, which may be indicative of adaptive evolution to alter nonspectral aspects of opsin biology. These results represent the first molecular evolutionary study of visual pigments in a Neotropical cichlid and thus provide a foundation for further study of a morphologically and ecologically diverse clade that has been understudied with respect to the link between visual ecology and diversification.

Sperm morphology of beef bulls evaluated by two different methods.

The objectives of this study were to compare two different methods of evaluating bull sperm morphology, bright-field (BF) microscopy of eosin-nigrosin (EN) stained dry-mount semen smears and differential interference phase contrast (DIC) microscopy of wet-mount semen 'fixed' in isotonic formal saline, both at 1000x. Ejaculates (n=72) were evaluated, representing both pre- and post-breeding season ejaculates collected from 40 2-yr-old beef bulls via electro-ejaculation. For both methods, 200 sperm were counted in random fields with defects categorized as major (MAD) and minor (MID). Sperm abnormalities were also placed into two other categories: those considered to be most influenced by process (wet or dry, METHDEF) and those with depictions that could be influenced by optics (BF or DIC, OPTIDEF). Differences (P<0.05) occurred between DIC and BF methods respectively: MAD 23.3/16.1, MID 7.6/13.4, acrosome 3.8/1.1, midpiece 9.2/11.7, tail 2.0/4.7, droplets 8.3/4.2, METHDEF 14.2/21.4 and OPTIDEF 13.0/5.5, but not (P>0.05) in percent normal sperm 69.1/70.4 or sperm head defects 7.5/8.3. Acrosome, tail and droplet defects were observed in 98.2/80.5, 86.1/100 and 98.2/94.4 percent of bulls for DIC and BF, respectively (P<0.05). As percent normal sperm did not differ between methods, bright-field microscopy assessment of EN preparations was considered to be a satisfactory method to categorize breeding soundness of bulls. However, DIC was more effective in visualizing major defects, while BF (which included stained smear preparation) was considered to cause more minor defects. Thus DIC was considered to be the preferred method of semen assessment for accurate assessment of sperm morphology in bulls.

Percutaneous management of perianastomotic stenosis in arteriovenous fistulae: results of a prospective study.

Surgical creation of new anastomosis has been proposed as the preferred treatment for perianastomotic stenoses of fistulae. However, disadvantages of surgical approach have included (1) frequent conversion of fistula to a graft by using synthetic graft material to create a new anastomosis, (2) shortening the length of the cannulation segment by proximal autologous arteriovenous neoanastomosis, and (3) abandoning the fistula altogether in favor of a synthetic graft. We report the results of a prospective study using percutaneous balloon angioplasty (PTA) to treat fistulae with perianastomotic lesions. Seventy-three consecutive patients undergoing 112 PTA procedures for the treatment of perianastomotic lesions were studied. Primary and secondary patency rates were calculated. Procedure success, procedure-related complications, and conversion of fistulae to grafts were recorded. The initial success rate was 97%. The degree of stenosis before and after PTA was 81 +/- 9 and 11+/-11%, respectively. Primary patency rates at 6, 12, and 18 months were 75, 51, and 41%, respectively. Secondary patency rates at 6, 12, and 18 months were 94, 90, and 90%, respectively. Grade I hematoma occurred in three and vein rupture in two cases. No grafts were inserted. These outcomes are superior to those that have been reported for surgery. The outpatient PTA is safe and effective for the management of perianastomotic stenosis. Because of its advantage of fistula preservation, the percutaneous approach should be considered as the preferred first-line therapy for the management of perianastomotic fistula lesions.

Interspecific and intraspecific views of color signals in the strawberry poison frog Dendrobates pumilio.

Poison frogs in the anuran family Dendrobatidae use bright colors on their bodies to advertise toxicity. The species Dendrobates pumilio Schmidt 1858, the strawberry poison frog, shows extreme polymorphism in color and pattern in Panama. It is known that females of D. pumilio preferentially choose mates of their own color morph. Nevertheless, potential predators must clearly see and recognize all color morphs if the aposematic signaling system is to function effectively. We examined the ability of conspecifics and a model predator to discriminate a diverse selection of D. pumilio colors from each other and from background colors. Microspectrophotometry of isolated rod and cone photoreceptors of D. pumilio revealed the presence of a trichromatic photopic visual system. A typical tetrachromatic bird system was used for the model predator. Reflectance spectra of frog and background colors were obtained, and discrimination among spectra in natural illuminants was mathematically modeled. The results revealed that both D. pumilio and the model predator discriminate most colors quite well, both from each other and from typical backgrounds, with the predator generally performing somewhat better than the conspecifics. Each color morph displayed at least one color signal that is highly visible against backgrounds to both visual systems. Our results indicate that the colors displayed by the various color morphs of D. pumilio are effective signals both to conspecifics and to a model predator.

Feeding efficiency and respiratory integration in infants with acute viral bronchiolitis.

OBJECTIVE: To examine the effects of bronchiolitis on feeding efficiency and respiratory integration. STUDY DESIGN: We studied 21 infants with bronchiolitis and 21 bottle-fed healthy infants who formed a comparison group. Repeat evaluations of half the bronchiolitis group were performed during recovery. During each feeding study we measured the duration and frequency of sucking, the frequency of single and multiple swallows, the respiratory rate, the postswallow respiratory direction, and the suck and swallow volumes. RESULTS: The infants with bronchiolitis devoted significantly less time to sucking than their healthy peers (P <.05), and the mean suck volume was reduced. Although the frequency of swallowing was slightly higher, the volume of milk consumed per swallow was almost half the amount consumed by the comparison group (P <.01). Coordination of breathing with swallowing was also less effective (P <.01). CONCLUSION: Although most aspects of feeding are less efficient during periods of respiratory illness, others are preserved or recover rapidly. Coordination of breathing during feeding is also significantly impaired.

A randomized, double-blind, placebo-controlled trial of prophylactic recombinant human granulocyte-macrophage colony-stimulating factor to reduce nosocomial infections in very low birth weight neonates.

OBJECTIVE: We carried out a randomized placebo-controlled trial in very low birth weight neonates (VLBWNs), comparing the incidence of nosocomial infections after the prophylactic use of recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) versus placebo in VLBWNs. STUDY DESIGN: VLBWNs (n = 264), weighing 501 to 1000 g, /=4000/mm,3 peripheral blood progenitor studies, and 24-hour polymorphonuclear leukocyte C3bi receptor expression were compared between the 2 treatment groups. RESULTS: No (grade III/IV) toxicity or adverse events were associated with rhu GM-CSF. The absolute neutrophil count and absolute eosinophil count were significantly elevated in the rhu GM-CSF group on days 7 (P =.001), 14 (P =.001), and 21 (P =.007) and on days 7 and 28 (P =.012 and P =.001, respectively). However, there was no difference in the incidence of confirmed nosocomial infections between the 2 treatment groups in this trial (40% vs 39%, rhu GM-CSF vs placebo; P = NS). CONCLUSION: In a large randomized placebo-controlled trial, prophylactic administration of rhu GM-CSF in VLBWNs does not appear to decrease the incidence of nosocomial infections.

A two-year follow-up of neonates with presumed sepsis treated with recombinant human granulocyte colony-stimulating factor during the first week of life.

We have previously reported that recombinant human granulocyte colony-stimulating factor was well tolerated and resulted in sustained neutrophilia and improvement of neutrophil functions in newborn infants with presumed sepsis. We now report a 2-year follow-up on 21 of the initial cohort of 28 patients. Treatment with recombinant human granulocyte colony-stimulating factor in neonates with presumed sepsis was not associated with any long-term adverse hematologic, immunologic, or developmental effects.

Cloning and expression of cDNA encoding antistasin, a leech-derived protein having anti-coagulant and anti-metastatic properties.

As a factor Xa inhibitor, antistasin is a potent anti-coagulant and anti-metastatic agent that is found in the salivary gland of the Mexican leech Haementaria officinalis. cDNA clones that encode antistasin have been isolated. Subsequent sequence analysis and comparison with the amino acid sequence of the mature protein indicates that antistasin is produced as a pre-protein containing a 17-amino acid signal peptide. Antistasin exists as at least two variants. By sequence analysis of multiple cDNA clones, we found two additional sites for amino acid substitutions, confirming variants that differ from each other by amino acid changes at a minimum of four residues. These sequence variations appear to be the result of allelic variation rather than gene duplication as deduced from DNA blot analyses. Sequence data suggest that antistasin may have evolved from a smaller ancestral gene by a duplication event giving rise to a two-fold structural homology between the N- and C-terminal halves of the molecule. Insect cells transfected with a recombinant baculovirus expressed antistasin which was biologically active and had an electrophoretic mobility identical to that of the native molecule.

Prophylaxis of varicella in high-risk children: dose-response effect of zoster immune globulin.

Immunodeficient patients who were presumed to be susceptible received zoster immune globulin prophylaxis after exposure to varicella. The highest clinical attack rate (35.9%) was seen in household contacts; the lowest attack rate (0%) was observed in children exposed at school. Among household contacts, 48 of 100 patients who received high titer ZIG (reciprocal complement fixation titer greater than or equal to 2,560) developed fourfold rises in serum CF antibody between pre- and 48-hour post-treatment specimens, compared to only one of 34 patients treated with lower titer ZIG lots (P less than 0.001). Patients who developed fourfold antibody rises were significantly less likely to contract clinical varicella (P less than 0.01). Patients who received high titer ZIG also had significantly lower risks of death (P = 0.025) and complications (P = 0.006). Among ZIG-treated patients who contracted clinical varicella, 80% developed mild disease (less than 100 pox), and the median incubation period was prolonged. Immunodeficient children exposed to varicella benefit from ZIG prophylaxis and higher titer ZIG is of greatest benefit.

Clasificación tratamiento de los traumatismos de los dientes en niños: manual para estudiantes y prácticas generales

Introducción. Dientes anteriores. Clase 1: fractura coronaria simple con poca o ninguna dentina afectada. Clase 2: fracturas coronaria extensa que afecta considerable dentina pero no la pulpa. Clase 3: fractura coronaria con considerable dentina afectada y exposición pulpar. Clase 4: diente traumatizado con desvitalización, con o sin pérdida de estructura coronaria. Clase 5: dientes perdidos como resultado de traumatismos. Clase 6: fractura radicular con o sin pérdida de tejidos coronarios. Clase 7: desplazamiento dentario sin fractura coronaria ni radicular. Clase 8: Fractura coronaria en masa y su reemplazo. Clase 9: Traumatismos de dientes primarios

Clasificación y tratamiento de los traumatismos de los dientes en niños: manual para estudiantes y prácticas generales

Introducción. Dientes anteriores. Clase 1: fractura coronaria simple con poca o ninguna dentina afectada. Clase 2: fracturas coronaria extensa que afecta considerable dentina pero no la pulpa. Clase 3: fractura coronaria con considerable dentina afectada y exposición pulpar. Clase 4: diente traumatizado con desvitalización, con o sin pérdida de estructura coronaria. Clase 5: dientes perdidos como resultado de traumatismos. Clase 6: fractura radicular con o sin pérdida de tejidos coronarios. Clase 7: desplazamiento dentario sin fractura coronaria ni radicular. Clase 8: Fractura coronaria en masa y su reemplazo. Clase 9: Traumatismos de dientes primarios

Clasificación y tratamiento de los traumatismos de los dientes en niños: manual para estudiantes y prácticas generales

Introducción. Dientes anteriores. Clase 1: fractura coronaria simple con poca o ninguna dentina afectada. Clase 2: fracturas coronaria extensa que afecta considerable dentina pero no la pulpa. Clase 3: fractura coronaria con considerable dentina afectada y exposición pulpar. Clase 4: diente traumatizado con desvitalización, con o sin pérdida de estructura coronaria. Clase 5: dientes perdidos como resultado de traumatismos. Clase 6: fractura radicular con o sin pérdida de tejidos coronarios. Clase 7: desplazamiento dentario sin fractura coronaria ni radicular. Clase 8: Fractura coronaria en masa y su reemplazo. Clase 9: Traumatismos de dientes primarios