Pyometra and Pregnancy with Herlyn-Werner-Wunderlich Syndrome

We describe a Herlyn-Werner-Wunderlich syndrome (HWWS) patient with previous history of infertility who got pregnant without treatment and presented a pyometra in the contralateral uterus throughout the gestational period, despite multiple antibiotic treatments. Due to the uterus' congenital anomaly and the possibility of ascending infection with subsequent abortion, this pregnancy was classified as high-risk. We believe that the partial horizontal septum in the vagina may have contributed to the closure of the gravid uterus cervix, thus ensuring that the pregnancy came to term, with an uneventful vaginal delivery.

A new species of Moenkhausia Eigenmann (Characiformes: Characidae) from the rio Xingu basin, Brazil

A new species of Moenkhausia from the upper rio Xingu basin is described. Moenkhausia eurystaenia is distinguished from all congeners, except M. heikoi and M. phaeonota, by the presence of a dark, broad longitudinal stripe from the opercle to the end of caudal peduncle. The new species is distinguished from M. heikoi mainly by having 18-21 branched anal-fin rays (vs. 24-26) and the absence of a round blotch at the end of the caudal peduncle (vs. present). Moenkhausia eurystaenia can be distinguished from M. phaeonota mainly by the anterior portion of longitudinal band darker at horizontal septum (vs. darker below horizontal septum), the deep dark pigmentation along horizontal septum extending anteriorly up to humeral region (vs. extending up to vertical through pelvic-fin origin), number of vertebrae 34 (vs. 36-37), and others additional measurements.

A mechanical analysis of myomere shape in fish

An architectural analysis is offered of the trunk muscles in fish, which are arranged in a longitudinal series of geometrically complex myomeres. The myomeres are separated by myosepta, collagenous sheets with complex fibre patterns. The muscle fibres in the myomeres are also arranged in complex three-dimensional patterns. Previously, it has been proposed that the muscle fibre arrangement allows for a uniform strain distribution within the muscle. Physical constraints limit the range of shapes that fibre-reinforced materials such as muscles can adopt, irrespective of their genetic profile. The three-dimensional shapes of myosepta are predicted by mechanical modelling from the requirements for mechanical stability and prescribed muscle fibre arrangements. The model can also be used to study the force transmission and likely locations of ligaments and bones in the myosepta. The model shows that the dorsal and ventral fins are located such that unfavourable mechanical interactions with the trunk muscles are avoided. In bony fish, extensive muscular deformations (notably in the region of the horizontal septum) that would not contribute to bending are avoided by the mechanical support of the skin, intramuscular bones and ribs. In sharks, the skin plays a more prominent role in avoiding such deformations because of the absence of bony elements.

Embryonic temperature modulates muscle growth characteristics in larval and juvenile herring

The influence of embryonic and larval temperature regime on muscle growth was investigated in Atlantic herring (Clupea harengus L.). Eggs of spring-spawning Clyde herring were incubated at 5 degrees C, 8 degrees C or 12 degrees C until hatching and then reared until after metamorphosis at rising temperatures to simulate a seasonal warming. Metamorphosis to the juvenile stage was complete at 37 mm total length (TL), after an estimated 177 days as a larva at 5 degrees C, 117 days at 8 degrees C and 101 days at 12 degrees C. Growth rate and the development of median fins were retarded in relation to body length at 5 degrees C compared with 8 degrees C and 12 degrees C. Between hatching (at 8-9 mm TL) and 16 mm TL, there was a threefold increase in total muscle cross-sectional area, largely due to the hypertrophy of the embryonic red and white muscle fibres. The recruitment of additional white muscle fibres started at approximately 15 mm TL at all temperatures, and by 37 mm was estimated to be 66 fibres day-1 at 5 degrees C and 103 fibres day-1 at 8 degrees C and 12 degrees C. Peptide mapping studies revealed a change in myosin heavy chain composition in white muscle fibres between 20 and 25 mm TL. Embryonic red muscle fibres expressed fast myosin light chains until 24-28 mm TL at 5 degrees C and 22 mm TL at 12 degrees C, and new red fibres were added at the horizontal septum starting at the same body lengths. Following metamorphosis, the total cross-sectional area of muscle was similar at different temperatures, although the number of red and white fibres per myotome was significantly greater at the warmest than at the coldest regime. For example, the mean number of white muscle fibres per myotome in 50 mm TL juveniles was calculated to be 23.4 % higher at 12 degrees C (12 065) than at 5 degrees C (9775). In other experiments, spring-spawning (Clyde) and autumn-spawning (Manx) herring were reared at different temperatures until first feeding and then transferred to ambient seawater temperature and fed ad libitum for constant periods. These experiments showed that, for both stocks, the temperature of embryonic development influenced the subsequent rate of muscle fibre recruitment and hypertrophy as well as the density of muscle nuclei. Labelling experiments with 5'-bromo-2-deoxyuridine showed that both the hypertrophy and recruitment of muscle fibres involved a rapidly proliferating population of myogenic precursor cells. The cellular mechanisms underlying the environmental modulation of muscle growth phenotype are discussed.

Spatial variation in epaxial muscle activity during prey strike in largemouth bass (Micropterus salmoides)

Epaxial muscle activity during prey strike was measured in two discrete myomeric regions of the largemouth bass Micropterus salmoides to test whether (1) the extreme dorsal region of the epaxial muscle (the epaxial arm region) plays a larger role in prey strike than the region bordering the main horizontal septum (the epaxial cone region), (2) whether the epaxial arm region is more active anteriorly than posteriorly during prey strike and (3) whether the epaxial arm region activity is correlated with the epaxial cone region activity. Electromyographic recordings (EMGs) of four bass were taken from eight different longitudinal, epaxial muscle sites: five sites in the arm region and three sites in the cone region. Selection of electrode sites was based on epaxial muscle dissections in which a set of previously undefined tendons, neurocranial-epineural-epaxial connector tendons, were described. Every strike had some activity in the arm region, while 48 % of the total number of prey strikes had zero cone activity. Muscle activity was recorded consistently from the first four anterior electrodes in the arm region of each fish, while the posteriormost arm electrodes showed varying degrees of activity. Muscle intensity recorded from the anterior three epaxial arm electrodes was consistently higher than from the two posterior epaxial arm electrodes, while the onset times and durations of EMGs were variable. Most notably, the arm region of the epaxial muscle is capable of being active without the adjoining cone region, thus demonstrating that activity in the epaxial muscle mass can be spatially regionalized in a manner dependent on behavior.