Expansion of the dentate mossy fiber-CA3 projection in the brain-derived neurotrophic factor-enriched mouse hippocampus.

Structural changes that alter hippocampal functional circuitry are implicated in learning impairments, mood disorders and epilepsy. Reorganization of mossy fiber (MF) axons from dentate granule cells is one such form of plasticity. Increased neurotrophin signaling is proposed to underlie MF plasticity, and there is evidence to support a mechanistic role for brain-derived neurotrophic factor (BDNF) in this process. Transgenic mice overexpressing BDNF in the forebrain under the α-calcium/calmodulin-dependent protein kinase II promoter (TgBDNF mice) exhibit spatial learning deficits at 2-3months of age, followed by the emergence of spontaneous seizures at ∼6months. These behavioral changes suggest that chronic increases in BDNF progressively disrupt hippocampal functional organization. To determine if the dentate MF pathway is structurally altered in this strain, the present study employed Timm staining and design-based stereology to compare MF distribution and projection volumes in transgenic and wild-type mice at 2-3months, and at 6-7months. Mice in the latter age group were assessed for seizure vulnerability with a low dose of pilocarpine given 2h before euthanasia. At 2-3months, TgBDNF mice showed moderate expansion of CA3-projecting MFs (∼20%), with increased volumes measured in the suprapyramidal (SP-MF) and intra/infrapyramidal (IIP-MF) compartments. At 6-7months, a subset of transgenic mice exhibited increased seizure susceptibility, along with an increase in IIP-MF volume (∼30%). No evidence of MF sprouting was seen in the inner molecular layer. Additional stereological analyses demonstrated significant increases in molecular layer (ML) volume in TgBDNF mice at both ages, as well as an increase in granule cell number by 8months of age. Collectively, these results indicate that sustained increases in endogenous BDNF modify dentate structural organization over time, and may thereby contribute to the development of pro-epileptic circuitry.

Prenatal sonographic diagnosis of a congenital oral fibrovascular hamartoma.

We report the diagnosis of a congenital oral fibrovascular hamartoma with two- and three-dimensional ultrasound. The distinctive sonographic features including the fibrovascular stalk and a single vascular pedicle are described. Prenatal magnetic resonance imaging and postnatal computed tomography confirmed the ultrasound findings. Despite concerns about impaired swallowing, the prenatal and perinatal courses were straightforward. The lesion was removed soon after birth. Histopathology of the removed lesion provided the definitive diagnosis of a fibrovascular hamartoma and reported a cellular composition that differentiates it from similar lesions. To our knowledge, such a lesion has not been reported pre- or postnatally and provides an alternative differential diagnosis for a fetus presenting with a mouth mass.

Spectral Doppler waveforms in systemic arteries and physiological significance of a patent ductus arteriosus.

Patent ductus arteriosus in extremely premature babies is associated with major neonatal morbidities, such as necrotizing enterocolitis and intraventricular hemorrhage. This may be attributable, at least in part, to systemic hypoperfusion secondary to ductal steal. A hemodynamically significant ductus arteriosus (HSDA) is known to be associated with altered systemic blood flow and end-organ hypoperfusion. Although descending aorta blood flow profiles may show abnormal diastolic retrograde flow, Doppler studies of blood flow in the systemic arteries may help improve our understanding of the relationship of a HSDA with these morbidities. In this article, we discuss aspects of diastolic blood flow reversal in the systemic arteries in premature infants with a hemodynamically significant duct. Whether these hemodynamic effects are significant enough to form the basis for initiating treatment is still unclear; these should form the basis for prospective studies.

Sedimentary records of sewage pollution using faecal markers in contrasting peri-urban shallow lakes.

Sewage contamination in shallow lake sediments is of concern because the pathogens, organic matter and nutrients contribute to the deterioration of the water-bodies' health and ecology. Sediment cores from three shallow lakes (Coneries, Church and Clifton Ponds) within Attenborough nature reserve located downstream of sewage treatment works were analysed for TOC, C/N, δ(13)C, δ(15)N, bacterial coliforms and faecal sterols. (210)Pb and (137)Cs activities were used to date the sediments. Elemental analysis suggests that the source of organic matter was algal and down profile changes in δ(13)C indicate a possible decrease in productivity with time which could be due to improvements in sewage treatment. δ(15)N for Coneries Pond are slightly higher than those observed in Church or Clifton and are consistent with a sewage-derived nitrate source which has been diluted by non-sewage sources of N. The similarity in δ(15)N values (+12 ‰ to +10 ‰) indicates that the three ponds were not entirely hydrologically isolated. Analysis by gas chromatography/mass spectrometry (GC/MS) reveals that Coneries Pond had sterol concentrations in the range 20 to 30 µg/g (dry wt.), whereas, those from Clifton and Church Ponds were lower. The highest concentrations of the human-sourced sewage marker 5ß-coprostanol were observed in the top 40 cm of Coneries Pond with values up to 2.2 µg/g. In contrast, Church and Clifton Pond sediments contain only trace amounts throughout. Down-profile comparison of 5ß-coprostanol/cholesterol, 5ß-coprostanol/(5ß-coprostanol+5α-cholestanol) and 5ß-epicoprostanol/coprostanol as well as 5α-cholestanol/cholesterol suggests that Coneries Pond has received appreciable amounts of faecal contamination. Examination of 5ß-stigmastanol (marker for herbivorous/ruminant animals) down core concentrations suggests a recent decrease in manure slurry input to Coneries Pond. The greater concentration of ß-sitosterol in sediments from Church and Clifton Ponds as compared to Coneries is attributed in part to their greater diversity and extent of aquatic plants and avian faeces.

Ultrasound imaging of the patellar tendon attachment to the tibia during puberty: a 12-month follow-up in tennis players.

This longitudinal study investigated the ultrasound appearance of the patellar tendon attachment to the tibia throughout puberty in young tennis players with and without Osgood-Schlatter disease (OSD). Twenty-eight competitive players (17 boys), aged 10.6-15.3 years, had bilateral ultrasound imaging of the patellar tendon attachment to the tibia at baseline and 1 year later. On each occasion, anthropometric measurements, pubertal status and injury history were recorded. Ultrasound appearance of the patellar tendon attachment was categorized into three stages: cartilage attachment, insertional cartilage and mature attachment. Stage 1 appearance, a large anechoic region with or without ossicles and irregularity of the apophysis that are classically associated with OSD, was found in eight players, seven of them were pain free. A majority (62%) of the patellar tendons in stage 1 at baseline progressed toward stage 2 or stage 3 1 year later. Likewise the patellar tendon attachment in most athletes with cartilage insertion showed progression to a mature enthesis over 1 year. The imaging appearance that is classically interpreted as OSD was common in asymptomatic knees. This ultrasonographic description of the patellar tendon attachment to the tibia during growth provides a reference for the assessment of bone tendon attachments in adolescents.

Sonographic identification of lower limb venous hypoplasia in the prenatal diagnosis of Klippel-Trénaunay syndrome.

We report the prenatal identification of lower-limb venous hypoplasia to support a provisional prenatal diagnosis of Klippel-Trénaunay syndrome (KTS). Ultrasound assessment of a fetus with marked lower-limb edema, cystic areas in the abdomen/pelvis/lower limbs and abnormal development of the feet demonstrated bilateral hypoplasia of the femoral and popliteal veins. The external iliac veins and the great saphenous veins were seen to be normal. The lower limb arterial system was present. These findings supported KTS as the most likely provisional diagnosis, and postnatal clinical evaluation confirmed that the infant is best classified in the spectrum of KTS. Venous hypoplasia was confirmed with a postnatal ultrasound examination of the lower limbs. This case suggests that careful examination of the lower-limb venous system may be helpful in making the prenatal diagnosis of KTS.