Design and fabrication of topologically complex, three-dimensional microstructures

Two concepts for use in the fabrication of three-dimensional (3D) microstructures with complex topologies are described. Both routes begin with a two-dimensional (2D) pattern and transform it into a 3D microstructure. The concepts are illustrated by use of soft lithographic techniques to transfer 2D patterns to cylindrical (pseudo-3D) substrates. Subsequent steps-application of uniaxial strain, connection of patterns on intersecting surfaces-transform these patterns into free-standing, 3D, noncylindrically symmetrical microstructures. Microelectrodeposition provides an additive method that strengthens thin metal designs produced by patterning, welds nonconnected structures, and enables the high-strain deformations required in one method to be carried out successfully.     

Detection of Mycobacterium avium subsp. paratuberculosis in skeletal muscle and blood of ewes from a sheep farm in New Zealand

Abstract

AIM: To determine whether viable Mycobacterium avium subsp. paratuberculosis (Map) is present in skeletal muscle and blood in ewes with and without Johne's disease confirmed histologically.

METHODS: A total of 51 mixed-aged ewes in poor body condition from a farm with a history of clinical Johne's disease were culled and examined at necropsy. BACTEC radiometric culture was performed on samples of skeletal muscle from the biceps femoris, mononuclear cells in peripheral blood (hereafter referred to as blood), and ileum. Histological sections and Ziehl-Neelsen (ZN)-stained impression smears of terminal ileum and mesenteric lymph nodes were examined. Ewes were defined as having confirmed Johne's disease if there was histopathological evidence typical of the disease within the ileum and adjacent lymph nodes.

RESULTS: Eighteen of 21 (86%) ewes with confirmed clinical Johne's disease were culture-positive for Map from sites peripheral to the alimentary tract, comprising 15 from skeletal muscle and 13 from blood. Five of 30 (17%) ewes that did not have Johne's disease were culture-positive, with four from skeletal muscle and one from blood. The likelihood that ewes with confirmed Johne's disease had systemic Map infection compared with ewes without was determined as OR=30 (95% CI=6.3–142.0; p<0.001).

CONCLUSION: The prevalence of Map infection of skeletal muscle and blood in ewes with confirmed Johne's disease was 71% and 62% respectively, and in unaffected ewes was 13% for muscle and 3% for blood.

CLINICAL RELEVANCE: Skeletal muscle and blood are potential sources of exposure of humans to Map, and the risk appears higher from sheep with Johne's disease.     

Lymphoedema — a problem of gigantic proportions

Extract

Lymphoedema (LO) is the accumulation of protein-rich interstitial fluid caused by failure of normal lymphatic drainage. Human lymphoedema is classified as primary (congenital hereditary or idiopathic, praecox or tarda forms) or secondary (complication of surgery or radiotherapy, such as that for breast cancer, as well as bancroftian filariasis, cellulitis and lymphangitis amongst others). Primary LO may be due to lymphatic aplasia, hypoplasia, dyspla-sia, lymphangiectasia, or aplasia or hypoplasia of draining lymph nodes. Approximately one in thirty people worldwide has LO.     

Effects of Serum Deprivation and Cycloheximide on Cell Cycle of Low and High Passage Porcine Fetal Fibroblasts

Arrest of cells in G0/G1 cell cycle phase is desired for nuclear transfer procedures. Serum starvation and cell cycle inhibitors are different ways to induce synchronization of the cell cycle. This study investigated the effects of serum starvation and cycloheximide (CHX) on the cell cycle of low (5th) and high (15th) passages fetal porcine fibroblasts. Cell cycle phases were determined using fluorescent activated cell sorting. Fifth passage fibroblast cultures had higher (p < 0.05) proportion of cells in G0/G1 only after 72 h of serum starvation (77.60 ± 0.65) when compared with non‐starved cells (71.44 ± 1.88). Serum starvation for all periods tested induced an increase (p < 0.05) on proportion of cells in G0/G1 on the 15th passage. No significant differences were observed on the 5th passage cultures exposed to CHX, although, on the 15th passage an increase on proportion of cells was observed after all periods of exposure (p < 0.05). These data indicates that high passage cells in vitro are more susceptible to serum starvation and CHX G0/G1 synchronization.     

Suspected Vestia foetida poisoning in young goats

CASE HISTORY: Two crossbred, castrated male goats, a 5-month-old and an 8-month-old, were observed ingesting Vestia foetida (Solanaceae). Later, the goats were seen standing splay-legged and apparently disoriented.

CLINICAL FINDINGS: When examined, both goats were in sternal recumbency and had mydriasis; the younger goat had a diminished menace response. When the goats were made to stand, they were ataxic and had muscle fasciculations of the hindquarters and face. Both had halitosis consistent with the odour of crushed Vestia leaves. The animals were treated with a mixture of vitamins and intravenous diazepam. The older goat recovered but the younger goat died and was necropsied. This animal had severe periacinar necrosis and fatty change in the liver, as well as fatty nephrosis.

DIAGNOSIS: Probable Vestia foetida poisoning.

CLINICAL RELEVANCE: The introduction of Vestia foetida to New Zealand and the apparent palatability of the plant necessitate that veterinarians and owners be knowledgeable about its potential toxicity. Differential diagnoses for the liver lesions (in New Zealand) would include Cestrum poisoning, acute seneciosis, acute blue-green algal poisoning, and acute and chronic copper poisoning.     

Pre-parturition staphylococcal mastitis in primiparous replacement goats: persistence over lactation and sources of infection

This investigation reported for the first time the occurrence of intramammary infections caused by Staphylococcus in primiparous replacement goats before parturition and the persistence of clinical Staphylococcus aureus infection during the lactation period. Subclinical infections, mainly caused by coagulase negative staphylococci (CoNS), did not persist during lactation. Genotyping analysis indicated that environment seems to play a moderate role as source of intramammary infections to goats before parturition, but causative agents of mastitis in lactating animals are not genotypically related to environmental staphylococci. The occurrence and persistence of intramammary infections in replacement goats demonstrate the need to consider those animals as potential sources of infections in dairy goat herds.