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.     

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.     

An outbreak of leptospirosis in seals (Phoca vitulina) in captivity

An outbreak of leptospirosis in seals (Phoca vitulina) in captivity is described. In a zoo in The Netherlands 5 adult seals died within 12 days. At necropsy all animals showed signs of acute septicaemia, consistent with acute leptospirosis. Serological examination of one animal was positive for antibodies against Leptospira interrogans serovar Icterohaemorrhagiae and the serologically closely related serovar Copenhageni. Polymerase chain reaction was positive in one other animal. 8 nutria (Myocastor coypus) were examined, serologically, through bacteriological culture and PCR. 81,8% (9/11) were serologically positive for Leptospira. The seals and nutria were housed in the same water system.     

Les sucres de la racine de carotte cultivée (variété Nantaise demi-longue): Variations climatiques et saisonnières,répartition dans les tissus,modification au cours du stockage

In the cultivated carrot, carbohydrate reserves consists of glucose, fructose, saccharose and occasionally small quantities of starch. Pectins, although quite abundant, do not however seem to constitute a reserve material for the plant.The carbohydrate composition of the root varies considerably during its development leading especially to an abrupt change in the respective proportions of saccharose and reducing sugars during what may be called the period of ripening. Thus the level of saccharose doubles while the concentrations of glucose and fructose are reduced by about 40 and 65% respectively. Once ripening is over the carbohydrate reserves accumulate steadily to attain an increase of about 35% in the case of saccharose and 30% in that of reducing sugars.Climatic and ecological factors exert an undeniable influence on the level and the type of carbohydrate reserves, but the intensity of their effect does not exceed that of the variations observed between tuberous roots of the same lot harvested at different times after ripening.Individual variations in the carbohydrate composition of the roots of the same stock observed at a given time may attain 40% of the mean value of total sugars with deviations of up to 100% for saccharose, 30% for glucose and 60% for fructose. Sugar content is not directly related to the weight of the organ.The xylem and the phloem parenchymas of carrot roots differ in their carbohydrate composition which is of the same level when expressed in terms of total sugar per dry weight, but the proportion of saccharose is less in the xylem than in the phloem. This may indicate distinct types of metabolism, the more so as the xylem has a higher water content. In a single parenchyma the distribution of sugars in each xylem or phloem can be very uneven; thus the apex is generally richer in total sugar than the base, though the latter has the highest level of saccharose.The heterogeneity in the distribution of sugars observed in the mass of a tuberous root can therefore be easily explained by the uneven distribution of xylem and phloem parenchymas, whose composition is different and, besides, not uniform over the length of the root.Changes in reserve sugars are produced in carrots stocked during winter. There is usually a drop in reducing sugars, while saccharose remains constant in roots that retain most of their moisture in silos, and increases in roots that undergo partial drying in cellars. In the latter case a condensation of saccharose from reducing sugars can be imagined to compensate for the increase in the osmotic pressure of the cell sap that follows drying.

---

Zusammenfassung Die Reserven an Kohlenhydraten bestehen in der Karotte aus Glukose, Fruktose, Saccharose und manchmal auch aus kleineren Mengen an Stärke. Die ebenfalls reichlich vorhandenen Pektine, scheinen währenddessen für die Pflanze keine Reservestoffe zu sein.Die Zusammensetzung der verschiedenen Kohlenhydrate, im Laufe der Entwicklung der Wurzel zu einem gegebenen Zeitpunkt Maturation genannt, macht eine plötzliche Veränderung bezüglich des Verhältnisses von Saccharose zu reduziertem Zucker durch. Der Anteil von Saccharose steigt auf das Doppelte, während sich die Konzentration von Glukose und Fruktose um 40 und 65% vermindert. Nach vollendeter Maturation stellt man fest, daß sich die Anhäufung von Kohlenhydrat-Reserven fortsetzt, im Laufe der Zeit kann sich also der Gehalt an Saccharose um 35% vermehren, der an reduzierendem Zucker um ungefähr 30%.Die klimatischen und ökologischen Faktoren üben einen bedeutenden Einfluß auf den Gehalt und die Art der Kohlenhydrat-Reserven aus, ihre Wirkung scheint aber nicht die genetischen Unterschiede der einzelnen Individuen zu übertreffen, die man bei Wurzeln gleicher Ernten zu verschiedenen Terminen nach der Maturation beobachten kann.Die individuellen Veränderungen der Kohlenhydrat-Zusammensetzung der Wurzeln der gleichen Aussaat, die zu einem gegebenen Zeitpunkt geerntet werden, können 40% des mittleren Wertes des Gesamt-Zuckers, mit Unterschieden von 100% an Saccharose, von 30% an Glukose und von 60% an Fruktose erreichen.Der Gehalt an Zucker in den Wurzeln steht in keiner direkten Beziehung zum Organgewicht. Die Parenchyme Xylem und Phloem der Karottenwurzel haben eine verschiedene Kohlenhydrat-Zusammensetzung. Sie besitzen fast den gleichen Gehalt des Gesamt-Zuckers bezogen auf das Trockengewicht, aber das Verhältnis der Saccharose ist bedeutend niedriger im Xylem als im Phloem, worauf gut auf den unterschiedlichen Metabolismus zu schließen ist, zumal das Xylem mehr Wasser als das Phloem enthält. Im gleichen Parenchym erweist sich die Verteilung der Kohlenhydrate als sehr ungleich: die Spitze des Organs ist im allgemeinen viel reicher an Gesamt-Zucker als der obere Teil unter den Blättern, der Anteil an Saccharose ist jedoch in diesem Teil höher. Die ungleichförmige Verteilung des Zuckers in einer Wurzel erklärt sich dann leicht durch die ungleiche Verbreitung von Xylem- und Phloemparenchym, dessen Zusammensetzung verschieden ist und unter anderem für beide variabel in seiner ganzen Größe ist.In den während des Winters gelagerten Karotten vollzieht sich eine Umwandlung der Reserven an Kohlenhydraten. Immer findet ein Absinken des Gehaltes an reduzierendem Zucker statt. Während der Gehalt an Saccharose konstant bleibt, wenn die Wurzeln in feucht gehaltenen Silos gelagert werden, findet eine Erhöhung statt, wenn die Karotten bei Kellerlagerung teilweise austrocknen. Wir können uns denken, daß es sich in diesem letzten Fall um eine Kondensation von Saccharose aus einem Teil des reduzierenden Zuckers handelt, um die infolge Wasserverlust durch Austrocknung bedingte Erhöhung des osmotischen Drucks auszugleichen, der durch die Konzentration des vakuolären Saftes aufrecht erhalten wird.

     

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.