Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0344329 (collapse)
 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Single-strand interruptions in a template DNA are likely to cause collapse of replication forks. We propose a model for the repair of collapsed replication forks in Escherichia coli by the RecBCD recombinational pathway. The model gives reasons for the preferential orientation of Chi sites in the E. coli chromosome and accounts for the hyper-rec phenotype of the strains with increased numbers of single-strand interruptions in their DNA. On the basis of the model we offer schemes for various repeat-mediated recombinational events and discuss a mechanism for quasi-conservative DNA replication explaining the recombinational repair-associated mutagenesis.
 ...
PMID:Collapse and repair of replication forks in Escherichia coli. 756 99

This study assessed the value of ultrasonography in characterising bovine cystic ovaries and monitoring their responses to different treatments. Thirteen cows were diagnosed by ultrasonography as having luteinised ovarian cysts and seven were diagnosed as having follicular ovarian cysts. Six of the former were treated with prostaglandin, four with a progesterone intravaginal device (PRID) and three with gonadotrophin-releasing hormone (Gn-RH); five of the latter were treated with Gn-RH and two with a PRID. All the animals were re-examined by ultrasound and blood was collected for the measurement of plasma progesterone concentration at intervals until oestrus. The treatment of the luteinised cysts with prostaglandin caused marked decreases in size and plasma progesterone concentration and altered their echotexture within two to four days; oestrus occurred within three to four days. In two of the cows treated with a PRID the cysts regressed within one to two weeks but the other two cows required supplementary treatment with prostaglandin; oestrus and ovulation were observed only after the cysts collapsed. Gn-RH stimulated oestrus and ovulation within three to four days but the cysts did not collapse until much later. The treatment of the follicular cysts with Gn-RH or a PRID caused fresh ovulation and the formation of a corpus luteum but had little immediate effect upon the cyst. The plasma progesterone concentrations in some of the cows with either follicular or luteal cysts were similar on the day of treatment and were therefore of little value in differentiating the types of cyst.(ABSTRACT TRUNCATED AT 250 WORDS)
Vet Rec 1995 Apr 22
PMID:An ultrasonographic study of bovine cystic ovarian disease and its treatment. 762 56

Sixteen red-necked ostriches (Struthio camelus camelus) were darted under field conditions to immobilise them. Combinations of etorphine hydrochloride with either medetomidine or ketamine were used on 13 birds; xylazine hydrochloride and metomidate alone were used, respectively, on one and two birds. The times to recumbency and recovery were recorded and compared. The principal complications encountered during the anaesthetic procedure were myopathy due to over exertion and respiratory collapse. Etorphine combined with medetomidine led to a sedated state of good quality but short duration, which allowed minor procedures to be carried out.
Vet Rec 1995 Feb 11
PMID:Chemical immobilisation of red-necked ostriches (Struthio camelus) under field conditions. 774 88

One hundred and-two horses requiring to be euthanased for a variety of reasons were killed by the intravenous injection of a mixture of quinalbarbitone sodium (400 mg/ml) and cinchocaine hydrochloride (25 mg/ml). The dose rates used were 1 ml/10, 15, 20 and 30 kg bodyweight, and the time of injection was varied between 5 and 25 seconds. The average time to collapse from the start of the injection was 34 seconds and the average time to clinical death was 230 seconds. Slow injection (particularly of the low dose rates) and premedication with detomidine resulted in a longer time to collapse (median 46 seconds). Premedication with xylazine and low dose rates of the mixture resulted in an unacceptable degree of muscular activity and agonal gasping and death was delayed. Premedication with romifidine and butorphanol resulted in an apparent (but insignificant) reduction in the time to collapse and death but was also accompanied by significant agonal gasping. Without premedication quinalbarbitone and cinchocaine resulted in a smooth and quiet collapse with the cessation of cardiac and respiratory functions within three minutes in all cases, but the palpebral reflex of the horses was prolonged significantly beyond the time when all other reflex activity was lost. Occasional gasping and muscular tremors, particularly of the upper forelimb, occurred particularly when lower dose rates and either very slow or very fast rates of injection were used. One horse which was premedicated with xylazine and received a very low dose at a slow rate showed unacceptably violent muscular activity. At no other time was the procedure regarded as violent or unacceptable.(ABSTRACT TRUNCATED AT 250 WORDS)
Vet Rec 1994 Mar 26
PMID:Humane destruction of horses with a mixture of quinalbarbitone and cinchocaine. 820 6

The history, clinical signs and radiographic and ultrasonographic findings in 16 dogs with pancreatic neoplasia were reviewed retrospectively. Thirteen of the dogs had islet cell carcinoma compatible with insulinoma, one had a pancreatic adenocarcinoma and two had secondary invasion of the pancreas, one by a gastric carcinoma and one by an intestinal lymphoma. The clinical signs in the 13 dogs with insulinoma included collapse in 10 dogs, ataxia in seven, weakness in five, and seizures in two. Two of the 16 dogs had jaundice due to biliary obstruction by the primary tumour or metastases. The sensitivities for pancreatic neoplasia were three of 16 (19 per cent) for radiography and 12 of 16 (75 per cent) for ultrasonography; the sensitivities for metastasis were two of 11 (18 per cent) for radiography and six of 11 (55 per cent) for ultrasonography. Biliary obstruction was detected by ultrasonography in both affected dogs.
Vet Rec 1995 Jul 15
PMID:Ultrasonography of pancreatic neoplasia in the dog: a retrospective review of 16 cases. 853 34

Twenty-seven cases of neosporosis in European dogs are described. The disease was confirmed by immunohistochemistry, electron microscopy, or a favourable response to treatment in the dogs with appropriate clinical signs, and by the presence of antibodies to Neospora caninum but not to Toxoplasma gondii. The affected dogs were two days to seven years old, and of 13 different breeds. Both sexes were affected and in most cases littermates remained normal. Twenty-one cases had an initial hindlimb paresis or ataxia, in which muscle atrophy was the most consistent clinical sign. Rigid hyperextension developed in approximately half of the cases. Anorexia and pyrexia were rare. Other clinical signs included forelimb ataxia, head tremors with tetraparesis and sudden collapse due to myocarditis. Titres of > or = 1:800 in the N caninum indirect fluorescent antibody test were detected in the 20 cases from which serum samples were taken. Such high titres are rare in healthy dogs and strongly suggest a diagnosis of neosporosis. Sixteen of the dogs received appropriate antiprotozoal treatment with clindamycin, potentiated sulphonamides and/or pyrimethamine; 10 made a full or functional recovery. Recovery was less likely in peracute cases with severe clinical signs, and when the treatment was delayed.
Vet Rec 1996 Nov 02
PMID:Clinical aspects of 27 cases of neosporosis in dogs. 893 Dec 99

Information on the morphology of mitochondria during embryogenesis is scattered in the literature but there appears to be a developmental pattern characterized by vesiculation of the mitochondrial cristae. During early organogenesis, the embryo is in a relative state of hypoxia and this is associated with decrease of terminal electron transport system activity and a marked increase in glycolysis. Ultrastructural studies of a 14 somite monkey embryo, and day 10 and 12 rat embryos, along with a review of the literature led us to determine that this hypoxic stage is characterized by vesiculation of the mitochondrial cristae. Starting in the late morula stage and continuing during early postimplantation embryogenesis the cristae increase and appear tubular or vesicular. After the end of neurulation, and with onset of vascular perfusion, the cristae gradually become lamellated and by the limb bud stage appear more mature. We suggest that new cristae form from blebs of the inner mitochondrial membrane and that subsequently with maturation these blebs collapse giving them a lamelliform appearance. The delamellated state of the cristae may protect the embryo from toxic respiratory end-products of oxidative respiration which could accumulate in an embryo lacking vascular perfusion. In the heart of monkey and rat embryos, the mitochondria had diameters which were approximately twice those found in skin and neural tube.
Anat Rec 1998 11
PMID:Ultrastructural study of mitochondria and their cristae in embryonic rats and primate (N. nemistrina). 981 Dec 16

A dog with hydrocephalus as a result of aqueduct stenosis and cerebellar herniation underwent ventriculoperitoneal shunting. Magnetic resonance images and computed tomography scans taken after the surgery revealed subdural accumulations of haemorrhagic fluid and cereberocortical collapse caused by overshunting and leakage of cerebrospinal fluid from the site of insertion of the shunt. However, the degree of cerebellar herniation was reduced after the shunt was inserted, and the dog did not develop any neurological signs and made good progress.
Vet Rec 2005 Feb 12
PMID:Subdural accumulation of fluid in a dog after the insertion of a ventriculoperitoneal shunt. 1574 57

The vascular architecture of the human liver is established at the end of a complex embryological history. The hepatic primordium emerges at the 4th week and is in contact with two major venous systems of the fetal circulation: the vitelline veins and the umbilical veins. The fetal architecture of the afferent venous circulation of the liver is acquired between the 4th and the 6th week. At the end of this process, the portal vein is formed from several distinct segments of the vitelline veins; the portal sinus, deriving from the subhepatic intervitelline anastomosis, connects the umbilical vein, which is the predominant vessel of the fetal liver, to the portal system; the ductus venosus connects the portal sinus to the vena cava inferior. At birth, the umbilical vein and the ductus venosus collapse; the portal vein becomes the only afferent vein of the liver. The efferent venous vessels of the liver derive from the vitelline veins and are formed between the 4th and the 6th week. The hepatic artery forms at the 8th week; intrahepatic arterial branches progressively extend from the central to the peripheral areas of the liver between the 10th and the 15th week. Hepatic sinusoids appear very early, as soon as hepatic cords invade the septum transversum at the 4th week. They then progressively acquire their distinctive structural and functional characters, through a multistage process. Vascular development and differentiation during liver organogenesis is, therefore, a unique process; many of the cellular and molecular mechanisms involved remain poorly understood.
Anat Rec (Hoboken) 2008 Jun
PMID:Vascular development and differentiation during human liver organogenesis. 1848 6

This review briefly summarizes what is known about the dynamic morphology of the hepatic microvascular system that includes all vessels in the liver with a diameter less than 300 microm and various morphological sites within these vessels that regulate the distribution of blood flow. The latter include the various segments of the afferent portal venules and hepatic arterioles, the sinusoids, and central and hepatic venules. Sinusoids are unique exchange vessels lined by fenestrated endothelial cells which have important endocytotic functions and phagocytic Kupffer cells which are important for host defense. These are encircled by extraluminal stellate cells that are specialized pericytes containing fat droplets that store vitamin A. The principle sites for regulating blood flow are in the sinusoidal network with stellate and endothelial cells playing a major role in regulating the diameters of sinusoids and the distribution of blood flow in individual sinusoids, lobules, or segments of lobules. The sinusoidal endothelial cells are a sensitive and early target for several toxicants. For example, as early as 30 minutes after the administration of acetaminophen, the endothelial cells become swollen and begin to lose the ability to endocytose ligands. Within 2 hr, gaps through the cytoplasm appear formed by the destruction and/or coalescence of fenestrae which permit red blood cells to penetrate into the space of Disse. Subsequently, the sinusoid may collapse or disintegrate reducing blood flow.
Anat Rec (Hoboken) 2008 Jun
PMID:The hepatic microvascular system in health and its response to toxicants. 1848 12


<< Previous 1 2 3 4 5 Next >>