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At least 73 records · Page 4Linked to original sources
PubMed1997

Lectin affinity electrophoresis in a yolk sac tumour in the vagina with yolk sac tumour-type glycoform of alpha fetoprotein.

AIMS: To investigate a potential diagnostic use of alpha fetoprotein (alpha FP) isoform analysis by lectin affinity electrophoresis to distinguish between endodermal sinus tumours arising in the vagina in infants from those at other sites. METHODS: alpha FP in the serum of a patient with a vaginal endodermal sinus tumour was analysed for its isoforms by lectin affinity electrophoresis. The isoforms were compared with that of cord serum, sera of hepatoid adenocarcinoma of the uterus, and endodermal sinus tumour of the ovary. RESULTS: The isoforms of alpha FP obtained by lectin affinity electrophoresis in the serum of the patient with vaginal endodermal sinus tumour differed from the isoforms of alpha FP in the cord serum of normal neonates, and sera of patients with hepatoid adenocarcinoma of the uterus or endodermal sinus tumour of the ovary. CONCLUSIONS: Endodermal sinus tumour arising in the vagina could be distinguished from that in the ovary by the lectin affinity electrophoresis, and a potential diagnostic use of alpha FP isoform analysis by the lectin affinity electrophoresis for the detection of the endodermal sinus tumour in infants was demonstrated.

Diagnosis, Differential↗
PubMed2006

The quality and size of yolk sac in early pregnancy loss.

BACKGROUND: Accurate differentiation between normal pregnancy and pregnancy loss in early gestation remains a clinical challenge. AIMS: To determine whether ultrasound findings of yolk sac size and morphology are valuable in relation to pregnancy loss at six to ten weeks gestation. METHODS: Transvaginal ultrasonography was performed in 111 normal singleton pregnancies, 25 anembryonic gestations, and 18 missed abortions. Mean diameters of gestational sac and yolk sac were measured. The relationship between yolk sacs and gestational sacs in normal pregnancies was depicted. The yolk sacs ultrasound findings in cases of pregnancy loss were recorded. RESULTS: In normal pregnancies with embryonic heartbeats, a deformed or an absent yolk sac was never detected. Sequential appearance of yolk sac, embryonic heartbeats and amniotic membrane was essential for normal pregnancy. The largest yolk sac in viable pregnancies was 8.1 mm. Findings in anembryonic gestations included an absent yolk sac, an irregular-shaped yolk sac and a relatively large yolk sac (> 95% upper confidence limits, in 11 cases). In cases of missed abortion with prior existing embryonic heartbeats, abnormal findings included a relatively large, a progressively regressing, a relatively small, and a deformed yolk sac (an irregular-shaped yolk sac, an echogenic spot, or a band). CONCLUSION: A very large yolk sac may exist in normal pregnancy. When embryonic heartbeats exist, the poor quality and early regression of a yolk sac are more specific than the large size of a yolk sac in predicting pregnancy loss. When an embryo is undetectable, a relatively large yolk sac, even of normal shape, may be an indicator of miscarriage.

Abortion, Missed↗
PubMed2006

Filling of the aneurysmal sac with DEAC-glucosamine in an animal model of abdominal aortic aneurysm following stent-graft repair.

AIM: The aim of this study was to present the preliminary results of a technique of abdominal aortic aneurysm (AAA) sac filling in an attempt to obliterate the sac in a swine AAA model, using deacetylated-poly-N-acetyl glucosamine (DEAC-poly-N-acetyl glucosamine). METHODS: Eleven Yucatan pigs, 6 months of age, 40 kg -60 kg, were used to create an AAA with a Dacron pouch implanted surgically and left to mature for 2 weeks. One animal was used to establish the AAA creation procedures. Eight animals were used for AAA sac filling; of the 8 subjects 2 were used for acute studies, and 6 for longer-term studies. Two additional animals were used as controls without polymer sac filling. Two weeks after the AAA creation, a 13 mmx5.5 cm straight tube AneuRx stent-graft was placed to exclude the aneurysm. The aneurysmal sac was filled with a polymer, DEAC-poly-N-acetyl glucosamine at 1.5%, 70% deacetylated, mixed with iohexol. There was filling of a lumbar artery by the polymer in 2 animals. Endpoints were at 1, 2, 4, 6, 12 and 24 weeks, in the chronic study animals and 6 and 12 weeks in the control subjects, procedures consisting of aortography followed by necropsy and pathologic examination. RESULTS: The AAA creation and aneurysm sac filling was successful in all animals. An organized thrombus layer of about 2 mm in thickness was observed in all subjects along the Dacron aneurysm wall. All aneurysms were angiographically patent at the time of treatment, but fresher thrombus within the sac was seen in 4 subjects before the polymer injection. The stent-graft placement excluded the AAA sac and the polymer injection filled all AAA sacs. The AAA sac had acquired a firm rubbery consistency at the time of necropsy. There was mild inflammatory reaction to the Dacron material in the surrounding tissues and within the sac, to a lesser extent. Two animals developed paralysis of the hind limbs following treatment, most likely related to spinal ischemia, and were used as acute subjects. There was no recanalization of the aneurysm sac, during the follow-up time, ranging from 1 to 24 weeks in the treatment or control subjects. There was a 25% shrinkage of the AAA sac at 6th, 40% at 12th week and 75% by the 24th week. The 2 control subjects showed shrinkage of less than 25% at 6 and 12 weeks. There was replacement of the polymer/thrombus complex by connective tissue, fat tissue with capillary neovascularization in the treated subjects. Fibrosis and calcifications were also detected within the sac, mostly around the stent-graft and in contact with the aortic wall starting at 4 weeks. Control subjects did not show replacement of the thrombus by connective tissue or neovascularization. CONCLUSION: The results of this preliminary study support the aneurysm sac filling as a potential tool to exclude the aneurismal sac, promoting shrinkage of the AAA. DEAC -poly-N-acetyl glucosamine promotes clotting within the AAA sac with progressive replacement by connective tissue and neovascularization and may have a potential to prevent endoleaks. The polymer is easy to use, and it seems to have adequate gradual long-term replacement properties, preventing aneurysm sac recanalization.

Angiography↗
PubMed2006

Incidence of unabsorbed yolk sacs in broilers, broiler breeder roosters, white Leghorn hens, and Athens-Canadian randombred control broilers.

Unabsorbed yolk sacs are being investigated as a possible reservoir for internal Campylobacter and salmonellae contamination of processed poultry carcasses. However, it is unknown at what frequency that unabsorbed yolk sacs persist at the time of processing of broilers and spent breeders. Seven sets of 100 broiler carcasses (at 6 or 8 wk of age) were obtained from commercial processing plants. In addition, 100 52-wk-old broiler breeder males, 100 102-wk-old Leghorn hens, and 300 8-wk-old Athens-Canadian randombred control (ACRBC) broilers were euthanized, and their abdominal cavities were opened for determination of the presence of unabsorbed yolk sacs. Carcasses with obliterated yolk stalks or stalks with no detectable yolk material were categorized as normal. Those with unabsorbed yolk sacs were further separated into 2 groups: 1) attached by the yolk stalk to the small intestine or 2) unattached within the abdominal cavity. Yolk sacs were further classified by size: 1) small was <2 mm in diameter, 2) medium was 2 to 10 mm, and 3) large was >10 mm. From the 300 commercial broiler carcasses that were 6 wk old, 54% were categorized as normal with no detectable yolk sac, 35% had an unabsorbed yolk sac attached to the yolk stalk, and 12% had unattached yolk sacs. From the 400 commercial broiler carcasses that were 8 wk old, 49% of the carcasses were normal, 31% had attached unabsorbed yolk sacs, and 20% had unattached yolk sacs. From the 100 rooster carcasses sampled, 73% were normal, 8% had attached unabsorbed yolk sacs, and 19% had unattached yolk sacs. From the 100 White Leghorn hen carcasses sampled, 88% were normal, 8% had attached unabsorbed yolk sacs, and 4% were unattached yolk sacs. From the 300 ACRBC carcasses sampled, 76% were normal, 4% had attached unabsorbed yolk sacs, and 20% were unattached yolk sacs. The incidence of unabsorbed yolk sacs in present day commercial broilers appears twice as high as for mature roosters, hens, or ACRBC broilers.

Animals↗
PubMed1992

[The development of the yolk sac in ruminants (sheep and cattle)].

Yolk sac development was investigated in 69 ovine and 10 bovine embryos from the blastocyst stage to the 7th week of gestation. Light and electron microscopical findings are reported. The yolk sac in sheep and cattle is composed of an enlarged sac-like portion lying below the embryo and two ends which follow the elongated course of the trophoblast. In sheep, an open connection exists between the intestines and the yolk sac up to a crown-rump length (CRL) of 9 mm. It is closed by 12 mm CRL. The wall of the yolk sac is especially well vascularized in the enlarged, sac-like portion. Primary erythropoiesis occurs within the blood capillaries. In the blastocyst, the yolk sac entoderm is made up of elongated, flat cells. It becomes cuboidal in the 3 mm embryo (ovine) and later columnar. The up to 20 microns tall cells stain darkly and contain numerous light-colored vesicles. At 4.5 mm CRL light cells appear between the dark ones. Both cells are rich in rough endoplasmic reticulum (rER). The increased staining of the darker cells is due to an osmophilic cytoplasm and numerous, often parallel lamella of rER. The rER of the light cells is enlarged to irregularly-shaped cisternae, which nearly fill the entire cytoplasm and give them a rounded appearance. The dark cells contain polygonal nuclei, whereas those in the light cells are round with one or two nucleoli. The oval mitochondria have only a few peripheral cristae. Golgi fields are not very common. Cells of the entoderm are connected to one another over zonulae occludentes. They possess microvilli on the luminal surface and are supported by a basement membrane. From 5 mm CRL onwards (ovine), the yolk sac entoderm folds itself between the capillaries, thereby becoming stratified. The intercellular space between the cells expands as projections between neighboring cells interlock. Canaliculi arise between adjacent epithelia. The wall of the yolk sac thickens as a result of this infolding and the densely packed capillaries. Infoldings are especially predominant in the sac-like portion of the yolk sac, and only suggested in the ends. Involution of the yolk sac begins in the peripheral end segments and proceeds centripetally. Numerous glycogen particles appear in the yolk sac entoderm cells of the ovine fetus at a CRL of 36 mm, and by a CRL of 42 mm, the sac-like portion has also begun to show signs of degeneration. Mesenchyme is very sparse within the wall of the yolk sac throughout the entire period of development.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2003

Quantification of cardiac sac network effects on a movement-related parameter of pyloric network output in the lobster.

Cardiac sac network activity (cycle period tens of seconds to minutes) has long been known to alter pyloric network activity (cycle period approximately 1 s), but these effects have not been quantified. Some pyloric muscles extract cardiac sac timed variations in pyloric motor neuron firing, and consequently produce cardiac sac timed movements even though no cardiac sac neurons innervate them. Determining pyloric behavior therefore requires detailed description of cardiac sac effects on pyloric neural output. Pyloric muscle activity correlates well with motor neuron overall spike frequency (OSF, number of spikes per burst divided by cycle period). We therefore quantified the effects of cardiac sac activity on the OSF of all pyloric neurons in the lobster, Panulirus interruptus. The ventricular dilator (VD) neuron had a biphasic response, with its OSF first increasing and then decreasing during cardiac sac bursts. Lateral pyloric (LP) neuron OSF decreased during cardiac sac activity. The pyloric (PY) neurons had two responses, with OSF either decreasing or increasing just after the beginning of cardiac sac activity. The pyloric dilator (PD) neurons had a triphasic response, with OSF increasing slightly at the beginning of cardiac sac activity, decreasing during the cardiac sac burst, and strongly increasing after cardiac sac activity ended. The inferior cardiac (IC) neuron had a biphasic response, with OSF decreasing at the beginning of cardiac sac activity and strongly increasing when cardiac sac activity ceased. These data provide the quantitative description of cardiac sac effects on pyloric activity necessary to predict pyloric movement from pyloric neural output.

Animals↗
PubMed2005

Does sac size matter? Findings based on surgical exploration of excluded abdominal aortic aneurysms.

PURPOSE: To prospectively examine the outcomes of excluded abdominal aortic aneurysms (AAA) that continue to expand without evidence of endoleak. METHODS: From 1984 to 1998, 1218 patients underwent operative retroperitoneal exclusion of AAA and aortoiliac reconstructions. During the procedure, the aneurysm sac was ligated proximally, as well as distally, which created an ideal in-vivo model of excluded AAA sacs with or without endoleaks. From January 2002 to June 2003, 15 of these patients were identified as having an increase in AAA sac size with or without an endoleak on duplex ultrasonography. These patients were prospectively evaluated by computed tomography and diagnostic arteriography. Patients with a demonstrable endoleak underwent embolization, and the remainder underwent open surgical exploration. RESULTS: Eight patients had arteriographically demonstrated endoleaks that were treated with coil embolization. The remaining 7 patients (6 men; mean age 76 years, range 68-81) without a demonstrable endoleak underwent elective surgical exploration and sac endoaneurysmorrhaphy. The mean time interval between the original surgery and aneurysm sac exploration was 76 months (range 52-92); during this time, the mean aneurysm sac size increased by 2.7 cm (range 1.3-5.2). The mean sac pressure was 53 mmHg, and the sac walls were noticeably thickened, with markedly dilated vasa vasorum. The sac contained yellow, fibrinous material with clear serous fluid (5 patients without any evidence of retrograde flow) or liquefied thrombus with serosanguinous fluid (2 patients with retrograde flow from lumbar arteries). No AAA sacs were pulsatile. CONCLUSIONS: Continued expansion of excluded AAA sacs can occur from causes other than a missed endoleak. Exudation of fluid from thickened sac wall and vasa vasorum, as well as local enzymatic activity, might lead to the formation of a sac hygroma. Furthermore, these findings raise questions as to the need for surgical exploration of all patients with an enlarging AAA sac in the setting of low sac pressures and no definable endoleak.

Aged↗
PubMed2001

Aneurysm sac pressure measurements after endovascular repair of abdominal aortic aneurysms.

OBJECTIVES: The goal of endovascular grafting of abdominal aortic aneurysms (AAAs) is to exclude the aneurysm sac from systemic pressure and thereby decrease the risk of rupture. Unlike conventional open surgery, branch vessels in the sac (eg, lumbar artery and inferior mesenteric artery [IMA]) are not ligated and can potentially transmit pressure. The purpose of our investigation was to evaluate the feasibility of various interventional techniques for measuring pressure within the aneurysm sac in patients who had undergone endovascular repair of AAAs. METHODS: Sac pressure measurements were performed in 21 patients who had undergone stent graft repair of AAAs. Seventeen of 21 patients had endoleaks demonstrated on 30-day computed tomographic (CT) scans. Access to the aneurysm sac in these patients was through direct translumbar sac puncture (5 patients), through a patent IMA accessed via the superior mesenteric artery (SMA) (9 patients), or by direct cannulation around attachment sites (3 patients). Four patients had perioperative pressure measurements obtained through catheters positioned along side of the endovascular graft at the time of its deployment. Two of these catheters were left in position for 30 hours during which time CT and conventional angiography were performed. Pressures were determined with standard arterial-line pressure transduction techniques and compared with systemic pressure in each patient. RESULTS: Elevated sac pressure was found in all patients. The sac pressure in patients with endoleaks was found to be systemic (15 patients) or near systemic (2 patients) and all had pulsatile waveforms. Elevated sac pressures were also found in patients without CT or angiographic evidence of endoleak (2 patients). Injection of the sacs in two of these patients revealed a patent lumbar artery and an IMA. CONCLUSIONS: It is possible to measure pressures from within the aneurysm sac in patients with stent grafts with a variety of techniques. Patients may continue to have pressurized AAA sacs despite endovascular AAA repair. Endoleaks transmit pulsatile pressure into the aneurysm sac regardless of the type. It is possible to have systemic sac pressures without evidence of endoleaks on CT or angiography.

Angioplasty, Balloon↗
PubMed1991

Anatomical and functional communications between the synovial sacs of the equine stifle joint.

The anatomical and functional communications of the synovial sacs of the equine stifle joint were evaluated in 50 stifle joints of 25 horses. Femoropatellar joint (FPJ) sacs were injected with 50 ml of gelatin-based dye and horses were then walked for 50 m. Horses were subsequently killed, the stifle joints dissected and the location of the dye recorded. Twenty-three horses (46 joints) had clinically normal stifle joints and in this group, anatomical communications of the stifle joints were bilaterally symmetrical in each horse. In 15 of these 23 horses (65 per cent), direct anatomical communication between the FPJ sac and the medial sac of the femorotibial joint (FTJ) was demonstrated. The FPJ sac communicated with both the medial and lateral sacs of the FTJ in four of these 23 horses (17.5 per cent). There were no anatomical communications between the FPJ sac and either sac of the FTJ in the remaining four horses (17.5 per cent). Functional communication, which was established by finding dye in the FTJ sacs were anatomical communication with the FPJ sac existed, was demonstrated in 14 of 19 horses (74 per cent). Two horses were affected with degenerative joint disease of one stifle joint. In both of these joints the FPJ sac communicated with both the medial and lateral FTJ sacs. This distribution was different from that of the contralateral joint. When performing intra-articular anaesthesia of equine stifle joints, each synovial sac needs to be injected separately to ensure that anaesthesia of the appropriate synovial sac is obtained.

Animals↗
PubMed1992

Can detection of the yolk sac in the first trimester be used to predict the outcome of pregnancy? A prospective sonographic study.

Recent reports have indicated that identification of the yolk sac should precede the detection of the embryo in a normal first-trimester sonographic examination and that failure to visualize a yolk sac strongly suggests an abnormal intrauterine pregnancy. A first-trimester prospective study was performed in 163 normal and 49 abnormal consecutive singleton gestations. All women were examined both abdominally and transvaginally, with pregnancy outcome determined by delivery of a normal infant or a spontaneous abortion. The yolk sac was analyzed in all patients in whom an embryo was not identified (n = 76). When the yolk sac was identified, the following was found: by the abdominal approach with the mean sac diameter (MSD) less than 27 mm (n = 15), nine gestations were normal and six were abnormal, and by the transvaginal approach with the MSD less than 18 mm (n = 13), seven gestations were normal and six were abnormal. The presence of a yolk sac was not consistently predictive of a normal early pregnancy. When the yolk sac was also not identified, the following was found: abdominally with the MSD less than 27 mm (n = 41), 19 gestations were normal and 22 were abnormal, and transvaginally with the MSD less than 18 mm (n = 11), six gestations were normal and five were abnormal. Absence of the yolk sac was not consistently predictive of a spontaneous abortion. When using the MSD range (20-27 mm abdominally and 7-16 mm transvaginally), over which the yolk sac but not the embryo should be identified sonographically, the yolk sac was again not consistently visualized. On abdominal sonograms, the yolk sac was present and absent in three and 10 patients, respectively, for both normal and abnormal pregnancies. On transvaginal sonograms, the yolk sac was present and absent in seven and five normal gestations and in six and four abnormal gestations, respectively. The results of this study suggest that detection of the yolk sac in the first trimester is not an early predictor of pregnancy outcome.

Female↗
PubMed2002

[Comparison of curative effect between decompression and incision of endolymphytic sac].

OBJECTIVE: We compared the curative effect between endolymphytic sac decompression and incision of endolymphytic sac to explore a simple, effective surgical way with less complication. METHOD: 23 endolymphatic sac decompression and 22 incision of endolymphatic sac were performed routinely under general anesthesia. RESULT: 41 of 45 patients were followed up more than 2 years after the surgical procedure, 21 of which received endolymphatic sac decompression, while others received incision of endolymphatic sac. According to Chinese Meniere disease's diagnosis and curative effect standard evaluation criteria tried out in 1996, 13 got grade A(completely controlled), 4 got grade B (fundamentally controlled), 3 got grade C (partially controlled) while 1 got grade D (not controlled) among 21 patients who received endolymphatic sac decompression. The fully control rate is 61.9%. Among 20 patients who received incision of endolymphatic sac, 12 got grade A (completely controlled), 5 got grade B (fundamentally controlled), 2 got grade C (partially controlled) while 1 got grade D (not controlled). The fully control rate is 60%. CONCLUSION: There is no significant difference between endolymphatic sac decompression and incision of endolymphatic sac in curative effect,but endolymphatic sac decompression is more convenient,safe and has less complication compared with incision of endolymphatic sac. From this,we favor endolymphatic sac decompression in selection of surgical method.

Adult↗
PubMed1994

Cadmium-induced rat embryotoxicity in vitro is associated with an increased abundance of E-cadherin protein in the yolk sac.

Cadmium, a cytotoxic heavy metal, is embryotoxic. Cadmium interferes with the functions of other cations such as zinc and calcium. Cadherins, calcium-dependent cell adhesion molecules, are expressed and spatiotemporally regulated in embryos and their yolk sacs during organogenesis. Cadmium has been shown to disrupt calcium-dependent cell-cell interactions and to alter the distribution of epithelial or E-cadherin in cultured cells. The purpose of this study was to determine whether the embryotoxicity of cadmium is mediated through an effect on E-cadherin. Day 10 rat embryos were cultured for 1 hr without cadmium and then cultured for another 2, 6, or 20 hr in the presence or absence of 2.5 microM CdCl2. Embryos and yolk sacs were collected and analyzed separately. The growth of embryos and yolk sacs after exposure to cadmium for 2 or 6 hr was not different from that of controls. After 20 hr exposure to cadmium, embryos were growth retarded, with morphological scores 10-15% lower than those of controls; more dramatically, their yolk sacs were thickened and decreased in diameter to only half of that of control yolk sacs. Northern blot analysis revealed no significant differences in the relative amounts of E-cadherin mRNA between control and cadmium-treated embryos or their yolk sacs. There was also no alteration in the abundance of E-cadherin protein in cadmium-treated embryos at any of the times examined. There was a gradual decline in the relative amount of E-cadherin protein in control yolk sacs with time in culture; interestingly, cadmium treatment appeared to prevent this decline, resulting in significantly higher concentrations of E-cadherin protein in the cadmium-exposed yolk sacs after 6 hr (1.7-fold) or 20 hr (2.3-fold) of culture. The relative abundance of other structural proteins such as alpha- or beta-tubulin and actin was unchanged. Exposure of embryos for 20 hr to concentrations of cadmium varying from nonembryotoxic to embryotoxic resulted in concentration-dependent increases in E-cadherin protein in the yolk sac; E-cadherin was only increased in the yolk sac of growth-retarded embryos. Thus, an increase in yolk sac E-cadherin protein is associated with the induction of embryotoxicity by cadmium. To determine the ability of cadmium to interact directly with the cadherins, the binding of radioactive 109Cd to embryo and yolk sac proteins was assessed. 109Cd bound to an unidentified 87-kDa protein; binding to this protein was attenuated by 1 mM zinc, but not by 1 mM calcium.(ABSTRACT TRUNCATED AT 400 WORDS)

Actins↗