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Biomedical subjects

B Lane

Publications and source records attributed to B Lane.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cost-effectiveness of endovascular therapy in the surgical management of cerebral arteriovenous malformations.

PURPOSE: To determine the economic effect of endovascular therapy in conjunction with surgery for cerebral arteriovenous malformations. METHODS: Twenty-five patients with arteriovenous malformations treated with embolization and surgical excision or embolization alone were compared with reported results in 475 patients who underwent surgery only. Respective mean morbidity and mortality rates were calculated and a cost-effectiveness analysis was performed in terms of costs of hospitalization, professional fees, and other direct procedural and indirect costs. Quality-adjusted life-years saved were also calculated. RESULTS: The net effective treatment cost per cure was $71 366 (in 1992 dollars) for embolization and surgery compared with $78 506 for surgery alone. This resulted in a 9% average savings per treated patient. Cost per quality-adjusted life-year calculations resulted in a cost of $6734 for embolization and surgery and $9814 for surgical treatment alone, with savings as high as 34% when endovascular therapy was used. CONCLUSION: Endovascular therapy in conjunction with surgery resulted in significant economic benefits for treatment of cerebral arteriovenous malformations.

Adult↗
PubMed1995

Brain dysmorphology in adults with congenital rubella plus schizophrenialike symptoms.

Brain morphology was quantified with magnetic resonance imaging (MRI) in adult patients with congenital rubella who also had schizophrenialike symptoms. MRIs were compared with those of adult early-onset schizophrenic patients without congenital rubella and age-matched healthy control subjects. The rubella patients had significantly smaller intracranial volumes and shorter stature than the schizophrenic patients or the controls; however, both patient groups had smaller cortical gray matter, but not white matter, volumes than the control group, even when the MRI volumes were corrected for head size and age. In addition, both patient groups showed significant enlargement of the lateral ventricles but not cortical sulci when compared with expected values of normal adults of the same age and head size. Overall, the pattern of dysmorphology was identical in the rubella and the schizophrenic groups. The observations in the rubella group are consistent with a developmental lesion that limits full brain growth, with the small intracranial volume due at least in part to a severe cortical gray matter volume deficit. Thus, the brain dysmorphology of congenital rubella may provide an instance of prenatal viral infection that models the schizophrenic pattern and provides indirect support for a developmental hypothesis of the neuropathogenesis of schizophrenia.

Adult↗
PubMed1995

Comparison of serologic analysis and in situ localization of PCR-amplified cDNA for the diagnosis of hepatitis C infection.

The purpose of this study was to compare the serological analysis for hepatitis C infection using the recombinant immunoblot assay (RIBA) to the direct in situ localization of the hepatitis C viral genome using the reverse transcriptase (RT) in situ PCR technique. Concurrent sera and liver biopsies from 42 patients with clinical and histologic evidence of chronic liver disease were studied. Antibodies against hepatitis C specific antigens were demonstrated by RIBA in the sera of 39/42 (92%), and PCR amplified viral cDNA was detected in the biopsies of 21 (54%) of the 39 seropositive patients. The detection rate using standard in situ hybridization for the tissues known to be viral positive with RT in situ PCR was 9/21 (42%). It is concluded that approximately one-half of patients with chronic hepatitis and serologic evidence of hepatitis C infection will not have virus detectable in their liver biopsy even with a highly sensitive PCR-based technique.

Hepatitis C↗
PubMed1995

Combined use of endovascular coils and surgical clipping for intracranial aneurysms.

We report two cases in which combined surgical clipping and endovascular coils have been used to treat intracranial aneurysms. In one case, a 59-year-old woman with multiple episodes of subarachnoid hemorrhage had an anterior communicating artery aneurysm, which was initially treated with coils and then clipped to occlude the aneurysm securely. In the second case, a broad-based cavernous aneurysm could not be completely surgically occluded, but surgical clipping did decrease the aneurysm neck size, allowing it to be successfully treated with coils.

Adult↗
PubMed1994

Decidualization of human endometrial stromal cells in vitro: effects of progestin and relaxin on the ultrastructure and production of decidual secretory proteins.

Decidual cells arise by proliferation and differentiation of endometrial stromal cells of the uterus after appropriate stimulation by ovarian hormones. Previously we have shown that progestin and relaxin stimulate the secretion of several decidual-cell-specific secretory proteins in a long-term primary cell culture system. We now report the effects of progestin and relaxin on the morphology of stromal cells in association with the production rate of two major decidual secretory proteins, prolactin and insulin-like growth factor binding protein-1 (IGFBP-1). Stromal cells were cultured in RPMI 1640 and 2% fetal bovine serum for 22 days under control conditions (no hormone), with relaxin or medroxyprogesterone acetate (MPA), or MPA plus relaxin. Cells treated with MPA alone or MPA plus porcine relaxin grew to a high density with many areas of heaping while control cells and cells grown in medium containing relaxin alone formed discontinuous layers. The cytoplasm was distinguished by aggregates of rough endoplasmic reticulum and secretory granules. Surfaces of cells treated with MPA plus relaxin had clusters of short blunt processes containing secretory granules. The processes were rarely seen in cells exposed to MPA alone and completely absent in control cells or cells exposed to relaxin alone. Intercellular space was greatly widened in cells treated with MPA alone or MPA plus relaxin. There were many extended gap junctions in MPA- and relaxin-treated cells in contrast to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Neuroradiology.

Explore the source record for details and available documents.

Central Nervous System Diseases↗
PubMed1994

Stent placement for arterial and venous cerebrovascular disease: preliminary experience.

PURPOSE: To report initial clinical experience with stent placement in the cerebrovascular circulation. MATERIALS AND METHODS: Four patients underwent arterial or venous stent placement. Two patients had cervical internal carotid artery dissections, with aneurysms and stenoses of the distal cervical carotid artery. Two patients had venous occlusive disease involving the major dural sinuses, with substantial pressure gradients across the stenoses. RESULTS: Immediately after stent placement, the true arterial lumina returned to normal diameter and both carotid aneurysms were more than 90% occluded. Follow-up angiography demonstrated continued improvement in the arterial aneurysms. Both patients with dural sinus venous occlusive disease showed substantial improvement of the sinus stenoses and substantial reversal of the pressure gradients after venous stent placement. At follow-up, these patients have done well. CONCLUSION: This preliminary experience suggests there may be a role for stents in the management of arterial and venous cerebrovascular disease, including carotid artery dissection and venous occlusive disease.

Adult↗
PubMed1994

Correlation of pressure measurements with angiographic characteristics predisposing to hemorrhage and steal in cerebral arteriovenous malformations.

PURPOSE: To determine whether there is a physiologic explanation for the predisposition of patients with certain angiographic characteristics to symptoms of hemorrhage and steal. METHODS: Superselective transcatheter feeding arterial pressure and mean arterial pressure measurements were obtained before embolotherapy in 32 patients with cerebral arteriovenous malformations. Pressures were correlated with previously described angioarchitectural characteristics predisposing to hemorrhage and steal. These included size of the arteriovenous malformation, feeding artery length, venous drainage pattern, and angiomatous change. RESULTS: The feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios were significantly decreased in patients with angiomatous change. Feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios progressively decreased as lesions went from peripheral, to mixed, to central venous drainage. A trend for lower feeding arterial pressure was also demonstrated with greater feeding pedicle length. A statistically significant correlation could not be demonstrated between feeding arterial pressure or feeding arterial pressure/mean arterial pressure ratios and size of the arteriovenous malformation, hemorrhage, or symptoms of steal. CONCLUSIONS: Feeding arterial pressure measurements help provide a physiologic basis for the relationship between certain angiographic characteristics and hemorrhage and steal symptoms in patients with arteriovenous malformation.

Adolescent↗
PubMed1994

A mechanically detachable coil for the treatment of aneurysms and occlusion of blood vessels.

PURPOSE: To evaluate mechanically detachable coil designs capable of controlled and instantaneous release within an aneurysm or vascular space. METHODS: Three mechanically detachable coil designs, clamped ball, looped ribbon, and interlocking cylinder, were evaluated using in vitro and in vivo testing to study reliability of coil release, retractability, and coil behavior in a microcatheters. In vitro tests were performed using a glass side-wall aneurysm model and conventional microcatheters. In vivo experiments in rabbits included aneurysm models (side-wall and bifurcation) and arterial occlusions (carotid and renal). RESULTS: All three designs deployed coils easily and were able to retract coils after partial deployment. Motion was seen in previously released coils and in the catheter when using the clamped ball and looped ribbon designs. The interlocking cylinder design did not cause similar motion. When compared with the other two designs, the interlocking cylinder had significantly greater separation forces between coil pusher and coil while in the catheter. Frictional forces within the catheter were lower for the interlocking cylinder mechanically detachable coil design than for a commercially available conventional coil and coil pusher system. During in vivo testing, the mechanically detachable coil design operated smoothly in the catheter, providing good release and retraction in aneurysms and straight vessels. CONCLUSION: The interlocking cylinder mechanically detachable coil design is superior to the other two tested designs. The mechanically detachable coil was reliably delivered and detached in in vivo testing for the treatment of aneurysms and for the occlusion of blood vessels.

Animals↗
PubMed1993

Selective cholangiography in laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is now the method of choice for removing the diseased gallbladder. Asymptomatic common bile duct stones occur in approximately 6 per cent of patients. Controversy exists, however, as to whether selective or routine peroperative cholangiography should be performed during laparoscopic cholecystectomy. Over a 21-month period 300 consecutive laparoscopic cholecystectomies without routine cholangiography were attempted. There were 28 conversions. In all, 229 patients did not undergo cholangiography and in this group there were two common duct injuries. These were both identified and dealt with by open operation. Five patients underwent peroperative cholangiography, none of whom was found to have common duct pathology. Endoscopic retrograde cholangiopancreatography was performed in 38 patients. Of 27 who had this investigation performed before operation, common duct stones were diagnosed in seven (26 per cent). Two common duct stones were discovered in 11 patients who underwent the investigation after operation. Thus only two of 240 patients (0.8 per cent) who did not undergo preoperative or peroperative cholangiography subsequently had symptomatic duct stones. Peroperative cholangiography may be indicated in selected patients who have had symptoms of common bile duct stones or in those in whom the biliary anatomy is unclear. However, routine preoperative or peroperative cholangiography is unnecessary during laparoscopic cholecystectomy.

Adolescent↗
PubMed1993

FKBP12-FK506 complex inhibits phosphatase activity of two mammalian isoforms of calcineurin irrespective of their substrates or activation mechanisms.

The interaction of calcineurin (Ca2+/calmodulin-dependent protein phosphatase) with the potent immunosuppressive agent FK506 and its 12 kDa isoform binding protein (FKBP12) was investigated. The FKBP12-FK506 complex inhibited the Ca2+/calmodulin-stimulated phosphatase activity of each of two calcineurin isoforms, which contain either the catalytic subunit A alpha or A beta (calcineurin A alpha or A beta) of bovine calcineurin. Calcineurin phosphatase activity was inhibited by the FKBP12-FK506 complex irrespective of the substrate or the enzyme activation mechanism. FK506 and FKBP-12 inhibited calcineurin in a concentration-dependent manner, and complete inhibition of the phosphatase activity appeared to require a molar excess of FKBP12-FK506 complex. Immunochemical measurements revealed tissue differences in the concentration of calcineurin, which may be of importance to the selectivity for immunosuppression of all of the biological effects. Direct binding studies with [3H]dihydro-FK506 suggest that the ratio of FKBP12-FK506 complex to calcineurin in vivo when IL2 production is inhibited is well correlated with the ratio when calcineurin phosphatase activity is inhibited in vitro. These results suggest that calcineurin is a relevant cellular target of FK506 when bound to FKBP-12.

Amino Acid Sequence↗
PubMed1993

Intracellular localization of polymerase chain reaction (PCR)-amplified hepatitis C cDNA.

The cellular distribution of hepatitis C virus was examined in formalin-fixed, paraffin-embedded tissues by in situ localization of the polymerase chain reaction (PCR)-amplified viral cDNA. Of nine liver biopsies studied, five were from patients seropositive for hepatitis C, one was from a seronegative patient who had detectable hepatitis C cDNA by standard reverse transcriptase (RT) PCR, and the remaining three were from patients without evidence of hepatitis C infection. Sequences homologous to viral RNA were rarely identified in the hepatitis C cases by standard RNA-cDNA in situ hybridization, but PCR-amplified viral cDNA was detectable in many hepatocytes in a panlobular distribution and in scattered Kupffer cells in each of the six hepatitis C cases and none of the controls. The pattern was equivalent whether intracellular localization was done by in situ hybridization after the RT and PCR steps or if digoxigenin-labeled nucleotide was incorporated into the amplified product. No signal was evident in the positive biopsies if the RT step was omitted, if "nonsense" primers were used, or if RT in situ PCR was preceded by RNase digestion. The RT in situ PCR technique allows for the rapid detection of any RNA virus, even if it is present in low copy number, and permits direct morphological correlation.

Base Sequence↗
PubMed1993

Nuclei that lack a lamina accumulate karyophilic proteins and assemble a nuclear matrix.

Xenopus egg extracts, which support nuclear assembly and DNA replication in vitro, were physically depleted of lamin B3 using monoclonal antibodies linked to magnetic beads. Depleted extracts were still able to support nuclear envelope assembly around demembranated sperm heads but the resulting pronuclei lacked a lamina and were unable to initiate semiconservative DNA replication or to assemble replicases, confirming previous data. Immunoblotting analysis of isolated nuclei and nuclear matrix fractions indicated that lamin-depleted nuclei still accumulated nucleoporins and PCNA. Furthermore, the rate of PCNA uptake was identical in lamin-depleted and control nuclei. However, neither the nucleoporins nor the PCNA was associated with nuclear matrix fractions. The major protein components of sperm pronuclear matrix fractions were characterized by two-dimensional gel electrophoresis. Of these proteins only three out of 22 species, other than the lamins, were significantly reduced in lamin-depleted nuclei, indicating that these nuclei do assemble a nuclear matrix.

Animals↗