In vivo quantification of T₂ anisotropy in white matter fibers in marmoset monkeys

T₂^?-weighted MRI at high field is a promising approach for studying noninvasively the tissue structure and composition of the brain. However, the biophysical origin of T₂^? contrast, especially in white matter, remains poorly understood. Recent work has shown that R₂^? (= 1/T₂^?) may depend on the tissue's orientation relative to the static magnetic field (B₀) and suggested that this dependence could be attributed to local anisotropy in the magnetic properties of brain tissue. In the present work, we analyzed high-resolution, multi-gradient-echo images of in vivo marmoset brains at 7 T, and compared them with ex vivo diffusion tensor images, to show that R₂^? relaxation in white matter is highly sensitive to the fiber orientation relative to the main field. We directly demonstrate this orientation dependence by performing in vivo multi-gradient-echo experiments in two orthogonal brain positions, uncovering a nearly 50% change in the R₂^? relaxation rate constant of the optic radiations. We attribute this substantial R₂^? anisotropy to local subvoxel susceptibility effects arising from the highly ordered and anisotropic structure of the myelin sheath.     

Supersonic shear wave elastography of in vivo pig kidney: influence of blood pressure, urinary pressure and tissue anisotropy

The in vivo influence of renal anisotropy and of urinary and vascular pressure on elasticity values using ultrasonic supersonic shear wave elastography was studied in pigs. Experiments were conducted in agreement with the European Commission guidelines and directives of the French Research Ministry. Six kidneys in three pigs were studied in vivo. Elasticity of renal cortex and medulla was quantified through the shear modulus (μ) by using the supersonic shear imaging technique with an 8 MHz linear ultrasound probe. All measurements were done peroperatively both in the axis and perpendicular to the main axis of pyramids, in normal condition, after progressive increase of urinary pressure, and after renal artery and renal vein ligation. In normal conditions, cortical (C) and medullary (M) elasticity values were always higher when acquisitions were realized with the ultrasound main axis perpendicular to main pyramid axis (C_//: 7.7 ± 2.3 kPa; M_//: 8.7 ± 2.5 kPa) than parallel (C_⊥: 6.9 ± 1.4 kPa; M_⊥: 6.6 ± 2.3 kPa), demonstrating an effect of renal anisotropy. In renal cortex, two bands were separated, inner cortex showing higher elasticity values (IC_⊥: 8.1 ± 1.9 kPa) than outer cortex (OC_⊥: 6.9 ± 1.4 kPa). Renal artery and renal vein ligation induced a decrease and an increase of elasticity respectively. Parenchymal elasticity increased linearly with elevation of urinary pressure. Intrarenal elasticity values vary with tissue anisotropy and, with vascular and urinary pressure levels. These parameters have to be taken into account for interpretation of tissue changes. Separation of outer and inner cortex could be attributable to perfusion differences.     

Episodic memory of APOE ε4 carriers is correlated with fractional anisotropy, but not cortical thickness, in the medial temporal lobe

The ε4 allele of apolipoprotein E (apoE, protein; APOE, gene) is the most important genetic risk factor for the development of Alzheimer's disease (AD). Cortical structures in the medial temporal lobe (MTL) are important for memory function and are affected early in AD. Both gray matter (GM) and white matter (WM) structures in the MTL have been reported to display AD related changes in healthy APOE ε4 carriers, but the effects are relatively small and somewhat deviating. Still, there is a lack of studies directly linking structural measures with performance on psychometric tests in ε4+ individuals. We hypothesized that intact WM integrity in the MTL facilitates episodic memory, and predicted a higher correlation between WM integrity and memory performance in APOE ε4 carriers due to a possible limiting effect of WM microstructure. In the present study of 92 healthy (MMSE>27) participants we acquired T1 3D and DTI images from a 1.5T MRI scanner, and tested the participants with California Verbal Learning Test II (CVLT-II). The study had two main aims: 1) to relate verbal memory performance to entorhinal WM (EWM) integrity in APOE ε4 carriers and non-carriers, and 2) to investigate APOE ε4 effects on EWM and EC thickness. We observed a strong, positive correlation between FA in the EWM and memory performance, which was driven solely by APOE ε4 carriers. These effects were significant while controlling for age, sex, EWM volume and EC thickness. Although EC thickness was significantly reduced in ε4 carriers, we did not find a relationship between EC thickness and memory performance. Thus, increased susceptibility of the WM structures underpinning the entorhinal-hippocampal network, offers a plausible explanation for the earlier onset of cognitive decline previously reported in APOE ε4 carriers.     

Postoperative rehabilitation of senile fracture of neck of femur

Background:Thesenliewithfracturerestinbedforalongtime,andhaven'tsufficientfunctionexercise,allabovewillleadtoosteoporosis,badrepairofbonetissue,muscleatrophyandjointstiffnessoccurs,whichbringsufferingandenconomicburden.Objective:Tosummarizetheeffectofpostoperativefunctionexercisesonrecoveryoffractureofneckoffemur.Unit:OrthopedicsHospitalofShenyang.Subjects:Therewere86patientsoffractureofneckoffemur,including52males,34famles,aged60-84years,average72years.Accordingtopositionoffractureline:sub…     

Analysis of rehabilitation treatment of slippage of lumbar vertebrae

INTRODUCTIONSlippageoflumbarvertebraeisasecondcommondiseaseafterprotrusionofintervertebraldiscs.Althoughsomepatientswerecuredbyconservativetherapy,surgicaltreatmentisneededinsomecases犤1犦.FromMarch1994toMarch2001,weusedstealplateinternalfixationtotreat18casesofslippageandtheeffectwasobvious.Thefollowingisthereport.MATERIALSANDMETHODSMaterial18patientswereinvolvedincluding10malesand8femalesaged41-64(mean:46)years.Slippagelocus:L4-5,11cases;L5-S1,7cases.Clinicalmanifestation:all…     

Series of spinal balance therapy in treatment of 196 cases of protrusion of intervertebraldisc

Background：Protrusionofintervertebraldiscwasaclinicalsyndromresultedfromintervertevraldiscdegeneration，fibrousringrupture，protrusionofpulpiformnucleusthatstimulateandcom－pressesnerveroot，andcomprehensiveconservativetherapywasoftenadopted．Inthisgroupofdata，１９６casesofprotrusionofinterverte－braldisctreatedbyseriesofspinalbalancetherapywerecollectedfromJanuary２０００toDecember２００１．Objective：Toinvestigateeffectofseriesofspinalbalancetherapyintreatmentofprotrusionofintervertebrald…     

Appliance of Tenor system in treatment of fissural olisthe of isthmus of lumbar vertebra

BACKGROUND: Application of Tenor system and is to decompress nerve root, reduction of olisthe, internal fixation and auto-grafts are to restore anatomic structure and stability of spinal column.OBJECTIVE: To observe therapeutic effects of Tenor system on fissural olisthe of isthmus of lumbar vertebra.UNIT: Department of Orthopaedics, General Hospital of Armed Police     

The rehabilitation treatment of senile fracture of neck of femur

BACKGROUND: Despite of treatment of operation or routine conservation, special psychological and physical characteristics, osteoporosis, recession of muscular strength and long braked time on bed often cause retrograde degeneration of muscle and skeleton and the complications of delayed recovery and other diseases. To above problems, a series of continuous ways of functional rehabilitation are applied and satisfactory effects are achieved.     

Experience of prevention and treatment of deep burn of hand

INTRODUCTIONHowtopreventhanddeformitycausedbyburn,restoreappearanceandworkingabilityhasbeenalwaysthemainproblem,thefollow-ingisthereportaboutcausesofdeformityandexperienceofpre-ventionandtreatment.GENERALDATA2037casesofburntreatedfromJanuary1997toOctober2002amongincluding957casesofburnofhandsandtheincidencewas46.9%amongwhichwere229casesofdeepburnand195pa-tientsreceivedearlysurgicaltreatment.6patients(15fingers)un-derwentfingeramputation.38casesneededplasticsbecauseofscardeformityinlat…     

Promoting effect of limb functional exercises on recovery of senile fracture of neck of femur

BACKGROUND：Senilefractureofneckoffemurneedsalong－termrecoveryoutofhospitalevenafterclinicalcure，soclinicalnursingandrehabilitationinstructionareveryimportant．OBJECTIVE：Toobservetheeffectsoflimbfunctionalexer－cisesonsenilefractureofneckoffemur．UNIT：SecondDepartmentofSurgery，People＇sHospitalofFeichengSUBJECTS：２９patientswereinvestigatedfrom１９９９to２００１inourdepartmentincluding１２malesand１７femaleswith１５pa－tientsaged７０－７９yearsoldand１４patientsaged８０－８…     

Analysis of difficulty of urination following transurethral electrovaporisation of the prostate

INTRODUCTIONDifficultyofurinationiscommonaftertransurethralelectrovaporisationoftheprostate(TuVP),whichinflictspatientsphysiologicallyandpsychologically.MATERIALSANDMETHODS78patientswithbenignprostatehyperplasiareceivedourtreatmentafterTuVpduring2000and2001.Thesepatientswereof62-84yearsold,withmeanageof72.3.Thefollowupvariedbetween1-2years,averagely1.4years.8casesdevelopeddifficultyinurination,andtheinvolvedcausesweredefinedbyusingfiberscopeofbladderandurethra.Treatmentwascarrie…     

Investigation of features of hemostasis sponge of collagen and chitosan compound

AIM：To investigate the hemostasis effect of hemostasis sponge of collagen and chitosan compound invitro and in vivo.METHODS:The hemostasis sponge of collagen and chitosan compound was made by mixing collegen I extracted by enzymelytic methods and crosslinked by glutaric dialdeiyde and then lyophilized.The New zealand rabbit were created with a 1cm&;#215;1cm wound in the center artery of the ear.The center artery of the ear were transected and record the hemostasis time since pressured with hemostasis sponge of collagen and chitosan compound and obsevve its effects.In other experiements,1cm&;#215;1cm bleeding wound were established in the liver of the rabbit.Then pressured with hemostasis sponge of collagen and chitosan compound on the wounds and record the hemostasis time;The four corner of the hemostasis sponge of collagen and chitosan compound were sutured to investigate the absorption situation with the control of gelatin treated with same procedures.RESULTS:The bleeding time using hemostasis sponge of collagen and chitosan compound was 120 seconds compared with 600 seconds of using gelatin,and the hemostasis time using hemostasis sponge of collagen and chitosan compound was 40 weconds compared with 75 seconds of using gelatin.Both the hemostasis sponge of collagen and chitosan compound and gelatin can be degradated within 5 months.CONCLUSION:Hemostasis effect of hemostasis sponge of collagen and chitosan compound is better than that of gelatin and it has an promising future in surgery.     

Effect of hyperbaric oxygen on healing of chronic ulcer of skin

INTRODUCTIONAtpresent,treatmentofchroniculcerofskininclinicisverydifficult.Effectofcomprehensivetreatmentbyhyperbaricoxygenonchroniculcerisobvious.MATERIALSANDMETHODSMaterials80patientstreatedbyhyperbaricoxygeninourhospitalfromFebruary1987toDecember2000wereinvestigatedincluding59malesand21femalesaged17-72(mean:40)yearswithdiseascourse,1monthto30years.Ulcerareawas1-13cm2andulcelocatedatleftlowerlimb,21cases;bothlimbs,15cases;sacraportion,19cases.Causes:Varicosisoflowerlimbs,23case…