Predictive Value of the GLIM Criteria in Chinese Community-Dwelling and Institutionalized Older Adults Aged 70 Years and Over.

OBJECTIVES: The Global Leadership Initiative on Malnutrition (GLIM) has recently published criteria for classifying malnutrition. This study investigated the associations between malnutrition and adverse outcomes, and identified which component(s) of the GLIM criteria is/are risk factor(s) of adverse outcomes in Chinese older adults. DESIGN: A prospective cohort study of Chinese older adults in a healthy ageing study. SETTING: Participants' place of residence. PARTICIPANTS: Community-dwelling and institutionalized Chinese older adults aged ≥70 years living in Hong Kong. MEASUREMENTS: Malnutrition at baseline was classified according to selected GLIM criteria. Adverse outcomes including poor self-rated health, functional limitation (Barthel Index), falls, frailty (FRAIL scale), hospitalization and mortality were assessed after a 3-year follow-up. Associations between malnutrition and components of selected GLIM criteria (weight loss, low body mass index (BMI), low muscle mass and disease burden) and each adverse outcome were examined using adjusted binary logistic regression and Cox proportional hazards model. Odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI) are presented. RESULTS: Data of 1576 community-dwelling (45.5% female, 78.1±6.5 years) and 427 institutionalized (69.6% female, 85.5±6.4 years) older adults were included at baseline. Among community-dwelling older adults, malnutrition was associated with frailty (n=899, OR: 2.44, 95% CI: 1.05-5.70) and mortality (n=1007, HR: 1.37, 95% CI: 1.12-1.66). No association was found for other outcomes. Among institutionalized older adults, malnutrition was not associated with any outcomes. Low BMI and low muscle mass were risk factors of frailty; while weight loss was a risk factor of mortality in community-dwelling older adults. Weight loss and disease burden were risk factors of mortality among institutionalized older adults. CONCLUSION: The association between malnutrition and frailty and mortality was observed in community but not in institutional settings. Further studies are required to draw more definitive conclusions on the use of GLIM criteria in institutional settings.

Entrapment of the sciatic nerve following closed reduction of a dislocated revision total hip replacement.

Injury to the sciatic nerve following closed manipulation of a dislocated total hip replacement is rare. We present such a case in an elderly patient with partial recovery following exploration and release of the nerve.

Kinetics of immune cell migration at the human ocular surface.

AIM: The conjunctiva has a resident population of intraepithelial and stromal immune cells. These cells play an active part in ocular surface defence and disease. Our aim was to study the migration of immune cells in the human conjunctiva, across the basement membrane and to characterize their phenotypes. METHODS: Organ cultures of human conjunctival samples, denuded of the epithelium, were maintained for varying time periods. Cells migrating on to the surface were harvested and analysed by flow cytometry. Conjunctival samples were also studied by immunohistology and electron microscopy. RESULTS: A preferential unidirectional migration of immune cells from the stroma, through pores in the basement membrane, towards the surface was noted. Cells migrated through intrastromal channels, communicating with the surface basement membrane pores. CD3+ T cells (76.18%) were the predominant migrating phenotype. The ratio of CD4:CD8 T cells was approximately 4:1 as compared with the control conjunctiva where the ratio was approximately 2:1. Various other phenotypes including NK, NKT and B cells were also detected. Only 8.41% of the migrating population expressed the Human mucosal lymphocyte-1 marker of intraepithelial lymphocytes. CONCLUSIONS: Immune cells migration at the ocular surface is an active process involving the formation of intrastromal channels, and cell egression through intact basement membrane pores. The preferential migration of CD4 T cells indicates that this is a specific response of conjunctival lymphoid tissue and not a passive movement of cells. A wide range of immune cell phenotypes exist at the ocular surface. This model can serve to test in vitro the effects of injurious agents on the ocular surface.

3D time of flight MR angiography: acquisition with small field of view and low phase encodes.

The aim of the study was to evaluate and compare the image quality of the 3D TOF MRA acquired with a small FOV and low phase encodes with those MR angiographic images acquired with standard pulse sequence parameters. Twenty patients who were referred to our institution for MR imaging of the brain and strictly satisfied the selection criteria were included in this study. Apart from the routine protocol for MR imaging of the brain, 3D TOF MRA of the circle of Willis with a small FOV and a standard FOV were performed. The image quality of all MRA was evaluated by two independent observers who were blind to the pulse sequence parameters. From the standard FOV MRA, 22.5, 12.5, and 5% of the patients were graded as mild, moderate, and severe stenosis of the internal carotid artery, respectively. On the contrary, no apparent stenosis was observed from the small FOV MRA with low phase encodes. Regarding the reduction in MR artifacts and acquisition time achieved with the small FOV 3D TOF MRA with low phase encodes, this might be a useful MR angiographic technique to be used in routine clinical practice.

Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging.

Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury.

Syphilitic myelitis with diffuse spinal cord abnormality on MR imaging.

Syphilitic myelitis is a very rare manifestation of neurosyphilis. The MRI appearance of syphilitic myelitis is not well documented and only a few cases have been reported. We present a 52-year-old woman with acute onset of paraplegia. Magnetic resonance imaging of the spine showed diffuse high signal intensity in the whole spinal cord on T2-weighted images. Focal enhancement was observed in the dorsal aspect of the thoracic cord on T1-weighted gadolinium-enhanced images. To our knowledge, diffuse spinal cord abnormality in syphilitic myelitis has not been reported in the international literature. Disappearance of the diffuse high-signal lesions with residual focal enhancement was noted after antibiotic therapy. The patient suffered significant neurological deficit despite improvement in the MR images. In this article we present the imaging findings and review the literature of this rare condition.

Tumefactive demyelinating lesions by combined perfusion-weighted and diffusion weighted imaging.

Tumefactive demyelinating lesion may sometimes mimic intracranial neoplasm or abscess and pose a diagnostic problem both clinically and radiologically. The diagnosis is even more complicated since multiple sclerosis is relatively uncommon among Chinese and due to low incidence of oligoclonal protein in the cerebrospinal fluid. We present a Chinese lady with tumefactive demyelinating lesion, which mimic cystic neoplasm and cerebral abscess. The use of perfusion and diffusion weighted imaging obviated unnecessary surgical biopsy.

Evaluation of cerebral abscesses by diffusion-weighted MR imaging and MR spectroscopy.

Cerebral abscess may sometimes mimic necrotic tumor and cystic metastases both clinically and radiologically. The imaging findings may be indistinguishable on conventional magnetic resonance imaging. Although recent studies have shown that cerebral abscess displays restricted diffusion on diffusion-weighted imaging (DWI), it is not pathognomic. Necrotic tumor and cystic metastases may occasionally have restricted diffusion on DWI. Since the urgency of surgical intervention and approach of surgery is different, MR Spectroscopy may be used in conjunction with DWI in establishing the correct diagnosis.

Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage.

The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images ( p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain.

Acute vertebral body compression fractures: discrimination between benign and malignant causes using apparent diffusion coefficients.

Diffusion weighted MRI was performed on patients with acute vertebral body compression. The usefulness of the apparent diffusion coefficient (ADC) in differentiating between benign and malignant fractures was evaluated. A total of 49 acute vertebral body compression fractures were found in 32 patients. 25 fractures in 18 patients were due to osteoporosis, 18 fractures in 12 patients were histologically proven to be due to malignancy, and 6 fractures in 2 patients were due to tuberculosis. Signal intensities on T(1) weighted, short tau inversion recovery (STIR) and diffusion weighted images were compared. ADC values of normal and abnormal vertebral bodies were calculated. Except for two patients with sclerotic metastases, benign acute vertebral fractures were hypointense and malignant acute vertebral fractures were hyperintense with respect to normal bone marrow on diffusion weighted images. Mean combined ADCs (ADC(cmb); average of the combined ADCs in the x, y and z diffusion directions) were 0.23 x 10(-3) mm(2) s(-1) in normal vertebrae, 0.82 x 10(-3) mm(2) s(-1) in malignant acute vertebral fractures and 1.94 x 10(-3) mm(2) s(-1) in benign acute vertebral fractures. The differences between ADC(cmb) values were statistically significant (p<0.001). The ADC is useful in differentiating benign from malignant acute vertebral body compression fractures, but there may be overlapping ADC values between malignant fractures and tuberculous spondylitis.

Discrimination of an infected brain tumor from a cerebral abscess by combined MR perfusion and diffusion imaging.

The aim of this study was to investigate the signal characteristics of the abscess wall and tumor wall on diffusion-weighted and perfusion-weighted images and thus to evaluate the feasibility of using combined MR diffusion and perfusion imaging to differentiate pyogenic cerebral abscess from infected brain tumor. The tumor wall of various types of cystic or necrotic brain tumor was significantly hyperintense relative to that of cerebral abscess wall on both diffusion-weighted images and regional cerebral blood volume maps. Sixteen patients who had cerebral masses with large cystic or necrotic cavities were imaged to generate diffusion-weighted images and regional cerebral blood volume maps using single-shot echoplanar imaging (EPI) pulse sequences. Apart from qualitative analysis, apparent diffusion coefficients (ADC) as well as regional cerebral blood volume (rCBV) ratios were calculated from the abscess wall and peripheral tumor wall and comparison was made by using Student's t-test. The tumor wall of various types of cystic or necrotic brain tumor had significantly lower ADCs relative to those of the abscess wall (P<0.005) and thus appeared relatively hyperintense on diffusion-weighted images. The mean rCBV ratio relative to normal white matter (2.90+/-0.62) of the peripheral tumor wall of various types of cystic or necrotic brain tumor were significantly larger than the mean rCBV ratio (0.45+/-0.11) of the pyogenic cerebral abscess wall (P<0.001) by Student's t-test. It is concluded that the combined MR diffusion and perfusion imaging might be capable of differentiating an infected brain tumor from a pyogenic cerebral abscess.

Idiopathic pulmonary artery aneurysm: digital subtraction pulmonary angiography grossly underestimates the size of the aneurysm.

Pulmonary artery aneurysm is a rare disease entity. The majority of cases are associated with congenital cardiovascular diseases, infection, and trauma; idiopathic pulmonary artery aneurysm is extremely rare. Although conventional and digital subtraction pulmonary angiography remains as the imaging modality of choice for the pulmonary vessels, it is invasive and sometimes may be inaccurate. With the advent of spiral computed tomographic angiography (CTA), pulmonary artery aneurysm can be diagnosed noninvasively and accurately. We report a case of a 68-year-old man with idiopathic pulmonary artery aneurysm of the descending branch of right pulmonary artery where the true caliber of the aneurysm was significantly underestimated in the digital subtraction pulmonary angiography. The literatures of this rare condition are reviewed with the emphasis on the application of CTA in this disease.

Late temporal lobe necrosis in patients with nasopharyngeal carcinoma: evaluation with combined multi-section diffusion weighted and perfusion weighted MR imaging.

Late temporal lobe necrosis is a well-known and serious complication in patients with nasopharyngeal carcinoma (NPC) following radiotherapy. Owing to the close proximity to the skull base, the medial temporal lobes are inevitably included in the target volume of irradiation. Patients with NPC provide a unique opportunity in study of delay radiation effect in normal human brain. The objective of this study was to evaluate late temporal lobe radiation injury by combined multi-section diffusion weighted and perfusion weighted MR imaging. We prospectively studied 16 patients with typical clinical symptoms of late temporal lobe necrosis or other abnormalities in the temporal lobes incidentally detected by conventional MR imaging. All patients had a previous history of radiotherapy for histologically proven NPC. Conventional T1- and T2-weighted images, fast gradient echo with echo-planar diffusion-weighted and perfusion-weighted MR imaging were performed. Apparent diffusion coefficient (ADC) map and relative cerebral blood volume (rCBV) map were computed via commercially available software. MR diffusion and perfusion images were then analyzed and graded by two independent observers with focusing on the diffusion and perfusion mismatch. The temporal lobe lesions displayed marked high diffusion on the ADC map. The rCBV map also revealed marked hypoperfusion in these temporal lobe lesions in all patients. The areas of abnormality on the rCBV map were significantly larger than the lesions on the ADC map in 14 patients (observer 1) and 13 patients (observer 2). Since late temporal lobe necrosis is probably caused by damage of the endothelium of vessels and ischemia, perfusion and diffusion mismatch might imply injured tissue but potentially salvageable brain tissue. A mismatch may be potentially used to predict the response to treatment in-patients with late temporal lobe necrosis.

N-hydroxyformamide peptidomimetics as TACE/matrix metalloprotease inhibitors: oral activity via P1' isobutyl substitution.

N-Hydroxyformamide-class metalloprotease inhibitors were designed and synthesized, which have potent broad-spectrum activity versus matrix metalloproteases and TNF-alpha converting enzyme (TACE). Compound 13c possesses good oral and intravenous pharmacokinetics in the rat and dog.

X-Ray crystal structures of Candida albicans dihydrofolate reductase: high resolution ternary complexes in which the dihydronicotinamide moiety of NADPH is displaced by an inhibitor.

X-ray crystallographic analysis of 5-(4'-substituted phenyl)sulfanyl-2,4-diaminoquinazoline inhibitors in ternary complex with Candida albicans dihydrofolate reductase (DHFR) and NADPH revealed two distinct modes of binding. The two compounds with small 4'-substituents (H and CH3) were found to bind with the phenyl group oriented in the plane of the quinazoline ring system and positioned adjacent to the C-helix. In contrast, the more selective inhibitors with larger 4'-substituents (tert-butyl and N-morpholino) were bound to the enzyme with the phenyl group perpendicular to the quinazoline ring and positioned in the region of the active site that typically binds the dihydronicotinamide moiety of NADPH. The cofactor appeared bound to DHFR but with the disordered dihydronicotinamide swung away from the protein surface and into solution. This unusual inhibitor binding mode may play an important role in the high DHFR selectivity of these compounds and also may provide new ideas for inhibitor design.

Effect of ABO blood group mismatching on corneal epithelial cells: an in vitro study.

AIM: To determine, in vitro, the effects of blood group ABO mismatching on corneal epithelial cells. METHODS: Corneal epithelial cell cultures were established from 32 human cadaver donor eyes. Epithelial cells (100 microl of 4 x 10(2) cells per microl) were incubated for 4 hours with antibodies against blood group antigens A, B, and AB, with and without complement. Cell lysis was assayed by a chemiluminescent assay using Cytolite reagent. Live cells, remaining after incubation, were counted in a scintillation counter. The blood group of the donors was determined retrospectively, in a blinded manner. RESULTS: Retrospective tracing of donor blood groups was possible for 20 donors. In all cases the blood group corresponded with that suggested by the cell lysis assay. Significant cell lysis was observed when known A group cells were incubated with anti-A and anti-AB antibody, B group cells were incubated with anti-B and AB antibody, and AB group cells were incubated with anti-AB antibody. Lysis occurred only in the presence of complement. No lysis of O group cells was observed with any of the antibodies. In all cases, lysis was observed only with neat (serum) antibody concentrations. CONCLUSIONS: Blood group ABO mismatching results in significant lysis of corneal epithelial cells. The antibody concentration required for lysis equals that found in serum. Such levels of antibody are unlikely to be achieved in tears and/or aqueous. This may offer an explanation for the conflicting reports of the studies on the effect of blood group matching on corneal grafts. The variability in the outcome may reflect the levels of antibodies gaining access to the corneal cells and not the mismatching alone.

MR diffusion-weighted imaging of kidney: differentiation between hydronephrosis and pyonephrosis.

The objective of the study was to evaluate the capability and reliability of the magnetic resonance (MR) diffusion-weighted imaging (DWI) in differentiation between hydronephrosis and pyonephrosis. Single-shot echoplanar MR diffusion-weighted imaging was performed in 12 patients who had dilatation of the renal pelvis and calyces detected by ultrasonography (US). Microbiological tests confirmed that there were four cases of pyonephrosis and eight cases of hydronephrosis. Signal intensities of the collecting (pelvicalyceal) systems on the diffusion-weighted images and apparent diffusion coefficient (ADC) maps were noted. ADC values of the pelvicalyceal system in all patients were computed and compared using Student's t test. On diffusion-weighted images, the pelvicalyceal system of the hydronephrotic kidney was hypointense while the pelvicalyceal system of the pyonephrotic kidney was markedly hyperintense. The mean ADCs of the hydronephrotic and pyonephrotic renal pelvis were 2.98 +/- 0.65 x 10(-3) and 0.64 +/- 0.35 x 10(-3) mm(2)/s, respectively. The extremely low ADC of the renal pelvis of the pyonephrotic kidney accounted for its signal hyperintensity on diffusion-weighted images as well as signal hypointensity on ADC maps. In conclusion, the MR diffusion-weighted imaging may be a reliable tool to differentiate pyonephrosis from hydronephrosis.