Perspectives and expectations of stroke survivors using egocentric cameras for monitoring hand function at home: a mixed methods study

PURPOSE

Most stroke survivors have remaining upper limb impairment six months after stroke and require additional rehabilitation and help from family members to enhance their performance of daily activities. First-person (egocentric) video has been proposed to capture the activities of daily living (ADLs) of stroke survivors in order to assess their hand function at home. This study explored the experiences and expectations of stroke survivors regarding the use of egocentric cameras in daily life for rehabilitation applications.

METHODS

Twenty-one chronic stroke survivors recruited for the study were asked to record three sessions of 1.5 h of video of their ADLs at home over two weeks. Their experiences and expectations after completing the recordings were discussed using a structured questionnaire and a semi-structured interview. The questionnaire and interview data were analysed using descriptive statistics and content analysis, respectively. The results were further integrated using a mixed methods analysis for mutual explanation and elaboration.

RESULTS

The themes generated were Camera Usability, Privacy Concerns Related to Home Recordings, Future Use of the Camera in Public, and Information Usefulness. The participants perceived that the camera was easy to use, the information obtained from the recordings was beneficial, and no major concerns about recording at home. A discreet camera and a solution to privacy issues were prerequisites to recording tasks in public.

CONCLUSIONS

There was high acceptance among stroke survivors regarding the use of wearable cameras for rehabilitation purposes in the future. Concerns to be managed include discomfort, self-consciousness, and the privacy of others.Implications for rehabilitationThe egocentric camera was easy for the stroke survivors to use at home. However, they expressed a preference for cameras to be less noticeable and lighter in the future to minimize self-consciousness and discomfort.Expectations for future use of an egocentric camera for upper limb rehabilitation at home from the perspectives of stroke survivors included receiving feedback on their hand function in daily life and guidance on how to improve function.Privacy concerns of stroke survivors regarding recording activities of daily living were mostly avoidable by planning in advance. However, some personal hygiene tasks and virtual meetings were recorded by accident. A checklist of common activities that may raise privacy issues can be provided along with the camera to serve as a reminder to avoid these issues.

Recognizing hand use and hand role at home after stroke from egocentric video

Hand function is a central determinant of independence after stroke. Measuring hand use in the home environment is necessary to evaluate the impact of new interventions, and calls for novel wearable technologies. Egocentric video can capture hand-object interactions in context, as well as show how more-affected hands are used during bilateral tasks (for stabilization or manipulation). Automated methods are required to extract this information. The objective of this study was to use artificial intelligence-based computer vision to classify hand use and hand role from egocentric videos recorded at home after stroke. Twenty-one stroke survivors participated in the study. A random forest classifier, a SlowFast neural network, and the Hand Object Detector neural network were applied to identify hand use and hand role at home. Leave-One-Subject-Out-Cross-Validation (LOSOCV) was used to evaluate the performance of the three models. Between-group differences of the models were calculated based on the Mathews correlation coefficient (MCC). For hand use detection, the Hand Object Detector had significantly higher performance than the other models. The macro average MCCs using this model in the LOSOCV were 0.50 ± 0.23 for the more-affected hands and 0.58 ± 0.18 for the less-affected hands. Hand role classification had macro average MCCs in the LOSOCV that were close to zero for all models. Using egocentric video to capture the hand use of stroke survivors at home is technically feasible. Pose estimation to track finger movements may be beneficial to classifying hand roles in the future.

Validity of Novel Outcome Measures for Hand Function Performance After Stroke Using Egocentric Video

BACKGROUND

Evaluating upper limb (UL) interventions after stroke calls for outcome measures that describe impact on daily life in the community. UL use ratio has been used to quantify the performance domain of UL function, but generally focuses on arm use only. A hand use ratio could provide additional information about UL function after stroke. Additionally, a ratio based on the role of the more-affected hand in bilateral activities (stabilizer or manipulator) may also reflect hand function recovery. Egocentric video is a novel modality that can record both dynamic and static hand use and hand roles at home after stroke.

OBJECTIVE

To validate hand use and hand role ratios from egocentric video against standardized clinical UL assessments.

METHODS

Twenty-four stroke survivors recorded daily tasks in a home simulation laboratory and their daily routines at home using egocentric cameras. Spearman's correlation was used to compare the ratios with the Fugl-Meyer Assessment-Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), and Motor Activity Log-30 (MAL, Amount of Use (AoU), and Quality of Movement (QoM)).

RESULTS

Hand use ratio significantly correlated with the FMA-UE (0.60, 95% CI: 0.26, 0.81), ARAT (0.44, CI: 0.04, 0.72), MAL-AoU (0.80, CI: 0.59, 0.91), and MAL-QoM (0.79, CI: 0.57, 0.91). Hand role ratio had no significant correlations with the assessments.

CONCLUSION

Hand use ratio automatically extracted from egocentric video, but not hand role ratio, was found to be a valid measure of hand function performance in our sample. Further investigation is necessary to interpret hand role information.

Identifying Hand Use and Hand Roles After Stroke Using Egocentric Video

Objective: Upper limb (UL) impairment impacts quality of life, but is common after stroke. UL function evaluated in the clinic may not reflect use in activities of daily living (ADLs) after stroke, and current approaches for assessment at home rely on self-report and lack details about hand function. Wrist-worn accelerometers have been applied to capture UL use, but also fail to reveal details of hand function. In response, a wearable system is proposed consisting of egocentric cameras combined with computer vision approaches, in order to identify hand use (hand-object interactions) and the role of the more-affected hand (as stabilizer or manipulator) in unconstrained environments. Methods: Nine stroke survivors recorded their performance of ADLs in a home simulation laboratory using an egocentric camera. Motion, hand shape, colour, and hand size change features were generated and fed into random forest classifiers to detect hand use and classify hand roles. Leave-one-subject-out cross-validation (LOSOCV) and leave-one-task-out cross-validation (LOTOCV) were used to evaluate the robustness of the algorithms. Results: LOSOCV and LOTOCV F1-scores for more-affected hand use were 0.64 ± 0.24 and 0.76 ± 0.23, respectively. For less-affected hands, LOSOCV and LOTOCV F1-scores were 0.72 ± 0.20 and 0.82 ± 0.22. F1-scores for hand role classification were 0.70 ± 0.19 and 0.68 ± 0.23 in the more-affected hand for LOSOCV and LOTOCV, respectively, and 0.59 ± 0.23 and 0.65 ± 0.28 in the less-affected hand. Conclusion: The results demonstrate the feasibility of predicting hand use and the hand roles of stroke survivors from egocentric videos.

Capturing Representative Hand Use at Home Using Egocentric Video in Individuals with Upper Limb Impairment

Impaired hand function after neurological injuries can have a major impact on independence and quality of life. Most existing upper limb assessments are carried out in person, which is not always indicative of hand use in the community. Novel approaches to capture hand function in daily life are required to measure the true impact of rehabilitation interventions. Egocentric video combined with computer vision for automated analysis has been proposed to evaluate hand use at home. However, there are limitations to the duration of continuous recordings. We present a protocol designed to ensure that the videos obtained are representative of daily routines while respecting participant privacy. A representative recording schedule is selected through a collaborative process between the researchers and participants, to ensure that the videos capture natural tasks and performance, while being useful for hand assessment. Use of the equipment and procedures is demonstrated to the participants. A total of 3 h of video recordings are scheduled over two weeks. To reduce privacy concerns, participants have full control to start and stop recordings, and the opportunity to edit the videos before returning them to the research team. Reminders are provided, as well as help calls and home visits if necessary. The protocol was tested with 9 stroke survivors and 14 individuals with cervical spinal cord injury. The videos obtained contained a variety of activities, such as meal preparation, dishwashing, and knitting. An average of 3.11 ± 0.98 h of video were obtained. The recording periods varied from 12-69 d, due to illness or unexpected events in some cases. Data was successfully obtained from twenty-two out of 23 participants, with 6 participants requiring assistance from the investigators during the home recording period. The protocol was effective for collecting videos that contained valuable information about hand function at home after neurological injuries.

Generalizability of Hand-Object Interaction Detection in Egocentric Video across Populations with Hand Impairment

Stroke survivors often experience unilateral sensorimotor impairment. The restoration of upper limb function is an important determinant of quality of life after stroke. Wearable technologies that can measure hand function at home are needed to assess the impact of new interventions. Egocentric cameras combined with computer vision algorithms have been proposed as a means to capture hand use in unconstrained environments, and have shown promising results in this application for individuals with cervical spinal cord injury (cSCI). The objective of this study was to examine the generalizability of this approach to individuals who have experienced a stroke. An egocentric camera was used to capture the hand use (hand-object interactions) of 6 stroke survivors performing daily tasks in a home simulation laboratory. The interaction detection classifier previously trained on 9 individuals with cSCI was applied to detect hand use in the stroke survivors. The processing pipeline consisted of hand detection, hand segmentation, feature extraction, and interaction detection. The resulting average F1 scores for affected and unaffected hands were 0.66 ± 0.25 and 0.80 ± 0.15, respectively, indicating that the approach is feasible and has the potential to generalize to stroke survivors. Using stroke-specific training data may further increase the accuracy obtained for the affected hand.

Point spread function of a collinear holographic storage system

A paraxial solution to the coaxial holographic storage algorithm is proposed based on the scalar diffraction theory and a VOHIL model (volume hologram being an integrator of the lights emitted from elementary light sources), which can give insight into the optical characteristics of the collinear holographic storage system in an effective way, including the point spread function and shift selectivity. The paraxial solution shows that the reference pattern is the key issue in the point spread function. Thus, the bit error rate of the system can be improved by changing the reference pattern. The proposed solution will be useful in the design of a new reference pattern to perform a high-quality readout pattern in the coaxial holographic storage system.

Unraveling the formation of HCPH(X2A') molecules in extraterrestrial environments: crossed molecular beam study of the reaction of carbon atoms, C(3Pj), with phosphine, PH3(X1A1)

The reaction between ground state carbon atoms, C(3P(j)), and phosphine, PH3(X(1)A1), was investigated at two collision energies of 21.1 and 42.5 kJ mol(-1) using the crossed molecular beam technique. The chemical dynamics extracted from the time-of-flight spectra and laboratory angular distributions combined with ab initio calculations propose that the reaction proceeds on the triplet surface via an addition of atomic carbon to the phosphorus atom. This leads to a triplet CPH3 complex. A successive hydrogen shift forms an HCPH2 intermediate. The latter was found to decompose through atomic hydrogen emission leading to the cis/trans-HCPH(X(2)A') reaction products. The identification of cis/trans-HCPH(X(2)A') molecules under single collision conditions presents a potential pathway to form the very first carbon-phosphorus bond in extraterrestrial environments like molecular clouds and circumstellar envelopes, and even in the postplume chemistry of the collision of comet Shoemaker-Levy 9 with Jupiter.

Cloning, characterization, and phylogenetic analysis of a shrimp white spot syndrome virus gene that encodes a protein kinase

An open reading frame (ORF) that encodes a 715-amino-acid polypeptide was found in an 8421-bp EcoRI fragment of the shrimp white spot syndrome virus (WSSV) genome. The polypeptide shows significant homology to eukaryotic serine/threonine protein kinase (PK) and contains the major conserved subdomains for eukaryotic protein kinases. Coupled in vitro transcription and translation generated a protein having an apparent molecular mass of about 87 kDa according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. For transcriptional analysis of the pk gene, total RNA was isolated from WSSV-infected shrimp at different times after infection. Northern blot analysis with pk-specific riboprobe found a major and a minor transcript of 2.7 and 5.7 kb, respectively. Rapid amplification of the 5' cDNA ends of the major 2.7-kb pk transcript showed that there were two transcriptional initiation sites located at nucleotide residues -38(G) and -39(G) relative to the ATG translational start codon. Temporal expression analysis by RT-PCR indicated that the transcription of the pk gene started 2 h after infection and continued for at least 60 h. Phylogenetic analysis showed that WSSV protein kinase does not have any close relatives and does not fall into any of the major protein kinase groups.

New DR5 sequences: a novel DRB1*11122 allele identified in Paiwan tribe members of Taiwan and a corrected sequence for the DRB1*1201 allele

We report herein the identification of a new DRB1 allele using sequence-based typing (SBT). This novel allele, HLA-DRB1*11122, was found in an aboriginal individual (SWP71) from the Paiwan tribe in the southern part of Taiwan. This individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4001/4002, HLA-DRB1*11122/15011, HLA-DRB3*0202, and HLA-DRB5*01011. This new allele differs from DRB1*1112 in the polymorphic exon 2 only at codon 34 (CAA-->CAG; both specify glutamine) and from DRB1*1110 in the exon 2 sequence only at codon 32 (CAT-->TAT; H32T). The most likely candidate allele which is found in the aboriginal populations of Taiwan and which may mutate into this new allele is DRB1*11011. DRB1*11122 allele differs from DRB1*11011 allele in the polymorphic exon 2 at both codon 34 (CAA-->CAG) and codon 37 (TAC-->TTC; T37F). This novel HLA-DRB1*11122 allele was also found in another aboriginal individual (SWP90) from the same Paiwan tribe. This SWP90 individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4002/5502, HLA-DRB1*11122/1201, and HLA-DRB3*01011/0202. However, the original DRB1*1201 sequence from HERLUFF was found to be erroneously reported and the corrected sequence from SWP90 is now presented herein.

The in vitro inhibitory effect of flavonoid astilbin on 3-hydroxy-3-methylglutaryl coenzyme A reductase on Vero cells

BACKGROUND

Epidemiological studies have shown that hypercholesterolemia is a major risk factor for coronary heart disease. In clinical trials of lipid lowering therapy, 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase inhibitor has been shown to decrease cardiac events and mortality. Flavonoids are polyphenolic natural antioxidants existing in vegetables, fruits and beverages such as tea and wine. Previous studies have shown that some antioxidants had hypocholesterolemic effect, and flavonoid intake was associated with the decrease of mortality from coronary artery disease. The aim of this study was to evaluate the inhibitory effect of flavonoids on HMG-CoA reductase.

METHODS

The methods for analysis of specific inhibitors of mevalonate biosynthesis have been well-established, using Vero cells, a cell line obtained from kidneys of African green monkeys. Flavonoids isolated from different traditional Chinese herbs were dissolved in DMSO and incubated with Vero cells with or without the addition of 1 mM mevalonate or 5 mM sodium acetate in order to observe cell growth for 24 h.

RESULTS

Concentrations of 1 mM mevalonate or 5 mM sodium acetate were added into culture medium in order to observe the effect on cell growth. Different concentrations of pravastatin to inhibit cell growth were used as a positive control. About 40 flavonoid compounds were used for study, only one compound, astilbin (belonging to the flavonol group), showed significant inhibition of Vero cell growth.

CONCLUSIONS

This study shows that one flavonoid compound, isolated from traditional medicinal herbs, may be an effective HMG-CoA reductase inhibitor which might be developed into a new hypocholesterolemic agent.

99mTc-sulphur-colloid and heat-denatured 99mTc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy

A 17 x 12 x 5-cm giant intrapelvic mass in a 14-year-old girl is reported. This mass developed 6 years after a splenectomy for splenic torsion. The heat-denatured 99mTc-labelled red cell scan and 99mTc-sulphur-colloid scan confirmed the specific red cell sequestration function and reticuloendothelial activity in the giant intrapelvic spleen. The size and development of the giant intrapelvic spleen are unusual. The usefulness of functional images to diagnosis the nature of the intrapelvic mass is well demonstrated.

Polymorphism of human HLA-DRB1 antigens generated by genetic exchange between DR2 (DRB1*15011) and DR6 (DRB1*1405) alleles: a novel DRB1 allele (DRB1*1437) identified in a Paiwan tribe member of Taiwan

We report herein the identification of a new DRB1 allele using sequence-based typing (SBT). This novel allele, HLA-DRB1*1437, was found in an aboriginal individual from the Paiwan tribe in the southern part of Taiwan. This individual was typed by SBT method as having an HLA genotype of HLA-A*02011/0203, HLA-B*15011/3901, HLA-DRB1*11011/1437, HLA-DRB3*0202/0202, and HLA-DPB1*0501/1301. This new allele differs from DRB1*1309 in the 5'-end nucleotide sequence of polymorphic exon 2 at codon 16 (CAT-->CAA; H16Q), codon 37 (AAC-->TTC; R37F), codon 47 (TTC-->TAC; F47Y), and codon 58 (GCC-->GCT; both specify alanine). By sequence comparison, it was found that this new allele has a 5'-end sequence (from amino acid residues 7 to 66) identical to that found in the DRB1*1405 allele and a 3'-end sequence (from amino acid residues 58 to 94) identical to that found in the DRB1*15011 allele. Both DRB1*1405 and DRB1*15011 alleles have been identified among the Paiwan members (Note).

Breast uptake of iodine-131 mimicking lung metastases in a thyroid cancer patient with a pituitary tumour

We report a case of a 44-year-old female thyroid cancer patient with a pituitary tumour. 131I whole body scanning showed a change of chest uptake from a unilateral crescent uptake to a bilateral full breast uptake pattern. Hyperprolactinaemia and a pituitary tumour were diagnosed as a result of observing the 131I breast uptake.

Diagnosis and treatment of pyogenic psoas abscess in diabetic patients: usefulness of computed tomography and gallium-67 scanning

OBJECTIVES

To examine retrospectively the clinical presentations, microbiologic characteristics, and treatment outcomes of psoas abscess in patients with diabetes mellitus (DM) and to assess the usefulness of computed tomography and gallium-67 scanning in its early diagnosis.

METHODS

During a 9-year period, psoas abscesses in patients with DM were collected at a medical center. The clinical history and associated etiologic factors, microbiologic results, clinical outcomes, and hospitalization days were recorded. The use of imaging in the diagnosis of psoas abscess and other concomitant infectious lesions was also studied.

RESULTS

Fifteen patients with DM and psoas abscess (13 women and 2 men; mean age 58.7 +/- 9.0 years) were found. The most frequent symptom was fever (12 of 15). Of the six different microorganisms that grew in the blood and/or abscess cultures, Staphylococcus aureus was the most frequent (7 of 15). The most commonly associated pathologic finding was vertebral osteomyelitis (5 of 15). Computed tomography and/or magnetic resonance imaging confirmed the diagnosis of psoas abscesses in all 15 patients. The gallium-67 scan especially aided in the diagnosis of the patients who had initially been diagnosed as having fever of unknown origin (4 of 5) and in the diagnosis of concomitant lesions (9 of 12). Debridement or surgical drainage of the abscess was done in 12 patients. All the patients received adequate antibiotic treatment. However, the mortality rate was 20%. The average hospitalization stay was 42.7 +/- 20.7 days.

CONCLUSIONS

Psoas abscess in patients with DM is a disease with both diagnostic and therapeutic challenges. We found the infecting microorganisms to be variable and the mortality rate high.

Identification and characterization of a shrimp white spot syndrome virus (WSSV) gene that encodes a novel chimeric polypeptide of cellular-type thymidine kinase and thymidylate kinase

From previously constructed genomic libraries of a Taiwan WSSV isolate, a putative WSSV tk-tmk gene was identified. Uniquely, the open reading frame (ORF) of this gene was predicted to encode a novel chimeric protein of 388 amino acids with significant homology to two proteins: thymidine kinase (TK) and thymidylate kinase (TMK). Northern blot analysis with a WSSV tk-tmk-specific riboprobe detected a major transcript of 1.6 kb. When healthy adult Penaeus monodon shrimp were inoculated with WSSV, the tk-tmk gene transcript was first detected by RT-PCR analysis at 4 h postinfection and transcription levels continued to increase over the first 18 h. The gene's major in vitro transcription and translation product, equivalent to the predicted size (43 kDa), is a single chimeric protein that includes both the TK and TMK functional motifs. Evidence for phylogenetic analysis and sequence alignment suggested that the gene may have resulted from the fusion of a cellular-type TK gene and a cellular-type TMK gene. Its unique arrangement may also provide a valuable gene marker for WSSV.

Transcriptional analysis of the ribonucleotide reductase genes of shrimp white spot syndrome virus

The causative agent of white spot syndrome (WSS) is a large double-stranded DNA virus, WSSV, which is probably a representative of a new genus, provisionally called Whispovirus. From previously constructed WSSV genomic libraries of a Taiwan WSSV isolate, clones with open reading frames (ORFs) that encode proteins with significant homology to the class I ribonucleotide reductase large (RR1) and small (RR2) subunits were identified. WSSV rr1 and rr2 potentially encode 848 and 413 amino acids, respectively. RNA was isolated from WSSV-infected shrimp at different times after infection and Northern blot analysis with rr1- and rr2-specific riboprobes found major transcripts of 2.8 and 1.4 kb, respectively. 5' RACE showed that the major rr1 transcript started at a position of -84 (C) relative to the ATG translational start, while transcription of the rr2 gene started at nucleotide residue -68 (T). A consensus motif containing the transcriptional start sites for rr1 and rr2 was observed (TCAc/tTC). Northern blotting and RT-PCR showed that the transcription of rr1 and rr2 started 4-6 h after infection and continued for at least 60 h. The rr1 and rr2 genes thus appear to be WSSV "early genes."

Using surfactants to enhance the analyte signals in activated carbon, surface-assisted laser desorption/ionization (SALDI) mass spectrometry

The effect of surface activity in surface-assisted laser desorption/ionization (SALDI) mass spectrometry was examined. Several surfactants, including p-tolunensulfonic acid (PTSA), sodium dodecyl sulfate and alkyltrimethylammonium bromide, were used as analytes or additives in the SALDI matrix to demonstrate the surface activity effect. The experimental results demonstrate that analytes that have good surface activity have good sensitivity. Adding suitable amounts of surfactants to the SALDI matrix can dramatically enhance the sensitivity of analytes lacking surface activity. We propose that the enhancement of analyte signals is due to the ionic interaction between ionic surfactants and analytes because non-ionic surfactant additives in the SALDI matrix do not affect the analyte signals. The detection limit of methylephedrine can be as low as 100 pg in the SALDI analysis of 0.5 M PTSA additive in the SALDI matrix. Although other surfactants can also be used as matrix additives to enhance the analyte signal, they do not improve the ion abundance as much as PTSA does.

Gallium-67 scanning in endogenous Klebsiella endophthalmitis with unknown primary focus

A whole-body gallium-67 (Ga-67) scan of a 61-y-old male with diabetes mellitus who suffered from endogenous Klebsiella endophthalmitis is reported. The scan revealed right orbital and lower abdominal lesions. Urinary analysis revealed pyuria. The causes of endogenous Klebsiella endophthalmitis and the usefulness of Ga-67 are discussed.

Pyometra as a lower abdominal doughnut sign on a Ga-67 scan

A 77-year-old woman was referred for Ga-67 scan to evaluate intermittent fever and chills that had lasted more than 20 days. The Ga-67 whole-body scan revealed a doughnut-shaped Ga-67 accumulation in the lower abdominal region. Combined Ga-67 and Tc-99m MDP bone scan confirmed that this activity was in the uterus, because the shape of the urinary bladder on bone scan was different from that of the Ga-67-avid lesion. Pyometra was proved during operation, and pus culture was performed.

Cerebral perfusion SPECT in transient ischemic attack

PURPOSE

The purpose of our study is to evaluate the efficacy of cerebral perfusion single photon emission computerized tomography (SPECT) in patients with transient ischemic attack (TIA).

METHODS

Thirty-seven patients with TIA were collected for study. All patients had transient focal neurological symptoms or signs with complete recovery within 24 h after onset. The patients underwent cerebral perfusion SPECT between 6 h and 11 days after onset, with 10 cases performed within 24 h (group A), nine cases performed between 1 and 3 days (group B), 11 cases performed between 3 and 5 days (group C), and seven cases performed after more than 5 days (group D). A semi-quantitative method was used for analyzing the SPECT data, and the difference ratios between lesion side and contralateral normal side were calculated on each pair of regions of interest.

RESULTS

In total, 78.4% (29/37) of patients had reduced perfusion in the cerebral cortical regions or deep nuclei, and the regions with reduced perfusion corresponded with clinical presentations of the patients. The abnormal rate with reduced perfusion was 90.0% in group A, 77.8% in group B, 72.7% in group C and 71.4% in group D. Cross cerebellar diaschisis (CCD) was present in seven patients, and all of the primary cerebral perfusion defects of these patients were located at the territory of left or right middle cerebral artery.

CONCLUSION

Cerebral perfusion SPECT is a potential tool to detect cerebral perfusion defects and CCD in patients with TIA. Although the perfusion defect may persist more than 5 days after onset, we suggest cerebral perfusion SPECT should be performed as soon as possible.

Analysis of a genomic segment of white spot syndrome virus of shrimp containing ribonucleotide reductase genes and repeat regions

White spot syndrome is a worldwide disease of penaeid shrimp. The disease agent is a bacilliform, enveloped virus, white spot syndrome virus (WSSV), with a double-stranded DNA genome that probably contains well over 200 kb. Analysis of a 12.3 kb segment of WSSV DNA revealed eight open reading frames (ORFs), including the genes for the large (RR1) and small (RR2) subunits of ribonucleotide reductase. The rr1 and rr2 genes were separated by 5760 bp, containing several putative ORFs and two domains with multiple sequence repeats. The first domain contained six direct repeats of 54 bp and is part of a coding region. The second domain had one partial and two complete direct repeats of 253 bp at an intergenic location. This repeat, located immediately upstream of rr1, has homologues at several other locations on the WSSV genome. Phylogenetic analysis of RR1 and RR2 indicated that WSSV belongs to the eukaryotic branch of an unrooted parsimonious tree and, further, seems to suggest that WSSV and baculoviruses probably do not share an immediate common ancestor. The present analysis of WSSV favours the view that this virus is either a member of a new genus (Whispovirus) within the Baculoviridae or a member of an entirely new virus family.

Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry

Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution.

The specific gallium-67 scan uptake pattern in psoas abscesses

A psoas abscess is a rare clinical entity that presents diagnostic and therapeutic challenges. In this retrospective study, we reviewed gallium-67 scan findings in cases of psoas abscess to determine the specific uptake pattern and the usefulness of 67Ga scans in diagnosis and management. Fifteen psoas abscess lesions in 13 patients who had undergone a 67Ga scan during an 8-year period were found in the hospital computer. All but two of the patients had been diagnosed as having fever of unknown origin, urinary tract infection or another irrelevant disease prior to the 67Ga scan. Of the 15 psoas abscess lesions, 12 (80%) could be clearly diagnosed on the basis of the specific 67Ga uptake pattern, in which: (1) the oblique direction of the 67Ga-avid lesion correlates with the orientation of the psoas muscle from the lumbar region to the hip joint region; (2) the lesion does not cross the abdominal midline; (3) the lesion goes through the inguinal region; and (4) the lesion involves at least two-thirds of the whole length of the psoas muscle. The specific features may help in the differentiation of psoas abscess from other intra-abdominal lesions or normal bowel distribution, especially with single-photon emission tomographic images. In 7 of 13 patients (53.8%) the 67Ga scan findings contributed to the clinical management of the patients by first detecting the focus of the infection. Multiple concomitant 67Ga-avid lesions were found in ten patients. In conclusion, the specific features as well as the whole-body survey with 67Ga scan are useful and important in the diagnosis of psoas abscesses and the detection of unexpected concomitant multiple infectious foci in clinically suspicious infectious disease patients.

Rectus abdominis rhabdomyolysis after sit ups: unexpected detection by bone scan

Uptake of technetium-99m methylene diphosphonate by the rectus abdominis muscle was unexpectedly found in a 29 year old man who had started to perform 30 to 40 sit ups a day for five days before the bone scan. After a week of rest, serum creatine kinase activity was still abnormal but muscle uptake of technetium-99m methylene diphosphonate had ceased. This specific muscle injury after short term sit ups as well as the resolution of the phenomenon within a week are of interest.

Quantitative cerebral perfusion SPECT in systemic lupus erythematosus with severe central nervous involvement--before and after methylprednisolone pulse therapy

Severe cerebral involvement may occur in patients with systemic lupus erythematosus. Methylprednisolone pulse therapy is a management choice for those with severe cerebral involvement. However, its effectiveness is uncertain. This article describes Tc-99m HMPAO cerebral perfusion single-photon emission computerized tomography to document the restoration of cerebral perfusion after methylprednisolone pulse therapy in a case of systemic lupus erythromatosus with severe cerebral manifestations.

False-positive whole-body iodine-131 scan due to intrahepatic duct dilatation

Focal retention of radioactivity in the liver on whole-body 131I scan was interpreted as a metastatic lesion in a patient with well-differentiated thyroid cancer. Intrahepatic duct dilatation, usually resulting from biliary tract obstruction by bile stone, is a common disorder and may cause bile stasis. A patient with papillary thyroid cancer and a previous history of biliary tract stones had focal retention of radioactivity in the liver on whole-body 131I scan. Abdominal CT, endoscopic retrograde cholagiopancreatography, radionuclide cholangiography and sequential 131I scans demonstrated that this focal retention of radioactivity was caused by intrahepatic duct dilatation. Focal retention of radioactivity is visualized on delayed images but not on early images. The radioactivity initially increases and then decreases on following days.

Diuretic renography findings in enterovesical fistula

A 73-year-old male presented with a 2 week history of gross haematuria and faecal material in the urine. Bone scan for cancer work-up showed 99T(cm)-MDP radioactivity accumulation in the transverse and descending colon. A 99T(cm)-DTPA diuretic renogram was arranged to study renal function and to determine the location of the enterovesical fistula. Diuretic renography demonstrated extraurinary tract radioactivity in the sigmoid colon in the early images, extending to the descending and transverse colon in the subsequent dynamic images. A sigmoid colon adenocarcinoma with bladder wall invasion and fistula formation was confirmed at surgical operation. The impressive dynamic diuretic renography study in this patient was helpful in determining the location of the fistula and in planning surgical management.

Incorporation of allograft for acetabular reconstruction. Single photon emission CT in 21 hip arthroplasties followed for 2.5-5 years

We studied 21 hips in 20 patients who had acetabular reconstruction with a femoral head allograft in primary (n 2) and secondary (n 19) total hip arthroplasty. The fate of the graft was evaluated by serial bone SPECTs (single photon emission computed tomography). With a mean follow-up period of 37 (30-60) months, 14 of the 21 hips showed evidence of incorporation at earliest 13 (6-18) months after operation. There was no correlation between the fate of allograft and the compatibility of A, B, O blood typing between host and donor, the use of bone cement in the fixation of acetabular component, or loosening of the acetabular component.

Receptors for peptide YY and neuropeptide Y on guinea pig pancreatic acini

We examined the effects of peptide YY (PYY), neuropeptide Y (NPY), and their analogues on dispersed pancreatic acini. Binding of [125I]PYY to acini was saturable, reversible, and specific, and PYY binding was best fit with a two-site model. The relative potencies for inhibiting [125I]PYY binding were PYY > or = NPY > NPY(13-36). There was no inhibition of binding with [Leu31,Pro34]NPY, PYX-2, or pancreatic polypeptide. Both PYY and NPY (0.1 microM) inhibited amylase release stimulated by vasoactive intestinal polypeptide (VIP) (0.3 nM) and forskolin (1 microM) by about 30%, but not that stimulated by cholecystokinin-8 or bombesin. The relative potencies for inhibiting VIP-stimulated amylase release were PYY > or = NPY > NPY(13-36), the same as those for inhibiting VIP-stimulated cAMP increase in acini. No inhibition was detected with [Leu31,Pro34]NPY. This work demonstrates Y2 receptors on guinea pig pancreatic acini mediating inhibitory actions of PYY and NPY on pancreatic enzyme secretion.

[The use of rifampin in the treatment of infection due to Staphylococcus aureus]

Infection due to Staphylococcus aureus continues to be a source of significant morbidity and mortality. However, its treatment is increasingly complicated by the rising prevalence of resistance to antibiotics. Apart from the two recognized modes of staphylococcal resistance, namely, penicillinase production and intrinsic resistance, Sabath and associates have described a third type in which resistance is manifested by susceptibility to growth inhibition but tolerance to the lethal action of bactericidal agents. The mechanism of tolerance is attributed to a deficiency of autolytic enzyme activity in the part of bacteria, possibly secondary to an inhibition of autolysins in the tolerant staphylococcal strains. These strains are found in patients with infections responding poorly to treatment with cell-wall active antibiotics including vancomycin. Because of its unique mechanism of action and pharmacokinetic properties, rifampin has been reported to be the most active among 65 antistaphylococcal agents tested and have the capacity to kill intraleukocytic staphylococci. We present 2 cases who were cured following the addition of rifampin to previously established regimens. Case 1 was a 40-year-old male who had fever, cough, dyspnea, a right elbow abscess and left leg swelling for 2 weeks prior to admission. Culture of purulent material from the elbow abscess grew staphylococcus aureus. Chest X-ray showed bilateral septic embolism and phleborheography showed partial deep vein occlusion of the left ileofemoral vein. Case 2 was 22-year-old female with fever, chills and cough for 3 weeks. Blood culture grew staphylococcus aureus, and Chest X-ray revealed bilateral septic embolism with pneumonia. Neither of them responded to standard antibiotics which were judged adequate by in vitro sensitivity tests. Clinical cure was later obtained after rifampin was added to the regimens. These results suggest that rifampin may be a useful adjunct in the therapy of staphylococcal infections.

Barrett's esophagus in patients with symptomatic reflux esophagitis

We evaluated the frequency with which Barrett's esophagus (BE) occurs in patients with symptomatic reflux esophagitis, and compared the clinical endoscopic and manometric features of patients with Barrett's esophagus with those of patients who had non-Barrett's esophagitis (NBE). The effect of 6 months' medical treatment on BE patients was reevaluated by repeating manometry, endoscopy, and biopsy. Esophageal manometry was performed by perfusion technique and endoscopic biopsies were obtained. There were 180 patients; 20 (11%) were found to have BE. The vast majority of BE patients were caucasians. BE patients had symptoms of gastroesophageal reflux for a longer time than did NBE patients. Mean lower esophageal sphincter pressure in BE patients was lower than that in NBE patients. On medical treatment, the severity of esophagitis as judged by endoscopic criteria in BE patients was reduced, but there was no increase in lower esophageal sphincter pressure and no regression of the columnar epithelium.

Sclerosing cholangitis and oxalate urolithiasis in ulcerative colitis

We report a 56-year-old man with sclerosing cholangitis and oxalate urolithiasis. These complications occurred five years after proctocolectomy and ileostomy were performed for ulcerative colitis. Two years before, at the time of proctocolectomy, there was no clinical or biochemical evidence of liver abnormality. The occurrence and progression of sclerosing cholangitis five years after proctocolectomy is unusual. Also unusual is the occurrence of oxalate urolithiasis; more common in ulcerative colitis, especially after ileostomy, are uric acid stones.