Mating and social exposure induces an opioid-dependent conditioned place preference in male but not in female prairie voles (Microtus ochrogaster).

In rodents, sexual stimulation induces a positive affective state that is evaluated by the conditioned place preference (CPP) test. Opioids are released during sexual behavior and modulate the rewarding properties of this behavior. Prairie voles (Microtus ochrogaster) are a socially monogamous species, in which copulation with cohabitation for 6h induces a pair bond. However, the mating-induced reward state that could contribute to the establishment of the long-term pair bond has not been evaluated in this species. The present study aimed to determine whether one ejaculation or cohabitation with mating for 6h is rewarding for voles. We also evaluated whether this state is opioid dependent. Our results demonstrate that mating with one ejaculation and social cohabitation with mating for 6h induce a CPP in males, while exposure to a sexually receptive female without mating did not induce CPP. In the female vole, mating until one ejaculation, social cohabitation with mating, or exposure to a male without physical interaction for 6h did not induce CPP. To evaluate whether the rewarding state in males is opioid dependent, the antagonist naloxone was injected i.p. The administration of naloxone blocked the rewarding state induced by one ejaculation and by social cohabitation with mating. Our results demonstrate that in the prairie vole, on the basis of the CPP in the testing conditions used here, the stimulation received with one ejaculation and the mating conditions that lead to pair bonding formation may be rewarding for males, and this reward state is opioid dependent.

Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease resistance. CS lines carrying small alien chromosome segments with favorable QTL alleles could be used for effective introgression of biotic stress resistance or many other desirable traits by targeting gene interactions and reducing linkage drag effects.

[Detection of serinocarbapenemases Class A and other mechanisms of enzymatic resistance to ß-lactams in enterobacteria strains with diminished susceptibility to carbapenems isolated of patients in a university hospital]. / Detección de serinocarbapenemasas de clase A y otros mecanismos de resistencia enzimática a ß-lactámicos en cepas de enterobacterias con susceptibilidad disminuida a carbapenémicos, aisladas de pacientes de un hospital universitario de Santiago, Chile.

BACKGROUND: The emergence of carbapenemase mediated resistance in Enterobacteriaceae has a strong clinical impact. This study aimed to do a genotypic and phenotypic characterization of the enzymatic resistance to ß-lactams in clinical Enterobacteriaceae isolates with decreased susceptibility to carbapenems in a university medical center in Santiago. METHODS: During April-September 2010 at Hospital Clinico Universidad de Chile, 23 isolates of carbapenem non susceptible Enterobacteriaceae were collected. We used PCR for the detection of class A carbapenemases (SME, IMI, NMC, GES and KPC) and the modified Hodge with the boronic acid test to phenotypically assess the presence of serine-carbapenemases. To assess extended spectrum ß-lactamases (ESBLs) the CLSI phenotypic tests were performed. Metallo-ß-lactamases (MBL) and AmpC were assessed with commercial tablets. RESULTS: 18/23 were Klebsiellapneumoniae and 5/23 strains were Enterobacter cloacae. All PCR to class A carbapenemases were negative. 3/23 strains (all E. cloacae), were positive to the Hodge modified test and 1/23, a K.pneumoniae, was positive to the boronic acid test. ESBLs were detected in 14/23 os the strains and AmpC in 5/23. No MBL was detected. CONCLUSION: No class A serine-carbapenemasa was detected. The decreased susceptibility to carbapenems is probably explained by the ß-lactamase activity and due to porin loss.

Co-infection patterns of infectious salmon anaemia and sea lice in farmed Atlantic salmon, Salmo salar L., in southern Chile (2007-2009).

Infectious salmon anaemia virus (ISAV) caused a large epidemic in farmed Atlantic salmon in Chile in 2007-2009. Here, we assessed co-infection patterns of ISAV and sea lice (SL) based on surveillance data collected by the fish health authority. ISAV status and SL counts in all Atlantic salmon farms located in the 10th region of Chile were registered monthly from July 2007 through December 2009. Each farm was categorized monthly according to its ISAV and SL status. A multinomial time-space scan test using a circular window was applied to identify disease clusters, and a multivariate regression model was fitted to quantify the association between disease-clustering and farm-management factors. Most of the identified clusters (9/13) were associated with high SL burdens. There were significant associations (P < 0.05) between management factors and ISAV/SL status. Areas in which good management practices were associated with a reduced disease risk were identified. The findings of this study suggest that certain management practices can effectively reduce the risk of SL and ISAV in the face of an epidemic and will be helpful towards creating an effective disease control programme in Chile.

[Antibiotic susceptibility patterns among Shigella sonnei, isolated during three different periods in Región Metropolitana, Chile]. / Patrones de susceptibilidad antimicrobiana de cepas de Shigella sonnei aisladas durante tres períodos diferentes en la Región Metropolitana, Chile.

BACKGROUND: Shigella sonnei gastroenteritis improves clinically and microbiologically with antibacterial treatment; however choosing a useful drug is a universal challenge because of in vitro susceptibility of S. sonnei frequently evolves to be resistant. OBJECTIVE: To evaluate in vitro susceptibility of S. sonnei strains isolated from patients attending at the Chilean Región Metropolitana and to know the evolution that resistant patterns of S. sonnei have experienced. MATERIAL: In this study, the antimicrobial susceptibility profile of 277 isolates of Shigella sonnei was compared. The analyzed periods of time were: period I (1995-1997) 85 strains; period II (2004-2006) 92 strains and period III (2008-2009) 100 strains, in Santiago, Chile. The method performed to analyze susceptibility patterns was the disc diffusion (Kirby-Bauer). RESULTS: The strains showed rates of resistance to ampicillin: period I, 85.8%; period II, 53.3%; period III, 100%, trimethoprim/sulfamethoxazole: period I, 50.5%; period, II 46.7%; period III, 100%, chloramphenicol: period I, 36.4%; period II, 12%; period III, 100% and tetracycline: period I, 38.8%; period II, 30.4%; period III, 100%. 98.9% of the strains showed susceptibility to quinolones. Significant differences were observed in patterns of antimicrobial resistance for both individuals and for multidrug resistance (≥ 3 antimicrobials) in the three periods (p < 0.001, χ2 test). Of all resistant strains, 17% were resistant to 1 or 2 antibiotics, while 65.7% showed a pattern of multidrug resistance; 100% of the period III strains presented multidrug resistance. CONCLUSION: These results showed the temporal resistance dynamics of S. sonnei circulating strains in the Chilean Región Metropolitana. Due to the endemic behavior of shigellosis in Chile, it is urgent to maintain permanent surveillance of antimicrobial resistance profiles to improve both prevention and treatment of shigellosis.

[Translated article] Immediate standing X-ray predicts the final vertebral collapse in elderly patients with thoracolumbar burst fracture.

OBJECTIVE: To see if, in elderly patients with traumatic thoracolumbar fracture, standing X-rays with orthoses 24-48h after admission can predict vertebral collapse after consolidation. MATERIAL AND METHODS: Prospective cohort study endorsed by the Clinical Research Ethics Committee. INCLUSION CRITERIA: age >65 years, acute thoracolumbar junction fracture due to fall, hospital admission, treatment with orthesis. EXCLUSION CRITERIA: various levels, suspected malignancy, non-immediate fracture or atraumatic. VARIABLES: Farcy index (F), regional kyphosis (C: Cobb from cranial to caudal to broken vertebra) - both measured at admission (F0 and C0), at 24-48h in standing position with orthesis (F1 and C1) and 3 months, without brace (F2 and C2), collapse (increase from F0 to F1 -F0F1- and from F1 to F2 -F1F2-; as well as from C0 to C1 -C0C1- and from C1 to C2 -C1C2-), age and gender. STATISTICAL ANALYSIS: R package. RESULTS: Series of 40 patients, with a mean age of 75 years (66-87). Nine men and 31 women. Neither gender nor age were correlated with any variable. Six required surgery at follow-up. There were no differences in F1, C1, F0F1 or C0C1 between the six patients who required surgery and the other 34. Subsequently, data analysis was performed only for those patients who did not require surgery. The values obtained in the Farcy index were 8°+7° (F0), 12°+7° (F1) and 15°+8° (F2) and in kyphosis (three vertebrae, Cobb) they were: C0=8°+13°; C1=11.5°+14° and C2=13°+13°. There was a correlation of F2 with F0 and F1 (p<.001), with F0F1 (p=.038) and F1F2 (p=.007). The most powerful was with F1 (Rho Spearman=.889, 95% CI=.776-.947), with a linear regression line: F2=2.61288+F1×1.01237 (R2=.79). C2 was correlated with C0 and C1 (p<.001), especially with C1 (Rho Spearman=.952, 95% CI=.899-.977). Linear regression: C2=2.23371+C1×0.93758 (R2=.927). CONCLUSIONS: Immediate standing collapse predicts alignment at consolidation (3 months). It is therefore advisable to perform that radiography in the follow-up protocol.

Immediate standing X-ray predicts the final vertebral collapse in elderly patients with thoracolumbar burst fracture. / La radiografía en bipedestación inmediata predice el colapso final de la vértebra fracturada en pacientes añosos con fractura estallido toracolumbar.

OBJECTIVE: To see if, in elderly patients with traumatic thoracolumbar fracture, standing X-rays with orthoses 24-48h after admission can predict vertebral collapse after consolidation. MATERIAL AND METHODS: Prospective cohort study endorsed by the Clinical Research Ethics Committee. INCLUSION CRITERIA: age >65 years, acute thoracolumbar junction fracture due to fall, hospital admission, treatment with orthesis. EXCLUSION CRITERIA: various levels, suspected malignancy, non-immediate fracture or atraumatic. VARIABLES: Farcy index (F), regional kyphosis (C: Cobb from cranial to caudal to broken vertebra) - both measured at admission (F0 and C0), at 24-48h in standing position with orthesis (F1 and C1) and 3 months, without brace (F2 and C2), collapse (increase from F0 to F1 -F0F1- and from F1 to F2 -F1F2-; as well as from C0 to C1 -C0C1- and from C1 to C2 -C1C2-), age and gender. STATISTICAL ANALYSIS: R package. RESULTS: Series of 40 patients, with a mean age of 75 years (66-87). Nine men and 31 women. Neither gender nor age were correlated with any variable. Six required surgery at follow-up. There were no differences in F1, C1, F0F1 or C0C1 between the six patients who required surgery and the other 34. Subsequently, data analysis was performed only for those patients who did not require surgery. The values obtained in the Farcy index were 8°+7° (F0), 12°+7° (F1) and 15°+8° (F2) and in kyphosis (three vertebrae, Cobb) they were: C0=8°+13°; C1=11.5°+14° and C2=13°+13°. There was a correlation of F2 with F0 and F1 (p<.001), with F0F1 (p=.038) and F1F2 (p=.007). The most powerful was with F1 (Rho Spearman=.889 (95% CI=.776-.947), with a Linear Regression line: F2=2.61288+F1×1.01237 (R2=.79). C2 was correlated with C0 and C1 (p<.001), especially with C1 (Rho Spearman=.952, 95% CI=.899-.977). Linear regression: C2=2.23371+C1×0.93758 (R2=.927). CONCLUSIONS: Immediate standing collapse predicts alignment at consolidation (3 months). It is therefore advisable to perform that radiography in the follow-up protocol.

A new multiplex PCR for differential identification of Shigella flexneri and Shigella sonnei and detection of Shigella virulence determinants.

Most of the multiplex PCR (mPCR) used to identify Shigella do not discriminate between Shigella species or serotypes. We designed a mPCR to differentiate between S. flexneri and S. sonnei strains based on the detection of markers associated with the she pathogenicity island described in Shigella. In addition, specific primers were included to detect the Shigella virulence determinants ShET-1 and ShET-2 enterotoxin genes. The analysis of 304 Shigella strains from Chile and 79 Shigella strains from other geographic locations indicated that the mPCR described here detected all Shigella species and specifically differentiated S. flexneri and S. sonnei. The technique was sensitive, reproducible, specific and simple to perform, providing a new tool with the potential to be employed for epidemiological and diagnostic purposes.

[Bacteremia caused by Vibrio cholerae non-O1/non-O139 carrying a region homologous to pathogenicity island VpaI-7]. / Bacteriemia por Vibrio cholerae no-O1/no-O139 que porta una región homóloga a la isla de patogenicidad VpaI-7.

We report a case of V. cholerae non-O1 / non-O139 bacteremia in an 81-year-old woman with abdominal pain, fever, vomiting, liquid stools, choluria and jaundice, while visiting a rural area without access to potable water. The identification was made by the MALDI-TOF mass spectrometry technique and subsequently the non-toxigenic non-O1 / non-139 strain was confirmed in the national reference laboratory. The molecular characterization demonstrated the absence of the cholera toxin gene (CTX), and the TCP pilus, however, presented 5 of 6 virulence genes present in an island of homologous pathogenicity named VPaI-7 of V. parahaemolyticus (vcs N2 +, vcs C2 +, vcs V2 +, toxR-, vspD +, T vopF +) and in addition it was positive for hylAy rtxA virulence genes recognized outside the island. This is the first case reported in Chile of a clinical strain of V. cholerae non-O1, non-O139 isolated from blood culture that carries in its genome a homologous segment of the pathogenicity island named VPaI-7 of V. parahaemolyticus, which codifies for a type III secretion system (TTSS) that probably contributes to his virulence.

Physiological and ultrastructural characterisation of a desiccation-tolerant filmy fern, Hymenophyllum caudiculatum: Influence of translational regulation and ABA on recovery.

The filmy fern Hymenophyllum caudiculatum can lose 60% of its relative water content, remain dry for some time and recover 88% of photochemical efficiency after 30 min of rehydration. Little is known about the protective strategies and regulation of the cellular rehydration process in this filmy fern species. The aim of this study was to characterise the filmy fern ultrastructure during a desiccation-rehydration cycle, and measure the physiological effects of transcription/translation inhibitors and ABA during desiccation recovery. Confocal and transmission electron microscopy were used to compare changes in structure during fast or slow desiccation. Transcription (actinomycin D) and translation (cycloheximide) inhibitors and ABA were used to compare photochemical efficiency during desiccation recovery. Cell structure was conserved during slow desiccation and rehydration, constitutive properties of the cell wall, allowing invagination and folding of the membranes and an important change in chloroplast size. The use of a translational inhibitor impeded recovery of photochemical efficiency during the first 80 min of rehydration, but the transcriptional inhibitor had no effect. Exogenous ABA delayed photochemical inactivation, and endogenous ABA levels decreased during desiccation and rehydration. Frond curling and chloroplast movements are possible strategies to avoid photodamage. Constitutive membrane plasticity and rapid cellular repair can be adaptations evolved to tolerate a rapid recovery during rehydration. Further research is required to explore the importance of existing mRNAs during the first minutes of recovery, and ABA function during desiccation of H. caudiculatum.

Anabolic androgenic steroids induce micronuclei in buccal mucosa cells of bodybuilders.

OBJECTIVE: To evaluate genotoxicity of anabolic androgenic steroids (AAS) in male bodybuilders by a micronucleus assay in buccal mucosa cells. METHODS: 11 male bodybuilders volunteered to participate in this study and two groups were formed: group 1 (n = 6), without AAS consumption and group 2 (n = 5), with AAS consumption. A sample of buccal epithelium was taken from each participant once a week for 6 weeks. Samples were fixed, stained and analysed by a light microscope, and 2000 cells were counted from each slide. Results are expressed as micronucleated cells (MNC) per 1000 cells and were analysed by the Mann-Whitney U test and Wilcoxon's test. RESULTS: A marked increased in MNC was seen in bodybuilders with AAS consumption compared with those without AAS consumption (mean (SD) 4.1 (2.4) MNC/1000 cells vs 0.4 (0.4) MNC/1000 cells, respectively; p<0.004). Intragroup comparisons showed no differences in the MNC frequencies during the sampling time in group 1, whereas the MNC frequency in group 2 varied significantly, reaching the highest MNC frequencies in the third and fourth week of sampling (5.9 (2.4) MNC/1000 cells; 5.8 (1.8) MNC/1000 cells, respectively); frequency in the first sampled week was 1.1 (0.1) MNC/1000 cells. Significant differences in all sampled weeks were found between the two groups. CONCLUSION: AAS consumption increased the frequency of MNC from buccal mucosa in bodybuilders.

Proximal sacral deformity: a common element in lytic isthmic spondylolisthesis at L5 and in degenerative spondylolisthesis at L4-L5 segment. Two apparently very different etiopathogenic entities. / Deformidad sacra proximal: elemento común a la espondilolistesis ístmica lítica de L5 y a la degenerativa del segmento L4-L5, 2 entidades de etiopatogenia muy diferente, aparentemente.

A radiographic study was carried out to investigate the relationship between proximal sacral sagittal anatomy (either kyphosis or lordosis) and either isthmic or degenerative spondylolisthesis. In addition, we studied whether there is a relationship between proximal sacral kyphosis and the degree of such listhesis in the case of L5 isthmic spondylolisthesis. Lateral standing x-rays were used from 173 patients, ninety of whom had degenerative spondylolisthesis L4-L5, and eighty-three an isthmic spondylolisthesis of L5 (67 low-grade and 16 high-grade) and compared with a control group of 100 patients adjusted by age and gender, without any type of spondylolisthesis. Listhesis was graded using Meyerding's classification and the proximal sacral kyphosis angle (CSP) was measured between S1 and S2 posterior walls, according to Harrison's method. In our series, there was a proximal sacral kyphosis in both types of spondylolisthesis, greater in the lytic type. By contrast, the control group had a proximal sacral lordosis. The differences were statistically significant. Therefore, we concluded that there was a proximal sacral kyphosis in patients with both degenerative and isthmic lytic spondylolisthesis, but with our results, we were not able to ascertain whether it is a cause or a consequence of this listhesis.

Lordosis manoeuvre in the diagnosis of lumbar facet syndrome. / Efectividad de la maniobra lordosante en el diagnóstico del síndrome facetario lumbar.

UNLABELLED: In lumbar pain patients an aetiopathogenic diagnosis leads to a better management. When there are alarm signs, they should be classified on an anatomical basis through anamnesis and physical examination. A significant group is of facet origin (lumbar facet syndrome [LFS]), but the precise clinical diagnosis remains cumbersome and time-consuming. In clinical practice it is observed that patients with an advanced degenerative disease do not perform extension or rotation of their lumbar spine when prompted to extend it, but rather knee flexion, making the manoeuvre meaningless. For this reason, a new simple and quick clinical test was developed for the diagnosis of lumbar facet syndrome, with a facet block-test as a confirmation. HYPOTHESIS: The new test is better than a classic one in the diagnosis of facet syndrome, and probably even better than imaging studies MATERIALS AND METHODS: A prospective study was conducted on a series of 68 patients (01/01/2012-30/06/2013). A comparison in between: classic manoeuvre (CM), imaging diagnostics (ID), and the new lordosis manoeuvre (LM) test. Examination and block test by one author, and evaluation of results by another one. EXCLUSION CRITERIA: Deformity and instability. using a physical. OBJECTIVE: To determine the effectiveness of a new clinical test (LM) for the diagnosis of LFS (as confirmed by a positive block-test of medial branch of dorsal ramus of the lumbar root, RMRDRL). STATISTICS: R package software. RESULTS: The LM was most effective (p<.0001; Kappa 0.524, p<.001). There was no correlation between either the CM or ID and the block-test results (Kappa, CM: 0.078; p=.487, and ID: 0.195; p=.105). There was a correlation between ID (CAT/MR) and LM (p=.024; Kappa 0.289 p=.014), although not with CM. There was no correlation between ID (plain X-rays) and CM or LM. CONCLUSIONS: A new test for diagnosis of LFS is presented that is reliable, quick, and simple. Clinical examination is more reliable than imaging test for the diagnosis of LFS.

Prognostic value of an immediate lateral standing X-ray with a TLSO in patients with a thoracolumbar burst fracture.

UNLABELLED: The final collapse of a "stable" thoracolumbar burst fracture is difficult to predict. This collapse was prospectively studied radiologically in patients with T12 or L1 burst fractures who, after evaluating the admission x-rays and the CT scan with the patients themselves, opted for a rigid thoracolumbar brace with support in the sternal manubrium (TLSO). On the other hand, patients with rigid braces sometimes have low back pain on follow-up (due to overload of the L5-S1 joints). HYPOTHESIS: the standing lateral x-ray with only a TLSO for support (intrinsic mechanical stability) provides information on the final collapse and could also provide information on the low back pain. The study included 50 patients (20 males and 30 females, age: 63+14 years) admitted during 2011 and 2012, with 2 losses to follow-up. VARIABLES: Farcy index and local kyphosis (Cobb at 3 vertebrae). X-Rays: admission, with TLSO (immediate: Rx0), and at 3 and 6 months. They were compared with the final clinical and radiological results. It was decided to surgically intervene in 4 patients after Rx0. There were no painful sequelae at the fracture level, and 16/44 (31%) had low back pain. Using linear regression mathematical models, the increase in the Farcy index (Rx0-Rx admission) was associated with the appearance of low back pain and with local kyphosis (Rx0-Rx admission), and with the final kyphosis. It is advisable to perform a lateral standing X-ray after TLSO for information on the final collapse of the fracture and the appearance of accompanying low back pain.

Making strides towards better mental health care in Peru: Results from a primary care mental health training.

Our program attempted to improve attitudes and confidence of Peruvian primary care physicians (PCPs) providing mental health care. The training program underwent an evaluation to determine impact of sustained confidence in performing medical and psychiatric procedures, and application of learned skills. Fifty-two Peruvian primary care practitioners were trained at the Harvard Program in Refugee Trauma (HPRT) over a two-week period. There was significant improvement in PCPs' confidence levels of performing psychiatric procedures (counseling, prescribing medications, psychiatric diagnosis, assessing the risk for violence, and treating trauma victims) when comparing baseline and post-two-week to one year follow-up. When comparing post-two-week and one-year follow-up quantitative measures, confidences levels went slightly down. This may be an implication that the frequency of trainings and supervisions are needed more frequently. In contrast, qualitative responses from the one-year follow-up revealed increase in victims of violence clinical care, advocacy, awareness, education, training, policy changes, accessibility of care, and sustainment of diagnostic tools. This study supports the feasibility of training PCP's in a culturally effective manner with sustainability over time.

SPECT, magnetic resonance and angiographic features in a moyamoya patient before and after external-to-internal carotid artery bypass.

Brain SPECT changes in a patient with cerebral vaso-occlusive disease caused by moyamoya disease are presented. Brain SPECT after a revascularization procedure demonstrated significant improvement of brain flow which was confirmed by angiography. Clinical and magnetic resonance features are reviewed.

Are oral cathartics of value in optimizing the gallium scan? Concise communication.

The normal intestinal secretion of 9-15% of an administered dose of gallium-67 may prevent early detection of intra-abdominal disease. We randomized 50 patients to receive either no bowel preparation or 30 cc of milk of magnesia plus 5 cc of cascara. No significant difference was found between the two groups in frequency with which gallium interfered with readings or time to complete the study.

Bone imaging in infections: artefacts from spectral overlap between a Tc-99m tracer and In-111 leukocytes.

In three patients with skeletal infectious disease, scintigrams with a Tc-99m bone-seeker and In-111-tagged leukocytes, made within 24 hr of each other, showed striking similarities. In two cases, the findings from the In-111 WBC images were ultimately determined to be artefacts due to Tc-99m crosstalk within the 173-keV photopeak of In-111. In the second case, the error was traced to failure to use a pure In-111 source for energy calibration: the camera had been peaked on the radiation from the patient himself, who had had an earlier Tc-99m bone scan.

Skeletal photopenic lesions in In-111 WBC imaging.

Four cases of skeletal photon-deficient areas in In-111 white blood cell (In-111 WBC) images are reported. These were found in patients with lymphoma, vertebral osteomyelitis, and following radiotherapy and extensive surgical procedures. We emphasize that these photopenic lesions, although uncommon, may represent tumor involvement or benign processes, including osteomyelitis. Possible mechanisms to explain this phenomenon are discussed.

Diagnosis of segmental necrosis in a pancreas transplant by thallium-201 perfusion scintigraphy.

Thallium-201 was used to image a patient with a pancreatic transplant. Incomplete visualization of the graft on the 201Tl scan, compared to CT, led to the diagnosis of segmental necrosis of the tail of the graft. Due to the low background and favorable target-to-non-target ratio, 201Tl pancreas scintigraphy may be useful in the follow-up of pancreatic transplants.