Theory of mind in neurodevelopmental disorders: beyond autistic spectrum disorder

INTRODUCTION

Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group.

METHODS

Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n = 19), TS (n = 14), or ASD (n = 18), and a control group (n = 20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the "Stories from everyday life" task and the "Reading the mind in the eyes" test).

RESULTS

Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls.

CONCLUSIONS

ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS.

Deep-learning-based attenuation correction in dynamic [15O]H2O studies using PET/MRI in healthy volunteers

Quantitative [¹⁵O]H₂O positron emission tomography (PET) is the accepted reference method for regional cerebral blood flow (rCBF) quantification. To perform reliable quantitative [¹⁵O]H₂O-PET studies in PET/MRI scanners, MRI-based attenuation-correction (MRAC) is required. Our aim was to compare two MRAC methods (RESOLUTE and DeepUTE) based on ultrashort echo-time with computed tomography-based reference standard AC (CTAC) in dynamic and static [¹⁵O]H₂O-PET. We compared rCBF from quantitative perfusion maps and activity concentration distribution from static images between AC methods in 25 resting [¹⁵O]H₂O-PET scans from 14 healthy men at whole-brain, regions of interest and voxel-wise levels. Average whole-brain CBF was 39.9 ± 6.0, 39.0 ± 5.8 and 40.0 ± 5.6 ml/100 g/min for CTAC, RESOLUTE and DeepUTE corrected studies respectively. RESOLUTE underestimated whole-brain CBF by 2.1 ± 1.50% and rCBF in all regions of interest (range -2.4%- -1%) compared to CTAC. DeepUTE showed significant rCBF overestimation only in the occipital lobe (0.6 ± 1.1%). Both MRAC methods showed excellent correlation on rCBF and activity concentration with CTAC, with slopes of linear regression lines between 0.97 and 1.01 and R² over 0.99. In conclusion, RESOLUTE and DeepUTE provide AC information comparable to CTAC in dynamic [¹⁵O]H₂O-PET but RESOLUTE is associated with a small but systematic underestimation.

Theory of mind in neurodevelopmental disorders: Beyond autistic spectrum disorder

INTRODUCTION

Theory of mind (ToM) is the human ability to perceive, interpret, and attribute the mental states of other people, and the alteration of this cognitive function is a core symptom of autistic spectrum disorder (ASD). In such other neurodevelopmental disorders as childhood-onset obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) that can present with cognitive dysfunctions, ToM has been less extensively studied, especially in the young population. The aim of the study was to compare advanced ToM between groups of young people diagnosed with OCD, TS, or ASD and a control group.

METHODS

Clinical interviews were conducted with male patients aged between 11 and 17 years with a main diagnosis of OCD (n=19), TS (n=14), or ASD (n=18), and a control group (n=20). We administered instruments for estimating intelligence quotient and severity of psychiatric symptoms, and tasks to evaluate ToM (the "Stories from everyday life" task and the "Reading the mind in the eyes" test).

RESULTS

Young people with TS and with ASD present similar difficulties in solving advanced ToM tasks, whereas patients with childhood-onset OCD present similar results to controls.

CONCLUSIONS

ToM is altered in other neurodevelopmental disorders beyond ASD, such as TS.

Comparison of simultaneous arterial spin labeling MRI and 15O-H2O PET measurements of regional cerebral blood flow in rest and altered perfusion states

Arterial spin labelling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that may provide fully quantitative regional cerebral blood flow (rCBF) images. However, before its application in clinical routine, ASL needs to be validated against the clinical gold standard, ¹⁵O-H₂O positron emission tomography (PET). We aimed to compare the two techniques by performing simultaneous quantitative ASL-MRI and ¹⁵O-H₂O-PET examinations in a hybrid PET/MRI scanner. Duplicate rCBF measurements were performed in healthy young subjects (n = 14) in rest, during hyperventilation, and after acetazolamide (post-ACZ), yielding 63 combined PET/MRI datasets in total. Average global CBF by ASL-MRI and ¹⁵O-H₂O-PET was not significantly different in any state (40.0 ± 6.5 and 40.6 ± 4.1 mL/100 g/min, respectively in rest, 24.5 ± 5.1 and 23.4 ± 4.8 mL/100 g/min, respectively, during hyperventilation, and 59.1 ± 10.4 and 64.7 ± 10.0 mL/100 g/min, respectively, post-ACZ). Overall, strong correlation between the two methods was found across all states (slope = 1.01, R²= 0.82), while the correlations within individual states and of reactivity measures were weaker, in particular in rest (R²= 0.05, p = 0.03). Regional distribution was similar, although ASL yielded higher perfusion and absolute reactivity in highly vascularized areas. In conclusion, ASL-MRI and ¹⁵O-H₂O-PET measurements of rCBF are highly correlated across different perfusion states, but with variable correlation within and between hemodynamic states, and systematic differences in regional distribution.

Usefulness of HMPAO-SPECT in the diagnosis of nonconvulsive status epilepticus

BACKGROUND

The diagnosis of nonconvulsive status epilepticus (NCSE) can pose a challenge. Electroencephalogram (EEG) patterns can be difficult to interpret, and the absence of an EEG correlate does not rule out the diagnosis of NCSE. In this setting, neuroimaging tools to help in the diagnosis are crucial. Our aim was to evaluate the role of 99mTc-hexamethyl propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) and quantitative HMPAO-SPECT (QtSPECT) in patients with clinical suspicion of NCSE, and to evaluate their value in the final diagnosis of NCSE.

METHODS

We recruited consecutive patients admitted in our center with suspicion of NCSE, and selected those who underwent an HMPAO-SPECT. All patients were admitted to the neurology ward and underwent an EEG. We divided the patients into those who were finally with diagnosed NCSE (NCSE-p) and those who were not (non-NCSE) according to the Salzburg Diagnostic EEG criteria. Sensitivity and specificity of the diagnostic tools were calculated. The SPECTs were acquired in a Skylight SPECT (Philips Healthcare, Amsterdam). The injections were done during the clinical episode suspected of being an NCSE. The HMPAO-SPECT was analyzed by two experts and was also quantified. All data were normalized to the SPM SPECT template. We used an external healthy normal database to obtain a Z-score map for each individual versus the normal database. The Z-score maximum (Z_max) was extracted from each region of the AAL atlas as was the percentage of voxels with a Z-score higher than 2.5 (N(%)). A logistic regression combining the Z_max, N(%), and the effect of patient age was fitted to predict the final NCSE diagnosis. A receiver operator characteristic (ROC) curve and the area under the curve (AUC) were obtained to evaluate the classification performance.

RESULTS

We included 55 patients, 21 of them women (38.9%), with a median age of 62.1 years old (range 25-84). Thirty-six patients were with diagnosed NCSE (62.9%). Initial EEG had a sensitivity of 61.1% and a specificity of 89%. Most of the patients were critically ill with diagnostic difficulties, and it could be one of the main reasons to find low sensitivity of the Salzburg diagnostic EEG criteria. The Z_max and N(%) were significantly higher in NCSE-p than in non-NCSE (p = 0.005 and p < 0.001, respectively). The HMPAO-SPECT qualitative analysis had a sensitivity of 80.5% and specificity of 89.5% while QtSPECT had a sensitivity of 82% and specificity of 81%.

CONCLUSION

Both 99mTc-HMPAO-SPECT and QtSPECT can be useful in the diagnosis of NCSE. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

Phase contrast mapping MRI measurements of global cerebral blood flow across different perfusion states - A direct comparison with 15O-H2O positron emission tomography using a hybrid PET/MR system

Phase-contrast mapping (PCM) magnetic resonance imaging (MRI) provides easy-access non-invasive quantification of global cerebral blood flow (gCBF) but its accuracy in altered perfusion states is not established. We aimed to compare paired PCM MRI and 15O-H2O positron emission tomography (PET) measurements of gCBF in different perfusion states in a single scanning session. Duplicate combined gCBF PCM-MRI and 15O-H2O PET measurements were performed in the resting condition, during hyperventilation and after acetazolamide administration (post-ACZ) using a 3T hybrid PET/MR system. A total of 62 paired gCBF measurements were acquired in 14 healthy young male volunteers. Average gCBF in resting state measured by PCM-MRI and 15O-H2O PET were 58.5 ± 10.7 and 38.6 ± 5.7 mL/100 g/min, respectively, during hyperventilation 33 ± 8.6 and 24.7 ± 5.8 mL/100 g/min, respectively, and post-ACZ 89.6 ± 27.1 and 57.3 ± 9.6 mL/100 g/min, respectively. On average, gCBF measured by PCM-MRI was 49% higher compared to 15O-H2O PET. A strong correlation between the two methods across all states was observed (R2 = 0.72, p < 0.001). Bland-Altman analysis suggested a perfusion dependent relative bias resulting in higher relative difference at higher CBF values. In conclusion, measurements of gCBF by PCM-MRI in healthy volunteers show a strong correlation with 15O-H2O PET, but are associated with a large and non-linear perfusion-dependent difference.

Evaluating Sex and Age Differences in ADI-R and ADOS Scores in a Large European Multi-site Sample of Individuals with Autism Spectrum Disorder

Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and repetitive behaviours were lower in females than males, alongside comparable levels of social interaction and communication difficulties in females and males. Current ADI-R and ADOS scores showed no sex differences for ASD severity. There were lower socio-communicative symptoms in older compared to younger individuals. This large European ASD sample adds to the literature on sex and age variations of ASD symptomatology.

Refractory status epilepticus due to SMART syndrome

INTRODUCTION

Stroke-like migraine attacks after radiation therapy (SMART) is a late-onset complication of brain irradiation of unknown physiopathology. Our aim was to present three patients with SMART syndrome who had clinical and neuroimage studies suggestive of status epilepticus.

PATIENTS

Patient 1. A 69-year-old woman, who was treated with radiation therapy 14 years before her first admission to the Neurology Department, presented with several episodes of headache, speech disturbances, and weakness of left limbs with altered awareness. Patient 2. A 49-year-old man, who was treated with whole brain radiation 20 years before the onset of symptoms, developed some episodes consisting of headache and numbness of the right side of face and right arm; the latest episodes were accompanied by visual disturbances followed by generalized tonic-clonic seizures. Patient 3. A 40-year-old man, who received cranial irradiation 20 years before, suffered three episodes of behavioral disturbance, aphasia, headache, and visual aura followed by left homonymous hemianopia.

RESULTS

All three patients suffered seizures mostly with visual aura. Electroencephalography showed interictal epileptiform discharges or focal slowing. Brain magnetic resonance image (MRI), positron emission tomography (PET), or ictal-single-photon emission computed tomography (SPECT) showed focal cortical hyperperfusion. Focal diffusion restriction and focal gadolinium-enhancement were observed on MRI. All patients were treated with antiepileptic drugs, being effective in one of them. One patient needed anesthesic coma, and the other patient responded to therapy with corticosteroids.

CONCLUSIONS

Taking into account clinical evolution and ictal neuroimaging studies, status epilepticus could explain the origin of these episodes in SMART syndrome. Although most patients have reversible symptoms, in some cases, aggressive treatment to avoid sequelae is needed. This article is part of a Special Issue entitled "Status Epilepticus".

Laparoscopic repair of non-complicated lumbar hernia secondary to a latissimus dorsi flap

Lumbar hernia is an unusual complication of the latissimus dorsi flap. Traditionally, it has always been repaired using open-surgery techniques. We present the first description of laparoscopic surgery to treat a non-complicated superior lumbar hernia resulting from the creation of an enlarged latissimus dorsi myocutaneous flap for breast reconstruction following left modified radical mastectomy. The laparoscopic approach substantially reduced the risks associated with open surgery, shortened length of hospital stay and time to recovery and obtained better cosmetic results. Laparoscopic surgery may be considered as a feasible therapeutic option for non-complicated superior lumbar hernias secondary to a latissimus dorsi muscle flap.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Assessment of real-world daily-living skills in early-onset schizophrenia trough the Life Skills Profile scale

BACKGROUND

Adolescents with early-onset schizophrenia (EOS) have marked deficits in their functional outcome. However, few short and reliable instruments for assessing real-world functioning have been specifically validated in EOS. The Life Skills Profile (LSP) is a brief scale widely used in schizophrenia and considered one of the optimal instruments for assessing real-world daily living skills. The purpose of this study was to examine the usefulness and the feasibility of the LSP to assess daily living skills in EOS.

METHODS

The sample included 53 clinically and pharmacologically stabilized adolescent patients with EOS and 53 healthy adolescents. Content review of the scale and internal consistency analysis were conducted in the EOS group. A subgroup of 30 patients was re-assessed over a 10-day interval to establish the test-retest reliability. Measures of functional outcome were used to assess convergent validity, and measures of intelligence and symptoms were used to assess divergent validity. Discriminant validity was analyzed through logistic analysis and the receiver-operating characteristic curve.

RESULTS

The LSP and its subscales showed high reliability, adequate internal consistency and adequate convergent and divergent validity. The LSP was also found to be a sensitive instrument for detecting differences between patients and healthy adolescents, correctly classifying 84% of the sample. The estimated area under the curve was 0.925 (95% CI 0.875-0.976).

CONCLUSIONS

The LSP showed adequate psychometric characteristics in adolescents with EOS and appeared to be a valid, reliable and time-efficient instrument for use in clinical practice and research settings to assess real-world daily-living skills in EOS.

Location of aortic node metastases in locally advanced cervical cancer

BACKGROUND

To assess the location of aortic node metastasis in patients with locally advanced cervical cancer undergoing extraperitoneal aortic lymphadenectomy to define the extent of the aortic lymphadenectomy.

MATERIAL AND METHODS

Between August 2001 and December 2010, 100 consecutive patients with primary locally advanced cervical cancer underwent extraperitoneal laparoscopic aortic and common iliac lymphadenectomy. The location of aortic node metastases, inframesenteric or infrarenal was noted.

RESULTS

The mean number±standard deviation (SD) of aortic nodes removed was 15.9 ± 7.8 (range 4-62). The mean number ± SD of inframesenteric (including common iliac) nodes removed was 8.8 ± 4.5 (range 2-41) and the mean number ± SD of infrarenal nodes removed was 7.8 ± 4.1 (range 2-21). Positive aortic nodes were observed in 16 patients, and in 5 (31.2%) of them the infrarenal nodes were the only nodes involved, with negative inframesenteric nodes.

CONCLUSION

Inframesenteric aortic nodes are negative in the presence of positive infrarenal nodes in about one third of patients with locally advanced cervical cancer and aortic metastases.

Modified approach for extraperitoneal laparoscopic staging for locally advanced cervical cancer

Describe a modified approach to the technique for staging laparoscopic extraperitoneal aortic and common iliac lymph node dissection for locally advanced cervical cancer.Retrospective, nonrandomized clinical study. (Canadian Task Force classification II-2), setting in an acute-care, teaching hospital. Thirty-six patients with locally advanced cervical cancer underwent laparoscopic surgical staging via extraperitoneal approach with the conventional or the modified technique from August 2001 through September 2004. Clinical outcomes in 23 patients who were operated on with the conventional technique using index finger for first trocar entrance; 12 patients with the modified technique using direct trocar entrance, were compared. One patient was excluded due to peritoneal carcinomatosis. Technique, baseline characteristics, histopathologic variables and surgical outcome were measured. There were no significant differences in patients basal characteristics on comparative analysis between conventional and modified technique. With our proposed modified technique, we obtained a reduced surgical procedure duration and blood loss. The proposed modified surgical technique offers some advantages, is an easier approach because the parietal pelvic peritoneum is elastic and this helps to avoid its disruption at time of trocar insertion, size of incision is shorter, we achieved no CO2 leak through the trocar orifice, and wound suture is fast and simple.

[Gender differences in cognitive functions and influence of sex hormones]

OBJECTIVE

To review scientific evidence on gender differences in cognitive functions and influence of sex hormones on cognitive performance.

METHOD

Systematical search of related studies identified in Medline.

RESULTS

Women outperform men on verbal fluency, perceptual speed tasks, fine motor skills, verbal memory and verbal learning. Men outperform women on visuospatial ability, mathematical problem solving and visual memory. No gender differences on attention and working memory are found. Researchers distinguish four methods to investigate hormonal influence on cognitive performance: a) patient with hormonal disorders; b) neuroimaging in individuals during hormone administration; c) in women during different phases of menstrual cycle, and d) in patients receiving hormonal treatment (idiopathic hypogonadotropic hypogonadism, postmenopausal women and transsexuals). The findings mostly suggest an influence of sex hormones on some cognitive functions, but they are not conclusive because of limitations and scarcity of the studies.

CONCLUSIONS

There are gender differences on cognitive functions. Sex hormones seem to influence cognitive performance.

Total laparoscopic radical trachelectomy with intraoperative sentinel node identification for early cervical stump cancer

A 60-year-old patient had undergone a subtotal hysterectomy through a standard laparotomy approach due to multiple uterine myomas 6 years before. She had a 1-month history of postmenopausal uterine bleeding. An endocervical polyp was found and excised. The histopathologic examination showed a poorly differentiated adenocarcinoma. Magnetic resonance imaging of the abdomen and pelvis revealed the mass (4x2x2.5 cm) without parametrial involvement previously identified on vaginal examination. There was no retroperitoneal adenopathy. The patient was successfully treated with total laparoscopic radical trachelectomy in association with laparoscopic intraoperative detection of the sentinel lymph node.

Total laparoscopic radical hysterectomy (type II-III) with pelvic lymphadenectomy in early invasive cervical cancer

STUDY OBJECTIVE

To describe the feasibility and outcome of total laparoscopic radical hysterectomy with pelvic lymphadenectomy in early cervical cancer.

DESIGN

Retrospective, nonrandomized study (Canadian Task Force classification II-2).

SETTING

Acute-care, teaching hospital.

PATIENTS

Twenty-seven nonconsecutive patients with International Federation of Gynecology and Obstetrics (FIGO) stage IA2 (n = 4) or IB1 (n = 23) cancer of the cervix.

INTERVENTION

Laparoscopic type II (n = 9) or type III (n = 18) hysterectomy with systematic bilateral pelvic lymphadenectomy. Monopolar coagulation, vascular clips, and harmonic scalpel were used. Resection of the cardinal and uterosacral ligaments was performed with Endo GIA stapling and the harmonic scalpel.

MEASUREMENTS AND MAIN RESULTS

Histopathologically, there were 20 cases of squamous carcinoma, 6 adenocarcinomas, and 1 adenosquamous carcinoma. The operation was performed entirely by laparoscopy in 26 patients. One patient underwent laparotomy because of equipment failure. The patients' mean age was 45.1 years (95% CI 41.7-48.4), with a median body mass index of 26.0 kg/m2. The mean number of resected pelvic nodes was 19.1 (95% CI 17.02-21.2). Three patients had microscopic metastatic nodal disease. The surgical margins were free of disease in all cases. The median blood loss was 400 mL (range 250-700 mL). The median length of stay was 5 days. Major intraoperative complications did not occur. All patients are free of disease after a median follow-up of 32 months (range 4-52 months).

CONCLUSION

Radical hysterectomy can be successfully completed by laparoscopy in patients with early cervical cancer. This procedure may reduce the morbidity associated with abdominal or transvaginal radical hysterectomy.

Total laparoscopic radical hysterectomy with intraoperative sentinel node identification in patients with early invasive cervical cancer

OBJECTIVES

To describe the feasibility and results of total laparoscopic radical hysterectomy with intraoperative sentinel lymph node identification in patients with early cervical cancer.

METHODS

Between March 2001 and October 2003, 12 patients with FIGO stage IA(2) (n = 1) or IB(1) (n = 11) cancer of the cervix underwent surgical treatment through the laparoscopic route. All patients underwent a laparoscopic sentinel node identification with preoperative lymphoscintigraphy (technetium-99 m colloid albumin injection around the tumor) and intraoperative lymphatic mapping with isosulfan blue dye and a laparoscopic gamma probe followed by systematic bilateral pelvic lymphadenectomy and laparoscopic type II (n = 5) or type III (n = 7) hysterectomy.

RESULTS

A mean of 2.5 sentinel nodes per patient (range 1-4) was detected, with a mean of 2.33 nodes per patient by gamma probe and a mean of 2 per patient after blue injection (combined detection rate 100%). The most frequent localization of the nodes was the interiliac region. Histopathologic examination of sentinel nodes including cytokeratin immunohistochemical analysis did not show metastasis. Microscopic nodal metastases were not found. The mean number of resected pelvic nodes was 18.6 per patient (range 10-28). The operation was performed entirely by laparoscopy in all patients and no case of laparotomy conversion was recorded. The mean duration of operation was 271 min (range 235-300), with a mean blood loss of 445 mL (range 240-800), and a mean length of stay of 5.25 days (range 3-10). No major intraoperative complications occurred. After a median follow-up of 20 months (range 5-34), all patients are free of disease.

CONCLUSIONS

This study shows the feasibility of the combination of laparoscopic intraoperative sentinel node mapping and laparoscopic radical surgery in the context of minimally invasive surgery for the management of patients with early cervical cancer.

Temporal trends of PCDDs/PCDFs in ambient air in Catalonia (Spain)

This paper reports the results of an assessment of dioxin levels in ambient air in samples collected in the four provinces of Catalonia (Spain) performed by the Environment Department of the Autonomous Government of Catalonia and the Spanish Council for Scientific Research (CSIC). The study includes compiled data of more than 133 samples collected in 28 different sites (rural, urban, suburban and industrial) between 1994 and 2002. The levels revealed a variable content of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) depending both on the area and the contamination source. Thus, concentrations from 16 to 954 fg I-TEQ/Nm(3), with a mean value of 180 fg I-TEQ/Nm(3), were determined in industrial areas. The levels found in urban and suburban sites varied from 10 to 357 fg I-TEQ/Nm(3), with a mean value of 80 fg I-TEQ/Nm(3). The lowest concentrations were found in rural areas, ranging from 5 to 125 fg I-TEQ/Nm(3), with a mean value of 42 fg I-TEQ/Nm(3). As part of the project, levels of samples collected in parallel using two different samplers, a total suspended particulate (TSP) sampler and PM10 sampler, were compared. The results of 11 different campaigns indicated that both methods are comparable and no significant differences were determined.

Surveillance programme on dioxin levels in ambient air sites in Catalonia (Spain)

As part of a survey programme conducted by the Environment Department of the Autonomous Government of Catalonia in collaboration with the Spanish Council for Scientific Research (CSIC), dioxin concentrations in ambient air were measured in the four provinces of Catalonia (Spain). The study was also performed with the intention of providing data as a basis for future monitoring and evaluation of temporal trends in ambient air. Thus, 91 samples were collected in 25 different sites (rural, urban, suburban and industrial) between 1994 and 2000. The levels revealed a variable content of PCDDs/PCDFs depending both on the area and the contamination source. In particular, industrial areas presented levels ranging from 18 to 954 fg I-TEQ/m3. However, findings in urban and suburban sites varied between 13 and 357 fg I-TEQ/m3. As expected, the lowest levels were found in rural areas with levels between 5 and 125 fg I-TEQ/m3.

Low fusion rate after L5-S1 laparoscopic anterior lumbar interbody fusion using twin stand-alone carbon fiber cages

STUDY DESIGN

Prospective study of a cohort of patients who underwent L5-S1 laparoscopic anterior lumbar interbody fusion.

OBJECTIVES

To assess the fusion rate and the clinical outcome more than 2 years after L5-S1 laparoscopic anterior lumbar interbody fusion using twin stand-alone carbon-fiber cages.

SUMMARY OF BACKGROUND DATA

The first reports on laparoscopic anterior lumbar interbody fusion using stand-alone cages appeared in 1995. Since then several articles have reported contradictory data regarding fusion rate. There are no publications describing the fusion rate of stand-alone lumbar carbon-fiber cages.

METHODS

The authors evaluated 12 patients (mean age 36.5 years) in whom endoscopic L5-S1 anterior lumbar interbody fusion was performed using twin stand-alone laparoscopic carbon-fiber cages. Clinical evaluation was carried out prospectively by the use of three self-evaluation scales. Radiologic evaluation was performed by an independent radiologist using dynamic flexion-extension films and CT scans at 6 and 12 months after surgery and subsequently every year until fusion was demonstrated.

RESULTS

After a mean follow-up of 36.6 months (range 24-63 months) the clinical condition of the patients was significantly better than their preoperative status: visual analog scale (P < 0.01), Prolo score (P < 0.05), and Waddell Disability Index (P < 0.01). L5-S1 mobility did not exceed 5 degrees in any dynamic study. However, the overall CT scan fusion rate at 2 years of follow-up was 16.6%. Three years after surgery, CT demonstrated fusion in one of five patients.

CONCLUSION

Two years after endoscopic L5-S1 anterior lumbar interbody fusion using twin stand-alone laparoscopic carbon-fiber cages, the fusion rate was unacceptably low. However, the clinical outcomes of these patients were significantly improved compared with their preoperative status.

Characterization of enteroaggregative Escherichia coli strains isolated from children with acute diarrhea, in Mendoza, Argentina

Enteroaggregative Escherichia coli (EAEC) is an increasingly recognized cause of diarrhea in children in developing and developed countries. EAEC is recognized by a characteristic aggregative pattern of adherence to human epithelial (HEp-2) cells cultured in vitro. This is the gold standard assay. The aggregative phenotype is associated with the presence of a 65 MDa plasmid (pAA) that also encodes several other putative virulence factors, such as the aggregative adherence fimbria I (AAF/I) and the enteroaggregative heat-stable enterotoxin (EAST1). The objective of this work was to evaluate the application of PCR (polymerase chain reaction) to identify EAEC strains in cases of acute diarrhea. A total of 87 E. coli strains, isolated from patients under 2 years of age with acute diarrhea in Mendoza, Argentina, were characterized by the reference method (HEp-2 assay), and by AAF/I- and EAST1-PCR. PCR sensitivity and specificity in comparison with the cell culture assay showed 94.4% sensitivity and 78.26% specificity. EAST1- and AAF/I-PCR could be recommended as a screening test, applicable to epidemiologic studies.

Molecular genetics of familial hypercholesterolemia in Spain: Ten novel LDLR mutations and population analysis

Mutations underlying FH in Spain are largely unknown because only a few and limited surveys have been carried out on Spanish FH patients up to now. To gain information on this issue, we have analysed a group of 113 unrelated Spanish FH patients from an eastern area of Spain (Valencian Community). We have screened the LDLR gene by Southern blot and PCR-SSCP analysis to detect large rearrangements and small mutations, respectively. In addition, we have screened the Apo B gene for mutations known to cause FDB by PCR-SSCP analysis. We have identified a total of 47 different mutations in the LDLR gene (5 large rearrangements, and 42 small mutations, which were characterized by DNA sequencing), 19 of which have not been described in other populations (Valencia-1 to -4, 112insA, P160R, 790DelATGA, 920insTCAG, G642E, and the ten novel mutations E246A, 884delT, I289T, S305F, Q328X, Y354C, I603del, 2312-3C>A, V779M, and N804K). Three of these mutations (15%) were present in more than 1 proband, being mutation 112insA the most prevalent (frequency approximately 8%) in our sample. The Apo B gene R3500Q mutation was found in only one patient and no underlying defect was found in about 27% of patients. Our data support the notion that Spaniards represent a heterogeneous population with its own spectrum of LDLR gene mutations and that, in our population, FDB has a lower frequency or a milder expression than in central Europe countries.

The tandem affinity purification (TAP) method: a general procedure of protein complex purification

Identification of components present in biological complexes requires their purification to near homogeneity. Methods of purification vary from protein to protein, making it impossible to design a general purification strategy valid for all cases. We have developed the tandem affinity purification (TAP) method as a tool that allows rapid purification under native conditions of complexes, even when expressed at their natural level. Prior knowledge of complex composition or function is not required. The TAP method requires fusion of the TAP tag, either N- or C-terminally, to the target protein of interest. Starting from a relatively small number of cells, active macromolecular complexes can be isolated and used for multiple applications. Variations of the method to specifically purify complexes containing two given components or to subtract undesired complexes can easily be implemented. The TAP method was initially developed in yeast but can be successfully adapted to various organisms. Its simplicity, high yield, and wide applicability make the TAP method a very useful procedure for protein purification and proteome exploration.

Large rearrangements of the LDL receptor gene and lipid profile in a FH Spanish population

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the low-density lipoprotein receptor (LDLR) gene. To date, there has not been a systematic survey of the frequency of gross mutations in the LDLR gene in the Spanish population. The objective of our study was to investigate large rearrangements in the Spanish FH population and the relation between the kind of large rearrangement and the phenotype in carrier families.

MATERIALS AND METHODS

The LDLR gene was screened to detect major rearrangements in a sample of 89 probands. Southern blot, long polymerase chain reaction (PCR), reverse transcription (RT) -PCR and DNA sequencing were used to detect and characterize the mutations.

RESULTS

Five large rearrangements were found in six probands. Two mutations were due to duplications of internal regions of the gene, whereas the rest were caused by partial deletions, which eliminated the promoter region in two cases. The internal rearrangements, two duplications and one deletion, were apparently caused by recombination between ALU sequences and the study of their mRNA indicated that the reading frame was maintained. The analysis of the lipid profile between patients with similar characteristics (age, sex, body mass index, etc.) but carrying mutations that either eliminated the promoter region or produced internal rearrangements showed significant differences (total cholesterol: 366.6 +/- 81.8 vs. 304.6 +/- 25.1 P = 0.023, and LDL cholesterol: 317.7 +/- 65.1 vs. 249.2 +/- 27.4 P = 0.003).

CONCLUSIONS

The frequency of large mutations in a Spanish FH sample was close to 7% and at least four of the mutations found had not been described in other populations. Mutations that eliminate the promoter region originate more severe hypercholesterolemia than defective mutations, which suggests that the absence of the promoter region and transcription of the LDLR gene is worse compensated than the synthesis of a defective LDL receptor.

The apoptosis-promoting factor TIA-1 is a regulator of alternative pre-mRNA splicing

We report here that the apoptosis-promoting protein TIA-1 regulates alternative pre-mRNA splicing of the Drosophila melanogaster gene male-specific-lethal 2 and of the human apoptotic gene Fas. TIA-1 associates selectively with pre-mRNAs that contain 5' splice sites followed by U-rich sequences. TIA-1 binding to the U-rich stretches facilitates 5' splice site recognition by U1 snRNP. This activity is critical for activation of the weak 5' splice site of msl-2 and for modulating the choice of splice site partner in Fas. Structural and functional similarities with the Saccharomyces cerevisiae splicing factor Nam8 suggest striking evolutionary conservation of a mechanism of pre-mRNA splicing regulation that controls biological processes as diverse as meiosis in yeast, dosage compensation in fruit flies, or programmed cell death in humans.

Isolated thrombosis of the external jugular vein

Thrombosis of the external jugular vein (EJV) is an infrequent clinical condition that has been associated with central venous catheterization, head and neck infections, intravenous drug abuse, and compression at the affected site. The authors report a case of thrombotic obstruction of the EJV in the late postoperative period after laparoscopic anterior lumbar interbody fusion. A 40-year-old morbidly obese woman with a depressive syndrome was diagnosed with L5-S1 discopathy and was submitted to laparoscopic anterior isthmic fusion. The operation lasted approximately 6 hours, during which the patient remained in a supine decubitus and Trendelenburg position. The left radial artery, peripheral veins, and right internal jugular vein were canalized. The internal jugular vein catheter was electively withdrawn 24 hours after the intervention. The postoperative period was satisfactory, and the patient was started on prophylaxis with low-molecular-weight heparin. She sat up and began walking at 24 hours and was discharged to her home 4 days after the procedure. Eight days after discharge she returned, experiencing right cervical pain. Palpation revealed a painful induration and erythematous area under the anterior edge of the sternocleidomastoid muscle. Results of otoscopy and laryngoscopy were normal. Cervical echo-Doppler disclosed an image consistent with EJV thrombosis. The most frequent causes of jugular vein thrombosis are mentioned above. A higher incidence has been described after upper abdomen and pelvic surgery; other contributing factors are age, obesity, and associated illness. There are few references in the literature to position-induced EJV thrombosis in the late postoperative period. The authors' patient presented signs and symptoms of EJV thrombosis (probably because of various factors), which was confirmed by echo-Doppler study and treated with 10 days of calcic heparin.

Interaction of the U1 snRNP with nonconserved intronic sequences affects 5' splice site selection

Intron definition and splice site selection occur at an early stage during assembly of the spliceosome, the complex mediating pre-mRNA splicing. Association of U1 snRNP with the pre-mRNA is required for these early steps. We report here that the yeast U1 snRNP-specific protein Nam8p is a component of the commitment complexes, the first stable complexes assembled on pre-mRNA. In vitro and in vivo, Nam8p becomes indispensable for efficient 5' splice site recognition when this process is impaired as a result of the presence of noncanonical 5' splice sites or the absence of a cap structure. Nam8p stabilizes commitment complexes in the latter conditions. Consistent with this, Nam8p interacts with the pre-mRNA downstream of the 5' splice site, in a region of nonconserved sequence. Substitutions in this region affect splicing efficiency and alternative splice site choice in a Nam8p-dependent manner. Therefore, Nam8p is involved in a novel mechanism by which a snRNP component can affect splice site choice and regulate intron removal through its interaction with a nonconserved sequence. This supports a model where early 5' splice recognition results from a network of interactions established by the splicing machinery with various regions of the pre-mRNA.

Plasma Lp(a) values in familial hypercholesterolemia and its relation to coronary heart disease

BACKGROUND AND AIM

To analyze plasma Lp(a) levels and examine different risk factors and coronary heart disease (CHD) in a sample of genetically diagnosed familial hypercholesterolemia (FH) patients.

METHODS AND RESULTS

Ninety heterozygous FH patients and 41 non-FH relatives were enrolled in a study to evaluate their plasma and lipoprotein cholesterol, as well as their triglyceride and Lp(a) levels. We found no differences in plasma Lp(a) levels and log transformed values between 90 FH subjects and their 41 unaffected relatives (22.3 mg/dl +/- 19.4 vs 17.7 mg/dl +/- 21.3 and 1.12 +/- 0.5 vs 0.96 +/- 0.54) nor between null allele and defective allele FH subjects (log Lp (a) levels 2.013 +/- 0.282 vs 1.959 +/- 0.151). FH CHD+ were significantly older, and had higher mean systolic and diastolic blood pressure and higher mean plasma triglyceride levels than FH CHD-. No differences in mean and log transformed Lp(a) plasma concentrations were found.

CONCLUSIONS

Plasma Lp(a) levels are not related to LDL receptor status and class mutations, nor to the presence of CHD in FH patients.

New constructs and strategies for efficient PCR-based gene manipulations in yeast

Gene disruption and tagging can be achieved by homologous recombination in the yeast genome. Several PCR-based methods have been described towards this end. However these strategies are often limited in their applications and/or their efficiencies and may be technically demanding. Here we describe two plasmids for C-terminal tagging of proteins with the IgG binding domain of the Staphylococcus aureus protein A. We also present simple and reliable strategies based on PCR to promote efficient integration of exogenous DNA into the yeast genome. These simple methods are not limited to specific strains or markers and can be used for any application requiring homologous recombination such as gene disruption and epitope tagging. These strategies can be used for consecutive introduction of various constructs into a single yeast strain.

A comprehensive biochemical and genetic analysis of the yeast U1 snRNP reveals five novel proteins

The U1 snRNP is essential for recognition of the pre-mRNA 5'-splice site and the subsequent assembly of the spliceosome. Yeast U1 snRNP is considerably more complex than its metazoan counterpart, which suggests possible differences between yeast and metazoa in early splicing events. We have comprehensively analyzed the composition of yeast U1 snRNPs using a combination of biochemical, mass spectrometric, and genetic methods. We demonstrate the specific association of four novel U1 snRNP proteins, Snu71p, Snu65p, Nam8p, and Snu56p, that have no known metazoan homologues. A fifth protein, Npl3p, is an abundant cellular component that reproducibly co-purifies with the U1 snRNP, but its association is salt-sensitive. Therefore, we are unable to establish conclusively whether it binds specifically to the U1 snRNP. Interestingly, Nam8p and Npl3p were previously assigned functions in (pre-m)RNA-metabolism; however, so far, no association with U1 snRNP has been demonstrated or proposed. We also show that the yeast SmB protein is a U1 snRNP component. Yeast U1 snRNP therefore contains 16 different proteins, including seven snRNP core proteins, three homologues of the metazoan U1 snRNP-specific proteins, and six yeast-specific U1 snRNP proteins. We have simultaneously continued the characterization of additional mutants isolated in a synthetic lethal (MUD) screen for genes that functionally cooperate with U1 snRNA. Consistent with the biochemical results, mud10, mud15, and mud16 are alleles of SNU56, NAM8, and SNU65, respectively. mud10 and mud15 affect the in vivo splicing efficiency of noncanonical introns. Moreover, mud10p strongly affects the in vitro formation of splicing complexes, and extracts from the mud15 strain contain a U1 snRNP that migrates aberrantly on native gels. Finally, we show that Nam8p/Mud15p contributes to the stability of U1 snRNP.

[Familial hypercholesterolemia: molecular identification and characterization of the first compound homozygote in Spain]

Homozygous familial hypercholestrolemia (FH) is a rare genetic disorder (one in 1 million persons) due to two different mutations in the LDL receptor gene (compound homozygous) or, rarely, to the presence of the same mutation in the two aleles. In these patients the absence of a functional LDL receptor produces extreme elevations of plasma cholesterol levels that need an aggressive and expensive treatment with LDL apheresis or hepatic transplantation. The clinical evolution is poor with early coronary heart disease. Molecular biology techniques allow a genetic diagnosis and a genetic counseling in the affected subjects. We have identified and characterized the first compound homozygous of FH in Spain using the single strand conformational polymorphism (SSCP) analysis. The patient is a 30 years old female, who carried two different mutations in the LDL receptor gene: the G528V and the D280G (a new mutation). These mutations produce significant changes in the aminoacid sequence and could be classified as class 2.

A three-allelic polymorphic system in exon 12 of the LDL receptor gene is highly informative for segregation analysis of familial hypercholesterolemia in the Spanish population

We have screened exon 12 of the low density lipoprotein (LDL) receptor gene from 46 familial hypercholesterolemia (FH) heterozygotes and 64 normolipidemic controls for two polymorphisms, HincII, which is caused by a T to C substitution at base 1773, and a C to T transition at base 1725, by using single strand conformation polymorphism (SSCP) analysis. Our results indicate that polymorphism at base 1725, previously reported as very rare from a Japanese sample, is quite frequent in the Spanish population and that it is closely linked to the presence of the HincII site (HincII+). Thus, both polymorphisms constitute a system of three alleles, typed HincII- C1725, HincII+ C1725, and HincII+ T1725, whose frequencies in the FH sample were 0.489, 0.347, and 0.164, respectively. No significant differences were found in the allele frequencies between the FH and control samples. This three-allelic polymorphic system provides a higher information content (PIC value) than the HincII RFLP alone (0.537 versus 0.373, respectively); therefore, it is an extremely useful marker for linkage analysis of FH in Caucasian populations.

Seven DNA polymorphisms in the LDL receptor gene: application to the study of familial hypercholesterolemia in Spain

We have performed restriction fragment length polymorphism (RFLP) analysis at the low density lipoprotein receptor (LDLR) locus in order to investigate the molecular genetics of familial hypercholesterolemia (FH) in Spain. Firstly, a sample of 50 unrelated patients with a clinical diagnosis of FH was screened for the presence of major rearrangements at this locus by Southern blot analysis of BglII digested genomic DNA. Four different mutations were detected, accounting for 8% of the mutant alleles in the Spanish FH sample. Then, we determined the relative allele frequency and estimated linkage disequilibrium between seven RFLPs of the LDLR gene in the remaining 46 FH patients and in 61 normolipidemic controls. HincII, AvaII, PvuII, MspI, and NcoI are the most polymorphic sites with individual PIC values higher than 0.28, whereas the TaqI and StuI sites display low levels of polymorphism. The usefulness of the seven RFLPs to confirm a clinical diagnosis of FH was investigated in 15 FH-families, consisting of 118 individuals, in whom the presence of Familial Defective Apolipoprotein B-100 (FDB) due to the apoB3500 mutation was excluded. Independent haplotypes were constructed for 71 chromosomes: 15 FH and 56 control haplotypes. A total of 14 different haplotypes was found. In 12 families, clinical diagnosis of FH was confirmed by cosegregation analysis, which makes these RFLPs useful for studying the inheritance of the LDLR gene in 80% of Spanish families with FH. Comparison of haplotypes found in the Spanish sample with those found in Swiss and Norwegians suggests heterogeneity of haplotypes among European populations.