Nucleus accumbens functional connectivity discriminates medication-overuse headache

Medication-overuse headache (MOH) is a secondary form of headache related to the overuse of triptans, analgesics and other acute headache medications. It is believed that MOH and substance addiction share some similar pathophysiological mechanisms. In this study we examined the whole brain resting state functional connectivity of the dorsal and ventral striatum in 30 patients (15 MOH and 15 non-MOH patients) to investigate if classification algorithms can successfully discriminate between MOH and non-MOH patients on the basis of the spatial pattern of resting state functional connectivity of the dorsal and ventral striatal region of interest. Our results indicated that both nucleus accumbens and dorsal rostral putamen functional connectivity could discriminate between MOH and non-MOH patients, thereby providing possible support to two interpretations. First, that MOH patients show altered reward functionality in line with drug abusers (alterations in functional connectivity of the nucleus accumbens). Second, that MOH patients show inability to break habitual behavior (alterations in functional connectivity of the dorsal striatum). In conclusion, our data showed that MOH patients were characterized by an altered functional connectivity of motivational circuits at rest. These differences could permit the blind discrimination between the two conditions using classification algorithms. Considered overall, our findings might contribute to the development of novel diagnostic measures.

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Nucleus accumbens functional connectivity could discriminate between MOH and non-MOH patients.

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Dorsal rostral putamen functional connectivity could also discriminate between MOH and non-MOH patients.

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Our data provide insights on possible pathophysiological mechanisms of medication abuse.

Pharmacological Profile of Nociceptin/Orphanin FQ Receptors Interacting with G-Proteins and β-Arrestins 2

Nociceptin/orphanin FQ (N/OFQ) controls several biological functions by selectively activating an opioid like receptor named N/OFQ peptide receptor (NOP). Biased agonism is emerging as an important and therapeutically relevant pharmacological concept in the field of G protein coupled receptors including opioids. To evaluate the relevance of this phenomenon in the NOP receptor, we used a bioluminescence resonance energy transfer technology to measure the interactions of the NOP receptor with either G proteins or β-arrestin 2 in the absence and in presence of increasing concentration of ligands. A large panel of receptor ligands was investigated by comparing their ability to promote or block NOP/G protein and NOP/arrestin interactions. In this study we report a systematic analysis of the functional selectivity of NOP receptor ligands. NOP/G protein interactions (investigated in cell membranes) allowed a precise estimation of both ligand potency and efficacy yielding data highly consistent with the known pharmacological profile of this receptor. The same panel of ligands displayed marked differences in the ability to promote NOP/β-arrestin 2 interactions (evaluated in whole cells). In particular, full agonists displayed a general lower potency and for some ligands an inverted rank order of potency was noted. Most partial agonists behaved as pure competitive antagonists of receptor/arrestin interaction. Antagonists displayed similar values of potency for NOP/Gβ₁ or NOP/β-arrestin 2 interaction. Using N/OFQ as reference ligand we computed the bias factors of NOP ligands and a number of agonists with greater efficacy at G protein coupling were identified.

Unawareness of bipolar disorder: the role of the cingulate cortex

Reduced awareness of illness is a well-known phenomenon that has been understudied in remitted patients with bipolar disorder. In particular, the relationship between reduced awareness and executive dysfunction is an intriguing question that has yet to be resolved. The aim of the current study is to analyze the link between reduced awareness, brain dysfunction, and concomitant cognitive-behavioral disturbances from a neurocognitive perspective. In previous studies, we demonstrated the role of the anterior cingulate cortex (ACC) in the unawareness of distinct pathologies that exhibit overlapping symptoms in the context of overlapping circuit-specific dysfunction. Given the clinical importance of the results obtained, the present study considers six aware and four unaware remitted bipolar disorder patients. Cingulate functionality was assessed with functional magnetic resonance imaging while patients performed a go/no-go task. Patients were also studied on an overall cognitive task battery and with behavioral assessment of mood changes in terms of apathy and disinhibited behavior. Unaware patients showed frontoparietal hypo-perfusion, with a significant reduction of task-sensitive activity in the bilateral superior and middle frontal gyrus, putamen, insular, and ACCs.

[The molecular mechanism of evolution of changes in the genetic code]

Alterations to the standard genetic code have been found in both prokaryotes and eukaryotes. This finding demolished the central dogma of molecular biology, postulated by Crick in 1968, of an immutable and universal genetic code and raised the question of how organisms survive genetic code alterations? Recent studies suggest that genetic code alterations are driven by selection using a mechanism that requires translational ambiguity. In C. albicans, the leucine CUG codon is decoded as serine through structural alterations of the translational machinery, in particular, of a Ser-tRNACAG which has dual identity and novel decoding properties. Here, we review the molecular mechanism of CUG reassignment focusing on the structural change of the translational machinery and on the impact that such alteration had on the evolution of the Candida albicans genome.

Fetal magnetic resonance imaging in the prenatal diagnosis of cerebellar hemorrhage

We report the case of a fetus with a sonographic mid-gestation diagnosis of hyperechogenic cerebellum suspected to be of hemorrhagic origin on fetal brain magnetic resonance imaging (MRI). No etiological factors for fetal hemorrhage were found other than a maternal heterozygocity for factor V Leiden. Following termination of the pregnancy, autopsy confirmed the prenatal diagnosis of massive cerebellar hemorrhage without underlying vascular anomaly. As an additional tool to ultrasonography, fetal brain MRI can affirm the hemorrhagic origin of hyperechogenic cerebellar lesions, especially by showing a high signal on T1-weighted images.

A clinical and molecular study of 26 females with Xp deletions with special emphasis on inherited deletions

We have undertaken a clinical study of 26 females with deletions of Xp including five mother-daughter pairs. Cytogenetic and molecular analyses have mapped the breakpoints of the deletions. We determined the parental origin of each abnormality and studied the X-inactivation patterns. We describe the clinical features and compare them with the amount of Xp material lost. We discuss the putative loci for features of Turner syndrome and describe how our series contributes further to their delineation. We conclude that (1) fertility can be retained even with the loss of two-thirds of Xp, thus, if there are genes on Xp for ovarian development, they must be at Xp11-Xp11.2; (2) in our sample of patients there is no evidence to support the existence of a single lymphogenic gene on Xp; (3) there is no evidence for a second stature locus in proximal Xp; (4) there is no evidence to support the existence of a single gene for naevi; (5) we suggest that the interval in Xp21.1-Xp11.4 between DXS997 and DXS1368 may contain a gene conferring a predisposition to hypothyroidism.

Comparison of Magnetic Resonance Angiography (MRA) and Duplex Ultrasound Arterial Mapping (DUAM) prior to infrainguinal arterial reconstruction

OBJECTIVE

the purpose of this study is to compare Magnetic Resonance Angiography (MRA) to Duplex Ultrasound Arterial Mapping (DUAM) and intraoperative findings to determine the clinical, accuracy of MRA for planning lower extremity revascularization procedures.

METHODS

forty-two patients who underwent lower extremity revascularization procedures had both MRA and DUAM evaluations. These data were analyzed retrospectively and two distinct endpoints were considered. First, we compared the MRA and DUAM findings for aorto-iliac, femoral-popliteal and infra-popliteal segments to intraoperative findings and evaluated the degree to which they agreed. Second, if there was a disagreement between imaging modalities, it was established whether a change in operative procedure would have resulted.

RESULTS

MRA and DUAM findings agreed in 26 of 31 cases (83%) of aorto-iliac segments, in 25 of 31 cases (81%) of femoral-popliteal segments, and in 16 of 21 cases (76%) of infra-popliteal segments. In total, DUAM agreed with intraoperative findings in 98% of cases while MRA agreed in 82% (p<.001). Disagreement between intraoperative findings and DUAM lead to an alternate surgical procedure in only one case (2%) while disagreement with MRA lead to a different procedure in 38% of cases (p<.001).

CONCLUSIONS

these data show that MRA is not yet adequate to replace conventional angiography and is less accurate that DUAM. Further improvements are necessary before MRA can be used as the sole modality for formulation of a pre-operative plan for lower extremity revascularization.

Lower extremity revascularization without preoperative contrast arteriography: experience with duplex ultrasound arterial mapping in 485 cases

This study reviews our experience with duplex ultrasound arterial mapping (DUAM) for preoperative evaluation in 466 patients (262 men) who underwent 485 lower extremity revascularization procedures from January 1, 1998 to May 30, 2001. Preoperative imaging consisted of DUAM alone in 449 procedures and DUAM and contrast angiography (CA) in 36. An attempt to image from the distal aorta to the pedal arteries was made in all the patients. The selection of optimal inflow and outflow bypasses anastomotic sites was based on a schematic drawing following DUAM examination. Inflow disease was also assessed by intraoperative pressure gradient (IPG) between the distal anastomosis and radial arteries, and completion arteriography of the runoff vessels was obtained, which was correlated with the preoperative findings. Indications for surgery were severe claudication in 91 (19%) limbs, tissue loss in 197 (40%), rest pain in 113 (23%), acute ischemia in 46 (10%), popliteal aneurysm in 18 (4%), superficial femoral artery aneurysm in 1, abdominal aortic aneurysm with claudication in 1, and failing graft in 18 (4%). Age ranged from 30 to 97 years (mean 72 +/- 12 (SD) years) and risk factors such as diabetes, hypertension, use of tobacco, coronary artery disease, and end-stage renal disease were present in 45%, 45%, 44%, 44%, and 13% of the patients, respectively. One hundred twenty-one (25%) limbs had at least 1 previous ipsilateral revascularization. The mean DUAM time was 66 +/- 20 (SD) min (30-150 min). Additional preoperative imaging was deemed necessary in 36 cases due to extensive ulcers, edema, severe arterial wall calcification, and very poor runoff. The distal anastomosis was to the popliteal artery in 173 cases and to the tibial and pedal arteries in 255. Inflow procedures to the femoral arteries, embolectomy, thrombectomy, balloon angioplasty, and patch angioplasty accounted for the remaining 57 cases. Overall, 6-, 12-, and -24- month secondary patency rates were 86%, 80%, and 66%, respectively. This early experience shows that high-quality arterial ultrasonography performed by a highly skilled vascular technologist may represent an alternative to conventional arteriography for patients in need of lower extremity revascularization. Because of limitations inherent to the technique and very poor runoff observed on ultrasonographic examination, additional preoperative imaging procedure's are needed for certain patients.

A 1.5 million-base pair inversion polymorphism in families with Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is most often caused by hemizygous deletion of a 1.5-Mb interval encompassing at least 17 genes at 7q11.23 (refs. 1,2). As with many other haploinsufficiency diseases, the mechanism underlying the WBS deletion is thought to be unequal meiotic recombination, probably mediated by the highly homologous DNA that flanks the commonly deleted region. Here, we report the use of interphase fluorescence in situ hybridization (FISH) and pulsed-field gel electrophoresis (PFGE) to identify a genomic polymorphism in families with WBS, consisting of an inversion of the WBS region. We have observed that the inversion is hemizygous in 3 of 11 (27%) atypical affected individuals who show a subset of the WBS phenotypic spectrum but do not carry the typical WBS microdeletion. Two of these individuals also have a parent who carries the inversion. In addition, in 4 of 12 (33%) families with a proband carrying the WBS deletion, we observed the inversion exclusively in the parent transmitting the disease-related chromosome. These results suggest the presence of a newly identified genomic variant within the population that may be associated with the disease. It may result in predisposition to primarily WBS-causing microdeletions, but may also cause translocations and inversions.

A new syndrome with craniofacial and skeletal dysmorphisms and developmental delay

We report a 16-year-old boy with multiple craniofacial and skeletal dysmorphic features including brachycephaly, acrocephaly, hypertelorism, wide palpebral fissures, broad nose, anteverted nares, broad columella, long and smooth philtrum, thin upper lip, macrostomia, carp-like mouth, micrognathia, low-set and posteriorly angulated ears with small and abnormal pinnae, a low posterior hairline, a short neck, hypoplastic and widely-spaced nipples, multiple severe pterygia, an umbilical hernia, metatarsus varus, low implantation of the halluces, and delayed motor and language development. An MRI of the head showed bilateral frontal pachygyria but no sign of heterotopia. The unique features of our patient suggest that he represents a new syndrome.

Successful prevention of hiv transmission from mother to infant in Brazil using a multidisciplinary team approach

OBJECTIVES

To determine the HIV vertical transmission rate (VTR) and associated risk factors by use of zidovudine and infant care education in Brazil.

METHODS

Since 1995, a prospective cohort of HIV infected pregnant women has been followed at the Federal University of Rio de Janeiro. A multidisciplinary team was established to implement the best available strategy to prevent maternal-infant HIV transmission. Patients with AIDS or low CD(4) and high viral load received anti-retroviral drugs in addition to zidovudine. Children were considered infected if they had 2 positive PCR-RNA tests between 1 and 4 months of age, or were HIV antibody positive after 18 months. Education regarding infant treatment and use of formula instead of breast feeding was provided.

RESULTS

Between 1995 and August, 2000, HIV status was determined for 145 infants. Compliance with intra-partum treatment, infant treatment and use of formula was 88.2%. Intra-partum zidovudine treatment was completed in 134/145 (92.6%) of patients; 88.1% had rupture of membranes < 4 hours; 85.4% of mothers were asymptomatic. The mean CD(4) count was 428.4 cells and mean viral load 39,050 copies. HIV vertical transmission rate was 4/145 (2.75%; CI: 0.1%-5.4%). The only risk factor significantly associated with transmission was a failure to use zidovudine intra-partum in 2 of the 4 mothers (50% versus 6.4% in non-transmitting mothers). A trend toward low CD(4) and high viral load at entry, and rupture of membranes > 4 hours were associated with increased HIV transmission.

CONCLUSION

HIV vertical transmission in Brazil was reduced to a level similar to other countries with the most effective prevention programs using a multidisciplinary team approach. A high level of compliance for use of anti-retroviral drugs, the provision of health education to mothers, and use of formula for all exposed infants.