Neuroanatomical changes in a mouse model of early life neglect

Using a novel mouse model of early life neglect and abuse (ENA) based on maternal separation with early weaning, George et al. (BMC Neurosci 11:123, 2010) demonstrated behavioral abnormalities in adult mice, and Bordner et al. (Front Psychiatry 2(18):1-18, 2011) described concomitant changes in mRNA and protein expression. Using the same model, here we report neuroanatomical changes that include smaller brain size and abnormal inter-hemispheric asymmetry, decreases in cortical thickness, abnormalities in subcortical structures, and white matter disorganization and atrophy most severely affecting the left hemisphere. Because of the similarities between the neuroanatomical changes observed in our mouse model and those described in human survivors of ENA, this novel animal model is potentially useful for studies of human ENA too costly or cumbersome to be carried out in primates. Moreover, our current knowledge of the mouse genome makes this model particularly suited for targeted anatomical, molecular, and pharmacological experimentation not yet possible in other species.

Association of polymorphisms in HCN4 with mood disorders and obsessive compulsive disorder

Hyperpolarization activated cyclic nucleotide-gated (HCN) potassium channels are implicated in the control of neuronal excitability and are expressed widely in the brain. HCN4 is expressed in brain regions relevant to mood and anxiety disorders including specific thalamic nuclei, the basolateral amygdala, and the midbrain dopamine system. We therefore examined the association of HCN4 with a group of mood and anxiety disorders. We genotyped nine tag SNPs in the HCN4 gene using Sequenom iPLEX Gold technology in 285 Caucasian patients with DSM-IV mood disorders and/or obsessive compulsive disorder and 384 Caucasian controls. HCN4 polymorphisms were analyzed using single marker and haplotype-based association methods. Three SNPs showed nominal association in our population (rs12905211, rs3859014, rs498005). SNP rs12905211 maintained significance after Bonferroni correction, with allele T and haplotype CTC overrepresented in cases. These findings suggest HCN4 as a genetic susceptibility factor for mood and anxiety disorders; however, these results will require replication using a larger sample.

Parallel declines in cognition, motivation, and locomotion in aging mice: association with immune gene upregulation in the medial prefrontal cortex

Aging in humans is associated with parallel changes in cognition, motivation, and motoric performance. Based on the human aging literature, we hypothesized that this constellation of age-related changes is mediated by the medial prefrontal cortex and that it would be observed in aging mice. Toward this end, we performed detailed assessments of cognition, motivation, and motoric behavior in aging mice. We assessed behavioral and cognitive performance in C57Bl/6 mice aged 6, 18, and 24 months, and followed this with microarray analysis of tissue from the medial prefrontal cortex and analysis of serum cytokine levels. Multivariate modeling of these data suggested that the age-related changes in cognition, motivation, motor performance, and prefrontal immune gene expression were highly correlated. Peripheral cytokine levels were also correlated with these variables, but less strongly than measures of prefrontal immune gene upregulation. To determine whether the observed immune gene expression changes were due to prefrontal microglial cells, we isolated CD11b-positive cells from the prefrontal cortex and subject them to next-generation RNA sequencing. Many of the immune changes present in whole medial prefrontal cortex were enriched in this cell population. These data suggest that, as in humans, cognition, motivation, and motoric performance in the mouse change together with age and are strongly associated with CNS immune gene upregulation.

Functional genomic and proteomic analysis reveals disruption of myelin-related genes and translation in a mouse model of early life neglect

Early life neglect is an important public health problem which can lead to lasting psychological dysfunction. Good animal models are necessary to understand the mechanisms responsible for the behavioral and anatomical pathology that results. We recently described a novel model of early life neglect, maternal separation with early weaning (MSEW), that produces behavioral changes in the mouse that persist into adulthood. To begin to understand the mechanism by which MSEW leads to these changes we applied cDNA microarray, next-generation RNA-sequencing (RNA-seq), label-free proteomics, multiple reaction monitoring (MRM) proteomics, and methylation analysis to tissue samples obtained from medial prefrontal cortex to determine the molecular changes induced by MSEW that persist into adulthood. The results show that MSEW leads to dysregulation of markers of mature oligodendrocytes and genes involved in protein translation and other categories, an apparent downward biasing of translation, and methylation changes in the promoter regions of selected dysregulated genes. These findings are likely to prove useful in understanding the mechanism by which early life neglect affects brain structure, cognition, and behavior.

Maternal separation with early weaning: a novel mouse model of early life neglect

Background

Childhood adversity is associated with increased risk for mood, anxiety, impulse control, and substance disorders. Although genetic and environmental factors contribute to the development of such disorders, the neurobiological mechanisms involved are poorly understood. A reliable mouse model of early life adversity leading to lasting behavioral changes would facilitate progress in elucidating the molecular mechanisms underlying these adverse effects. Maternal separation is a commonly used model of early life neglect, but has led to inconsistent results in the mouse.

Results

In an effort to develop a mouse model of early life neglect with long-lasting behavioral effects in C57BL/6 mice, we designed a new maternal separation paradigm that we call Maternal Separation with Early Weaning (MSEW). We tested the effects of MSEW on C57BL/6 mice as well as the genetically distinct DBA/2 strain and found significant MSEW effects on several behavioral tasks (i.e., the open field, elevated plus maze, and forced swim test) when assessed more than two months following the MSEW procedure. Our findings are consistent with MSEW causing effects within multiple behavioral domains in both strains, and suggest increased anxiety, hyperactivity, and behavioral despair in the MSEW offspring. Analysis of pup weights and metabolic parameters showed no evidence for malnutrition in the MSEW pups. Additionally, strain differences in many of the behavioral tests suggest a role for genetic factors in the response to early life neglect.

Conclusions

These results suggest that MSEW may serve as a useful model to examine the complex behavioral abnormalities often apparent in individuals with histories of early life neglect, and may lead to greater understanding of these later life outcomes and offer insight into novel therapeutic strategies.

Multiple myeloma: recognition and management

Multiple myeloma is the malignant proliferation of plasma cells involving more than 10 percent of the bone marrow. The multiple myeloma cell produces monoclonal immunoglobulins that may be identified on serum or urine protein electrophoresis. Bone pain related to multiple lytic lesions is the most common clinical presentation. However, up to 30 percent of patients are diagnosed incidentally while being evaluated for unrelated problems, and one third of patients are diagnosed after a pathologic fracture, commonly of the axial skeleton. Multiple myeloma must be differentiated from other causes of monoclonal gammopathy, including monoclonal gammopathy of undetermined significance, heavy chain disease, plasmacytoma and Waldenstrom macroglobulinemia. Chemotherapy with melphalan-prednisone is the standard treatment for multiple myeloma. Other treatment modalities include polychemotherapy and bone marrow transplantation. Only 50 to 60 percent of patients respond to therapy. The aggregate median survival for all stages of multiple myeloma is three years.

Military penetrating craniocerebral injuries. Applications to civilian triage and management

Although facilities at many civilian centers far exceed those historically available to military neurosurgeons in the field, the principles derived from combat injuries continue to apply. It is hoped that there may be differences in salvageability at the margin owing to the availability of more sophisticated imaging and critical care monitoring techniques, neuroanesthesia, and the advent of possible pharmacologic neural salvage agents.

Acute subdural hematoma after aneurysmal rupture; evacuation with aneurysmal clipping after emergent infusion computed tomography: case report

A 74-year-old woman sought treatment after an initial subarachnoid hemorrhage verified on computed tomographic scan with no focal neurological deficit. Shortly after admission, she sustained a second subarachnoid hemorrhage with acute neurological decompensation. A repeat computed tomographic scan revealed increased blood along the right medial temporal region, as well as in the interhemispheric fissure and bilateral sylvian cisterns. Also evident was a right hemispheric acute subdural hematoma. The patient's rapidly deteriorating neurological status precluded a cerebral angiogram; therefore, a double-dose infusion computed tomographic scan was performed. This revealed a cerebral artery aneurysm adjacent to the right medial temporal hematoma. She was taken to the operating room on the basis of this study. After evacuation of the right hemispheric subdural hematoma and clipping of the right posterior communicating artery aneurysm, the patient made a rapid, full neurological recovery.

Subarachnoid hemorrhage due to intracranial aneurysm: current management

Intracranial aneurysms cause in excess of 28,000 subarachnoid hemorrhages per year in North America. The combined mortality and morbidity from aneurysmal subarachnoid hemorrhage exceeds 40%, and therefore yields a remarkably high toll of human and economic loss. As a lesion that is treatable, even curable at particular stages, management decisions are critical. In spite of significant advances in surgical technique, the mortality rate remains high. Erroneous diagnosis in good-grade patients significantly contributes to the lack of improvement in current statistics. Diagnosis and subsequent contemporary management is discussed.

The natural history of symptomatic arteriovenous malformations of the brain: a 24-year follow-up assessment

The authors have updated a series of 166 prospectively followed unoperated symptomatic patients with arteriovenous malformations (AVM's) of the brain. Follow-up data were obtained for 160 (96%) of the original population, with a mean follow-up period of 23.7 years. The rate of major rebleeding was 4.0% per year, and the mortality rate was 1.0% per year. At follow-up review, 23% of the series were dead from AVM hemorrhage. The combined rate of major morbidity and mortality was 2.7% per year. These annual rates remained essentially constant over the entire period of the study. There was no difference in the incidence of rebleeding or death regardless of presentation with or without evidence of hemorrhage. The mean interval between initial presentation and subsequent hemorrhage was 7.7 years.

Heterogeneity of cerebral cavernous hemangiomas diagnosed by MR imaging

The cavernous hemangioma (cavernoma) is increasingly recognized as a vascular malformation of the brain that may present with seizures, hemorrhage, or progressive neurological deficit. Since 1985 we have identified 13 cases of presumed cavernoma of the brain based on the findings on CT, selective angiography, and magnetic resonance (MR) imaging. In each case CT showed a high density lesion that was "occult" or "cryptic" on angiography. However, within all lesions MR revealed a complex internal structure consisting of reticulated patches of high and low intensity signal surrounded by a hypointense rim on T1- and T2-weighted pulse sequences. Of the nine operated cases, five resected specimens were compatible with pure arteriovenous malformations (AVMs), and the other four were mixtures of cavernoma with either AVM or venous angioma. Our experience strongly suggests that the above complex of radiographic findings is not at all specific for the cavernoma. We propose that the major common factor shared by such "cavernomatoid" malformations is low blood flow. We believe low flow lesions follow a relatively benign clinical course, and they readily lend themselves to surgical resection.

Penetrating craniocerebral injuries in the Israeli involvement in the Lebanese conflict, 1982-1985. Analysis of a less aggressive surgical approach

From June, 1982, through June, 1985, 113 patients were evacuated to Rambam Maimonides Medical Center with penetrating craniocerebral injuries sustained in ongoing military hostilities in Lebanon. Two factors distinguished this group of patients from those presenting in earlier conflicts: 1) this was the first large series in which computerized tomography (CT) was routinely used to initially evaluate combat head injuries; and 2) in an effort to preserve maximum cerebral tissue, intracranial debridement was significantly less vigorous than that advocated during the Korean or Vietnam conflicts. No efforts were made to locate or remove in-driven bone or metal fragments visualized on CT unless they readily presented themselves on gentle irrigation. In fact, it was elected to treat a number of patients without intracranial hematomas nonoperatively. The acute outcome was quite similar to that reported in Vietnam series in respect to both complications and mortality. Of the 83 survivors, 46 were Israeli citizens and thus were available for follow-up review. These 46 patients were reevaluated in late 1988, a mean follow-up period of 5.9 years. None had died in the interim; 10 had developed chronic seizure disorders, and there was one case of delayed meningitis in a patient with no retained fragments. Repeat CT scans were performed on 43 patients; 22 (51%) were found to have retained intracranial bone fragments. No relationship existed between the presence of retained fragments and the development of either a seizure disorder or an infection of the central nervous system. These findings suggest that not only is it unnecessary to reoperate for retained bone fragments, but it may also be possible to temper the initial debridement in an effort to preserve additional cerebral tissue.

Surgical excision of a cavernous hemangioma of the rostral brain stem: case report

A 23-year-old pregnant woman presented with sudden diplopia, ataxia, hemiparesis, and headache secondary to a brain stem hemorrhage. Magnetic resonance imaging (MRI) revealed a hematoma associated with a probable cavernous hemangioma of the rostral brain stem. In this report, we discuss the MRI findings leading to the preoperative diagnosis, as well as the surgical techniques involved in the successful resection.

Treatment of a central arteriovenous malformation of the mandible with cyanoacrylate: a 4-year follow-up

Large arteriovenous malformations of the jaws are relatively rare, potentially life-threatening lesions. When the lesion is not suspected, extraction of teeth can be fatal. The occurrence and treatment of arteriovenous vascular communications in the head and neck region have traditionally presented most perplexing problems. Traditional treatment has usually involved the obtaining of proximal and distal vascular control and surgical removal of the lesions, when feasible. This article presents a case that is of particular interest because it illustrates the successful use of cyanoacrylate as the only treatment for a large arteriovenous malformation of the left side of the mandible. A 4-year follow-up shows no evidence of the lesion and demonstrates complete regeneration of bone in the same area.

Morphological studies of human arteriovenous malformations. Effects of isobutyl 2-cyanoacrylate embolization

Ten patients with symptomatic arteriovenous malformations (AVM's) underwent embolization with isobutyl 2-cyanoacrylate (Bucrylate) delivered via a mini-balloon catheter according to the protocol of George and Pevsner. These patients underwent surgical removal of their embolized AVM, and surgical specimens were evaluated by light and scanning electron microscopy. Ten other patients with AVM's underwent surgical resection without prior embolization, and these surgical specimens were evaluated in a similar manner. Results from this study indicate that Bucrylate incites an inflammatory response characterized by foreign-body giant cells. This reaction was present as early as 3 weeks after embolization and persisted in specimens resected almost 1 year after the last embolization. No such reaction was observed in unembolized AVM's. Both light and scanning electron microscopy demonstrated a lattice structure of the Bucrylate embolus within the AVM vessels. These studies also demonstrated micro-channels within the Bucrylate embolus and the presence of what appears to be normal red blood cells within the latticework of the embolus. Vascular endothelium not in direct contact with the Bucrylate embolus retains a normal morphology as revealed by scanning electron microscopy.

Interventional radiology polymer update: acrylic

An overview of intravascular interventional embolic materials is presented. The physicochemical and biological properties of the monomer isobutyl 2-cyanoacrylate are discussed with specific details regarding therapeutic applications.