How many genes in a genome?

Despite the current good level of annotation, the Drosophila genome still holds surprises. A recent study has added perhaps 2,000 genes to the predicted total, and raises a number of questions about how genome annotation data should be stored and presented.     

Thalamic abscess: a stereotactically treatable lesion

A 69-year-old man developed abdominal pain, fever, shaking chills and acute hemiplegia. Computed tomography (CT) scanning demonstrated a hematoma within a thalamic space-occupying lesion having the radiological characteristics of a malignant glioma. Low-grade fever and leukocytosis persisted and follow-up CT scanning showed ring enhancement of the thalamic lesion and ependymitis suggesting a cerebral abscess. Stereotactic aspiration achieved drainage of the abscess and relief of mass effect and provided pus from which a causative organism was identified and treated with appropriate antibiotics. Contrast-enhanced CT scan should be obtained in cases of hemorrhage within mass lesions and tissue diagnosis should be achieved even in deep brain regions, as this can be accomplished safely using stereotactic techniques.     

Selective neuromuscular blockade for intraoperative electrocorticography

Local anesthesia is advocated for cortical mapping in certain neurological procedures. Occasionally, however, a modified general anesthetic is necessary. We describe a technique of balanced anesthesia in which the arm opposite to the craniotomy is selectively isolated from the effect of the neuromuscular blocking agent and hence preserves its motor response to cortical stimulation. The technique secures complete immobility of the patient during mapping of the brain, shortens the stimulation time, facilitates the localization of the motor cortex, precludes the development of full-blown seizures, increases safety and is well tolerated.     

Molecular biology and bacterial secondary transporters

Bacterial permeases form a family of membrane proteins that actively transport nutrients according to a cation-solute cotransport mechanism. The purpose of this review is to consider the many perspectives offered by in vitro recombinant DNA and molecular biology techniques for analysis of structure-function relationships. In the first part of this review, the kinetic parameters that permit characterization of either the partial steps or the overall transport reaction are summarized. We then list the molecular properties (protein sequence and composition, secondary structure, biochemical identification) of the carriers readily available on cloning a structural gene into plasmids. Finally, the usefulness of site-specific, oligonucleotide-directed mutagenesis for investigation of the functional importance of given residues (cysteins and histidines) or domains of the transport proteins is illustrated.     

Pattern of the evolution of HIV-1 enν gene in C?te d?Ivoire

Cête d׳Ivoire continues to have the highest HIV-1 prevalence rate in West Africa, although the infection number is in constant decline. The external envelope protein of the viruses is a likely site of selection, and responsible for receptor binding and entry into host cells, and therefore constitutes an ideal region with which to investigate the evolutionary processes acting on HIV-1. In this study, we analyse 189 envelope glycoprotein V3 loop region sequences of viruse isolates from 1995 to 2009, from HIV-1 untreated patients living in Cête d׳Ivoire, to decipher the temporal relationship between disease diversity, divergence and selection. Our analyses show that the nonsynonymous and synonymous ratio (dN/dS) was lower than 1 for viral populations analysed within 15 years, which showed the sequences did not undergo adequate immune pressure. The phylogenetic tree of the sequences analysed demonstrated distinctly long internal branches and short external branches, suggesting that only a small number of viruses infected the new host cell at each transmission. In addition to identifying sites under purifying selection, we also identified neutral sites that can cause false positive inference of selection. These sites presented form a resource for future studies of selection pressures acting on HIV-1 enν gene in Cête d׳Ivoire and other West African countries.     

Ocular melanoma in a patient successfully treated for diffuse malignant peritoneal mesothelioma: a case report

Myoid hamartomas of the breast are extremely rare breast lesions, with a poorly understood pathogenesis. We describe the case of a 38-year-old premenopausal woman who presenting with a mass in the left breast. Mammography revealed an oval mass that was partly indistinct, and ultrasonography showed a hypoechoic mass with a slightly irregular margin. Bilateral breast dynamic magnetic resonance imaging was performed for a more detailed evaluation. The images showed rapid initial enhancement and a microlobulated margin. Because the suspicion of malignancy was strong at that time, core needle biopsy was performed. Histologically, the tumor was identified as fibroadenoma. A case of myoid hamartoma of the breast that proved difficult to diagnose is reported, and discussed with reference to the literature.