''Gender gap'' in multiple sclerosis: magnetic resonance imaging evidence

The authors evaluated the gender difference in the magnetic resonance imaging characteristics of the lesions occurring in the brain of 413 multiple sclerosis (MS) patients. Men had fewer contrast-enhancing lesions (P = 0.01), but a higher proportion of lesions evolving into 'black holes' (P = 0.001), when compared with women. Thus, our data indicate that men with MS are prone to develop less inflammatory, but more destructive lesions than women. This study results provides support for a modulation of the MS pathological changes by gender.     

Detection of mucus glycoconjugates in human conjunctiva by using the lectin-colloidal gold technique in TEM. III. A quantitative study in asymptomatic contact lens wearers

We characterized the mucus glycoconjugates produced by goblet and non-goblet epithelial cells in asymptomatic contact lens (CL) wearers. We employed four lectins (proteins of vegetal origin which specifically recognize glycosidic residues: WGA, PNA, SBA and ConA) conjugated with colloidal gold as ultrastructural marker, at Transmission Electron Microscopy. A computerized quantitative analysis was carried out in order to compare the results from the CL wearers to those from the control patients. Goblet cells produce different amount of glycosidic residues, in particular, a significant decrease in the distribution of sialic acid, N-acetylglucosamine, N-acetylgalactosamine, galactose-N-acetylgalactosamine and mannose was observed. The content of glycosidic residues in the mucus vesicles of the non-goblet epithelial cells appeared unchanged as to the normal situation. We speculate that the CL could possibly contribute to the failure of the tear film stability by altering the production of mucus.     

Heparin-interacting sites of bovine lactoferrin are involved in anti-adenovirus activity

Lactoferrin, a member of the transferrin family of approximately 80 kDa, consists of a single polypeptide chain folded in two symmetric, globular lobes (N- and C-lobes), each able to bind one ferric ion. This glycoprotein, found in physiological fluids of mammals, plays an important role in immune regulation and in defense mechanisms against bacteria, fungi, parasites, and viruses. Although the antiviral activity of lactoferrin is one of the major biological functions of such protein, the mechanism of action is still under debate. We have investigated both the role of tryptic fragments of bovine lactoferrin and the mechanism of lactoferrin antiviral effect toward adenovirus infection in HEp-2 cells. The results obtained demonstrated that the anti-adenovirus activity of lactoferrin is mediated by the N-terminal half of the protein as the N-lobe was able to inhibit adenovirus infection, even if at lower extent than undigested lactoferrin, whereas C-lobe was ineffective. The results also showed that the anti-adenovirus action of lactoferrin and of its N-terminal peptide lactoferricin took place on virus attachment to cell membrane, mainly through competition for common glycosaminoglycan receptors. The data provide evidence that the anti-adenovirus activity of lactoferrin is mediated mainly by the cluster of positive charges at the N-terminus of whole molecule and that the N-terminal peptide lactoferricin alone is sufficient to prevent infection.     

Invasive pneumococcal infection in a healthy infant caused by two different serotypes

We present a case of invasive pneumococcal infection in a healthy 10-month-old infant from whom Streptococcus pneumoniae serotype 23F was isolated from the blood and serotype 23B was isolated from the cerebrospinal fluid. Both serotypes were penicillin nonsusceptible. Pulsed-field gel electrophoresis analysis demonstrated that the two serotypes had distinct DNA patterns, indicating that infection did not occur as a result of capsular transformation but as a result of a mixed infection with two distinct pneumococcal serotypes.     

Uniparental disomy 7 in Silver--Russell syndrome and primordial growth retardation

Maternal uniparental disomy for the entire chromosome 7 hasso far been reported in three patients with intrauterine andpostnatal growth retardation. Two were detected because theywere homozygous for a cystic fibrosis mutation for which onlythe mother was heterozygous, and one because he was homozygousfor a rare COL1A2 mutation. We investigated 35 patients witheither the Silver-Russell syndrome or primordial growth retardationand their parents with PCR markers to search for uniparentaldisomy 7. Four of 35 patients were found to have maternal disomy,including three with isodisomy and one with heterodisomy. Thedata confirm the hypothetical localization of a maternally imprintedgene (or more than one such gene) on chromosome 7. It is suggestedto search for UPD 7 in families with an offspring with sporadicSilver-Russell syndrome or primordial growth retardation.     

Genetic relationship between Streptococcus pneumoniae isolates from nasopharyngeal and cerebrospinal fluid of two infants with Pneumococcal Meningitis

The molecular epidemiology of Streptococcus pneumoniae isolates from carriage and cerebrospinal fluid (CSF) concurrently recovered from the same individual has not yet been reported. By using pulsed-field gel electrophoresis, we demonstrated the genetic linkage among strains from CSF and nasopharynges of two children with pneumococcal meningitis.     

Group‐specific component (GC) in curiaú and pacoval,two african‐derived brazilian populations

The group‐specific component (GC) system is of interest in anthropological genetic studies because the distribution of its subtypes distinguishes among major ethnic groups. The GC system was analyzed in Curiaú and Pacoval, two remnant Quilombo populations (African‐derived populations) from the Brazilian Amazon. There was no significant statistical difference in allelic frequencies between the two populations or between them and three other African‐derived Brazilian populations (Mimbó, Sítio Velho, and Gaucinha in Northeastern Brazil). These populations share similarities among themselves and with African populations (high frequencies of GC*1F and lower frequencies of GC*1S), which may reflect the influence of a high level of African contribution to their formation, but there is a clear difference between them and Europeans and South American Indians. It is suggested that the GC system is a useful marker for studying relationships between single populations and major ethnic groups, but does not discriminate between populations which share the same parental stock. Am. J. Hum. Biol. 13:718–720, 2001. © 2001 Wiley‐Liss, Inc.     

The effects of communication skills training on patients' participation during medical interviews

Recent models of physician-patient communication emphasize information exchange in promoting partnership. Although considerable attention has been given to physicians' information exchange, little research has examined patients' communication contributions. The purpose of this research was to test the effectiveness of a training booklet designed to enhance patients' communication skills in information exchange. A nested design was used, such that 25 physicians each saw six patients, two patients in each of three communication skills interventions (i.e. trained, informed, control). The dependent variables included several discourse categories designed to assess patients' information seeking, provision, and verifying. Results indicate that trained patients engaged in more effective and efficient information seeking, provided physicians with more detailed information about their medical condition, and used more summarizing utterances to verify information they received from physicians. Additionally, dyads consisting of trained patients demonstrated a more patient-controlled style of communication than did dyads consisting of informed or untrained patients.     

Corticospinal excitability and sleep: a motor threshold assessment by transcranial magnetic stimulation after awakenings from REM and NREM sleep

Transcranial magnetic stimulation (TMS) is a recently established technique in the neurosciences that allows the non-invasive assessment, among other parameters, of the excitability of motor cortex. Up to now, its application to sleep research has been very scarce and because of technical problems it provided contrasting results. In fact delivering one single suprathreshold magnetic stimulus easily awakes subjects, or lightens their sleep. For this reason, in the present study we assessed motor thresholds (MTs) upon rapid eye movement (REM) and non-rapid eye movement (NREM) sleep awakenings, both in the first and in the last part of the night. Taking into account that a full re-establishment of wake regional brain activity patterns upon awakening from sleep needs up to 20-30 min, it is possible to make inferences about the neurophysiological characteristics of the different sleep stages by analyzing the variables of interest immediately after provoked awakenings. Ten female volunteers slept in the lab for four consecutive nights. During the first night the MTs were collected, following a standardized procedure: 5 min before lights off, upon stage 2 awakening (second NREM period), upon REM sleep awakening (second REM period), upon the final morning awakening (always from stage 2). Results showed that MTs increased linearly from presleep wakefulness to REM sleep awakenings, and from the latter to stage 2 awakenings. There was also a time-of-night effect on MTs upon awakening from stage 2, indicating that MTs decreased from the first to the second part of the night. The increase in corticospinal excitability across the night, which parallels the fulfillment of sleep need, is consistent with the linear decrease of auditory arousal thresholds during the night. The maximal reduction of corticospinal excitability during early NREM sleep can be related to the hyperpolarization of thalamocortical neurons, and is in line with the decreased metabolic activity of motor cortices during this sleep stage. On the contrary, the increase of MTs upon REM sleep awakenings should reflect peripheral factors. We conclude that our findings legitimate the introduction of the TMS technique as a new proper tool in sleep research.