Schizencephaly: diagnosis and progression in utero

Schizencephaly is an unusual condition of obscure etiology. Most theories of pathogenesis postulate an in utero insult leading to maldevelopment rather than destruction of brain. The cause has most often been described as vascular or idiopathic dysgenesis. The authors report a case in which two in utero ultrasound (US) examinations performed at 31 and 36 menstrual weeks demonstrated progressive deterioration of the relatively narrow, symmetrical clefts connecting the lateral ventricles with the subarachnoid space into broad defects that corresponded to the entire distribution of the middle cerebral arteries. The findings in this case document progressive destruction of brain tissue in utero and are consistent with a vascular cause rather than a failure of formation of portions of the cerebral mantle.     

Jordanian undergraduate nursing students' perceptions of effective clinical teachers

Clinical teaching is a dynamic process that occurs in a variety of sociocultural contexts. The quality of student-teacher interaction in the clinical field can either facilitate or hinder the students' learning in the clinical area. This paper presents the results of a study to explore Jordanian undergraduate nursing students' perceptions of effective clinical teacher characteristics. The results showed that overall, the nursing students rated the professional competence of the clinical teacher as the most important characteristic, which when compared to the Western population was different. When male and female nursing students' perceptions were compared, no significant differences were found. However, responses of nursing students from the three academic years differed significantly in that second-year students rated the clinical teachers' relationship with students as most important and fourth-year students rated personal qualities of the clinical teachers as most important. The results were significant in that they were congruent with the students' level of education and most importantly, their cultural beliefs and values about education.     

Differential effects of amino acids on the isolated perfused rat kidney

1. The direct effects of individual amino acids, including glycine (a neutral amino acid), L-glutamic acid (an acidic amino acid), L-leucine (a neutral, branched-chain amino acid) and L-arginine (a basic amino acid), on renal function were compared with a mixed amino acid solution by using the isolated rat kidney perfused with a physiological saline solution containing 6.7% (w/v) albumin and a basal level of 2 mmol/l mixed amino acids. 2. In a control series, the renal perfusate flow was stable but the glomerular filtration rate, as measured by [14C]inulin clearance, declined with time. A stable glomerular filtration rate could be obtained by increasing the basal perfusate amino acid concentration to 14 mmol/l. 3. The addition of 6 mmol/l mixed amino acids produced a sustained increase in renal perfusate flow and an increase in [14C]inulin clearance, reversing its time-dependent fall. Sodium reabsorption was enhanced, but, unlike the control series, no increase in fractional albumin excretion was obtained. 4. Renal perfusate flow was increased by glycine (6 mmol/l), L-arginine hydrochloride (6 mmol/l) and sodium glutamate (6 mmol/l) but remained unaffected by L-leucine. The vasodilatation induced by L-arginine hydrochloride and sodium glutamate was not sustained. 5. The time-dependent fall in [14C]inulin clearance was prevented by glycine, L-arginine and glutamic acid, but not by L-leucine. L-Arginine hydrochloride, like the mixed amino acid solution, produced a significant increase in [14C]inulin clearance.(ABSTRACT TRUNCATED AT 250 WORDS)     

An oligosaccharide-based HIV-1 2G12 mimotope vaccine induces carbohydrate-specific antibodies that fail to neutralize HIV-1 virions

The conserved oligomannose epitope, Man₉GlcNAc₂, recognized by the broadly neutralizing human mAb 2G12 is an attractive prophylactic vaccine candidate for the prevention of HIV-1 infection. We recently reported total chemical synthesis of a series of glycopeptides incorporating one to three copies of Man₉GlcNAc₂ coupled to a cyclic peptide scaffold. Surface plasmon resonance studies showed that divalent and trivalent, but not monovalent, compounds were capable of binding 2G12. To test the efficacy of the divalent glycopeptide as an immunogen capable of inducing a 2G12-like neutralizing antibody response, we covalently coupled the molecule to a powerful immune-stimulating protein carrier and evaluated immunogenicity of the conjugate in two animal species. We used a differential immunoassay to demonstrate induction of high levels of carbohydrate-specific antibodies; however, these antibodies showed poor recognition of recombinant gp160 and failed to neutralize a panel of viral isolates in entry-based neutralization assays. To ascertain whether antibodies produced during natural infection could recognize the mimetics, we screened a panel of HIV-1-positive and -negative sera for binding to gp120 and the synthetic antigens. We present evidence from both direct and competitive binding assays that no significant recognition of the glycopeptides was observed, although certain sera did contain antibodies that could compete with 2G12 for binding to recombinant gp120.     

Entry screening to delay local transmission of 2009 pandemic influenza A (H1N1)

Background  

After the WHO issued the global alert for 2009 pandemic influenza A (H1N1), many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission.     

Urogenital tuberculosis in immunocompromised patients

Objective  Compare the clinicoradiological presentation of urogenital tuberculosis (UGT) between immunocompromised and nonimmunocompromised patients. Patients and methods  Eighty patients diagnosed with UGT were divided into two groups: eight immunocompromised patients (four with acquired immunodeficiency syndrome [AIDS], and four renal transplant patients on immunosuppressive therapy) and 72 nonimmunocompromised patients. The groups were compared as for age, signs and symptoms, diagnostic approach, pattern of urogenital organ involvement, and early specific mortality (within 6 months from diagnosis). Results  AIDS patients were younger (median age 26 years, range 16–38 years), and renal transplant patients were older (median age 51.5 years, range 45–57 years), compared with the nonimmunocompromised subjects (median age 35 years, range 12–75 years). Immunocompromised patients had greater frequency of fever (87.5% versus 43.1%, P = 0.024), lower frequency of storage symptoms (37.5% versus 76.4%, P = 0.033), shorter length of disease (<6 months: 87.5% versus 2.8%, P < 0.001), and larger frequency of disseminated tuberculosis (62.5% versus 18.1%, P = 0.012). Predominantly parenchymatous renal involvement was more frequent in immunocompromised patients (87.5% versus 6.2%, P < 0.001), who also had lower frequency of stenosis of the collecting system (12.5% versus 93.8%, P < 0.001) and contracted bladder (12.5% versus 65.3%, P = 0.001). Conclusions  UGT has a different clinicoradiological presentation in immunocompromised patients, with predominance of systemic symptoms, disseminated tuberculosis, multiple parenchymatous renal foci, and lower frequency of lesions of the collecting system. In the context of immunosuppression, UGT behaves as a severe bacterial infection, with bacteremia and visceral metastatic foci.