A comparative study of bacterial isolates from the urine samples of AIDS and non—AIDS patients in Benue,Nigeria

ObjectiveTo determine the common bacterial causes of urinary tract infection and their antibiotic susceptibility pattern in AIDS patients versus non-AIDS patients.MethodsOne thousand consecutive AIDS patients with signs and symptoms of AIDS and non-AIDS patients (served as control) each on admission were recruited into the study between January 2005 to January 2008, in Federal Medical Center, Makurdi. Urine samples were collected with sterile universal bottles and analysed with appropriate laboratory methods and antibiotic susceptibility test was carried out by disk diffusion technique in accordance with National Committee for Clinical Laboratory Standards (NCCLS, now CLSI) criteria. The results were analysed using SPSS 11.0 statistical software.ResultsUrine samples of AIDS patients with urinary infection had a more spectrum of micro-organisms including Candida organisms, Pseudomonas aeruginosa and Staphylococcus aureus. Ceftriaxone, Ceftazidime or Ciprofloxacin had a remarkably high anti-bacterial activity across the two study groups. A general resistance was recorded in ampicillin, tetracycline and co-trimoxazole. There was no significant difference in antibiotic susceptibility patterns between AIDS and non-AIDS patients (P>0.05).ConclusionsA reduction in unnecessary use of antibiotics as well as infection control should be encouraged in our health facilities.     

Red cells in sickle cell crisis: observations on the pathophysiology of crisis

The pathophysiology of the occurrence and resolution of sickle cell crisis is unknown. The molecular abnormality is constant, while crisis is episodic. In the present study, red cell filterability and sickling with deoxygenation have been measured during sickle cell crises. Recovery from sickle crisis is associated with an increased filterability of the circulating red cell and a decreased susceptibility of the red cell to sickle with deoxygenation (p less than 0.05). The possibility that these changes are responsible for the resolution of crisis is suggested.     

Evaluation of some anthropometric indices for the diagnosis of obesity in pregnancy in Nigeria: a cross-sectional study

Background

Obesity in pregnancy is a global health problem which is associated with poor pregnancy outcomes. The use of weight and height, measured at about ten weeks of gestation, to produce pre-gestational body mass index is recommended for the diagnoses of the condition but limitations abound in under resourced settings.

Objectives

To measure anthropometric indices such as mid upper arm circumference, calf circumference, waist circumference and waist to hip ratio, for identification of obesity in pregnancy.

Methods

Anthropometric measurements were carried out on cohorts of pregnant women from 4 hospitals in Enugu, South-eastern Nigeria.

Results

There were no significant difference in the mean mid upper arm circumference (MUAC) and calf circumference (CC) across the trimester groups. The mean values of waist circumferences, hip circumference and waist to hip ratios changed significantly across the trimesters. The 75^th percentile of MUAC (33 cm) and CC (39 cm) in all trimesters, had sensitivity and specificity of more than 70% for identifying obesity in pregnancy.

Conclusion

MUAC and CC values of 33cm and 39cm respectively might be reliable cut off points for diagnoses of obesity throughout pregnancy in Enugu, Nigeria     

In vivo induction of type 1 and 2 immune responses against protein antigens

Polarization of the immune response towards Th1 or Th2 profiles is under the control of several, not yet well known, mechanisms. The present study was undertaken to investigate whether immune responses generated against major protein antigens, of parasitic (Schistosoma mansoni) and bacterial (Clostridium tetani) origin, present characteristic Th profiles. Mice were immunized with a single dose of S. mansoni 28 kDa glutathione-S-transferase (Sm28-GST) or tetanus toxin fragment c (TTc) in combination with different adjuvants, or Salmonelia typhimurium expressing these antigens as a fusion protein. Antigen- specific IgG isotypes and cytokine mRNA expression in vivo, as well as cytokine secretion after in vitro antigen stimulation were studied. Immunizations with either protein in aluminum hydroxide induced a strong Th2-associated antibody (IgG1) and cytokine (IL-4) response. In contrast, the recombinant S. typhimurium, expressing the TTc/Sm28-GST fusion protein, induced a Th1-like response, associated with the production of IFN-gamma and IgG2a antibodies against both antigens. When complete Freund's adjuvant was used, a non-polarized profile was observed, characterized by expression of both IL-4 and IFN-gamma, as well as strong specific IgG1 and IgG2a antibody responses. These results indicated that some protein antigens play a weak role in polarizing the immune response and that contrasting cytokine profiles could be induced against the same antigen, depending on the adjuvant employed.      

A Tetraspecific VHH-Based Neutralizing Antibody Modifies Disease Outcome in Three Animal Models of Clostridium difficile Infection

Clostridium difficile infection (CDI), a leading cause of nosocomial infection, is a serious disease in North America, Europe, and Asia. CDI varies greatly from asymptomatic carriage to life-threatening diarrhea, toxic megacolon, and toxemia. The incidence of community-acquired infection has increased due to the emergence of hypervirulent antibiotic-resistant strains. These new strains contribute to the frequent occurrence of disease relapse, complicating treatment, increasing hospital stays, and increasing morbidity and mortality among patients. Therefore, it is critical to develop new therapeutic approaches that bypass the development of antimicrobial resistance and avoid disruption of gut microflora. Here, we describe the construction of a single heteromultimeric VHH-based neutralizing agent (VNA) that targets the two primary virulence factors of Clostridium difficile, toxins A (TcdA) and B (TcdB). Designated VNA2-Tcd, this agent has subnanomolar toxin neutralization potencies for both C. difficile toxins in cell assays. When given systemically by parenteral administration, VNA2-Tcd protected against CDI in gnotobiotic piglets and mice and to a lesser extent in hamsters. Protection from CDI was also observed in gnotobiotic piglets treated by gene therapy with an adenovirus that promoted the expression of VNA2-Tcd.     

Isolation of Extracellular Recombinant Fragment of Rat Connexin-43

Analysis of membrane topology of connexin-43 (Cx-43) made it possible to determine one of its extracellular fragments (E2): Q173-1208. The nucleotide sequence of this fragment was cloned into pCBDQ and pHPML vectors containing the sequences of calmodulin-binding domain (CBD) and HPML-domain of Ca-ATPase of human hPMCA4b cells plasma membrane. This yields two chimeric proteins with N-terminal 6-histidine motif containing the extracellular fragment Cx43 E2 and one of hPMCA4b domains (Cx43-CBD and Cx43-HPML). The latter were inserted into the recombinant polypeptide to improve solubility and enhance immunogenicity of the product. Affinity-purified on Ni-NTA agarose recombinant Cx43-CBD was used for immunization of mice and obtaining of monoclonal antibodies. Primary selection of clones was carried out by solid-phase IEA with immobilized Cx43-HPML and by immunoblotting with Cx43-HPML. The positive clones were tested immunohistochemically on rat brain sections. This two-stage testing made it possible to select two hybridomas, which produced monoclonal antibodies to Cx43 in native conformation. The resultant antibodies can be used in vitro and in vivo for immunophenotyping of various Cx43-positive cells.