Demographics of tonsillar hypertrophy among sickle cell disease patients in calabar.

Background: Sickle cell disease (SCD) is the most common genetic disorder, with Africa bearing the highest burden. In this cohort study, sickle cell subjects are immunocompromised and predisposed to recurrent infections and tonsillar hypertrophy, especially in children. Subsequently, tonsillar hypertrophy leads to sleep-disordered breathing (SDB) with resulting hypoxemia, hypercapnia, and acidosis, raising the risk of HbS polymerization and, consequently, vaso-occlusive phenomena and other complications. Aims: This study aimed to compare tonsillar hypertrophy between sickle cell patients and controls. Materials and Methods: A cross-sectional descriptive study was conducted at, University of Calabar Teaching Hospital, Calabar from September 2019 to September 2021. The cohort of the study was an SCD patient confirmed using hemoglobin electrophoresis at the hematology laboratory of University of Calaabr teaching hospital and recruited via the adult and pediatric hematology unit of University of Calabar teaching hospital, and Calabar sickle cell club. The data were analyzed using Microsoft Excel and IBM Statistical Package and Service Solution (SPSS) version 22. Results: Using Brodsky's grading, the prevalence of grade 3 and 4 hypertrophic tonsils in sickle cell subjects was 41.6% but 17.3% in control. The age range of 0-25 years was the most frequently affected with the peak at 0-5 years. The males among the sickle cell subjects were slightly more affected than the females (M: F =1.2:1), while the females were slightly more in the control (M: F =1:1.1). Conclusions: Hypertrophic tonsils affect control and SCD, but the obstructive grades are commoner in genotypes SCD- Sickle cell disease Haemoglobin SS, SC and AA.

Preschool vision screening: a prospective comparative evaluation.

We have reviewed the results of a pilot study of preschool screening by orthoptists for vision defects which was introduced in Newcastle in 1987. We have compared the visual outcomes, at age 7 years, of children who were screened at age 3 years by either orthoptists, health visitors or general practitioners in three matched, geographically defined cohorts. Manifest, large angle strabismus presented at the same age, and in roughly equal numbers in each cohort. Orthoptic screening detected many more cases of amblyopia associated with microtropia and anisometropia, but the b overall amblyopia prevalence at age 7 years was similar in each cohort. This study does not provide evidence to support the nationwide introduction of primary orthoptic preschool vision screening, and highlights the need for a prospective treatment trial of amblyopia associated with microtropia and anisometropia.

Expression cloning and antigenic analysis of the nucleocapsid protein of equine arteritis virus.

A series of recombinant fusion proteins derived from equine arteritis virus (EAV) open reading frame (ORF) 7 have been used to define the immunoreactive region of the viral nucleocapsid (N) protein. Reactivities of recombinant N fusion proteins with post-infection equine sera in immunoblots and ELISAs indicate that the major nucleocapsid protein epitope is located within amino acid residues 1-69. In ELISAs two recombinant nucleocapsid fusion proteins containing residues 1-69 (rN1-69) and 1-28 (rN1-28) discriminated between pre- and post-infection, and pre- and post-vaccination serum samples. Additionally rN1-69 and rN1-28 detected seroconversions following vaccination with a killed virus preparation, even in the absence of a detectable virus neutralising response. Although a good correlation existed between virus neutralising antibody and rN1-69 ELISA positive values in post-infection sera, all the rN proteins failed to induce any virus neutralising response in immunised rabbits.

Development and evaluation of an ELISA using recombinant fusion protein to detect the presence of host antibody to equine arteritis virus.

A recombinant glutathione-S-transferase fusion protein expressing amino acids 55-98 of equine arteritis virus (EAV) GL (rGL 55-98) was tested in an ELISA for its ability to detect serum antibodies to EAV. Host antibodies induced following EAV infection bound the recombinant antigen by ELISA. The ELISA specificity and sensitivity were determined with a panel of equine sera including postinfection and postvaccination samples. A good correlation existed between EAV neutralizing antibody titers and ELISA absorbance values (r = 0.827). The sensitivity and specificity of the ELISA were 99.6 and 90.1%, respectively, compared with EAV neutralization test and the recombinant antigen did not crossreact in ELISA with equine sera directed against other common equine respiratory viruses. Three post-EAV infection equine sera raised against different EAV isolates reacted strongly in the ELISA, as did two equine sera raised against EAV vaccines, indicating that the viral epitope was conserved between the viruses tested. Following vaccination with an inactivated whole virus vaccine, antibody detected with the recombinant antigen ELISA preceded the development of a virus-neutralizing response. The study demonstrates the potential application of rGL 55-98 as a diagnostic antigen.

Chronic tonsillar herniation and Crouzon's syndrome.

Patients born with craniofacial syndromes such as Crouzon's syndrome will often develop hydrocephalus after their initial craniofacial reconstructive procedures. We have treated 10 patients with Crouzon's syndrome; 5 patients required a shunting procedure after cranial remodeling. Each of these 5 shunted patients later demonstrated chronic tonsillar herniation on magnetic resonance imaging studies. One of these patients exhibited signs of pseudotumor cerebri and 1 had a spastic quadriparesis. Of the 5 patients who did not require a shunt, none displayed chronic tonsillar herniation. Our evidence suggests that jugular foramen stenosis produces an increased cerebral venous turgor that leads to a cerebrospinal fluid absorption defect and hydrocephalus. After the hydrocephalus is treated the increased venous turgor remains and provides the driving force for the development of chronic tonsillar herniation.

Preschool vision screening.

Although a good case for preschool screening for vision defects can be made there is very little evidence that existing programmes are effective in practice. A comparative trial of three different methods of preschool vision screening is described. Some 7000 children initially aged 5 months (younger cohorts) and 30 months (older cohorts) in three matched areas entered the trial during 1987. During 18 months of follow up new visual and ocular defects among these children were ascertained through ophthalmology outpatients and from optician records. Screening at 35 months by an orthoptist based in the community is superior to conventional health visitor surveillance at 30 months and to an agreed programme of primary care screening for squint at 30-36 months as judged by screening sensitivity (100% v 50% v 50%) and the incidence of treated target conditions (17 v 3 v 5 per 1000 person years). A notable feature in the area served by the orthoptist is that 13 children received treatment for straight eyed visual acuity loss from among 1000 children whereas there were no such cases among 2500 in the comparison areas. In the younger cohorts (that is, screening at age 5-9 months) all three programmes showed equally poor results, only one of the eight treated target conditions arising from all 3500 younger children being screen detected.