SummaryA study by questionnaire of the incidence of pregnancy heartburn in two groups of Nigerians and one group of Caucasians showed an incidence of 9·8 per cent in all Nigerians as against 78·8 per cent in Caucasians. The difference was highly significant (x2= 102·75; P<0·0001). An oesophageal manometric study of the lower oesophageal sphincter in 12 non‐pregnant women and in 12 pregnant Nigerians (10 without heartburn and 2 with heartburn) showed that the mean lower oesophageal sphincter pressure (±SD) in the pregnant patients without heartburn was 20·1 ±7·0 mm Hg as against 17·9 ±7·0 in the non‐pregnant women. While one pregnant subject without heartburn had a lower oesophageal sphincter which was partially displaced into the thorax, none of the non‐pregnant women had such sphincter displacement. The two pregnant women with heartburn had low resting sphincter pressures and in both of them the sphincters were partially in the thorax. It is argued that pregnancy heartburn is due to the displacement of the lower oesophageal sphincter into the negative pressure environment of the thorax where the sphincter is less capable of resisting reflux. It is also argued that pregnancy heartburn is commoner in Caucasians than in Nigerians because the sphincter in non‐pregnant Caucasians is often partly intrathoracic and is thus more easily displaced completely into the thorax by the pregnant uterus.

Penetrating abdominal trauma is on the increase in Calabar. The pattern of injury revealed areas which, when effectively contained, will lead to an improvement in the safety of our environment.

BackgroundThere is a projected increase in lower urinary tract obstruction by 2018, especially in the developing economies of Asia and Africa. However in many of these countries, the problems encountered both by the patients and the clinicians are not well documented. Our aims are, to prospectively analyse the management of urinary retention, the associated difficulties, and complications in our setting, where access to investigative modalities such as Computerize Tomography and Magnetic Resonance Imaging are not available.Patients and MethodsThe study was approved by the University Of Calabar Teaching Hospital ethical committee. A validated Proforma was used to collect data from all patients who were clinically diagnosed with urinary retention based on history, and physical examination, from July 2009 to June 2010. Data collected from the 1st of July 2009 to the 30th of June 2010, include demographics, findings on physical examination, previous medical history and co-morbid conditions. The results of investigations done such as: urinalysis, full blood count, electrolytes, urea and creatinine, intravenous urography, trans- abdominal ultrasonography, chest X-ray and histology of trans-rectal biopsies of the prostate . The total number of new patients seen, including those with urinary retention during the study was documented. The retentions were also classified into acute and chronic. All the patients were followed up throughout the study. The data was analysed using Epi-Info statistical program version 3.4 of 2007 to analyse the data, estimating averages, mean, median and percentages. RESULTS: The total number of new patients seen, including those with urinary retention was Seventy thousand, one hundred and thirty nine (70,139).Of this number, hundred and fifty nine (0.23%), presented with urinary retention; 145 (91.2%) were acute, and14 (8.8%) were chronic. The male: female ratio was 39:1.The patients ages ranged from 4 to 94 years, with a mean of 53.7±11.2. Seventy seven [48.4%] of them were in the 6th and 7th decades of life. The common causes were; prostatic diseases [BPH and cancer of the prostate] 77.0%, infections 75.8%, trauma 12.1%, and congenital 12.1%. Urinary retention was relieved by: indwelling urethral catheterization [IUC] 120 patients (75.5%), supra- pubic cystostomy [SC] 34 (21.4%) and intermittent urethral catheterization [IC] 5 (3.1%). The most frequently encountered complications include pyuria (18.2%), pericatheter sepsis 17.5%, and haemorrhage during change of catheter 16.8% [figure 2].Figure 2Complication after one week bladder drainageConclusionLower urinary retention is common in our environment. The management is appropriate and standard. The man power and facilities are inadequate, and requires urgent improvement.

In this research study, Scheffe's second degree polynomial based model was adapted for the optimization of the mechanical properties of a five component concrete. Here, rice husk ash which is derived from solid waste and contains high quantity of aluminosilicates which makes it a pozzolanic material is used as the fifth component in the concrete mixture. Applying Scheffe's statistical simplex methodology, the mixture formulations; a total of ninety concrete cubes of 150 × 150 × 150 mm dimension were produced including the control points used for testing the adequacy of the model. The concrete sample were cured for 28 days before crushing test is carried out to obtain its compressive strength. The maximum compressive strength of 33.45 N/mm 2 was achieved with a corresponding mix ratio of 0.60:0.65:1.30:1.60:0.35 for fraction of water, cement, fine aggregate, coarse aggregate and rice husk ash respectively. The Scheffe's model equation developed is Ŷ = . The formulated mathematical model was validated and a suitable relationship was observed between the experimental and predicted values based on the outcomes of student t test and analysis of variance. The model can predict the compressive strength of rice husk ash blended cement concrete so as to inform early decision making when used as construction material.