Age-specific Serum Prostate Specific Antigen Ranges Among Apparently Healthy Nigerian Men Without Clinical Evidence of Prostate Cancer.

INTRODUCTION: Serum prostate specific antigen (PSA) levels increase with age and varies among different races and communities. The study was aimed at defining the age-specific reference ranges of serum PSA in our environment. METHODS: We evaluated the relationship between age and serum PSA levels and the age-specific reference ranges of serum PSA among civil servants in Lagos, who underwent routine medical checkups. Criteria for inclusion were men who have no lower urinary tract symptoms, normal digital rectal examination and serum PSA ≤ 20 ng/ml. SPSS Statistic 21 was used for data evaluation and the mean, median, 95(th) percentile PSA levels were estimated. Pearson's correlation was used to examine the relationship, and P < 0.05 was considered significant. RESULTS: 4032 men met the criteria for inclusion in the evaluation. The mean age was 51.6 (range 40-70) years, and there was a strong correlation between serum PSA levels and age (r = 0.097, P < 0.001). PSA ranges of 0-2.5, >2.5-4.0, >4.0-10, and >10 ng/ml were found in 3218 (80%), 481 (12%), 284 (7%), and 52 (1%) men, respectively. The mean, median and the 95(th) percentile PSA for the overall group were 1.84, 1.33, and 5.2 ng/ml respectively. However the 95(th) percentile PSA levels for men aged 40-49, 50-59, and 60-70 years were 4.78, 5.47, and 8.93 ng/ml respectively. CONCLUSION: The age-specific PSA levels among Nigerian men for each age group is higher than what was described for men in the Western world. These reference ranges of serum PSA should be considered for men aged ≥40 years in our environment.

The effect of a membrane dialyzer during hemodialysis on the antioxidant status and lipid peroxidation of patients with end-stage renal disease.

Renal failure is accompanied by oxidative stress, which is caused by enhanced production of reactive oxygen species (ROS) and an impaired antioxidant defense. We studied 73 hemodialysis (HD) patients (39 males and 34 females) aged 24-75 years; the patients were randomized into two subgroups according to the type of hemodialysis membrane (35 patients were dialyzed on cellulose and 38 patients on polysulfone F7/F9 membrane dialyzers) and we assessed their antioxidant and lipid peroxidation status levels. The total antioxidant status (TAS) levels including whole blood levels of malondialdehyde (MDA) and glutathione (GSH); glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities were measured, before and after hemodialysis. The MDA levels significantly increased 52.0% and 16.9% post dialysis among the cellulose and the polysulfone dialyzer users, respectively, (P<0.05). The TAS levels significantly decreased, 22.0 and 16.5% in the cellulose and polysulfone dialyzer users, respectively, (P<0.05). The erythrocyte SOD activity decreased 25.1 and 19.1% in the cellulose and the polysulfone dialyzer users, respectively, (P<0.05). The GSH concentrations, post dialysis, decreased 49.9 and 6.8% in the cellulose and polysulfone dialyzer users, respectively, (P<0.05). In contrast, the erythrocyte activity of CAT, post dialysis, increased 15.0 and 37.3% in the polysulfone and the cellulose dialyzer users, respectively, (P<0.05). We conclude that the type of the dialysis membrane affects the oxidative status after HD with possible consequences on patient morbidity and mortality.

Relationship between liver function tests and thyroid hormones in thyroid disorders.

AIMS AND OBJECTIVES: To evaluated the effect of thyroid dysfunction on liver function tests and if there is any correlation between them. MATERIALS AND METHODS: A total of 68 subjects (40 hyperthyroid and 28 hypothyroid) between the ages of 20-60 years old and 40 healthy euthyroid volunteers of the same age groups were studied. Plasma albumin, bilirubin (total and conjugated), thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone (TSH); activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT) were estimated in the plasma of the participants. RESULTS: Plasma concentration of Total .bilirubin and liver enzyme activities increased significantly in both hyperthyroid and hypothyroid subjects. The positive correlations between thyroid hormones and liver enzymes in hyperthyroid subjects were negative in hypothyroid subjects and vice-visa. CONCLUSION: It can be concluded that both hyperthyroidism and hypothyroidism altered liver function tests. It is thus recommended that liver function tests interpretation in thyroid dysfunction should be with caution.

Adrenocortical function in Nigerians with human immunodeficiency virus infection.

OBJECTIVE: This study sets out to determine the prevalence of adrenocortical insufficiency in persons with HIV infection by determining the response to low-dose (1 µg) ACTH stimulation. DESIGN: An experimental study involving people with HIV infection and healthy people. SETTING: The study group and the controls were recruited from the Lagos University Teaching Hospital (LUTH). PARTICIPANTS: forty-three newly diagnosed and treatment naïve persons with HIV (23 males and 20 females) and 70 (35 males and 35 females) HIV negative subjects completed the study. INTERVENTION: One µg Synacthen was given intravenously to stimulate the adrenal glands. MAIN OUTCOME MEASURES: Blood was collected for basal cortisol levels and 30 minutes after the injection of ACTH. Cortisol was assayed using ELISA. RESULTS: The mean basal cortisol was 154.9 ± 27.2 nmol/L and 239.9 ± 31.6 nmol/L (p<0.001); while the 30-minute post ACTH test cortisol level was 354.8 ± 19.9 nmol/L and 870.9 ± 163.5 nmol/L (p<0.001) and the increment was 100.0 ± 17.2 nmol/L and 588.8 ± 143.4 nmol/L (p<0.001) in HIV and healthy subject group respectively. Using the diagnostic criteria derived for the diagnosis of adrenocortical insufficiency in this study (30 minute cortisol level <380.2 nmol/L and increment from basal to stimulated cortisol level <158.5 nmol/L); fifteen (34.8%) persons with HIV had adrenal insufficiency. CONCLUSION: Adrenocortical insufficiency is common in persons with HIV infection, occurring in about 34.8% of patients studied. Clinically evident adrenocortical insufficiency is uncommon in persons with HIV.

Effect of obesity on serum prostate-specific antigen in Nigerian men.

OBJECTIVE: Lower serum total prostate-specific antigen (PSA) levels (tPSA) have been reported in obese men. It has not been confirmed if this association truly exists in all ethnic groups. Thus, we evaluated the relationship between tPSA and obesity among Nigerian men. METHODS: Men aged ≥ 40 years with tPSA <20 ng/ml and no known prostatic disease were involved. Obesity was defined using the body mass index (BMI) and waist to hip ratio (WHR). Multivariate linear regression was used to investigate the relationship between tPSA and either BMI or WHR. The odds of having abnormal tPSA were estimated using logistic regression. RESULTS: A total of 3,191 men participated, and 3,049 (95.6%) were eligible for analysis. A BMI ≥ 25.0 and a WHR ≥ 0.9 were found in 47.7 and 64.6%, respectively. tPSA was significantly associated with age (p < 0.001) and digital rectal examination status (p < 0.001). Multivariate linear regression analysis showed no relationship between tPSA and obesity (BMI, p = 0.581; WHR, p = 0.160). Adjusting for age and digital rectal examination status, logistic regression showed no significantly observable trend of having a tPSA level greater than thresholds for men with a BMI ≥ 25 or a WHR ≥ 0.9 when compared with normal BMI or WHR, respectively. CONCLUSION: Although overweight and obesity were common among healthy Nigerian men, there was no associated tendency towards lower serum tPSA.

Adrenocortical function in Nigerian patients with pulmonary tuberculosis (PTB).

Addison's disease was frequently consequent upon affectation of the glands by tuberculosis. Pulmonary Tuberculosis (PTB) is still very common in Nigeria but no report on the functional status of the adrenal cortex in patients with PTB in Nigeria exists. It is very important to note that subclinical adrenocortical failure in tuberculosis is an entity that should be considered as cortisol deficiency could be responsible for unexpected sudden death in this category of patients. This study sets out to determine the prevalence of subclinical adrenocortical failure in persons with PTB by determining the response to low-dose (1 ìg) ACTH stimulation. Forty four persons with newly diagnosed sputum-positive PTB and treatment naive, (23 males and 21 females, mean age 34.4 +/- 11.3 years, and mean body mass index (BMI) of 18.9 +/- 2.9 kg/m2) completed the study. Of the one hundred healthy volunteers recruited as control subjects, 70 persons (35 males and 35 females, mean age 38.1 +/- 12.5 years, BMI 24.1 +/- 3.7 kg/m2) completed the exercise. There was no statistically significant difference in the basal cortisol of healthy subjects and persons with PTB (239.9 vs. 229.1 nmol/L, p = 0.661). The thirty minute response to ACTH stimulation test and increment were significantly lower in persons with PTB than in healthy subjects. Adrenocortical insufficiency, mostly at the subclinical level, is common in persons with PTB infection, occurring in about 23% of patients. We therefore recommend that basal cortisol levels should not be used to detect adrenocortical insufficiency; rather stimulation tests should be used to exclude or confirm suspected adrenocortical insufficiency in patients with PTB.

Effect of hemodialysis on total antioxidant status of chronic renal failure patients in government hospitals in Lagos Nigeria.

BACKGROUND: Renal failure is accompanied by oxidative stress, which is caused by enhanced production of reactive oxygen species and impaired antioxidant defense. AIM: To assess the effect of hemodialysis (by cellulose membrane dialyzer) on plasma total antioxidant status and lipid peroxidation of patients in chronic renal failure before and after dialysis. OBJECTIVE: The finding would serve as guide to administration or otherwise of supplementary therapeutic antioxidant before or after hemodialysis. Also, it will assist in the choice of antioxidant impregnated over the conventional non-impregnated dialyzer membrane. MATERIALS AND METHODS: Twenty-five patients (14 men and 11 women, aged 24-75 years; median 61) with end-stage renal failure who were undergoing hemodialysis for the first time were recruited. Plasma level of potassium (K+), sodium (Na+), blood urea nitrogen (BUN), creatinine, total antioxidant status (TAS), and lipid peroxidation (MDA) were measured, before and after hemodialysis. RESULTS: The mean ± SD of plasma level of TAS (1.10 ± 0.3 mmol/L trolox Eq) for males and (1.09 ± 0.2 mmol/L trolox Eq) for females postdialysis were significantly reduced ( P < 0.05) in comparison with (1.72 ± 0.4 mmol/L trolox Eq) for males and (1.83 ± 0.7 mmol/L trolox Eq) for females predialysis, respectively. However, the mean ± SD plasma level of MDA (6.03 ± 0.4 nmol/ml) for males and (6.71 ± 0.7 nmol/ml) for females were significantly increased postdialysis ( P < 0.01) compared to predialysis (3.98 ± 0.8 nmol/ml) for males and (4.05 ± 0.9 nmol/ml) for females, respectively. CONCLUSIONS: Based on the outcome of this study, it is suggested that antioxidant-impregnated dialysis membranes and/or exogenous supplementary antioxidant would be beneficial to patients with chronic renal failure. Removal of reactive oxygen species could improve the health and general quality of life of uremic patients.

Comparison of low dose and standard dose adrenocorticotropin stimulation tests in healthy Nigerians.

Hypothalamo-pituitary-adrenal (HPA) axis dysfunction is a potentially life-threatening condition. It is of paramount importance that safe, reliable diagnostic tests be available to identify patients at risk for adrenal insufficiency. The 250 microg Adrenocorticotropic hormone (ACTH) stimulation test is commonly used to assess adrenocortical function. The 250 microg dose is supraphysiological, therefore several investigators, over the years, have used 1 microg ACTH stimulation test to assess adrenocortical function. The aim of the study was to compare the response of healthy adult Nigerian subjects to the 250 microg and 1 microg ACTH tests. Ten healthy subjects, five males and five females, aged between 20-60 years, (mean, 38.7 years) participated in this study. They all had normal medical histories and physical examinations, were nonsmokers, and had never received any type of glucocorticoid therapy. Serum chemistries, full blood counts, erythrocyte sedimentation rate, were all within normal limits. Both low dose ACTH test and standard dose ACTH test were performed on the 10 subjects in a randomized order on different days.There was no statistically significant difference in mean serum cortisol levels between the two test doses at 30 minutes (928.4 vs 929.8 nmol/L). There was a strong correlation between 30-minute cortisol responses to 1 microg and 250 microg ACTH stimulation tests, r = 0.999; p < 0.001. In agreement with other published data, our study confirms that 1 microg ACTH stimulates adrenocortical secretion in normal subjects in the period 30 minutes post injection comparable to 250 microg ACTH testing.

Serum concentration of acute phase protein and lipid profile in HIV-1 seropositive patients and its relationship to the progression of the disease.

AIMS AND OBJECTIVES: To evaluate the effect of HIV-1 infection and its progression on lipid profiles, acute-phase proteins and to determine which of the parameters may serve as an early indicator of the progression of HIV infection. MATERIALS AND METHODS: A cross-sectional study was conducted on sixty-two HIV-1 infected subjects attending HIV clinic, the patients consisted of 29 males and 33 females aged between 20-60 years (mean age 31+/- 7 years) who were screened for HIV-1 by ELISA test. Absolute CD4+ T lymphocyte was counted and HIV infected individuals were classified according to the Centre for Disease Control and Prevention (CDC) Criteria; CD4+ counts e"500/mm3 (asymptomatic), CD4+ counts 200-499/mm3 (symptomatic) and CD4+ counts d"199/mm3 (symptomatic) with full blown AIDS. Serum concentrations of total protein, albumin, gamma globulin, acute-phase protein, and lipid profile were determined. RESULTS: There was significantly increased gamma globulin fraction of the serum protein in HIV patients with CD4+ counts of e"500/mm3, 200-499/mm3 and d"199/mm3 when compared with the controls. Serum triglyceride was significantly increased in HIV patients with CD4+ counts of d"199/mm3 only, whereas a significantly decreased serum HDL-cholesterol in HIV patients with CD4+ counts of 200-499/mm3 and d"199/mm3 was found when compared with the controls. Haptoglobin, C-reactive protein and a1-acid glycoprotein were significantly increased in HIV patients with CD4+ counts of 200-499/mm3 and d"199/mm3 when compared with the controls. However, albumin was significantly reduced in HIV patients with CD4+ counts of d"199/mm3 when compared with the controls. There was direct correlation between HDL-cholesterol and the CD4+ counts, on the other hand, an inverse correlation between C-reactive protein, haptoglobin and a1-acid glycoprotein against CD4+ counts was found. CONCLUSION: A decreased HDL-cholesterol had direct correlation with the CD4+ counts in all the stages of HIV infection; however, increased haptoglobin and C-reactive protein had inverse correlation with the CD4+ counts in all the stages of HIV infection. Therefore HDL-cholesterol, C-reactive protein and haptoglobin may serve as indicators of disease progression in HIV infection.

Quinine lowers serum and testicular testosterone in adult Sprague-Dawley rats.

We have earlier demonstrated that quinine (QU) is a testicular toxicant. This present study was aimed at evaluating the effects of QU on both the serum and testicular levels of testosterone (TT) in an attempt to elucidate one of the potential mechanisms of QU-induced testicular toxicity. Thirty adult male Sprague-Dawley rats weighing 180-200g were used and were randomly divided into 3 groups of 10 rats each. Rats in group 1 had distilled water. Rats in group 2 had QU only at the dose of 10 mg/kg body weight per day (5 days in a week) for 8 weeks. Rats in group 3 rats had 10 mg/kg of QU (5 days in week) and 0.05 mg/kg of TT (3 days in a week) for 8 weeks. All the animals were sacrificed at the end of 8 weeks by decapitation. Seminal analysis was done on the tubular fluid aspirated from the caudal epididymides. The two testes were excised, weighed, and volume estimated. One testis of each rat (0.25 g of tissue) was homogenized with Potassium Chloride and TT level determined in the supernatant of the homogenate, while the other testis was processed for histology. Morphometry was carried out by assessing the diameter, cross-sectional area, number of profiles per unit area, length density and numerical density of the seminiferous tubules, and the relative and absolute volume of testicular components. The serum levels of TT in all the animals were also determined at the time of sacrifice. Both the serum and testicular levels of TT in rats administered QU only were significantly (P < 0.001) lower than those of the control and QU plus TT-treated rats. We conclude that QU induces spermatogenic epithelial toxicity by possibly interfering with the steroidogenic function of the Leydig cell.

Ascorbic Acid and Alpha Tocopherol Antioxidant Status of Type 2 Diabetes Mellitus Patients seen in Lagos.

SUMMARY: This study was carried out with the aim of assessing the plasma status of ascorbic acid and alpha-tocopherol in Nigerian type 2 diabetes mellitus patients It was a cross sectional study, made up of 70 type 2 diabetes mellitus patients and 40 healthy controls. The plasma levels of vitamins C and E were measured, so also were the fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1C). Results showed significantly lower plasma levels of vitamin C and vitamin E in the patients, compared with the controls. The correlation studies between vitamins C and E on the one hand, versus (FPG) and HbA1c on the other hand were not contributory.The conclusion from this study, is that, there is a reduction in plasma levels of anti-oxidant vitamins C and E in type 2 DM but this does not have any particular relationship with the levels of FPG or HbA1C. KEYWORDS: type 2 Dm, ascorbic Acid, alpha tocopherol antioxidant status.

Total antioxidant status and lipid peroxidation in HIV-1 infected patients in a rural area of south western Nigeria.

Total serum antioxidant status (TAS) and lipid peroxidation were evaluated in 62 HIV-1 seropositive patients before the commencement of antiretroviral drug therapy. Twenty-four (24) age-marched and apparently healthy HIV-1 seronegative subjects were recruited as control subjects. HIV-1 seropositive patients were classified according to the Centre for Disease Control and Prevention (CDC) Criteria. The mean serum malondialdehyde (MDA) concentrations of 5.58 +/- 0.99nmol/ml and 4.24 +/- 0.80nmol/ml were significantly elevated in HIV-1 infected patients with CD4+ count of <200 lym/mm3 and that of 200-499 lym/mm3 respectively when compared with the control which is 3.37 +/- 0.56nmol/ ml (P<0.001). Whereas when compared with control, the serum MDA concentration of 3.45 +/- 0.48nmol/ml in HIV-1 patients with CD4+ count of >500 lym/mm3 was not significant (P>0.05). In the intra groups comparison serum concentration of MDA were significantly elevated when compared with each other (P<0.001). The mean serum total antioxidant status (TAS) of 1.30 +/- 0.11mmol/L, 1.12 +/- 0.24 mmol/L and 0.95 +/- 0.17mmol/L of HIV- 1 seropositive patients with CD4+ count of >500 lym/mm3, 200-499 lym/mm3 and <200 lym/mm3 respectively were significantly reduced compared with 1.69 +/- 0.23mmol/L for the control group (P<0.001). Similarly in the intra groups comparison, serum concentration of TAS were significantly reduced when compared with each other (P<0.001). The weight of 54.81 +/- 5.13 Kg for HIV-I seropositive patients with CD4+ count of <200 lym/mm3 was significantly reduced when compared with 69.17 +/- 4.38Kg for the control (P<0.05). Our results clearly show that severe oxidative stress occurs in the serum of seropositive patients in comparison with controls, and increases significantly with the progression of disease, i.e. AIDS > symptomatics > asymptomatics > controls. The inclusion of antioxidants in the therapeutic approach in managing HIV- 1 seropositive patients will prevent the additional damage that free radicals could do to such patients.

Plasma magnesium in adult asthmatics at the Lagos University Teaching Hospital, Nigeria.

OBJECTIVE: To determine the plasma magnesium levels in adult asthmatics. DESIGN: Case control study. SETTING: Lagos University Teaching Hospital, Lagos, Nigeria. SUBJECTS: Forty stable asthmatics and thirty five apparently healthy controls. METHODS: Detailed history including drug history was obtained from patients and controls. Fasting venous blood was collected into heparinized tubes from both patients and controls. Plasma magnesium, albumin, calcium and phosphorus were measured using spectrophotometric end point methods. RESULTS: Mean (SD) plasma magnesium concentration of 0.93(0.24) mmol/L in the asthmatics was significantly lower compared to the controls which was 1.15(0.28) mmol/L, p<0.001. There was no significant difference in the plasma albumin, calcium and phosphorus levels between the patients and controls. Plasma magnesium levels correlated with the plasma albumin level (r=0.62) but did not correlate with the duration of disease, peak flow rate and age of patients. There was no gender difference in plasma magnesium levels in the asthmatics. CONCLUSION: Adult Nigerian asthmatics have lower plasma magnesium concentrations compared to healthy controls. This may be of use in future therapeutic management of asthma. A large scale multi-centre study needs to be carried out since this study was done in one hospital.

Laboratory assessment of three glucometers.

The study was designed to assess the technical performance of three common glucometers (Glucometer Elite, Accutrend Alpha, One Touch Basic) marketed in Nigeria. This is with a view to assessing their suitability for use in this environment and to provide an informed opinion on the selection option. Venous blood, capillary blood, serum and plasma were assayed during the study. Precision, accuracy, linearity and effect of haemolysis and haematocrit were carried out on each glucometer. Simultaneous analysis using the laboratory reference method was also carried out where necessary. Intra-assay precision was between 1.4% (Glucometer Elite)-11% (One Touch Basic) while the interassay precision was best for the Accutrend Alpha with a CV of 1.9%. All three glucometers correlated excellently with laboratory values and the %deviation from laboratory values was 0.2-10.5%. The Glucometer Elite was the most portable and used the least volume of blood (5 ul). One Touch Basic Glucometer was the least affected by haemolysis. Haematocrit values less than 50% did not have any effect on the three glucometer readings. The technical performance of these three glucometers were found to be acceptable and are recommended for use by diabetic patients, emergency and intensive care units and antenatal clinics, subject to periodic assessment and calibration.

Plasma magnesium in adult Nigerian patients with epilepsy.

UNLABELLED: The objective of this study was to determine the relationship between plasma magnesium levels and epilepsy. The study was carried out at the Lagos University Teaching Hospital. Plasma magnesium was estimated using the calmigite dye colorimetric method in 45 adults with epilepsy and 35 healthy controls. Plasma concentrations of calcium, phosphorus and albumin were also estimated. The mean plasma magnesium in the patients was 0.98 mm0l/L (0.05) while that in the controls was 1.15 mmol/L (0.28). The mean plasma magnesium in the epileptics was significantly lower than that obtained in the controls (p < 0.001). Age of onset of seizures, seizure frequency and duration of treatment did not influence the plasma magnesium levels. Low plasma magnesium is associated with epilepsy, further studies may determine the influence of anti-epileptic drug therapy on plasma magnesium levels. KEYWORDS: magnesium, seizures, Nigeria.

The lactate dehydrogenases in malignant and non-malignant diseases.

The objective of this paper was to determine different patterns of Lactate Dehydrogenase(LD) isoenzymes in serum, pleural effusions and ascitic fluid collections and their usefulness in the differential diagnosis of malignant and non-malignant diseases. It was a case control study carried out at the Lagos University Teaching Hospital. Forty- six patients with pleural or ascitic fluid collection (male and female, age range between 18 and 65 years) made up of Twenty-two patients with malignant diseases and twenty-four with non- malignant diseases were recruited. Control group comprised 50 apparently healthy subjects of both sexes with age ranging between 18 and 65 years. Serum, pleural and ascitic fluid collections were assayed for total lactate dehydrogenase(LD) and it s isoenzymes. Total LD was estimated using the pyruvate to lactate reaction. LD isoenzyme analysis was estimated by cellulose acetate electrophoresis and stained with formazan. The mean total serum LD activity in the disease groups (malignant and non-malignant) was significantly higher than the mean total serum LD activity in the control group. The pleural fluid LD was highest in patients with empyema thoracis. Five isoenzymes of LD (LD1 - LD5) were present in both control and patient sera. The serum LD1 and LD2 isoenzymes were predominant in the controls. The serum LD4 and LD5 isoenzymes were predominant in the disease groups (malignant and non-malignant). LD4 and LD5 were the predominant isoenzymes in both pleural and ascitic fluids obtained in malignant and non-malignant diseases. Serum LD4 was significantly higher than serum LD5 in non-malignant disease while serum LD5 was significantly higher than serum LD4 in malignant disease. The types of malignancies could not be differentiated by serum and effusion fluid LD isoenzyme pattern. Pleural fluid total LD estimation is useful in monitoring patients on chest tubes and may be used to determine when to insert them. Serum LD4 and LD5 differentiates malignant from non-malignant disease but the effusion LD isoenzyme pattern does not.

Hypothalamic neuropeptide Y mRNA in pregnant, lactating and suckling rats.

Blood glucose, plasma insulin and luteinizing hormone levels were studied in pregnant wistra rats and those in early and late stages of lactation. NPY mRNA was also measured in whole hypothalamic tissue of these rats which were either fed ad libitum or food deprived to 80% of the relative controls. When fed ad libitum, hypothalamic NPY mRNA was not significantly elevated in the pregnant rats (111 +/- 2.1%). By the 5th and 4th days of lactation the mRNA had increased progressively (141 +/- 4.7% of control, p<0.01; 186 +/- 9%, p<0.001) respectively. Blood glucose levels were unchanged in pregnancy and lactation, however, insulin levels dropped significantly by the ]4th day of lactation (control 322.3 +/- 3.2; lactating 298.6 +/- 4.8 pmol/l; p<0.05). Luteinizing hormone was significantly reduced in the lactating rats (control 2.2 +/- 0.21, lactating 0.81 +/- 0.2 ng/ml;p<0.05). In food restriction, NPY mRNA was increased moderately in the non-pregnant state and enormously in late lactation (non-pregnant 157 +/- 21%, lactating 333 +/- 35%, p<0.001). In a lactation, blood glucose was unchanged while plasma insulin and LH were reduced to 20% and 50% of controls respectively (insulin: control 110.3 +/- 2.0; lactating 18.3 pmol/l; LH. control 1.3 +/- 0.1; lactating 0.59 +/- 0.4 ng/ml p<0.01). Orexigenic effect of hypothalamic NPY is possibly responsible for the hyperphagia in lactating. Food restriction and lactation had additive lowering effect on plasma insulin but an additive increase on hypothalamic NPYmRNA. NPY message may be partially responsible for the anovulatory effect of lactation.

Additive effects of lactation and food restriction to increase hypothalamic neuropeptide Y mRNA in rats.

Neuropeptide Y (NPY) is the most powerful appetite stimulant known, and rates of synthesis and release in the hypothalamus correlate closely with nutritional status. Pregnancy and lactation provide an excellent model of physiological hyperphagia. In this study the authors measured food intake, plasma glucose, insulin and luteinizing hormone (LH) and hypothalamic NPY mRNA in rats during pregnancy and in early and late lactation. The effect of food restriction (to 80% of control) during lactation was also studied. Pregnancy resulted in a modest increase in daily food intake over non-lactating controls (controls: 15.6 +/- 0.6 g, pregnant: 19.8 +/- 1.1 g, P < 0.01). During lactation food intake increased dramatically to 355% of non-lactating levels by the 12th day. Insulin and glucose levels were unchanged in lactation, except in the food-restricted animals, when insulin levels were reduced to 49.5 +/- 18.4 pmol/l compared with 215 +/- 55 pmol/l (P < 0.01) in lactating, non-restricted animals, and glucose was reduced to 3.7 +/- 0.2 mmol/l compared with 5.1 +/- 0.2 mmol/l in non-restricted lactating animals. Hypothalamic NPY mRNA was unchanged in pregnancy, moderately increased after 5 days lactation (130 +/- 6.2% of control, P < 0.01) and increased further at 14 days lactation (179 +/- 14%, P < 0.001). The greatest changes occurred in the animals who were food-deprived during lactation, when hypothalamic NPY mRNA levels reached 324 +/- 44% (P < 0.001) of non-lactating levels. Increases in hypothalamic NPY synthesis may be partly responsible for the increase in food intake seen in lactation, but unlike in food deprivation, the increase is not related to circulating insulin, suggesting involvement of other regulatory factors.

Efficiency of the salt flotation technique in the recovery of Ascaris lumbricoides eggs from the soil.

The efficacy of the salt flotation technique using saturated solutions of sodium nitrate (specific gravity 1.30) and zinc sulphate (specific gravity 1.16) for separating Ascaris lumbricoides eggs from clay, loamy and sandy soils has been investigated. Ten samples of each of the egg concentrations of 100, 500, 2500, 5000 and 10,000 eggs/25 g of soil were used for each soil type. Using T-test and ANOVA, the number of eggs recovered from sand was significantly higher than from loam and the number from loam significantly higher than from clay. With sodium nitrate, the maximum egg recovery rate was 25.04% from sandy soil at a concentration of 500 eggs/25 g soil while with zinc sulphate it was 13.88% also from sandy soil and concentration of 500 eggs/25 g soil. While the number of eggs recovered increased with soil egg concentration, the percentage of eggs recovered is inversely proportional to egg concentration. The number of eggs recovered with sodium nitrate was significantly higher than with zinc sulphate solution in the three soil types.