Cut-Off Value of Thyrotropin-Receptor Antibodies in Grave's Disease in Basrah.

BACKGROUND: The diagnosis of Grave's disease (GD) poses a challenge. Thyrotropin-receptor antibodies (TRAb) are the key diagnostic feature of GD, as the American and European Thyroid Associations suggested. AIM OF THE STUDY: This study aims to find a cut-off level of TRAb in GD in Basrah. METHODS: This is a retrospective study that included 617 patients with hyperthyroidism (530 GD and 87 non-Grave's disease (NGD) (thyroiditis or subclinical hyperthyroidism)). The candidates were patients presenting with hyperthyroidism who were referred for TRAb assay, while patients with thyroid carcinoma or nodular thyroid disease, pregnant ladies, and patients who were treated were excluded. RESULTS: The manufacturer cut-off value of 1.75 IU/L had a sensitivity of 88.1%, specificity of 72.4%, positive predictive value (PPV) of 95.1%, and negative predictive value (NPV) of 50.0%. Our data analysis through receiver operating characteristic (ROC) statistics revealed that the optimum cut-off point with the highest total sensitivity and specificity was determined to be 3.95 IU/L, as it had a sensitivity of 76.9%, specificity of 98.8%, PPV of 99.7%, NPV of 41.3%. CONCLUSION: For a more accurate diagnosis of GD, the findings of the present study support the implementation of a higher TRAb cut-off value (3.95 IU/L) than that predefined by the manufacturer (1.75 IU/L).

The Clinical Implications of Anti-thyroid Peroxidase Antibodies in Graves' Disease in Basrah.

Background Graves' disease (GD) is an autoimmune disease, with thyrotropin receptor antibodies (TRAbs) being the most important cause in the pathogenesis. The aim of this study is to assess the clinical significance of anti-TPO Abs in GD. Methods A retrospective study was conducted at the Faiha specialized Diabetes, Endocrine, and Metabolism Center (FDEMC) in Basrah during the period between December 2021 and December 2022. A total of 141 patients with GD were involved in this study, and of them, 97 (68.8%) were women. They were divided into two groups: patients with positive and negative anti-TPO Abs groups. Results Positive anti-TPO Abs were seen in 83 patients (58.9%) with GD. Pretreatment-free thyroxine level (ng/dL) was higher in the anti-TPO Abs positive GD patients than in those with negative antibodies (3.7±0.2 versus 3.0±0.2 with a p=0.021). Similarly, higher TRAb titers (IU/ml) at baseline were also seen in patients with positive anti-TPO Abs (9.8±0.7 versus 6.8±0.8) with a p=0.008. Giraffe appearance on thyroid ultrasound was more common in the group with positive anti-TPO Abs as compared to patients with negative anti-TPO Abs: 20 (87.0%) versus 3 (13.0%) with a p=0.005. A higher anti-TPO Abs titer (IU/mL) was associated with a baseline TRAb level of more than 6.4 IU/mL, and giraffe appearance on thyroid ultrasound (206.5±20.0 p-value<0.0001 and 228.0±35.3 p value=0.007, respectively). Conclusion A positive anti-TPO Abs in GD is associated with a high TRAb titer and free T4 level at baseline, as well as a giraffe appearance on thyroid ultrasound.

Management Outcomes in Males With Hypogonadotropic Hypogonadism Treated With Gonadotropins.

Background Hypogonadotropic hypogonadism is an important cause of male infertility and loss of secondary sexual characteristics. Gonadotropin replacement is mandatory for sexual function, bone health, and normal psychological status. This study is to compare the effectiveness of different gonadotropin therapy modalities in the management of male hypogonadism. Methods A randomized open-label prospective study of 51 patients attended the Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC) with hypogonadotropic hypogonadism, divided randomly into three groups. The first group was treated with human chorionic gonadotropin (hCG) alone, the second group was treated with a combination of both hCG and human menopausal gonadotropin (HMG), while the third group started with hCG alone then followed by combination therapy after six months. Results All modalities of therapy result in a significant increase in mean testicular volume although no clinically significant difference between the groups, but the combination group had the highest increment. The increment in serum testosterone level was statistically significant among the different groups of treatment (p-value < 0.0001). When comparing groups, a higher mean maximum testosterone level (710.4±102.7 ng/dL) was obtained with the combination group followed by the sequential group, with mean maximum testosterone levels (636.0±68.6 ng/dL) (p-value = 0.031). Factors negatively affecting testosterone level include BMI > 30 kg/m2, initial testicular volume < 5 mL, and duration of therapy < 13 months. Conclusions Induction of puberty using recombinant hCG alone is sufficient to induce secondary sexual characteristics, while for fertility issues combination from the start or sequential therapy has better for spermatogenesis. There was no effect of prior exogenous testosterone treatment on final spermatogenesis.

Serum Glucose Measurement after Five to Six Hours is Comparable to Eight Hours Fasting in Ramadan.

Objectives: This study aimed to evaluate whether a shorter fasting duration of five to six hours can be used as an alternative to the usually recommended eight hours for fasting glucose measurement. Methods: This one-month observational, cross-sectional study was conducted during Ramadan (May to June) 2019. It included those attending Faiha Specialized Diabetes, Endocrine and Metabolism Center, Basrah, Iraq; all individuals ate a pre-dawn meal (suhoor) followed by a complete fast for many hours. Two fasting serum glucose (FSG) venous samples were taken; the first was taken five to six hours and the second eight hours after the pre-dawn meal. Participants were divided into two groups: individuals with type 2 diabetes mellitus (T2DM) and those with a normal glucose level. T2DM patients were further subdivided into three groups: those without treatment, those on oral antidiabetic drugs (OAD) and those using insulin and OAD. Results: A total of 200 individuals participated in this study. There was no significant difference found between the mean FSG levels in the first and second samples for those without T2DM (104.5 ± 21.4 mg/dL versus 104.8 ± 12.6 mg/dL; P = 0.80) as well as those with T2DM (235.0 ± 107.0 mg/dL versus 230.0 ± 105.0 mg/dL; P = 0.20). Untreated T2DM patients had non-significant FSG readings for the two samples (194.0 ± 151.5 mg/dL versus 193.9 ± 128.9 mg/dL; P = 0.90). Patients on insulin and OAD showed a similar pattern of FSG (268.0 ± 111.0 mg/dL versus 269.0 ± 114.0 mg/dL). However, the two FSG samples were found to be significantly different among patients on OAD (220.0 ± 78.0 mg/dL versus 207.0 ± 77.0 mg/dL; P = 0.01). Conclusion: The fasting duration of five to six hours can give a comparable measurement of FSG as that obtained after eight hours.

Vitamin D Metabolic Profiles in Premenopausal Women Wearing Niqab and Hijab in Sunny Basrah.

Background Conservative clothing like niqab and hijab may affect the wearer's vitamin D metabolic parameters even in predominantly sunny areas of the world (i.e., areas with adequate sunlight exposure throughout the year). Our objective was to evaluate the effect of wearing the niqab or hijab on different vitamin D3 metabolic parameters in a sample of premenopausal women from Basrah. Methodology This was a cross-sectional observational study on premenopausal women who wore a niqab (n = 64), with a comparable age-matched group of women who wore the hijab (n = 60). Biochemical evaluation of the vitamin D3 metabolic profile involved 25-hydroxycholecalciferol (25-OH)-vitamin D, corrected serum calcium, parathyroid hormone (PTH), phosphorus, and alkaline phosphatase estimation. Statistical comparison of these parameters was made using the independent sample t-test and Mann-Whitney-U test. Results The two groups of women were age- and weight-matched, with a median age of 39 and median body mass index (BMI) of 31.8 kg/m2. Overall, age, marital status, and BMI of women in both groups had no significant relationship with the vitamin D3 metabolic parameters (low 25-OH-vitamin D, low corrected calcium, and high PTH). The subgroup analysis for women wearing the niqab showed the same results. Conclusions Wearing niqab or hijab in premenopausal women was not associated with any significant statistical relationship or difference in vitamin D3 metabolic parameters. Conservative dress styles like niqab and hijab are practical barriers to sun exposure and contribute to suboptimal vitamin D levels, affecting subsequent metabolic pathways. Healthcare professionals should advise women who wear niqab or hijab to increase their vitamin D3 levels through culturally appropriate alternative mechanisms.

Prevalence and correlation of glycemic control achievement in patients with type 2 diabetes in Iraq: A retrospective analysis of a tertiary care database over a 9-year period.

BACKGROUND: This study was designed to assess the achievement of a glycated hemoglobin (HbA1c) target in Iraqi type 2 diabetes mellitus (T2DM) patients via retrospective analysis of a tertiary care database over a 9-year period. METHODS: A total of 12,869 patients with T2DM with mean (SEM) age: 51.4(0.1) years, and 54.4% were females registered into Faiha Specialized Diabetes, Endocrine and Metabolism Center(FDEMC) database between August 2008 and July 2017 were included in this retrospective study. Data were recorded for each patient during routine follow-up visits performed at the center every 3-12 months. RESULTS: Patients were under oral antidiabetic drugs (OAD; 45.8%) or insulin+ OAD (54.2%) therapy. Hypertension was evident in 42.0% of patients, while dyslipidemia was noted in 70.5%. Glycemic control (HbA1c <7%) was achieved by 13.8% of patients. Multivariate analysis revealed <55 years of age, female gender, >3 years duration of diabetes, HbA1c >10% at the first visit, presence of dyslipidemia, and insulin treatment as significant determinants of an increased risk of poor glycemic control. BMI <25 kg/m2 and presence of hypertension were associated with a decreased risk of poor glycemic control. CONCLUSION: Using data from the largest cohort of T2DM patients from Iraq to date, this tertiary care database analysis over a 9-year period indicated poor glycemic control. Younger patient age, female gender, longer disease duration, initially high HbA1c levels, dyslipidemia, insulin treatment, overweight and obesity, and lack of hypertension were associated with an increased risk of poor glycemic control in Iraqi T2DM patients.

Terapias emergentes: inhibidores de glicoproteína IIB/IIIA en ataque cerebrovascular agudo: [revisión] / Emergent therapies: platelet glycoprotein IIb/IIIa inhibitors in acute ischemic stroke: [review]

El ataque cerebrovascular (ACV) es una causa común de morbilidad y mortalidad en el mundo. La terapia trombolítica con (r-TPA), es la única terapia aprobada para el tratamiento del ACV y esta terapia solo se logra aplicar en el 2% de los pacientes. Se necesitan nuevas modalidades terapéuticas en ACV que puedan usarse en un periodo entre 4,5 a 6 horas después de iniciados los síntomas y con menores complicaciones hemorrágicas, que las que se presentan con la terapia trombolítica. Los inhibidores de glicoproteinas IIb/IIIa (IG), producen una rápida y efectiva inhibición de la agregación plaquetaria ayudando a preservar la microvasculatura y han demostrado propiedades neuroprotectoras. Los receptores de glicoproteina IIb/IIIa son los mas abundantes en las plaquetas y es sobre ellos que actúan los IG, dentro de los cuales cabe mencionar el abciximab, el tirofiban, y el eptifibatide. Los IG, después de su éxito inicial en pacientes con síndromes coronarios agudos, se convirtieron en terapias prometedoras en pacientes con ACV, sin embargo el periodo de ventana, el tipo de ACV, el riesgo de hemorragia sintomática y asintomática no están claros en el momento. Esta revisión se enfoca en el uso de IG en ACV. Elabciximab ha mostrado ser seguro y efectivo en series de casos y en algunos estudios, si embargo no ha mejorado el desenlace de los pacientes con ACV y esta asociado a una mayor tasa de sangrado. El tirofiban perece ser más seguro y efectivo en estudios iniciales, sin embargo se necesitan más ensayos para establecer su papel en ACV.

Acute ischemic stroke (AIS) is a common cause of morbidity and mortality worldwide. Thrombolytic therapy with tissue plasminogen activator, the only approved treatment for AIS, is received by less than 2% of patients. Moreover, there is a slight increase in hemorrhagic complications with thrombolysis. Therefore, there is a need for newer therapeutic modalities in AIS, which could be used in window periods beyond 4.5-6 h after stroke onset with fewer hemorrhagic complications. Platelets Glycoprotein IIb/IIIa (PGI) induces a rapid and effective inhibition of platelet aggregation. GPIs have been reported to preserve microvascular patency in animal stroke studies and may have neuroprotective properties. The platelet glycoprotein GP IIb/IIIa, which is the most abundant platelet receptor, also represents the drug target of a novel class of anti-platelet drugs, which includes abciximab, tirofiban, and eptifibatide. The GPI, after their initial success in patients with acute coronary syndromes, promised much in patients with AIS, including the window periods and type of strokes, and the risk of symptomatic or asymptomatic hemorrhage are unclear at the moment. The current review focuses on the literature concerning the use of GPI in AIS and looks at the available evidence regarding their use. Abciximab thought to be safe and effective in initial case series and early trials, has not been shown to improve outcomes in AIS, and is associated with higher rates of hemorrhage. Tirofiban appears to be safe and effective in initial trials and there is a need to conduct further trials to establish its role in AIS.

The alpha-defensins stimulate proteoglycan-dependent catabolism of low-density lipoprotein by vascular cells: a new class of inflammatory apolipoprotein and a possible contributor to atherogenesis.

Inflammation may contribute to the pathogenesis of atherosclerosis. On the basis of previous reports that human atherosclerotic lesions contain alpha-defensins, a class of cationic proteins released by activated neutrophils, the study was designed to ask whether defensins modulate the binding and catabolism of low-density lipoprotein (LDL) by human vascular cells. The results of the study demonstrated that defensin stimulated the binding of (125)I-LDL to cultured human umbilical vein endothelial cells, smooth muscle cells, and fibroblasts approximately 5-fold in a dose-dependent and saturable manner. Defensin and LDL formed stable complexes in solution and on cell surfaces. Stimulation of LDL binding by defensin was not inhibited by antibodies against the LDL-receptor (LDL-R), or by recombinant receptor-associated protein, which blocks binding of ligands to the alpha(2)-macroglobulin receptor/LDL-R-related protein and other LDL-R family members. Furthermore, defensin stimulated the binding, endocytosis, and degradation of LDL by fibroblasts lacking LDL-R. Stimulation of LDL degradation by defensin was inhibited approximately 75% by low concentrations of heparin (0.2 units/mL) and was similarly reduced in CHO cells lacking heparan-sulfate-containing proteoglycans. The effect of defensin was substantially increased in cells overexpressing the core protein of the syndecan-1 heparan sulfate proteoglycan. The alpha-defensins released from activated neutrophils may provide a link between inflammation and atherosclerosis by changing the pattern of LDL catabolism from LDL-R to the less efficient LDL-R-independent, proteoglycan-dependent pathway. (Blood. 2000;96:1393-1398)

Urokinase-derived peptides regulate vascular smooth muscle contraction in vitro and in vivo.

We examined the effect of urokinase (uPA) and its fragments on vascular smooth muscle cell contraction. Single-chain uPA inhibits phenylepherine (PE) -induced contraction of rat aortic rings, whereas two-chain uPA exerts the opposite effect. Two independent epitopes mediating these opposing activities were identified. A6, a capped peptide corresponding to amino acids 136-143 (KPSSPPEE) of uPA, increased the EC(50) of PE-induced vascular contraction sevenfold by inhibiting the release of calcium from intracellular stores. A6 activity was abolished by deleting the carboxyl-terminal Glu or by mutating the Ser corresponding to position 138 in uPA to Glu. A single-chain uPA variant lacking amino acids 136-143 did not induce vasorelaxation. A second epitope within the kringle of uPA potentiated PE-induced vasoconstriction. This epitope was exposed when single-chain uPA was converted to a two-chain molecule by plasmin. The isolated uPA kringle augmented vasoconstriction, whereas uPA variant lacking the kringle had no procontractile activity. These studies reveal previously undescribed vasoactive domains within urokinase and its naturally derived fragments.

Novel interactions between urokinase and its receptor.

Urokinase-type plasminogen activator (uPA) binds to its receptor (uPAR) with a K(d) of about 1 nm. The catalytic activity of the complex is apparent at uPA concentrations close to K(d). Other functions of the complex, such as signal transduction, are apparent at much higher concentrations (35-60 nm). In the present study, we show that uPA and recombinant soluble uPAR (suPAR), at concentrations that exceed the K(d) and the theoretical saturation levels (10-80 nm), establish novel interactions that lead to a further increase in the activity of the single-chain uPA (scuPA)/suPAR and two-chain uPA (tcuPA)/suPAR complexes. Experiments performed using dynamic light scattering, gel filtration, and electron microscopy techniques indicate that suPAR forms dimers and oligomers. The three techniques provide evidence that the addition of an equimolar concentration of scuPA leads to the dissociation of these dimers and oligomers. Biacore data show that suPAR dimers and oligomers bind scuPA with decreased affinity when compared with monomers. We postulate that uPAR is present in equilibrium between oligomer/dimer/monomer forms. The binding of uPA to suPAR dimers and oligomers occurs with lower affinity than the binding to monomer. These novel interactions regulate the activity of the resultant complexes and may be involved in uPA/uPAR mediated signal transduction.

Determination of lipoic acid and dihydrolipoic acid in human plasma and urine by high-performance liquid chromatography with fluorimetric detection.

A highly sensitive method for the determination of alpha-lipoic acid (LA) and dihydrolipoic acid (DHLA) in human plasma and urine has been developed. Samples were acidified and extracted with organic solvent, and the free sulfhydryls of DHLA protected as the dicarboxyethylate by treatment with ethylchloroformate. The free carboxylic function of LA and the SH-protected DHLA were converted into their amide derivatives with the strong fluorophore 2-(4-aminophenyl)-6-methylbenzothiazole in the presence of a coupling agent and a base catalyst. The resulting fluorescent amides of both LA and DHLA were separated on a reversed-phase column (Ultrasphere C8) using simple isocratic elution with acetonitrile-water (80:20) and detected fluorimetrically (excitation 343, emission 423 nm). The method is highly sensitive, reproducible, and is easily applied for the simultaneous determination of LA and DHLA in biological samples.

Representative Salmonella serovars isolated from poultry and poultry environments in Saudi Arabia.

The authors describe the source and prevalence of pathogenic Salmonella serovars among poultry farms in Saudi Arabia. A total of 1,052 (4%) Salmonella isolates were recovered from 25,759 samples of poultry (broilers, layers, broiler breeders and layer breeders) and poultry environments (box liner, litter, drag swab, droppings, mice and feed) were examined bacteriologically between 1988 and 1997 at the Poultry Disease Laboratory at the National Agriculture and Water Research Center in Riyadh. Eleven Salmonella serogroups representing 38 different Salmonella serovars were identified by means of antigenic analysis. The majority of the 276 isolates (26.2%) of Salmonella typed, were recovered from liver, heart and intestines of the broilers and layers. The most prominent Salmonella serogroups isolated were as follows: serogroup C1 (392 isolates, 37.26%), B (289 isolates, 27.47%) and D1 (269 isolates, 25.69%). However, untypable and multiple serogroups were also encountered, the most frequent isolates serotyped belonged to groups C1 (97 isolates, 24.7%), D1 (86 isolates, 31.9%), and B (71 isolates, 24.6%). Salmonella Enteritidis (85 isolates, 98.8%), Salmonella Virchow (48 isolates, 57.8%), Salmonella Paratyphi B var. Java (41 isolates, 57.7%) and Salmonella Infantis (30 isolates, 20.6%) were distributed the most widely as all were encountered in poultry and in poultry environments. S. Enteritidis phage type 4 (30 isolates, 35.3%), was the phage type most frequently detected among group D1 phage types, while 39 (45.8%) of the isolates of S. Enteritidis could not be phage typed.

Effects of the superoxide dismutase-mimic compound TEMPOL on oxidant stress-mediated endothelial dysfunction.

The aim of this study was to investigate the effects of oxidant stress on endothelium-dependent and endothelium-independent arterial relaxation. For this, oxidant stress was generated by preincubation of rat aortic rings (RARs) in either 25 mM glucose (mimicking hyperglycemic stress) or 0.5 mM pyrogallol (a superoxide generator) and the effects of the superoxide dismutase (SOD)-mimetic compound 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy free radical (TEMPOL) on the vasorelaxant and cGMP-producing effects of acetylcholine (ACh) and glyceryl trinitrate (GTN) in control RARs and RARs exposed to oxidant stress were examined. Pyrogallol, and to a lesser extent high glucose concentration, enhanced the contractile response of RARs to phenylephrine and markedly inhibited the vasorelaxant response to ACh. Although they existed, the inhibitory effects of high glucose and pyrogallol on the vasorelaxant response to GTN were less profound, especially with pyrogallol. Moreover, both pyrogallol and high glucose concentration inhibited the basal and the ACh-induced vascular cyclic guanosine monophosphate (cGMP) production. Treatment with TEMPOL (1-5 mM) slightly increased the ACh and GTN-induced cGMP levels in control RARs but had a significant effect in high glucose and pyrogallol-pretreated RARs. Additionally, concomitant treatment of RARs with TEMPOL (5 mM) abolished the difference in the relaxation response between control RARs and RARs exposed to either pyrogallol or high glucose concentration. These results further support the theory that reactive oxygen species (ROS), especially superoxide, play a key role in mediation of endothelial dysfunction accompanying diabetes, probably through their effects on the ability of the endothelium to synthesize, release or respond to endogenous nitric oxide (NO) or NO donated by nitrovasodilators.

Decontamination of chicken carcasses artificially contaminated with Salmonella.

A study was conducted to evaluate the efficacy of three chemical disinfectants and of ionising radiation in reducing the level of contamination in chicken carcasses which had been artificially contaminated with Salmonella Virchow. Chicken carcasses were obtained from a local abattoir. Five carcasses and one control carcass were used to test each concentration of disinfectant and the radiation. The amount of contaminant employed was 0.5 ml of 10(4) colony-forming units per ml of S. Virchow spread over the thigh, breast and wing areas. All treatments were conducted in duplicate. The three disinfectants used were as follows: calcium hypochlorite, at concentrations of 20 ppm, 50 ppm, 100 ppm and 200 ppm of available chlorine. Lactic acid at concentrations of 0.5%, 0.75% and 1%. Hydrogen peroxide compound at concentrations of 1%, 2% and 3%. Five inoculated carcasses were immersed at a time in one disinfectant concentration for 15 min, while the control carcasses were simultaneously immersed in water free from disinfectants. Five carcasses, each in a plastic bag, were subjected to varying ascending doses (from 2 to 7 k gray [kGy]) of ionising radiation from radioactive isotopes of cobalt 60. A bacteriological examination of each carcass was conducted after the treatment to determine the presence or absence of S. Virchow. The number of carcasses which gave positive results showing the presence of Salmonella decreased after chemical treatment, but the organism was not completely eliminated. However, in those carcasses subjected to 7 kGy of radiation, Salmonella was eliminated and no changes in the appearance, colour or smell of the carcasses were observed.

Use of live and inactivated Salmonella enteritidis phage type 4 vaccines to immunise laying hens against experimental infection.

Four groups of Dekalb Delta commercial layer hens (8 hens per group) were reared individually in cages in an isolation unit. At the age of 8 weeks, groups 1 and 2 were vaccinated with 9R Salmonella gallinarum live (9R live) vaccine. At the age of 18 weeks, group 1 was re-vaccinated with 9R live S. enteritidis vaccine, while groups 2 and 3 were vaccinated with S. enteritidis bacterin. At the age of 22 weeks, groups 2 and 3 were re-vaccinated with S. enteritidis bacterin. Group 4 was not vaccinated and was kept as a control group. At 24, 27 and 30 weeks of age, the four groups were challenged using various concentrations of S. enteritidis phage type 4 and various routes of inoculation. Eggs, cloacal swabs and blood were collected weekly for bacteriological and serological examination. Isolation of the challenge organism from the eggshells and egg contents of the vaccinated groups was significantly lower than with the control group. There was no correlation between humoral antibodies and the shedding of the challenge organism in eggs or cloacal swabs. A combined vaccination programme of 9R live S. enteritidis vaccine and S. enteritidis bacterin provided better protection to laying hens than either vaccine administered alone. Vaccination should never be performed alone but in conjunction with other measures related to veterinary hygiene and good management.

Massive edema of the ovary. A case report and a review of the literature.

A patient with massive ovarian edema is described. This represents the eighth such case in the literature and the largest tumor reported. The literature on massive ovarian edema is reviewed and summarized.

The combined influence of age of embryo and temperature and duration of incubation on the replication and yield of avian infectious bronchitis (IB) virus in the developing chick embryo.

Two experiments were undertaken to investigate the combined influence of the age of embryo at infection and the temperature and duration of incubation on the replication and yield of the Beaudette strain of IB virus lin allantoic fluid and the chorio allantoic membrane. In general a higher titre of virus was found in the allantoic fluid and chorioallantoic membrane of living embryos than of dead ones and with continued incubation of dead embryos the titre of virus fell still further. For embryos of the same age at infection peak titres were similar for those incubated at 32 degrees C and 37 degrees C but were greater than for the corresponding embryos at 42 degrees C. The range of titres for embryos of all ages associated with duration of incubation was narrower for those incubated at 32 degrees C than at 37 degrees C and 42 degrees C and a longer survival period was observed for embryos incubated at 32 degrees C. Peak titres of virus for all age groups were observed after 24 h at 32 degrees C and after 12 h at 37 degrees C and 42 degrees C and then declined. The highest titre for virus in allantoic fluid, in both experiments, was in the 10 d old embryos at 32 degrees C harvested after 24 h. For the chorioallantoic membrane the highest titre in the first experiment was in 12 d old embryos at 32 degrees C, harvested after 24 h, while in the second it was also in 12 d old embryos but at 37 degrees C and harvested after 12 h. The lowest titre of all was in 10 d old embryos incubated at 42 degrees C. It is considered that the maximum total yield of virus from the allantoic fluid and chorio allantoic membrane of the same embryo will be in those infected at 10 - 12 d of age incubated at 32 degrees C to 37 degrees C.