Biochemical and physiological validation of a corticosteroid radioimmunoassay for plasma and fecal samples in oldfield mice (Peromyscus polionotus)

The measurement of fecal steroids provides an increasingly important noninvasive technique for assessing reproduction, environmental stress, and aggression in populations of captive and free-living animals. In this paper, we validated the corticosterone (CORT) 125I-radioimmunoassay (ICN Pharmaceuticals) for plasma and fecal samples in a small rodent species, the oldfield mouse (Peromyscus polionotus subgriseus). The biochemical validations indicated that the assays accurately measured CORT concentrations in the plasma and corticosteroid concentrations in the feces. Physiological validation demonstrated that: (1) blood samples collected within 3 min of disturbing an animal's cage represented "baseline" CORT concentrations, and (2) fecal corticosteroid concentrations collected over a 24-h period closely tracked plasma CORT concentrations approximately 4 h earlier. These results demonstrate that the plasma CORT and fecal corticosteroid assays are sensitive enough to detect biologically meaningful alterations in corticosteroid concentrations in oldfield mice.

Pathological Effects of Formalin (37% Formaldehyde) Mixed in Feed or Administered into the Crops of White Leghorn Cockerels

This study compared the adverse effects of formalin administered by two different methods. Formalin mixed with the feed (2.5, 5.0 and 10 ml/kg) was given to 10-week-old White Leghorn cockerels for a period of 8 weeks. Simultaneously in other groups, a 3% solution of formalin was administered into the crops (5, 10, 15 and 20 ml/bird/day). Total amount of formalin utilized during the experiment in the feed of individual bird of groups given 2.5, 5 and 10 ml/kg was 6.25, 3.9 and 1.6% higher than those administered 5, 10 and 20 ml of 3% formalin into crop, respectively. Body mass and feed intake in all feed-mixed groups and those given 5 and 10 ml formalin (3%) into the crop were not significantly different from control. Administration of 15 and 20 ml formalin (3%) into crop resulted in depression, delayed onset of crowing, significantly decreased feed intake, lower body mass, decreased mass and volume of testes, ulceration in crops, sloughing of mucosa and petechial haemorrhages in proventriculus. All the groups given formalin had significantly smaller diameters of seminiferous tubules. Kidneys of the birds administered formalin into crop exhibited pyknotic nuclei of epithelial cells in proximal tubules. Non-significant differences in different parameters and lesser degree of pathological changes in birds given formalin-mixed feed than their corresponding crop-administered groups suggested that formalin present in the feed had partially evaporated. Therefore, birds ingested less amount of formalin than that originally mixed in the feed.

Concentrations of four fecal steroids in wild baboons: short-term storage conditions and consequences for data interpretation

One source of both bias and "noise" in fecal steroid analysis is temporal change in steroid concentrations resulting from duration or conditions of fecal sample storage. However, no consensus currently exists regarding correct procedures or precautions necessary for fecal sample storage, and conditions vary widely within field endocrinology literature. This study considered the effects of short-term, weeks-long, storage conditions on quantifiable fecal testosterone (fT), glucocorticoids (fGC), estrogens (fE), and progestagen (fP) metabolite concentrations in wild baboons (Papio cynocephalus). Quadruplicate subsamples of fecal samples (n=29) collected at Amboseli National Park and its environs were subjected to four different storage conditions prior to lyophilization, in order to determine the effects of storage on subsequent steroid concentrations, as assessed by 125I radioimmunoassays. As expected, the best alternative to the "initial condition" of lyophilization at three days after collection was to freeze fecal samples at -20 degrees C for two weeks prior to lyophilization. This storage method resulted in no significant change from initial steroid concentrations for fE, fT, or fP, although fGC showed a slight but significant decline. Storage for two weeks in a charcoal refrigerator caused a mean increase in all four steroid concentrations. However, the results from this storage condition were robust in terms of practical questions asked of the data: fE and fP values still reflected pregnant versus non-pregnant states in baboon females; a fGC profile constructed by age class resembled that created from the samples from the initial condition, although slightly inflated across age classes; and there were only moderate changes in relative fT concentrations across adult males. Knowledge of the effects of storage upon each steroid analyzed within one's study is a necessary component in determining the optimal compromise for storage protocol in a particular research project.

A matter of time: evaluating the storage of fecal samples for steroid analysis

The extraction and immunoassay of fecal steroids is an increasingly common technique, used in both captive and field studies to provide an approximation of an animal's circulating concentration of hormones through non-invasive methods. Storage of fecal samples is of critical concern because fecal bacteria metabolize fecal steroids within hours after deposit. Ethanol is often used as a preservative for fecal samples stored for several hours at room temperature. We examined the stability of fecal estrogen (fE) and glucocorticoid (fGC) metabolites from baboon (Papio cynocephalus) samples in a 95% ethanol solution at ambient temperature and at -20 degrees C over the course of six months, to determine the effect of storage on steroid concentrations. As measured by radioimmunoassay, fE metabolite concentrations increased by 122% at 90 days and fGC metabolite concentrations increased by 92% at 120 days. After peaking, both hormones declined to near initial concentrations by 180 days in ambient temperature samples. In samples stored at sub-zero temperatures, fGC metabolite concentrations showed a similar but dampened pattern, while fE metabolite concentrations exhibited small and variable changes with no consistent trend. We discuss explanations for the dynamic pattern of changing fecal metabolite concentrations and offer practical and analytical guidance to field workers for situations in which ideal conditions for stabilizing hormones are not available.

Effects of dietary formalin on the health and testicular pathology of male Japanese quails (Coturnix coturnix Japonica)

Male Japanese quail (n = 75) at 35 d of age were fed 20.0, 10.0, 5.0, 2.5 or 0 ml formalin (37% formaldehyde)/kg of their daily ration for 8 w. Quail fed 20.0 or 10.0 ml formalin/kg feed showed depression, decreased responsiveness, feed consumption, and body weights, and had vacuolation in the germinal epithelial layer of their seminiferous tubules. Formalin feeding at up to 5 ml/kg was associated with decreased weight of testes, and up to 2.5 ml/kg feed resulted in smaller diameter seminiferous tubules.

Thermal behaviour of diclofenac sodium: decomposition and melting characteristics

The thermal behaviour and melting characteristics of diclofenac sodium were investigated using various instrumental techniques--differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy and thin layer chromatography (TLC). DSC analysis of diclofenac sodium performed under dynamic flow of either synthetic air or helium or nitrogen did not produce any sharp endothermic peak characteristic of melting peak of a pure substance. Both the rate of scanning of the sample and the environmental atmospheric condition significantly affected the thermographic profile of diclofenac sodium. An exothermic peak prior to an endothermic peak corresponding to melting of the substance appeared when heated under dynamic flow of synthetic air suggesting oxidation (decomposition) of diclofenac sodium before reaching its melting point. In fact, at a scanning rate of 1 degree C/min only the exothermic peak appeared in the thermogram, suggesting complete decomposition prior to melting under the dynamic flow of synthetic air. DSC, FT-IR and TLC data obtained from samples heated under the dynamic flow of either helium or nitrogen revealed formation of a related compound, 1-(2,6-dichlorophenyl)-indolin-2-one, an indol-cyclic amide, as a result of an intramolecular cyclization reaction during the heating process. TGA data demonstrated a loss of 11.4-20.2% of the mass of diclofenac sodium when heated under various environmental conditions, and also supported the oxidative nature of degraded product(s) when the thermal process occurred slowly under a dynamic flow of synthetic air.

Prevalence of mental health problems in acne patients

BACKGROUND

Acne is the most common of all skin diseases. The condition affects young people at the time when they are undergoing maximum social and physical change and can produce significant psychological scarring. This study was done to determine the Mental Health problem in Patients suffering from acne and to determine significant difference of mental health problems in acne patients in comparison to seborrhic dermatitis patients as a control group.

METHODS

50 subjects with acne and 50 with seborrhic skin problems (13-25 yrs age) were included in this study through Psychiatry OPD of Lady Reading Hospital, Peshawar. The period of study was from March 1998 to August 1998. The patients were assessed for psychiatric problems by using WHO Guide to mental health in primary care ICD 10 chapter V primary care. The statistical significance was determined by chi square.

RESULTS

The data shows that out of 50 acne patients 19 (38%) were suffering from Depression, with a female predominance. The control group (seborrhic) presented lower prevalence of Depression i.e. 57% in females. Similarly Anxiety problem in particular social anxiety were overall more in acne group (34%) as compared to seborrhea group (10%). A statistically significant difference was observed between the two groups indicating that depression and social anxiety was more in the acne group. A consistent finding in the study over six months depicted the difference between gender i.e. more females presenting with depression. Total Depressed Patients were 19, while total with suicidal Thoughts were 4 (21%).

CONCLUSION

The importance of this study is to highlight depression among such patients.

Patterns of testosterone and prolactin concentrations and reproductive behavior of helpers and breeders in the cooperatively breeding red-cockaded woodpecker (Picoides borealis)

We examined the proximate causes of delayed breeding and alloparental behavior in the cooperatively breeding red-cockaded woodpecker by measuring plasma concentrations of testosterone (T) and prolactin (PRL) in female breeders, male breeders, and male helpers during different stages of the reproductive cycle. Male breeders and helpers have low T during the prebreeding period, highest T during copulation, and low concentrations of T during the egg-laying/incubation and nestling provisioning stages. Helpers appear physiologically capable of reproducing; their T concentrations equal that of male breeders. Helpers unrelated to the breeding female have higher T than helpers sharing a territory with their mother. Sexual inactivity by male helpers might be explained by behavioral suppression resulting from interactions of male helpers with the breeding pair that somehow differ in accordance with the helper's relatedness to the breeding female (e.g., female breeders are generally unreceptive to courtship from male helpers and least receptive to related helpers). Female breeder, male breeder, and male helper PRL levels did not differ and increased from the prebreeding stage through the copulation and egg-laying/incubation stages. During the nestling provisioning stage, male breeder and helper PRL declined, while female PRL continued to increase. Based on these results, we conclude that the physiological bases of alloparental behavior have not diverged from those that mediate parental behavior in this species.

Diagnosis of deep vein thrombosis in the leg by using colour coded duplex sonography

BACKGROUND

Deep Vein Thrombosis (DVT) is regarded rare [not readable: see text] Asia. There is no documentation of the incidence of DVT in Pakistan. Clinical diagnosis of Deep Vein Thrombosis is inaccurate. Venography is the most reliable method of diagnosis, but it has several disadvantages. Many non-invasive diagnostic methods have therefore been developed in the past decade. Of these only duplex sonography has comparable accuracy.

METHODS

We studied 100 cases of suspected DVT by using colour coded duplex sonography. We report the results of a prospective study in patients with suspected deep vein thrombosis evaluated by both colour coded Doppler sonography and venography.

CONCLUSION

We conclude that colour coded duplex sonography is a highly accurate, simple, non-invasive method for detecting femoropopliteal thrombosis. Additional venography is not necessary. Its value in diagnosing isolated calf vein thrombosis remains to be established.

Large granular lymphocytes in the oviduct of developing and hormone-treated chickens

1. In the present study the distribution of large granular lymphocytes (LGLs) and influence of oestrogen on these cells was investigated in the oviduct of chickens by the observation of H and E stained sections. 2. The LGLs first appeared in the oviduct at 9 weeks and their frequency of occurrence increased with age and was highest in the infundibulum and vagina from 21 to 32 weeks of age. The frequency of occurrence of LGLs from magnum to uterus (glandular part) was low. These cells were located at the base, middle and apical parts of the lining epithelium as well as in the sperm-storage glandular epithelium. 3. When chickens of 21 weeks were treated with DES, LGLs abundantly infiltrated in the oviducal epithelium in comparison to the control. 4. These results suggested that the development of LGLs in the oviduct of chickens correlates with oestrogen secretion.

An unusual cause of femoral embolism: angioseal

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A pH-dependent colon-targeted oral drug delivery system using methacrylic acid copolymers. II. Manipulation of drug release using Eudragit L100 and Eudragit S100 combinations

Tablets containing mesalazine as a model drug were coated using various combinations of two methacrylic acid copolymers, (Eudragit L100 and Eudragit S100) by spraying from aqueous systems. The Eudragit L100-Eudragit S100 (w/w) combinations studied were 1:0, 4:1, 3:2, 1:1, 2:3, 1:4, 1:5, and 0:1. The coated tablets were tested in vitro for their suitability for pH-dependent colon-targeted oral drug delivery. The dissolution profiles of the drug obtained from the studied tablets demonstrate that the release of the drug could be manipulated by changing the Eudragit L100-Eudragit S100 ratios in the combinations within the pH range between 6.0 and 7.0 in which the individual polymers are soluble, and a coating formulation consisting of a combination of the two polymers can overcome the issue of high gastrointestinal (GI) pH variability among individuals. The results also demonstrate the feasibility of using aqueous dispersions of Eudragit L100-Eudragit S100 combinations for coating tablets for colon-targeted delivery of drugs, and that the formulation can be adjusted to deliver drug(s) at any other desirable site of the intestinal region of the GI tract in which pH of the fluid is within the range 6.0 to 7.0. For colon-targeted delivery of drugs, the proposed combination system is superior to tablets coated with either Eudragit L100 or Eudragit S100 alone.

Relation of preoperative sialographic findings with histopathological diagnosis in cases of obstructive sialadenitis of the parotid and submandibular glands: retrospective study

The clinical records, preoperative sialograms and histopathological slides of 33 patients who had been operated on for symptoms of obstructive salivary gland disease were reviewed. Twenty patients had had superficial parotidectomy and 13 excision of the submandibular gland. Among those who had required parotidectomy, preoperative sialograms tended to suggest more architectural damage than was actually noted on definitive histopathological examination. Patients whose symptoms had been present for longer had more severe sialographic and histopathological changes. In the submandibular group, there was a closer relation between sialographic and histopathological changes, and a positive correlation between a short history and the severity of histopathological grading. These differences may reflect the different aetiology and course of obstructive disease in the two types of gland.

A pH-dependent colon targeted oral drug delivery system using methacrylic acid copolymers. I. Manipulation Of drug release using Eudragit L100-55 and Eudragit S100 combinations

Lactose-based placebo tablets were coated using various combinations of two methacrylic acid copolymers, Eudragit L100-55 and Eudragit S100, by spraying from aqueous systems. The Eudragit L100-55-Eudragit S100 combinations (w/w) studied were 1:0, 4:1, 3:2, 1:1, 2:3, 1:4, 1:5 and 0:1. The coated tablets were tested in vitro for their suitability for pH dependent colon targeted oral drug delivery. The same coating formulations were then applied on tablets containing mesalazine as a model drug and evaluated for in vitro dissolution rates under various conditions. The disintegration data obtained from the placebo tablets demonstrate that disintegration rate of the studied tablets is dependent on: (i) the polymer combination used to coat the tablets, (ii) pH of the disintegration media, and (iii) the coating level of the tablets. Dissolution studies performed on the mesalazine tablets further confirmed that the release profiles of the drug could be manipulated by changing the Eudragit L100-55 and Eudragit S100 ratios within the pH range of 5.5 to 7.0 in which the individual polymers are soluble respectively, and a coating formulation consisting of a combination of the two copolymers can overcome the issue of high gastrointestinal (GI) pH variability among individuals. The results also demonstrated that a combination of Eudragit L100-55 and Eudragit S100 can be successfully used from aqueous system to coat tablets for colon targeted delivery of drugs and the formulation can be adjusted to deliver drug at any other desirable site of the intestinal region of the GI tract on the basis of pH-variability. For colon targeted delivery of drugs the proposed combination system is superior to tablets coated with either Eudragit L100-55 or Eudragit S100 alone.

Paracetamol-propyphenazone interaction and formulation difficulties associated with eutectic formation in combination solid dosage forms

Polymorphic behaviours of paracetamol and propyphenazone and interaction between these two compounds were investigated using differential scanning calorimetry (DSC), X-ray powder diffraction and Fourier transform-infrared (FT-IR)-spectroscopy. Binary mixtures containing various ratios of the compounds were prepared as physical and fused mixtures and analysed by DSC to study their thermal behaviours. Phase diagrams obtained from the melting endotherms of the binary mixtures demonstrated formation of an eutectic mixture at a paracetamol-propyphenazone combination of about 35:65 (w/w) with an eutectic temperature of 56 degrees C. The FT-IR spectroscopy revealed no chemical interaction due to eutectic formation, and a lower degree of crystallinity of the eutectic mixture than individual substances was observed by X-ray powder diffraction analysis. The DSC and X-ray powder diffraction data demonstrated a polymorphic change in propyphenazone as a result of melting of the compound. Tablets, containing both paracetamol and propyphenazone in a combination formulation and prepared using standard wet granulation technology, were found to have physical instability when packed in either polyvinylchloride// aluminium or polyvinylchloride/polyvinyldienechloride// aluminium blisters and stored for one month at 40 degrees C with either 75% relative humidity or without any humidity control. The instability of the tablets was more apparent under the high humidity condition.

Macrophages in the chicken oviduct: morphometrical studies by light and transmission electron microscopy and the possible influence of sex hormones

Light and electron microscopic techniques were used to study the morphometry and dynamic changes of macrophages in the postnatal and sex hormone-treated chicken oviduct, respectively. Abundant typical macrophages, containing clear vacuoles, well-developed mitochondria, Golgi complexes and lysosomal bodies in their cytoplasms, were observed in the lamina propria of all segments of the postnatal chicken oviduct, occurring more frequently in the vaginal part. When 7-day-old chickens were injected with diethylstilbestrol (DES), and DES plus progesterone, infiltration of a significant number of macrophages in both groups, but not in controls could be seen. The light and electron microscopic structures of the macrophages in both postnatal and sex hormone-treated chicken oviduct were similar. These results show that typical macrophages are present in the chicken oviduct; their frequency of occurrence varies with different oviductal segments, and they are influenced by sex hormones.

Furazolidone toxicosis in female Japanese quail (Coturnix coturnix japonica): pathomorphological changes in reproductive tract and reversibility of the induced changes

Female Japanese quail (Coturnix coturnix Japonica) placed in 3 equal groups were given 600, 400 or 0 mg furazolidone (Fz)/kg feed for 4 w and then withdrawn for another 4 w. Another (pair-fed) group of same size was given basal feed as much as was consumed by the quail fed 600 mg Fz/kg feed. Fz feeding decreased body weight, feed intake and egg production. Ovaries of the Fz-fed quail decreased in weight and size and were studded with small follicles. Magnum, isthmus and uterus in Fz-fed groups had decreased area, height and number of mucosal folds compared with the control group. Microscopically, in Fz-fed groups, the mucosal glands in magnum and isthmus had decreased cell height with centrally located nuclei and foamy cytoplasm. In the 600 mg Fz-fed group, some birds had atrophy of the glandular tissue in the mucosa and infiltration of mononuclear cells and fibroblasts. Upon cessation of the Fz feeding, all parameters reversed gradually and became non-significantly different from control quail. These observations suggested that Fz-induced changes in mature female quail were reversible.

Hormonal profiles of callipyge and normal sheep

Five sheep expressing the callipyge gene, which causes muscle hypertrophy, were compared with five normal sheep to determine whether endocrine differences existed between genotypes. Blood samples were taken at 15-min intervals for 6 h to measure serum concentrations of growth hormone and insulin. Thyroxine and IGF-I levels were determined in single samples. No differences were found in mean serum growth hormone concentrations, growth hormone pulse amplitude, or pulse frequency (P > .3). Insulin concentrations were not different between genotypes before or after feeding (4.5 +/- 1.3 ng/mL callipyge vs 4.9 +/- 1.7 ng/mL normal, P > .4). The IGF-I concentrations did not differ (273.8 +/- 17.6 ng/mL callipyge vs 261.4 +/- 12.3 ng/mL normal). Serum thyroxine concentrations also were not different (5.9 +/- 2.3 microg/mL for callipyge vs 5.1 +/- 2.1 microg/mL normal, P > .3). In a separate experiment, five ewe lambs with and five without the callipyge gene were stressed to determine whether the adrenocortical response to stress differed between genotypes. Blood samples were taken at 15-min intervals for 2 h before, during, and after restraint stress. Restraint increased serum cortisol concentrations in both groups (P < .001), but genotypes did not differ at any time (P > .3). These results suggest that differences in muscling are not due to differences in systemic hormone secretion. The results of the second experiment indicate that callipyge and normal sheep have similar adrenocortical responses to stress.

A preliminary comparison of plasma fibrinogen concentrations, leukocyte numbers and erythrocyte sedimentation rate as non-specific indicators of inflammatory conditions in buffalo (Bubalis bubalis)

The plasma fibrinogen concentration (Fib), total leukocyte count (TLC), neutrophil, lymphocyte and monocyte numbers, and the erythrocyte sedimentation rate (ESR) were determined in 153 buffaloes suffering from different clinical conditions. Fib increased significantly (p < 0.05) in chronic mastitis, pyrexia, pyometra, cutaneous abscesses, tail gangrene and acute indigestion, whereas in most of the other conditions studied it varied non-significantly. TLC increased significantly in chronic mastitis, pyrexia, endometritis, cutaneous abscesses and infected skin wounds. An increase in neutrophils was associated with an increased TLC. Numbers of lymphocytes varied non-significantly in most of the conditions. Monocytes decreased significantly in most of the acute conditions. ESR was significantly elevated in all clinical conditions. Significantly increased mean Fib values in the different conditions varied from 703 +/- 119 to 725 +/- 140 mg/dl, while the maximum individual value was 1510 mg/dl in a case of cutaneous myiasis. The significantly increased mean TLC ranged from 9.48 +/- 2.91 to 11.1 +/- 3.5 x 10(3)/microliter, while it was 21.7 x 10(3)/microliter in a case of meningitis. ESR values in sick buffaloes varied from 57 to 111 mm in the first hour.

Postnatal development of B lymphocytes and immunoglobulin-containing plasma cells in the chicken oviduct: studies on cellular distribution and influence of sex hormones

Postnatal development of B lymphocytes and plasma cells containing different classes of immunoglobulins (IgG, IgA, and IgM) was immunohistochemically studied in the oviduct of the Dekalb strain of the White Leghorn chicken. B lymphocytes first appeared in the lamina propria of the chicken oviduct at 5 weeks of age. Their frequency of occurrence peaked at 15 weeks from the infundibulum to the uterus (glandular part), while in the vagina (aglandular part) it did so at 21 weeks. Intraepithelial B lymphocytes were very rare and exclusively located in the vagina at 19 and 21 weeks. Plasma cells first appeared in the lamina propria of the oviduct at 11 weeks of age, and this frequency peaked at 32 weeks. IgG-containing plasma cells were most numerous in the glandular part, whereas in the aglandular part IgA and IgM cells were more numerous than IgG cells. When 7-day-old-chickens were treated with sex hormones, B lymphocytes and plasma cells appeared 12 h and 5 days after the hormone injection, respectively. Their frequency of occurrence was statistically higher in diethylstibestrol (DES)-treated chickens than in DES plus progesterone-treated chickens. This suggests that the postnatal development of B lymphocytes and plasma cells in the oviduct of the chicken is correlated to estrogen secretion.

Hormonal regulation of T-cell subsets in the oviduct: an immunohistochemical study using sex-hormone-treated chicken

The present immunohistochemical study deals with dynamic alteration of T-cell subsets in the oviduct sex-hormone-treated chickens. Monoclonal antibodies (CT3, CT4, and CT8) specific for the chicken homologues of CD3, CD4, and CD8 were used in estrogen- or progesterone-treated chickens. In control animals, no lymphocytes appeared throughout the oviduct until 4 weeks of age. When 7-day-old chickens were injected with either diethylstilbestrol (DES) or (DES) plus progesterone, T cells immunoreactive for CT3 first infiltrated the oviduct at 12 hr after the hormone treatment. Their frequency of occurrence rose from 48 to 96 hr. Subsequently, CT3+ cells in the magnum declined in number per area coincident with the proliferation of albuminous glands in the lamina propria, while in the vagina no decline of T cells was observed. The population of T-cell subsets in the lamina propria of both the magnum and vagina was significantly higher in the DES-treated chickens than in DES plus progesterone-treated chickens. Among T-cell subsets CT8+ cells were more numerous than CT4+ cells throughout the study, this relative frequency being shared by normal adults. Depopulation of lymphocytes from the thymus, spleen and cecal tonsil, their mobilization to the circulating blood, and subsequent dynamic infiltration into the oviduct suggested that the sex hormones induced the traffic of T cells from the lymphoid organs into the oviduct.

Reversibility of furazolidone-induced changes in testes and secondary sex characters of White Leghorn cockerels

Furazolidone (Fz) was fed to 4 groups of cockerels 15 w of age at 0, 400, 800 and 1200 mg/kg feed for 3 w and then was withdrawn for another 3 w. In a second experiment conducted simultaneously cockerels were fed these same Fz levels for 6 w and then were withdrawn from Fz feed for 4 w. In both experiments, 800 and 1200 mg Fz/kg feed resulted in decreases in comb and wattle size and in the weight of testes. The testes had smaller seminiferous tubule diameters and increased relative and decreased absolute volumes of interstitium. Spermatogenesis was not observed in cockerels fed 800 and 1200 mg Fz/kg feed. Withdrawal of Fz resulted in increased comb and wattle size, weight of testes and diameter of the seminiferous tubules. There was also an increase in absolute volume of interstitium along with decreased relative interstitium volume. Spermatogenesis was restored.

An immunohistochemical analysis of T-cell subsets in the chicken bursa of Fabricius during postnatal stages of development

T-cell subsets in the chicken bursa of Fabricius were analysed immunohistochemically during postnatal stages. Distinct types of T cells were present both in the surface epithelium and lamina propria of the bursa. TcR1+ and CT8+ cells were predominant in the surface epithelium, while TcR2+ and CT8+ cells were numerous in the lamina propria. These T-cell subsets peaked in frequency of occurrence at 5 weeks. They then decreased in number, and a few T cells remained in the bursa until 15 weeks of age. This result showed that the bursa of chickens is furnished with the distinct types of T-cell subsets at early postnatal stages of development to maintain its local immunity.

Tibial reconstruction by ipsilateral vascularized fibular transfer

Between 1979 and 1991 ipsilateral vascularized fibular transposition was performed on eight patients with segmental tibial defects following injury. We report these cases with a minimum follow-up of 2.5 years. All the tibial defects were the result of severe open fractures (Gustilo Grade III) and either bone loss or infected non-union, and ranged in size from 1 to 12 cm. The patients had an average of seven procedures and a delay of 33 months before fibular transfer. The procedure was successful in achieving fracture union in all cases, with an average time to union of 15 months (range, 5-33 months). Shortening of up to 3 cm and some residual ankle stiffness was found, but all patients were ambulating bearing full weight and six had returned to their previous occupation by their final follow-up. Only one patient had significant pain affecting function. This is a successful and relatively simple technique compared to microvascular and bone transport procedures for reconstructing segmental tibial defects with relatively avascular graft beds.