A conjoint analysis of the acute and critical care experiential learning preferences of Baccalaureate student nurses.

With the increasing need for competent nurses specializing in acute and critical care, educators must consider the needs and preferences of students in designing experiential learning programs. This cross-sectional, choice-based conjoint analysis determined the acute and critical care experiential learning preferences of student nurses. From March to July 2016, 213 randomly-selected student nurses from a higher education institution in Manila, Philippines were surveyed and ranked 20 choice bundles with 5 selected attributes of the experiential learning program. Results showed that duration of unit exposure (48.73%) and group structure (7.46%) were the most and least valued attributes, respectively. Additionally, student nurses prefer an experiential learning program that lasts for 1 week (21 h) per unit (utility = 0.93), has a stay-in instructor (utility = 0.30), encourages full student involvement (utility = 1.08), deploys 2-3 students per group (utility = 0.09), and provides both single program and on-going unit orientation (utility = 0.52). Part-worth utilities of duration of unit exposure (t = 3.65, p = 0.0001) and group structure (t = 3.46, p = 0.001) differed between gender. With a model explaining the acute and critical care experiential learning preferences of student nurses, nursing institutions can restructure their clinical placement to maximize positive learning.

Streptozotocin causes pancreatic beta cell failure via early and sustained biochemical and cellular alterations.

The morphological and biochemical changes that occur in the early phase of streptozotocin (STZ)-induced beta cell failure have not been characterized. The pancreas and plasma of rats treated with STZ were processed for morphological and biochemical parameters 1-24 h and 4 weeks after STZ treatment. Marked reduction in body weight was observed as early as 3 h post STZ treatment and hyperglycemia coupled with hypoinsulinaemia appeared in rats 1 h after treatment with STZ. Hyperglycemia, hyperglucagonemia and hypoinsulinemia became permanent 24 h after STZ treatment. The number of insulin-positive cells decreased significantly (p<0.05) at 24 h after STZ treatment with a concomitant increase in the number of glucagon-immunoreactive cells. Electron microscopy showed coalescing of beta cell granules 18 h after STZ treatment. A near to complete degranulation of beta cells settled at 21 h after STZ administration. The pancreatic tissue and plasma levels of adrenaline and noradrenaline increased significantly (p<0.004: pancreatic tissue; p<0.04: plasma) 3 h after STZ treatment and remained high after a reduction at 6 h post STZ treatment. The pancreatic tissue and plasma levels of 5-HIAA decreased significantly (p<0.002 pancreatic tissue; p<0.04: plasma) 1 h after STZ treatment and remained low after a reduction at 6-9 h post STZ treatment. STZ elicited significant dose-dependent increases in insulin secretion from the isolated pancreas. The early changes in catecholamine level may be used in screening and follow-up studies on diabetes mellitus.

Long-term changes in sympathetic innervation in the corpus cavernosum of the STZ-diabetic rat.

The noradrenaline (NA) concentration in the rat corpus cavernosum (CC) increased to approximately 350% of control values after about 8 weeks of hyperglycaemia induced by the intraperitoneal injection of streptozotocin (STZ) at 10 weeks of age. These changes were maintained for at least a further 32 weeks of hyperglycaemia and occurred without any significant change in the weight in the tissue. Smaller but significant increases in NA concentration occurred in the glans penis (GP) reaching 150-175% of the control levels during the period of prolonged hyperglycaemia. In contrast, there was no significant change in the NA concentration in the penile urethra. Measurements have also been made that relate to changes in the synthesis and reuptake of NA in the CC during the period during which high NA concentration is maintained. Immunohistochemical studies for the synthetic enzyme tyrosine hydroxylase in the CC indicate that the intensity of staining in the tissue had increased after 10, 20 and 32 weeks of hyperglycaemia, relative to the tissues from control animals. Dilated nerve fibres and engorged endings were present in the CC of the diabetic animals at these times. Reuptake of tritiated NA by the terminal axonal membranes in the CC was raised to 181% of control values after 12 weeks of hyperglycaemia (P<0.05), but later declined to values that are not significantly different from the control levels (after 26 and 64 weeks of hyperglycaemia). There are few studies of the effects of prolonged diabetes on functional aspects of sympathetic postganglionic neurones in the CC, and this paper suggests that the changes described represent remodelling of noradrenergic axonal terminals starting about after 8-10 weeks of hyperglycaemia; this delay in onset of the neuropathic changes is also a feature of type I diabetes in humans.

Entry of two new asymmetric bispyridinium oximes (K-27 and K-48) into the rat brain: comparison with obidoxime.

In the search for new oximes with higher reactivation potency and a broader spectrum, K-27 and K-48, have recently been synthesized. To test if their superior efficacy was related to better penetration across the blood-brain barrier, their brain entry was compared with that of obidoxime, when administered either alone or after the organophosphate paraoxon (POX). Rats received 50 micromol obidoxime, K-27 or K-48, either alone or in addition to 1 micromol POX. Oxime concentrations at various points in time in brain and plasma were measured using HPLC. The obidoxime C(max) in brain was 1.3% of the plasma C(max) when injected alone, and 1.5% when injected following POX. The ratio of the area under the curve (AUC) brain to plasma for obidoxime was around 6%, irrespective of whether it was administered alone or after POX. For K-27, C(max) (brain) was 0.6% of C(max) (plasma) when injected alone, and 0.7% when injected after POX (no significant difference). The AUC (brain) was 2% of AUC (plasma) for both K-27 groups. K-48, when injected alone reached 1.4% of C(max) (plasma) in the brain and 1.2% of C(max) (plasma), when injected following POX. The AUC (brain) was 5% of the AUC (plasma), both when K-48 was administered alone and in combination with POX. Entry of all three oximes into the brain is minimal and cannot explain the better therapeutic efficacy of K-27 and K-48. As already observed for pralidoxime, injection of POX before oxime administration had no influence upon penetration across the blood-brain barrier.

Paraoxon has only a minimal effect on pralidoxime brain concentration in rats.

Clinical experience with oximes, cholinesterase reactivators used in organophosphorus poisoning, has been disappointing. Their major anatomic site of therapeutic action and their ability to pass the blood-brain barrier (BBB) are controversial. Although their physico-chemical properties do not favour BBB penetration, access of oximes to the brain may be facilitated by organophosphates. The effect of the organophosphate paraoxon (POX) on pralidoxime (2-PAM) brain entry was therefore determined. Rats either received 50 micromol 2-PAM only (G(1)) or additionally 1 micromol POX ( approximately LD(75)) (G(2)). Three animals each were killed after 5, 15, 30, 60, 90, 120, 180, 240, 360, 480 min, and 2-PAM concentrations in the brain and plasma were measured using HPLC. Moreover, the effect of brain perfusion with isotonic saline on subsequent 2-PAM measurements was assessed. The maximal 2-PAM concentration (C(max)) in G(1) brain was 6% of plasma C(max), while in G(2) brains it was 8%. Similarly, the ratio of the area under the curve (AUC) brain to plasma was 8% in G(1) and 12% in G(2). Brain t(max) (15 min) was slightly higher than plasma t(max) (5 min). The AUC of plasma 2-PAM did not differ between G(1) and G(2). However, in G(1), AUC brain was significantly lower than in G(2), the differences probably being clinically irrelevant. In perfused brains, 2-PAM concentrations were very close to those of non-perfused brains. The results indicate that brain penetration of 2-PAM is poor and that organophosphates only have a modest effect on 2-PAM BBB penetration. Brain perfusion does not significantly alter 2-PAM measurements and is therefore considered unnecessary.

The effects of age and streptozotocin diabetes on the sympathetic innervation in the rat penis.

The objective was to describe the changes in catecholamine levels, noradrenaline (NA) release and the ultrastructural and immunohistochemical changes in the sympathetic nerves in the penis of STZ-diabetic rats. Amines were measured using HPLC. Nerves were studied using immunocytochemistry for tyrosine hydroxylase, and electron microscopy. Diabetic animals were compared with age-matched controls. The concentration of penile NA increases at least 2.5-fold after about 10 weeks of hyperglycaemia, is maintained for over 40 weeks. The rate of release of NA in the diabetics also increases approximately by fourfold. Immunohistochemical staining for tyrosine hydroxylase showed either no change or an increase in the levels of the enzyme around the central arteries and the outer coverings of the corpus cavernosum. Cavernosal nerves show increased intensity of staining for tyrosine hydroxylase, and the presence of dilated nerve fibres and engorged endings. The axons of the dorsal nerve of the diabetic penis have a smaller cross-sectional area that is most marked in unmyelinated axons. In the diabetic penis, the nerve endings appear to contain significantly more NA than the controls, and the turnover of noradrenaline is increased substantially. There is immunocytochemical evidence of an increase in staining for tyrosine hydroxylase, suggesting an increase in synthetic activity. These results are discussed in relation to the existing literature on the role of amines in normal and disordered erectile function. In particular, the increased concentration and turnover of NA in the diabetic rat contrasts with the fall in NA in cavernosal blood described during normal erection in humans.

Comparison of two pre-exposure treatment regimens in acute organophosphate (paraoxon) poisoning in rats: tiapride vs. pyridostigmine.

Recently, the FDA approved the medical use of oral pyridostigmine as prophylactic treatment of possible nerve agent exposure: the concept is to block the cholinesterase transitorily using the carbamate (pyridostigmine) in order to deny access to the active site of the enzyme to the irreversible inhibitor (nerve agent) on subsequent exposure. We have shown previously that tiapride is in vitro a weak inhibitor of acetylcholinesterase and that in rats administration of tiapride before the organophosphate paraoxon significantly decreases mortality. The purpose of the present study was to compare tiapride- and pyridostigmine-based pretreatment strategies, either alone or in combination with pralidoxime reactivation, by using a prospective, non-blinded study in a rat model of acute high-dose paraoxon exposure. Groups 1-6 received 1 microMol paraoxon (approximately LD75) groups 2-6 received in addition: G(2)50 microMol tiapride 30 min before paraoxonG(3)50 microMol tiapride 30 min before paraoxon and 50 microMol pralidoxime 1 min after paraoxon G41 microMol pyridostigmine 30 min before paraoxon G(5)1 microMol pyridostigmine 30 min before paraoxon and 50 microMol pralidoxime 1 min after paraoxon G(6)50 microMol pralidoxime 1 min after paraoxon. Mortality data were compared using Kaplan-Meier plots and logrank tests. Mortality is statistically significantly influenced by all treatment strategies. Tiapride pretreatment followed by pralidoxime treatment (G3) is aux par with pyridostigmine pretreatment followed by pralidoxime treatment (G5). Tiapride pretreatment only (G2) is inferior to pyridostigmine pretreatment only (G4). The best results are achieved with pyridostigmine pretreatment only or pralidoxime treatment only (G4 and G6).

HPLC analysis of K-48 concentration in plasma.

K-48 is a new oxime-type compound to be used as an enzyme reactivator in the treatment of exposure to organophosphorous compounds. Plasma concentration of K-48 can be determined using reversed-phase HPLC. Analysis using octyl silica stationary phase and ultraviolet-absorbance detection is fast and simple. K-48 displays a relatively high dose-normalized area under the curve as compared to pralidoxime, which might be beneficial for an antidote. After i.m. administration of 50 mumol K-48, the time course of the concentration can be approximated by a straight line between 15 and 120 min meaning the elimination follows zero-order kinetics.

High-performance liquid chromatographic determination of the plasma concentration of K-27, a novel oxime-type cholinesterase reactivator.

A simple and reliable HPLC method for the determination of the plasma level of K-27, an oxime type antidote of use in organophosphorus poisoning is presented. Separation was carried out by HPLC using an octyl silica stationary phase and a mobile phase consisting of 93% phosphate buffer (pH 2.6) containing octane sulfate sodium salt, and 7% methanol. Quantitative absorbance was monitored at 286 nm. The calibration curve was linear through the range of 1.25-200 microg/mL, that is well beyond the detected plasma level range of K-27. Limit of quantitation was 5 microg/mL. Intra-day and inter-day precisions of the HPLC determinations gave standard deviations as 0.77 and 2.67%, respectively. Following intramuscular administration of 50 micromol (22.31 mg) K-27 in rats, the maximum of K-27 concentration in plasma was reached at about 15 min giving 186 microg/mL and the t(1/2) was 85 min. K-27 displays initial (from 15 trough 120 min) zero order elimination kinetics. Similar results have been found after intraperitoneal administration.

Tiapride pre-treatment in acute exposure to paraoxon: comparison of effects of administration at different points-in-time in rats.

INTRODUCTION: Accidental and suicidal exposures to organophosphorus compounds (OPC) are frequent. The inhibition of esterases by OPC leads to an endogenous ACh poisoning. Recently, the FDA approved, based on animal experiments, for military combat medical use oral pyridostigmine (PSTG) for pre-exposure treatment of soman; the concept is to block the cholinesterase reversibly using the carbamate pyridostigmine in order to deny access to the active site of the enzyme to the irreversible inhibitor (OPC) on subsequent exposure. We have shown previously that tiapride (TIA) is in vitro a weak inhibitor of AChE. We also have shown recently that in rats coadministration of TIA with the organophosphate paraoxon significantly decreases mortality without having an impact on red blood cell cholinesterase (RBC-AChE) activity. PURPOSE OF THE STUDY: To establish in a prospective, non-blinded study in a rat model of acute high dose OPC (paraoxon; POX) exposure the ideal point in time for TIA pre-treatment administration and to correlate it with measured TIA plasma levels. MATERIAL AND METHODS: There were six groups of rats in each cycle of the experiment and each group contained six rats. The procedure was repeated twelve times (cycles) (n = 72 for each arm; half male and half female). All substances were applied ip. All groups (1-6) received 1 microMol POX ( approximately LD(75)); groups 1-5 also received 50 microMol TIA at different points in time. Group 1 (G(1)): TIA 120 min before POX Group 2 (G(2)): TIA 90 min before POX, Group 3 (G(3)): TIA 60 min before POX, Group 4 (G(4)): TIA 30 min before POX, Group 5 (G(5)): TIA & POX simultaneously, Group 6 (G(6)): POX only. The animals were monitored for 48 hours and mortality/survival times were recorded at 30 min, 1, 2, 3, 4, 24 and 48 h. AChE activities were determined at 30 min, 24 and 48 h in surviving animals. Statistical analysis was performed on the mortality data, cumulative survival times and enzyme activity data. Mortality data was compared using Kaplan-Meier plots. Cumulative survival times and enzyme activites were compared using the Mann-Whitney rank order test. No Bonferroni correction for multiple comparisons was applied and an alpha < or= 0.05 was considered significant. RESULTS: Mortality is statistically significantly reduced by TIA pre-treatment at all points-in-time. Highest protection is achieved if TIA is given 90 to 0 min before OPC exposure. The reduction in mortality is not correlated to TIA plasma levels (C (max) approximately 120 min post ip-administration). TIA pre-treatment is not affecting AChE activity regardless of the timing of administration. CONCLUSION: The lack of correlation between TIA plasma levels and degree of mortality reduction as well as the lack of protective effect on enzyme activity seem to indicate that the site of action of TIA is not the blood. While our hypothesis that TIA would protect AChE in a pyridostigmine-like manner (via protection of the enzyme) could not be confirmed, the reduction in mortality with TIA pre-treatment is nevertheless of potential interest.

Effects of age and streptozotocin-induced diabetes on biogenic amines in rat tail artery.

The changes in amine concentrations in different segments of the rat tail artery have been investigated at different ages and after different durations of streptozotocin-induced diabetes. There was a significant positive slope to the relationship between amine concentrations and age in proximal portion of the normal tail artery, and a significant additional increase in amine concentrations following induction of diabetes. The peak of the latter response occurred between 10 and 20 weeks following the induction of diabetes. There was also a significant dependence on the length of the post-ganglionic neurones, which may be related to the failure of axonal transport of some of the essential enzymes or transporters for these biogenic amines. This model of altered catecholamine metabolism and handling requires further investigation so that alterations in the mechanisms involved in processing of these amines in diabetic autonomic neuropathy may be elucidated.

Factores que afectan la producción de leche en vacas de doble propósito en trópico húmedo (Pucallpa) / Factors affecting milk production in dual purpose cows in the humid tropics (Pucallpa)

Se evaluó el efecto de la alimentación, grupo racial, etapa de lactancia y estado reproductivo sobre la producción láctea en vacas de doble propósito en trópico húmedo. Se utilizaron 402 vacas distribuidas en 23 fundos. Todas las vacas pastoreaban sobre Brachiaria decumbens. La suplementación energética consistió en residuo de cervecería y/o polvillo de arroz. Las vacas fueron asignados a 3 grupos raciales (Bajo, Medio y Alto mestizaje europeo). El análisis estadístico fue por regresiones y "t" Student. Los resultados indicaron que el promedio de producción láctea fue de 4.3 kg/vaca/día. La mayor disponibilidad de B. decumbens tuvo un efecto negativo sobre la producción de leche. Animales suplementados produjeron más leche (5.2 kg/vaca/día) que los no suplementados (3.8 kg/vaca/día). El grupo racial afectó la producción de leche, donde las vacas con medio mestizaje europeo fueron los que más leche produjeron (5.0 kg/vaca/día). El mes de lactancia afectó el rendimiento lácteo de los animales, y las vacas vacías produjeron más leche que las gestantes (4.5 vs. 3.7 kg/vaca/día). Se concluye que la producción de leche estuvo afectada por todas las variables en estudio, pero principalmente por el tipo racial.

The effect of feeding, crossbreeding level, lactation period, and reproductive status on milk yield was evaluated in dual purpose cows in the humid tropics of Peru. A total of 204 cows from 23 farms were monitored. All cows grazed over Brachiaria decumbens. Energy supplementation consisted of brewery residues and rice bran. Cows were grouped according to the level of European blood in Low, Medium, and High. Regression analysis and the "t" Student test were applied for statistical comparisons. The higher availability of B. decumbens had a negative effect on milk yield. Supplemented animals yielded more milk (5.2 kg/cow/day) than those non-supplemented (3.8 kg/cow/day). The level of European inheritance affected milk yield, where 50% crossbred cows had the highest milk yield (5.0 kg/cow/day). Month of lactation affected productive performance. Non-pregnant cows produced more milk than the pregnant ones (4.5 vs. 3.7 kg/cow/day). It is concluded that milk yield was affected by all variables under evaluation, especially the level of European blood.

Effect of alpha-tocopherol supplementation on the ultrastructural abnormalities of peripheral nerves in experimental diabetes.

Ultrastructural observations were made on myelinated fibers in the tibial nerves in order to investigate the beneficial effects of alpha-tocopherol administration in streptozotocin-diabetic rats. Male Wistar rats, aged 12 weeks and weighing between 250 g to 300 g were studied. Six onset control rats were used to obtain the baseline parameters for this strain and age. Further 3 groups--untreated diabetic animals, diabetic animals treated with alpha-tocopherol, and age-matched controls--were studied over a 3-month period. In the diabetic animal, administration of alpha-tocopherol resulted in a significant increase (p < 0.05) in total plasma vitamin E levels when compared with other groups. Myelinated fiber cross-sectional area (p < 0.05), axonal area (p < 0.01) and myelin sheath area (p < 0.05) were significantly less in the tibial nerve of diabetic animals than in age-matched controls, but not different from those of onset controls. In the alpha-tocopherol treated diabetic animals, the values for these parameters were intermediate without showing significant difference when compared with age-matched controls and untreated diabetics. The "g" ratio (axon to fiber area) did not differ between any experimental groups. The number of large myelinated fibers were less in the untreated diabetic animals, but in the alpha-tocopherol-treated diabetics, the values were significantly higher (p < 0.05) than with untreated diabetics and were similar to those of age-matched controls. In conclusion, this ultrastructural study reiterated the fact that structural abnormalities of myelinated fibers occur in experimental diabetes and that alpha-tocopherol administration may be useful in preventing the development of these abnormalities.

Streptozotocin-Induced diabetes mellitus is associated with increased pancreatic tissue levels of noradrenaline and adrenaline in the rat.

The pancreata of streptozotocin-induced diabetic rats were examined to determine whether the pancreatic tissue content of catecholamines is altered after the onset of diabetes. Experimental diabetes was induced by intraperitoneal injection of streptozotocin (60 mg/kg body weight). Four weeks after the induction of diabetes, pancreatic tissue fragments were taken from the tail end of the pancreas and processed for catecholamine content using the high-performance liquid chromatography method. Immunohistochemical analysis showed that the pancreata of diabetic rats contained more tyrosine hydroxylase-positive nerves compared with controls. Pancreatic noradrenaline content, expressed as the mean +/- SD, was significantly (p < 0.03) greater in diabetic rats (54+/-11.74 pg x mL(-1) x mg tissue(-1)) compared with normal, sex- and age-matched control rats (37.54+/-1.18 pg x mL(-1) x mg tissue(-1)). Similarly, the adrenaline content in diabetic rat pancreatic tissue (102.69+/-20.24 pg x mL(-1) mg tissue(-1)) was markedly greater (p < 0.003) compared with sex- and age-matched controls (35+/-9.23 pg x mL(-1) x mg tissue(-1)). In contrast, 5-hydroxyindole acetic acid decreased significantly (p < 0.0002) in diabetic pancreatic tissue (13.41+/-0.87 pg x mL(-1) x mg tissue(-1)) compared with controls (80.72+/-1.46 pg x mL(-1) x mg tissue(-1)). The plasma levels of these catecholamines also increased slightly but not significantly in diabetic rats compared with controls. These results suggest that diabetes is associated with increased noradrenaline and adrenaline and decreased 5-hydroxyindole acetic acid pancreatic tissue levels. These disturbances in catecholamine metabolism may play a role in the pathogenesis of the acute and chronic complications of diabetes mellitus.

Catecholamines in the heart and adrenal gland of the STZ-diabetic rat.

The concentrations of noradrenaline (NA), adrenaline (ADR), 5-hydroxyindoleacetic acid (5-HIAA), serotonin (5-HT) and dopamine (DOP) have been studied in the left ventricle and the left adrenal gland of control and streptozotocin (STZ) - treated rats at various intervals (12, 24, 30, 34, 38 and 42 weeks) after the induction of diabetes. The only amines detected in the heart were NA, 5-HIAA and DOP, whereas those detected in the adrenal gland were NA and ADR. Differential changes in the catecholamine concentrations occurred in the heart and the adrenal gland at different stages of the metabolic disorder. In the heart the initial changes in short-term diabetes included an increase in NA concentration but this did not persist in the longer term diabetic animals (30-38 weeks following STZ injection). In the adrenal gland there was an initial reduction followed by a steady increase in the concentration of NA and ADR throughout the period of the study.

Pharmacokinetics of enrofloxacin after intravenous, intramuscular and oral administration in houbara bustard (Chlamydotis undulata macqueenii).

The in-vitro activity of enrofloxacin against 117 strains of bacteria isolated from bustards was determined. Minimum inhibitory concentrations for 72% of the Proteus spp., E. coli, Salmonella spp. and Klebsiella spp. (n = 61) and for 48% of the Streptococci spp. and Staphylococci spp. (n = 31) were < or = 0.5 microg/mL. The minimum inhibitory concentration (MIC) of 76% of Pseudomonas spp. (n = 25) was < or = 2 microg/mL. Fourteen strains were resistant to concentrations > or = 128 microg/mL. The elimination half-lives (t1/2 elim beta) (mean +/- SEM) of 10 mg/kg enrofloxacin in eight houbara bustards (Chlamydotis undulata) were 6.80 +/- 0.79, 6.39 +/- 1.49 and 5.63 +/- 0.54 h after oral (p.o.), intramuscular (i.m.) and intravenous (i.v.) administration, respectively. Enrofloxacin was rapidly absorbed from the bustard gastro-intestinal tract and maximum plasma concentrations of 1.84 +/- 0.16 microg/mL were achieved after 0.66 +/- 0.05 h. Maximum plasma concentration after i.m. administration of 10 mg/kg was 2.75 +/- 0.11 microg/mL at 1.72 +/- 0.19 h. Maximum plasma concentration after i.m. administration of 15 mg/kg in two birds was 4.86 microg/mL. Bioavailability was 97.3 +/- 13.7% and 62.7 +/- 11.1% after i.m. and oral administration, respectively. Plasma concentrations of enrofloxacin > or = 0.5 microg/mL were maintained for at least 12 h for all routes at 10 mg/kg and for 24 h after i.m. administration at 15 mg/kg. Plasma enrofloxacin concentrations were monitored during the first 3 days of treatment in five houbara bustards and kori bustards (Ardeotis kori) with bacterial infections receiving a single daily i.m. injection of 10 mg/kg for 3 days. The mean plasma enrofloxacin concentrations in the clinical cases at 27 and 51 h (3.69 and 3.86 microg/mL) and at 48 h (0.70 microg/mL) were significantly higher compared with the 3 h and 24 h time intervals from clinically normal birds. The maximum plasma concentration (Cmax)/MIC ratio was ranked i.v. (10/mg/kg) > i.m. (15 mg/kg) > i.m. (10 mg/kg) > oral (10 mg/kg), but it was only higher than 8:1 for i.v. and i.m. administrations of enrofloxacin at 10 mg/kg and 15 mg/kg, respectively, against a low MIC (0.5 microg/mL). A dosage regimen of 10 mg/kg repeated every 12 h, or 15 mg/kg repeated every 24 h, would be expected to give blood concentrations above 0. 5 microg/mL and hence provide therapeutic response in the bustard against a wide range of bacterial infections.

In the absence of periosteum, transplanted fetal and neonatal rat coronal sutures resist osseous obliteration.

Normal craniofacial development depends on expansion of the cranial vault by growth at the sutures. Inappropriate development of the sutures leads to global disruption of patterns of craniofacial growth. Tissue interactions between dura mater and suture matrix play a critical role in the phenotypic maintenance of cranial sutures. However, the function of the periosteum in this process remains under-reported and controversial. To examine the contribution of periosteum in maintaining the patency of coronal sutures, fetal and neonatal rat coronal sutures were transplanted to surgically created defects in adult rat host parietal bones. These sutures were examined for their ability to persist in the host milieu in the presence and absence of both donor and host periosteum. This study established that removal of both host and transplant periosteum, unlike removal of dura mater, did not lead to obliteration of either fetal or neonatal sutures. Thus, periosteum and dura mater are nonequivalent tissues with respect to influence on suture patency.

Reconstruction of intraoral mucosal defects with revascularized jejunal segments.

The intraoral mucosa subserves a multitude of structural and functional roles. This paper details the importance of this within the context of reconstruction. The various methods are reviewed historically. Also, both the experimental and clinical basis for using revascularized jejunum as mucosal reconstruction are presented.

Surgical correction of Crouzon syndrome.

This study analyzes the results of surgical treatment in 39 patients with the Crouzon syndrome. Early fronto-orbital advancement and craniectomy were universally successful in relieving raised intracranial pressure and in reducing ocular proptosis. However, definitive cosmetic correction was not achieved, and early cranial surgery was not able to prevent the development of midface hypoplasia. Thirty-two midfacial advancements have been performed in 30 patients. Sixteen patients had sufficient follow-up data for more than 2 years postoperatively. In all patients, a satisfactory early postoperative result was achieved. In the long-term follow-up group, 11 patients have maintained a satisfactory appearance, while 5 have developed recurrent deformity. Analysis shows this to be associated with a younger age at operation and continued mandibular growth. Frontofacial advancement in adults achieves good long-term results but is associated with a higher incidence of complications.