Massive increase in splenic germinal centres of chickens experimentally-infected with Trypanosoma brucei brucei

Domestic chickens infected with Trypanosoma brucei brucei developed a latent parasitaemia which lasted for one year. Six distinct variable antigen types were isolated. Spleens from infected birds were studied histologically at different stages of the infection. Trypanosome infection produced a progressive increase in the number of germinal centres during the early stages of the infection. Peak numbers of germinal centres were reached in the spleen at Day 84 after which the numbers were maintained during an active infection. A tenfold increase in the number of germinal centres was found in trypanosome-infected birds compared to controls. No splenomegaly was observed. Lymphoid cells of the caecal tonsil and the thymus remained apparently normal during the course of infection. Chemotherapeutic termination of infection with berenil resulted in an initial increase in the number of germinal centres. A gradual return to normal level was observed on Day 100 post cure. It is suggested that the development of such a large number of germinal centres reflects the bird's response to the elaboration of a succession of trypanosome variable antigens.     

Monitoring presence and annual variation of trichomoniasis in mourning doves

Information about the annual variation of trichomoniasis in mourning doves (Zenaida macroura) may be important in understanding mechanisms affecting mourning dove populations. The objectives of this study were to monitor the presence and annual variation of Trichomonas gallinae for 6 yr in a local mourning dove population using hunter-killed doves. During 1998-2003, 4052 hunter-killed doves were sampled for the presence of T. gallinae; 226 (5.6%) tested positive (4.4%-10.6% range). Results of the monitoring effort were relatively consistent during the 6-yr period, with the presence of T. gallinae being within the range of previously reported estimates for mourning doves. Asymptomatic carriers in one segment of the dove population may provide a mechanism for spreading the disease to other segments of the mourning dove population.     

Comparison of 3 techniques for ureteroneocystostomy in cats

OBJECTIVE: To compare 3 techniques for ureteroneocystostomy in cats. STUDY DESIGN: Experimental surgical study. ANIMALS: Fifteen adult cats. METHODS: Cats (15) had ureteroneocystostomy with ureteronephrectomy of the contralateral kidney: 5 cats had an intravesical mucosal apposition technique (modified Leadbetter-Politano; intravesical-MA group), 5 cats had extravesical ureteroneocystostomy (modified Lich Gregoir) using a simple continuous suture pattern (extravesical-SC group) and 5 cats had an extravesical technique using a simple interrupted suture pattern (extravesical-SI group). Renal function was evaluated by measuring serum creatinine concentration. Ultrasonographic assessment of the kidney and ureteroneocystostomy site was performed the day after surgery, twice weekly for 3 weeks and once weekly for the remainder of the study. Cats were euthanatized 50 days after surgery. The kidney and ureter removed at surgery, the remaining kidney, ureter, ureteroneocystostomy site, and bladder were examined histologically. RESULTS: Two extravesical-SC cats were euthanatized because of azotemia and uroabdomen, and 1 died acutely at day 4 for unknown reasons. In the intravesical-MA and extravesical-SI cats, the serum creatinine concentration increased after surgery, peaking at a mean (+/-SD) of 9.4+/-2.4 mg/dL and 4.9+/-3.3 mg/dL on day 3, and decreasing to 3.4+/-5.7 mg/dL and 1.5+/-0.4 mg/dL on day 7, respectively. The extravesical-SI technique was associated with consistently lower serum creatinine concentrations for the first week after surgery compared with the other techniques. The mean serum creatinine concentration was within the reference range in cats in the intravesical-MA and extravesical-SI groups by days 10 and 5, respectively. Renal pelvic dilatation occurred in all cats but resolved more rapidly in cats after extravesical techniques. There was no significant difference in serum creatinine concentrations or renal pelvic dilation between the intravesical-MA and extravesical-SI techniques. Bladder mass height at the anastomosis site was significantly larger and persisted for longer with intravesical-MA technique. CONCLUSION: An extravesical-SI technique is seemingly the choice for ureteroneocystostomy in cats with undilated ureters. Renal pelvic dilation on ultrasound examination should be expected after ureteroneocystostomy in cats. CLINICAL RELEVANCE: An extravesical ureteroneocystostomy technique using a simple interrupted pattern for anastomosis should be considered in cats undergoing renal transplantation.     

Ectopic ureterocele in a cat

A 9-month-old, castrated male domestic shorthair cat with urinary incontinence was referred for surgical correction of an ectopic ureter. Excretory urography revealed hydronephrosis of the right kidney, right hydroureter, and ureterocele. A partial ureterocelectomy and neoureterocystostomy were performed. This report describes the surgical modification of the ureterocele and ectopic ureter to correct ipsilateral hydronephrosis, hydroureter, and urinary incontinence.     

Effect of dietary supplementation of chitosan and galacto-mannan-oligosaccharide on serum parameters and the insulin-like growth factor-I mRNA expression in early-weaned piglets

The study was to determine effects of dietary supplementation of chitosan (COS) and galacto-mannan-oligosaccharids (GMOS) on some serum biochemical indices, serum growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels, and hepatic and long gissimus muscle IGF-I mRNA expression in early-weaned piglets. Twenty six Duroc × Landrace × Yorkshire piglets at the age of 15 days were used. The piglets had access to creep feed during the suckling. Six piglets were sacrificed for sampling at the beginning of the study. The other 20 piglets were individually housed in metabolic cages and randomly allotted to four corn and soybean meal-based diets including the control group, the antibiotic group with 110 mg lincomycin/kg diet, the COS group containing 0.025% COS, and the GMOS group with 0.20% GMOS, respectively, in a 2-week feeding experiment. Blood urea nitrogen (BUN) level was reduced whereas serum total protein concentration was increased (P < 0.05) in responses to the COS and GMOS supplementation. Dietary supplementation of COS and GMOS also increased (P < 0.05) the serum GH and IGF-I levels along with enhanced hepatic and the muscle IGF-I mRNA abundance. Dietary supplementation of oligosaccharides such as COS and GMOS may improve growth and feed conversion efficiency by increasing plasma GH and IGF-I levels, in the early-weaned piglets.     

The effects of bimatoprost and unoprostone isopropyl on the intraocular pressure of normal cats

OBJECTIVE: To evaluate the effects on intraocular pressure (IOP), pupillary diameter (PD), blepharospasm score, conjunctival injection score, and aqueous humor flare score when either 0.03% bimatoprost solution is applied once daily or 0.15% unoprostone isopropyl solution is applied twice daily topically to the eyes of normal cats. MATERIALS AND METHODS: The aforementioned parameters were evaluated daily in each of 12 cats throughout the entirety of the study. During an initial 10-day treatment phase a single eye of six of the cats was treated with 0.03% bimatoprost solution while a single eye of the remaining six cats was treated with buffered saline solution (BSS) once daily. During a second 10-day treatment phase a single eye of six of the cats was treated with 0.15% unoprostone isopropyl solution while a single eye of the remaining six cats was treated with BSS twice daily. Contralateral eyes of all cats remained untreated at all time points. RESULTS: Blepharospasm score, conjunctival injection score, and aqueous humor flare score never rose from a value of 0, for any eye of any cat during the study. The mean +/- SD of IOP for eyes treated with 0.03% bimatoprost solution and BSS were 16.55 +/- 3.06 mmHg and 18.02 +/- 3.52 mmHg, respectively. The mean +/- of PD for eyes treated with 0.03% bimatoprost solution and BSS were 5.7 +/- 1.57 mm and 6.39 +/- 1.78 mm, respectively. The mean +/- SD of IOP for eyes treated with 0.15% unoprostone isopropyl solution and BSS were 15.7 +/- 2.91 mmHg and 17.2 +/- 2.9 mmHg, respectively. The mean +/- SD of PD for eyes treated with 0.15% unoprostone isopropyl solution and BSS were 5.8 +/- 1.43 mm and 6.9 +/- 1.37 mm, respectively. There was no significant difference (P > or = 0.05) in IOP or PD between eyes treated with 0.03% bimatoprost solution vs. eyes treated with BSS. Similarly, there was no significant difference (P > or = 0.05) in IOP or PD between eyes treated with 0.15% unoprostone isopropyl solution vs. eyes treated with BSS. CONCLUSION: Neither once daily topical administration of 0.03% bimatoprost solution nor twice daily topical administration of 0.15% unoprostone isopropyl solution significantly affect the IOP of normal cats. Both 0.03% bimatoprost solution and 0.15% unoprostone isopropyl solution induced no significant ocular side effects in normal cats when dosed over a 10-day treatment period.     

The global impact of scaling up HIV/AIDS prevention programs in low- and middle-income countries

A strong, global commitment to expanded prevention programs targeted at sexual transmission and transmission among injecting drug users, started now, could avert 28 million new HIV infections between 2005 and 2015. This figure is more than half of the new infections that might otherwise occur during that period in 125 low- and middle-income countries. Although preventing these new infections would require investing about U.S.$122 billion over this period, it would reduce future needs for treatment and care. Our analysis suggests that it will cost about U.S.$3900 to prevent each new infection, but that this will produce a savings of U.S.$4700 in forgone treatment and care costs. Thus, greater spending on prevention now would not only prevent more than half the new infections that would occur from 2005 to 2015 but would actually produce a net financial saving as future costs for treatment and care are averted.     

Triple-bond reactivity of diphosphorus molecules

We report a mild method for generating the diphosphorus molecule or its synthetic equivalent in homogeneous solution; the P2 allotrope of the element phosphorus is normally obtained only under extreme conditions (for example, from P4 at 1100 kelvin). Diphosphorus is extruded from a niobium complex designed for this purpose and can be trapped efficiently by two equivalents of an organic diene to produce an organodiphosphorus compound. Diphosphorus stabilized by coordination to tungsten pentacarbonyl can be generated similarly at 25 degrees C, and in this stabilized form it still efficiently consumes two organic diene molecules for every diphosphorus unit.     

Absence of detectable arsenate in DNA from arsenate-grown GFAJ-1 cells

A strain of Halomonas bacteria, GFAJ-1, has been claimed to be able to use arsenate as a nutrient when phosphate is limiting and to specifically incorporate arsenic into its DNA in place of phosphorus. However, we have found that arsenate does not contribute to growth of GFAJ-1 when phosphate is limiting and that DNA purified from cells grown with limiting phosphate and abundant arsenate does not exhibit the spontaneous hydrolysis expected of arsenate ester bonds. Furthermore, mass spectrometry showed that this DNA contains only trace amounts of free arsenate and no detectable covalently bound arsenate.     

How the cucumber tendril coils and overwinds

The helical coiling of plant tendrils has fascinated scientists for centuries, yet the underlying mechanism remains elusive. Moreover, despite Darwin's widely accepted interpretation of coiled tendrils as soft springs, their mechanical behavior remains unknown. Our experiments on cucumber tendrils demonstrate that tendril coiling occurs via asymmetric contraction of an internal fiber ribbon of specialized cells. Under tension, both extracted fiber ribbons and old tendrils exhibit twistless overwinding rather than unwinding, with an initially soft response followed by strong strain-stiffening at large extensions. We explain this behavior using physical models of prestrained rubber strips, geometric arguments, and mathematical models of elastic filaments. Collectively, our study illuminates the origin of tendril coiling, quantifies Darwin's original proposal, and suggests designs for biomimetic twistless springs with tunable mechanical responses.