Engineering gibberellin metabolism in Solanum nigrum L. by ectopic expression of gibberellin oxidase genes.

Gibberellins (GAs) control many aspects of plant development, including seed germination, shoot growth, flower induction and growth and fruit expansion. Leaf explants of Solanum nigrum (Black Nightshade; Solanaceae) were used for Agrobacterium-mediated delivery of GA-biosynthetic genes to determine the influence of their encoded enzymes on the production of bioactive GAs and plant stature in this species. Constructs were prepared containing the neomycin phosphotransferase (nptII) gene for kanamycin resistance as a selectable marker, and the GA-biosynthetic genes, their expression under the control of the CaMV 35S promoter. The GA-biosynthetic genes comprised AtGA20ox1, isolated from Arabidopsis thaliana, the product from which catalyses the formation of C(19)-GAs, and MmGA3ox1 and MmGA3ox2, isolated from Marah macrocarpus, which encode functionally different GA 3-oxidases that convert C(19)-GAs to biologically active forms. Increase in stature was observed in plants transformed with AtGA20ox1, MmGA3ox2 and MmGA3ox1 + MmGA3ox2, their presence and expression being confirmed by PCR and RT-PCR, respectively, accompanied by an increase in GA(1) content. Interestingly, MmGA3ox1 alone did not induce a sustained increase in plant height, probably because of only a marginal increase in bioactive GA(1) content in the transformed plants. The results are discussed in the context of regulating plant stature, since this strategy would decrease the use of chemicals to promote plant growth.

The hidden dangers of staying home: a London trauma unit experience of lockdown during the COVID-19 virus pandemic.

INTRODUCTION: The COVID-19 pandemic resulted in reconfiguration of the NHS. Elective services were stopped and trauma services focused on decreasing patient-clinician interactions and managing injuries nonoperatively wherever possible. The everyday life of the general public changed dramatically with the introduction of a national lockdown to prevent the spread of COVID-19. This paper looks at the experience of a South West London trauma unit. MATERIALS AND METHODS: All patients reviewed in fracture clinic and by the orthopaedic on-call team between 23 March to 23 April 2020 were included. Data on the mechanism of injury and whether this was a usual activity, the injury sustained and its management were collected. RESULTS: A total of 167 trauma injuries were seen, compared with 735 new patients with injuries in the previous month. The number of trauma operations completed decreased by 38%; 55% of injuries occurred inside the home and 44% outside the home during daily exercise. Some 31% of injuries were secondary to a new activity taken up during lockdown. Three open fractures and two polytrauma cases were seen that would have normally been managed at the local major trauma centre. CONCLUSION: Overall, both the number of injuries seen and trauma operations completed during the enforced lockdown decreased. This is probably due to a change in the way the general public are living their lives, and the reconfigurations within the NHS in response to the COVID-19 pandemic. This is an interesting time within trauma and orthopaedic departments, as they continue to adapt to the changing injuries and working environment.

The histopathology of freezing injury to the rat spinal cord. A light microscope study. I. Early degenerative changes.

In an effort to develop a method of tissue injury which would provide a model for the study of axonal regrowth in adult mammalian central nervous system (CNS), we have analyzed the effects of freezing in the dorsal columns of more than 200 rat spinal cords. The effects of temperature and time of exposure upon the size, shape, distribution and histologic characteristics of the lesion have been assessed during the first seven days following the injury. The upper threshold for injury occurs at -3 degrees C for 15 minutes. Between -3 degrees C and -12 degrees C the tissue changes vary in extent and characteristics. Selective damage to axons and myelin occurs with sparing of the supportive cells followed by proliferation of a cellular matrix. At seven days, the lesions produced by -8 degrees C for 15 to 60 minutes have neither axons nor myelin sheaths and consist of a dense cellular matrix of macrophages and presumed glial cells. With these tissue characteristics, and the preservation of tissue continuity without obstructive barriers, this model would appear to be potentially suitable for the study of axonal regrowth potential in mammalian CNS.

Differential responses of prelactating and lactating mammary gland to similar tissue concentrations of progesterone.

Serum and mammary tissue concentrations of progesterone and 20alpha-hydroxy-4-pregnen-3-one (20alpha-OHP) were measured by competitive protein-binding assays and gas-liquid chromatography, respectively, in pregnant and lactating rats. The concentration of progesterone in mammary tissue of pregnant rats closely paralleled the serum concentration, particularly when tissue concentration was expressed as ng/mg DNA. The variability in tissue progesterone on the last day of pregnancy was relatively great, but there was a good inverse relation between the appearance of lactose and the progesterone concentration. Serum progesterone levels declined to their lowest values at 1-3 days of lactation (10 plus or minus 1 ng/ml); the tissue concentration declined even more rapidly after parturition. The tissue 20alpha-OHP concentration, which was more closely related to serum progesterone among animals than to serum 20alpha-OHP, remained high after parturition suggesting that the presence of 20alpha-OHP has no effect on lactogenesis and that progesterone is decreased in the tissue by 20alpha-reduction. Following postpartum ovulation, serum progesterone increased to 74 plus or minus 6 ng/ml at 6-9 days of lactation; tissue progesterone also increased to levels found in rats pregnant 14-19 days, yet no change in lactose content of the glands of suckled rats occurred, and the biosynthetic capacity in terms of the RNA/DNA ratio increased. Serum 20alpha-OHP also rose, but the tissue concentration was unchanged, suggesting that saturating levels were present throughout pregnancy and lactation. Since no rapid increase in DNA was associated with lactogenesis, differentiation of nonsecretory parenchymal cells into daughter cells with the secretory capacity must occur earlier in pregnancy. Progesterone, therefore, must inhibit lactogenesis by preventing expression of the genetic potential of daughter cells. Once differentiation has been completed, however, the presence of progesterone in the tissue has no effect on the biosynthesis of milk constituents.

Spontaneous canine keratoconjunctivitis sicca. A useful model for human keratoconjunctivitis sicca: treatment with cyclosporine eye drops.

Thirty-six sequential cases of canine keratoconjunctivitis sicca (KCS) were treated with ophthalmic cyclosporine. The effects of topical cyclosporine were twofold: (1) cyclosporine increased tear production by 5 mm/min or greater in all cases of spontaneous KCS having an initial Schirmer's Tear Test value greater than 2 mm/min and in 59% of eyes with an initial Schirmer's Tear Test value of 0 to 2 mm/min, and (2) cyclosporine caused marked regression of chronic corneal neovascularization and granulation even in eyes in which lacrimation failed to improve. Additional benefits of topical cyclosporine were reduced mucopurulent conjunctivitis, rapid healing of nonhealing corneal ulcers, and reduced dependence on frequent topical treatments of KCS. Twelve normal beagles treated with topical cyclosporine also had a reversible increase in lacrimation compared with baseline or placebo control-treated dogs.

Caprolactam-barbiturate interaction at the GABAA receptor complex in the guinea-pig intestine.

4,6,6-Trimethylcaprolactam antagonised GABAA receptor-mediated contractile responses in guinea-pig isolated ileum, displacing the GABA dose-response curve to the right in a non-parallel manner, and causing a depression of the maximum response. Pentobarbitone not only potentiated the GABAA receptor-mediated contractions but also reversed this non-competitive antagonism by 4,6,6-trimethylcaprolactam, shifting the dose-response curve for GABA to the left and restoring the maximum response. It is conclude that this caprolactam acts at the picrotoxin-barbiturate site on the Cl(-)-ionophore complex.

Effects of blood alcohol concentrations on negative punishment: implications for decision making.

OBJECTIVE: A series of studies examined how various blood ethanol concentrations influenced the effectiveness of a negative punishment procedure in a risk-taking/decision-making task. Based on the animal punishment literature plus the impression that ethanol diminishes the effects of punishment and impairs decision making, it was predicted that individuals receiving alcohol would increase their risk- taking behavior despite the presence of a negative punishment stimulus (point loss) given on a variable schedule. METHODS: In Experiment 1, a within-subjects design with repeated measures was used where 10 male subjects played a modified computer-generated choice game under three levels of punishment certainty, three levels of punishment severity and four ranges of blood ethanol (0.00%, 0.01-0.049%, 0.050-0.099%, 0.10-0.15%) RESULTS: Results indicated significant decreases in risk taking as either punishment certainty or severity was increased. However, no significant effects were found for ethanol, or interactions of ethanol with punishment certainty or punishment severity. Two additional studies examining aspects of the experimental procedure produced similar results CONCLUSIONS: Overall, the results of these studies do not support the hypothesis that high concentrations of blood alcohol are sufficient in and of themselves to eliminate the suppression function of negative punishment contingencies leading to increased risk-taking behavior. The implications of these results for understanding blood alcohol effects are discussed.

Muscle Balance between Hamstrings and Quadriceps during Isokinetic Exercise.

The maximum flexor and extensor peak torques about the knee joint of 17 male and 17 female subjects were determined using a CYBEX isokinetic dynamometer. These values were used to evaluate the influence of changing joint angular-velocity on the ratio of peak hamstrings torque to peak quadriceps torque. Additionally, an assessment of the influence of gravity on the recorded peak torques, and thus the ratio, was made Values for the flexion-extension ratio corrected for gravity were found not significantly different at the measured joint angular-velocities whereas the values of the ratio not corrected for gravity were found significantly different at increasing joint angular-velocities It is necessary that the physiotherapist recognize the importance of the influence of gravity when recording forces developed in the vertical plane.

Comparative efficacy of topically applied flurbiprofen, diclofenac, tolmetin, and suprofen for the treatment of experimentally induced blood-aqueous barrier disruption in dogs.

OBJECTIVE: To compare the relative efficacies of 4 topical nonsteroidal anti-inflammatory drugs at preventing blood-aqueous barrier (BAB) disruption in dogs. DESIGN: 1 eye of each dog was treated with 1% suspensions of diclofenac, flurbiprofen, suprofen, or tolmetin, or with control solution. After 4 applications of eyedrops at 10-minute intervals, BAB disruption was induced in the treated eye by anterior chamber paracentesis. The severity of BAB disruption was measured by anterior chamber fluorophotometry. ANIMALS: 40 ocular-normal dogs. PROCEDURE: After pretreatment with eyedrops, rapid 100-microliters nonleaking anterior chamber paracentesis was performed in 1 eye of each dog to induce BAB disruption. 1 day after paracentesis, 1 ml of 10% fluorescein sodium was injected i.v.. The amount of fluorescein entering the anterior chamber of each eye was measured 30 to 60 minutes later by use of a computerized scanning fluorophotometer. The degree of BAB disruption was determined by comparing the amount of fluorescein entering the aqueous humor of the paracentesed eye with that of the nonparacentesed eye. RESULTS: At postparacentesis day 1, the order of statistically significant BAB-stabilizing efficacy among groups was: diclofenac > flurbiprofen > suprofen > tolmetin = control solution. CONCLUSIONS: Topically applied 1% suspensions of diclofenac, flurbiprofen, and suprofen are effective at preventing BAB disruption after paracentesis in dogs, indicating their potential usefulness for treatment of prostaglandin-mediated ocular disease. 1% tolmetin is no more effective than control solution.

Effects of antibiotics on morphologic characteristics and migration of canine corneal epithelial cells in tissue culture.

OBJECTIVE: To determine effects of commonly used ophthalmic antibiotics on cellular morphologic characteristics and migration of canine corneal epithelium in cell culture. SAMPLE POPULATION: Corneal epithelial cells harvested from corneas of 12 euthanatized dogs and propagated in cell culture. PROCEDURE: Cells were treated with various antibiotics after a defect was created in the monolayer. Cellular morphologic characteristics and closure of the defect were compared between antibiotic-treated and control cells. RESULTS: Cells treated with ciprofloxacin and cefazolin had the greatest degree of rounding, shrinkage, and detachment from plates. Cells treated with neomycin-polymyxin B-gramicidin and gentamicin sulfate had rounding and shrinkage but with less detachment. Cells treated with tobramycin and chloramphenicol grew similarly to control cells. On the basis of comparisons of defect circumference between control cells and cells exposed to antibiotics, tobramycin affected cellular migration the least. CONCLUSIONS AND CLINICAL RELEVANCE: Effects of ciprofloxacin and cefazolin on morphologic characteristics of canine corneal epithelial cells in vitro should be taken into consideration before using these antibiotics for first-line of treatment for noninfected ulcers. Of the antibiotics tested that have a primarily gram-negative spectrum of coverage, gentamicin inhibited corneal epithelial cell migration and had greater cytopathologic effects than tobramycin did. For antibiotics with a gram-positive coverage, chloramphenicol had no cytopathologic effects on cells in comparison to cefazolin, which caused most of the cells to shrink and detach from the plate. Polymyxin B-neomycin-gramicidin was midrange in its effects on cellular morphologic characteristics and migration.

Fluorophotometric determination of aqueous humor flow rate in clinically normal dogs.

OBJECTIVE: To determine aqueous humor flow rate in clinically normal dogs, using fluorophotometry. ANIMALS: 20 clinically normal Beagles. PROCEDURE: A study was performed on 5 dogs to establish an optimal protocol for fluorophotometric determination of aqueous humor flow rate. This protocol then was used to measure aqueous humor flow rate in 15 dogs. Corneas were loaded with fluorescein by topical application, and corneal and aqueous humor fluorescein concentrations were measured 5, 6.5, and 8 hours after application. Concentration-versus-time plots were generated, and slopes and ratios of the fluorescein concentration in the cornea and aqueous humor from these graphs were used to calculate flow rates. Calculations were performed by use of automated software provided with the fluorophotometer and by manual computation, and the 2 calculation methods were compared. RESULTS: The protocol established for the 5 dogs resulted in semilogarithmic and parallel decay of corneal and aqueous humor concentrations. Manually calculated mean +/- SD aqueous humor flow rates for left, right, and both eyes were 5.58 +/- 2.42, 4.86 +/- 2.49, and 5.22 +/- 1.87 microl/min, respectively, whereas corresponding flow rates calculated by use of the automated software were 4.54 +/- 3.08, 4.54 +/- 3.10, and 4.54 +/- 2.57 microl/min, respectively. Values for the left eye were significantly different between the 2 computation methods. CONCLUSIONS AND CLINICAL RELEVANCE: Aqueous humor flow rates can be determined in dogs, using fluorophotometry. This technique can be used to assess pathologic states and medical and surgical treatments that alter aqueous humor dynamics.

Effects of topical application of a 2% solution of dorzolamide on intraocular pressure and aqueous humor flow rate in clinically normal dogs.

OBJECTIVE: To evaluate effects of topical application of a 2% solution of dorzolamide on intraocular pressure (IOP) and aqueous humor flow rate in clinically normal dogs. ANIMALS: 15 Beagles. PROCEDURE: The IOP was measured in both eyes of all dogs for 3 days to determine baseline values. In a single-dose study, 50 microl of dorzolamide or control solution was applied in both eyes at 7:00 AM, and IOP was measured 7 times/d. In a multiple-dose study, dorzolamide or control solution was applied to both eyes 3 times/d for 6 days, and IOP was measured 4 times/d during treatment and for 5 days after cessation of treatment. Aqueous humor flow rate was measured for all dogs fluorophotometrically prior to treatment and during the multiple-dose study. RESULTS: In the single-dose study, dorzolamide significantly decreased IOP from 30 minutes to 6 hours after treatment. Mean decrease in IOP during this time span was 3.1 mm Hg (18.2%). Maximal decrease was detected 6 hours after treatment (3.8 mm Hg, 22.5%). In the multiple-dose study, dorzolamide decreased IOP at all time points, and maximal decrease was detected 3 hours after treatment (4.1 mm Hg, 24.3%). Mean aqueous humor flow rate decreased from 5.9 to 3.4 microl/min (43%) after treatment in the dorzolamide group. CONCLUSIONS AND CLINICAL RELEVANCE: Topical application of a 2% solution of dorzolamide significantly decreases IOP and aqueous humor flow rate in clinically normal dogs. Therefore, topical administration of dorzolamide should be considered for the medical management of dogs with glaucoma.

Fluorophotometric evaluation of experimental blood-aqueous barrier disruption in dogs.

A protocol for performing slit-lamp fluorophotometry of the anterior chamber in dogs was established. The technique was then used to develop a model of blood-aqueous barrier disruption that can be used for comparative testing of ophthalmic anti-inflammatory drugs. It was determined that barrier disruption induced by a slow, controlled paracentesis of a small volume of aqueous humor may provide the most reliable model for drug testing. Additionally, fluorophotometry proved to be a sensitive and accurate means of detecting breakdown of the blood-aqueous barrier.

Squamous cell carcinoma of the corneoscleral limbus in a dog.

Squamous cell carcinoma is an uncommon tumor of the cornea in dogs. A 12-year-old Shih Tzu with a history of chronic keratoconjunctivitis sicca was diagnosed as having squamous cell carcinoma of the corneoscleral limbus. The lesion was treated by surgical resection and cryotherapy. One year after surgery, multiple tumors, apparently unrelated to the first tumor, appeared on the same cornea. Keratoconjunctivitis sicca may have predisposed the dog to corneal squamous cell carcinoma development.

Ocular pharmacology.

Application of sound ocular therapeutic principle is more difficult in food animals than most other species. Financial or husbandry constraints limit the practitioner's ability to use the entire range of ocular drugs available or to use them with adequate frequency. These problems may be dealt with by using systemically administered drugs when effective or by employing vehicles or delivery techniques that necessitate minimal dosing frequency. By far the most important medically treatable eye disease encountered in food animal practice is IBK. Effective therapies include systemic administration of long-acting oxytetracycline, subconjunctival administration of a variety of antibiotics, or topical application of benzathine cloxacillin. Infectious conjunctivitis in sheep and goats due to a variety of agents may be treated successfully with tetracycline in most cases. Conjunctivitis and keratitis secondary to IBR virus usually are given supportive therapy only, although specific antiviral drugs have been used in the treatment of herpetic eye disease in other species. Anterior uveitis is best treated by corticosteroid and mydriatic therapy in addition to treatment of the underlying cause, if identified.

Migration of the uncemented CLS acetabular component.

The migration of uncemented press-fit CLS (Cementless Total Hip Replacement System) acetabular cups was measured retrospectively from standard anteroposterior pelvic radiographs using a digitizer and software specifically developed for this study. A radiographic and clinical review also were undertaken. There were 96 patients in the study group. The mean follow-up for radiographic review was 2.23 years, and the mean follow-up for clinical review was 3 years. Migration was measured in the cranial and medial directions. Mean migration of the cup at 2 years was 1.35 mm in the cranial direction and 2.15 mm in the medial direction. Radiographic appearances altered little over the study period. Fifty-five (57.3%) patients demonstrated bone ingrowth onto the prosthesis, predominantly in DeLee and Charnley zone 1. Twenty-one patients demonstrated nonprogressive sclerotic lines; no lucent lines were encountered. Statistical analysis showed a significant correlation between acetabular ingrowth and reduced cup migration in the medial direction (P = .011 at 5 years). There was no statistical relationship between migration of the cup and radiographic features or clinical outcome.

Migration of the uncemented CLS femoral component.

The migration of uncemented CLS (Cementless Total Hip Replacement System) femoral stems was measured retrospectively from standard anteroposterior pelvic radiographs using a digitizer and software specifically designed for this study. The study population was comprised of 117 patients with 126 uncemented CLS femoral stems. All radiographs were reviewed and the incidence of thigh pain obtained by means of a questionnaire. The mean clinical follow-up was 3 years and the mean follow-up for radiographic review was 2.77 years. The mean femoral stem migration was 2 mm at 2 years and 3.66 mm at 7 years. Radiographic features varied little with no specific predictive features in patients with excessive early migration or those who complained of thigh pain. There was no statistical relationship between the presence of thigh pain and femoral stem migration.

Orbital plasmacytoma in a cat.

An Abyssinian cat presented with epistaxis, melaena and retinal vascular changes. Plasma protein levels were markedly elevated and a monoclonal gammopathy was present on serum protein electrophoresis. Based on these laboratory findings, hyperviscosity syndrome was assumed to be responsible for the clinical signs. The cat responded initially to fluid therapy, but relapsed and then developed unilateral exophthalmia. The animal was euthanased and an extramedullary plasmacytoma of the right orbit was diagnosed at postmortem examination.

Is revision surgery following lower-limb amputation a worthwhile procedure? A retrospective review of 71 cases.

There is little written about the value of revision surgery on lower-limb amputations. We report on 71 revision amputation procedures performed by a single surgeon in this retrospective analysis. The majority of our revisions (61%) were in amputees who had suffered trauma. We judged success from a surgical and a rehabilitation perspective using scoring systems. Revisions for bony and soft-tissue pathology had good outcomes from a surgical (85% and 82%) and a rehabilitation perspective. Revisions for infection had satisfactory results from a surgical perspective (73%) but less so from a rehabilitation perspective (25%). The results of the revisions for pain were poor showing surgical success only 50% of the time where a neuroma was suspected and only 25% when there was no apparent cause. There was little or no improvement in rehabilitation in both the pain groups. Revision surgery for certain pathologies gives a good surgical outcome and can improve pain and mobility status. Patient selection for surgery is key and evaluation by a multidisciplinary team is recommended.