Mechanical testing of lid speculae and relationship to postoperative ptosis.

AIMS: Postoperative lid malpositions are known complications of routine intraocular surgery and were previously attributed to the use of a bridle suture or the myotoxic effect of retrobulbar or peribulbar anaesthetics. However, lid malpositions are still seen under topical anaesthesia. Recent studies have implicated the lid speculum as a factor. Patients with narrower vertical palpebral apertures have been shown to develop postoperative ptosis more frequently, but the reason is unknown. This is the first study to determine the forces exerted by lid speculae over a range of palpebral apertures. METHODS: Mechanical testing was undertaken using a Bose 3200 materials testing machine. Tests were undertaken on four disposable and four reusable speculae. The force used to compress each speculum was compared over a range of displacements. A two-sample t-test was used to compare the stiffness of the two types of speculum. RESULTS: The stiffness of the reusable speculum was significantly greater than the disposable speculum (P=0.002). The stiffness of each speculum was greatest at the range of displacement corresponding to the narrower palpebral apertures. CONCLUSIONS: Different speculae exert significantly different forces on patients' eyelids during surgery. The patients who experience the greatest compression from the speculae are those with the smallest palpebral apertures. This may explain why these patients are more likely to develop postoperative lid malpositions.

Amantadine for dyskinesia in Parkinson's disease.

BACKGROUND: Abnormal involuntary movements known as dyskinesias are amongst the most disabling side-effects of levodopa therapy. It is thought that amantadine, an NMDA-receptor antagonist, may reduce dyskinesias in patients with Parkinson's disease without worsening Parkinsonian symptoms. OBJECTIVES: To compare the efficacy and safety of adjuvant amantadine therapy versus placebo in treating dyskinesia in patients with Parkinson's disease, already established on levodopa, and suffering from motor complications. SEARCH STRATEGY: Electronic searches of The Cochrane Controlled Trials Register (The Cochrane Library Issue 3, 2001), MEDLINE (1966-2001), EMBASE (1974-2001), SCISEARCH (1974-2001), BIOSIS (1993-2001), GEROLIT (1979-2001), OLDMEDLINE (1957-1965), LILACS (1982-2001), MedCarib (17th Century - 2001), PASCAL (1973-2001), JICST-EPLUS (1985-2001), RUSSMED (1973-2001), DISSERTATION ABSTRACTS (2000-2001), SIGLE (1980-2001), ISI-ISTP (1990-2001), Aslib Index to Theses (2001), Clinicaltrials.gov (2001), metaRegister of Controlled Trials (2001), NIDRR (2001) and NRR (2001) were conducted. Grey literature was hand searched and the reference lists of identified studies and reviews examined. The manufacturers of amantadine were contacted. SELECTION CRITERIA: Randomised controlled trials comparing amantadine with placebo in the treatment of dyskinesia in patients with a clinical diagnosis of idiopathic Parkinson's disease. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by NC and KD onto standardised forms and disagreements were resolved by discussion. MAIN RESULTS: Three randomised controlled trials were found comparing amantadine with placebo in the treatment of dyskinesia in patients with idiopathic Parkinson's disease. Three trials were excluded on the basis that they had no control group and a further three did not state whether they randomised the treatment that participants received. The included trials were double-blind cross-over studies involving a total of 53 patients. All three studies failed to present data from the first arm, instead presenting results as combined data from both treatment arms and both placebo arms. Two trials had no wash-out interval between the treatment periods. In view of the risk of a carry-over effect into the second arm, the results of these trials were not analysed. The final trial had a one week wash-out interval but only examined 11 participants. One study reported side-effects of amantadine in 8 of the 18 participants, including confusion and worsening of hallucinations. Another reported reversible edema of both feet in one of eleven participants. REVIEWER'S CONCLUSIONS: Due to lack of evidence it is impossible to determine whether amantadine is a safe and effective form of treatment for levodopa-induced dyskinesias in patients with Parkinson's disease.

Beta-blocker therapy for tremor in Parkinson's disease.

BACKGROUND: The tremor of Parkinson's disease can cause considerable disability for the individual concerned. Traditional antiparkinsonian therapies such as levodopa have only a minor effect on tremor. Beta-blockers are used to attenuate other forms of tremor such as Essential Tremor or the tremor associated with anxiety. It is thought that beta-blockers may be of use in controlling the tremor of Parkinson's disease. OBJECTIVES: To compare the efficacy and safety of adjuvant beta-blocker therapy against placebo for the treatment of tremor in patients with Parkinson's disease. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE, SCISEARCH, BIOSIS, GEROLIT, OLDMEDLINE, LILACS, MedCarib, PASCAL, JICST-EPLUS, RUSSMED, DISSERTATION ABSTRACTS, SIGLE, ISI-ISTP, Aslib Index to Theses, The Cochrane Controlled Trials Register, Clinicaltrials.gov, metaRegister of Controlled Trials, NIDRR, NRR and CENTRAL were conducted. Grey literature was hand searched and the reference lists of identified studies and reviews examined. The manufacturers of beta-blockers were contacted. SELECTION CRITERIA: Randomised controlled trials of adjuvant beta-blocker therapy versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by two of the authors onto standardised forms and disagreements were resolved by discussion. MAIN RESULTS: Four randomised controlled trials were found comparing beta-blocker therapy with placebo in patients with idiopathic Parkinson's disease. These were double-blind cross-over studies involving a total of 72 patients. Three studies did not present data from the first arm, instead presenting results as combined data from both treatment arms and both placebo arms. The risk of a carry-over effect into the second arm meant that these results were not analysed. The fourth study presented data from each arm. This was in the form of a mean total score for tremor for each group. Details of the baseline scores, the numbers of patients in each group and standard deviations were not provided, meaning that the magnitude and significance of any changes due to therapy could not be calculated. One study reported a substantial fall in heart rate in 14 of the 22 patients, with one patient withdrawing after his heart rate dropped to 56 beats per minute (baseline heart rate was not reported). REVIEWER'S CONCLUSIONS: In view of this lack of evidence, it is impossible to determine whether beta-blocker therapy is effective and safe for the treatment of tremor in Parkinson's disease. The high frequency of bradycardia in one trial raises some concerns about the prescription of beta-blockers to normotensive elderly patients but the study was too small for the true degree of risk to be calculated.

Amantadine in Parkinson's disease.

BACKGROUND: Although levodopa is the most common drug prescribed to relieve the symptoms of Parkinson's disease it is associated with motor and psychiatric side-effects. Consequently, interest has turned to alternative drugs with improved side-effect profiles to replace or augment levodopa. Amantadine, originally used as an antiviral drug, has been shown to improve the symptoms of Parkinson's disease. OBJECTIVES: To compare the efficacy and safety of amantadine therapy (monotherapy or adjuvant therapy) versus placebo in treating people with Parkinson's disease. SEARCH STRATEGY: Electronic searches of The Cochrane Controlled Trials Register (The Cochrane Library Issue 3, 2001), MEDLINE (1966-2001), EMBASE (1974-2001), SCISEARCH (1974-2001), BIOSIS (1993-2001), GEROLIT (1979-2001), OLDMEDLINE (1957-1965), LILACS (1982-2001), MedCarib (17th Century - 2001), PASCAL (1973-2001), JICST-EPLUS (1985-2001), RUSSMED (1973-2001), DISSERTATION ABSTRACTS (2000-2001), SIGLE (1980-2001), ISI-ISTP (1990-2001), Aslib Index to Theses (2001), Clinicaltrials.gov (2001), metaRegister of Controlled Trials (2001), NIDRR (2001) and NRR (2001) were conducted. Grey literature was hand searched and the reference lists of identified studies and reviews examined. The manufacturers of amantadine were contacted. SELECTION CRITERIA: Randomised controlled trials comparing amantadine with placebo in the treatment of patients with a clinical diagnosis of idiopathic Parkinson's disease. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by NC and KD onto standardised forms and disagreements were resolved by discussion. MAIN RESULTS: Six randomised controlled trials were found comparing amantadine monotherapy or adjuvant therapy with placebo in the treatment of idiopathic Parkinson's disease. Five examined amantadine as adjuvant therapy with optimal levels of levodopa or anticholinergics and one examined amantadine as an adjuvant therapy with minimum tolerated levels of anticholinergics or as a monotherapy. Five were double-blind cross-over studies and one was a double-blind parallel group study. In total they examined 215 patients. The parallel group study allowed the randomisation codes to be broken and allowed patients in the placebo group to then receive amantadine. This could have led to bias. One study did not present the results of the placebo arm of the trial, hence we could not determine the difference between the two treatment groups. Two cross-over studies presented the results of the combined data from both treatment and placebo arms. The risk of carry-over effect into the second arm meant that these results could not be analysed. The final two studies presented at least some of their data from the end of the first arm of the trials. However only means were given, without standard deviations, so we could not determine the statistical significance of any difference between the amantadine and placebo groups. Although the authors did report on the side-effects from amantadine (such as livido recticularis, dry mouth and blurred vision), they state that none of them were severe. REVIEWER'S CONCLUSIONS: A considerable amount of evidence on the effectiveness of amantadine has accrued from non-controlled trials, often in patients with Parkinsonian conditions other than idiopathic Parkinson's disease. However, rigorous analysis of the six randomised controlled trials of amantadine reveals insufficient evidence of its efficacy and safety in the treatment of idiopathic Parkinson's disease.

Living with chronic venous leg ulcers: a descriptive study of knowledge and functional health status.

A descriptive design was used to identify the functional health status and knowledge level of individuals living at home with chronic venous leg ulcers (N = 21). Limitations in physical function and vitality were moderate to severe, impacting on study participants' productive activities and activities of daily living. Severe to moderate pain was experienced by 19% of the participants. In addition, knowledge deficits were apparent regarding the cause and treatment of leg ulcers. Findings of this study suggest the importance of assessing these factors in addition to the wound when caring for individuals in the community with chronic venous leg ulcers.

A new and rapid method for the determination of nicarbazin residues in poultry feed, eggs and muscle tissue using supercritical fluid extraction and high performance liquid chromatography.

A simple and rapid method, using supercritical fluid extraction (SFE) with off-line high-performance liquid chromatography for the isolation and determination of nicarbazin, a popular broad-spectrum coccidiostatic drug used principally in poultry, is described. Results show good repeatability with a minimum quantification level of 0.4 microgram g-1 and mean 'spiked' recoveries of 98%, 100% and 99% using poultry feeds (n = 18), eggs (n = 28) and chicken tissue (n = 20), respectively. SFE using carbon dioxide is proposed as an alternative isolation method to the current Association of Official Analytical Chemists (AOAC) procedure which involves the use of large volumes of a harmful solvent (dimethylformamide) and requires a long tedious separation and clean-up regime (6 h) prior to its determination.

Outcomes after laser stapedotomy with and without preservation of the stapedius tendon.

Our goal was to investigate the postoperative differences in hearing between patients who had their stapedius tendon sacrificed and those whose stapedius tendon was preserved during laser stapes surgery for otosclerosis. To that end, we performed a retrospective review by mailing extensive questionnaires to patients who had been operated on between 1994 and 1997. We also performed routine and special audiometric testing to augment the subjective data. Seventy-nine of 124 questionnaires (64%) were returned. Of the respondents, 75 patients had undergone additional pre- and/or postoperative audiometric testing, including tests to evaluate "hearing in noise" and to determine the "uncomfortable loudness level" (dynamic range). We found no statistically significant differences between the two groups with respect to their subjective responses and their audiologic test results. The responses to the questionnaire indicated that in most cases, hearing was improved by stapes surgery. We conclude that the stapedius tendon should be preserved whenever possible during stapes surgery, provided that it does not jeopardize the exposure or outcome.

The role of the venous system in the abdominal flap of the rat.

The abdominal flap of the rat has become a popular model with investigators. Recently, researchers have been reporting survival of skin flaps with varying blood supplies. We studied the viability of skin flaps on a consistent model with varied blood supply. An 8 x 9 cm flap was raised in 40 male Sprague-Dawley rats. The viability of the flaps could be studied in 25 rats. The survival of a pedicled flap based on the left inferior epigastric artery and vein was compared with that of a pedicled flap with enhanced venous drainage. The survival of a venous flap based on the paired inferior epigastric veins and the paired long thoracic veins was compared with that of an arterialized venous flap. A composite graft was used as a control for all groups. A qualitatively improved survival was found in the pedicled venous-enhanced group (66 percent) compared with the pedicled flaps (56 percent) (p > 0.05). An improved survival was found in the arterialized venous flap (57 percent) compared with the venous flap (40 percent) (p < 0.05). All flaps had improved survival compared with the composite graft (0.6 percent) (p < 0.05).

Microvascular anastomoses. A comparative study of fibrinogen adhesive and interrupted suture techniques.

A modified sleeve technique was developed for making microsurgical anastomoses using a commercially produced fibrinogen adhesive called Tisseel. A controlled study was then carried out to compare the new fibrinogen adhesive anastomoses with conventional suture anastomoses in a bilateral groin flap model using 50 consecutive rabbits. Statistical analysis of the results indicated that flap survival rate and vascular patency rate were comparable for the two techniques. The fibrinogen adhesive anastomoses took less time to complete and, subjectively, were less difficult technically. The suture anastomoses were more versatile. Histologic studies revealed that the adhesive did not flow through the sleeve into the lumen, and that, although there was a brief inflammatory response associated with healing, this inflammation was very localized and did not involve the inner layers of the vessel wall or lumen. It was concluded that the new technique was a useful addition to techniques already available.

Advanced non-animal microsurgical exercises.

For the novice microsurgeon, suturing simple lines on a static model ill prepares them for the technically difficult live model that is to follow. A practice card was therefore designed to make the transition easier. The basic building block is rubber glove sutured to form a simple tube. From this point, progressive exercises are carried out. These are (1) simple suturing, (2) tube anastomosis, (3) end-to-end anastomosis, (4) end-to-side anastomosis, (5) side-to-side anastomosis, (6) inequality of diameters, and (7) free graft placement. Since the student is faced with problems that are challenging and progressively complex, a noticeable improvement is seen in their skills. These models introduce the student to planning and instrumentation that they would deal with in the clinical situation. Once the student has mastered these exercises, he/she is ready to advance to the rat model.

Investigation of the stability of medicinal additives in animal feedingstuffs to prepare reference feeds.

The stability of several medicinal additives in cattle, pig and poultry feeds has been monitored. The feeds were stored at various temperatures under different conditions; processes such as freeze-drying, gamma-irradiation and pelletization were also applied. The medicinal additives appeared to be more stable in the feeds stored at reduced temperatures and under conditions that totally exclude light. Processing of feeds and storage at elevated temperature appeared to reduce the content of the medicinal additives examined.

Hypothyroidism protects the brain during transient forebrain ischemia in gerbils.

The mechanisms by which brain cells die after brief episodes of cerebral ischemia are not fully understood. In certain brain regions this damage may not be apparent for days. Hypothyroidism is known to decrease cerebral metabolism. We postulated that this slowing in cerebral metabolism may be neuroprotective after transient cerebral ischemia. To test this hypothesis, a total of 10 gerbils had thyroidectomies performed 2 weeks prior to ischemia. Six gerbils served as euthyroid controls. All animals were exposed to 5 min of transient ischemia and sacrificed 7 days after the insult. Silver degeneration staining was used for histological evaluation. Hippocampal damage [subiculum (P < 0.001), CA1 (P = 0. < .001), CA3 (P < 0.05), and CA4 (P < 0.001)] was significantly less in the hypothyroid animals. There was also significantly less damage in the cerebral cortex (P < 0.05) and thalamus (P < 0.05) in the hypothyroid animals. The exact mechanism of this protection is not fully understood but could be secondary to a decrease in the metabolic activity, or a reduced generation of free radicals (as is seen with protection from ischemia in kidney and liver under hypothyroid conditions). Further studies are required in order to gain a better understanding of the protective effects of hypothyroidism on cerebral ischemia.

Competitive enzyme-linked immunosorbent assay for the determination of zinc bacitracin in animal feedingstuffs.

Traditionally, bioassay has been the chosen technique for the determination of bacitracin compounds in animal feedingstuffs. However, detection and determination of this antibiotic have given problems when it is present at low levels. A competitive enzyme-linked immunosorbent assay (ELISA) by which it is possible to detect both bacitracin and zinc bacitracin at levels as low as 1 mg kg-1 in animal feeds is described. The ELISA technique has been used in this laboratory to monitor samples from a drug stability storage trial for the presence of zinc bacitracin. In addition, individual polypeptide components of zinc bacitracin have been separated by high-performance liquid chromatography. Fractions were collected and tested by the ELISA technique to assess the response between individual components and the primary antibody. The response was compared with known microbiological activity.

Promontory testing in neurotologic diagnosis.

The ability of promontory testing (PT) to differentiate a retrocochlear from a cochlear lesion in a group of 88 patients having unilateral sensorineural hearing loss was assessed. Promontory stimulation was performed, using the Nucleus Promontory Stimulator (model Z10012, Cochlear Corporation, Melbourne, Australia), by placing a needle electrode transtympanically on the basal turn of the cochlea. Patients with measurable hearing gave inconsistent results. Patients who had undergone eighth nerve section or translabyrinthine removal of acoustic neuroma were used as controls. They had no perception of sound in response to electrical stimulation, and were unable to perform any part of the PT. Of nine patients with anacusis secondary to an acoustic neuroma, six were unable to perceive sound in response to electrical stimulation or perform any aspect of the PT. Of the three patients able to perceive sound, only one could perform the temporal difference limen (TDL) and gap detection (GAP) test. In patients with total deafness from other causes, 80 percent (24/30) were able to perceive sound with electrical stimulation, 46 percent (14/30) performed TDL, and 70 percent (21/30) performed the GAP tests. In patients with unilateral total deafness, promontory testing may aid in differentiating retrocochlear from cochlear lesions and help identify patients at risk for acoustic neuroma.

Bronchiectasis and rheumatoid arthritis: a clinical study.

OBJECTIVES: To examine the relation between rheumatoid arthritis (RA) and bronchiectasis (BR). METHODS: Disease activity, outcome, extra-articular manifestations, and laboratory features were compared in 32 patients with BR and RA (RA-BR group), 32 matched patients with RA without BR (RA group), and 31 patients with BR but without arthritis (BR group). RESULTS: In 30 of the 32 (94%) patients with RA-BR, BR preceded RA. There was no functional or radiological difference between the RA-BR and RA groups, and except for xerophthalmia, which was more common in patients with RA-BR than patients with RA, there was no difference in extra-articular or laboratory features. CONCLUSIONS: Bronchiectasis does not lead to a more aggressive disease course in RA and, despite the recognised association, BR is not an extra-articular manifestation of rheumatoid disease.

Microneurovascular free digital pad transfer in the dog.

By cadaver dissections, the fifth digit of the canine hind limb was determined to have a consistent neurovascular anatomy, and therefore be a suitable donor for an axial pattern digital pad flap. The defined digital pad flap was transferred to the region of an excised metacarpal pad by microneurovascular anastomoses in five operations on four dogs. One flap failure was considered to result from failure of the venous anastomosis. In all four successful transfers, cutaneous sensation was reestablished on average in 78 days. There was histologic evidence of nerve regeneration across the anastomosis in one dog at week 24. The transferred pads of three dogs monitored for 15 months underwent hypertrophic changes. There were no complications in two active dogs. In one dog, superficial ulceration of a region of the flap adjacent to the pad required surgical revision. This dog continued to show mild lameness after daily runs of 3 to 4 km.

Identification of medicinal additives in animal feedingstuffs by high-performance liquid chromatography.

A method is described for the detection of 25 drugs used as prophylactics or as growth promoters in commercial animal feedingstuffs. The sample was extracted with aqueous acetonitrile, the co-extractives were removed with a silica cartridge and the eluate was examined by high-performance liquid chromatography, using two columns and five mobile phases. Thirteen animal ++feedingstuffs containing different combinations of drugs were prepared and used to test the method.

Review of current and future analytical methods for the determination of mycotoxins.

Chemical methods of analysis for the extraction, clean-up and determination of aflatoxins from animal feedingstuffs and foods are described. The advantages and disadvantages of thin layer chromatography (t.l.c.) and high pressure liquid chromatography (h.p.l.c.) are discussed along with newer techniques such as immunoassay. Methods for other mycotoxins such as ochratoxin, patulin, and the trichothecenes are also included. Problems encountered during collaborative testing of these methods limit the reproducibility that can be achieved.