Nerve anastomosis with glue: comparative histologic study of fibrin and cyanoacrylate glue

The authors report the results of a comparative experimental nerve study, using a biologic tissue glue (fibrin) and a synthetic glue (2-cyanoacrylate) in a rat model. A tension-free repair is necessary with the use of fibrin glue, or gapping may occur, thus limiting the use of the agent in promoting re-neurotization. In addition, the human origin of fibrin and thrombin allow for the possibility of viral transmission. The aim of the study was to verify if the synthetic glue is a viable alternative, or whether it causes cellular and tissue lesions. Their main finding was that the cyanoacrylate causes a foreign-body inflammatory reaction and retractile fibrosis, often reducing the nerve diameter up to two-thirds. Cyanoacrylate glue is thus not recommended for peripheral nerve repair.     

Comparison between 1.5% lidocaine with adrenaline and 1.5% plain mepivacaine in axillary brachial plexus block]

OBJECTIVES: To evaluate the distribution of sensory blockade, the onset time and the duration of the axillary plexus block obtained after the administration of 40 mL of 1.5% lignocaine with adrenaline or 40 mL of plain 1.5% mepivacaine. STUDY DESIGN: Prospective, randomised, comparative, double blind study. PATIENTS AND METHODS: One hundred and fifty five patients undergoing hand surgery were randomised into two groups: in group L, 73 patients were given 1.5% lignocaine with 1/200,000 adrenaline and in group M, 82 patients received 1.5% mepivacaine. The entire volume was injected on the first evoked motor activity obtained for a current less than 0.5 mA. Sensory and motor block of each of the four major nerves of the hand and forearm were assessed using light touch and motor strength respectively. The block was considered complete when all nerves were anaesthetised (median, radial, musculocutaneous and ulnar). RESULTS: The percentage of complete sensitive blockade was 22% in group L and 24% in group M. Complete motor blockade was respectively 27% in group L and 40% in group M. The median time required to obtain a complete sensory blockade was 18 min for both group. The median time required to obtain a complete motor blockade was 17 min in-group L and 16 min in-group M. The duration of the sensory blockade was not different for both groups (i.e., 255 +/- 76 min versus 231 +/- 70 min in group L and M respectively. The duration of the motor blockade was longer in group L compared to group M (199 +/- 64 min versus 231 +/- 74 min respectively, p < 0.05). CONCLUSION: Following axillary plexus block, 1.5% mepivacaine improves neither the extension nor the duration of sensory blockade achieved by 1.5% lignocaine with adrenaline.     

Qualitative research methodology in the exploration of patients' perceptions of participating in a genetic research program

The success of genetic research studies depend on patients' willingness to participate. It is thus important to explore the attitudes of individuals that participate in such studies. This study used qualitative methods to explore how individuals with inherited retinal degenerative disorders (RDD) perceived participating in genetic research and subsequently receiving mutation results. Individual interviews were conducted with all the individuals in the Cape Town Metropolitan area who had received mutation results after participating in a genetic research program (4 individuals). Although experiences differed significantly, the study revealed that the participants had positive attitudes towards participating in the RDD research program. This study illustrates the importance of using qualitative methods in ophthalmic populations to explore important issues.     

Bilateral periocular psoriasis: an initial manifestation of acute generalized pustular psoriasis with coexistent Sjögren's syndrome

A 21‐year‐old febrile lady presented to the emergency service with severe lid oedema, conjunctivitis, dry mouth and abdominal skin rash. Over 5 days, she developed silvery scales and pustules on the lids, and generalized pustules on an erythematous base. Multiple focal sterile corneal infiltrates were seen. Haematological investigations and a skin biopsy were done as the consulting dermatologist suspected acute generalized pustular psoriasis. In addition, secondary Sjögren's syndrome was diagnosed since she had keratoconjunctivitis sicca, xerostomia, raised erythrocyte sedimentation rate and positive antinuclear antibodies. The presence of microabscesses in the epidermis on skin biopsy confirmed the diagnosis of pustular psoriasis. With oral methotrexate 7.5 mg weekly and topical corticosteroids, the acute condition gradually resolved; however, the keratoconjunctivitis sicca is persisting. Secondary Sjögren's syndrome associated with acute generalized pustular psoriasis and ocular psoriasis is extremely rare. Awareness of the ocular and dermatological features of these two conditions would result in earlier diagnosis and institution of appropriate treatment.     

The effects of perinatal hypoxia on the behavioral,neurochemical, and neurohistological toxicity of the metabolic inhibitor 3-nitropropionic acid

3-nitropropionic acid (3-NPA) neurotoxicity and long-term effects of perinatal hypoxia were evaluated in 18 adult rats. Hypoxia-insulted (I) and noninsulted (NI) rats were delivered by cesarean section. Hypoxic insult was effected by submerging dissected uterine horns in warmed saline for 15 min. NI rats were delivered from the adjacent nonsubmerged horns. At postnatal day 90, I and NI rats were trained to perform tasks thought to measure behaviors dependent upon aspects of time estimation (TE), motivation, and learning. At 12 months of age, rats were injected i.p. with escalating doses of 3-NPA (5 mg/kg/day to a maximum of 30 mg/kg/day) immediately after each test session and sacrificed at the end of treatment. Additional male rats were used as untreated controls. Although 3-NPA produced a dose-dependent impairment of performance in each task, the effects were qualitatively similar for each group. A significant difference between I and NI rats was, however, observed in the TE task where NI rats completed less of the task at high doses of 3-NPA compared to I rats. Compared to untreated controls, dopamine concentrations were decreased in caudate nucleus of both I and NI rats after 3-NPA. Specific areas most frequently damaged included cerebral cortex, hippocampal subfield CA1, thalamus, caudate nucleus, and the cerebellum. Lesions usually were less extensive in the I rather than NI members of a littermate pair, suggesting a possible protective effect of perinatal hypoxia against subsequent 3-NPA neurotoxicity.     

Ultrasound detection of spontaneous hepato-cellular carcinomas in X/myc bitransgenic mice.

AIMS: To evaluate trans-abdominal ultrasound for the detection of Hepatocellular carcinoma (HCC) in a bitrasgenic murine (X/myc) model using a commercially available high-frequency ultrasound unit. METHODS: Sixty-one female animals were included in this study. These animals were submitted to a single ultrasound examination of the liver under general anesthesia (isoflurane), and then euthanized. Results of ultrasound were compared with necropsy and histopathology. RESULTS: The lesions demonstrated a fairly consistent aspect (oval- or round-shaped, well-defined hypoechoic homogeneous lesions), and lesions as small as 2 mm were identified. For detection of hepatic nodules per mouse the sensitivity was 75%, the specificity was 100% and the accuracy was 88.5%. For detection of hepatic focal lesions per lesions the overall sensitivity was 60%, the specificity was 97%, and the accuracy was 75.9%. Contrast-enhanced harmonic ultrasound imaging did not improve the identification of the lesions in our experimental conditions. CONCLUSION: High-frequency ultrasound appears to be an efficient tool allowing new possibilities to use this animal model and evaluate new therapies in longitudinal studies, which are much more powerful.