The effects of a prophylactic bolus of lidocaine in focal cerebral ischaemia

In order to determine the cerebral protective effects of an intravenous bolus of 5 mg.kg-1 of lidocaine, the left middle cerebral artery (MCA) was transorbitally occluded in 19 cats. Ten animals received the lidocaine bolus and nine a similar volume of saline immediately before MCA occlusion. Somatosensory evoked potentials (SEP) were recorded before and after the lidocaine bolus as well as continually after MCA occlusion. After six hours of vessel occlusion and without reperfusion, the animals were sacrificed and the brains fixed for histology. Prior to MCA occlusion, lidocaine caused a statistically significant (p less than 0.01) reduction in the amplitude of the major cortical component of the SEP (10 +/- 1.2 microV vs 6.0 +/- 1.3 microV). Latency was unchanged. In the lidocaine group, SEP's persisted in 40 per cent immediately following occlusion whereas they disappeared in all of the control animals (p less than 0.05). Gradual recovery occurred in both groups and there were no differences at the end of the experiment although the amplitudes tended to be greater in the lidocaine group. There were no statistically significant differences in the histological size or severity of the infarcts between the groups. Although infarct size was not reduced, transient sparing of the SEP suggests that further studies of lidocaine by continuous infusion in models of temporary focal cerebral ischaemia may be warranted.     

Andrology: Deleterious effects of khat addiction on semen parameters and sperm ultrastructure

The semen parameters and sperm ultrastructural morphology havebeen described in semen samples from two groups of Yemeni subjects.The first ‘exposed’ group comprised 65 khat addicts,while the second control group included 50 non-khat addict subjects.The mean age was 39.94 ± 13.85 and 35.72 ± 11.35years in the exposed and control groups respectively, withouta significant difference. The mean duration of khat addictionamong the addicts was 25.34 ± 12.96 years (range 6.00–48.00).Statistically significant differences were detected betweenthe semen parameters of the two groups. Such parameters, includingsemen volume, sperm count, sperm motility, motility index andpercentage of normal spermatozoa, were lower among addicts.Significant negative correlation was also found between theduration of khat consumption and all semen parameters (r rangedfrom –0.30 to –0.74). At the transmission electronmicroscopy level, a counting system was incorporated to comparethe numbers of normal spermatozoa with deformed and dead spermatozoain ultrathin plastic sections. The total mean percentage ofdeformed spermatozoa was {small tilde}65%. Different patternsof sperm deformation were demonstrated, and included both thehead and flagella in complete spermatozoa, aflagellate heads,headless flagella and multiple heads and flagella. Deformedheads showed aberrated nuclei with immature nuclear chromatinand polymorphic intranuclear inclusions; these were associatedwith acrosomal defects. The deformed flagella demonstrated numericaberrations of the axonemal 9 + 2 configuration and structuraldefects of their associated elements. Persistent cytoplasmicdroplets were observed frequently. This study has shown forthe first time the deleterious effects of khat addiction onsemen parameters in general and sperm morphology in particularof all addicts, especially those who have consumed khat forlonger periods of time.     

Prognostic significance of circulating immune complexes in cancer patients.

Circulating immune complexes (CIC) were estimated in 100 cancer patients and 25 healthy control volunteers by means of the polyethylene glycol (PEG) precipitation test and latex agglutination inhibition (LAI) test. Pathological levels of CIC were found in 47% of the patients by PEG precipitation test and in 59% of the patients by LAI test; both tests were positive in 33% of the patients. Consequently, the use of the two assays resulted in 73% seropositivity for CIC. The PEG precipitation test detects antigen-antibody complexes formed in the ratio of 2:1 (Ag2Ab), while the LAI test could detect immune complexes formed over an extended range of antigen-antibody ratio including complexes as small as 8S. CIC values were significantly higher by combined assays (P less than 0.001) as compared to individual assays (P less than 0.01) when compared with the control group. It was found that 75% of post-operative follow-up patients became seronegative for CIC in the combined assays, whereas the 25% of post-operative patients who remained seropositive for CIC showed recurrence within three months after surgery. Immune-complex deposition was demonstrated on malignant cells in vitro by direct immunofluorescence studies in 73.3% of patients, while 60% of patients revealed complement-fixing antigen-antibody complexes. It was found that 20% of patients showing positive immunofluorescence with anti-C3-antisera had decreased levels of CIC. Complement-mediated cytotoxic injury results in reduction of tumor cell mass and subsequent decrease in CIC. Necrotizing and leucocytoclastic vasculitis in the tumor mass was initiated by raised CIC levels in vivo in 71% of patients. Necrosis of malignant tumors was seen in 58% of patients, and hemorrhage in 36% of patients. These changes were considered to be an aftermath of immuno-complex vasculitis initiated by CIC.     

Effect of digital massage on intraocular pressure and ocular and optic nerve blood flow

The effect of digital massage on intraocular pressure and ocular and optic nerve blood flow was studied in anaesthetized rabbits. Digital massage was performed for 15 min, with pressure release for 15 seconds after each 45 seconds of massage. Blood flow was measured in the iris, ciliary processes, choroid, retina, and optic nerve using (85Sr)-labelled microspheres. Blood flow was determined during massage, 2 min after, or 15 min after massage. Intraocular pressure was measured before, immediately after, and in one group, 15 min after massage. Immediately after digital massage, intraocular pressure was significantly lower, but 15 min after it was not significantly reduced. At both 2 min and 15 min after digital massage, compared to during massage, blood flow was significantly higher in all tissues studied.     

Management of allergic problems in primary care: time for a rethink?

Allergic diseases affect 20-30% of the UK population and when severe are associated with considerable morbidity and occasional mortality. Initiatives to improve allergy services in the UK have been led by consultant allergists and have focussed on increasing the number of hospital training posts to improve access to specialist services. A high profile campaign to raise awareness of the lack of allergy services has so far failed to generate further training numbers for allergy as a single specialty. Although the campaign to improve tertiary allergy services continues, most mild or moderate allergy symptoms (e.g. hayfever, allergic asthma, urticaria and some food allergy problems), can be managed successfully in primary care with appropriate interest and training. Despite the high and increasing numbers of patients with allergy and the ease with which the majority of symptoms can be controlled, many doctors in primary care are reluctant to take a more proactive approach to managing allergic conditions. This appears to be due to concerns about overburdening an already busy service, but may also be due to recommendations from allergy specialists which have implied that high quality allergy care is not possible without identification of specific allergic triggers using skin prick tests or blood tests. In reality, symptoms can usually be controlled using pharmacotherapy, although a working knowledge of the appropriate guidelines is helpful. In this paper, we propose minimum levels of knowledge for all practitioners in order to raise the standards of primary care allergy management, and provide recommendations for training for those wishing to manage successfully more difficult allergy cases and allergy diagnosis.     

Spontaneous cerebrospinal fluid rhinorrhoea due to temporosphenoidal encephalocele.

A 57-year old man was referred to our hospital with spontaneous cerebrospinal fluid (CSF) rhinorrhoea of 6 years duration. He had an episode of meningitis 2 months previously. CT cisternography and cranial MRI revealed a defect in the lateral wall of the sphenoid sinus, with an anteromedial temporosphenoidal encephalocele. Surgery was performed transcranially through a pterional approach. The temporal encephalocele was amputated, the sphenoid sinus obliterated and the dural defect repaired. Lumbar drainage was used for 5 days after surgery. Spontaneous CSF rhinorrhoea is only infrequently due to temporal encephalocele. Anteromedial temporosphenoidal encephaloceles are the least common type of temporal encephalocele, with only 12 reported in the literature.     

Alterations in ocular and optic nerve blood flow during intraocular surgery in aspirin pretreated rabbits

The effect of intraocular surgery on ocular and optic nerve blood flow was determined in rabbits either untreated or pretreated with aspirin. Surgery was either extracapsular lens extraction through a 100 degrees corneal incision or a sham-operation in which a 45 degrees corneal incision was performed and the lens left in place. In both cases, the incisions were not sutured and the intraocular pressure remained zero for one hour. A (85Sr) radioactive microsphere technique was used to measure blood flow in the iris, scraped ciliary processes, retina, choroid, and optic nerve. In rabbits not receiving aspirin pretreatment, blood flow was statistically increased in all portions of the eye, except the retina and optic nerve, studied for sham-operated eyes, and in the iris and optic nerve in the lens extraction group. In rabbits pretreated with aspirin, blood flow remained at normal levels. These results are consistent with the hypothesis that prostaglandins released during ocular surgery cause increased ocular tissue blood flow.