The emerging role of heterodimerisation and interacting proteins in ghrelin receptor function

Ghrelin is a peptide hormone secreted primarily by the stomach that acts upon the growth hormone secretagogue receptor (GHSR1), a G protein-coupled receptor whose functions include growth hormone secretion, appetite regulation, energy expenditure, regulation of adiposity, and insulin release. Following the discovery that GHSR1a stimulates food intake, receptor antagonists were developed as potential therapies to regulate appetite. However, despite reductions in signalling, the desired effects on appetite were absent. Studies in the past 15 years have demonstrated GHSR1a can interact with other transmembrane proteins, either by direct binding (i.e. heteromerisation) or via signalling cross-talk. These interactions have various effects on GHSR1a signalling including preferential coupling to one pathway (i.e. biased signalling), coupling to a unique G protein (G protein switching), suppression of GHSR1a signalling, and enhancement of signalling by both receptors. While many of these interactions have been shown in cells overexpressing the proteins of interest and remain to be verified in tissues, substantial evidence exists showing that GHSR1a and the dopamine receptor D1 (DRD1) form heteromers, which promote synaptic plasticity and formation of hippocampal memory. Additionally, a reduction in GHSR1a-DRD1 complexes in favour of establishment of GHSR1a-Aβ complexes correlates with Alzheimer's disease, indicating that GHSR1a heteromers may have pathological functions. Herein, we summarise the evidence published to date describing interactions between GHSR1a and transmembrane proteins, discuss the experimental strengths and limitations of these studies, describe the physiological evidence for each interaction, and address their potential as novel drug targets for appetite regulation, Alzheimer's disease, insulin secretion, and inflammation.

In-hospital mortality from abdominal aortic surgery in Great Britain and Ireland: Vascular Anaesthesia Society audit

Background

The mortality rate associated with elective aortic aneurysm repair is widely assumed to be in the region of 5 per cent. This figure does not take into consideration the effect of pre-existing risk factors. The Vascular Anaesthesia Society of Great Britain and Ireland conducted a large audit to estimate the in-hospital mortality rate associated with non-emergency infrarenal aortic surgery throughout the British Isles, and to determine the influence of risk factors on mortality rate.

Methods

This was a multicentre, prospective audit of 177 hospitals throughout the UK and Ireland. Data were collected by questionnaire to include all patients undergoing elective or urgent surgery for infrarenal abdominal aortic aneurysm or aortoiliac occlusive disease over 4 months.

Results

Nine hundred and thirty-three patients were recruited into the audit. The overall mortality rate was 7·3 per cent. Factors increasing the risk of death by up to fivefold included age over 74 years, urgent surgery, operation for occlusive disease, limited exercise capacity, a history of severe angina or cardiac failure, the presence of ventricular ectopics and abnormalities suggesting ischaemic heart disease on electrocardiography.

Conclusion

Although the in-hospital mortality rate was similar to previously published figures, the rate increased considerably when commonly encountered risk factors were present.

Rationale for the observed COX-2/COX-1 selectivity of celecoxib from Monte Carlo simulations

Computational studies have yielded an analysis of the contributions to the free energy difference between the binding of celecoxib to COX-1 and to COX-2. The energetic and structural results point to the Ile to Val mutation at residue 523 as the key contributor to COX-2 selectivity; unfavorable steric contact between a sulfonamide oxygen and the delta methyl group of Ile523 destabilizes the complex with COX-1. The His to Arg change at residue 513 is less significant.

Regulation of serotonin release in the lateral septum and striatum by corticotropin-releasing factor

The serotonergic dorsal raphé nucleus (DRN) is innervated by corticotropin-releasing factor (CRF)-immunoreactive fibers and contains CRF receptor-binding sites, suggesting that endogenous CRF regulates this system. The present study examined the possibility that CRF in the DRN regulates the release of serotonin (5-HT) in forebrain terminal regions. Intracerebroventricular administration of CRF produced a bimodal effect on extracellular levels of 5-HT in the lateral septum. Doses of 0.3 and 1.0 microg decreased extracellular 5-HT levels, whereas both a higher (3.0 microg) and a lower (0.1 microg) dose had no effect. The reduction of extracellular 5-HT in the lateral septum by CRF (0.3 microg, i.c.v.) was blocked by pretreatment with the CRF receptor antagonist d-PheCRF(12-41) (3.0 microg, i.c.v.). Direct administration of CRF (30 ng) into the DRN reduced extracellular 5-HT levels in the lateral septum and the striatum. Furthermore, injection of d-PheCRF(12-41) (10 ng) into the DRN before ventricular administration of CRF (0.3 microg, i.c.v.) blocked the decrease in extracellular 5-HT in both the lateral septum and striatum. Taken together, these data support the hypothesis that CRF may modulate 5-HT release in terminal regions via its effects at the level of the DRN. This modulation supports a potential interaction between CRF and 5-HT in stress-related psychiatric disorders in which both systems have been implicated.

Lamotrigine monotherapy in children

The effectiveness of lamotrigine as a monotherapeutic agent for a variety of pediatric epilepsies was reviewed retrospectively. Children were categorized as having focal vs generalized epilepsy and according to whether they were antiepileptic drug naive or drug exposed. Data collected included dosages, side effects, length of follow-up, number of prior drugs, and treatment response. Treatment was considered successful if the patient was seizure free for 6 months or more. Eighty-three children were identified (average age = 8.7 years); 43 had focal epilepsy, 32 had generalized epilepsy, and eight were not classified. Twenty-nine patients were classified as having specific syndromes. Fourteen patients were drug naive. The median follow-up period was 8 months (mean = 8.5). Overall, 45% were seizure free, 44% with focal epilepsy and 36% with generalized epilepsy. All children with juvenile myoclonic epilepsy and benign rolandic epilepsy of childhood were seizure free, although not all had been treated for at least 6 months. One third of drug-naive patients were seizure free. Rash was the most common side effect and was reported in five patients (6%); two patients discontinued the drug. None had Stevens-Johnson syndrome. One quarter of children experienced nonquantifiable improvements, namely increased alertness and improved behavior regardless of seizure control. Lamotrigine is effective as a monotherapeutic agent in children for both focal and generalized epilepsies. Side effects are relatively uncommon. Lamotrigine may be an effective firstline agent.

Multiple cutaneous immunocytoma with secondary anetoderma: a report of two cases

We describe two men with multiple erythematous dermal nodules which were clinically and histologically consistent with a diagnosis of primary cutaneous immunocytoma. Both patients exhibited the very unusual feature of secondary anetoderma occurring in spontaneously resolving lesions. There is one previous report of anetoderma in association with a plasmacytoma. The pathogenesis remains unknown but release of cytokines such as interleukin-6 may be implicated.

The hyaluronan receptor RHAMM in noradrenergic fibers contributes to axon growth capacity of locus coeruleus neurons in an intraocular transplant model

The hyaluronan receptor for hyaluronic acid-mediated motility (RHAMM) plays a role in cell migration and motility in many systems. Recent observations on the involvement of RHAMM in neurite motility in vitro suggest that it might also be important in axon outgrowth in situ. This was addressed directly by investigating both RHAMM expression in the rat CNS and the ability of anti-RHAMM reagents to interfere with tissue growth and axon outgrowth in intraocular brainstem transplants. By western blotting, anti-RHAMM antibody detected a RHAMM isoform of 75,000 mol. wt in both whole brain homogenate and synaptosome preparations, and a 65,000 mol. wt isoform in synaptosomes. Immunofluorescence of adult brain sections revealed RHAMM-like immunoreactivity in varicose fibers that were also positive for the noradrenergic marker dopamine-beta-hydroxylase. Not all noradrenergic fibers contained RHAMM, nor was RHAMM detected in other monoaminergic fiber types. Lesions of noradrenergic fiber systems with beta-halobenzylamine-N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) eliminated RHAMM-positive fibers, but noradrenergic axons that sprouted extensively after this treatment were strongly RHAMM-positive. To assess RHAMM's role in fiber outgrowth, fetal brainstem tissue containing noradrenergic neurons was grafted into the anterior chamber of the eye. Treatment of grafts with anti-RHAMM antibody caused significant inhibition of tissue growth and axon outgrowth, as did a peptide corresponding to a hyaluronan binding domain of RHAMM. These agents had no such effects on transplants containing serotonergic and dopaminergic neurons. These results suggest that RHAMM, an extracellular matrix receptor previously shown to contribute to migratory and contact behavior of cells, may also be important in the growth and/or regenerative capacity of central noradrenergic fibers originating from the locus coeruleus.

Effects of corticotropin-releasing factor on brain serotonergic activity

The serotonergic dorsal raphe nucleus is innervated by corticotropin-releasing factor (CRF) and expresses CRF receptors, suggesting that endogenous CRF impacts on this system. The present study characterized interactions between CRF and the dorsal raphe serotonin (5-HT) system. The effects of intracerebroventricularly (i.c.v.) administered CRF on microdialysate concentrations of 5-HT in the lateral striatum of freely moving rats were determined. CRF had biphasic effects, with 0.1 and 0.3 microgram decreasing, and 3.0 micrograms increasing 5-HT dialysate concentrations. i.c.v. administration of CRF inhibited neuronal activity of the majority of dorsal raphe neurons at both low (0.3 microgram) and high (3 micrograms) doses. Likewise, intraraphe administration of CRF (0.3 and 1.0 ng) had predominantly inhibitory effects on discharge rate. Together, these results suggest that CRF is positioned to regulate the function of the dorsal raphe serotonergic system via actions within the cell body region. This regulation may play a role in stress-related psychiatric disorders in which 5-HT has been implicated.

Induction of mutagenic DNA damage in human fibroblasts after exposure to artificial tanning lamps

There is increasing concern about the adverse health effects associated with the use of sunbeds, particularly with respect to skin photocarcinogenesis. The induction of mutagenic DNA damage is a prerequisite for the development of skin tumours, and it is well established that direct types of damage such as cyclobutane pyrimidine dimers (CPDs) give rise to mutations in tumour suppressor genes and oncogenes. In addition, ultraviolet radiation may induce indirect types of DNA damage, including oxidative products, which are also potentially mutagenic. By using specific DNA repair enzymes (T4 endonuclease V and endonuclease III) and the comet assay we have been able to detect the induction of CPDs, oxidized or hydrated pyrimidine bases and single-strand breaks in cultured human fibroblasts (MRC-5) after exposure for between 15 s and 20 min on two different commercial sunbeds containing Philips 'Performance' 100W-R or Philips TL80W/10R lamps. The ratio of endonuclease III to T4 endonuclease V sensitive sites varied substantially between the two lamps and was 3.3% and 18%, respectively. The sunbed containing the 'Performance' 100W-R lamps was as potent at inducing CPDs as was natural sunlight in fine weather. These results establish that commercial tanning lamps produce the types of DNA damage associated with photocarcinogenesis in human cells, and complement epidemiological evidence indicating the potential risk of using sunbeds.

Effects of GDNF on fetal septal forebrain transplants in oculo

Glial cell line-derived neurotrophic factor (GDNF) is a member of the TGF-beta superfamily of growth factors with marked neurotrophic activity on midbrain dopaminergic neurons. To investigate whether this trophic activity is shared by central cholinergic neurons, we investigated the effects of GDNF treatment during development of the medial septal area in rats. Adult Fischer 344 rats received intraocular transplants of fetal septal forebrain tissue (embryonic Day 17) which was preincubated for 20 min with either GDNF or vehicle. The two treatment groups subsequently received weekly intraocular injections of either GDNF (0.5 microgram in 5 microliters/injection) or vehicle for 6 weeks following transplantation. Transplants treated with GDNF grew twice as large as control grafts treated with vehicle. Immunohistochemical evaluations of the transplants revealed that there was no difference between the two groups in terms of acetylcholinesterase or low affinity neurotrophin receptor (p75) staining. In contrast, a significant increment in the number of GABA-ergic neurons was observed in transplants that received GDNF, as compared to vehicle-treated grafts. The overall number of neurons within the transplanted tissue was also elevated in the experimental group. There was no difference between the two groups in the distribution or density of astrocytes in the grafted tissue, as evidenced by immunohistochemistry with antibodies directed against glial fibrillary acidic protein. These results indicate that basal forebrain GABA-ergic neurons may be dependent on GDNF for their survival and/or for GABA synthesis, but that the cholinergic neurons in this area appear to be unaffected by GDNF administration during development.

Tyrosine hydroxylase in the cerebral ganglia of the American cockroach (Periplaneta americana L.): an immunohistochemical study

We have investigated the distribution of tyrosine-hydroxylase-like immunoreactivity in the cerebral ganglia of the American cockroach, Periplaneta americana. Groups of tyrosine-hydroxylase-immunoreactive cell bodies occur in various parts of the three regions of the cerebral ganglia. In the protocerebrum, single large neurons or small groups of neurons are located in the lateral neuropil, adjacent to the calyces, and in the dorsal portion of the pars intercerebralis. Small scattered cell bodies are found in the outer layers of the optic lobe, and clusters of larger cell bodies can be found in the deutocerebrum, medial and lateral to the antennal glomeruli. Thick bundles of tyrosine-hydroxylase-positive nerve fibers traverse the neuropil in the proto- and deutocerebrum and innervate the glomerular and the non-glomerular neuropil with fine varicose terminals. Dense terminal patterns are present in the medulla and lobula of the optic lobe, the pars intercerebralis, the medial tritocerebrum, and the area surrounding the antennal glomeruli, the central body and the mushroom bodies. The pattern of tyrosine-hydroxylase-like immunoreactivity is similar to that previously described for catecholaminergic neurons, but it is distinctly different from the distribution of histaminergic and serotonergic neurons.

Successful surgical treatment of severe pretibial myxoedema

We report a 46-year-old man with severe and long-standing pretibial myxoedema, who responded well to local surgical treatment. This improvement has been maintained over a 12-month period, perhaps because of concomitant treatment with octreotide.

Primary systemic amyloid with nail dystrophy

We report a patient with the classical cutaneous findings of primary systemic amyloidosis, due to myeloma. He had developed a nail dystrophy, which is a recognized, but rare, feature in systemic amyloid.

Hypothalamic tissue stimulates hippocampal pyramidal neuron survival during development: evidence from intraocular double transplants

The present study was undertaken to evaluate innervation and possible growth promotion by posterior hypothalamic tissue on different areas that are, or are not, interactive with this brain region during development. Posterolateral hypothalamus was dissected from embryonic day 17 rat fetuses, and inserted into the anterior chamber of the eye of adult rat hosts. Two weeks postgrafting, a second transplant consisting of either fetal hippocampal, cerebellar, or lung tissue was placed adjacent to the first graft. Growth of the intraocular double transplants was monitored weekly by measurements through the cornea. Fetal hippocampal tissue grew significantly larger when placed together with a hypothalamic graft, as compared to single hippocampal transplants. Cerebellar or lung tissue growth was not stimulated by a hypothalamic cograft. Pyramidal neuron cell counts demonstrated a significantly higher final number of these neurons in growth-stimulated hippocampal grafts, as compared to non-stimulated single hippocampal grafts. Immunohistochemistry with antibodies directed against histamine or histidine decarboxylase revealed that hippocampal transplants received the most dense histaminergic innervation. Cerebellar transplants contained occasional histaminergic neurites, and lung tissue never exhibited any histaminergic innervation from the adjacent hypothalamic graft. Taken together, these results demonstrate a growth-promoting effect of posterior hypothalamic tissue on developing hippocampal tissue, as well as target specificity of histaminergic innervation patterns.

Technetium 99mTc-HMPAO SPECT in children and adolescents with neurologic disorders

We evaluated regional cerebral blood flow with technetium 99mTc hexamethylpropyleneamineoxime single photon emission computed tomography (SPECT) in 20 children and adolescents with neurologic dysfunction of varied etiology and abnormal electroencephalograms (EEGs). All patients were also examined with computed tomography (CT) and magnetic resonance imaging (MRI). Abnormal perfusion was found in 17 (85%) of 20 SPECT scans. Abnormal CT or MRI scans were noted in nine (45%) and in 10 (50%) of 20 cases, respectively. In eight (73%) of 11 cases with normal CT scans and in seven (70%) of 10 with normal MRI scans, the SPECT scan was abnormal. Abnormal regional cerebral blood flow on SPECT scans correlated better with EEG abnormalities than with neurologic examination or CT or MRI scan findings. We conclude that in children and adolescents with a spectrum of neurologic diseases and abnormal EEGs, abnormalities of brain structure or function are more likely to be documented by SPECT than by CT or MRI scans. SPECT findings correlate well with the location and type of EEG abnormality.

Plane xanthomatosis with chronic lymphatic leukaemia

A case of plane xanthomatosis in a 67-year-old woman, suffering from chronic lymphatic leukaemia, who developed asymptomatic yellow plaques on the neck, upper arms and chest is reported. Histology was suggestive of xanthelasma. Development of plane xanthomata has been reported in association with various haematological malignancies and with benign monoclonal gammopathies, but not previously with chronic lymphatic leukaemia.

The tissue distribution of factor XIIIa positive cells

Factor XIIIa has previously been used to identify a subgroup of dermal dendritic cells which co-express class II MHC antigens, intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1), leading to the suggestion that they play a central role in skin immune responses. To examine whether these cells may also be important constituents of other organs we have performed an immunohistochemical survey of normal tissue to identify the distribution of this factor XIIIa positive subgroup of dendritic cells in humans. Routine tissue sections from a range of organs were assayed for factor XIIIa expression using a standard peroxidase-antiperoxidase (PAP) immunolabelling technique. Dendritic, factor XIIIa positive cells were observed in all tissues studied, but were most numerous in skin and mucosal tissues (gastrointestinal tract, bladder). They were also observed associated with epithelial structures in lung and kidney, but were only rarely observed in liver, thyroid, testis and spleen. The distinctive distribution of these cells is consistent with an important role for them in immune responses at those sites.

Changes in cardiac index and estimated systemic vascular resistance during induction of anaesthesia with thiopentone, methohexitone, propofol and etomidate

Changes in cardiac index (CI) and estimated systemic vascular resistance (ESVR) were assessed non-invasively using pulsed Doppler ultrasound during induction of anaesthesia. Ninety-six ASA I patients were allocated randomly to one of four groups to receive alfentanil 8 micrograms kg-1 followed by a dose of thiopentone, methohexitone, propofol or etomidate sufficient to obtund the eyelash reflex. CI increased significantly by 8% 1 min after administration of both methohexitone (P < 0.05) and propofol (P < 0.05), returning to pre-induction values thereafter. CI increased after thiopentone but the increase was not statistically significant. There was a significant decrease in CI of 16% after induction with etomidate (P < 0.001). ESVR decreased significantly from pre-induction values by 18% after methohexitone (P < 0.001) and 23% after propofol (P < 0.001). ESVR in the thiopentone group decreased, but this was not statistically significant. ESVR increased significantly by 12% 1 min after induction of anaesthesia with etomidate (P < 0.05) and then decreased towards pre-induction values. The results suggest that the cardiostability of etomidate may not be as complete in all groups of patients as previous studies have suggested.

Molecular cloning and nucleotide sequence analysis of the gene encoding the immunoreactive Brucella abortus Hsp60 protein, BA60K

A recombinant 60 kDa Brucella abortus protein expressed in Escherichia coli was recognized in immunoblots by sera from mice experimentally infected with B. abortus and a dog experimentally infected with B. canis. Sera from humans and dogs with naturally acquired brucellosis also recognized this protein, which was designated BA60K. The gene encoding BA60K was localized within an 18 kb B. abortus genomic fragment and its direction of transcription determined by subcloning and maxicell analysis of selected restriction fragments. The nucleotide sequence of 1800 bases encompassing the predicted gene location was determined, revealing an open reading frame encoding a protein of 546 amino acids (predicted relative molecular mass of 57515). Solid phase micro-sequencing of BA60K eluted from two-dimensional polyacrylamide gels confirmed the predicted amino acid sequence. Comparison of the predicted amino acid sequence of BA60K with a protein sequence database revealed that BA60K shares 67.9% identity with the GroEL protein of E. coli, a member of the Hsp60 family of chaperonins. The immunodominant Hsp60 homologs from Legionella pneumophila, Chlamydia trachomatis and Mycobacterium tuberculosis were also found to share greater than 59% amino acid sequence identity with the BA60K protein. The identification of BA60K as a member of the Hsp60 family of chaperonins supports its role in stimulating a prominent host immune response during the course of Brucella infections. It also indicates that BA60K is an important candidate for studies aimed at identifying the antigens responsible for eliciting the protective immune response to brucellosis.

Extending epidural blockade for emergency caesarean section Evaluation of 2% lignocaine with adrenaline

Pre-existing epidural analgesia was rapidly extended in 36 consecutive patients presenting for emergency caesarean section by using 20 ml of 2% lignocaine + 1/200,000 adrenaline freshly prepared given by slow bolus injection. Despite a wide range of initial analgesic sensory levels the technique produced blocks that were dense with adequate anaesthesia for surgery in all patients within 12.5 min. The plasma local anaesthetic concentrations were well below the toxic range. Neonatal condition was good.

Breslow thickness of cutaneous malignant melanoma in paraffin wax and frozen sections

Breslow tumour thickness was measured in frozen and paraffin wax sections from 21 excision biopsies of cutaneous malignant melanomas by two observers. There was no consistent variation between frozen and paraffin wax sections, with recorded differences ranging from +0.3 mm to -0.2 mm. Interobserver differences ranged from +0.4 mm to -0.2 mm. The interobserver variations exceeded the intraobserver variations, but neither were significant. These findings show conclusively that, when using high quality frozen sections, there is no significant difference between Breslow thickness measured in frozen or paraffin wax sections and therefore that frozen sections can be used to microstage melanoma. Interobserver variations seem to be a more likely source of erroneous measurements of tumour thickness.

Can psychotherapy help patients with psoriasis?

Two groups of people with psoriasis attended a short series of meetings conducted by a clinical psychologist. During these sessions the patients were given the opportunity to discuss between themselves problems created by their skin complaint and they were taught specific relaxation techniques for use whenever they felt under stress. Psychological tests showed that the participants were a noticeably anxious group compared to the general population. However, their levels of anxiety were significantly reduced by the end of the study. There was also a modest trend towards physical improvement. No such changes were seen in a matched control group.

A comparison of antibodies to type VII and type IV collagen laminin and amnion as epidermal basement membrane markers

We have compared four monoclonal antibodies which label basement membrane components using an indirect immunoperoxidase method in frozen sections of skin biopsies. The antibodies LH 7.2 and GB3 showed expression limited to epidermal and adnexal basement membrane. Antibodies to laminin and type IV collagen also decorated dermal blood vessels and stromal components. The antibodies LH 7.2 and GB3 are more suitable for labelling epidermal basement membrane in the study of cutaneous lesions.

Type VII collagen antibody LH 7.2 identifies basement membrane characteristics of thin malignant melanomas

A monoclonal antibody (LH 7.2) to the carboxy terminal of type VII collagen has been used in an indirect immunoperoxidase method on frozen sections of biopsies of benign compound and intradermal cellular naevi, dysplastic naevi, and malignant melanomas, to label the epidermal basement membrane. Benign intradermal naevi had an intact membrane with the dermal naevus cell component lying beneath it. Compound naevi showed proliferating junctional nests of naevus cells pushing through the membrane towards the dermis beneath. In contrast, dysplastic naevi and melanomas showed a progressive displacement of the membrane downwards. Thin lesions were confined above the membrane. With increasing tumour thickness, discontinuities in the membrane were seen and foci of invasive growth through the line of the membrane were identified. These studies suggest that the good prognosis of thin melanomas is associated with confinement of the tumour within an expanded epidermis above the basement membrane.

Autopsy findings in a patient who had an adrenal-to-brain transplant for Parkinson's disease

Autopsy findings in a patient who had an adrenal-to-brain transplant for Parkinson's disease 4 months before his death showed adrenal tissue in the basal ganglia, but it was necrotic. Symptomatic improvement lasted for only 2 weeks.

Distinctive epidermal atypia in immunosuppression-associated cutaneous malignancy

The histopathological appearance of proliferative squamous lesions removed from the skin of iatrogenically immunosuppressed patients differs subtly from that of classical malignant and premalignant epidermal lesions. The majority of cases show 'Bowenoid' changes with a marked degree of cellular atypia including characteristic multinucleate cells.

Comparison of a total intravenous anaesthetic technique using a propofol infusion, with an inhalational technique using enflurane for day case surgery

A total intravenous anaesthetic technique with a propofol infusion for maintenance of anaesthesia was compared with an inhalational technique that used oxygen, nitrous oxide and enflurane in 98 unpremedicated patients who presented for day case surgery. Overall quality of anaesthesia during induction and maintenance was comparable in both groups. Quality of maintenance of anaesthesia in the propofol group was improved by an increase of the initial infusion rate from 12 to 15 mg/kg/hour. There was a larger decrease in arterial blood pressure after induction in the propofol group but no difference in blood pressure between the groups during maintenance. Recovery times and scores using the Steward scoring system were not significantly different. Nausea and vomiting were slightly less frequent in the propofol group.

Lamellar bodies in hyperkeratosis lenticularis perstans

An ultrastructural study of lesional skin from 4 subjects with hyperkeratosis lenticularis perstans (Flegel's disease) demonstrated variable numbers of lamellar bodies of normal size and architecture within cells of the stratum granulosum and the upper stratum spinosum. Their characteristic lamellate inclusions were frequently observed within the intercellular spaces. These observations suggest that the lamellar bodies are qualitatively normal in Flegel's disease.

A clinicopathological study of Flegel's disease (hyperkeratosis lenticularis perstans)

The clinical and histopathological features of 12 female patients with Flegel's disease were studied. The onset of this dermatosis was delayed until adulthood. The eruption consisted of scaly papules 1-5 mm in diameter which developed principally on the lower legs, upper arms and pinnae. Histopathologically there were discrete foci of hyperkeratosis with some parakeratosis over an attenuated and partially spongiotic epidermis. A genetic influence in this disorder was suggested by its occurrence in sisters in two families and in a mother and daughter. Immunohistochemical and biochemical studies suggested that there is a disorder of keratinocyte proliferation in the disease.

Lichen aureus: a localized persistent form of pigmented purpuric dermatitis

Localized persistent pigmented macules and plaques due to a chronic form of pigmented purpuric dermatitis are described in forty-two patients. The designation 'lichen aureus' for this eruption can be justified because of the striking yellowish or bronze-like colour assumed by many of the lesions. The lower legs were the commonest sites but other body regions can be affected also. Histologically lichen aureus differs from other pigmented purpuric dermatoses in the density of the lichenoid tissue reaction and the marked accumulation of pigment-containing macrophages. Recently developed endothelial cell markers have been studied in selected cases.

The role of diet in the management of atopic eczema

The underlying cause of atopic eczema remains unknown but both food intolerance and dietary deficiency--notably of essential fatty acids--may well be exacerbating factors. Studies investigating the involvement of food intolerance have shown that only some children obtain benefit from avoiding milk and eggs. In other cases, the use of an elimination or of a chemically-defined diet followed by challenge with specific foods may allow an effective personalized diet to be devised. Skin-prick tests and measurement of IgE levels have proved to be unreliable predictors of reactions to food. The development of a reliable test to assess food intolerance would represent a significant advance in the treatment of atopic eczema.

Lymphomatoid vasculitis

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The diagnostic value of parakeratosis

A study of dermatopathological specimens exhibiting parakeratosis has been made and the parakeratosis classified on morphological and topographical criteria. Twelve patterns of parakeratosis have been identified and their association with particular pathological conditions described.