Anticonvulsant activity of aqueous extract of Leonotis leonurus

Water extract of Leonotis leonurus was tested for anticonvulsant activity against seizures produced in mice by pentylenetetrazole, picrotoxin, bicuculline and N-methyl-DL-aspartic acid (intraperitoneal injections). L. leonurus extract in the doses of 200 and 400 mg/kg respectively protected 37.5% and 50% of animals used and significantly (p < 0.05; Student's t-test) delayed pentylenetetrazole (90 mg/kg)-induced tonic seizures. Similarly, the same doses of L. leonurus extract significantly (p < 0.05; Student's t-test) delayed the onset of tonic seizures produced by picrotoxin (8 mg/kg) and N-methyl-DL-aspartic acid (400 mg/kg). However, all the doses of aqueous extract of L leonurus used did not alter the seizures induced by bicuculline (20 mg/kg) to any significant extent. The data suggest that the extract of L. leonurus has anticonvulsant activity and may probably be acting through non-specific mechanisms, since it affects both gabaergic and glutaminergic systems. High performance liquid chromatography (HPLC) and phytochemical tests carried out respectively show a spectrum profile, characteristic of L. leonurus and the presence of alkaloids, saponins and tannins in the extract.

Evidence for functional partitioning of the rabbit digastric muscle

The rabbit digastric muscle has a single belly that opens and retracts the mandible. It does not contain connective tissue partitions, and all fibers arise from the same tendon and insert into a single broad site. Historically, it was assumed that the muscle functioned as a single unit. Since we had preliminary evidence that this might not be the case, we carried out five small studies in rabbits. First, we showed that electromyographic (EMG) activity varies between recording sites within the muscle during the masticatory cycle induced by repetitive stimulation of the sensorimotor cortex. We found that EMG activity in the caudal region sometimes began before the anterior EMG during mastication when the jaw swung to the side of the muscle, but the two regions became active at the same time during other patterns. We next showed that separate branches of the mylohyoid nerve enter the anterior, intermediate and caudal regions of the digastric. However, a separate study showed that the motor endplates were distributed across a continuous sheet, consistent with a single anatomical partition. We then stimulated single nerve branches to deplete glycogen. By comparing the optical density of fibers labeled by the periodic acid-Schiff method for glycogen, we were able to show that the three branches innervate separate regions of the muscle. Finally, we applied either FluoroGold or Fast Blue dyes to the central cut ends of the branches to label the cell bodies of the three pools of motoneurons. These were found within the middle and caudal thirds of the trigeminal motor nucleus, but there appeared to be no spatial separation of the three pools or double labeling of cells. We conclude that the digastric muscle contains two and possibly three functional subregions. The fact that the motoneurons are intermingled suggests that the distribution of motor commands to the three pools is not based on their location.

Rapid mutation detection by the transgenomic wave analyser DHPLC identifies MYOC mutations in patients with ocular hypertension and/or open angle glaucoma

AIMS

To rapidly screen Scottish patients with a family history of open angle glaucoma (OAG) or ocular hypertension (OHT) for mutations in the myocilin gene (MYOC) and develop a new rapid screening method for MYOC mutation detection.

METHODS

All three exons of the MYOC gene were amplified by PCR from genomic DNA and subjected to direct DNA sequencing. Mutation detection methodology was also developed based on denaturing high performance liquid chromatography (DHPLC). A recurrent mutation was investigated by analysis of microsatellite haplotypes at the MYOC gene locus.

RESULTS

Mutations were identified by DNA sequencing in four families. MYOC mutation Q368X was found in three kindreds and the fourth family carried the mutation G367R. The Q368X mutation was found to be associated with the same haplotype for markers closely flanking the MYOC gene. The mutations were identified by direct sequencing and were also readily detected by DHPLC analysis of PCR fragments, demonstrating that this is a robust method for MYOC analysis in future.

CONCLUSIONS

Mutations in the MYOC gene were identified in patients presenting with highly variable phenotypes from normal through OHT to severe OAG. Haplotype analysis showed that mutation Q368X is likely to be an ancestral mutation in this population. DHPLC analysis is an accurate, rapid and cost effective method for MYOC mutation analysis in large population samples.

Programmed-life plastics from polyolefins: a new look at sustainability

The term "sustainable" is often assumed to be synonymous with "renewable". However, polymers made from renewable natural resources are not necessarily eco-efficient. Cellulose-based polymers utilize more nonrenewable fossil fuels and are more polluting during manufacture than petro-based polymers. Sustainable polymers also have to be industrially acceptable, and although ultimate biodegradability in the natural environment is important, polymer-based products are required to biodegrade in a controlled way. Service life may be a year or more before the commencement of environmental degradation occurs. Many natural polymers such as rubber, lignin, and humus, like the synthetic polyolefins, biodegrade by an oxidative mechanism (oxo-biodegradation), and consequently much of nature's biological waste cannot satisfy the rapid mineralization criteria currently advocated by standards committees for synthetic polymers. Although biometric tests are more convenient to use than full composting tests, they are meaningless when applied to hydrocarbon polymers, whether natural or synthetic, since oxo-biodegradation is a slower process than hydro-biodegradation at ambient temperatures. Biodegradation standards currently proposed are unrealistic and will need to be modified on the basis of recent scientific evidence.

Protease-activated receptor 2, a receptor involved in melanosome transfer, is upregulated in human skin by ultraviolet irradiation

Previous studies have shown that the protease-activated receptor 2 is involved in skin pigmentation through increased phagocytosis of melanosomes by keratinocytes. Ultraviolet irradiation is a potent stimulus for melanosome transfer. We show that protease-activated receptor 2 expression in human skin is upregulated by ultraviolet irradiation. Subjects with skin type I, II, or III were exposed to two or three minimal erythema doses of irradiation from a solar simulator. Biopsies were taken from nonexposed and irradiated skin 24 and 96 h after irradiation and protease-activated receptor 2 expression was detected using immunohistochemical staining. In nonirradiated skin, protease-activated receptor 2 expression was confined to keratinocytes in the lower one-third of the epidermis. After ultraviolet irradiation protease-activated receptor 2 expression was observed in keratinocytes in the upper two-thirds of the epidermis or the entire epidermis at both time points studied. Subjects with skin type I showed delayed upregulation of protease-activated receptor 2 expression, however, compared with subjects with skin types II and III. Irradiated cultured human keratinocytes showed upregulation in protease-activated receptor 2 expression as determined by immunofluorescence microscopy and Western blotting. Cell culture supernatants from irradiated keratinocytes also exhibited a dose-dependent increase in protease-activated receptor-2 cleavage activity. These results suggest an important role for protease-activated receptor-2 in pigmentation in vivo. Differences in protease-activated receptor 2 regulation in type I skin compared with skin types II and III suggest a potential mechanism for differences in tanning in subjects with different skin types.

Functional analyses of two alternative isoforms of the transcription factor Pax-5

The Pax-5 gene plays a central role in B cell development, activation, and differentiation. At least four different isoforms have been identified, of which isoform Pax-5a has been extensively studied, while functions for alternative isoforms were previously unknown. Here, using a transient transfection system, we provide evidence that alternative isoform Pax-5d acts as a dominant-negative regulator by suppressing activity of Pax-5a in a dose-dependent manner. In contrast, co-expression in the presence of alternative isoform Pax-5e causes an increase in Pax-5a activity. Protein studies on Pax-5e using Western blot analysis revealed that this 19-kDa isoform migrates as a 27-kDa species on SDS-polyacrylamide electrophoresis gels, while a mutant Pax-5e form in which a C-terminal cysteine residue has been mutated, runs at the expected 19 kDa. Using both Western blot and immunoprecipitation assays, we further provide evidence that this size discrepancy may be caused by a tight association between Pax-5e and a thioredoxin-like factor. Comparison of various B cell lines as well as resting and lipopolysaccharide-activated mature B lymphocytes shows that increased B cell proliferation correlates with increased levels of Pax-5e/thioredoxin, whereas increased Pax-5d amounts correlate with inhibition of cell growth. Together, our results suggest that during activation and differentiation of B lymphocytes, Pax-5a function is modulated by two alternative spliced isoforms: the dominant negative Pax-5d isoform may mediate inhibition of Pax-5a activity in resting B cells, while alternative isoform Pax-5e associated with thioredoxin may increase Pax-5a activity through an unknown (redox) mechanism.

Discharge patterns of neurons in the medial pontobulbar reticular formation during fictive mastication in the rabbit

In this study, we describe functional characteristics of neurons forming networks generating oral ingestive motor behaviours. Neurons in medial reticular nuclei on the right side of the brainstem between the trigeminal and hypoglossal motor nuclei were recorded in anaesthetized and paralysed rabbits during two types of masticatory-like motor patterns induced by electrical stimulation of the left (contralateral) or right (ipsilateral) cortical masticatory areas. Sixty-seven neurons in nucleus reticularis pontis caudalis (nPontc), nucleus reticularis parvocellularis (nParv), and nucleus reticularis gigantocellularis (Rgc) were studied. These were classified as phasic or tonic depending on their firing pattern during the fictive jaw movement cycle. Phasic neurons located in the dorsal part of nPontc were active during the jaw opening phase, whilst those in dorsal nParv tended to fire during the closing phase. In most neurons, burst duration and firing frequency changed between the two motor patterns, but there was little change in phase of firing. Tonic units were mainly recorded in the ventral half of nPontc, and at the junction between Rgc and caudal nParv. Cortical inputs with short latency from the contralateral masticatory area were more frequent in phasic (82%) than tonic (44%) neurons, whilst inputs from the ipsilateral cortex were equal in the two subgroups (57% and 56%). Phasic neurons had significantly shorter mean contralateral than ipsilateral cortical latencies, whilst there was no difference among tonic neurons. Intra- and perioral primary afferent inputs activated both types of neurons at oligo-synaptic latencies. Our results show that subpopulations of neurons in medial reticular nuclei extending from the caudal part of the trigeminal motor nucleus to the rostral third of the hypoglossal motor nucleus are active during the fictive masticatory motor behaviour. Unlike masticatory neurons in the lateral tegmentum, the medial subpopulations are spatially organized according to discharge pattern.

Pseudotumour in von Willebrand disease

Pseudotumour is a rare complication of haemophilia; it has previously been reported in patients with moderate or severe haemophilia and rarely in mild disease. We report a case of a proximal pseudotumour occurring in a 36-year-old patient with mild von Willebrand disease (vWD) who made a good recovery with conservative management. Surgery has been advocated as the optimal treatment for proximal pseudotumours due to the risk of continued bleeding and progression. However, in mild haemophilia or vWD, where the risk of spontaneous bleeds is low, conservative management may be an appropriate alternative.

"War stories": AIDS prevention and the street narratives of drug users

The day-to-day discourse of illicit drug users is replete with stylized narratives of street experience. These "war stories," as they are popularly known, are shared among drug users as they hustle for money, purchase drugs, get high, and hang out in diverse street locations. Drug-user narratives, which describe complex adventures and grave suffering, are primary ethnographic sources of information about patterns of drug consumption and risk behaviors. Importantly, in the time of AIDS, street narratives provide a much-needed window on the generally hidden lives of socially marginalized street drug users. As part of an effort to put the analysis of drug-user war stories to use in HIV prevention, in this article the authors analyze a corpus of street narratives told to members of an HIV-prevention research team in Hartford, Connecticut.

Follicular mycosis fungoides: a case report and review of the literature

BACKGROUND

Follicular mycosis fungoides is an unusual variant of mycosis fungoides (MF). Unlike classic MF where atypical lymphocytes show a predilection for the epidermis (epidermotropism), follicular MF displays a malignant lymphocytic infiltrate tropic for hair follicles (folliculotropism). This malignant lymphocytic infiltrate results in follicular disruption typically manifesting clinically as plaques, comedones and follicular papules.

METHODS

This report describes a 40-year-old patient with follicular MF presenting as nodules on the face and chest. Histologic examination of the patient's biopsy revealed a folliculocentric infiltrate of atypical lymphocytes with sparing of the epidermis.

RESULTS AND CONCLUSIONS

Our case is discussed in the context of previously reported cases of follicular MF; we also include a review of all cases of follicular MF published to date that meet the strict criterion for this diagnosis.

Septo-optic dysplasia and unexpected adult death--an autopsy approach

A 20-year-old woman who suffered from septo-optic dysplasia died unexpectedly following a presumed viral gastroenteritis. Autopsy and neuropathological examination confirmed optic nerve hypoplasia with absence of the septum pellucidum. Marked adrenal gland hypoplasia reflected hypothalamic hypopituitarism. The small and large intestines were dilated and filled with liquid fecal material. This case demonstrates that individuals with septo-optic dysplasia may be at risk of unexpected death at all ages. The complexity of mechanisms of death in rare dysmorphic conditions may be overlooked if relevant clinical information is not available at the time of autopsy and unless specific steps are taken to clearly delineate the underlying features of the condition.

Direct-Sun column ozone retrieval by the ultraviolet multifilter rotating shadow-band radiometer and comparison with those from Brewer and Dobson spectrophotometers

A methodology for direct-Sun ozone retrieval using the ultraviolet multifilter rotating shadow-band radiometer (UV-MFRSR) is presented. Total vertical column ozone was retrieved in three stations: Mauna Loa, Hawaii, in the U.S., and Regina, Saskatchewan, and Toronto, Ontario, in Canada, from direct solar irradiances of the UV-MFRSR at 325-, 305-, 332-, and 311-nm channels (2-nm FWHM). The total uncertainty of ozone retrievals in this study is +/-2.0%. For Mauna Loa the mean ratios of the UV-MFRSR column ozone retrievals to the collocated Dobson and Brewer were 0.998 and 0.986 between May and September of 1999. The mean ratio of UV-MFRSR retrievals to the collocated Brewer retrievals was 1.012 in Toronto between April and August of 1999, and the mean ratio of retrievals of the UV-MFRSR to the collocated Brewer was 0.988 in Regina between June and September of 1999. Total vertical column ozone values for solar zenith angles of >70 degrees were not considered, because of the signal-to-noise ratio and the angular response of the instruments, and were not used in the evaluation. The advantages of total vertical column ozone retrieval using UV-MFRSR include relatively low cost, computer-controlled operation, automated calibration stability checks, and minimal maintenance. It allows for the real-time measurement of total vertical column ozone. The UV-MFRSR is being used at 28 sites across the United States and 2 sites in Canada that form the U.S. Department of Agriculture UV-B Radiation Monitoring and Research Program. This constitutes a unique network of total vertical colunm ozone measurement.

A study of family carers of people with a life-threatening illness. 2: Implications of the needs assessment

This is the second of two articles that consider the findings of a Carers' Assessment of Difficulties Index (CADI) (Nolan et al, 1998) delivered in a palliative care context. It analyses the implications of these findings for practitioners concerned with the delivery of palliative care to such carers and their families. The development of support strategies and services addressing their needs are also presented against a backdrop of transactional stress theory. For people new to caring, recommendations for the local service include early intervention through informational support and validation of their emotional responses to caring; for longer-term carers they include assistance with cognitive reappraisal of the stressfulness of caring and regular 'respite' and socializing opportunities. These are taking place in a political climate that finally recognizes the contribution and value of carers (Department of Health, 1999). The research behind these carer identity and recognition initiatives aims to apply the spirit of public recognition and practical wisdom of palliative care expertise by responding sensitively to the specific needs of carers of people with a life-threatening illness.

A study of family carers of people with a life-threatening illness 1: the carers' needs analysis

This study examines the educational and supportive requirements of carers of people with a life-threatening illness. Responses would indicate the content and format of an educational or supportive programme of material that might then be developed. Twenty-four carers known to a Macmillan team in a national health service trust in the north of England were targeted for participation and quantitative data collected were analysed manually. Qualitative data arising from the carer interviews were subjected to a simple content analysis exercise that led to the identification of some overarching themes. In both strands of the research, similar emergent themes of physical, emotional and social stress were identified. Findings suggest that consideration of carers' age, length of caring experience and gender may be helpful in understanding their experience of stress and in developing support strategies.

Analgesic and antipyretic effects of Dodonaea angustifolia and Salvia africana-lutea

Water extracts of Dodonaea angustifolia L. and Salvia africana-lutea L., were investigated for analgesic and antipyretic activities using acetic acid writhing and hot plate tests, and lipopolysaccharide (LP)-induced pyrexia test in mice and rats, respectively. D. angustifolia and S. africana-lutea significantly inhibited acetic acid-induced writhing and also significantly delayed the time of reaction of mice to thermal stimulation produced by the hot plate. D. angustifolia and S. africana-lutea significantly reduced fever induced by LP. Paracetamol produced similar effects to D. angustifolia and S. africana-lutea on the acetic acid-induced writhing but has no effect on hot plate-induced nociception and on pyrexia produced by LP. These data indicate the analgesic and antipyretic potential of D. angustifolia and S. africana-lutea.

Ganglioglioma of the lateral ventricle presenting with blepharospasm - case report and review of the literature

Gangliogliomas of the lateral ventricle are unusual tumours of the central nervous system. We report a 25-year-old female who presented with a 4-week history of generalized headaches associated with left-sided blepharospasm. Clinical examination revealed bilateral papilloedema but no focal neurological deficits. Computed tomography and magnetic resonance imaging demonstrated a large lesion within the left lateral ventricle. Gross total surgical resection of the lesion was performed through a para-sagittal, trans-callosal approach. Histopathological analysis revealed the diagnosis of ganglioglioma. The post-operative course was uneventful, with complete resolution of both the headaches and blepharospasm. The presentation with an ipsilateral blepharospasm has never previously been reported in the setting of a lateral ventricular tumour.