Unconscious learning during surgery with propofol anaesthesia † †This article is accompanied by Editorial II

BACKGROUND

Learning during anaesthesia has been demonstrated, but little is known about the circumstances under which it may occur. This study investigated the hypothesis that learning during anaesthesia occurs during, but not before, surgical stimulation.

METHODS

Words were played through headphones to 64 day-surgery patients during propofol anaesthesia. Fourteen words were played repeatedly (15 times) for 1 min each either before (n=32) or during (n=32) surgical stimulation. The depth of anaesthesia was estimated using the bispectral index (BIS). Heart rate, ventilatory frequency, mean arterial pressure, end-tidal carbon dioxide concentration, and infusion rate of propofol were recorded at 1 min intervals during word presentation. On recovery, memory was assessed using an auditory word stem completion test and word recognition test.

RESULTS

The mean BIS, arterial pressure, end-tidal carbon dioxide and heart rate during word presentation did not differ between the groups. The infusion rate of propofol and the ventilatory frequency were significantly greater in the during-surgical stimulation group. There was no evidence for explicit recall or recognition, nor of awareness during anaesthesia (median mean-BIS=38 in the before-surgical stimulation group and 42 in the during-surgical stimulation group). Only patients who were played words during surgical stimulation showed significant implicit memory on recovery (mean score=0.08, P<0.02) However, their scores were not significantly higher than those of the before-surgical stimulation group (mean score=0.01).

CONCLUSIONS

Learning during anaesthesia seems more likely to occur during rather than before surgical stimulation at comparable anaesthetic depth. We hypothesize that surgical stimulation facilitates learning during anaesthesia, independently of its effects on anaesthetic depth.

Prevalence of anemia in adult rural population of north India

OBJECTIVES

To find the prevalence of anemia in adult males and non-pregnant females of rural north Indian population.

METHODS

During an epidemiological survey on hypertension in rural population of north India (n=2559), a random sample of 215 individuals underwent blood investigations including hemoglobin estimation.

RESULTS

The overall prevalence of anemia in 16-70 years of age group was 47.9% (n=215), being 50% (n= 136) among females and 44.3% (n=78) among males. Low socioeconomic status, illiteracy and lower body mass index, were associated with higher prevalence of anemia.

CONCLUSIONS

The finding of higher prevalence of anemia in adult males need further investigation and corroboration in other studies. The intervention for anemia should be directed on the community as a whole.

Agreement among Ayurvedic practitioners in the identification and treatment of three cases of inflammatory arthritis

OBJECTIVE

To conduct a preliminary investigation into the consistency of approach between three Ayurvedic medicine experts on treatments for inflammatory polyarthritis.

METHODS

A convenience sample of three experienced Ayurvedic practitioners was recruited. These practitioners independently assessed three subjects with inflammatory polyarthritis for health status, treatment history, and lifestyle, conducted a physical examination, and then independently determined the treatment plan. The treatment plan was recorded on standardized collection forms. The subject examination order was randomized for each practitioner. Following completion of the assessments, a facilitated discussion among the practitioners permitted each to discuss all aspects of the recommended therapies. Proceedings were audio-taped and the content analyzed.

RESULTS

All three practitioners agreed upon a unified concept of Ayurvedic disease origin, disease diagnosis, and treatment approach for each patient. Seven specific treatment groupings (i.e. modalities) emerged: diet, exercise, relaxation, analgesic, anti-inflammatory, immune-enhancing, and detoxification/cleansing. Based on the single visit, the practitioners agreed upon 17 of 21 treatment groups for the three patients.

CONCLUSION

Despite Ayurvedic medicine's individualized approach, considerable agreement existed among the practitioners studied. The identified Ayurvedic treatment approaches require investigation in a controlled clinical setting.

Isolated lipid abnormalities in rural and urban normotensive and hypertensive north-west Indians

BACKGROUND

Lipid abnormalities are common in patients with hypertension. The prevalence of isolated lipid abnormalities is not known in normotensive and hypertensive population of north-west India.

METHODS

We studied the prevalence of isolated low high density lipoprotein cholesterol (IL-HDLC), isolated high low density lipoprotein cholesterol (IH-LDLC) and isolated high triglycerides (IH-TG) abnormalities among rural and urban normotensive and hypertensives of north-west India.

RESULTS

The prevalence of lipid abnormalities was 47.6% and 51.4% in rural normotensives and hypertensives and 43.8% and 46.8% in urban normotensives and hypertensives respectively. The prevalence of IL-HDLC varied from 3.8% to 23.7% among hypertensives and 19.4% to 30.4% among normotensives. The prevalence of IH-TG abnormalities was 11.8% to 18.8% among hypertensives and 7.0% to 15.4% among hypertensives. The prevalence of isolated high LDLC abnormalities was low (0.8-9.2%). There was no significant difference in these abnormalities in relation to age and sex except IH-LDLC in male hypertensives.

CONCLUSION

Isolated low HDLC and isolated high TG were the commonest isolated lipid abnormalities among rural and urban population of north-west India whereas isolated high LDLC was uncommon.

Cytomegalovirus co-infection in patients with HIV/AIDS in north India

BACKGROUND & OBJECTIVES

Cytomegalovirus (CMV) is a frequent opportunistic infection in immunocompromised individuals particularly those receiving organ transplants and harbouring HIV infection. The classical CMV syndrome may be seen in only a small percentage of patients and tissue diagnosis is cumbersome, costly and requires hospitalization. Hence there is an urgent need to establish accurate and early diagnosis for proper institution of therapy. An attempt was made to detect active CMV co-infection in patients with HIV/AIDS using three assays and the positivity rates in the 2 groups compared.

METHODS

In the present study, we used a highly sensitive polymerase chain reaction (PCR) for immediate early gene of CMV, pp65 antigenaemia assay and IgM ELISA assay to detect the presence of CMV co-infection in 37 patients with AIDS and 32 healthy HIV seropositives. Thirty healthy laboratory workers served as normal controls.

RESULTS

Of the 37 patients with AIDS, 12 (32.4%) showed a positive reaction by PCR and only 4 patients were positive by the antigenaemia assay. Of the 32 HIV seropositives, only one was positive by PCR (3%), and all were negative for antigen assay. None of the controls showed positivity by any of the tests. The difference in PCR positivity rates between HIV seropositives and patients with AIDS was significant (P < 01). IgM antibodies were positive in four (10.3%) AIDS patients and only one (3%) HIV seropositive, the difference was insignificant. The difference in antigen positivity between IIIV seropositives and AIDS patients was also insignificant.

INTERPRETATION & CONCLUSION

CMV appears to be an important co-infection in patients with AIDS in India and PCR is a powerful tool for detection of CMV in blood and is superior to the antigenaemia assay. PCR can be performed with a small volume of blood avoiding any invasive procedure, and can provide quick information for timely institution of therapy.

BDNF overexpression increases dendrite complexity in hippocampal dentate gyrus

There is increasing evidence that brain-derived neurotrophic factor (BDNF) modulates synaptic and morphological plasticity in the developing and mature nervous system. Plasticity may be modulated partially by BDNF's effects on dendritic structure. Utilizing transgenic mice where BDNF overexpression was controlled by the beta-actin promoter, we evaluated the effects of long-term overexpression of BDNF on the dendritic structure of granule cells in the hippocampal dentate gyrus. BDNF transgenic mice provided the opportunity to investigate the effects of modestly increased BDNF levels on dendrite structure in the complex in vivo environment. While the elevated BDNF levels were insufficient to change levels of TrkB receptor isoforms or downstream TrkB signaling, they did increase dendrite complexity of dentate granule cells. These cells showed an increased number of first order dendrites, of total dendritic length and of total number of branch points. These results suggest that dendrite structure of granule cells is tightly regulated and is sensitive to modest increases in levels of BDNF. This is the first study to evaluate the effects of BDNF overexpression on dendrite morphology in the intact hippocampus and extends previous in vitro observations that BDNF influences synaptic plasticity by increasing complexity of dendritic arbors.

Tattoo ink darkening of a yellow tattoo after Q-switched laser treatment

The popularity of tattoos is burgeoning with 20-30 million tattooed individuals in the Western World. Requests for removal can be expected to rise concurrently with increased applications. Laser removal of tattoos is potentially a more cosmetically acceptable method of removing tattoos than surgical excision or dermabrasion. Nevertheless, complications and side-effects can result from laser treatment and include scarring, hypopigmentation, hyperpigmentation, partial removal, infection, bleeding and tattoo ink darkening. The latter has been reported for flesh-toned and red tattoos. Such a complication has never been reported for the laser treatment of a yellow tattoo in the dermatological literature. We describe a case of tattoo ink darkening of a yellow tattoo after treatment with the 532 nm quality-switched Neodymium : Ytrrium-Aluminium Garnet laser to highlight clinicopathological features. The mechanism by which some tattoos darken after laser treatment is not clearly understood. We review darkening of tattoos after laser treatment to raise awareness of this important complication. This paper will help to facilitate discussions with the patient and in obtaining informed consent prior to commencing treatment. Tattoo ink darkening of a yellow tattoo adds to the growing list of complications resulting from attempts at tattoo removal.

Epidural abscess and Staphylococcus aureus endocarditis - a rare association

Epidural abscess is a relatively uncommon disorder. Although the surgical management is the mainstay of treatment, there are case reports of it being managed conservatively in selected patients. We report a patient who presented with quadreparesis due to epidural abscess and had infective endocarditis due to Staphylococcus aureus septicemia. Both epidural abscess and infective endocarditis were managed conservatively with intravenous antibiotics given for four weeks, with complete recovery of patient.

Structure, chromosomal location, and analysis of the canine Cu/Zn superoxide dismutase (SOD1) gene

Mutations in Cu/Zn superoxide dismutase (SOD1), a major cytosolic antioxidant enzyme in eukaryotic cells, have been reported in approximately 20% of familial amyotrophic lateral sclerosis (FALS) patients. Hereditary canine spinal muscular atrophy (HCSMA), a fatal inherited motor neuron disease in Brittany spaniels, shares many clinical and pathological features with human motor neuron disease, including FALS. The SOD1 coding region has been sequenced and cloned from several animal species, but not from the dog. We have mapped the chromosomal location, sequenced, and characterized the canine SOD1 gene. Extending this analysis, we have evaluated SOD1 as a candidate for HCSMA. The 462 bp SOD1 coding region in the dog encodes 153 amino acid residues and exhibits more than 83% and 79% sequence identity to other mammalian homologues at both the nucleotide and amino acid levels, respectively. The canine SOD1 gene maps to CFA31 close to syntenic group 13 on the radiation hybrid (RH) map in the vicinity of sodium myo/inositol transporter (SMIT) gene. The human orthologous SOD1 and SMIT genes have been localized on HSA 21q22.1 and HSA 21q21, respectively, confirming the conservation of synteny between dog syntenic group 13 and HSA 21. Direct sequencing of SOD1 cDNA from six dogs with HCSMA revealed no mutations. Northern analysis indicated no differences in steady-state levels of SOD1 mRNA.

Audit of a melanoma screening day in the U.K.: clinical results, participant satisfaction and perceived value

BACKGROUND

The incidence of cutaneous malignant melanoma (MM) has risen significantly over the last 50 years in caucasian populations. Mortality is related to the Breslow thickness of the lesion, and early detection followed by complete surgical excision is crucial to reducing this. Skin screening events have been advocated as a means of detecting greater numbers of MMs in the earlier and thinner stages.

OBJECTIVES

To assess the feasibility and effectiveness of this approach in the U.K.

METHODS

The Department of Dermatology, Singleton Hospital, Swansea, U.K. offered a 1-day melanoma screening event in summer 1998 at which 832 consecutive individuals were seen. A postal questionnaire 1 year after the event audited participant perceived value and satisfaction.

RESULTS

Three MMs were identified (yield 1 : 277), all < 0.75 mm in thickness. Despite high participant satisfaction and perceived value, the pick-up rate of malignancy was significantly lower than at rapid access pigmented lesion clinics.

CONCLUSIONS

In a country such as the U.K., with comprehensive health coverage and a low incidence of MM, triage for melanoma and referral to specialists by general practitioners may be more cost and time effective.

VEGF increases permeability of the endothelial cell monolayer by activation of PKB/akt, endothelial nitric-oxide synthase, and MAP kinase pathways

VEGF is a key regulator of vascular permeability. However, its signaling pathways are incompletely understood. We tested the hypothesis that VEGF regulates endothelial cell (EC) permeability by activating PKB/akt, NOS, and MAP kinase dependent pathways using human umbilical vein EC (HUVEC). Permeability was measured from FITC-dextran 70-kDa flux across the EC monolayer at baseline and after VEGF at 0.034, 0.068, 1, 10, and 100 nM. VEGF increased HUVEC permeability to FITC-dextran in a dose-dependent manner. VEGF (1 nM) increased permeability from 3.9 x 10(-6) +/- 0.7 x 10(-6) to 14.0 x 10(-6) +/- 1.7 x 10(-6) cm/s (mean +/- SEM; P < 0.001). Permeability changes were also assessed after treatment with 1, 10, and 100 nM wortmannin (PI 3-kinase inhibitor); 0.01, 0.1, and 1.0 nM LY294002 (PI 3-kinase inhibitor); 200 microM l-NMMA (NOS inhibitor); 2.7 microM AG126 (p42/44(MAPK) inhibitor); and 0.006, 0.06, and 0.6 microM SB203580 (p38(MAPK) inhibitor). All inhibitors blocked VEGF-induced permeability changes. Our data demonstrate that (1) VEGF increases permeability of EC monolayers in a dose-dependent fashion, and (2) VEGF-induced permeability is mediated through PI-3 kinase-PKB, NOS, and MAP-kinase signaling cascades. These observations suggest that microvascular hyperpermeability associated with inflammation and vascular disease is mediated by activation of these EC signaling pathways.

The first case of exophytic pilomatricoma in an Asian male

Pilomatricomas are benign cutaneous neoplasms that occur frequently in children and usually present as slow-growing, firm, dermal nodules. They are the second most common skin lesion excised from children. A rare exophytic variety has been described, but to our knowledge this has not previously been reported in Asian children. We present this case to highlight the clinical features and to affirm that race may not play a role in the etiology of pilomatricomas. We also illustrate how these lesions can be effectively treated by shave excision.