Reliability of telemedicine in evaluating skin tumors

OBJECTIVES

To determine the reliability of videoconferencing technology in evaluating skin tumors, the impact of the technology on the clinicians' degree of suspicion that a skin tumor is malignant, and the recommendation to do a biopsy.

MATERIALS AND METHODS

Four skin cancer screenings were conducted at rural health care facilities in eastern North Carolina that were connected to East Carolina University School of Medicine. A dermatologist saw the patients in person at the local facility, and the same patient was seen by a dermatologist via a T-1 connection to Greenville, North Carolina.

RESULTS

The two physicians were in absolute agreement on 59% of the 107 skin tumors evaluated. There were five lesions identified by the on-site dermatologist as a probable or definite malignancy. The degree of concern about a lesion being malignant and the decision whether to do a biopsy were not significantly different, as shown by kappa analysis.

CONCLUSION

The concern about the malignancy of a particular skin lesion and the recommendation whether to do a biopsy were not significantly affected by telemedicine technology.

Are omphalocele and neural tube defects related congenital anomalies?: Data from 21 registries in Europe (EUROCAT)

We have analyzed the association between omphalocele and neural tube defects (O/NTD) previously reported in epidemiological studies of EUROCAT registry data [Dolk et al., 1991; Calzolari et al., 1995]. By examining differences in prevalence between the United Kingdom and Ireland (UKI) and Continental Europe and Malta (CEM) and differences in sex ratio, the possible etiopathogenetic differences between O/NTD association and omphalocele without NTD and NTD without omphalocele were investigated. The distribution of O/NTD cases according to NTD site in the two geographic areas shows in the UKI a tendency for omphalocele to associate with anencephaly/spina bifida and with anencephaly. In CEM centers, these types of NTD are much rarer. The pattern of other anomalies occurring in combination with O/NTD association in the same babies was also analysed.

Reliability of dermatology teleconsultations with the use of teleconferencing technology

BACKGROUND

Recent advances in telecommunications technology allow physicians to consult on patients at a distance via an interactive video format. Few data exist as to the reliability of this form of consultation.

OBJECTIVE

Our purpose was to measure the degree of concordance between a dermatologist seeing a patient in a clinic and another dermatologist seeing the same patient over a commercially available videoconferencing system.

METHODS

Patients referred to a general dermatology clinic were seen by both a "live" dermatologist and a "teledermatologist" via a T1 connection. Diagnosis and recommendations were recorded by both physicians and compared. The physicians were also asked to rate the degree of confidence they had in their diagnosis.

RESULTS

Seventy-nine diagnoses were made on 60 patients. The two physicians were in absolute agreement on 61 of the diagnoses (77.2%). Race or sex of the patient, nature of the skin problems, or which of the two physicians was the teledermatologist did not statistically correlate with the concordance of the two physicians.

CONCLUSION

There was a reasonable degree of agreement between the two examining physicians. Despite the relatively high degree of concordance the teledermatologist had a significantly lower degree of confidence in his diagnoses.

Two teenagers, traumatic aortic disruption, and transoesophageal echocardiography

A report of two teenagers is presented who were passengers of the same vehicle when it was involved in a serious road traffic accident. Their vehicle was hit on the side at high speed by a second vehicle. Both teenagers sustained multiple injuries. On arrival at a district general hospital they required resuscitation, exploratory laparotomies, and postoperative intensive care. Neither had radiographic evidence to suggest any mediastinal injury, but transoesophageal echocardiography demonstrated aortic disruption in both patients. They were transferred to a regional cardiothoracic centre where their lesions were successfully repaired and both have made a full recovery.

A GPI-linked protein that interacts with Ret to form a candidate neurturin receptor

Glial-cell-line-derived neurotrophic factor (GDNF) and neurturin (NTN) are two structurally related, potent survival factors for sympathetic, sensory and central nervous system neurons. GDNF mediates its actions through a multicomponent receptor system composed of a ligand-binding glycosyl-phosphatidylinositol (GPI)-linked protein (designated GDNFR-alpha) and the transmembrane protein tyrosine kinase Ret. In contrast, the mechanism by which the NTN signal is transmitted is not well understood. Here we describe the identification and tissue distribution of a GPI-linked protein (designated NTNR-alpha) that is structurally related to GDNFR-alpha. We further demonstrate that NTNR-alpha binds NTN (K[d] approximately 10 pM) but not GDNF with high affinity; that GDNFR-alpha binds to GDNF but not NTN with high affinity; and that cellular responses to NTN require the presence of NTNR-alpha. Finally, we show that NTN, in the presence of NTNR-alpha, induces tyrosine-phosphorylation of Ret, and that NTN, NTNR-alpha and Ret form a physical complex on the cell surface. These findings identify Ret and NTNR-alpha as signalling and ligand-binding components, respectively, of a receptor for NTN and define a novel family of receptors for neurotrophic and differentiation factors composed of a shared transmembrane protein tyrosine kinase and a ligand-specific GPI-linked protein.

Natural history and management of the asymptomatic, moderately stenotic internal carotid artery

PURPOSE

Although it has been widely accepted as the evidence supporting prophylactic carotid endarterectomy, aspects of the Asymptomatic Carotid Atherosclerosis Study have left unease among clinicians who must decide which individuals without symptoms should undergo surgery. Additional confusion has been created by the fact that the several large randomized trials investigating the efficacy of carotid endarterectomy have classified and analyzed different categories of carotid stenosis. In an effort to provide more information on the natural history of asymptomatic, moderate carotid artery stenosis (50% to 79%), we have reviewed data on approximately 500 arteries.

METHODS

Records of our vascular laboratory from 1990 to 1992 were reviewed. We identified 425 patients with asymptomatic, moderate carotid artery stenosis; 71 patients had bilateral stenoses in this category, resulting in 496 arteries for study.

RESULTS

The mean length of follow-up was 38 +/- 18 months. New ipsilateral strokes occurred in 16 (3.8%) patients. New ipsilateral transient ischemic attacks occurred in 25 (5.9%) patients. Documented progression of stenosis occurred in 48 (17%) of the 282 arteries for which a repeat duplex examination was available. Arteries that progressed to > 80% stenosis were significantly more likely to have caused strokes than those that remained in the 50% to 79% range (10.4% vs 2.1%, p < 0.02). Conversely, arteries that remained stable in the degree of stenosis were significantly more likely to have remained asymptomatic than those that progressed (92.7% vs 62.5%, p < 0.001). With life-table analysis the estimated cumulative ipsilateral stroke rate was 0.85% at 1 year, 3.6% at 3 years, and 5.4% at 5 years. The respective estimated cumulative transient ischemic attack rates were 1.9%, 5.5%, and 6.3%. The respective estimated cumulative rates for progression of stenosis were 4.9%, 16.7%, and 26.5%. Life-table comparison of ipsilateral stroke revealed a significantly higher cumulative rate among arteries that progressed in the degree of stenosis than among those that remained stable (p < 0.001).

CONCLUSIONS

Based on the low rate of permanent neurologic events in these cases, prophylactic carotid endarterectomy for the asymptomatic, moderately stenotic internal carotid artery cannot currently be recommended. The only factor that appears to predict increased risk for future stroke is progression of stenosis. Careful follow-up with serial repeat duplex examinations must be performed in these patients. Until there are widely accepted duplex parameters that can provide all clinicians with accurate identification of arteries with narrowing corresponding to 60% stenosis as defined by the Asymptomatic Carotid Atherosclerosis Study, all surgeons will need to be aware of specifically how their noninvasive laboratories are deriving their results. For the many laboratories that continue to use the University of Washington criteria, 80% should remain the level above which prophylactic carotid endarterectomy is warranted.

A randomized cross-over study comparing the use of a catheter valve and a leg-bag in urethrally catheterized male patients

OBJECTIVES

To evaluate the use of a catheter valve (CV) and a leg-bag (LB) in men with urethral catheters and to determine the preferred modality.

PATIENTS AND METHODS

Eighteen men (mean age 71.4 years, SD 3.4, range 63-76) presenting in acute retention and catheterized urethrally were enrolled in a 6-week randomized cross-over study comparing the CV with the LB (3 weeks with each modality). The outcome was assessed using a questionnaire which quantified the incidence of bladder spasms, nocturnal frequency, the extent of any by-passing episodes and the degree of discomfort. At the end of the study, the patients were asked to express a preference (using a subjective scoring scale) for either the CV or the LB and to give the reasons why.

RESULTS

There was no difference in the reported incidence of bladder spasms or discomfort and no difference in positive urine cultures with each modality. However, with the CV, there was a slightly higher incidence in nocturnal frequency and by-passing episodes. Thirteen patients preferred the CV whilst five preferred the LB. With the subjective scoring scale (range 0-10), the CV scored significantly higher than the LB (7.2, SD 3.1 and 5.2, SD 2.8, P < 0.05: paired t-test).

CONCLUSIONS

Most patients preferred to use the CV, reporting that it felt more comfortable and discreet, and many patients did not like the sensation of urine 'sloshing about' when using the leg-bag. Some patients using the CV were troubled by nocturnal frequency. In these patients we suggest that a combination of a valve during the day and an overnight bag may be the ideal solution.

Supraoccluding cobalt-chrome onlays in the management of amelogenesis imperfecta in children: a 2-year case report

Children suffering from the inherited dental anomaly amelogenesis imperfecta frequently present with sensitive, discolored teeth and decreased lower facial height. The aim of treatment is to reduce sensitivity while maintaining the maximum amount of hard tissue possible until the patient reaches an age at which advanced restorative techniques can be used to rehabilitate the dentition. A case is presented in which amelogenesis imperfecta in the mixed dentition was managed by the placement of adhesive cast restorations. These restorations have been in place for 2 years.

Characterization of familial partial 10p trisomy by chromosomal microdissection, FISH, and microsatellite dosage analysis

Unbalanced translocations are a frequent cause of multiple congenital anomalies in children. Translocations as small as 2-5 Mb of DNA are detectable by G-banding under optimal conditions. Some of these small translocations are visible but cannot be characterized cytogenetically due to the lack of characteristic banding on Giemsa preparations. We have combined chromosomal microdissection and fluorescence in situ hybridization (FISH) to identify the origin of a small translocated segment in three members of a family with a derivative chromosome 9 and multiple anomalies, including several ophthalmologic anomalies. We microdissected the abnormal region of the derivative 9 chromosome and used this DNA to generate a FISH probe. This probe hybridized to distal 10p on the metaphase spread of the proband, indicating the origin of the translocated segment. A whole 10p FISH probe confirmed the origin by hybridizing to the translocated segment of the derivative chromosome. FISH was then performed with a whole chromosome 9 painting probe and excluded the presence of a reciprocal, balancing translocation. We then studied the chromosome 10 partial duplication with microsatellite markers to better characterize the chromosomal segment that caused these phenotypic features. By examining the involved areas with distal 10p and 9p microsatellite markers, we were able to demonstrate a minimum of 9 Mb of trisomic 10p DNA with a chromosomal breakpoint between 10p14-10p15. We then compared this family's clinical findings to those of individuals with partial 10p trisomy who had been reported in the literature. The clinical phenotypes seen in this family are similar to, but milder than, the phenotypes of persons with the larger partial trisomies of 10p that were diagnosable by cytogenetic analysis alone. This study shows that microdissection and DNA markers can be used to precisely define small translocations that are difficult to identify by conventional G-banded chromosome analysis.

Human (THP-1) macrophages oxidize LDL by a thiol-dependent mechanism

The oxidative modification of low-density lipoprotein by macrophages may be an important mechanism in the pathogenesis of atherosclerosis. The human monocytic leukaemic cell line THP-1, when stimulated with phorbol ester, shares many properties with human monocyte-derived macrophages. Oxidation of LDL by these cells was characterised by depletion of alpha-tocopherol, increases in thiobarbituric acid reactive substances and increases in electrophoretic mobility. The LDL particles were also converted to a form which increased accumulation of cholesteryl esters within macrophages. The oxidative mechanism appeared to be dependent upon the presence of thiols in the cellular medium. Oxidation of LDL by THP-1 macrophages, and production of thiols by these cells, were dependent upon the presence of L-cystine in the medium. Furthermore, cellular oxidation of LDL could be partially mimicked by the addition of cysteine to Hams F10 medium. Macrophage-independent oxidation of LDL, mediated by the addition of copper ions, was inhibited by cystine and cysteine in phosphate buffered saline, but not in Hams F10 medium. The glutathione content of THP-1 macrophages was also dependent upon the presence of cysteine or cystine in the medium, but inhibition of glutathione synthesis by buthionine sulfoximine did not prevent the production of thiols or the oxidation of LDL by THP-1 macrophages.

Role of lipid hydroperoxides in the activation of 15-lipoxygenase

We have used stopped-flow rapid reaction methods, employing both fluorescence and absorbance monitoring, together with HPLC analysis of the products to study the activation of soybean 15-lipoxygenase by 13(S)-hydroperoxy-9, 11(E,Z)-octadecadienoic acid (13-HPOD). When lipoxygenase is mixed with an equimolar concentration of 13-HPOD, the enzyme undergoes a rapid change in fluorescence. The rate of the change of fluorescence is dependent on the concentration of the 13-HPOD (k = 6.7 x 10(6) M-1 s-1) and is accompanied by activation of the enzyme. The fluorescence change is not accompanied by any change in the UV absorbance of the 13-HPOD, suggesting no loss of the conjugated diene during enzyme activation, and HPLC analysis of the products of the reaction confirms that the 13-HPOD can be recovered unchanged following this reaction. In the presence of an inhibitor (BWA4C, a hydroxamate inhibitor) that reduces the active-site iron, the 13-HPOD and the inhibitor are destroyed in a peroxidase-like reaction. On the basis of these observations we propose that 13-HPOD binds to the enzyme and facilitates activation of the enzyme, possibly through the formation of a protein radical, and that the 13-HPOD is not changed chemically in this process.

Stimulation of mitochondrial oxygen consumption in isolated cardiomyocytes after hypoxia-reoxygenation

An increase in mitochondrial matrix free calcium has been shown to occur during oxygen and substrate deprivation of the perfused heart which predisposes to calcium overload and inhibition of mitochondrial function on reoxygenation. In the current study we have assessed the effect of substrate free hypoxia on mitochondrial oxygen consumption and ATP synthesis in isolated rat cardiomyocytes. Myocytes were subjected to 40 min of substrate-free hypoxia and the oxygen consumption measured together with the effects on ATP and PCr synthesis. After hypoxia myocytes showed a fall in ATP to 10% of the control value. Within 5 sec of reoxygenation the ATP level recovered to a new steady state level of 30% of the original value. The rate of oxygen consumption of hypoxic/reoxygenated cells was 3-4 fold higher than that of cells maintained under normoxic controls but in the presence of oligomycin the difference was only 1.5-fold higher, indicating a greater requirement for mitochondrial synthesis of ATP following reoxygenation. Reoxygenation in the absence of extracellular Ca2+ resulted in a lower rate of oxygen consumption (50% of the rate measured in the presence of 1 mM-Ca2+) but did not affect the steady state concentration of ATP attained 5 min after reoxygenation. These results support the idea that the increased O2 consumption of myocytes following hypoxia/reoxygenation is due to an increased demand for ATP synthesis by mitochondria and is a response to the NA+ and Ca2+ loading of the cells which occurs under these conditions. This increased demand is likely to result in a greater generation of free radicals such as superoxide by the respiratory chain which could impair cellular function over the long term.

The resistance of low density lipoprotein to oxidation promoted by copper and its use as an index of antioxidant therapy

The measurement ex vivo of the resistance of low density lipoprotein (LDL) to oxidation promoted by copper is now being used in surveys of human populations at risk of developing atherosclerosis. However, it is not known whether a relationship between LDL oxidisability measured in this way and the development of atherosclerotic lesions exists. Using Watanabe rabbits as a model of the disease, we have found that dietary supplementation with the antioxidants, probucol and alpha-tocopherol, increased the resistance of LDL isolated from small volumes of plasma to oxidation. The antioxidant effects of probucol incorporated into LDL through dietary supplementation were greater than when incorporated ex vivo. When dietary supplementation was extended to a period of three months, the well established anti-atherosclerotic effects of probucol were confirmed and a highly significant relationship between the probucol content of the LDL particle and the extent of the atherosclerotic lesion in the aorta emerged. These results suggest that the assessment of the resistance of LDL isolated from plasma to oxidation promoted by copper may reflect the response of the arterial atherosclerotic process to antioxidant therapy.

The role of an agrin-growth factor interaction in ACh receptor clustering

The clustering of acetylcholine receptors (AChRs) at the neuromuscular junction is mediated in part by the heparan-sulfate proteoglycan agrin. However, our previous studies have also suggested the role of heparin-binding growth-associated molecular (HB-GAM) in AChR clustering. Here the role of an agrin-HB-GAM interaction in this process was examined using cultured Xenopus muscle cells. Agrin-coated beads further treated with HB-GAM were highly effective in AChR cluster induction. Protein overlay assays showed specific binding of HB-GAM to agrin. In addition, agrin-enriched neuritic tracks bound HB-GAM in a manner that showed a high degree of colocalization between the neural agrin and the applied factor. Finally, the introduction of exogenous HB-GAM together with soluble agrin resulted in the appearance of AChR clusters on the dorsal surface of cells in an agrin isoform-dependent manner; a dramatic change from the characteristic ventral AChR clustering seen in response to agrin alone. These results suggest that agrin may mediate AChR clustering by interacting with muscle-bound heparin-binding growth factors such as HB-GAM.

Full-length agrin isoform activities and binding site distributions on cultured Xenopus muscle cells

Agrin is a large multidomain protein involved in the induction of postsynaptic differentiation of the neuromuscular junction. As a step toward further understanding the mechanisms by which agrin induces the aggregation of acetylcholine receptors (AChRs), we have characterized the activity of purified, full-length chick agrin isoforms on Xenopus muscle cells. Incubation with agrin isoforms led to the formation of numerous small AChR clusters primarily on the ventral surface of cells with differing efficacies: Y4Z8 > Y4Z11 = Y4Z19, with Y4B0 being ineffective. Agrin activity appeared to be tyrosine phosphorylation-dependent as the kinase inhibitor tyrphostin RG50864 (80 microM) completely abolished the effect. Initial binding sites for all agrin isoforms were evenly distributed in a punctate manner on the muscle cell surface. After a 14-h incubation, the active isoforms induced AChR clustering, and agrin was enriched at these sites of clustering. Agrin binding to the cell surface and induction of AChR clustering were Ca(2+)-dependent, as previously shown in other systems. This is the first quantitative characterization of agrin's effects using Xenopus cell culture, providing a basis for further elucidating agrin's role in synaptogenesis using this elegant system.

Screening in Scotland

A survey of screening in Scottish Health Boards suggests that, with the exceptions of screening in the antenatal period, for some conditions in the neonatal period and for the two national programmes for breast and cervix in adult women, practice is by no means uniform across all Boards and there is a lack of systematic evaluation. Four suggestions are made to improve equity, quality and relevance of screening: (i) national guidelines should be formulated to promote the implementation of the same core screening activities in all Boards; (ii) audit and quality control programmes should be universal and systematically applied; (iii) the demarcations of professional and managerial responsibilities and lines of accountability should be clarified; (iv) any proposed new screening programmes should be assessed in the light of the World Health Organisation principles before their introduction.

Home alone: is it a risk factor for middle school youth and drug use?

This study examined the relationship between middle school/junior high student latchkey status and early experimentation and use of alcohol, tobacco, and other drugs. Students were queried about the frequency (number of times per week) and quantity (number of hours per day) of unsupervised after school days in an average week. Questions were also asked regarding their experiences with "gateway" drugs, inhalants, and steroids. Chi square analysis was used to test the strength of association. The results of this study indicated that latchkey youth (LKY) who were home alone two or more days per week were four times more likely to have gotten drunk in the past month than those youth who had parental supervision five or more times a week. Also, significant differences were observed for LKY with respect to cigarette smoking, inhalants, and marijuana use. Other findings and demographic variables were discussed as they pertain to LKY as well as suggested strategies for healthy self-care alternatives.

Oxidation of human low-density lipoprotein by soybean 15-lipoxygenase in combination with copper (II) or met-myoglobin

The enzyme 15-lipoxygenase has been implicated in the oxidation of low-density lipoprotein (LDL) in human atherosclerotic lesions. The biochemical mechanism for this oxidative process is not fully understood, and the interaction of the lipoxygenase-modified lipoprotein with metals or metalloproteins has not been explored. In the present study we have used soybean lipoxygenase to model the interaction of the enzyme with LDL and show that a direct oxygenation of fatty acids occurs, including those esterified to cholesterol, with no lag phase or change in electrophoretic mobility of the LDL particle but with some depletion of alpha-tocopherol. The enzyme-dependent oxidation may involve propagation through the release of peroxyl radicals from its active site but appears to have no requirement for free iron or copper. When lipoxygenase-treated LDL is exposed to either copper (II) or metMb, a rapid oxidation process occurs, resulting in a marked decrease in resistance to oxidation and an increase in the rate of modification to a form with increased electrophoretic mobility. This effect was not seen if lipoxygenase-treated LDL was oxidized by SIN-1, a peroxynitrite donor that oxidizes LDL with no requirement for endogenous lipid hydroperoxides. We propose that a synergistic interaction may occur between the peroxides inserted into LDL as a consequence of the enzymatic action of lipoxygenase with haem proteins or copper, which decreases the potency of the endogenous antioxidants and enhances oxidation.