Cutaneous melanoma mortality among the socioeconomically disadvantaged in Massachusetts

OBJECTIVES

To identify groups for melanoma prevention and early detection programs, this study explored the hypothesis that survival with cutaneous melanoma is disproportionately lower for persons of lower socioeconomic status.

METHODS

Massachusetts Cancer Registry and Registry of Vital Records and Statistics data (1982 through 1987) on 3288 incident cases and 1023 deaths from cutaneous melanoma were analyzed. Mortality/incidence ratios were calculated and compared, predictors of late stage disease were examined with logistic regression analysis, and a proportional hazards regression analysis that used death registration as the outcome measure for incident cases was performed.

RESULTS

Lower socioeconomic status was associated with a higher mortality/incidence ratio after adjustment for age and sex. For education, the mortality/incidence ratio was 0.37 in the lower group vs 0.25 in the higher group (rate ratio = 1.48, 95% confidence interval [CI] = 1.08, 2.03). Late stage disease was independently associated with lower income (rate ratio for lowest vs highest tertile = 1.64, 95% CI = 1.20, 2.25), and melanoma mortality among case patients was associated with lower education (rate ratio = 1.52, 95% CI = 1.09, 213).

CONCLUSIONS

Melanoma patients of lower socioeconomic status may be more likely to die from their melanoma than patients of higher socioeconomic status. Low- SES communities may be appropriate intervention targets.

Glucoprivation counteracts effects of testosterone on daily torpor in Siberian hamsters

We tested whether 1) glucose availability is a signal for initiation of torpor in male hamsters and 2) glucoprivation can override the inhibitory effects of androgens on daily torpor. Male hamsters maintained at ambient temperatures of 8-16 degrees C were injected with 2-deoxy-D-glucose (2DG), a glucose analogue that interferes with cellular glucose oxidation. 2DG (2,000-2,500 mg/kg body mass) induced torpor within 1 h of treatment in normal adult males in reproductive condition and in those bearing testosterone (T)-filled capsules that produced supraphysiological blood T concentrations; body temperatures were reduced from 37 to 25 degrees C for several hours. Latency to torpor was increased and duration of torpor was decreased in the T-treated hamsters. Food intake decreased substantially both on the day of torpor and on the succeeding day. Glucoprivation appears to counteract the potent inhibitory effect of androgens on torpor and induces a hypometabolic state that results in overall energy savings.

Periodontitis in the baboon: a potential model for human disease

Advances in periodontics with respect to disease activity, microbiology and immunology have demonstrated the multifactorial nature of periodontal diseases. This serves to underscore the need for an ideal animal model for periodontal research. Non-human primates are most similar to man in comparison to other animal models. The baboon is an Old World monkey that has infrequently been used in periodontal research. Periodontal exams were accomplished on 116 baboons (Papio anubis, P. cynocephalus) ages 5 to 30 years with one baboon year being roughly equivalent to 3 to 4 human years. The study population consisted of 29 males and 87 females. Clinical parameters including probing depth, attachment level, mobility, plaque index and gingival index were collected. Radiographs were taken on 25 animals and correlated to clinical findings. Results showed a significant increase in mean probing depth and mean attachment level with age (p = 0.0001). Disease prevalence and severity were not significantly different between genders. Mobility was uncommon; however, the prevalence and severity of furcation involvement increased with age. Radiographs suggested horizontal and isolated vertical bone loss. Plaque and gingival indices were at sustained high levels for all age groups and showed a statistically significant increase with age. Some baboons were found to develop a naturally-occurring periodontitis that increased in severity with age. This primate may be a suitable model for studies in human periodontal disease.

Edrophonium requirements for reversal of deep neuromuscular block following infusion of mivacurium

Mivacurium is a new non-depolarizing muscle relaxant consisting of three stereoisomers. The two active isomers (cis-trans and trans-trans) undergo rapid metabolism by plasma cholinesterase (t1/2 beta < 2 min). Due to its rapid elimination, the need for reversal of mivacurium-induced neuromuscular block is controversial, and to date there have been no studies evaluating reversal of deep blocks. The object of the current investigation was to establish the lowest effective dose of edrophonium required to reverse deep mivacurium-induced neuromuscular block. One hundred ASA Class I and II patients undergoing outpatient surgery in two teaching institutions were studied in this randomized, placebo-controlled double-blind trial. Under balanced propofol/nitrous oxide/alfentanil anaesthesia, a continuous infusion of mivacurium was adjusted to maintain between 5-10% of control T1 amplitude. Upon completion of surgery, neuromuscular block was reversed by injecting normal saline (Group PLAC), edrophonium 0.125 mg.kg-1 (Group EDR-1), 0.25 mg.kg-1 (Group EDR-2), or 0.50 mg.kg-1 (Group EDR-3), in addition to a corresponding dose of atropine. Spontaneous recovery, from a T1 response of < 10% to a TOF ratio > or = 0.7, required 13.5 +/- 2.6 min (PLAC Group). In comparison, patients in the EDR-1 group required 9.2 +/- 2.6 min (P < 0.01). Higher doses of edrophonium conferred no advantage. Four patients (4%) had not achieved a TOF ratio of > or = 70%, 20 min after reversal, and required additional edrophonium. Two patients (PLAC group), had dibucaine numbers and cholinesterase levels consistent with an EUEA genotype, whereas the two patients with delayed recovery in the EDR-1 group had characteristics of a normal genotype. We conclude that a very low dose of edrophonium (0.125 mg.kg-1) hastens reversal of deep mivacurium-induced neuromuscular block by approximately four minutes, and that edrophonium doses exceeding 0.125 mg.kg-1 provide no additional benefit. Heterozygous patients with atypical plasma cholinesterase levels, as well as certain individuals with normal dibucaine numbers and plasma cholinesterase activity, are at risk for prolonged neuromuscular block, but the block is easily reversed with edrophonium.

The current status of melanoma early detection and screening

Multiple strategies are required to combat the increasing incidence and mortality of cutaneous melanoma. Major questions about melanoma and skin cancer are reviewed, with particular attention to education and early detection.

Clinical effect of converting antidepressant therapy from fluoxetine to sertraline

The effect of replacing fluoxetine with sertraline at two dosage-conversion ratios was studied. Outpatients at a Veterans Affairs mental health clinic who were being treated with fluoxetine were randomly assigned to receive either 50 or 75 mg of sertraline hydrochloride for every 20 mg of fluoxetine (as the hydrochloride salt) or to continue to receive their current dosage of fluoxetine. The subjects were given the Hamilton Depression Rating Scale (HDRS) and the Beck Depression Inventory (BDI) at baseline and were re-examined at one-month intervals for three months with the HDRS and BDI and the Clinical Global Impression of Change. Each patient was re-evaluated by the same blinded investigator. A total of 45 patients (42 men and 3 women) completed the study. The final overall response did not differ significantly among the three groups. There were also no significant differences among the groups in the proportions of patients with HDRS and BDI scores classified as improving, worsening, or not changing. Improvement was more common in patients receiving the higher dosage of sertraline. Few adverse effects were reported. Outpatients receiving fluoxetine were switched to sertraline therapy without a loss of control of depression and without substantial adverse effects.

The early detection of and screening for melanoma. International status

Cutaneous melanoma is an increasingly common public health problem in industrialized nations. In theory, education and early detection should decrease melanoma morbidity and mortality, because the lesion is external and visible, risk factors are known, and thin tumors are associated with a high 5-year survival rate. The efficacy of early detection and screening programs, however, remains untested by randomized trials. Some early data are available from melanoma prevention and control efforts that have begun in many nations over the past decade. Textbook definitions of cancer screening are particularly challenging when applied to skin cancer control. Although some propose that there are rigid differences among screening, education, and early detection of skin cancer, the visible nature of this cancer makes early detection through education and screening inextricably intertwined. This article discusses the intermediate measures of education and screening within the context of the American Academy of Dermatology programs. Over the next few decades, screening and education for melanoma and other skin cancer will receive increasing worldwide attention. Multiple strategies will be required to combat increasing incidence and mortality rates. Screening and educational programs have been implemented worldwide, but data on their effects are only just being collected. Future collaborative work in melanoma/skin cancer prevention, education, and early detection holds promise as a way to decrease mortality and save lives.

Optimizing sedation following major vascular surgery: a double-blind study of midazolam administered by continuous infusion

A randomized, double-blind study was undertaken to determine the dose requirements, recovery characteristics, and pharmacokinetic variables of midazolam given by continuous infusion for sedation in patients following abdominal aortic surgery. Thirty subjects, 50-75 yr, scheduled to undergo aortic reconstructive surgery, entered the study. Following a nitrous oxide-isoflurane-opioid anaesthetic technique, patients were randomly allocated to receive one of three loading doses (0.03, 0.06 or 0.1 mg.kg-1) and initial infusion rates (0.5, 1.0 or 1.5 micrograms.kg-1.min-1) of midazolam, corresponding to groups low (L), moderate (M) and high (H). The infusion of midazolam was adjusted to maintain sedation levels of "3, 4 or 5," which permitted eye opening in response to either verbal command or a light shoulder tap, using a seven-point scale ranging from "0" (awake, agitated) to "6" (asleep, non-responsive). Additionally morphine was given in increments of 2.0 mg iv prn for analgesia. On the morning after surgery, midazolam was discontinued, and the tracheas were extubated when patients were awake. Blood samples were taken during, and at increasing intervals for 48 hr following discontinuation of the infusion, and analyzed by gas chromatography. The desired level of sedation was maintained during more than 94% of the infusion period in all three groups, with a maximum of three dose adjustments per patient, for treatment which lasted 16.3 +/- 0.6 hr. There was, however, an increase in both the infusion rates and mean plasma concentrations from Group L to Group H (P < 0.05), which corresponded to an inverse relationship of morphine requirements during the period of sedation (P < 0.05, Group H vs Group L). Optimal midazolam infusion rates and resulting plasma concentrations at the times the infusions were discontinued (in parentheses) were as follows-Group L: 0.60 +/- 0.18 microgram.kg-1.min-1 (76 +/- 32 ng.mL-1), Group M: 0.90 +/- 0.52 microgram.kg-1.min-1 (133 +/- 71 ng.mL-1), and Group H: 1.34 +/- 0.69 microgram.kg-1.min-1 (206 +/- 106 ng.mL-1). Times to awakening were longer in Group H: 3.1 +/- 3.4 hr, than in Group L: 1.1 +/- 0.8 h, P < 0.05. Pharmacokinetic variables were found to be dose-independent over the range of infusion rates. Mean values were t1/2 beta = 4.4 +/- 1.5 hr, CL = 5.94 +/- 1.69 mL.min-1.kg-1, Vd = 3.13 +/- 1.07 L.kg-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Reduced glucose availability induces torpor in Siberian hamsters

Siberian hamsters kept in long photoperiods (16 h light/day) at 10 degrees C do not display torpor when provided with food ad libitum but do reduce their body temperatures (Tb) from 37 degrees C to as low as 15 degrees C for several hours each day in response to food restriction. Female hamsters maintained in a long photoperiod and fed ad libitum were injected with 2-deoxy-D-glucose (2-DG), a glucose analogue that reduces cellular glucose oxidation, or mercaptoacetate (MA), a drug that disrupts fatty acid oxidation. Dosages of 2-DG in excess of 1,500 mg/kg body mass reliably induced torpor with latencies of approximately 50 min from time of injection to a decrease in Tb below 30 degrees C; 79% of females displayed torpor at a dosage of 2,500 mg/kg. MA was uniformly ineffective in inducing torpor and did not increase incidence of torpor when combined with 2-DG treatment or food restriction. Decreased availability of glucose may be the major metabolic signal for inducing torpor in Siberian hamsters; availability of fatty acids appears to play little if any role in regulating this behavior.

Intravenous infusion anaesthesia and delivery devices

During the past decade, major advances have taken place with regard to intravenous infusion anaesthesia. New opioid analgesics, iv anaesthetics, and muscle relaxants have become available, which are characterized by a rapid onset of action, short duration of clinical effect, and favourable side effect profiles. Optimal administration of these drugs is often best achieved by continuous infusion, rather than a more traditional technique of intermittent bolus administration. New concepts in pharmacokinetic modelling also provide an enhanced appreciation of the factors which determine rates of recovery upon discontinuation of an intravenous infusion. Pharmacokinetic principles guide rational selection of the iv anaesthetic drugs according to both procedure and patient-specific requirements. In addition, improvements in the new programmable syringe infusion pumps provide a degree of simplicity and accuracy in operation, which make iv infusion of one, two or three components of the anaesthetic state a simple and practical reality for most procedures. In this CME article, these issues will be reviewed according to the following outline: Historical considerations; Rationale for continuous infusion of iv anaesthetic drugs; Pharmacokinetic and pharmacodynamic considerations; Infusion schemes; New techniques, new indications; IV anaesthetic delivery systems; Pharmacoeconomic considerations; Conclusions.

Impaired neurite outgrowth of src-minus cerebellar neurons on the cell adhesion molecule L1

The nonreceptor tyrosine protein kinases pp60c-src, p59fyn, and pp62c-yes are localized in growth cones of developing neurons, but their function is undefined. To determine whether these tyrosine kinases were capable of regulating substrate-dependent axon growth, cultures of cerebellar neurons from wild-type, src-, fyn-, and yes- mice were analyzed for neurite outgrowth on the neural cell adhesion molecule L1 or the extracellular matrix protein laminin. The rate of neurite extension on L1 was reduced in src-, but not in fyn- or yes- neurons. Neurite extension on laminin was unaltered in src-, fyn-, or yes- neurons, indicating that pp60c-src, p59fyn, or pp62c-yes is not likely to participate in integrin-dependent axon growth. These results demonstrate that pp60c-src is a component of the intracellular signaling pathway in L1-mediated axonal growth and suggest that Src-related nonreceptor tyrosine kinases may have distinct, nonredundant functions in the nervous system.

Absence of a reservoir of Epstein-Barr virus (EBV) in normal tongue epithelium

We examined human tongue epithelium and serum samples at autopsy for evidence of latent Epstein-Barr virus (EBV) infection. Although clinical serology revealed anti-EBV antibodies in most sera indicating past EBV infection, we found no Epstein-Barr nuclear antigen (EBNA)-coding sequences in tongue tissue by polymerase chain reaction (PCR), or Epstein-Barr-encoded RNA (EBER1) by in situ hybridization. Tongue epithelium does not appear to be a natural reservoir for latent EBV in immunocompetent hosts.

A cross-national investigation of diet and bladder cancer

The existence of a large unexplained portion of attributable risk, and the marked variation in bladder cancer rates globally, have stimulated an interest in the role of nutrition in cancer of the urinary bladder. For this cross-national comparison study, we had complete data available for 50 countries. Using stepwise regression followed by general linear modelling, age-truncated (45-74 years), world-standardised, sex-specific bladder cancer mortality rates were regressed on an array of nutritional and socioeconomic independent variables in an effort to identify important predictors of bladder cancer mortality. Separate principal components analyses were used to summarise the nutritional and the socioeconomic (SES) variables. In the stepwise analyses, using food scores expressed in kcal/day per capita (as opposed to the nutritional components), total fat consistently entered the model first, and explained the greatest share of variability (R2) for both males and females. General linear models were fitted that included total fat, tobacco, alcohol, the three SES components (comprising seven socioeconomic predictors) and two food categories found significant in stepwise modelling, roots/tubers and vegetable oil. The R2 values were 0.84 for male rates and 0.77 for female rates, meaning that these study factors account for 84% of bladder cancer mortality in men and 77% in women. Substitution of the nutritional components for the foods resulted in general linear models with slightly higher R2 values (0.85 for males, 0.77 for females), but with attenuated fat effects. Results are discussed in light of biological plausibility.

Treatment of overt isolated testicular relapse in children on therapy for acute lymphoblastic leukemia. A report from the Childrens Cancer Group

BACKGROUND

Fifty-seven children with acute lymphoblastic leukemia (ALL) receiving therapy who experienced overt isolated testicular relapse while in bone marrow remission were entered into a study that featured an intensive retreatment regimen.

METHODS

The objective was to determine whether a change in chemotherapy and local irradiation would prevent subsequent marrow relapse and increase the survival rate. The regimens used (modified Berlin-Frankfurt-Munster or modified New York) delivered acceptable therapy based on analyses of toxicity data.

RESULTS

Overall survival at 5 years from the time of testicular relapse was 47%, with an event-free survival of 43%. Events have been documented in 28 of 55 evaluable children. Analysis of these patients revealed that 23 children had bone marrow relapse, 4 children had central nervous system relapse, and 1 child had testicular relapse. In addition, two patients were removed from the study for toxicity, one child for infection (mucormycosis), and five children had a bone marrow transplantation while in remission and became ineligible to continue in the study. Two children were removed at the request of their parents, and nine children were lost to follow-up.

CONCLUSION

Because of their high risk of developing systemic relapse, boys with ALL who experience isolated overt testicular relapse during active therapy should be retreated with intensive treatment.

Use of serotonergic drugs for treating depression in older patients

The selective serotonin reuptake inhibitors (SSRIs) offer a relatively new alternative to traditional tricyclic antidepressants (TCAs) in the treatment of depression in older adults. The two drug classes are equally effective, but SSRIs tend to cause fewer sedating, anticholinergic, or hypotensive effects and are unlikely to affect cardiac conduction. SSRIs also have a wider therapeutic window and are safer in cases of overdose. Potential side effects include GI distress, worsening of headaches, insomnia, and sexual dysfunction. Drawbacks of using SSRIs are their potential for drug interactions and relatively high cost.

Variation in condensation pressure during clinical packing of amalgam restorations

Clinical measurements were made of the condensation pressures applied by a specialist prosthodontist to each amalgam increment during the packing of two pinned Class II restorations. The technique employed involved taking simultaneous video recordings of the operative procedures and the output of a strain gauge stress measuring system attached to the plugger. The condensation pressure applied during each thrust of the plugger could then be related directly to a particular stage of the packing process. In Cavity A, a maxillary left second premolar, an "admix" amalgam containing both spherical and lathe-cut particles was used while Cavity B, a mandibular right first molar, was filled with a spherical particle amalgam. The measurements indicated that the condensation pressures applied decreased substantially as the filling of each cavity proceeded. A marked reduction accompanied the change from a 1.5 mm diameter to a 2.5 mm diameter plugger but in addition, the dentist modified the force applied to each plugger according to the particular task which he was undertaking. For Cavity A, the condensation pressure applied during the filling of the base of the mesial proximal box was 12.6 +/- 1.9 MPa whereas the final increment was subjected to a condensation pressure of only 2.2 +/- 0.7 MPa. Corresponding figures for Cavity B were 7.6 +/- 2.0 MPa and 1.9 +/- 0.5 MPa.

Alloy particle shape and sensitivity of high-copper amalgams to manipulative variables

Compressive strength, dimensional change during hardening and residual mercury content of three high-copper spherical particle amalgams (Tytin, Logic and Valiant), two admix amalgams (Dispersalloy and Permite C) and a conventional lathe-cut amalgam (New True Dentalloy) were determined as a function of condensation pressure and trituration time. The properties of the three amalgams containing non-spherical particles were markedly dependent on condensation pressure in the range 3 MPa to 14 MPa. Specimens condensed at 3 MPa showed substantially lower strength, greater expansion during hardening and higher residual mercury contents than did specimens condensed at 14 MPa. The three high-copper spherical particle amalgams, on the other hand, were comparatively insensitive to condensation pressure. Variations in trituration time between 5 and 12 seconds had little effect on the properties of any of the amalgams.

Nutrition and health risks in the elderly: the nutrition screening initiative

OBJECTIVES

The Nutrition Screening Initiative is a national collaborative effort committed to the identification and treatment of nutritional problems in older persons.

METHODS

A 14-item checklist of characteristics associated with nutritional status was administered to a random sample of Medicare beneficiaries, aged 70 years and older, in New England. Regression analysis was used to derive item weights that would predict poor nutrient intakes and low perceived health status. Sensitivity and specificity values were reviewed to define low, moderate, and high nutritional risk scores.

RESULTS

A revised checklist containing 10 yes/no items was adopted. Scores of 6 or more points defined persons at high nutritional risk. Twenty-four percent of the Medicare population was estimated to be at high nutritional risk according to the checklist. Among those in the high-risk group, 56% perceived their health to be "fair" or "poor" and 38% had dietary intakes below 75% of the recommended dietary allowances for three or more nutrients.

CONCLUSIONS

The Nutrition Screening Initiative Checklist is a brief, easily scored instrument that can accurately identify noninstitutionalized older persons at risk for low nutrient intake and health problems.

Hippocampal interneuron activity in unanesthetized rats: relationship to the sleep-wake cycle

Evoked population spikes and interneuronal discharges were recorded throughout the sleep-wake cycle in hippocampal regions CA1 and dentate gyrus (DG) of ten chronically implanted rats. During quiet wakefulness (QW) and slow-wave-sleep (SWS) (non-theta rhythm states), the primary shock of paired stimuli evoked in CA1 both high amplitude population spikes and multiple interneuron discharges when compared to active wakefulness (AW) and rapid-eye-movement (REM) sleep (theta rhythm states). A second shock was delivered to CA1 afferents 60 ms after the first shock. This second shock evoked a small population spikes during non-theta states, whereas it evoked higher amplitude population spikes in theta states. The second shock also evoked unit interneuron discharges in non-theta states but not in theta states. In the dentate gyrus, identical primary afferent stimulation evoked similar interneuron activity and uniform amplitude population spikes throughout the sleep-wake cycle. In contrast, the secondary shocks evoked a striking potentiation of the field population spike during sleep, SWS and REM sleep compared to AW and OW. Evoked DG interneuron spikes following the second population spike were greater in number during SWS compared to the other stages. Our findings suggest that hippocampal field potentials and interneuron activity recorded in vivo are regionally regulated, have unique state-dependent expression and are strongly influenced by inhibitory feed-forward mechanisms.

Ethanol-induced suppression of hippocampal long-term potentiation is blocked by lesions of the septohippocampal nucleus

Systemic ethanol increases synaptic inhibition and suppresses long-term potentiation (LTP) in the dentate gyrus of the rat hippocampus. Local application of ethanol directly into the dentate gyrus of anesthetized rats increased the perforant path to dentate feed-forward inhibition, but had no effect on LTP. Local application of ethanol to the medial septum, a subcortical structure with major input to the dentate, increased recurrent inhibition. Selective disruption of septodentate input produced by lesions of the septohippocampal nucleus blocked the effects of systemic ethanol on LTP. These findings are the first to demonstrate that septodentate input is necessary for ethanol to increase recurrent inhibition and suppress LTP in the dentate gyrus and suggest an important role for extrahippocampal modulation of both short- and long-term plasticity in the hippocampus.

Increased neurite outgrowth induced by inhibition of protein tyrosine kinase activity in PC12 pheochromocytoma cells

Genistein and other inhibitors of protein tyrosine kinases were examined for effects on neurite elongation and growth cone morphology in the rat PC12 pheochromocytoma cell line. Genistein increased the rate of neurite elongation in PC12 cells grown on a collagen/polylysine substratum after priming with nerve growth factor (NGF), but had no effect on undifferentiated cells. Steady-state levels of phosphotyrosine-modified proteins (105, 59, 52, and 46 kDa) were reduced in NGF-primed cells by genistein treatment. The target of genistein action did not appear to be the NGF receptor/trk tyrosine kinase because the presence of NGF in cultures of NGF-primed cells was not necessary for genistein-stimulated neurite outgrowth. The tyrosine kinase inhibitors tyrphostin RG508964 and herbimycin A also increased the rate of neurite elongation in NGF-primed PC12 cells. Video-enhanced differential interference contrast microscopy revealed that growth cones of genistein-treated cells had less complex morphologies and were less dynamic than untreated cells, with short filopodia restricted to the leading edge, unlike untreated cells whose growth cones exhibited longer, more numerous filopodia and lamellipodia, which remodeled continuously. These results suggest that protein tyrosine kinase activity in PC12 cells negatively regulates neurite outgrowth and directly or indirectly affects growth cone morphology.