Energetics and evolution: An emerging research domain

The study of energetics is important to human biology because the availability and utilization of food energy influence health, survival, and reproduction. Over the last decade, human biologists, biological anthropologists, and other evolutionary scientists have increasingly come to recognize the importance of energy dynamics in shaping evolutionary processes. Thus far, different lines of energetics research have been conducted largely in isolation from one another. This thematic collection examines topics of evolutionary energetics from several different perspectives, drawing together research from human paleontology, comparative primate and mammalian biology, human population biology, and mathematical modeling. It represents a starting point for further integrative research on human evolutionary energetics. Am. J. Hum. Biol. 14: 547–550, 2002. © 2002 Wiley‐Liss, Inc.     

Quantitative evaluation of adhesive properties and drug-adhesive interactions for transdermal drug delivery formulations using linear solvation energy relationships.

This paper describes the results of the application of linear solvation energy relationships (LSERs) to quantitatively characterize the properties of adhesives and to evaluate the degree of drug-adhesive interaction in transdermal drug delivery formulations. Probe solutions were prepared in acetonitrile (ACN) for a set of probe compounds with different physicochemical properties, and were used to swell the adhesives for subsequent probe molecule-adhesive interactions. The degree of the interactions was measured by the 'sorbed' amount of probe molecules. Based on LSERs, the 'sorbed' amounts were linearly correlated with their properties. The corresponding coefficients reflect the differential interactions of these molecules with the adhesive and ACN, and are quantitative indications of the adhesive properties. Two different transdermal acrylate adhesives (isooctyl acrylate/acrylamide/vinyl acetate in the weight ratios of 75/5/20 and isooctyl acrylate/2-hydroxyethyl acrylate/vinyl acetate in the weight ratios of 58/20/18) were selected for the evaluation of the methodology. It is concluded that the first adhesive is more basic and hydrophobic, which is consistent with the use of acrylamide monomer and significant amount of isooctyl acrylate. The second adhesive is more acidic and polarizable due to a relatively high amount of the 2-hydroxyethyl acrylate. Additionally, the 'sorbed' amount can be regarded as an interaction parameter or index between a drug molecule and the adhesive. Finally, this parameter is expected to correlate with the thermodynamic properties of transdermal formulations such as drug solubility, diffusion coefficient, release rate, and maybe skin permeation rate.     

Alternative Treatments for Asthma: Assessing the Need

Alternative treatments such as troleandomycin methotrexate, gold, and intravenous gamma globulin are sometimes considered for severe asthmatics to minimize the need for systemic corticosteroids and reduce adverse effects. These alternative therapies may also be associated with significant toxicity and expense. The ability to reduce corticosteroid use and the need for alternative treatment interventions in 125 pediatric patients at our institution were reviewed. Because corticosteroid requirements were reduced significantly, only 23 of 125 children evaluated were considered for treatment alternatives with only 10 receiving such therapy. This study emphasizes the importance of a thorough and comprehensive review of corticosteroid requirements and usage prior to initiating alternative approaches to treatment in moderate to severe asthmatics as well as in patients thought to be “steroid-dependent.”     

Proton magnetic resonance spectroscopic imaging for discrimination of absence and complex partial seizures

We performed proton magnetic resonance spectroscopic imaging of the temporal lobes between, during, and soon after nonconvulsive seizures in 20 patients with documented temporal lobe epilepsy, 5 patients with primary generalized epilepsy, and 2 patients with secondary generalized epilepsy. Our objective was to determine whether there were metabolic changes observable by magnetic resonance spectroscopic imaging during seizures and whether these changes were specific for focal or generalized nonconvulsive seizures. We found a significant increase in lactate to creatine plus phosphocreatine (lactate/creatine) values, reflecting an imbalance in energy supply and demand or an adaptation in response to ictal neuronal discharges, during and soon after complex partial seizures, but not during or soon after absence seizures associated with generalized epilepsy. In patients with temporal lobe epilepsy, the N-acetylaspartate resonance relative to creatine plus phosphocreatine was low in one or both temporal lobes, indicating neuronal loss or damage. This was not observed in patients with primary generalized epilepsy. The regions with abnormal lactate/creatine and N-acetylaspartate/creatine values corresponded to the epileptogenic focus as defined by clinical-electroencephalographic investigation. There was no change in the N-acetylaspartate/creatine values in the temporal lobes between the interictal, ictal, or postictal states. We conclude that (1) partial seizures are associated with abnormally high lactate levels, but absence seizures are not, and (2) no short-term changes of N-acetylaspartate occur during or soon after complex partial seizures or absence seizures. These findings may be related to the lack of postictal confusion in patients with absence seizures, as well as with the more benign course of primary generalized epilepsy with nonconvulsive attacks.     

A comparative clinical study of the safety and efficacy of three toothbrushes.

This single (examiner) blind, randomized, 4-week study compared the safety and efficacy of a new electric toothbrush (experimental) regarding plaque removal and reducing gingivitis with two other brushes, an electric brush (control electric) and a manual toothbrush (control hand). Ninety-six subjects with 1) a minimum of 15 suitable teeth in acceptable occlusion; 2) a minimum gingivitis score of 0.9; and 3) a minimum plaque score of 1.8 were entered into the study. The subjects were randomly assigned to one of 3 groups: a control hand group (31 subjects), an experimental group (32 subjects), and a control electric group (33 subjects). Device use instructions were given according to the manufacturer's recommendations. Two examiners separately determined either gingival scores or plaque scores at baseline and 4 weeks. In regard to gingivitis, use of all 3 brushes for the study period showed statistically significant improvements in gingivitis scores (P values less than 0.01) within each of the 3 groups. Between group analyses of covariance showed that of the 3 groups, the control hand group improvement was better than both the experimental and the control electric groups (P less than 0.05). When interproximal gingivitis scores were analyzed separately, similar improvements were noted. Regarding effectiveness of plaque removal during a single brushing event at the initial and final visits, each of the 3 brushes was effective in reducing plaque for every tooth surface scored (P values less than 0.01). However, between group analyses of covariances showed that the experimental group was better than the other two (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac Surgery in Nonagenarians

A bstract Objectives and Background : The purpose of this study was to document our initial experience with patients 90 years of age and older and to determine whether cardiac surgery is justified in this age group. Cardiac surgery in octogenarians has proven to be a successful and worthwhile procedure. A small group of nonagenarians with severe coronary artery disease (CAD) and aortic valve disease refractory to medical therapy have been considered for surgery. Methods : Fourteen patients aged 90 or more underwent cardiac surgery for symptomatic CAD or aortic valvular disease refractory to medical therapy. Eight patients underwent isolated coronary artery bypass grafting (CABG) and six patients underwent aortic valve replacement (AVR). All patients were in NYHA Class IV preoperatively. Results : Hospital mortality occurred in one patient (7%). Hospital morbidity occurred in 10 patients (71%) and included 7 cardiac, 5 neurological, 1 gastrointestinal, 1 infectious, and 1 pulmonary event. All survivors left the hospital symptomatically improved. The mean length of stay was 26 days. Four CABG patients went on to die at a mean of 2 years and 2 months, and 3 remain alive at a mean of 2 years and 4 months. Three AVR patients expired at a mean of 3 years and 4 months, and 3 remain alive at 4 years and 1 month. Conclusions : Cardiac surgery in carefully selected nonagenarians is justified and can be performed with acceptable results.     

Autologous blood transfusion for pediatric bone marrow donors.

Nine normal bone marrow donors aged 7-166 months (median 69 months) received autologous red cells which had been removed from their marrow harvest after collection. The median volume of marrow removed from the donors was 18.6 ml/kg which was equivalent to a median blood volume loss of 23.3%. Three infant donors were transfused with autologous red blood cells intraoperatively. These cells had been salvaged from the initial marrow aliquot and were transfused while bone marrow harvesting continued. No donors required homologous blood transfusion. This technique is useful for marrow donors in the pediatric age group when preharvest autologous blood collection is not feasible or available.     

Amyotrophic lateral sclerosis patient antibodies label Ca2+ channel α1 subunit

Sporadic amyotrophic lateral sclerosis is an idiopathic human degenerative disease of spinal cord and brain motor neurons. Prior studies demonstrated that most patients with amyotrophic lateral sclerosis posses immunoglobulins that bind to purified L-type voltage-gated calcium channels, that titers of anti–voltage-gated calcium channel antibodies correlate with disease progression rates, and that amyotrophic lateral sclerosis patient-derived antibodies (ALS IgG) produce electrophysiological changes in the function of voltage-gated calcium channels. Using Western transfer immunoblots and enzyme-linked immunosorbent assays, the calcium ionophore–forming α₁ subunig of the voltage-gated calcium channel is now identified as the major voltage-gated calcium channel antigen to which ALS IgG binds. Additionally, the binding of an L-type voltage-gated calcium channel α₁ subunit–directed monoclonal antibody, which itself mimics the effects of ALS IgG on skeletal muscle voltage-gated calcium channel currents, is selectively prevented by preaddition of ALS IgG. Voltage-gated calcium channel–binding IgG from patients with Lambert-Eaton myasthenic syndrome appears to be differentiated from ALS IgG by the reactivity of the former to both α₁ and β subunits of the calcium channel. These assays provide further evidence linking amyotrophic lateral sclerosis to an autoimmune process, and suggest one means to differentiate immunoglobulins from patients with amyotrophic lateral sclerosis from those of patients with another autoimmune disease expressing calcium channel antibodies.