In what sense is contemporary medicine dualistic?

Medicine's inability to humanely respond to the concerns of its patients has often been attributed to its Cartesian dualism of mind and body. More recently, this inability has been ascribed to medicine's penchant for isolating biological disease as its sole proper concern to the exclusion of experienced illness. This dualism of disease and illness is claimed to be an outgrowth of the Cartesian dualism but the differences and similiarities between these two forms of dualism is not clear. This paper seeks to clarify their relationship through an examination of their historical origins.Disease is currently identified and characterized by a process of clinico-pathological correlation. By this means clinical impressions are corrected in light of autopsy findings. Our current mode of clinico-pathological correlation originated in Paris in the early nineteenth century with the work of Xavier Bichat and others. The theory of knowledge implicit within this clinico-pathological approach to the body is described and compared to that of Descartes. Though medicine does pursue certain Cartesian goals for knowledge, such as knowledge of the patient that does not rely upon his candor, it ultimately espouses neither a Cartesian theory of knowledge nor a Cartesian theory of the body. With pathological inquiry modeled after the autopsy as the final word in the identification and characterization of disease, the patient's capacity for self-knowledge and interpretation — not an entity called mind — is isolated away from his body. This approach to the body means that objective evidence of disease is valued to the exclusion of subjective evidence.If the shortcomings of modern biomedicine are to be effectively addressed, not only must the interdependence of disease and illness be acknowledged. The very canons of medical evidence must be revised. Subjective evidence must be rehabilitated and rejuvenated with better methods of subjective clinical investigation. Host factors relevant to the healing and knowing of sickness must be elucidated so that medicine may rediscover the sentience of its patients. Department of Psychiatry and Behavioral Sciences University of Washington Seattle, WA 98195, U.S.A.     

The structure of cruciforms in supercoiled DNA: probing the single-stranded character of nucleotide bases with bisulphite.

The single-stranded character of cytosine bases in three cruciform structures has been assessed by an examination of reactivity towards sodium bisulphite. Unpaired cytosine residues undergo deamination at C4 to give deoxyuracil, and propagation in an ung Escherichia coli host results in C-G----T-A transition mutations, detectable by restriction cleavage or sequence analysis. Very high frequencies of such mutations have been found at cruciform loops, confirming their unpaired character, with almost zero background mutation frequencies elsewhere. A low level of modification was observed at the four-way junction of a cruciform. The results indicate that the optimal cruciform loop size is four bases, with loose 'breathing' at the first base pair at the top of the cruciform stem at 37 degrees C, and little or no opening of base pairs at the four-way junction.     

Stability of tissue culture medium pH as a function of autoclaving,time, and cultured plant material

Autoclaving is a standard procedure for sterilizing nutrient media for plant tissue cultures. Most tissue cultures are grown at pH 5.2 to 5.8 with pH adjustments being made prior to autoclaving. This paper reports that there are significant differences between initial pH levels and pH levels following autoclaving, particularly in the pH range of 5.7 to 8.5. This effect is noted with and without agar. In addition, we report that with time the pH of the medium drifts into the acid range. When Cucumis callus was added to the medium, the pH was changed significantly within 48 hours. The amount and direction (increase or decrease of pH) was significantly correlated with the original pH. This suggests that researchers should be wary of the true pH situation in their medium. In addition, in publications authors should specify whether their medium pH value was determined before or after autoclaving.     

Comparison of the Limulus amoebocyte lysate test with plate counts and chemical analyses for assessment of the quality of lean fish.

The quality of lean fish was assessed simply and rapidly with Limulus amoebocyte lysate. The endotoxin levels agreed with aerobic plate counts and chemical indices of spoilage. Correlation between level of endotoxin and level of total volatile bases was found to be highly significant (r = 0.8579; P less than 0.001).     

Airway anesthesia effects on hypercapnic breathing pattern in humans

Minute ventilation (VE) and breathing pattern during an abrupt increase in fractional CO2 were compared in 10 normal subjects before and after airway anesthesia. Subjects breathed 7% CO2-93% O2 for 5 min before and after inhaling aerosolized lidocaine. As a result of airway anesthesia, VE and tidal volume (VT) were greater during hypercapnia, but there was no effect on inspiratory time (TI). Therefore, airway anesthesia produced an increase in mean inspiratory flow (VT/TI) during hypercapnia. The increase in VT/TI was compatible with an increase in neuromuscular output. There was no effect of airway anesthesia on the inspiratory timing ratio or the shape and position of the curve relating VT and TI. We also compared airway resistance (Raw), thoracic gas volume, forced vital capacity, forced expired volume at 1s, and maximum midexpiratory flow rate before and after airway anesthesia. A small (0.18 cmH2O X l-1 X s) decrease in Raw occurred after airway anesthesia that did not correlate with the effect of airway anesthesia on VT/TI. We conclude that airway receptors accessible to airway anesthesia play a role in hypercapnic VE.     

Differential regulation of duplicate alcohol dehydrogenase genes in Drosophila mojavensis

These studies report the existence of multiple forms of alcohol dehydrogenase in extracts of Drosophila mojavensis. The existence of these forms can be best explained by the hypothesis of a duplication for the Adh locus in D. mojavensis. Electrophoretic variants at each locus have been identified and crosses between individuals carrying alternative alleles at each locus result in F1 progeny with six bands of ADH. This pattern is consistent with these individuals being heterozygous at two loci. The loci have been named Adh-1 and Adh-2. Examination of the isozyme content during development shows that the two Adh genes are not coordinately controlled but have separate developmental programs. In embryos and first and second instar larvae only Adh-1 is expressed. At about the time of the second molt Adh-2 expression commences in some of the same cells that previously expressed and continue to express Adh-1. This is evidenced by the existence of an interlocus heterodimer in third instar larvae. Both genes are expressed throughout pupation. Shortly after emergence Adh-1 expression declines. In mature males only ADH-2 is present. In mature females both Adh-1 and Adh-2 are expressed but not in the same cells since the interlocus heterodimer is absent. Examination of specific tissues reveals that most of the larval ADH is found in fat body cells and as in most tissues of third instar larvae both Adh-1 and Adh-2 are expressed. The single exception appears to be larval gut which contains ADH-1 but little if any ADH-2. In mature males and female flies all ADH containing tissues have only ADH-2. However, mature ovaries contain substantial quantities of ADH-1 which is apparently deposited into eggs. Given the extensive amount of available information on the Adh gene-enzyme system of D. melanogaster and the tools that can be applied to the analysis of homologous systems, the ADH duplication of D. mojavensis, and its regulation may be a useful one for studying differential gene regulation in specific cell types.     

Stimulation of cholesterol side-chain cleavage by a luteinizing-hormone-releasing hormone (luliberin) agonist (ICI 118630) in rat Leydig cells.

The action of a luliberin (luteinizing-hormone-releasing hormone) agonist (ICI 118630) and lutropin (luteinizing hormone) on the activity of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat Leydig cells has been investigated. This has been carried out by studying the metabolism of exogenous (22R)-22- and 25-hydroxycholesterol to testosterone. It was found that both hydroxycholesterols increased testosterone production to higher levels than achieved by lutropin alone. Addition of luliberin agonist but not lutropin was found to increase further the metabolism of the hydroxycholesterol to testosterone; this occurred in the presence of saturating and subsaturating levels of the hydroxycholesterols. This effect of luliberin agonist was potentiated in the presence of lutropin. The protein synthesis inhibitor, cycloheximide, inhibited the luliberin agonist-induced stimulation of the hydroxycholesterol metabolism. At low calcium levels (1.1 microM), testosterone production was increased by addition of (22R)-22-hydroxycholesterol but the luliberin agonist effect was negated. The calmodulin inhibitor trifluoperazine inhibited (22R)-22-hydroxycholesterol-stimulated steroidogenesis and negated the luliberin agonist effect. These results indicate that luliberin agonist specifically increases the synthesis of the cytochrome P-450 cholesterol side-chain cleavage enzyme in rat testis Leydig cells.     

Inactivation of Thirty Viruses by Gamma Radiation

Decimal reduction values (D value) for 30 viruses were determined. The weighted D values of the viruses suspended in Eagle's minimum essential medium ranged from 0.39 to 0.53 Mrads. It was necessary to increase the radiation dose by a factor of >3 to inactivate virus suspended in Eagle's minimum essential medium as compared to the same virus suspended in distilled water. The destruction rate curves were of a first-order reaction.     

Metabolic Regulation by Homoserine in Escherichia coli B/r

A mathematical analysis of branched pathway regulation has led to the prediction of a novel homoserine control in Escherichia coli B. Experimental support for such control is presented in this paper. Homoserine, the precursor of both threonine and methionine, inhibits nicotinamide adenine dinucleotide phosphate (NADP(+))-specific glutamate dehydrogenase (EC 1.4.1.4), the enzyme catalyzing the first reaction in ammonia assimilation. Physiological and biochemical evidence for this effect are offered. Homoserine depresses the growth rate of the organism, and glutamate, the product of the inhibited reaction, reverses this effect. The NADP(+)-specific glutamate dehydrogenase activity in cell-free extracts is inhibited by homoserine, and this inhibition parallels the restriction of growth rate. These effects are found in other enteric bacteria which share a similar overall pattern of control for the amino acids derived from aspartate. On the other hand, a sampling of more distantly related species which have different pathways and/or regulatory patterns provides no evidence for homoserine inhibition of the glutamate dehydrogenase reaction.