Tetanus in a 67-year-old man

A fatal case of generalized tetanus in a 67-year-old man is presented. The incubation period following finger damage was short, and the diagnosis was confirmed by the isolation of Clostridium tetani. Subsequently, a partial surgical amputation of the infected finger during the clinically active stage of the disease did not remove all the infecting organisms. Although convincing evidence of any previous active immunization was lacking, no form of tetanus antitoxin was given at the time of injury. This case illustrates the potential dangers of unfamiliarity with tetanus owing to its low incidence in developed countries.     

Anicteric cholestasis in a 75-year-old man

This presentation challenges the purveyors of the importance of "positive thinking" in the cure of cancer. Psychological support should allow the patient to come to terms with his or her situation in a way that works for that individual within a caring and realistic environment. In no way should psychological support add an extra burden to an already devastated patient. By forcing "positive mental attitude", health-care professionals are not allowing patients to face reality. Promoters of the "cure" that comes with positive thinking are quoted, as well as authors who question the promoters' intent and outcome. It is felt that "positive thinking" may be appropriate as one of many successful coping strategies. To attribute more to it or, worse, to insist that patients believe in its power to cure may be courting emotional disaster.     

Macrophage activation in a 74-year-old man

The Artemia hemoglobin is a dimer comprising two nine-domain covalent polymers in quaternary association. Each polymer is encoded by a gene representing nine successive globin domains which have different sequences and are presumed to have been copied originally from a single-domain gene. Two different polymers exist as the result of a complete duplication of the nine-domain gene, allowing the formation of either homodimers or the heterodimer. The total population size of 18 domains comprising nine corresponding pairs, coupled with the probability that they reflect several hundred million years of evolution in the same lineage, provides a unique model in which the process of gene multiplication can be analyzed. The outcome has important implications for the reliability of local molecular clocks. The two polymers differ from each other at 11.7% of amino acid sites; however when corresponding individual domains are compared between polymers, amino acid substitution fluctuates by a factor of 2.7-fold from lowest to highest. This variation is not obvious at the DNA level: Domain pair identity values fluctuate by 1. 3-fold. Identity values are, however, uncorrected for multiple substitutions, and both silent and nonsilent changes are pooled. Therefore, to determine the variability in relative substitution rates at the DNA level, we have used the method of Li (1993, J Mol Evol 36:96-99) to determine estimates of nonsynonymous (KA) and synonymous (KS) substitutions per site for the nine pairs of domains. As expected, the overall level of silent substitutions (KS of 56. 9%) far exceeded nonsilent substitutions (KA of 6.7%); however, for corresponding domain pairs, KA fluctuates by 2.3-fold and KS by 1. 7-fold. The large discrepancies reflected in the expressed protein have accrued within a single lineage and the implication is that divergence dates of different genera based on amino acid sequences, even with well-studied proteins of reasonable size, can be wrong by a factor well in excess of 2.     

Vitelliform dystrophy in a 64-year-old man

A device suitable for the long-time measurement of relative skin humidity is described. This is a simple circuit with a resistance bridge for lithium chloride sensors connected to a digitally steered logic circuit, which causes dried air to stream intermittently through a measuring chamber placed on the skin in such a way that the relative humidity over the skin is maintained at a constant level. The number of switching time periods is proportional to the relative humidity (secretion performance) of the skin and can be counted, recorded, or directly fed into a digital calculator. The apparatus, including a two-channel version with skin temperature recording, has proved useful in sleep investigations under extreme climatic conditions.