Biomedical subjects
H Hillman
Publications and source records attributed to H Hillman.
Reduction in mortality from upper gastrointestinal haemorrhage.
A study of 2377 cases of haemorrhage from the upper gastrointestinal tract shows a significant fall in mortality rate--from 15.5% in the period of retrospective study from 1961 to 1970 to 7% in the prospective study from 1972 to 1982. The fall in mortality rate from non-variceal bleeding was from 12.8% to 5%. In the second five years of the prospective study, the total mortality rate was 5.8%, with 4.5% for non-variceal haemorrhage. This improvement occurred despite a significant rise in the proportion of patients of 60 years of age and over, and was particularly evident in patients with bleeding chronic gastric ulcers. There was also a significant reduction in mortality in the 60 years and over age group in the latter five years of the prospective study. The data suggest that there were three aspects of management which were important in the reduction of mortality. These were early fibreoptic endoscopic diagnosis, improved resuscitation and postoperative care, and early control of bleeding from oesophageal varices by balloon tamponade and surgery in selected cases. These complicated procedural aspects of management are best applied in a special unit for the treatment of patients with haemorrhage from the upper gastrointestinal tract. It is concluded that there has been significant progress in the treatment of this problem during the last decade.
Dying and death, with special reference to brain death. A bibliography.
A bibliography of dying and death has been made, with special reference to the brain. It does not claim to be comprehensive. Short references have been omitted unless they contained new information not published elsewhere. When books or papers have been written in other languages, their titles have been translated, and their original languages indicated. It has not always been possible to find the complete page references to these.
Preparation of an insoluble fraction of ox brain and its affinity for Na+ and K+.
A water insoluble fraction was prepared from ox cerebrum by homogenization in water, dialysis against water, washing with water and drying in air at 293 degrees K. The fraction represented 15.5 +/- 3% (n = 8) of the weight of the fresh brain; it contained means of 81% (n = 6) of the lipid, found in freshly dried ox brain samples, and 46% (n = 5) (biuret method) or 51% (n = 3) (6) of the protein, respectively. The Na+ and K+ concentrations were measured by atomic emission flame photometry, firstly, in prepared media, and then after 4 ml of the same media had been mixed with 1 g of the insoluble fraction at 310 degrees K for 20 min; the concentration in the fraction was calculated from that found in the medium. The concentration in the medium (mM) after incubation was compared with that calculated to be in the fraction, (mumol/g). When the insoluble fraction was mixed with Krebs Ringer saline containing bicarbonate and glucose, modified so that the ratios of NaCl and KCl varied-(although together they always added up to 150 mM)-there was a mean of 2.6 times as much Na+ or K+ in the fraction (mumol/g) as in the media (mM) when the latter contained up to 80 mM Na+ or K+. When the concentration of the cations in the media exceeded this value, the concentration of Na+ in the fraction rose considerably, while the concentration of K+ fell to zero. When only Ca2+ or only Mg2+ was omitted from the Krebs-Ringer bicarbonate glucose saline, the fraction did not take up Na+ or K+ from the medium at any concentration. On electron microscopy the fraction was granular and amorphous and contained myelin figures. The fraction did not take up any significant volume of oxygen measured manometrically either in the modified Krebs-Ringer solutions or in a mitochondrial substrate.
Vegetarianism--an alternative diet or a crazy fad?
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Artefacts in electron microscopy and the consequences for biological and medical research.
It has been previously shown that the endoplasmic reticulum, the Golgi apparatus, the lysosomes, the nuclear pores, and the cristae of the mitochondria could not exist in living cells. Therefore, study of them in all life sciences, or any apparent correlation between their 'structure' and 'function' should be abandoned. The consequences to biological and medical research of such conclusions are considered. Semantic and logical analyses of experiments should always be done, and all the assumptions inherent in them should be identified and tested. Research should be more directed to studies on whole living animals, rather than to metal deposits, precipitation patterns, homogenates, or tissue fixed or subjected to other powerful physical and chemical agents known to change them drastically.
Staining of isolated rabbit neurons and neuroglial clumps.
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The World Medical Association.
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How productive is medical research?
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Area changes in slices of rat brain during preparation for histology or electron microscopy.
Cerebral slices cut from rat brain, either 2-3 mm or 0.27 mm thick, were used to study the effect of embedding and freezing. Paraffin wax sections 6 micrometer thick were mounted and stained with haematoxylin and eosin or Marsland et al.'s (1954) silver stain, and their areas were examined at each step. Embedding in paraffin wax of slices 2-3 mm thick, or in Epon of slices 0.27 mm thick, caused a diminution of their areas by 20-30%. Staining of paraffin wax sections did not alter their areas. Glycerol alone at 15% concentration had no effect on the areas, but at 30% concentration they were diminished by approximately 20%. Diminution of the areas of glycerol treated slices 0.27 mm thick also occurred when they were transferred to liquid N2 or to isopentane, but the areas increased after glycerol was replaced by Freon 12. It was concluded that embedding or freezing cerebral slices caused changes in their areas, but that staining of sections after they had been embedded, sectioned and mounted did not.
The unit membrane, the endoplasmic reticulum, and the nuclear pores are artefacts.
It is shown on the basis of solid geometry that the trilaminar appearance of membranes described by Robertson must be an artefact, although the membranes themselves are not. However, considerations of solid geometry as well as observations on living cells indicate that the endoplasmic reticulum and nuclear pores are artefacts resulting from preparation for electron microscopy. Suggestions for their genesis are proposed.
The effect of six fixatives on the areas of rabbit neurons and rabbit and rat cerebral slices.
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Towards a classification of evidence in biological and medical research in respect of its validity.
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The uptake of low concentrations of lithium ions into rat cerebral cortex slices and its dependence on cations.
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Proceedings: The fine structure of the living cell-a reappraisal. Television film.
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The histological localization of DNA in rabbit medullary neurons.
The nuclei of unfixed isolated rabbit neurons cleared on incubation with DNAse (10 mg/ml), but not RNAse (10 mg/ml). The nuclei stained for DNA with eight chromosomal or nuclear stains more intensely than the cytoplasm, and less intensely after treatment with DNAse (10 mg/ml). On the other hand, when the whole tissue was embedded and sectioned, DNA did not appear to be stained in the nucleus; the nucleolus and the cytoplasm were more heavily stained than the nucleoplasm. Possible explanations for this apparent anomaly are considered. It was concluded that DNA diffused out of the nucleus during embedding and sectioning, and that the colouration of the nucleolus and cytoplasm with the eight staining systems used was due to other nucleotides present.