Advancing the standards of clinical research: the urgent need for new methods and better data

Some of the weaknesses of the randomized controlled trial (RCT) are pointed out, among them unavoidable biases, the possibility of coming to erroneous conclusions by the 'luck of the draw' and the fact that most such experiments lack a doctor/patient relationship and are of little assistance in clinical decision making. An exaggerated propensity on the part of the medical profession to regard the RCT as the only 'scientific' method for research into therapeutics is noted. The potential advantages of post-marketing surveillance of new interventions in a physician-centred manner are outlined. Such a data base could ultimately be expanded into a data base that records all activity in a given practice. The PACE strategy, employed by haematologists in the north of England, and the sentinel practice primary care research networks used by family doctors contain elements of the system proposed here. However, each possesses disadvantages that limit its applicability to special cases. Random choice of practices for any particular observational study of a new intervention could lend it some of the features of an experiment.

An instance of sleep paralysis in Moby-Dick

It is suggested that picturesque medical conditions can, at times, be encountered in literary works composed prior to their clinical delineation. This is true of sleep paralysis, of which the first scientific description was given by Silas Weir Mitchell in 1876. A quarter of a century earlier, Herman Melville, in Moby-Dick, gave a precise account of a case, including the predisposing factors and sexual connotations, all in accord with modern theory. The details of Ishmael's attack of sleep paralysis, the stresses leading up to it, and the associations causing him to recall the experience are given here.

Medicine and evolution: time for a new paradigm?

The theory of Evolution is being invoked frequently in medicine to account for counter-intuitive findings such as programmed cell death in congestive heart failure and the fact that fever can prove both blessing or curse, depending on the circumstances. These and other examples of what might be called maladaptive adaptations are discussed, and it is suggested that human development may have reached a stage where the roles of mutation and selection are drastically changed. By creating an environment both mutagenic and protective, we have altered the balance between the two great driving forces of evolution, increasing the frequency of mutations and reducing the need for adaptation. As a result, new diseases have arisen and the whole evolutionary process seems to have lost some of its benevolence, no longer insuring the survival of the fittest. We must entertain the possibility that Darwin's theory cannot explain the last few millennia of human evolution and is now useful chiefly as an approximation applicable to very long periods of time.

National Delphi study to determine competencies for nursing leadership in public health

PURPOSE

To identify competencies needed by nurse leaders in public health programs.

DESIGN

Five-round national Delphi.

SAMPLE

Convenience sample of members of major public health nursing associations and nurse and non-nurse public health leaders in the USA.

METHODS

Mailed survey in 1994-1995 using a modified snowball technique based on a modification of the Pew Foundation health professions' competencies for Round 1. Four additional rounds produced consensus.

FINDINGS

Initially, 62 competencies were identified. Factor analysis resulted in four factors: political competencies, business acumen, program leadership, and management capabilities; 57 competencies were clustered in the four groupings and accounted for 91.4% of the variance.

CONCLUSIONS

Graduate schools in nursing and public health must prepare students with broad-based competencies from a variety of disciplines. Findings of this national survey provide a database for curriculum development and evaluation of programs to prepare nurse leaders for roles in public health-based delivery systems.

Stability of nucleoside triphosphate levels in the red cells of the snake

Nucleated red cells in the nonpregnant garter snake (Thamnophis elegans) contain relatively high concentrations of nucleoside triphosphate (NTP), largely in the form of ATP, which is found at concentrations of approximately 10 mmol l-1 relative to cell volume and 15 mmol l-1 relative to cell water. During pregnancy, levels of NTP in adult red cells rise by approximately 50 % concomitant with an increase in blood progesterone level. The stability of the NTP pool within these red cells was assessed by maintaining cells in vitro at 20 °C, without exogenous nutrients, and in the presence and absence of the metabolic inhibitors iodoacetate and/or cyanide. After 96 h, NTP levels in adult red cells not exposed to the inhibitors had decreased by only approximately 10 %, while in the presence of both inhibitors NTP levels had fallen by less than 50 %. Red cell NTP levels were not affected by acute exposure to high concentrations of progesterone either in vivo or in vitro. NTP levels were much more labile when the cells were maintained in vitro at either low or high pH. Maintenance of red cells at pH 6.0 for 24 h resulted in a decrease in NTP levels of approximately 50 % and at pH 10.0 the levels fell by approximately 80 %, while buffers containing only ATP caused no detectable degradation. Incubation at low or high pH promoted some cell swelling; however, the magnitude of the decreases in intracellular NTP concentration prompted by these pH levels could not be mimicked by incubation of red cells in hypotonic buffer. Total nonspecific ATPase activity at pH 6.0 was approximately 55 % greater than that at pH 7.4, while at pH 10.0 it was approximately 6 % of that at pH 7.4. The pH-dependent decrease in intracellular NTP levels cannot, therefore, be due to stimulation of ATPase activity, at least not at high pH. Overall, the data are consistent with the hypothesis that an appreciable portion of the NTP within these cells is compartmentalized in a stable, but pH-sensitive, pool sequestered from intracellular ATP-hydrolyzing processes.

55-base pair deletion in certain patients with Gaucher disease complicates screening for common Gaucher alleles

Mutations in the glucocerebrosidase gene which result in Gaucher disease can originate from the highly homologous glucocerebrosidase pseudogene. A 55-bp deletion in exon 9, which corresponds to a 55-bp segment absent from the pseudogene, has been identified in patients with Gaucher disease. We have developed a simple polymerase chain reaction (PCR)-based method to detect this 55-bp deletion, and have found this mutation in 3 of 75 DNA samples (4%) collected from patients with Gaucher disease. Commonly used PCR-based screening methods for specific Gaucher mutations frequently make use of primers either within or surrounding the 55-bp gap to selectively distinguish the glucocerebrosidase gene from the pseudogene. However, if the 55-bp deletion in exon 9 occurs, primers will either fail to produce an amplification product or will produce a shortened product which will be falsely attributed to the pseudogene. This could lead to inaccurate genotyping and genetic counseling for some Gaucher patients and their families. We therefore recommended that laboratories using PCR-based screening techniques involving primers in this region initially determine whether this 55-bp sequence is present.

Characterization of antigenic peptides presented by HLA-B44 molecules on tumor cells expressing the gene MAGE-3

The amino acid sequence of the protein encoded by the gene MAGE-3 was screened for peptides containing the binding motif for HLA-B44. Nine peptides were synthesized, and their binding affinity for HLA-B*4402 and -B*4403 was analyzed in an HLA class I alpha-chain refolding assay. Four peptides with binding affinity for HLA-B*4403 were chosen for in vitro cytotoxic T-lymphocyte induction assays using as antigen-presenting cells peptide-pulsed, autologous activated B lymphoblasts from a healthy, B*4403+ donor. Peptide-specific effectors could be raised only against one peptide, M3-167. Cytotoxic T lymphocytes specific for this peptide were also able to recognize melanoma cell lines expressing HLA-B44 and the gene MAGE-3, strongly suggesting that M3-167 is a naturally processed MAGE-3-encoded epitope presented by HLA-B44. M3-167 is a I amino acid N-terminal extension of M3-168, a naturally processed epitope MAGE-3-encoded epitope presented by HLA-A1 that has been previously described. TAP binding studies of these 2 peptides revealed that the TAP affinity of M3-167 is about 9-fold higher than that of M3-168. M3-167 or a longer precursor could be transported into the endoplasmatic reticulum, where it could be trimmed for presentation by HLA-A1 or -B44 molecules. Taken together, our data suggest that M3-167 could be an immunodominant peptide encoded by the gene MAGE-3.

A peptide encoded by the human MAGE3 gene and presented by HLA-B44 induces cytolytic T lymphocytes that recognize tumor cells expressing MAGE3

The human MAGE3 gene is expressed in a significant proportion of tumors of various histological types, but is silent in normal adult tissues other than testis and placenta. Antigens encoded by MAGE3 may therefore be useful targets for specific antitumor immunization. Two antigenic peptides encoded by the MAGE3 gene have been reported previously. One is presented to cytolytic T lymphocytes (CTL) by HLA-A1, the other by HLA-A2 molecules. Here we show that MAGE3 also codes for a peptide that is presented to CTL by HLA-B44. MAGE3 peptides containing the HLA-B44 peptide binding motif were synthesized. Peptide MEVDPIGHLY, which showed the strongest binding to HLA-B44, was used to stimulate blood T lymphocytes from normal HLA-B44 donors. CTL clones were obtained that recognized not only HLA-B44 cells sensitized with the peptide, but also HLA-B44 tumor cell lines expressing MAGE3. The proportion of metastatic melanomas expressing the MAGE3/HLA-B44 antigen should amount to approximately 17% in the Caucasian population, since 24% of individuals carry the HLA-B44 allele and 76% of these tumors express MAGE3.

The ethics of prevention: old twists and new

The medical profession's tendency to equate 'the greatest good for the greatest number' with proactive care is here challenged; and the idea that we can always get more for our money with an ounce of prevention than with a pound of cure is scrutinized from an ethical point of view. It is suggested that preventive measures are often exempted from such scrutiny because they make medicine appear selfless and are aimed at the postponement of death-always an urgent matter. Indeed, our screening efforts can assume the proportions of a crusade against life's natural termination and we must make sure that they do not emanate from the needs of medical science for publicity and funding. The costs of what has been called 'healthism', something that has almost become a new morality, are frequently underestimated and its side effects overlooked. There are conditions for which effective palliation, sometimes enormously expensive, is available. The automatic assumption that money spent on such palliation could be better used for, say, immunization, is not warranted.

Effects of hypoxia and hyperoxia on oxygen-transfer properties of the blood of a viviparous snake

Red cell oxygen affinity, red cell nucleoside triphosphate (NTP) levels and blood oxygen-carrying capacity were determined for male, nonpregnant and pregnant female, and fetal garter snakes Thamnophis elegans exposed to hypoxia (5 % oxygen) and hyperoxia (100 % oxygen). Male and nonpregnant female snakes were maintained under these conditions for up to 3 weeks and exhibited an apparent maximal change in oxygen affinity after 14 days of hypoxia and hyperoxia. Red cell NTP levels decreased and oxygen affinity increased with exposure to hypoxia, while exposure to hyperoxia promoted an increase in red cell NTP concentrations and a decrease in red cell oxygen affinity in the males. Hyperoxia-exposed nonpregnant females did not show a significant change in oxygen affinity. After 14 days of hypoxia, the pregnant females showed an increase in red cell oxygen affinity which was associated with a decrease in red cell NTP concentration and in the molar ratio of NTP/hemoglobin relative to normoxic controls. Fourteen days of hyperoxia did not result in a change in oxygen affinity of red cells from the pregnant female, but did promote a slight increase red cell NTP concentrations. The blood parameters of fetuses from females exposed to hypoxia or hyperoxia did not differ from those of normoxic control fetuses. The fetuses of females exposed to hypoxia suffered greater mortality, appeared less developed and had a lower average wet mass than the fetuses of normoxic- and hyperoxic-exposed females. Neither hypoxia nor hyperoxia altered the oxygen-carrying capacity of the blood in any group of snake.

Hyperlucent lung secondary to homocystinuria

At 23 months of age, one of a pair of monozygotic twins with radiographic unilateral hyperlucent lung was evaluated by radionuclide ventilation/perfusion pulmonary studies, which revealed a ventilation/perfusion mismatch of an entire lung. This twin died, and autopsy revealed pulmonary arterial thrombosis and histological changes compatible with homocystinuria, which was subsequently shown to be present in the surviving twin as well. A ventilation/perfusion lung scan of the surviving twin revealed multiple ventilation/perfusion mismatched defects, suggestive of pulmonary embolism. The presenting manifestation of homocystinuria in these patients was the pulmonary thrombotic disease. Neither twin had any other stigmata of homocystinuria at the time of initial presentation.

Prevalence of Neospora caninum and Toxoplasma gondii antibodies in coyotes (Canis latrans) and experimental infections of coyotes with Neospora caninum

Antibodies to Neospora caninum were detected in 5 (10%) of 52 coyotes from Texas. Antibodies to Toxoplasma gondii were detected in 32 (62%) of 52 samples from these same coyotes. Four (80%) of the 5 coyotes that were seropositive for N. caninum also had antibodies to T. gondii. Nineteen (37%) of the coyotes did not have antibodies to either parasite. Three coyote pups were inoculated with the brains from mice infected with 3 strains of N. caninum originally isolated from dogs. None of the pups developed neosporosis or excreted N. caninum oocysts in their feces. The pups developed anti-N. caninum antibody titers of > or = 1:800 but did not develop antibodies to T. gondii. Results of this study indicate that antibodies to T. gondii are more common than antibodies to N. caninum in coyotes. Additionally, young coyotes appear to be resistant to experimental N. caninum infection.

[Retroperitoneoscopic lumbar symathectomy]

During the period between August 1995 and February 1996 at the Second Surgical Clinic of the Faculty Hospital in Olomouc 12 retroperitonescopic lumbar sympathectomies were performed on account of different indications. The authors present an elaborate technique of access into the retroperitoneum and their own technique of lumboscopic sympathectomy. The success of the method was evaluated clinically and by histological evidence of sympathetic ganglia in the collected material. Retroperitoneoscopic lumbar sympathectomy is considered a gentle and safe method which can be used also in other patients where the risk of open surgery would be excessive.

Genotype D399N/R463C in a patient with type 3 Gaucher disease previously assigned genotype N370S/R463C

A patient with type 3 Gaucher disease is described with a novel genotype, D399N/R463C, established by DNA sequencing. This patient was previously reported as having genotype N370S/R463C. This communication now establishes that no patients reported with mutation N370S have the neuronopathic forms of Gaucher disease and has important implications for genetic counseling.

Therapeutic nihilism?

The view that the era of modern medicine began with the introduction of the sulfonamides is supported by a standard textbook of pharmacology that refers to the years 1908-35 as being characterized by "therapeutic nihilism". However, a survey of several sources listing some of the treatments then available yields 15 infectious, 7 deficiency and 3 endocrine disorders amenable to cure. In addition, palliation that even today would be considered rational could be given for congestive heart failure, angina pectoris, asthma, epilepsy, migraine, and Parkinson's disease, to mention only a few. A total of 38 surgical, pharmacological, nutritional and physical remedies were identified, many of them still in use. These findings represent a minimum estimate as the review was not exhaustive, being aimed chiefly at recapturing the therapeutic atmosphere prevailing 75 years ago. Nothing in the textbooks of medicine, pharmacology and treatment suggests that physicians of the 1920's lacked either the means or the enthusiasm for treating their patients.