Programmed cell death and the gene behind spinal muscular atrophy

A gene involved in the development of spinal muscular atrophy (SMA) has been found on human chromosome 5 after a 4-year search. Named the neuronal apoptosis inhibitor protein (NAIP) gene, it is believed to inhibit the normal process of apoptosis--the disintegration of single cells that results from programmed cell death--in motor neurons. The researchers who found the NAIP gene also discovered that healthy people carry one complete copy of the gene along with many other partial copies. Many children with SMA have the partial copies but not the complete gene. This discovery facilitates the accurate genetic diagnosis of SMA. But gene therapy for SMA will not be possible until researchers find a suitable vector to stably introduce activated and intact copies of the gene into the motor neurons of children with SMA in time to stop motor neuron loss.

Immune response and protection against influenza A infection in mice immunised with subunit influenza A vaccine in combination with whole cell or acellular DTP vaccine

Following the demonstration of the strong adjuvant effect of whole-cell DTP vaccine (wDTP) on the immune responses to influenza subunit vaccine, studies were undertaken to identify the component of wDTP responsible for the adjuvant effect, and to determine if acellular DTP (aDTP) vaccine was as effective since it is less reactogenic and likely to replace wDTP for primary or secondary immunisation. In addition, wDTP and aDTP were directly compared in a dose-response study. Experiments in mice indicated that the adjuvant effect of wDTP resided in the LPS component of B. pertussis, since purified LPS enhanced the IgG antibody response, the IgG subclass response and protection to the same level as wDTP. An adjuvant effect was detected using aDTP, but was statistically less pronounced than wDTP by a factor of some 100-fold. These results suggest that immunisation against influenza in infants and young children can be achieved combining small amounts of influenza antigen with wDTP or LPS, and to a lesser extent by combining vaccine with aDTP. However, these results were obtained in mice and should be confirmed in man since species vary considerably in response to adjuvant.

Advanced clinical roles: investigating dilemmas and changing practice through action research

A new career structure for clinical nurses was implemented in 1987 in Victoria with the intention of providing clinical advancement and material rewards for nurses in clinical settings. This paper explains how participatory action research was used to explore some of the issues inherent in the role of the associate charge nurse. The clinical/management tension and the role expectations formed within the taken-for-granted rituals and routines of the ward and the hospital managerial structure are examined.

Mouse models and breast cancer

With his colleagues at McMaster University in Hamilton, Ont., molecular biologist Dr. William J. Muller has developed strains of transgenic mice to study the roles of certain genes in the development of mammary epithelial cancer. Genes of particular interest include neu, which codes for a growth factor receptor, and c-src, one of the first oncogenes ever described. The outcome of this work is a better understanding of how breast cancer starts and of the prognosis for patients with certain forms of the disease. It is expected that murine models will also be used to test the efficacy of new therapies for breast cancer.

Overnight pulse oximetry in snoring and non-snoring children

The effect of snoring on overnight pulse oximetry recordings in the paediatric community was investigated. A random sample of 222 children up to 10 years of age from the town of Frome, Somerset, UK, had overnight pulse oximetry performed in the home environment. The oximetry recordings obtained from 58 snoring and 164 non-snoring subjects were compared. No clinically relevant difference in oxygen saturation level could be detected between these two groups of children. In conclusion, snoring in children up to 10 years of age is common, 11% often snore. It is not associated with hypoxia as measured by overnight pulse oximetry. This would suggest that surgical intervention for the symptom of snoring alone is not indicated.

Sex chromosome tetrasomy and pentasomy

Sex chromosome abnormalities occur in at least 1 in 400 births and include the well-described 47,XXX, 47,XXY, 47,XYY, and 45,X karyotypes. The addition of more than one extra X or Y chromosome occurs rarely, and little information is available in the medical literature. Individual case reports make up most of this body of knowledge, and all are based on subjects who identified themselves postnatally. Many were ascertained through screenings of institutions and hospitals; thus, there is no unbiased information on the natural history of poly X and Y karyotypes. A direct relationship between the number of additional sex chromosomes and the severity of the phenotype is generally assumed. The purpose of this article is to summarize what is known about these conditions and to present 10 additional cases. The karyotypes include, 48,XXXX, 49,XXXXX, 48,XXYY, 48,XXXY, 49,XXXXY, 49,XXXYY, 48,XYYY, 49,XYYYY, and 49,XXYYY.

Co-trimoxazole induced aseptic meningitis

A 15 year old boy presented with two episodes of aseptic meningitis-like reactions after ingestion of co-trimoxazole. The diagnosis of co-trimoxazole induced aseptic meningitis was made. This syndrome should be considered in the differential diagnosis of aseptic meningitis.

Requests approaching 50,000 annually for emergency drug release program

Health Canada's Emergency Drug Release Program, which allows physicians to acquire nonmarketed drugs to treat people with HIV infection, AIDS and other illnesses, handles about 44 000 requests annually. The executive director of the Drugs Directorate says the program's name is a misnomer, since few of the requests involve medical emergencies. Dr. Philip Berger, who uses the program for his AIDS patients, complains that the amount of paperwork required is oppressive. A government spokesperson says changes may be made to make the program less labour intensive.

Human antibody response to meningococcal transferrin binding proteins: evidence for vaccine potential

During iron-limited growth Neisseria meningitidis expresses two transferrin binding proteins, TBP1 and TBP2, with molecular masses of approximately 98 and 65-90 kDa depending on strain. Mixtures of TBP1 and TBP2 (TBP1 + 2) from three meningococcal strains were purified using affinity chromatography and used to determine anti-TBP antibodies in human sera by ELISA. Sera were obtained from healthy individuals, asymptomatic carriers of N. meningitidis and cases of meningococcal disease. Healthy individuals had little detectable antibody to TBPs but sera from carriers and cases exhibited a response demonstrating that TBPs are expressed in vivo during both carriage and disease. The ELISA absorbances produced by each of the individual sera to TBPs from the three meningococcal strains were compared and very high correlation coefficients were obtained, indicating that human anti-TBP antibodies, in contrast to mouse and rabbit antibodies, are cross-reactive between strains. Antibodies to separately purified TBP1 and TBP2 were also detected in both cases and carriers. The IgG and IgM response to TBP1 + 2 was greater in cases than carriers but the mean IgA response was the same. This demonstration of an antibody response that is cross-reactive between TBP types greatly strengthens the case for inclusion of TBPs in a meningococcal vaccine to protect against all serogroups and serotypes.

Harvesting blood proteins from grain

A multidisciplinary team of researchers at the University of Ottawa has expressed a human blood protein, granulocyte-macrophage colony stimulating factor, in tobacco seeds as part of a series of experiments whose ultimate goal is to express human blood proteins in cereal crops. Success in these experiments may lead to the development of a new, relatively inexpensive and ready supply of these proteins from a biologic source that is generally recognized as safe. The team is also studying the possibility of expressing in seeds proteins that may be used as vaccines against infectious diseases.

Psychosocial adaptation of 39 adolescents with sex chromosome abnormalities

OBJECTIVES

Children with sex chromosome abnormalities (SCA) are known to be at increased risk for neuromotor, language, learning, and behavioral problems, but little is known of psychosocial adaptation of SCA adolescents. This study was conducted to evaluate psychologic characteristics of unselected SCA adolescents, including socialization, educational progress, separation from family, and incidence and severity of psychiatric disturbance.

METHODS

Thirty-nine propositi identified through the screening of 40,000 consecutive Denver newborns, including boys with 47,XXY karyotypes and girls with 47,XXX, 45,X, and partial X monosomy, or SCA mosaic karyotypes, have been followed longitudinally into adolescence. Twenty-seven siblings served as controls. Between 12 and 19 years of age, all participated in blind psychiatric interviews and were administered standardized intelligence and achievement tests.

RESULTS

SCA propositi demonstrated a mean IQ score 21 points lower than that of control subjects. In addition, lower mean scores were seen on achievement test results as well as lower overall psychosocial adaptation scores and increased incidence of psychiatric disturbance. Depression was the most frequent psychiatric diagnosis. Propositi were more likely to receive special education assistance in high school and were less likely to graduate from high school than were controls. Of the three nonmosaic propositi groups, the 47,XXX girls demonstrated the poorest overall psychosocial adaptation and highest degree of psychiatric disturbance. Mosaic girls were indistinguishable from control subjects. Marked variability was found among all three nonmosaic groups, with some individuals in each group demonstrating relatively strong psychosocial adaptation.

CONCLUSIONS

The presence of nonmosaic sex chromosome abnormality increases the risk for impeded cognitive skills, learning abilities, and psychosocial adaptation in adolescence. The factors that allow for stronger adaptation in some of these adolescents include the presence of a stable and supportive family environment. The outlook for adaptation in unselected SCA adults remains uncertain.

After years of steady growth, winds of restraint blowing on prescription-drug industry

Tough fiscal times are forcing cutbaks in many areas of health care, and the prescription-drug industry is no exception. The Pharmaceutical Manufacturers Association of Canada says Canada's brand-name drug companies face two major hurdles: restricted market access, as drug formularies limit the number of new drugs, and restricted price increases, as allowed by the Patented Medicine Prices Review Board and provincial formularies. The Canadian Drug Manufacturers Association, which represents Canada's generic-drug industry, says its message to physicians is that generic products are important agents of cost control and that the health care community is more aware of this than it once was. "If you don't maximize your savings while you can," cautions the association's Brenda Drinkwalter, "you'll never be able to afford the high-priced drugs of tomorrow".

Transformative 'cultural shifts' in nursing: participatory action research and the 'project of possibility'

For some time scholars have called for changes in nursing in order to address the subjugated position of nurses within health care. This paper argues that through an engagement with participatory action research, nurses open up a possibility to bring about transformative shifts in nursing culture. The motivation for nurses to engage with this research process arises out of an acknowledgement that they can no longer live with the sense of pain and crisis endemic in much of their nursing practice, and a desire to take action to bring about transformative change within their local ward cultures. However, their participation in critical reflective and collaborative processes that underpin action research exposes an array of minor scattered nursing practices which frustrate possibilities for transformative change. Drawing on empirical accounts from research conducted by the author, the paper argues that once made explicit, these minor practices and the regimes of truth that nurture and sustain them, can be reconstructed and the possibility of transformative cultural shifts in nursing will then emerge.

DNA-based vaccines: new possibilities for disease prevention and treatment

Ottawa researcher Dr. Heather L. Davis has become a pioneer in the development of DNA-based vaccines. With her collaborators in France and Germany Davis found that introducing the DNA code for the envelope protein of the hepatitis B virus into the muscle tissue of mice prompted a strong and sustained immune response. She believes that DNA-based vaccines could prove to offer many advantages over conventional vaccines, not least of which are greater safety and effectiveness and reduced cost. She has also begun to explore the potential of DNA-based vaccines for use in the treatment of disease. In recent experiments Davis and colleagues in France have successfully used DNA vaccination to cure transgenic mice of a chronic hepatitis B carrier state.

Protection of mice from Bordetella pertussis respiratory infection using microencapsulated pertussis fimbriae

Conditions have been established which allow the efficient entrapment of Bordetella pertussis fimbriae in poly(lactide-co-glycolide) microspheres. Fimbriae released from the matrix were found to have retained some degree of conformational structure, as determined by assessing the capacity of fimbrial protein to bind to antibodies mapping to either conformational or denatured structures on the fimbriae, either encapsulated in microspheres with a mean diameter of 24 microns and an estimated in vitro protein release rate of approximately 42 days, or conventionally adjuvanted with alhydrogel, elicited vigorous immune responses in mice. The encapsulated fimbriae appear to elicit marginally lower serum antibody levels than those induced by equivalent amounts of alhydrogel-adjuvanted fimbriae. Mice immunised with both preparations were, however, protected against intranasal infection with live B. pertussis as evidenced by the significant reduction in levels of bacterial colonisation observed in the lungs and tracheas of immunised animals when compared to the immunologically naive controls.

Age, physical trauma and care

To cast light on the effects of aging on the metabolic responses to physical trauma an Ottawa researcher has studied strength and blood glucose metabolism in elderly people. He finds that because older people have less lean body mass, particularly muscle mass, than younger people, they are less able to tolerate trauma. They weaken faster and to a greater extent than younger patients who have experienced similar trauma, and they recover more slowly. At the same time, elderly people are less able to tolerate glucose, which is often given as part of their nutritional support. These findings have implications for care: the elderly trauma patient will be weaker than a younger counterpart, and nutrition will need to be provided early, with the glucose intolerance of elderly people borne in mind.

Antibiotic prophylaxis in eyes with filtration blebs: survey of glaucoma specialists, microbiological study, and recommendations

PURPOSE

Bleb-related endophthalmitis is a major late complication of filtration surgery. The purpose of this study was to determine the ophthalmic practic patterns regarding long-term antibiotic prophlaxis in eyes with filtration blebs, and the effect of long-term antibiotic usage on conjunctival bacterial flora.

METHODS

A mail survey of members of the American Glaucoma Society (AGS) was undertaken. In addition. 41 patients who had filtation surgery and received long-term topical antibiotic therapy in one eye only had conjunctival cultures performed in both eyes.

RESULTS

Of the responding members of the AGS, only 6% routinely prescribed long-term antibiotic prophylaxis, 28% prescribed therapy in selected cases only, and 66% did not employ antibiotic prophylaxis. Although more physicians than not had observed endophthalmitis in patients not receiving antibiotic therapy, it was evident that antibiotic prophylaxis did not guarantee that endophthalmitis would not develop in a filtered eye. A total of 49 organisms were isolated from the conjunctiva of eyes receiving antibiotic prophylaxis and 52 organisms were isolated from eyes not receiving antibiotic prophylaxis. There was no statistically significant difference in the types of organisms isolated.

CONCLUSION

Long-term antibiotic prophylaxis does not appear to be a common practice among glaucoma specialists in this country, and it cannot be depended upon as a fail-safe method to prevent bleb-related endophthalmitis. Furthermore, long-term antibiotic usage does not appear to alter the conjunctival flora. Of paramount importance are early detection and treatment of bleb-related infections. Critical in this regard is patient education. Recommendations to minimize the development of endophthalmitis in filtered eyes are reviewed.

Research, practice and the Cochrane Collaboration

The Cochrane Collaboration coordinates the efforts of health care professionals and researchers around the world to prepare, maintain and disseminate systematic reviews of health care research. In carrying out the first two tasks the collaboration employs a rigorous method for analysing the findings of randomized controlled trials; this method was developed in the 1980s and has undergone continual improvement since then. The collaborators believe their work will consolidate and make available the accumulated results of sound research assessing the effectiveness of health care interventions and thus steer health care professionals and consumers toward the right treatments and help guide research into new therapies. Since the collaboration began, in 1993, Cochrane centres have been set up in the British Isles, Canada, Denmark, Italy, the Netherlands and the United States, and many new Cochrane review groups have been registered. Canadian scientists have played an important role in the collaboration. They have prepared and maintained systematic reviews, hosted the collaboration's second annual colloquium and are currently in the vanguard of efforts to facilitate the dissemination of collaboration documents. Although the collaboration uses new modes of communication it has not abandoned traditional ones. Nor has it underestimated the work that remains to be done to bring review findings to the attention of health care providers. Early indications suggest, however, that the collaboration's basic message about the importance of evidence-based practice is getting through.

Veterans worry that unexplained medical problems a legacy of service during Gulf War

Some Canadians who served in the military in the Persian Gulf 4 years ago complain of a range of symptoms commonly described as Gulf War syndrome. Although the syndrome is not recognized as a clinical entity, symptoms include fatigue, lack of sleep, depression, cognitive problems, rashes, bone aches, lassitude, lack of motivation, forgetfulness, mood changes irritability and diarrhea. The medical branch of the Department of National Defence has established programs to inform, guide diagnosis and reach out to symptomatic veterans of the Persian Gulf conflict. Civilian physicians who provide similar care to military personnel who participated in the conflict are invited to call the medical branch (613 996-3752) for further information.

Enhanced antenatal detection of group B streptococcus colonization

OBJECTIVE

To improve culture methods for the detection of group B streptococcus colonization.

METHODS

This study prospectively compared the standard culture medium, a blood agar plate, to a selective culture medium, Todd Hewitt broth with antibiotics, and compared vaginal culture with rectal culture at the first prenatal exam.

RESULTS

Of the 383 vaginal swabs received for evaluation of the two culture media, 78 (20.4%) were positive for group B streptococcus. The detection rates of the blood agar plate method and the Todd Hewitt broth with antibiotics were 64.1 and 97.4%, respectively. Using the Todd Hewitt broth with antibiotics, an additional 94 patients were cultured vaginally and rectally. Twenty-nine (30.9%) had positive cultures. The rate of detection was 58.6% for the vaginal culture, 89.7% for the rectal culture, and 100% for both culture sites combined.

CONCLUSION

These data indicate that culture detection of group B streptococcus can be improved by using both a selective broth medium and a dual vaginal and rectal culture.

What happens to donated blood?

Pursuing their chief work--gathering, processing and distributing blood--the blood donor centres of the Canadian Red Cross Society follow standard operating procedures like those in place at the Ottawa centre. Here, recruitment staff and volunteers work to recruit donors to meet needs at a time when the number of donors is falling. When they register, donors must show proof of identity. Each receives a permanent identification number that is linked to the numbers assigned to the units of blood each donates and to the date the unit was collected and the centre that collected it. Donors must answer questions about health and high-risk activity, and the blood of those who report high-risk activity is not accepted. Units are screened by automated instruments for syphilis, hepatitis B and C, HIV types 1 and 2, and human T-cell leukemia virus. Units with a negative test result are broken down into components for use in hospitals. A reactive test result prompts quarantining of the unit and a second screening test. If this test result is also reactive, a sample of the unit is sent to the National Testing Laboratory for confirmatory testing, and the unit is discarded. Once it has the results of the confirmatory test, the centre contacts the donor. Blood is now considered a drug. Red Cross practices in Canada and around the world have been changing since 1989 to reflect this.