Teaching tips for clinical faculty from the Zen tradition

BACKGROUND AND OBJECTIVES

Teachers of family medicine may improve their skills by examining teachers from other disciplines and cultures. The teaching traditions of Zen might be adapted to medical education. Zen teachers work to eliminate restrictive preconceptions about themselves, their teaching roles, and their students. They strive to encounter their students with their minds and their perceptions clear and to remain ever open to moments of spontaneity and creativity. Examples of how these principles may be used in medical education are presented.

Expression of B1 and B2 bradykinin receptor mRNA and their functional roles in sympathetic ganglia and sensory dorsal root ganglia neurones from wild-type and B2 receptor knockout mice

Bradykinin has been implicated in nociception and inflammation. To examine the relative significance of B1 and B2 bradykinin receptor subtypes in sympathetic and sensory ganglia, the electrophysiological effects of bradykinin analogues and the expression of receptor subtype mRNA were examined in wild-type and "B2 knockout" mice from which the B2 receptor gene had been deleted. In wild-type mice the B2 receptor agonist bradykinin depolarized superior cervical ganglia (SCG) and activated inward currents in dorsal root ganglia (DRG) neurones. Responses to the B1 receptor agonist, [des-Arg10]-kallidin, were seen only in SCG that had been pre-treated with interleukins and the peptidase inhibitor captopril, but not in DRG neurones. The up-regulation of responses to [des-Arg10]-kallidin and substance P were blocked by indomethacin and, thus, were dependent upon cyclo-oxygenase activity. The effects of bradykinin were abolished in SCG and DRG's from B2 knockout mice and this was correlated with the absence of B2 receptor mRNA in ganglia from these animals. However, despite the presence of B1 receptor mRNA in interleukin treated SCG from B2 knockout mice, no depolarizing effects of the B1 receptor agonist [des-Arg10]-kallidin were observed. The successful elimination of bradykinin responses and B2 mRNA in sympathetic and sensory ganglia from B2 knockout mice, confirms that B2 receptors are the predominant functional bradykinin receptor subtype in these tissues and that B1 receptor mRNA is expressed in both sympathetic and sensory ganglia from these animals.

Persistent osteopenia after recovery from anorexia nervosa

OBJECTIVE

Osteopenia is a known complication of anorexia nervosa. Most studies have focused on the features of the illness which predict bone complications. The few reports on recovery have been conflicting, with some studies suggesting restoration of normal bone mass with recovery from anorexia nervosa, while others suggest that the improvement may only be partial. This is the first report of bone density in a long-term recovered group.

METHOD

We measured bone density in the hip and lumbar spine in 18 recovered women, using dual energy X-ray absorptiometry.

RESULTS

We found an unexpectedly high incidence of osteopenia, with 14 of 18 women affected. Duration of amenorrhea was the best predictor of reduced bone density. An index of the duration of recovery, relating it to the duration of illness, was also highly correlated with outcome.

DISCUSSION

Our findings have implications, both for the individual and for the economic burden to society. We suggest that the use of oral contraceptives in women recovering from anorexia nervosa needs further investigation. Additional longitudinal studies are clearly warranted.

Coadministration of glyburide and minoxidil, drugs with opposing effects on potassium channels

INTRODUCTION

Adenosine triphosphate (ATP)-sensitive potassium (K+) channels are modulated by drugs, so that they are opened by vasodilators such as minoxidil but are closed by hypoglycemic agents such as glyburide (glibenclamide). Animal studies and in vitro evidence suggests that the coadministration of drugs with opposing effects on K+ channels attenuates their pharmacodynamic effects.

METHODS

To investigate whether this important pharmacodynamic interaction occurs in humans, we administered 5 mg minoxidil, 2.5 mg glyburide or both in a double-blind fashion to nine healthy subjects. Glucose and insulin responses during an intravenous glucose tolerance test (0.3 gm/kg) were measured and blood pressure was recorded for 8 hours. In an additional four subjects the effect of 5 mg glyburide on the hypotensive effect of 5 mg minoxidil was examined.

RESULTS

None of the parameters of glucose metabolism differed significantly when subjects received glyburide alone, minoxidil alone, or glyburide with minoxidil. Minoxidil or minoxidil in combination with 2.5 mg glyburide resulted in a similar significant decrease in blood pressure compared with the response to glyburide alone. The hypotensive effect of minoxidil was smaller in the four subjects who received the higher dose of glyburide, but significant hypoglycemia (blood glucose concentration < 60 mg/dl) occurred in three of the four subjects.

CONCLUSION

We conclude that, in healthy volunteers, the coadministration of 2.5 mg glyburide and 5 mg minoxidil does not result in attenuation of the blood pressure-lowering effect of minoxidil. The smaller hypotensive response in four subjects who received 5 mg glyburide and 5 mg minoxidil suggests the possibility of a dose-related drug interaction. Studies with strict clamping of blood glucose concentrations will be required to address this possibility.

Chromosomal localization of the human and mouse hyaluronan synthase genes

We have recently identified a new vertebrate gene family encoding putative hyaluronan (HA) synthases. Three highly conserved related genes have been identified, designated HAS1, HAS2, and HAS3 in humans and Has1, Has2, and Has3 in the mouse. All three genes encode predicted plasma membrane proteins with multiple transmembrane domains and approximately 25% amino acid sequence identity to the Streptococcus pyogenes HA synthase, HasA. Furthermore, expression of any one HAS gene in transfected mammalian cells leads to high levels of HA biosynthesis. We now report the chromosomal localization of the three HAS genes in human and in mouse. The genes localized to three different positions within both the human and the mouse genomes. HAS1 was localized to the human chromosome 19q13.3-q13.4 boundary and Has1 to mouse Chr 17.HAS2 was localized to human chromosome 8q24.12 and Has2 to mouse Chr 15. HAS3 was localized to human chromosome 16q22.1 and Has3 to mouse Chr 8. The map position for HAS1 reinforces the recently reported relationship between a small region of human chromosome 19q and proximal mouse chromosome 17. HAS2 mapped outside the predicted critical region delineated for the Langer-Giedion syndrome and can thus be excluded as a candidate gene for this genetic syndrome.

Identification of novel mutations in the human EXT1 tumor suppressor gene

Hereditary multiple exostoses (EXT) is a genetically heterogeneous bone disorder caused by genes segregating on human chromosomes 8, 11, and 19 and designated EXT1, EXT2 and EXT3, respectively. Recently, the EXT1 gene has been isolated and partially characterized and appears to encode a tumor suppressor gene. We have identified six mutations in the human EXT1 gene from six unrelated multiple exostoses families segregating for the EXT gene on chromosome 8. One of the mutations we detected is the same 1-bp deletion in exon 6 that was previously reported in two independent EXT families. The other five mutations, in exons 1, 6, 9, and the splice junction at the 3' end of exon 2, are novel. In each case, the mutation is likely to result in a truncated or nonfunctional EXT1 protein. These results corroborate and extend the previous report of mutations in this gene in two EXT families, and provide additional support for the EXT1 gene as the cause of hereditary multiple exostoses in families showing linkage to chromosome 8.

The clinical role of the nurse teacher: an exploratory study of the nurse teacher's present and ideal role in the clinical area

This paper describes a study which aimed to explore the present and ideal role of the nurse teacher in the clinical area from the perspective of: nurse teachers; ward sisters/charge nurses; staff nurses and students nurses undertaking the 'traditional' and Project 2000 programmes of training. The study adopted a qualitative design. Findings from this study demonstrate that the clinical role of the nurse teacher lacks clarity, however, clear criteria emerged as to how trained nurses and student nurses perceived the ideal role. Nurse teachers' role in assuring the quality of the clinical learning environment emerged as a major area of criticism. It was suggested that, if nurse teachers adopted a clinical role that was primarily concerned with supporting clinically based nurses in their teaching role, this served to assure the quality of students' clinical learning experience. In conclusion, it is suggested that for nurse teachers to meet the needs of trained nurses and student nurses in the clinical area, the role must be diverse and flexible. Attempts to prescribe a unimodel approach to deliver the service should be avoided. Rather, the role must be negotiated between teachers, clinical nurses and students, and constructed in a way that best meets the needs of all parties concerned.

Establishing a community network for recruitment of African Americans into a clinical trial. The African-American antiplatelet stroke Prevention Study (AAASPS) experience

A major aspect of a clinical trial is the ability to successfully recruit patients. There is a paucity of information concerning the nuances of recruiting study patients, especially those from minority communities. As minorities generally have been underrepresented in the health-care system, they may be less likely to participate in clinical trials or other studies. Thus, a strategy is needed to overcome this potential shortfall. One of our solutions has been the development of a community network to help disseminate information about our program. We believe that a key aspect has been the involvement of community members during pre-trial planning, community awareness programs, and our Community Advisory Panel. We also believe that it may be a major error to bring a health-care initiative unannounced into a targeted community without extensive pre-program planning in cooperation with that community. As our community awareness scheme suggests (Figure), there are many possible avenues to heighten awareness about a health-care program. While the church remains an important institution for religious and cultural activities in the African-American community, we have found that the news, television, and radio media also can be a powerful source for spreading awareness. Thus, we recommend creating awareness about an initiative through a "grassroots" approach of church and community organizations, along with a global approach through news, television, and radio media. As part of the awareness promotion campaign, it must be emphasized that the study is safe and provides benefits to enrollees. The success of health programs is largely dependent on community acceptance, which must be established in the pre-program planning stages of the initiative. This concept of obtaining community approval and acceptance prior to program initiation is not a new one, nor does it exclusively apply to the African-American community. Community leaders and members need to have a vested interest in such a program and a sense of empowerment. Through this type of communication, patient enrollment and community satisfaction can be substantial. Such success can serve as a springboard for other targeted health-care studies or programs in high-risk communities.

The growth hormone response to apomorphine at 4 days postpartum in women with a history of major depression

We have examined the responsiveness of dopamine sensitive neurones in the postpartum period in woman with a history of major depression who are at high risk of experiencing a recurrence of illness in the postpartum period. Fourteen women were assessed at 36 weeks of pregnancy and during the 3 months following delivery, using the Schedule for Affective Disorders and Schizophrenia, including its change version. They were not depressed at initial assessment. Five of the 14 women went on to experience a postpartum relapse (2 major depressive disorder, 2 generalised anxiety disorder, 1 panic disorder). On the fourth day postpartum, i.e., before relapse, the growth hormone response to the dopamine agonist apomorphine was measured as an index of the functional state of hypothalamic dopamine D2 receptors. Women who subsequently relapsed had a significantly greater growth hormone response to apomorphine than those who remained well. This was particularly marked in women with anxiety/panic. The development of increased sensitivity of hypothalamic dopamine D2 receptors in the postpartum period appears to predict the onset of depressive and anxiety disorders.

GP-based memory aid group benefits clients and carers

A memory aid group was run for people with memory difficulties and their carers in a local health centre. It aimed to develop coping strategies that carers and clients felt they could put into practice in their own homes. While the numbers in the initial study were small, the group outcome suggested that providing a more localised service, linking mental health specialists and local nursing practitioners had advantages.

How should very low birthweight babies best be managed in Papua New Guinea?

Short-term outcome in very low birthweight babies has never been closely examined in Papua New Guinea. A cohort of neonates born over a year at Port Moresby General Hospital was followed from birth to death or discharge. Intrauterine growth retardation was an important contributor to low birthweight. Simple, inexpensive care resulted in respectable survival figures. Improving antenatal surveillance will have much more impact in reducing mortality in this group in the future than trying to emulate sophisticated and costly western neonatal care.

Isolation and characterization of metastatic variants from human transitional cell carcinoma passaged by orthotopic implantation in athymic nude mice

PURPOSE

These studies were designed to develop an orthotopic model for human bladder cancer and to isolate variant metastatic cell lines.

MATERIALS AND METHODS

The human bladder cancer cell line 253J was implanted into the muscular wall of the bladder of athymic nude mice. By in vivo recycling, we selected for 2 variant cell lines: 253J B-V, a bladder line isolated after 5 serial passages in the bladder, and 253J lung-IV, established from a lung tumor nodule that was recycled through the bladder.

RESULTS

These 2 cell lines showed enhanced tumorigenicity, as measured by a decreased latent period, and rapid growth as compared with the parental cell line. Moreover, orthotopic implantation of these cell lines resulted in metastasis to the lungs. These in vivo-selected, metastatic cell lines exhibited unique karyotypic alterations, increased anchorage-independent growth, overexpression of basic fibroblast growth factor, altered expression of adhesion molecules and the ability to migrate through Matrigel.

CONCLUSIONS

This reproducible model of human bladder cancer offers the opportunity to study cellular properties associated with tumor progression and metastasis and is suitable for the evaluation of new therapeutic strategies for invasive bladder cancer.

Isolation and characterization of metastatic variants from human transitional cell carcinoma passaged by orthotopic implantation in athymic nude mice

PURPOSE

These studies were designed to develop an orthotopic model for human bladder cancer and to isolate variant metastatic cell lines.

MATERIALS AND METHODS

The human bladder cancer cell line 253J was implanted into the muscular wall of the bladder of athymic nude mice. By in vivo recycling, we selected for 2 variant cell lines: 253J B-V, a bladder line isolated after 5 serial passages in the bladder, and 253J lung-IV, established from a lung tumor nodule that was recycled through the bladder.

RESULTS

These 2 cell lines showed enhanced tumorigenicity, as measured by a decreased latent period, and rapid growth as compared with the parental cell line. Moreover, orthotopic implantation of these cell lines resulted in metastasis to the lungs. These in vivo-selected, metastatic cell lines exhibited unique karyotypic alterations, increased anchorage-independent growth, overexpression of basic fibroblast growth factor, altered expression of adhesion molecules and the ability to migrate through Matrigel.

CONCLUSIONS

This reproducible model of human bladder cancer offers the opportunity to study cellular properties associated with tumor progression and metastasis and is suitable for the evaluation of new therapeutic strategies for invasive bladder cancer.

Hydrometrocolpos and segmental colonic dilatation in a girl with megacystis-microcolon-intestinal hypoperistalsis syndrome

OBJECTIVE

To report a case of a newborn female infant noted to have features of the megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) with the additional features of hydrometrocolpos and segmental colonic dilatation and review the literature.

METHODOLOGY

The details of the case were collated and compared with the previous published experience with this condition.

RESULTS

Thus far there have been 58 previous cases of MMIHS described, only four of which have had colonic dilatation. A number of concurrent anomalies have been described, but not the hydrometrocolpos or dysmorphic features seen in this patient.

CONCLUSION

This case appears to be MMIHS with additional features not previously recorded.

Neuroepidemiology of vascular and Alzheimer's dementia among African-American women

To better understand risk factors for Alzheimer's disease and vascular dementia, demographic, medical, and other epidemiological factors were compared for 83 African-American women with Alzheimer's disease and 46 with vascular dementia. Overall, the risk-factor profiles for Alzheimer's disease and vascular dementia were similar to those in other studies. However, Alzheimer's patients had a high frequency of hypertension and a relatively high frequency of diabetes mellitus. The presence of such risk factors raises the possibility that there is a vascular component to the dementia in these African-American women with Alzheimer's disease. Neuropathological studies are needed to help answer this question.

Regulation of the ribosomal-RNA gene-expression in fibroblasts isolated from different human or murine tissues

Ag-NOR stainings of the fibroblastic cultures derived from skin, lung and kidney of mice and humans have shown differential regulation of rRNA gene expression. Ag-NOR activities were found to be highest in the fibroblasts derived from the lung and the lowest in the skin-derived metaphases from both mice and humans and they were intermediate in the fibroblasts of kidney from both these species. Our observations indicate further that fibroblasts derived from different tissues are different not only in producing organ-specific growth factors but also in differential expression of ribosomal cistrons. This difference can also explain why orthotopic implantation of human tumor cells into nude mice is preferential compared with ectopic implantation in tumor take and metastasis.