The Duke Minority Medical Student Summer Fellowship: one program's attempt to attract minority residents

Despite numerous Federal and private funding programs aimed at increasing the numbers of underrepresented minorities in medicine, the participation of minority groups in the medical profession remains low and shows little sign of improvement. With the goal of improving minority representation in our primary care residency program, the Minority Medical Student Summer Fellowship started in July 1990. The program's purpose is to give minority medical students positive exposure to primary care and attract them back for residency training. In this four-week elective, students participate in seminars with our primary care residents, see patients in a variety of clinics, and complete a project. Key implementation issues include support of the medicine chairman and dean, funding, and malpractice coverage for the students. Program evaluation from the first two students rated the clinic experiences higher than the seminar sessions and the independent project. Both students stated our fellowship made them more likely to train at this medical center should they enter a primary care program. Implications for other programs are listed.

Can physician education lower the cost of prescription drugs? A prospective, controlled trial

OBJECTIVE

To determine whether an educational program featuring a drug cost manual can assist physicians in reducing their patients' out-of-pocket prescription drug expenses.

DESIGN

Prospective controlled trial.

SETTING

A general internal medicine-teaching clinic in a university hospital.

PARTICIPANTS

Fifty-one medical interns.

INTERVENTION

Thirty-one interns received a manual of comparative drug prices annotated with prescribing advice, two feedback reports, and weekly cost-oriented prescribing reminders. A control group concurrently participated in a manual-based educational program on cholesterol management.

MEASUREMENTS

Copies of 3012 prescriptions written over 8 months were analyzed.

MAIN RESULTS

Intervention group physicians prescribed less expensive drugs within classes of drugs. The change in drug price score per prescription was -0.15 (95% Cl, -0.27 to -0.04; P = 0.01). A score of 3 was assigned to the most expensive, 2 was assigned to intermediate-priced, and 1 was assigned to the least expensive drug or drugs in the class. An increase of 0.74 months' (Cl, 0.49 to 0.98; P less than 0.001) supply of medication was dispensed per prescription, reducing dispensing fees. The program was well accepted by the physicians.

CONCLUSION

This relatively simple educational intervention can help physicians to reduce their patients' drug expenses and may serve as a model for incorporating cost information into the routine practice of medicine.

Quantitative analysis of the outpatient oral case presentation: piloting a method

OBJECTIVE

To measure the content of oral outpatient case presentations and to assess the correlation of objective assessments of this content with subjective ratings provided by the clinic attending physician.

DESIGN

Blinded assessment via audiotape of 36 oral case presentations of new patient evaluations by 23 medical residents.

SETTING

Outpatient general medical clinic.

PARTICIPANTS

Duke University Medical Center medical residents during their outpatient rotation.

MEASUREMENTS AND MAIN RESULTS

Important deficiencies were found in oral case presentation content. Specifically, psychosocial data were often missing (employment history) was mentioned in 28% of presentations; illicit drug use, in 17%; household social structure, in 11%; sexual history, in 6%). An assessment and a plan were mentioned only 56% and 69% of the time, respectively. No correlation was seen between an objective "content score" and the attending physician's subjective rating of the quality of the presentation (r = 0.09).

CONCLUSIONS

1) The outpatient care presentation can be quantitatively assessed in a simple, straightforward manner; 2) outpatient case presentations have important deficiencies in content; and 3) preceptors' evaluations of case presentations may be based upon factors other than content of the presentation.

Breast cancer screening in older women: practices and barriers reported by primary care physicians

Annual mammography, in combination with clinical breast examinations, can reduce mortality from breast cancer. However, surveys of both patients and physicians suggest that mammography is underutilized. This study examined whether physicians' reported breast cancer screening practices and barriers to mammography varied with patients' age. Data from 576 primary care physicians (internal medicine, family/general practice, and obstetrics/gynecology) who participated in a mailed statewide survey were analyzed. Physicians reported screening elderly women significantly less often than younger women, regardless of family history of breast cancer. With the exception of medical specialty, physicians' demographic and practice characteristics were not associated with reported screening practices. However, physicians' knowledge and beliefs about breast cancer in older women were associated with reported screening practices. When analyzing barriers to ordering mammography, cost to the patient was viewed as a barrier for women of all ages, and pain was viewed as a greater barrier for younger women; otherwise, physicians consistently believed that their elderly patients faced considerably more barriers compared with younger women. Further investigation is required to examine why primary care physicians report age-related differences in both breast screening and barriers to mammography.

Genetic suppression demonstrates interaction of TonB protein with outer membrane transport proteins in Escherichia coli

Energy-coupled reactions of the Escherichia coli outer membrane transport proteins BtuB and Cir require the tonB product. Some point mutations in a region of btuB and cir that is highly conserved in TonB-dependent transport proteins led to loss of TonB-coupled uptake of vitamin B12 and colicin Ia, whereas binding was unaffected. Most other point mutations in this region had no detectable effect on transport activity. Mutations in tonB that suppressed the transport defect phenotype of these btuB mutations were isolated. All carried changes of glutamine 165 to leucine, lysine, or proline. The various tonB mutations differed markedly in their suppression activities on different btuB or cir mutations. This allele specificity of suppression indicates that TonB interacts directly with the outer membrane transport proteins in a manner that recognizes the local conformation but not specific side chains within this conserved region. An effect of the context of the remainder of the protein was seen, since the same substitution (valine 10----glycine) in btuB and cir responded differently to the suppressors. This finding supports the proposal that TonB interacts with more of the transport proteins than the first conserved domain alone.

Conditional hyporecombination mutants of three REC genes of Saccharomyces cerevisiae

We have isolated and characterized three conditional hyporecombination mutants, rec1-1, rec3-1 and rec4-1, that define three REC genes of Saccharomyces cerevisiae required for spontaneous general mitotic interchromosomal recombination. Each MATa/MAT alpha rec/rec diploid is deficient in mitotic single site gene conversion, intragenic recombination, intergenic recombination and sporulation at the restrictive temperature (36 degrees C). The rec1-1 mutation also confers conditional enhanced sensitivity to the killing effects of X-rays. The rec1-1 and rec3-1 mutations have been mapped to chromosome VII. The rec1-1, rec3-1 and rec4-1 mutations exhibit complementation at 36 degrees C for both mitotic recombination and sporulation.

The initiation and maintenance of callus cultures

Plant tissues grown in vitro provide an ideal research tool for the study of a wide range of aspects of plant science. For example, they have been used in the investigation of both primary and secondary metabolism, cytodifferentiation, morphogenesis, plant tumor physiology, and the formation of plant hybrids via protoplast fusion techniques. Plant tissue culture is also being increasingly adopted for the commercial propagation of plants.

Organogenesis in callus culture

Plant cells can be totipotent, i.e., each cell may be capable of developing into an entire plant when provided with the correct environmental stimuli. Research during the last 30 yr has demonstrated that successful organogenesis in callus cultures can be achieved by the correct choice of medium components, selection of a suitable inoculum, and control of the physical environment (1). The manipulation of plant growth regulator concentration is probably the most widely used technique for the induction of organogenesis, and this methodology has formed the basis of the propagation of commercially important plants via tissue culture in recent years (2).

Functional outcome following spinal cord injury. A comparison of specialized spinal cord injury center vs general hospital short-term care

The functional outcomes of 185 patients with spinal cord injuries undergoing rehabilitation who were initially treated in a specialized short-term care unit (center patients) were compared with those of 153 patients initially treated in general hospitals (noncenter patients). After stabilization, all patients were admitted to the Rehabilitation Institute of Chicago (Ill) and received the same rehabilitation program. The groups were comparable in terms of demographic, injury, and medical characteristics at the time of rehabilitation center admission, but the duration from injury to rehabilitation was more than twice as long for noncenter patients. While center patients were discharged from the rehabilitation center at equivalent functional skill levels, their daily rate of functional gains during the rehabilitation center stay was significantly greater than that of noncenter patients although the length of stay at the rehabilitation center was comparable for the two groups. These results support the practice of specialized short-term spinal cord injury care as a means of enhancing rehabilitation outcome.

Photosensitization of human glioma cells by chalcogenapyrylium dyes

Chalcogenapyrylium (CP) dyes which are specifically activated by red and near infrared light (600-900 nm) were examined as potential photosensitizers for photochemotherapy of malignant gliomas. Eleven CP dyes of varying chemical structure and redox potential were evaluated for selective toxicity against glioma and normal skin fibroblast cell cultures both before and after light activation. Eight of eleven CP dyes exhibited differential toxicity to tumor over fibroblast cells at dye concentrations of 1.0 microM. Dose dependent toxicity was seen both in the dark and after laser light activation. The toxicity of two of the CP dyes was significantly enhanced by photoactivation with 800 nm light. The CP dyes that absorb light maximally between 775 and 850 nm, in the range of excellent light penetration through brain, appear to be promising candidates as photosensitizers for treating malignant brain tumors.

The effect of a chalcogenapyrylium dye with and without photolysis on mitochondrial function in normal and tumor cells

A chalcogenapyrylium dye 8b, which is under investigation for the photodynamic therapy of malignant gliomas (brain tumors), was evaluated for inhibition of mitochondrial function both before and after exposure to laser light of 800 nm. Neoplastic and normal cells forced to use mitochondrial substrates were killed by the light-activation of intracellular 8b as well as exposure to classic mitochondrial inhibitors, rotenone and sodium azide. Correspondingly, cells in glucose-rich media showed little decrease in viability due to the photolysis of intracellular 8b or the presence of mitochondrial toxins. The toxicity of 8b without light activation was found to be the same regardless of the cell's energy source. Measurement of cellular ATP generated during treatment also showed the photolysis of intracellular 8b to be more inhibitory towards mitochondrial function than the unactivated parent compound. We conclude that the chalcogenapyrylium dyes localize to the mitochondrion and that photoactivation results in mitochondrial injury.

Screening mammography in the elderly: a case-control study

This case-control study tested the hypothesis that elderly women with metastatic breast cancer were previously screened less than controls. Cases included women over 60 years old who had metastatic breast cancer; the tumor registry provided controls. Identical criteria yielded comparable groups (cases = 109, controls = 211) receiving primary care at this tertiary center. Radiology and medical records were examined for mammograms; these were blindly categorized "diagnostic," "screening," or "indeterminant." The major, unexpected finding was that less than 6% of controls had ever had screening mammography. The associations between screening and metastatic cancer (odds ratios) suggest a beneficial effect of screening: OR/0.73 for ever screened and OR/0.71 if screened within the year of cancer diagnosis. All confidence intervals include one; however, low screening participation leaves this study with little power. The major implication is that despite the current recommendations, the elderly are not being included in screening mammography programs.

Interstitial laser photochemotherapy of rhodamine-123-sensitized rat glioma

The effect of interstitial laser photochemotherapy with the mitochondrial-specific intravital dye rhodamine-123 (Rh-123) was studied using a malignant rat glioma model system (RT2). Tumors were transplanted subcutaneously into the flank of athymic mice and into the cerebrum of adult rats. The Rh-123 photosensitization was produced by direct intratumoral injection of Rh-123 into the mouse RT2 flank tumors and by intravenous Rh-123 administration to adult rats with implanted RT2 intracerebral tumors. Intratumoral irradiation with 150 mW of argon laser light for an exposure time of 15 minutes was performed using a conical sapphire-tipped quartz optical fiber. Control groups of animals received either no treatment, Rh-123 injections, or administration of 150 mW of argon laser light for 15 minutes. Both flank and intracerebral tumors showed progressive diminution in size after treatment with Rh-123 photochemotherapy. There was no evidence of tumor recurrence in 60% of Rh-123 photochemotherapy-treated tumors. Recurrences in tumors treated with Rh-123 photochemotherapy usually appeared at the periphery of the original tumor at 10 days after treatment. Histologically, photochemotherapy-treated intracerebral tumors showed progressive shrinkage with increasing tumor necrosis over time. The finding of residual or recurrent tumor at the periphery of the original tumor mass suggests that the lack of penetration of the blue-green (argon) light was responsible for preventing complete tumor ablation. Our results suggest that Rh-123 photochemotherapy can destroy malignant gliomas in vivo; however, the poor penetrability of the photoactivating blue-green light may limit the effectiveness of this treatment for large or extensively invasive tumors.

Cloning and characterization of tetM gene from a Ureaplasma urealyticum strain

We have cloned a 4.9-kilobase (kb) HincII fragment which contains a tetracycline resistance determinant (tetM) from the chromosome of Ureaplasma urealyticum. The 4.9-kb HincII fragment contains DNA in addition to the structural gene, is closely related to the previously characterized 5.0-kb fragment from pJI3, and contains no normal ureaplasmal DNA sequences.

Need for insulin therapy in type II diabetes mellitus. A randomized trial

To identify patients with type II diabetes mellitus for whom insulin therapy is most beneficial, we conducted a randomized controlled trial in the general medicine clinic of a university hospital. Asymptomatic, obese, insulin-treated patients were given diet and diabetes education and, in half of these patients, insulin therapy was withdrawn. Over six months, patients developing hyperglycemic symptoms or acetonemia were counted as study failures. Failure criteria developed in 13 of 25 insulin-withdrawal patients, at a median of four weeks after withdrawal, compared with two of 24 control subjects. Elevated stimulated glucose levels predicted the need for insulin therapy. Hyperglycemia worsened in insulin-withdrawal patients who did not meet study failure criteria, but it improved in control patients. Study patients were insulin deficient as shown by low baseline C peptide values (0.43 +/- 0.05 nmol/L). The prompt metabolic decompensation precipitated by insulin withdrawal suggests that insulin-deficient patients may benefit from insulin therapy and may need it to prevent symptomatic hyperglycemia.

Differential retention of rhodamine 123 by avian sarcoma virus-induced glioma and normal brain tissue of the rat in vivo

The time course of uptake, retention and clearance of the cationic lipophilic dye, rhodamine 123 (Rh123), within the central nervous system was qualitatively evaluated in rats. Weanling rats were injected intracerebrally with avian sarcoma virus, which induced malignant gliomas in situ before injection of Rh123. Comparison was made of the amount of fluorescence of Rh123 within the normal cerebral cortex, myelinated tracts of the brain, meninges, choroid plexus, and neoplastic foci at 1, 4, 8, 12 and 24 hours after intravenous injection. Fluorescence microscopy was utilized to identify tissues containing the dye. Normal neuropil did not contain Rh123 at any of the time periods studied. Gliomas retained the dye at 1, 4, 8 and 12 hours, with increasing uniformity of distribution and decreasing intensity of fluorescence over this time period. Fluorescence was not detected at 24 hours within the neoplastic tissues, but was evident at all time periods studied within the choroid plexus. The specific retention of Rh123 by malignant glioma and by the choroid plexus in vivo suggests that Rh123 may be useful for photochemotherapeutic treatment of brain neoplasms and disorders of the choroid plexus.

Hyperthermia from interstitial laser irradiation in normal rat brain

This study examined both the effect of variations in optical fiber tip and in light wavelength on laser-induced hyperthermia in rat brain. Normal rat brains were exposed to argon laser light (454-514.5 nm) delivered through an intracerebral end-emitting (bare-tipped) or a diffusion-emitting (sapphire-tipped) optical fiber probe. Interstitial thermistor probes recorded temperatures after thermal equilibration at varying distances from the emitting source. The end-emitting fiber produced significantly (P less than 0.05) higher elevations in tissue temperature than the diffusion-emitting fiber at the same laser power output. This is due to the smaller surface area (1.2 mm2 versus 7.8 mm2) of the end-emitting fiber, which results in a greater rate of energy delivery to tissue adjacent to the fiber tip. Changes in intracerebral temperature measurements were also recorded at similar distances from a diffusion-emitting fiber at a continuous total laser power output of 150 mW for light wavelengths of 454-514.5 nm, 700 nm, and 750 nm and at a total laser output of 1.1 W for 1,060 nm. Variations in brain tissue temperature with distance from the laser emission source were compared for each laser group with the tissue temperature profile generated by a radiofrequency (wavelength 600-625 m) interstitial probe. Similar temperature changes were found for all visible wavelengths near the probe, suggesting that the thermal response of brain adjacent to an interstitial laser fiber is primarily dependent upon the rate of energy delivery and not upon wavelength. The thermal profile versus distance from the light source depends mostly upon the level of temperature rise near the interstitial laser fiber tip and not the wavelength of laser light used. These results have important implications in interstitial applications of laser for hyperthermia and photochemotherapy.

The resident leaves the clinic: the effects of changing physicians on appointment-keeping behavior

To understand the effect that termination of an established physician-patient relationship has on patient attendance patterns in a medical clinic, appointment scheduling and patient attendance were measured for 210 patients before and after 11 senior resident physicians left the clinic. There was no significant change in appointment scheduling, although the number of unscheduled or "drop-in" visits increased (p = 0.02). Likewise, patient attendance patterns did not differ between study periods. Overall the termination of an established relationship between an internist and a patient in this hospital-based general medicine clinic had no effect on appointment scheduling and patient attendance.

Aneurysm formation after low power carbon dioxide laser-assisted vascular anastomosis

A series of 125 adult rats was operated upon to perform end-to-end anastomosis of the femoral artery using either a carbon dioxide laser or conventional suture technique. Vessels were inspected at varying time intervals grossly and microscopically. Overall, the rate of aneurysm formation for the laser group was 18.6% (21/113). Late aneurysm formation (1 week or longer after operation) was seen in 29.8% (20/67) of the laser group. No aneurysms were noted in the suture group either early or late. Histological examination of the laser-joined vessels revealed widespread necrosis and loss of elastic elements in the media. In time, abnormal spindle-shaped cells appeared in this damaged layer. Histologically, the aneurysms were indistinguishable from those reported in human cerebral aneurysm cases. This technique provides an experimental aneurysm model and lends support to the acquired/degenerative theory of human cerebral aneurysm formation.

Light dosimetry in brain tissue: an in vivo model applicable to photodynamic therapy

The intensity of blue-green (488 nm) and red (633 nm) light as a function of increasing distance from an implanted laser fiberoptic source in the brains of anesthetized rats was measured. There was significant (90%) attenuation of the light intensity for both 488 nm and 633 nm at a distance of 2.5 mm from the intracerebral laser light-emitting source. At greater distances from the light-emitting source that corresponded to areas in the cerebral cortex, there was greater attenuation of light intensity for increasing distance with 488 nm than with 633 nm because of the increased vascularity of the cortical mantle and absorption of 488 nm by hemoglobin. When hematoporphyrin derivative was given intravascularly, there was increased attenuation of 633 nm through the cerebral cortex that was similar to that seen for 488 nm in normals. Direct assessment of light intensity in living tissue, which we have shown is possible in this report, will aid in our understanding and interpretation of the histological changes that occur following photodynamic therapy.