Biomedical subjects
J Wade
Publications and source records attributed to J Wade.
How many general surgeons do you need in rural areas? Three approaches to physician resource planning in southern Manitoba.
OBJECTIVE: To assess critically the results of using three different approaches to planning for the number of general surgeons in rural areas. DESIGN: Estimates of the number of general surgeons needed using a ratio approach, a and a population-needs-based approach. SETTING: Rural southern Manitoba. OUTCOME MEASURE: Number of general surgeons needed. RESULTS: The ratio approach supported the recruitment of 7.8 to 14.5 additional general surgeons to rural southern Manitoba. The repatriation approach suggested that the area might support five additional general surgeons, if residents could be persuaded to undergo their surgery closer to home. The population-needs-based approach suggested that the health status of area residents was similar to that of residents of other areas of the province and that they had a higher rate of surgery than residents of other areas; no additional surgeons were apparently needed. CONCLUSIONS: Each method has certain advantages, and none is necessarily useful in isolation. Hence, the most effective approach to planning for general surgeons is likely a combination of all three methods. Other factors that may be important include the type of payment structure and the need for professional groups to monitor variations in rates of surgery.
Functional testicular tissue does not masculinize development of the zebra finch song system.
Current theories of sexual differentiation maintain that ovarian estrogen prevents masculine development of the copulatory system in birds, whereas estrogen derived from testicular androgens promotes masculine sexual differentiation of neuroanatomy and sexual behavior in mammals. Paradoxically, some data suggest that the neural song system in zebra finches follows the mammalian pattern with estrogenic metabolites of testicular secretions causing masculine development. To test whether the removal of estrogen from males during early development would prevent the development of masculine song systems, zebra finches were treated embryonically with an inhibitor of estrogen synthesis. In addition, this treatment in genetic female zebra finches induced both functional ovarian and testicular tissue to develop, thus allowing the assessment of the direct effects of testicular secretions on song system development. In males, the inhibition of estrogen synthesis before hatching had a small but significant effect in demasculinizing one aspect of the neural song system. In treated females, the song systems remained morphologically feminine. These results suggest that masculinization of the song system is not determined solely by testicular androgens or their estrogenic metabolites.
Rapid screening of taxol metabolites in human microsomes by liquid chromatography/electrospray ionization-mass spectrometry.
Liquid chromatography with an electrospray ionization (ESI) interface has been applied to study the anticancer drug taxol and its metabolites after incubation with human hepatic microsomes. The parent drug and its metabolites were monitored in the positive-ionization mode. Since ESI gave only quasi-molecular ions for taxol and its analogues, collision-induced dissociation experiments were carried out in order to generate fragment ions, by increasing the cone voltage at the ESI source. The product-ion mass spectra of taxol and its metabolites contained diagnostic fragment ions, which enabled the presence of hydroxylated and deacetylated metabolites of taxol to be established.
Selection of transplant donors based on MHC microsatellite data.
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Selection of transplant donors based on MHC microsatellite data.
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Comparison between an ophthalmic optician and an ophthalmologist in screening for diabetic retinopathy.
The best method of screening for diabetic retinopathy is still debated: fundus photography, general practitioners, hospital physicians and ophthalmic opticians have been advocated. This study compared the performance of an ophthalmic optician with an ophthalmologist, both using mydriatic and slit lamp biomicroscopy and direct ophthalmoscopy. A total of 474 eyes of diabetics in a single group practice were examined by both practitioners at their annual check. There was total agreement about presence or absence of retinopathy in 366 eyes (77%). Although the optician diagnosed less background diabetic retinopathy (83 versus 123 eyes) and diabetic maculopathy (47 eyes versus 63 eyes), he would have referred 20 of 26 eyes with moderate or severe maculopathy and 33 of 36 eyes with moderate or severe background retinopathy: sensitivities of 0.77 and 0.92 respectively. This compares favourably with previous studies and we suggest that ophthalmic opticians with suitable training would be an effective body to screen for diabetic retinopathy.
Neither testicular androgens nor embryonic aromatase activity alters morphology of the neural song system in zebra finches.
A variety of sexual dimorphisms exist in zebra finches, both in the central nervous system and in the periphery. For example, male zebra finches sing to court females, whereas females do not normally sing. In parallel, the brain regions that control song contain a variety of male-biased sexual dimorphisms, and the vocal organ (syrinx) is larger in males than in females. It is thought that some, if not all, of these sex differences are caused by differential hormone secretion by the testes and ovaries of developing birds. However, the effects on sexual differentiation of altering the hormonal environment of birds after hatching have been ambiguous. We have found that treating embryonic female zebra finches with fadrozole, a potent aromatase inhibitor, can induce testicular tissue to develop in addition to normal ovarian tissue. This study documents the function of that testicular tissue in females by showing that it secretes androgens in adulthood, produces sperm, and causes the androgen-sensitive syrinx to enlarge. However, that functional testicular tissue has no effect on the neural song system of females; the brain regions remain completely feminine. Therefore, these results suggest that endocrinologically active testicular tissue alone is not responsible for the dramatic morphological sex differences in the zebra finch song system.
Crusted ("Norwegian") scabies in a specialist HIV unit.
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Sexual differentiation of the brain in songbirds.
The brain regions that control song in zebra finches are much larger in males, who sing, than in females, who do not. Two major theories have been proposed to explain sexual differentiation of the neural song circuit. The 'mammalian' theory suggests that sex steroid secretions of the tests cause masculine development in males. The 'avian' theory suggests that ovarian secretions induce feminine patterns of development in females. Although experimental evidence provides some support for the mammalian theory, neither theory comfortably predicts the outcomes of experiments that bear on the mechanisms of sexual differentiation. In particular, it has been relatively difficult to block sex steroid synthesis and action in genetic males in a way that prevents masculine neural differentiation. Moreover, genetic females that possess large amounts of testicular tissue can have a feminine neural song circuit, suggesting that testicular secretions are not solely responsible for the masculine patterns of differentiation. The results indicate that new theories are needed to explain sexual differentiation of the song system.
Small bowel flora and bacterial translocation in potential small bowel transplant donors.
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Aromatase and 5 beta-reductase activity in cultures of developing zebra finch brain: an investigation of sex and regional differences.
Estrogen treatment of hatchling female zebra finches causes the masculine development of singing behavior and of the telencephalic brain regions involved in the control of song. However, early estrogen treatment of males also blocks masculine development of copulatory behavior, presumably controlled by diencephalic regions. In an effort to determine whether the differences in estrogen action are related to sex and regional differences in androgen metabolism (estrogen synthesis or androgen inactivation), we measured aromatase and 5 beta-reductase activity in dissociated-cell cultures made separately from the telencephalon, diencephalon, and also cerebellum of hatchling zebra finches under a variety of conditions. Cultures from all three brain regions express high levels of aromatase and 5 beta-reductase activity. Comparisons between telencephalic and diencephalic cultures of the activity and kinetics of aromatase suggest that the telencephalic cultures convert androgen to estrogen more efficiently than diencephalic cultures, which might be important in the differential action of estrogen in the two brain regions. However, the activity of neither aromatase nor 5 beta-reductase was significantly different between the sexes in either telencephalic or diencephalic cultures. Thus, comparisons between the sexes do not support the idea that differences in posthatching aromatase or 5 beta-reductase activity account for the pattern of sexual differentiation of the song and copulatory systems.
Phase II study of amonafide in the treatment of patients with advanced squamous cell carcinoma of the head and the neck. An Illinois Cancer Center study.
Amonafide (nafidimide), a synthetic organic compound with an inhibitory effect on cellular replication, was used in a phase II study conducted by the Illinois Cancer Center in order to assess its efficacy and toxicity in advanced or recurrent squamous cell cancer of the head and neck. Eligible patients had received no more than one prior adjuvant or neoadjuvant chemotherapy, had normal bone marrow, renal and hepatic function, ECOG performance status of 0-2, and bidimensionally measurable disease. Eligible patients were administered amonafide at a starting dose of 300 mg/m2 for five consecutive days every 3 weeks with dose escalation or de-escalation according to established hematologic criteria in the absence of disease progression. Nineteen of 22 entered patients were evaluable for response and all patients were evaluable for toxicity. Eleven of 19 patients achieved stable disease. Median time to progression after start of treatment was 57 days, for the 18 patients for whom the date of progression is known. There were no partial or complete responses. Hematologic toxicity was dose limiting with grade 3-4 neutropenia in 50 percent of patients and 4 deaths associated with neutropenic sepsis. Non-hematologic toxicity was mild to moderate with nausea and vomiting predominating. In this study, amonafide was a myelotoxic, inactive treatment in advanced/recurrent head and neck cancer. Further use in head and neck cancer appears unwarranted.
Needle localization breast biopsy with reduction mammaplasty.
Breast pathology may be found during preoperative mammagraphy prior to reduction mammaplasty. When nonpalpable lesions are found, a decision must be made: to proceed with the reduction or to biopsy the lesions prior to the reduction. We describe a patient with bilateral breast lesions who underwent bilateral needle-localized biopsies during reduction mammaplasty. Good communication between the radiologist and surgeon is essential for success. The suspicious lesion must be divided from the remaining breast specimen for adequate specimen mammagraphy. The advantage is that both procedures can be done during one anesthetic dose.
An analysis of predictors of long-term cadaveric renal allograft survival.
To determine factors predictive of long-term graft function in patients treated prophylactically with an antilymphocyte antibody, 670 first cadaveric adult renal transplant procedures performed between 1985 and 1991 were reviewed. The actuarial 1- and 5-year patient survival in this group was 95% and 87% respectively, and graft survival was 84% and 70% respectively. The final analysis was based on a study group of 635 patients which excluded 28 patients who lost grafts to early technical failures and 8 patients who were not induced with an antilymphocyte preparation. Multivariate analysis showed that 5-year graft survival was lower in patients with delayed graft function (p = 0.0001), in those who had an acute rejection episode in the first 6 months post-transplant (p = 0.0001), recipients greater than 55 years of age at the time of transplant (p = 0.0001), in patients who were highly sensitized at the time of transplant (p = 0.0331) and, finally, in those who received a graft from an older donor (p = 0.044). The 209 patients with delayed graft function had a 16% lower long-term graft survival than 425 patients with early graft function (62% vs. 78% respectively at 5 years). One or more rejection episodes in the first 6 months post-transplant (329 patients) reduced long-term graft survival by 13% compared to those who did not have a rejection episode (67% vs. 80% respectively at 5 years).(ABSTRACT TRUNCATED AT 250 WORDS)
Planning the future academic medical centre.
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Post-hatching inhibition of aromatase activity does not alter sexual differentiation of the zebra finch song system.
Hatchling zebra finches were treated with fadrozole, an aromatase (estrogen synthesis) inhibitor, to test whether estrogen is required for normal masculine development of the song system. Injections on posthatching days 1-30 had no effect on the volumes of the robust nucleus of the archistriatum (RA) and area X or on neuron soma size in RA and high vocal center (HVC) measured on day 31. These results argue against the importance of estrogen in masculinization of the song system in males after hatching.