Hypertension in Haitians: results of a pilot survey of a public teaching hospital multispecialty clinic

Little is known about hypertension in Haitians. We performed a pilot survey of ambulatory Haitian patients in a multispecialty clinic at a large public teaching hospital. Approximately 10% of the clinic population was of Haitian origin. Clinical data were collected on 88 consecutive Haitian patients. Of these 88, 77 (87.5%) were hypertensive (SBP > or = 140 or DBP > or = 90 mm Hg or taking antihypertensive medication). The characteristics of the hypertensive patients were: age 54.1 +/- 13.0 (s.d.) years; 27 men, 50 women; 12/64 (19%) smoked; 7/63 (11%) used alcohol. Diabetes was present in 21/77 (27%). In patients for whom height and weight were available, obesity was present in 52%. Using JNC V criteria, 18 (23%) had Stage 1, 16 (21%) Stage 2, 18 (23%) Stage 3, and 25 (33%) Stage 4 hypertension. Despite 63/77 (82%) being treated for hypertension, only 20 (26%) were controlled (< 140/< 90 mm Hg). Of those under treatment, 29 were taking one drug; 18 (two drugs); 12 (three drugs); and four (four drugs). Target organ damage was evident in 37 (48%), including coronary artery disease (8), CHF (6), chronic renal failure (15), stroke (9), and LVH by ECG (19). There was evidence of severe noncompliance in 32 (42%). We conclude that in this clinic sample, hypertension was highly prevalent and unusually severe in terms of blood pressure (BP) level, refractoriness to treatment, and target organ consequences. Further studies are indicated.     

Attenuation of neomycin ototoxicity by iron chelation

Increasing evidence suggests that aminoglycoside ototoxicity is mediated by the formation of an aminoglycoside-iron complex and that the creation of this complex is a preliminary step in generation of free radical species and subsequent hair cell death. In this study we have assessed the ability of the iron chelator deferoxamine to attenuate the hearing loss induced by an ototoxic dose of the aminoglycoside neomycin (100 mg/kg per day for 14 days). Experiments were carried out on pigmented guinea pigs weighing 250 to 300 g. Changes in auditory sensitivity were characterized by monitoring shifts in compound action potential (CAP) thresholds, recorded through indwelling electrodes implanted at the round window, vertex, and contralateral mastoid. Results show that animals receiving neomycin alone suffered a mean threshold shift exceeding 35 dB at all test frequencies (2.0, 4.0, and 8.0 kHz) 30 days after initiation of treatment. In comparison, all animals receiving cotherapy of neomycin and deferoxamine (150 mg/kg twice daily for 14 days) maintained their CAP threshold, suggesting significant protection from neomycin ototoxicity. A statistical comparison of treatment groups showed that in the animals receiving cotherapy with neomycin and deferoxamine, deferoxamine produced a significant protective effect against neomycin-induced ototoxicity (P < 0.001). These results provide further evidence of the intrinsic role of iron in aminoglycoside ototoxicity and suggest that deferoxamine may have a therapeutic role in attenuating the cytotoxic action of aminoglycoside antibiotics.     

An in vitro approach for the study of dentinogenesis by organ culture of the dentine-pulp complex from rat incisor teeth

This article focuses on the experiences and role of a tutor while conducting a problem based learning (PBL) exercise to facilitate the learning of biochemistry and molecular biology. A case presentation of sickle cell anemia was used to frame a module. The objective of this experimental exercise was to assess the suitability and effectiveness of problem based learning in the first year of undergraduate medical course and to practice self-assessment by tutors in this new role of a facilitator of learning through small group discussion. A tutor during such a learning session encouraged the students to apply their reasoning to analyze the problem and to develop self-directed learning skills in acquiring the knowledge appropriate to their perceived needs to work on a problem. The tutors ensured that they apply this knowledge in their work with other similar problems that they would encounter later in life.     

Donor factors affecting outcome after pancreas transplantation

In this study, we demonstrated that Px grafts from donors older than 45 years are associated with an increased risk of developing poor glycemic control and premature loss of Px function. Previous studies corroborate our finding that age of the donor is the principal donor characteristic impacting postoperative Px survival. Whereas prior studies also implicated hyperamylasemia as a factor which contributes adversely to outcome, we were unable to demonstrate a significant influence of donor hyperamylasemia on long-term graft survival, although it did correlate with the degree of immediate postoperative pancreatitis and with the need for oral hypoglycemic agents. Similarly, elevated blood glucoses in the donor, which can be a result of many other factors unrelated to the quality of the graft, did not predict a poor outcome in the recipient. NHB donor pancreata did as well as HB pancreata with regards to all postoperative functional parameters. A marginally increased risk of developing major complications was associated with older donors. Despite the frequent use of non-ideal donors, including older and NHB donors, excellent overall Px graft survival can be achieved. Although the quality of the pancreas graft was not directly addressed in this study, we believe irrespective of hyperglycemia or hyperamylasemia, subjective assessment of organ quality by an experienced transplant surgeon is the most important determinant of suitability.     

Cross-sectional area of the mandible

PURPOSE: The anatomy of the mandible was examined by measuring the cross-sectional area (CSA) of multiple regions of 10 fully dentulous hemimandibles to provide a better understanding of regional structural differences that may have implications regarding biomechanical strength, surgical reconstruction, and fracture site frequency. MATERIALS AND METHODS: Fifteen cuts from the condyle to the symphysis were made of each hemimandible (n = 150 cuts). A Zeiss Videoplan digitizer was used to determine the CSA. RESULTS: The total CSA through the condyle was greater than the CSA through the condylar neck. The CSA through the ramus exceeded that of the condylar neck. The total CSA of the midramus was significantly greater than that of the upper ramus. The total CSA at the body, parasymphysis, and symphysis was significantly greater than at the mid-angle. The total CSA of the cortex increased anteriorly; these differences become significant between the condylar neck and the body, parasymphysis, and symphysis. The total CSA, and the CSA of the cortex and spongiosa, remained relatively constant from the inferior angle anteriorly. CONCLUSIONS: Significant differences exist in the CSA at different points, with an increase in the total, cortical, and spongiosal CSA anteriorly from the condylar neck to the angle. The total CSA and the CSA of the cortex and spongiosa remain relatively constant anterior to the inferior angle. These data suggest that bony CSA alone is not the sole factor in determining fracture site frequency.     

Neonatal castration and adult responsiveness to testosterone in male rats: an interstrain comparison

We have previously demonstrated that the spontaneously hypertensive rat (SHR) has a lower central nervous responsiveness to testosterone than its normotensive counterpart the Wistar-Kyoto rat (WKY). The adult psychoendocrine response capacity depends on a neonatal testosterone surge. On that basis, we compared the effects of neonatal endocrine manipulation on the adult responsiveness to testosterone in the SHR, WKY, and yet another breed of Wistar (Wi) male rats. Interstrain differences in testosterone-induced copulatory behavior at three different doses of testosterone propionate (TP) were investigated. Neonatal treatments were as follows: TP (0.25 mg/animal) given on postnatal days (PND) 0, 2, and 4 (SHR and Wi only) or castration PND 0, 10, or 50. Neonatal TP treatment impaired copulatory performance in the adult SHR but not in the Wi. Neonatal castration improved the responsiveness to TP in the SHR but less so in WKY, whereas no evident effects were seen in the Wi. No significant interstrain differences in plasma testosterone were observed 2, 6-12, or 24 h postpartum. The demonstrated interstrain differences suggest not only that the adult responsiveness to testosterone is established on the basis of the neonatal gonadal secretion as such but that this secretion is kept to an optimal level with respect to subsequent hormone-sensitive mechanisms.