Staff recognition and its importance for surgical service delivery: a qualitative study in Freetown, Sierra Leone.

We examined the views of providers and users of the surgical system in Freetown, Sierra Leone on processes of care, job and service satisfaction and barriers to achieving quality and accessible care, focusing particularly on the main public tertiary hospital in Freetown and two secondary and six primary sites from which patients are referred to it. We conducted interviews with health care providers (N = 66), service users (n = 24) and people with a surgical condition who had chosen not to use the public surgical system (N = 13), plus two focus groups with health providers in primary care (N = 10 and N = 10). The overall purpose of the study was to understand perceptions on processes of and barriers to care from a variety of perspectives, to recommend interventions to improve access and quality of care as part of a larger study. Our research suggests that providers perceive their relationships with patients to be positive, while the majority of patients see the opposite: that many health workers are unapproachable and uncaring, particularly towards poorer patients who are unable or unwilling to pay staff extra in the form of informal payments for their care. Many health care providers note the importance of lack of recognition shown to them by their superiors and the health system in general. We suggest that this lack of recognition underlies poor morale, leading to poor care. Any intervention to improve the system should therefore consider staff-patient relations as a key element in its design and implementation, and ideally be led and supported by frontline healthcare workers.

Gastrin stimulates receptor-mediated proliferation of human esophageal adenocarcinoma cells.

The prevalence of esophageal adenocarcinoma in the setting of Barrett's metaplasia continues to increase in Western nations at a rate greater than any other cancer. The trophic properties of gastrin have been documented in gastric, pancreatic and colon cancer cell lines, suggesting a potential role for this regulatory peptide in the growth of these malignancies. The aims of these studies were to identify and characterize the presence of functional cholecystokinin type-2 (gastrin) receptors on the membranes of human esophageal adenocarcinoma cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated the presence of cholecystokinin type-2 receptor transcripts in human esophageal adenocarcinoma cell lines. Competitive binding assays revealed specific binding of gastrin in SEG-1 cells (IC50 of 2.4 x 10(-8) M). This finding was confirmed by laser scanning confocal microscopy through internalization of rhodamine green labeled gastrin heptapeptide in SEG-1 cells. Gastrin caused a dose-dependent increase in proliferation of SEG-1 cells when compared to controls. This effect was abolished by co-incubation with L365,260, a CCK-2-specific receptor antagonist. Gastrin-induced phosphorylation of the p44 and p42 mitogen-activated protein kinases was demonstrated by Western blot analysis. In conclusion, the studied human esophageal adenocarcinoma cell lines possess cholecystokinin type-2 (gastrin) receptors. Receptors bind gastrin, resulting in increased proliferation in SEG-1 cells.

Vasoactive response of isolated pulpal arterioles to endothelin-1.

The vasoactive effect of endothelin-1 applied intraluminally or extraluminally was studied in vitro in isolated perfused porcine pulpal arterioles using a microperfusion system. Pulpal arterioles (outer diameter, 94.2 +/- 2.8 microm, n = 12) were cannulated and perfused at a constant flow rate in an environment-controlled bath on the stage of an inverted microscope. The vessel diameters were measured online. Both intraluminal and extraluminal application of endothelin-1 (10(-16) M to 10(-8) M) induced dose-dependent constrictions, reaching 82.3 +/- 1.7% (n = 12) and 70.5 +/- 1.3% (n = 12) at 10(-8) M, respectively. Nifedipine reversed endothelin-1-induced constriction dose-dependently at 10(-7) M and above. These data demonstrate that endothelin-1 induces calcium-dependent vasoconstriction in porcine pulpal arterioles, with extraluminal application more potent, which seems to reflect the possible modulation of vascular endothelium in the control of vascular tone.

Morphological study of dentin irradiated by solid-state ultraviolet lasers: a comparison of wavelength and repetition rate.

OBJECTIVE: In this study, we examined the surface morphology of dentin after being ablated by the third, fourth, and fifth harmonics of the Nd:YAG laser. The influences of the repetition rate with respect to the wavelength were also investigated. BACKGROUND DATA: Typically, excimer lasers have been used as the primary sources of ultraviolet (UV) laser wavelengths to investigate laser ablation of dentin. In the past decade, developments in nonlinear optical technology have given rise to higher conversion efficiencies of the fourth and fifth harmonics of the Nd:YAG laser. To this end, sufficient energy densities of the fourth and fifth harmonics of the Nd:YAG laser have been generated to ablate dentin. MATERIALS AND METHODS: Thin dentin samples (typically 1 mm) were irradiated by the third, fourth, and fifth harmonics of the Nd:YAG laser. Ablation occurred at repetition rates of 1, 5, 10, and 20 Hz, using similar energy densities for each laser wavelength. An environmental scanning electron microscope was used to assess the resultant surface morphology. RESULTS: Dentine surfaces after 355-nm ablation exhibited plugging at each repetition rate. Similar surfaces were exhibited after 266-nm ablation. "Plugging" over dentine tubules was less obvious after 213-nm laser ablation. The results may highlight the impact of different absorption characteristics of each wavelength. CONCLUSION: Solid-state UV laser ablation of dentin exhibits similar properties to excimer laser ablation. At similar energy densities, the deeper UV laser wavelengths exhibit less "plugging" of dentin tubules, suggesting a lower thermal impact.

Tissue oxygen tension and blood-flow changes in rat incisor pulp with graded systemic hyperoxia.

The role of oxygen in the regulation of the pulpal microcirculation is unknown. This investigation is aimed to measure tissue oxygen tension and blood-flow changes in the pulp of rat lower incisors during graded systemic hyperoxia, and to determine the response of the pulpal vasculature to various oxygen tensions. Twenty-four Sprague-Dawley rats were anaesthetized and artificially ventilated with the appropriate gas mixture. Recessed oxygen-sensitive microelectrodes were used to measure pulpal tissue oxygen tension via a small access cavity filled with saline on the labial surface of the incisor. A laser Doppler flowmeter was used to record pulpal blood-flow. Inspired oxygen was increased stepwise from 20 to 100% in 20% steps. Systemic blood-gas concentrations were measured at each step. Systemic arterial oxygen tension at 100% oxygen ventilation reached 481.2 +/- 30.7% of the baseline at 20% oxygen breathing (n=21). Pulpal tissue oxygen tension did not change significantly whereas pulpal blood-flow fell dose-dependently to 74.6 +/- 5.0% at 100% oxygen ventilation (n=21). Systemic hyperoxia, therefore, induces a significant reduction in pulpal blood-flow whereas pulpal tissue oxygen tension remains relatively stable, indicating an oxygen-dependent local regulatory mechanism.