Acute coronary syndromes in treatment-naïve black South africans with human immunodeficiency virus infection.

BACKGROUND: HIV patients on protease inhibitors have greater risk of acute coronary syndromes (ACS) but little is known about treatment-naïve patients. METHODS AND RESULTS: Authors conducted a prospective single-center study from Soweto, South Africa, comparing the clinical and angiographic features of treatment-naïve HIV positive and negative patients with ACS. Between March 2004 and February 2008, 30 consecutive treatment-naïve HIV patients with ACS were compared to the next HIV-negative patient as a 1:1 control. HIV patients were younger (43 +/- 7 vs. 54 +/- 13, P = 0.004) and, besides smoking (73% vs. 33%, P = 0.002), had fewer risk factors than the control group with less hypertension (23% vs. 77%, P = 0.0001), diabetes (3% vs. 23%, P = 0.05), LDL hyperlipidemia (2.2 +/- 0.9 vs. 3.0 +/- 1.2, P = 0.006), and other coronary risk factors (7% vs. 53%, P = 0.0001). HDL was lower in the HIV group (0.8 +/- 0.3 vs. 1.1 +/- 0.4, P = 0.001). Atherosclerotic burden was lower in the HIV group with more normal infarct-related arteries (47% vs. 13%, P = 0.005) but a higher degree of large thrombus burden (43% vs. 17%, P = 0.02). Stents were used to a similar degree in HIV and control patients (30% vs. 37%, P = 0.78) with more target lesion revascularization in the HIV group (56% vs. 0%, P = 0.008). CONCLUSION: Treatment-naïve HIV patients with ACS are younger and have fewer traditional risk factors than HIV-negative patients. HIV patients have less atherosclerotic but higher thrombotic burden which may imply a prothrombotic state in the pathogenesis of ACS in these patients.

The bonding effectiveness of five luting resin cements to the IPS Empress 2 all ceramic system.

BACKGROUND: Variolink II is the only resin cement used for bonding IPS (Ivoclar Porcelain System) Empress 2 ceramic restorations. Alternative luting resin cements need to be investigated for their bonding effectiveness with the IPS Empress 2 ceramic. OBJECTIVES: To determine the shear bond strength (SBS) and the effect of thermocycling, on the bonding effectiveness, of five resin cements to IPS Empress 2 ceramic. MATERIALS AND METHODS: The projecting surfaces of one hundred ceramic discs were ground wet on silicone carbide paper. The specimens were divided into 5 groups of 20. The resin cements were bonded to the prepared ceramic surfaces, in the form of a stub. The specimens were stored under distilled water at 37 degrees C in an oven for 24 hours. Ten specimens in each group were thermocycled for 300 cycles between 5 degrees C and 55 degrees C. All the specimens were stressed to failure in an Instron Materials Testing Machine. RESULTS: The results were subjected to a one-way analysis of variance (ANOVA). Statistically similar mean SBS values were grouped using the Bonferroni (Dunn) multiple comparison test. The means for the non-thermocycled group were: 26.21, 19.41, 17.69, 17.43, and 15.76. The means for the thermocycled group were: 22.90, 15.72, 14.34, 13.96 and 13.45. The differences between the means were highly significant (p < 0.0125). CONCLUSIONS: The shear bond strength of Variolink II and Rely XARC to IPS Empress 2 ceramic was effective. Thermocycling had a significant effect on the mean SBS values of Calibra. Thermocycling had no significant effect on the mean SBS values of the other resin cements.

Flexibility of technopolymer clasps compared with cobalt-chromium and titanium clasps.

Patients often cite lack of retention and poor aesthetics as reasons for not wearing their partial dentures. Traditional metal alloy clasps have been shown to exert forces on abutment teeth that exceed those capable of producing tooth movement. In addition, metal display on anterior teeth is often unacceptable. The technopolymer materials are purported to have superior flexibility and exert less force than the metals. This study compared the flexibility and forces produced by technopolymer clasps with those exerted by cobalt-chromium and titanium clasps. The results showed that the technopolymer clasps were up to ten times as flexible as the metal clasps, and they returned to their pretest dimensions after being stretched. In addition, they exerted forces on the abutment teeth that fall within the range of those considered safe for use. This coupled with their pleasing aesthetics makes them suitable for use on periodontally compromised teeth, those with deep undercuts and on anterior teeth.

An 8-year assessment of maxillofacial prosthetic patients treated in a Department of Prosthetic Dentistry.

The Department of Prosthetic Dentistry at the University of the Witwatersrand, Johannesburg, serves as a referral centre for maxillofacial prosthetic patients from the surrounding general hospitals and local private clinics. This places a time and financial constraint on the department. The aim of this study was to establish the number of new patients seen annually, the causative factors associated with the various types of defects, the treatment provided and the cost per patient in terms of clinical hours and prosthesis fees. The data were taken from the records of patients treated in the maxillofacial prosthetics clinic during an 8-year period, from January 1991 to December 1998. The total number of new patients was calculated and the data were collated according to the year in which treatment commenced. Results were tabulated according to the number of new cases in each group, the aetiology of the defects, prosthetic treatment provided and the costs in terms of clinical hours and prostheses. The results of this study indicate that there is a need for a specialised Maxillofacial Prosthetic Unit. Although the present fee schedule needs to be revised, there is still a need for a substantial amount of state subsidy.

The elastic limit of nickel-containing and nickel-free cobalt-chromium circumferential clasp arms.

The purpose of this study was to compare the flexibility and rigidity of the retentive arms of cast circumferential clasps prepared from two nickel-containing alloys (Vitallium and Wironit) with a nickel-free alloy (Biosil). Standardised wax patterns were adapted to 30 specially prepared refractory casts. Ten of these waxed casts were sent to each of three commercial laboratories that specialize in making castings from each of the alloys to be tested. A tensile tester was used to test each one of the finished clasps for deflection at the elastic limit and for load at 0.5 mm deflection. An exploratory analysis of the data by means of a multivariate analysis of variance was followed by Fisher's least significant test that identified specific differences between test specimens. It was found that nickel-containing and nickel-free alloys were not significantly different in respect of flexibility and rigidity.

The flexibility of titanium clasps compared with cobalt-chromium clasps.

Retention of a partial denture depends on the amount of undercut engaged on an abutment tooth and the flexibility of the clasp. Flexibility is influenced by clasp length and the denture base material. Titanium clasps are purported to have greater flexibility than cobalt-chromium cast clasps which should enable them to engage deeper undercuts or be used where shorter clasp arms are needed such as on premolar teeth. This study investigated the flexibility of cast titanium clasps with three commonly used cobalt-chromium clasps through comparative measurements of their tip deflections and yield strengths. The results showed that the titanium clasps were significantly (P < 0.05) more flexible than the cobalt-chromium clasps. However, all four materials were found to be flexible enough to engage an undercut of 0.25 mm without exceeding their yield strengths.

Use of custom-made conformers in the treatment of ocular defects.

The loss of an eye is often followed by scar tissue contracture. The purpose of this article is to describe a procedure for fabricating acrylic resin ocular custom-made conformers to maintain socket size and contour. These custom-made ocular conformers act as an interim measure and as valuable diagnostic indicators of problems experienced by the patients. While stock conformers merely maintain the socket size and prevent scar tissue contractures, the custom-made conformers can also be used to enlarge unfavorably small sockets, stimulate eyelid movement, aid hygiene, help the clinician develop the final shape for the definitive prosthesis, and reduce the amount of postinsertion adjustments needed. These advantages and the ease of fabrication make custom-made conformers a viable initial treatment option in patients with ocular defects.

Cyanosis and clubbing in a patient with iatrogenic Lutembacher syndrome.

A patient with rheumatic mitral and aortic stenosis is described in whom balloon dilatation of the mitral valve was complicated by an iatrogenic atrial septal defect with a small left to right shunt. Over the course of 4 years, the patient became progressively cyanosed and clubbed and was found to have reversed the shunt across the atrial septal defect due to the occurrence of severe tricuspid stenosis. The tricuspid valve was successfully dilated with re-establishment of a net left to right shunt. This syndrome, the first of its kind, should be appropriately termed the reversed Lutembacher syndrome.

Frequency of prosthetic valve-related complications with very low level warfarin anticoagulation combined with dipyridamole after valve replacement using St. Jude Medical prostheses.

The safety of a very low level of anticoagulation combined with dipyridamole in a rheumatic population (mean age 31 +/- 13 years) with the St. Jude Medical (SJM) prosthesis has not yet been tested. Furthermore, no data are available on the safety of relatively infrequent monitoring of anticoagulation levels and of the necessity for different therapeutic targets according to valve position, number of risk factors, and other baseline risk factors for thromboembolism. In this study, the performance of the SJM prosthesis was tested using a target international normalized ratio (INR) of 2.0 to 2.5 combined with dipyridamole 300 mg/day applied uniformly to all patients. Clinical, biochemical, and echocardiographic data were acquired prospectively in 200 consecutive patients at 3-month intervals. Follow-up (mean 27 +/- 13 months) was complete in 95% of patients. Thirteen patients died (2.9%/patient year). Severe left ventricular dysfunction was the cause of death in 10 of 13 patients. Probability of survival (Kaplan-Meier) was 0.92 at 36 months and of event-free survival 0.84 at 36 months. The median INR was 2.0 +/- 0.9. Valve obstruction did not occur, and there were 3 thromboembolic events (0.6%/patient year). Incidence of bleeding was 1.6%/patient year (n = 7) and was major (hemorrhagic stroke) in 1 (0.2%/patient year). Thus, the SJM prosthesis performs very well despite the use of very low level warfarin anticoagulation combined with dipyridamole. A 3-month assessment of the anticoagulation level is safe. Left ventricular dysfunction rather than valve-related complications is the leading cause of mortality in this population.

Imaging of pulmonary vascular disease by intravascular ultrasound.

To assess the ability of intravascular ultrasound (IVUS) to image changes in the pulmonary arterial wall associated with pulmonary hypertension (PHT), 10 subjects requiring diagnostic right and left heart catheterization were studied. In addition to measurements of pulmonary artery pressure and pulmonary vascular resistance and pulmonary angiography, when indicated, all underwent simultaneous IVUS imaging in the pulmonary arterial system using a 20 MHz ultrasound transducer mounted on a 2 mm diameter catheter. Four patients had normal pulmonary artery pressures and 6 had varying degrees of PHT. Satisfactory ultrasound images were obtained in 9 out of the 10 patients. In those with normal pulmonary artery pressures ultrasound showed a thin vessel wall with no distinction between separate layers. In patients with systemic PHT, a three-layered vessel wall was apparent and areas compatible with intimal proliferation were seen. In a patient with pulmonary embolic disease areas consistent with mural thrombus were detected at sites of luminal narrowing on the pulmonary angiogram. IVUS is capable of imaging some of the morphological changes in the wall of the pulmonary artery known to occur in longstanding PHT and may therefore become a useful adjunct to haemodynamic measurements and pulmonary angiography for the in vivo assessment of pulmonary vascular disease.

Bovine internal mammary artery as a conduit for coronary revascularization: long-term results.

Graft patency after coronary artery bypass grafting depends largely on the choice of conduit. Because an increasing number of patients have insufficient or poor-quality autologous material, there is a need for a suitable synthetic graft that is readily available and easy to handle and that has good long-term patency. Early results suggest that the bovine internal mammary artery graft may meet these criteria. We have used a total of 26 such grafts in 18 patients. Postoperative angiography has been performed in 19 grafts in 14 patients, 3 to 23 months after operation; of these grafts, 3 are currently patent (15.8%, compared with 85.7% and 75.0% patency for native internal mammary artery and saphenous vein grafts in the same patients). We report the results of clotting studies and an analysis of lipid status. These patients do not, however, appear to represent any atypical group, either in terms of coagulopathy, native coronary artery size, or the type of vessel disease. Nevertheless, our poor results contrast markedly with the early enthusiasm reported from other centers.

Repair of asymptomatic aortic valve disease during other cardiac surgery.

Repair of asymptomatic aortic valve disease was performed in 12 patients (9 female, 3 male, mean age 57.5 years) undergoing other cardiac surgery. Stenosis was the predominant aortic valve lesion in 7 (group A) with a mean gradient of 33.4 mmHg and regurgitation of mean grade 1.4 was predominant in 5 (group B). Cusp debridement +/- commissurotomy was performed in 9; commissural resuspension in 6 and repair of cusp perforation in 2. Perioperative transoesophageal echocardiography was used to assess the adequacy of repair in 4 patients. Prospective precordial echocardiographic follow-up is complete (mean 4.3 months). In group A there has been a significant reduction is peak aortic pressure gradient (33.4 vs 22.1 mmHg, p less than 0.05) and in cusp thickness (2.25 to 1.64 mm, p less than 0.05). In group B the degree of incompetence has improved in 3 of the 5 patients. Three patients have worsened valve disease following repair; in all these there was mixed valve disease of rheumatic origin. Aortic valve repair of asymptomatic disease during other cardiac surgery is a feasible technique which does not accelerate the disease process in the short term. Long-term follow-up is in progress to assess the prognosis of this preventive intervention.

Percutaneous balloon dilatation of the mitral valve in patients who were unsuitable for surgical treatment.

OBJECTIVE: To assess the effects on haemodynamic function and symptoms of percutaneous balloon dilatation of mitral stenosis in patients unable to undergo surgical treatment because of associated medical/cardiac problems. DESIGN: A review of clinical outcome in 28 patients (of 108 undergoing balloon dilatation of the mitral valve) who were unsuitable for surgery. SETTING: A tertiary cardiac referral centre: some patients referred were from other cardiac centres in Scotland. PATIENTS: 28 patients judged by cardiac surgeons to be unsuitable for valve replacement or valvotomy because of respiratory disease (15 patients), nonmitral cardiac disease (6), multi-organ impairment (5), psychiatric problems (1) or dense intrathoracic adhesions (1). INTERVENTIONS: Percutaneous anterograde balloon dilatation of the mitral valve with polyethylene/polyvinyl balloons in 20 patients and the Inoue balloon in eight patients. MAIN OUTCOME MEASURES: Haemodynamic variables were measured before and immediately after mitral valve dilatation. Patient survival and symptom class (New York Heart Association) were followed for a year after the procedure. RESULTS: Dilatation at the mitral orifice was achieved in all cases. The mean (SD) pressure drop across the valve fell from 13.9 (5.3) to 5.6 (2.5) mm Hg, cardiac output rose from 3.18 (1.02) to 3.96 (2.5) l/min, and valve area increased from 0.78 (0.32) to 1.58 (0.56) cm2. The procedure was well tolerated by most patients, even those with metabolic/electrolyte disturbance, severe obstructive airways disease, myocardial impairment, and coronary disease. In three patients a small shunt developed at the atrial level: none developed severe mitral reflux. The two patients who required assisted ventilation died soon after the procedure and in one patient with severe coronary artery disease myocardial infarction developed and she died in cardiogenic shock. Early symptomatic improvement was reported by 23 of the 25 survivors, though the increase in exercise capacity was often limited by their non-mitral disease. At one year follow up a further 6 patients had died because of their additional disease: 15 continued to show symptomatic improvement. CONCLUSIONS: Percutaneous balloon dilatation of the mitral valve is a useful new option in patients who are too ill to undergo cardiac surgery; but longer term benefit can be limited by the associated disease.

Mitral balloon valvuloplasty for patients aged over 70 years: an alternative to surgical treatment.

We report the results and one-year follow-up of 20 elderly patients (age range 70-82 years) with severe rheumatic mitral stenosis treated by mitral balloon valvuloplasty (MBV). All 20 were breathless at rest despite treatment with diuretics and digoxin. At cardiac catheterization, successful dilatation was achieved in 17 patients: mean transvalvular mitral gradient fell by 45%, mean cardiac output rose by 24% and mean valve area increased by 76%. There was no procedure-related mortality. At one month, 15 patients had experienced an improvement in symptoms of at least one New York Heart Association class and, at one year, ten had maintained this improvement. Three patients proceeded to mitral valve replacement because of a suboptimal symptomatic result. Mitral balloon valvuloplasty can be successfully performed with significant symptomatic benefit in frail elderly patients unfit for surgery and may also be offered to other selected elderly patients as an alternative to surgical treatment.

Sarcoid dactylitis in black South African patients.

Six black South Africans with sarcoid dactylitis are described. By the term sarcoid dactylitis we mean sarcoid involvement of the bone and soft tissue of the fingers. Three of the six patients developed dactylitis during the course of chronic sarcoid. These patients had multisystem disease. In all three patients dactylitis developed after the diagnosis of sarcoid was established. However, in the other three patients dactylitis was the presenting feature of sarcoidosis, and none of these patients had evidence of chronic fibrotic sarcoid elsewhere. This finding is at variance with the observation that bony sarcoid is always a feature of chronic, poor prognosis, fibrotic sarcoid of all organ systems; these patients may form a sub-group with bony involvement and good prognosis. The significance, however, of this latter localized presentation of sarcoid is that clinically and histologically it is easily confused with tuberculoid leprosy and has been misdiagnosed.

Pyoderma gangrenosum and ulcerative colitis in black South Africans. Case reports.

Two patients with pyoderma gangrenosum and ulcerative colitis are described. To our knowledge this is the first report of such an association in Blacks. The unusual vesicopustular form of pyoderma gangrenosum was well demonstrated by one patient who also responded remarkably to clofazimine. The associations, pathological findings and therapy are briefly reviewed. Colectomy may ameliorate the skin lesions when conventional therapy is unsuccessful.

Atypical pulmonary sarcoidosis. A case report.

The pulmonary manifestations of sarcoidosis are varied. This report describes a patient with rapidly progressive pulmonary sarcoidosis which had several unusual features and presented with acute pneumonia with air bronchograms on chest radiographs. Gallium-67 scanning and serum angiotensin-converting enzyme estimations aided in the diagnosis and in determining the response to steroid therapy.