Blood pressure and heart rate in young thalassemia major patients

The analysis of blood pressure (BP) and heart rate (HR) variability is currently used to investigate the mechanisms responsible for cardiovascular control; therefore, we assessed whether an impairment of 24-h BP and HR profiles and sympathovagal interaction modulating cardiovascular function was present in patients with thalassemia major (TM) in preclinical phase of heart disease. Nine beta-thalassemic patients 18 years old without clinical signs of cardiac failure and 9 age- and sex-matched controls were studied. Twenty-four-hour-ambulatory BP and HR were measured using the SpaceLabs 90207 device. A truncated Fourier series with four harmonics was used to describe the diurnal blood pressure profile. Mean 24-h ambulatory systolic BP, diastolic BP, and mean arterial pressure were significantly lower in TM patients than in normal subjects (P < .05). A significantly higher nighttime HR value was found in TM patients (P < .05). More than 40% of the TM patients did not show a significant diurnal BP and HR rhythm. In TM patients, the overall amplitude of systolic BP, diastolic BP, and HR was significantly lower than in controls (P < .01). The night/day differences of systolic BP, diastolic BP, and HR were significantly lower in TM patients than in normals (P < .01). Furthermore, we performed power spectral analysis on short-term continuous finger BP and HR data in supine position and during passive head-up tilt. Total spectral power of systolic BP was significantly lower in patients than controls (P < .05). Low-frequency (LF) power of systolic BP and diastolic BP and LF/high-frequency (HF) ratio of HR were significantly lower during tilt in TM patients compared to controls (P < .05). High-frequency power of HR was significantly higher in patients than controls (P < .05). The baroreflex gain assessed by alpha-index was the same in supine position but was higher in TM patients during passive tilt (P < .05). An inverse relationship between LF/HF ratio of HR and hemoglobin levels in TM patients was found. Finally, plasma norepinephrine levels were significantly lower in thalassemics (P < .005). In young TM patients in a preclinical stage of heart disease, these findings demonstrated abnormal 24-h BP and HR rhythms and a decreased short-term variability of BP and HR, in particular in the LF range, showing a diminished sympathetic activity.

Secondary osteoporosis

Generalized osteoporosis currently represents a heterogeneous group of conditions with many different causes and pathogenetic mechanisms, that often are variably associated. The term "secondary" is applied to all patients with osteoporosis in whom the identifiable causal factors are other than menopause and aging. In this heterogeneous group of conditions, produced by many different pathogenetic mechanisms, a negative bone balance may be variably associated with low, normal or increased bone remodeling states. A consistent group of secondary osteoporosis is related to endocrinological or iatrogenic causes. Exogenous hypercortisolism may be considered an important risk factor for secondary osteoporosis in the community, and probably glucocorticoid-induced osteoporosis is the most common type of secondary osteoporosis. Supraphysiological doses of corticosteroids cause two abnormalities in bone metabolism: a relative increase in bone resorption, and a relative reduction in bone formation. Bone loss, mostly of trabecular bone, with its resultant fractures is the most incapacitating consequence of osteoporosis. The estimated incidence of fractures in patients prescribed corticosteroid is 30% to 50%. Osteoporosis is considered one of the potentially serious side effects of heparin therapy. The occurrence of heparin-induced osteoporosis appeared to be strictly related to the length of treatment (over 4-5 months), and the dosage (15,000 U or more daily), but the pathogenesis is poorly understood. It has been suggested that heparin could cause an increase in bone resorption by increasing the number of differentiated osteoclasts, and by enhancing the activity of individual osteoclasts. Hyperthyroidism is frequently associated with loss of trabecular and cortical bone; the enhanced bone turnover that develops in thyrotoxicosis is characterized by an increase in the number of osteoclasts and resorption sites, and an increase in the ratio of resorptive to formative bone surfaces, with the net result of bone loss. Despite these findings, the occurrence of pathological fractures in patients with hyperthyroidism is relatively low, and probably due to the fact that deficiencies in bone mass may be reversed by treatment of the thyroid disease. Most, but not all, studies on insulin-dependent diabetes mellitus (IDDM) report an association with osteopenia. In IDDM, the extent of bone loss is usually slight, which helps explain the discrepancy between the frequency of decreased bone mineral density, and the frequency of osteoporotic fractures in long-standing diabetes. Contradictory results have been obtained in non-insulin-dependent diabetes mellitus (NIDDM) patients. Increased rates of bone loss at the radius and lumbar spine were demonstrated either in patients with two-thirds gastric resection and Billroth II reconstruction, or in those with one-third resection and Billroth I anastomosis, and the metabolic bone disease following gastrectomy may consist also of osteomalacia or mixed pattern of osteoporosis-osteomalacia, with secondary hyperparathyroidism. Miscellaneous causes of secondary osteoporosis are also immobilization, pregnancy and lactation, and alcohol abuse.

Blood pressure and heart rate in young thalassemia major patients

The analysis of blood pressure (BP) and heart rate (HR) variability is currently used to investigate the mechanisms responsible for cardiovascular control; therefore, we assessed whether an impairment of 24-h BP and HR profiles and sympathovagal interaction modulating cardiovascular function was present in patients with thalassemia major (TM) in preclinical phase of heart disease. Nine beta-thalassemic patients 18 years old without clinical signs of cardiac failure and 9 age- and sex-matched controls were studied. Twenty-four-hour-ambulatory BP and HR were measured using the SpaceLabs 90207 device. A truncated Fourier series with four harmonics was used to describe the diurnal blood pressure profile. Mean 24-h ambulatory systolic BP, diastolic BP, and mean arterial pressure were significantly lower in TM patients than in normal subjects (P < .05). A significantly higher nighttime HR value was found in TM patients (P < .05). More than 40% of the TM patients did not show a significant diurnal BP and HR rhythm. In TM patients, the overall amplitude of systolic BP, diastolic BP, and HR was significantly lower than in controls (P < .01). The night/day differences of systolic BP, diastolic BP, and HR were significantly lower in TM patients than in normals (P < .01). Furthermore, we performed power spectral analysis on short-term continuous finger BP and HR data in supine position and during passive head-up tilt. Total spectral power of systolic BP was significantly lower in patients than controls (P < .05). Low-frequency (LF) power of systolic BP and diastolic BP and LF/high-frequency (HF) ratio of HR were significantly lower during tilt in TM patients compared to controls (P < .05). High-frequency power of HR was significantly higher in patients than controls (P < .05). The baroreflex gain assessed by alpha-index was the same in supine position but was higher in TM patients during passive tilt (P < .05). An inverse relationship between LF/HF ratio of HR and hemoglobin levels in TM patients was found. Finally, plasma norepinephrine levels were significantly lower in thalassemics (P < .005). In young TM patients in a preclinical stage of heart disease, these findings demonstrated abnormal 24-h BP and HR rhythms and a decreased short-term variability of BP and HR, in particular in the LF range, showing a diminished sympathetic activity.

[IgE levels in cord blood in an area of the Veneto region]

BACKGROUND

Cord blood IgE levels have been studied as a possible marker of allergy in infants but few studies are available in our Region. The aim of this paper was to test IgE levels in cord blood of 60 consecutive newborns in a restricted area of Veneto, to correlate cord blood IgE levels with family history of allergy and to verify the risk of contamination from mother's blood.

METHODS

Cord blood was obtained from 60 consecutive newborns. Immunoglobulin levels (IgG, IgA, IgM, and IgE) were measured in cord blood of newborns and in serum of all mothers. Family history for allergy was previously investigated from the mothers.

RESULTS

IgE were detectable in cord blood of 5 newborns but only 2 of them had positive family history for allergy which was pointed out in 11/60. In one of these cases the contamination of sample from mother's blood was postulated. IgG levels in newborn cord blood were higher than in mothers' blood and it was not related with IgE levels or other investigated factors.

CONCLUSIONS

Only 6.6% of newborns in a restricted area of Veneto region have detectable IgE in cord blood whereas 18.3% of them have positive family history for allergy. Measurable levels of IgE in cord blood are not related with positive family history of allergy and are rarely influenced by mothers' blood contamination.

Modified "T" stenting: a technique for kissing stents in bifurcational coronary lesion

The kissing stenting using a new technique in two patients is reported. A stent was positioned at the ostium of the side branch. Another stent was advanced into the main vessel until the center of the stent was positioned near the origin of the side branch. The stent at the ostium of the side branch was deployed and the balloon and the guidewire were removed from the side branch. Thereafter, the stent in the main vessel was deployed. The follow-up angiogram of those patients showed no restenosis in both the vessels.

Long-term clinical follow-up after successful repeat percutaneous intervention for stent restenosis

OBJECTIVES

This study evaluated the long-term clinical outcome of successful repeat percutaneous intervention after in-stent restenosis.

BACKGROUND

Recurrence of symptoms and angiographic restenosis after stent implantation are observed in 15% to 35% of cases. Repeat percutaneous treatment for in-stent restenosis has been shown to be safe, with high immediate success, but little is known about the long-term clinical outcome.

METHODS

Clinical follow-up (minimum 9 months) was obtained in a consecutive series of 124 patients (127 vessels) presenting with stent restenosis who were successfully treated with repeat percutaneous intervention.

RESULTS

Clinical follow-up was obtained in all 124 patients at a mean [+/-SD] of 27.4 +/- 14.7 months (range 9 to 66); a stress test was available in 88 patients (71%). Recurrence of clinical events occurred in 25 patients (20%) and included death from any cause in 2 patients (2%), target vessel revascularization in 14 (11%), myocardial infarction in 1 (1%) and positive stress test results or recurrence of symptoms (Canadian Cardiovascular Society class I to IV) treated medically in 8 (6%). Cumulative event-free survival at 12 and 24 months was 86.2% and 80.7%, respectively. Significant predictive factors of recurrence of clinical events were repeat intervention in saphenous vein grafts, multivessel disease, low ejection fraction and a < or = 3-month interval between stent implantation and repeat intervention.

CONCLUSIONS

In-stent balloon angioplasty for stent restenosis in native vessels seems to be an effective method in terms of a low long-term clinical event rate.

Coronary stenting after rotational atherectomy in calcified and complex lesions. Angiographic and clinical follow-up results

BACKGROUND

Treatment of calcified (in contrast to simple) lesions with PTCA has been associated with a lower success rate and more procedural complications. Rotablation can improve acute results, but the high restenosis rate remains a problem. The purpose of this study was to evaluate the clinical and angiographic outcome of patients with complex and calcified lesions treated with a combination of rotablation and stenting.

METHODS AND RESULTS

Seventy-five consecutive patients with 106 lesions had rotablation prior to coronary stenting. Intravascular ultrasound-guided stenting was used without subsequent anticoagulation in 93% of patients. Procedural success was achieved in 93.4% of lesions. Acute stent thrombosis occurred in two lesions (1.9%), and subacute stent thrombosis in one lesion (0.9%). Angiographic follow-up was performed in 82.5% of lesions at 4.6 +/- 1.9 months with an angiographic restenosis rate of 22.5%. Clinical follow-up was performed in all patients at 6.4 +/- 3 months; target lesion revascularization was needed in 18% of lesions; Q-wave myocardial infarction occurred in 1.3%, coronary bypass surgery in 4.0%, and death in 1.3%.

CONCLUSIONS

Optimal coronary stenting after rotablation in calcified and complex lesions can be performed with a high success rate, an acceptable rate of procedural complications, and a low rate of stent thrombosis. This approach was associated with a low incidence of angiographic restenosis compared with results usually obtained with other interventional strategies in calcified and complex lesion subsets.

Molecular characterization of G6PD deficiency in Southern Italy: heterogeneity, correlation genotype-phenotype and description of a new variant (G6PD Neapolis)

We report on the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Southern Italy (Campania region). Thirty-one unrelated G6PD-deficient males were analysed at DNA level for the presence of G6PD gene mutations. Nine different G6PD variants were identified, eight of which have already been described (Mediterranean, Seattle, two different A-, Santamaria, Cassano, Union and Cosenza). G6PD Mediterranean, Santamaria, A- and Union were associated with haemolytic episodes. G6PD Seattle, which is polymorphic in several populations, Cassano and Cosenza appeared to be asymptomatic. A new variant (G6PD Neapolis) is reported here. The 467(Pro-->Arg) substitution responsible for G6PD Neapolis is discussed in the light of the current 3D model of human G6PD and in comparison with other natural mutations which occur in the proximity of residue 467.

Fourier analysis of circadian blood pressure profile in secondary hypertension

Different types of statistical methods have been used for circadian blood pressure (BP) rhythm analysis in secondary forms of hypertension. In the present study, we used the two-step statistical approach by Fourier analysis with four harmonics for the parametrization of the diurnal BP pattern in secondary hypertension. In 43 essential hypertensives (EH), eight patients with aldosterone producing adenoma (APA), 25 with idiopathic hyperaldosteronism (IHA), four with glucocorticoid remediable hyperaldosteronism (GRH) and seven with renovascular hypertension (RVH), 24-h ambulatory BP was measured. The diurnal BP and heart rate (HR) rhythm was present in more than 70% of patients with secondary hypertension, without significant differences with EH and despite the attenuation in the degree of the nocturnal BP fall. In conclusion, the statement that secondary hypertension is characterized by an abnormal diurnal rhythm of BP is a gross over-simplification. Our findings suggest that the two-step method with four harmonics Fourier analysis may represent a useful method and a more complete statistical approach to providing circadian parametrization of the 24-h profile in secondary hypertension.

Enhanced expression of glucose-6-phosphate dehydrogenase in human cells sustaining oxidative stress

Recent reports have demonstrated that glucose-6-phosphate dehydrogenase (G6PD) activity in mammalian cells is necessary in order to ensure cell survival when damage is produced by reactive oxygen intermediates. In this paper we demonstrate that oxidative stress, caused by agents acting at different steps in the biochemical pathway controlling the intracellular redox status, determines the increase in G6PD-specific activity in human cell lines of different tissue origins. The intracellular level of G6PD-specific mRNA also increases, with kinetics compatible with the induction of new enzyme synthesis. We carried out experiments in which cells were exposed to oxidative stress in the presence of inhibitors of protein or RNA synthesis. These demonstrated that increased G6PD expression is mainly due to an increased rate of transcription, with a minor but significant contribution of regulatory mechanisms acting at post-transcriptional levels. These results provide new information on the defence systems that eukaryotic cells possess in order to prevent damage caused by potentially harmful oxygen derivatives.

Age-related changes in body composition of healthy and osteoporotic women

OBJECTIVES

The study was carried out to assess age-related changes of body composition and to evaluate the influence of lean and fat mass in bone mineral density of healthy and osteoporotic women.

METHODS

166 healthy women in premenopause (43.2 +/- 6.7 years), 591 healthy postmenopausal women (59.9 +/- 8.1 years) and 373 women with established involutive osteoporosis (66.2 +/- 7.8 years) were evaluated: bone mineral density (BMD) and soft tissue composition (fat mass, lean mass) were measured by a total body Lunar DPX device.

RESULTS

no difference in lean mass was appreciated between the groups. Fat mass was significantly lower in premenopausal women (19.5 +/- 6.5 kg) and osteoporotic patients (18.8 +/- 5.2 kg) than in postmenopausal healthy women (21.8 +/- 5.7 kg). In premenopause weight, soft tissue mass and fat mass increased with age (P < 0.05). In postmenopause, lean mass decreased significantly in healthy women (P < 0.05). Fat mass was lower in the osteoporotics than in normals. Total BMD correlated significantly with fat and lean mass in all groups (P < 0.01). BMD/height ratio correlated significantly with fat mass (P < 0.01), not with lean mass.

CONCLUSIONS

BMD is closely related to fat mass in healthy premenopausal and postmenopausal women, and in osteoporotic patients; osteoporotic patients and healthy premenopausal women are characterized by a lower fat mass than healthy postmenopausal women; fat mass may be considered one of the determinants of bone mass also in involutive osteoporosis.

New approach to quantitative angiographic assessment after stent implantation

The new generation quantitative angiographic systems apply the interpolated technique to calculate the reference diameter at the site of the stenosis by integrating measurements of the segments proximal and distal to the stenosis. After stent implantation these measurements can be misleading as the treated segment, which is frequently larger than the adjacent not stented segments, is included in the measurements. The consequence is an overestimation of the reference diameter and the residual diameter stenosis. The present study was performed to compare this conventional technique of measurement with a new method which excludes the stented segment for the calculation of the reference diameter. Fifty-two lesions treated with poorly radiopaque stents (56% Palmaz-Schatz, 28% NIR, 10% Gianturco-Roubin, 6% Wallstent) expanded at high pressure (> = or 16 atm) were analyzed according to the conventional and stent excluded method. After stent implantation the reference diameter was 3.39 +/- 0.48 mm with conventional measurements and 3.02 +/- 0.45 mm with the stent excluded method (P < 0.05). The corresponding % diameter stenosis was 13 +/- 9 for the conventional technique and 1 +/- 13 for the stent excluded analysis (P < 0.05). The new approach to quantitative coronary analysis after stenting provides higher accuracy in reference diameter calculations and allows a more appropriate matching of stented segments with adjacent normal segments.

Results of a consecutive series of patients receiving only antiplatelet therapy after optimized stent implantation. Comparison of aspirin alone versus combined ticlopidine and aspirin therapy

BACKGROUND

Previous studies have shown that stents can be inserted in coronary arteries of patients who are subsequently treated safely with antiplatelet therapy only (ticlopidine and/or aspirin) with a low incidence of stent thrombosis, provided that stent expansion is adequate and there are no other flow-limiting lesions present. However, it is unknown whether ticlopidine combined with aspirin is superior to aspirin alone in preventing stent thrombosis.

METHODS AND RESULTS

From March 1993 through July 1995, 801 consecutive patients assigned to receive either aspirin therapy alone (ASA, 264 patients, 348 lesions) or a combination of ticlopidine and aspirin (TIC-ASA, 537 patients, 737 lesions) after a successful stent insertion, in most accomplished with intravascular ultrasound guidance, were evaluated retrospectively. At 1 month, there was no difference in the ASA group compared with the TIC-ASA group in the rate of any stent thrombosis (1.9% versus 1.9%; P = 1), subacute stent thrombosis (1.9% versus 1.3%; P = .5), cumulative major adverse clinical events (1.9% versus 2.0%; P = 1), and peripheral vascular complications (0.5% versus 0.2%; P = .3). Medication side effects that required termination of antiplatelet therapy occurred only in 1.9% of patients in the TIC-ASA group (P = .04).

CONCLUSIONS

At 1-month clinical follow-up, stent thrombosis and other adverse clinical outcomes were not significantly different between the ASA and TIC-ASA groups. Medication side effects occurred only in patients treated with ticlopidine. These results provide further evidence of the safety of treatment with antiplatelet therapy only after optimal stent implantation and support the efficacy of aspirin alone in preventing stent thrombosis.

Intracoronary stent implantation in native coronary arteries and saphenous vein grafts: a consecutive experience with six types of stents without prolonged anticoagulation

OBJECTIVE

To analyze the results of implantation of six different intracoronary stents without the use of prolonged anticoagulation.

MATERIAL AND METHODS

Between Mar. 30, 1993, and Jun. 30, 1995, 889 patients with 1,194 coronary or vein graft lesions underwent implantation of one of six types of stents-Palmaz-Schatz, Gianturco-Roubin, Wiktor, Micro, Cordis, or Wallstent. The patients were classified into seven groups on the basis of the type of stent that was implanted, including one group with combined use of two or more types of stents. Among the 851 patients with successful stent delivery and without major complications, 801 received only antiplatelet therapy, and 50 received a standard anticoagulation regimen. One-month clinical followup data were obtained in all patients, and clinical events were investigated.

RESULTS

The mean number of stents was 1.8 per lesion and 2.4 per patient. Procedural success was achieved in 93% of the lesions. The clinical success rate at 1 month was 90%. Intravascular ultrasound assessment was performed in 90% of the lesions. The final minimal luminal cross-sectional area of the stent increased from 6.8 to 7.8 mm2 after intravascular ultrasound-guided optimization. Within 1 month, 16 stent thrombosis events (1.9%) occurred. No significant differences were noted in stent thrombosis rates among the various stent cohorts. Multivariate logistic regression analysis revealed that the final stent minimal luminal diameter measured by intravascular ultrasonography was the only variable associated with stent thrombosis.

CONCLUSION

This study showed that six different stents could possibly be inserted without subsequent anticoagulation if optimal stent expansion and total lesion coverage were achieved.

High pressure assisted coronary stent implantation accomplished without intravascular ultrasound guidance and subsequent anticoagulation

OBJECTIVES

The purpose of this study was to determine the efficacy of treatment with antiplatelet therapy and no anticoagulation after high pressure assisted coronary stent implantation performed without intravascular ultrasound (IVUS) guidance.

BACKGROUND

Previous studies have shown that during IVUS-guided Palmaz-Schatz coronary stenting, it is safe to withhold anticoagulation when stent expansion has been optimized by high pressure balloon dilation.

METHODS

Patients that had successful coronary stenting without IVUS guidance were treated with ticlopidine, 500 mg/day, and aspirin, 325 mg/day, for 1 month and then received only aspirin, 325 mg/day, indefinitely. Patients were not treated with warfarin (Coumadin) or heparin after successful stenting. Clinical and angiographic events were assessed at 1 month.

RESULTS

A total of 201 intracoronary stents were implanted in 127 patients with 137 lesions. The average number of stents per lesion was 1.4 +/- 0.8, and the average number of stents per patient was 1.6 +/- 1.1. Stent deployment was performed for elective indications in 79% of procedures and for emergency indications in 21%. There were four stent thrombosis events for a per patient event rate of 3.1% and a per lesion event rate of 2.9%.

CONCLUSIONS

After high pressure assisted stenting performed without IVUS guidance, there was an acceptable incidence of 3.1% of stent thrombosis with the combination of short-term ticlopidine and aspirin therapy and no anticoagulation. Although the study involved only 127 patients, the results support the relative safety of stenting without IVUS guidance and with antiplatelet therapy only in comparison to historical trials on stenting performed with postprocedure anticoagulation.

Coronary stenting in 1000 consecutive patients. Long-term clinical and angiographic results

Coronary stent implantation has become an accepted treatment for selected patients but the long-term outcome after stent implantation has not been investigated in a large unselected population. This study reports clinical and angiographic results after coronary stent implantation in a consecutive group of 1000 patients treated between November 1989 and June 1994. A total of 2012 stents were implanted in 1216 lesions. The anticoagulation regimen after successful stenting was abolished in the last 499 patients, treated with aspirin and ticlopidina. Complex lesions (type B2, type C lesions and chronic total occlusions) were less frequent in the group with anticoagulation (67%, 355/529 lesions) than in the group without anticoagulation (76%, 485/641; p < 0.01). Vessel size was also significantly smaller in the group with no anticoagulation (3.21 +/- 0.50 mm vs 2.89 +/- 0.70 mm; p < 0.001). Procedural success was achieved in 96% of cases. Major complications occurred in 49 pts, including death (1%), emergency bypass surgery (2.7%), and myocardial infarction (2.1%). Subacute stent thrombosis, observed in 2.6% of the patients treated with anticoagulation, decreased to 1% in the last 499 patients receiving only antiplatelet drugs after high pressure stent expansion controlled with intravascular ultrasound (p < 0.05). Angiographic follow-up was obtained at a mean interval of 6.6 +/- 3.0 months in 718 patients (75% of the eligible candidates). The global restenosis rate (greater than 50% diameter stenosis) was 22%, with no statistically significant difference in patients with and without anticoagulation after stenting. Clinical follow-up was available in 890 patients at a mean interval of 14 +/- 17 months. Late cardiac events occurred in 251 patients and included: 159 repeat coronary angioplasties for restenosis (20%), 114 coronary angioplasties for de novo lesions (10%), 33 elective by-pass surgery operations (3.7%) and 42 late deaths (4.7%). At the most recent follow-up there were 719 pts (81%) free of anginal symptoms, including patients having repeat angioplasty for restenosis or disease progression. Coronary stenting has a low incidence of procedural complications and high-pressure ultrasound guided implantation has drastically reduced the risk of subacute thrombosis. Repeat procedures due to restenosis remain the most important limitation of the technique and do not seem to be affected by evolving technique and operator experience.

Results of coronary stenting for restenosis

OBJECTIVES

This study attempted to analyze immediate and long-term angiographic and clinical results of coronary stent implantation for restenosis in a consecutive group of patients.

BACKGROUND

The rate of stent utilization in patients with coronary artery disease has increased exponentially in recent years. There are many unanswered questions about the use of stenting in patients with restenosis, particularly with respect to late clinical and angiographic results.

METHODS

A total of 159 stents were implanted in 128 consecutive patients with 139 lesions (mean 1.3 stents/patient). A technique of optimal stent expansion was used in all patients, and intravascular ultrasound guidance with no subsequent anticoagulation was performed in 41 patients.

RESULTS

Stent implantation was successful in 126 patients (98%). Four patients (3.1%) had complications (in two after successful stenting): death in one, emergency bypass surgery operation in two and subacute stent thrombosis in one. Stents were implanted with a final balloon size (mean +/- SD) of 3.5 +/- 0.5 mm and a mean maximal pressure of 11 +/- 4 atm (range 8 to 20). Angiographic restenosis occurred in 27 patients (25%). Regression analysis on clinical and angiographic variables for prediction of restenosis showed no statistical significance for any variable. Late events occurred in 23 patients (19%). The actuarial survival rate was 98% at 1 year and at 3 years, and the event-free survival rate including freedom from repeat angioplasty for restenosis was 95% and 76%, respectively.

CONCLUSIONS

The late angiographic outcome, restenosis rate and total clinical events are favorable for selected patients undergoing stent implantation for the indication of restenosis.

Somatic-cell selection is a major determinant of the blood-cell phenotype in heterozygotes for glucose-6-phosphate dehydrogenase mutations causing severe enzyme deficiency

X-chromosome inactivation in mammals is regarded as an essentially random process, but the resulting somatic-cell mosaicism creates the opportunity for cell selection. In most people with red-blood-cell glucose-6-phosphate dehydrogenase (G6PD) deficiency, the enzyme-deficient phenotype is only moderately expressed in nucleated cells. However, in a small subset of hemizygous males who suffer from chronic nonspherocytic hemolytic anemia, the underlying mutations (designated class I) cause more-severe G6PD deficiency, and this might provide an opportunity for selection in heterozygous females during development. In order to test this possibility we have analyzed four heterozygotes for class I G6PD mutations: two with G6PD Portici (1178G-->A) and two with G6PD Bari (1187C-->T). We found that in fractionated blood cell types (including erythroid, myeloid, and lymphoid cell lineages) there was a significant excess of G6PD-normal cells. The significant concordance that we have observed in the degree of imbalance in the different blood-cell lineages indicates that a selective mechanism is likely to operate at the level of pluripotent blood stem cells. Thus, it appears that severe G6PD deficiency affects adversely the proliferation or the survival of nucleated blood cells and that this phenotypic characteristic is critical during hematopoiesis.

High-level regulated expression of the human G6PD gene in transgenic mice

The glucose-6-phosphate dehydrogenase-encoding gene (G6PD) belongs to a group with constitutive expression in all tissues. The regulation of these housekeeping genes is poorly understood, as compared to what is known about many genes whose expression is restricted to a particular tissue or stage of development, and which are often regulated by locus control regions (LCR) able to act over wide distances. In order to identify sequences in human G6PD which are necessary for its expression, we have generated transgenic mice carrying a 20-kb G6PD construct, including only 2.5 kb of upstream and 2.0 kb of downstream flanking sequence. All mice which carried the transgene (TG) expressed it, and the levels of expression detected in a range of tissues from three independent lines of mice were comparable to that of the endogenous murine G6PD. The variation in enzyme activity from tissue to tissue was remarkably similar for both the TG and the endogenous gene, and was shown to be due in both cases to variations in the steady-state mRNA levels.

A new lease of life for an old enzyme

We review here some recent data about glucose-6-phosphate dehydrogenase (G6PD), the first and key regulatory enzyme of the pentose phosphate pathway. New evidence has been presented to suggest that malaria is a selective agent for G6PD deficiency, which is the most common enzymopathy in man, and that G6PD deficiency, generally considered to be a mild and benign condition, is significantly disadvantageous in certain environmental conditions. At the molecular level, the enzyme structure has recently been elucidated and mechanisms regulating G6PD gene expression have been determined. A G6PD knock-out mutation introduced in mouse cells makes them exquisitely sensitive to oxidative stress, indicating that this ubiquitous metabolic enzyme has a major role in the defence against oxidative stress, even in eukaryotic nucleated cells, which have several alternative routes for providing the same protection. Because of the high prevalence of G6PD deficiency in many populations, it is expected that these findings will prompt further studies to ascertain the putative role of G6PD deficiency in conditions such as carcinogenesis and ageing.

MRI study of a physiotherapeutic protocol in anterior disk displacement without reduction

Disk displacement of the temporomandibular joint (TMJ) without reduction has been considered a fundamental pathophysiologic abnormality of the joint. In this paper there are supportive clinical and MRI evidence of a successful repetitive manipulative technique for the treatment of acute and chronic locking. In 1500 treated cases, documented on videotape, only five cases required surgical intervention. The success of the therapy was confirmed by 13 MRI images of the TMJ of patients with acute and chronic locking before and after therapy. In all cases the anteriorly dislocated disk in closing and opening position was recaptured and repositioned in a normal position in the temporomandibular fossa. Three complete cases are reported with complete clinical and MRI documentation.

Successful closure of a coronary vessel rupture with a vein graft stent: case report

We report a successfully percutaneous closure of a brisk coronary artery rupture with a custom-made "vein graft stent," a Palmaz-Schatz stent covered with a vein graft. This method is an elegant and effective alternative to the traditional surgical approach and should be considered whenever technically and clinically feasible.

Acute recoil of Palmaz-Schatz stent: a rare cause of suboptimal stent implantation--report of two cases with intravascular ultrasound findings

It is generally believed that the Palmaz-Schatz stent maintains a strong radial force, preventing stent recoil. However, the capacity to prevent recoil is largely governed by the hardness or resistance of the lesion. We report two cases of "acute Palmaz-Schatz stent recoil," documented by intravascular ultrasound, and suggest a novel treatment of this unusual problem.