Incidence of infective endocarditis and its thromboembolic complications in a pediatric population over 30years

BACKGROUND

Pediatric infective endocarditis (IE) has been associated with high morbidity and mortality, mostly related to thromboembolic complications (TEC). The objective of our study was to describe the experience in children with IE and to review the changes over a thirty-year period, regarding origin of IE, incidence of vegetations, TEC and their respective morbidity and mortality rates.

METHODS

A retrospective chart review of children aged 0-18years with IE defined by the Duke Criteria and admitted to The Hospital for Sick Children, was conducted. Data were divided into three periods (P); P1 (1979-1988); P2 (1989-1998); and P3 (1999-2008).

RESULTS

The study included 113 patients, median age 7yrs.; females: 46 (41%), congenital heart defects 95 (84%), comparable in all periods. Overall, cardiac vegetations were found in 68/113 patients (60%); large vegetations (≥1cm) in 32 patients (28%). Fourty-five (45/133 [40%]) TEC were documented, 22 patients (20%) developed cerebrovascular events (CVE) and 23 patients (20%) had non-CVE. Patients diagnosed during P3 were older, had more vegetations (p<0.05), and a higher incidence of community acquired-IE (p<0.05). Overall, mortality was 15%, comparable in all periods. Significant risk factors for mortality were vegetations (HR 6.44; 95% CI: 2.07-20.01, p=0.002) and heart failure (HR 28.39; 95% CI: 10.49-76.85, p<0.001).

CONCLUSIONS

Over the study period, we report a growing incidence of community acquired pediatric IE in older children accompanied by an increasing rate of TEC. Heart failure and vegetations were associated with an increased mortality. These preliminary data need to be confirmed by prospective data.

Massive lindane overdose with toxicokinetics analysis

BACKGROUND

Lindane is a possible carcinogen with known teratogenicity and immunologic and neurotoxic properties. Despite reports of seizures, coma, and death associated with its use as well as banning of its environmental use by the Environmental Protection Agency (EPA), the US Food and Drug Administration (FDA) still allows treatment with lindane as a second-line scabicide and pediculicide. We present a case of a massive suicidal ingestion of lindane in which the patient survived the ingestion, though he did expire shortly thereafter from an unrelated cause pre-discharge.

METHODS

Pharmacokinetic analysis of serum lindane concentrations was performed with Phoenix® WinNONLIN®. The estimated distribution half-life for lindane was 10.3 h, and the terminal half-life was 162.9 h, much longer than the previously reported terminal half-life of 25-36 h. Because of this long half-life, repeated lindane exposures may lead to accumulation of lindane in the tissues.

RESULT

After overdose, toxicity may be delayed and full recovery may be prolonged.

Children after fontan have strength and body composition similar to healthy peers and can successfully participate in daily moderate-to-vigorous physical activity

The objective of this study was to evaluate the active lifestyle capacity (daily physical activity, strength, flexibility, body composition) of children after the Fontan procedure; hypothesized to be lower than healthy peers. Participants (n = 64, 25 females) were 9.0 ± 1.7 years of age (range 6.0-11.7 years). Fontan completion occurred at 3.3 ± 1.4 years of age (5.7 ± 2.0 years prior). Canadian Health Measures Survey protocols assessed aerobic endurance (paced walking up/down steps), strength (handgrip), flexibility (sit and reach), body composition (body mass index), and daily moderate-to-vigorous physical activity (7-day accelerometry). Difference scores compared participant data to published norms (t tests). Linear regression evaluated age/gender/demographic factor associations. Children after Fontan had strength scores similar (mean difference 1.1 kg) to their peers were less likely to be obese (mean difference of body mass index = 1.1 ± 2.5, p = 0.001) and performed 50 min of moderate-to-vigorous activity (MVPA) per day (12 ± 17 min/day below healthy peers, p < 0.001). Estimated peak endurance (61 % of expected) and flexibility (64 % of expected) were lower than peers (p < 0.001). Almost all (60/63) participants demonstrated the capacity to perform at least 20 min of MVPA per day. Difference from norms was smaller among children younger at Fontan completion (4 ± 2 min/year) and taking antithrombotic medication (7 ± 18 and 22 ± 17 min/day for taking/not taking, respectively). Children after Fontan demonstrate the capacity for the daily physical activity associated with optimal health. They have similar strength and good body composition. We recommend that children after Fontan be counselled that they can successfully participate in healthy, active lifestyles and physically active peer play.

Review of toxicity and trends in the use of tiagabine as reported to US poison centers from 2000 to 2012

BACKGROUND

Tiagabine is a novel antiepileptic that acts by increasing synaptic and extracellular gamma-aminobutyric acid concentrations. Information concerning overdose of tiagabine is limited. After introduction, an increasing number of off-label uses suggested that tiagabine use would increase. However in 2005 and 2008, warnings from the Food and Drug Administration (FDA) were issued on the risk of seizures in non-epileptic and increased suicide ideation. We evaluated the temporal trends associated with these two warnings as well as clinical outcomes from tiagabine overdose.

METHOD

A retrospective review of all single substance tiagabine exposures in National Poison Data System (NPDS) from 2000 to 2012.

RESULTS

A total of 2147 patients had ingested tiagabine, with a mean of 165 year(-1). This was disproportionally distributed, with a steep rise leading up to 2004 (max 559 year(-1)) and then a significant decline (p < 0.05) between 2005 and 2006. The number of cases reported to NPDS mirrored the sales of tiagabine. Clinical effects were predominantly neurological, with the most commonly reported effects being drowsiness (27%), agitation (19%), confusion (12%), seizures (11%), and tachycardia (10%). In all, 758 patients (35%) showed a major or moderate medical outcome, with no deaths reported. A disproportionate share of the major outcomes was in the suicide attempt group (73%). The majority of patients (75%) were treated in a health-care facility (HCF).

CONCLUSIONS

The HCF usage is likely due to high rate of symptomatic patients (59%) and the large proportion of suicide attempt cases. The frequency of tiagabine cases in NPDS mirrored pharmaceutical sales, with steep declines temporally related to the 2005 FDA warning.

Identification of N-Hydroxy-para-aminobenzoic acid in a cyanotic child after benzocaine exposure

CONTEXT

Methemoglobinemia (MetHb) after exposure to benzocaine (BZC) has been reported for more than 50 years, however the pathophysiologic mechanism has not been previously established. Direct administration of BZC to blood does not produce MetHb. After topical use, due to the lipophilicity and rapid acetylation in the tissue, little BZC reaches the liver for hepatic biotransformation. However, isolated human livers have been shown to produce MetHb forming N-hydroxyl metabolites from BZC. We report a case of BZC-induced MetHb with the first identification and quantification of the reactive metabolite responsible for the oxidative stress: N-Hydroxy-Para-amino benzoic acid (N-OH-PABA).

CASE DETAILS

An 8 year old male was admitted to a hospital for an appendectomy. Several applications of BZC spray were used during multiple attempts at nasogastric tube placement. In various attempts to achieve local anesthesia, benzocaine spray was used in both nares and through the mouth aimed at the posterior oropharynx. The patient subsequently became cyanotic with an initial MetHb level of 32.9 %. Methylene blue was administered and the patient promptly responded with resolution of cyanosis. Blood taken within 20 min of the initial symptoms contained benzocaine (5.2ug/mL), bupivacaine (740ng/mL), lidocaine (530ng/mL), acetaminophen (12ug/mL), midazolam (60ng/mL), PABA and N-OH-PABA (35ng/mL). Serum was analyzed using Liquid Chromatography- Quadrupole Time-of-Flight Mass Spectrometry. Mass spectrometry was done using an electrospray ionization source run in negative and positive polarities. A reference standard for N-OH-PABA was synthesized for confirmation and quantification.

DISCUSSION

The rare and idiopathic nature of methemoglobinemia after benzocaine use has made study of the pathophysiologic mechanism in humans difficult. Lack of understanding has brought calls for restriction of use of the widely used medication that may not be based on evidence. Our case presents several unique features: 1) benzocaine absorption after topical administration was documented with serum concentrations 2) confirmation of an in vivo formation of MetHb-forming n-hydroxyl-metabolite after benzocaine use and 3) the documentation of N-OH-PABA in humans within 20 min of MetHb post-benzocaine administration.

Termite fishing laterality in the Fongoli savanna chimpanzees (Pan troglodytes verus): further evidence of a left hand preference

Whether nonhuman primates show population-level handedness is a topic of much scientific debate. A previous study of handedness for termite fishing reported population-level left handedness in the chimpanzees from Gombe National Park, Tanzania. In the current study, we examined whether similar hand preferences were evident in a savanna-dwelling chimpanzee population with regards to termite fishing. Hand preference data were collected for 27 chimpanzees from February 2007 through July 2008 and November 2011 through January 2012 in southeastern Senegal. Overall, the Fongoli chimpanzees demonstrate a trend toward population-level handedness, though the results did not reach conventional levels of statistical significance likely due to the limited sample size. Fongoli chimpanzees showed the same pattern of left hand preference as reported at Gombe and the two populations did not differ significantly. When the data were combined across all studies, wild chimpanzees showed a population-level left hand preference for termite fishing.

Early determinants of atherosclerosis in paediatric systemic lupus erythematosus

OBJECTIVES

To assess traditional and non-traditional cardiovascular risk factors and to determine the prevalence and correlates of early vascular markers of atherosclerosis in paediatric systemic lupus erythematosus (pSLE).

METHODS

Fifty-four adolescents with pSLE had cardiovascular risk factor assessment, disease activity and vascular testing including carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), arterial stiffness measures, and myocardial perfusion studies.

RESULTS

The traditional risk factors of hypertension, elevated triglycerides, apolipoprotein B, haemoglobin A1c and insulin levels and non-traditional risk factors of elevated homocysteine and fibrinogen were present (all p<0.001). Some arterial stiffness measures, central pulse wave velocity and characteristic impedance were elevated (p<0.001), but CIMT, FMD and myocardial perfusion were normal. Cumulative prednisone dose correlated with total cholesterol (r=0.5790, p<0.001) and elevated LDL-C (r=0.4488, p=0.0012). Hydroxychloroquine treatment correlated negatively with total cholesterol (r=-0.4867, p=0.0002), LDL-C (r=-0.4805, p=0.0002) and apolipoprotein B (r=-0.4443, p=0.0011). In multivariate analysis LDL-C correlated with cumulative prednisone dose and negatively with hydroxychloroquine treatment (R2=0.40, p<0.001).

CONCLUSIONS

An increased burden of traditional and non-traditional risk factors and early evidence of insulin resistance and increased central arterial stiffness were present in paediatric SLE. Disease-specific and therapy-related factors are likely modifying these cardiovascular risk profiles warranting prospective longitudinal studies.

Handedness for tool use in captive chimpanzees (Pan troglodytes): Sex differences, performance, heritability and comparison to the wild

There is continued debate over the factors influencing handedness in captive and wild primates, notably chimpanzees. Previous studies in wild chimpanzees have revealed population-level left handedness for termite fishing. Here we examined hand preferences and performance on a tool use task designed to simulate termite fishing in a sample of 190 captive chimpanzees to evaluate whether patterns of hand use in captive chimpanzees differed from those observed for wild apes. No population-level handedness was found for this task; however, significant sex differences in preference and performance were found, with males showing greater left handedness and poorer performance compared to females. We also found that the hand preferences of offspring were significantly positively correlated with the hand preferences of their mothers. Lastly, older females performed more slowly on the task compared to younger individuals. The overall results neither confirm nor reject previous hypotheses claiming that raising chimpanzees in captivity induces right-handedness, but rather suggest that other factors may account for differences in hand preferences for tool use seen in wild and captive chimpanzees.

E2F1 suppresses skin carcinogenesis via the ARF-p53 pathway

The E2F1 transcription factor, which is deregulated in most human cancers by mutations in the p16-cyclin D-Rb pathway, has both oncogenic and tumor-suppressive properties. This is dramatically illustrated by the phenotype of an E2F1 transgenic mouse model that spontaneously develops tumors in the skin and other epithelial tissues but is resistant to papilloma formation when subjected to a two-stage carcinogenesis protocol. Here, this E2F1 transgenic model was used to further explore the tumor-suppressive property of E2F1. Transgenic expression of E2F1 was found to inhibit ras-driven skin carcinogenesis at the promotion stage independent of the type of promoting agent used. E2F1 transgenic epidermis displayed increased expression of p19(ARF), p53, and p21(Cip1). Inactivation of either p53 or Arf in E2F1 transgenic mice restored sensitivity to two-stage skin carcinogenesis. While Arf inactivation impaired tumor suppression and p21 induction by E2F1, it did not reduce the level of apoptosis observed in E2F1 transgenic mice. Based on these findings, we propose that E2F1 suppresses ras-driven skin carcinogenesis through a nonapoptotic mechanism involving ARF and p53.

Total cavopulmonary connections in children with a previous Norwood procedure

BACKGROUND

Outcomes of the Fontan operation in children initially palliated with the modified Norwood procedure are incompletely defined.

METHODS

From August 1993 to January 2000, 45 patients (mean age 2.6 +/- 1.1 years, weight 12.7 +/- 2.8 kg) who were palliated with staged Norwood procedures (hypoplastic left heart syndrome, n = 32; nonhypoplastic left heart syndrome, n = 13) underwent a modified Fontan operation. Preoperative features included moderate/severe atrioventricular valve regurgitation (n = 5, 11%), reduced ventricular function on echocardiography in 11 patients, McGoon index 1.56 +/- 0.38, and pulmonary artery distortion in 18 patients (40%).

RESULTS

A lateral tunnel (n = 16) or an extracardiac conduit (n = 29) connection with fenestration in 38 patients (84%) was used. Concomitant procedures included pulmonary artery reconstruction (n = 24, 53%), atrioventricular valve repair (n = 4, 9%) or replacement (n = 1). Before Fontan, 12 patients (27%) had an intervention to address neoaortic obstruction, and 7 patients required balloon dilation/stenting of the left (n = 5) or right pulmonary artery (n = 5). Intraoperatively, left (n = 5) or right pulmonary artery (n = 1) stenting was performed in 5 patients (11%). On follow-up, 8 patients required additional interventional procedures to address left pulmonary artery narrowing (n = 5), or venous (n = 5) or arteriopulmonary collaterals (n = 1). Perioperative mortality was 4.4% (n = 2). There were 2 late deaths at a mean follow-up of 39 +/- 20 months.

CONCLUSIONS

In relatively high-risk patients, midterm results of the Fontan operation for children initially palliated with the Norwood procedure were good. Combined interventional-surgical treatment algorithms can lead to improved outcomes.

A comparison of hydroxylapatite coated implant retained fixed and removable mandibular prostheses over 4 to 6 years

In a 6-year prospective clinical study, 181 hydroxylapatite coated endosseous dental implants were placed into the anterior mandible of 48 patients. Twenty-one patients were treated with fixed prostheses and 27 patients with an overdenture. When the implants were exposed all 181 had integrated. To date, there is 100% survival of all implants and they all retain a functioning prostheses. The initial results were very promising, in both groups the interval success was over 95% in the first 4 years of the study. However, by year 6, the interval success rates had fallen to 83% for both the fixed and removable groups. This study also compares the construction and maintenance complications for the two types of restorations. The clinical time taken, after implant exposure, to construct the prostheses was similar whether the fixed (mean of 8 visits) or removable option (mean of 7 visits) was chosen. However, the removable restoration cost less than half the price of the fixed when both technical time and implant component costs were evaluated. Maintenance for both groups was higher than expected, but patients required more appointments in the removable group both in the first year and beyond. Regarding the prostheses itself, the incidence of remakes, relines and general adjustments was higher in the removable group. This study has shown that the overdenture offers an effective and initially a more economical alternative to the fixed prostheses, in the treatment of the edentulous mandible. However, long-term maintenance of such a prosthesis can be significant.

Case report: the transmandibular implant system

This series of case reports outlines the use of the transmandibular implant system to rehabilitate 10 patients with severely resorbed mandibles. The implants were placed according to manufacturers' guidelines with the patient under a general anaesthetic and reviewed bi-annually thereafter. Three patients experienced problems: in two of these this involved the loss of integration of the distal posts, in the other patient the transmandibular implant was removed in its entirety. Distal locking screws became loose shortly after placement in three patients. Prosthetic complications included difficulty in obtaining passive fit of the superstructure in 7 patients and a high long-term maintenance commitment.

Surgical harvesting of bone graft from the ilium: point of view

Autologous bone harvested from the ilium is commonly used as a grafting material in surgical reconstructive and arthrodesis procedures to ensure a satisfactory postoperative outcome. However, operative removal of bone from the iliac crest requires an additional surgical procedure with a distinct set of postoperative complications. We provide a comprehensive literature synthesis of the incidence and severity of complications reported to be associated with this commonly practiced procedure. Most severe complications are rare, but chronic pain at the donor site exceeding three months in duration occurs frequently and can be particularly bothersome to patients. Alternative grafting materials that are safe and effective are sorely needed.

Augmenting local bone with Grafton demineralized bone matrix for posterolateral lumbar spine fusion: avoiding second site autologous bone harvest

Mineralization and integrity of the bone graft mass were evaluated among patients having posterolateral fusion. Grafting consisted of a composite of Grafton and "local" autologous bone (n=56) or iliac crest autograft alone (n=52). Mineralization was rated radiographically at baseline and at 3, 6, 12, and 24 months. Integrity was judged as fused or not fused. Mineralization ratings did not differ significantly between groups at any postoperative interval (P values of .25-1.00). The percentage of patients fused was similar in both groups (60% and 56% for Grafton and controls, respectively; P=.83). Fifteen control patients reported donor site pain. These findings warrant further evaluation of this composite.

E2F4 and E2F1 have similar proliferative properties but different apoptotic and oncogenic properties in vivo

Loss of retinoblastoma (Rb) tumor suppressor function, as occurs in many cancers, leads to uncontrolled proliferation, an increased propensity to undergo apoptosis, and tumorigenesis. Rb negatively regulates multiple E2F transcription factors, but the role of the different E2F family members in manifesting the cellular response to Rb inactivation is unclear. To study the effect of deregulated E2F4 activity on cell growth control and tumorigenesis, transgenic mouse lines expressing the E2F4 gene under the control of a keratin 5 (K5) promoter were developed, and their phenotypes were compared to those of previously generated K5 E2F1 transgenic mice. In contrast to what has been observed in vitro, ectopically expressed E2F4 was found to localize to the nucleus and induce proliferation to an extent similar to that induced by E2F1 in transgenic tissue. Unlike E2F1, E2F4 does not induce apoptosis, and this correlates with the differential abilities of these two E2F species to stimulate p19(ARF) expression in vivo. To examine the role of E2F4 in tumor development, the mouse skin two-stage carcinogenesis model was utilized. Unlike E2F1 transgenic mice, E2F4 transgenic mice developed skin tumors with a decreased latency and increased incidence compared to those characteristics in wild-type controls. These findings demonstrate that while the effects of E2F1 and E2F4 on cell proliferation in vivo are similar, their apoptotic and oncogenic properties are quite different.

Isolated origin of the left subclavian artery from the left pulmonary artery

We describe two children with isolated origin of the left subclavian artery from the left pulmonary artery detected by echocardiography during the assessment of their congenital cardiac malformations. Both patients demonstrated pre-operative evidence of subclavian steal. This entity results from persistence of the dorsal segment of the sixth left arch, with regression of the left fourth arch and interruption of the left dorsal arch distal to the origin of the seventh left intersegmental artery. The significance of this finding relates to the potential for pulmonary overcirculation, which could have significant post-operative ramifications if not detected prior to surgical repair of an associated cardiac malformation. This entity differs from cases with a right aortic arch and aberrant left subclavian artery which has the potential to form a vascular ring, unlike cases with isolated origin of the left subclavian artery from the pulmonary artery that do not cause compression of the airway.

The evolution of ductus arteriosus treatment

The treatment of patent ductus arteriosus (PDA) has evolved over the years. We reviewed 231 non-premature children (group 1) undergoing surgical closure of a PDA between January 1985 and December 1997, and 30 children (group 2) undergoing transcatheter closure from May 1995 to December 1998. The median age and weight at operation in group 1 were 13 months (range, 0.5-174 months) and 9.5 kg (range, 1.9-49.7 kg), respectively. There was one intra-operative death (0.4%) secondary to hemorrhage. Immediate extubation was performed in 208 patients (90%). Intra-operative chest tube use decreased from 73.3% to 10% between the 1985-88 and 1996-97 periods (P < 0.001). Postoperative pneumothoraces occurred in 33/131 (25%) patients with only one patient (0.7%) requiring drainage. Eleven patients had complications including wound infection in four, vocal cord paralysis in three, and left pulmonary artery stenosis in one. The median length of stay (LOS) was 5 days (range, 2-43 days). Follow-up echocardiogram was performed in 146/230 patients (63%) and revealed a residual PDA in six (4%); two being re-ligated, two remaining clinically insignificant, and two spontaneously resolved at 7 and 28 months follow-up. The remaining 84 patients had no clinical signs of a residual PDA. In group 2, where a transcatheter coil occlusion technique was used, the median age and weight at procedure were 31 months (range, 9-320 months) and 14.9 kg (range, 9-69.7 kg), respectively. Vascular complications occurred in four patients (13.3%). One patient developed hemolysis and hemoglobinuria requiring hospital admission. Four patients required a second intervention. At the most recent echocardiographic assessment, four patients (13.3%) had a residual PDA.

Total head excursion and resting head posture: normal and patient comparisons

OBJECTIVE

To determine whether significant differences existed between normal and patient groups on three postural measurements: anterior-posterior total head excursion (THE), resting head posture in sitting (RHPsit), and resting head posture in standing (RHPstd).

SUBJECTS

Forty-two healthy subjects, 13 men and 29 women between the ages of 20 and 60 years, were matched to 42 patients according to gender and age.

DESIGN

Measurements of THE, RHPsit, and RHPstd were taken for each subject. Patients were measured during their initial evaluation and had neck pain as a primary or secondary complaint.

RESULTS

A two-way multivariate analysis of variance followed by two-way analyses of variance showed that normal subjects had a significantly (p<.05) greater THE than did the patients and that men (patients and controls) scored significantly higher (p<.05) than women (patients and controls) on both THE and RHPstd.

CONCLUSION

Clinical assessment of patients with cervical pain should focus on cervical mobility rather than resting head posture. Head/neck posture is different for males and females and they should not be judged by the same standard.

E2F1 has both oncogenic and tumor-suppressive properties in a transgenic model

Using a transgenic mouse model expressing the E2F1 gene under the control of a keratin 5 (K5) promoter, we previously demonstrated that increased E2F1 activity can promote tumorigenesis by cooperating with either a v-Ha-ras transgene to induce benign skin papillomas or p53 deficiency to induce spontaneous skin carcinomas. We now report that as K5 E2F1 transgenic mice age, they are predisposed to develop spontaneous tumors in a variety of K5-expressing tissues, including the skin, vagina, forestomach, and odontogenic epithelium. On the other hand, K5 E2F1 transgenic mice are found to be resistant to skin tumor development following a two-stage carcinogenesis protocol. Additional experiments suggest that this tumor-suppressive effect of E2F1 occurs at the promotion stage and may involve the induction of apoptosis. These findings demonstrate that increased E2F1 activity can either promote or inhibit tumorigenesis, dependent upon the experimental context.

A 3 to 4 year study of single tooth hydroxylapatite coated endosseous dental implants

OBJECTIVE

To evaluate the clinical effectiveness, common complications and maintenance associated with hydroxylapatite (HA) coated cylindrical implants when used to support single crowns.

DESIGN

A prospective medium term clinical study of the Calcitek HA-coated implant.

SETTING

Implant placement, crown fabrication and follow-up procedures were carried out at the Leeds Dental Institute, between 1990 and 1998.

SUBJECTS AND METHOD

26 patients (33 implants) participated in the trial. They were referred from general dental practitioners because of their suitability for single tooth implant placement.

MAIN OUTCOME MEASURES

The implants were assessed using recognised clinical review procedures e.g. radiographs and soft tissue assessments.

RESULTS

At exposure there was 100% implant integration. The cumulative survival rate over 4 years was 100%. In five implants there was cervical bone loss of more than 4 mm and these were classified as failing. This gave an overall cumulative success rate of 58% by year 4.

CONCLUSION

The Calcitek HA-coated single tooth implant shows exceptionally high initial integration however, the longer term results suggest that the cervical bone level adjacent to the implant failed to establish a steady state. Doubts remain regarding the long-term prognosis of these cylindrical HA-coated implants.

Clinical utility of demineralized bone matrix for osseous defects, arthrodesis, and reconstruction: impact of processing techniques and study methodology

The findings of studies on DBM in the surgical management of osseous defects, arthrodeses, and reconstructive procedures have been promising. In general, DBM grafts have supported healing in a timely fashion without complication and with a diminished need to harvest bone from a secondary operative site. Nonetheless, controlled prospective trials are needed to confirm the comparative effectiveness of DBM and to quantitate the benefits of avoiding secondary site autologous bone harvesting. Notwithstanding the known deleterious effects of certain processing steps, current commercial demineralization processes vary widely and use ancillary procedures aimed at attenuating potential residual antigens and pathogens. While some of these procedures may improve or facilitate graft performance (eg, lipid and lipoprotein removal with detergents), others may be deleterious (eg, sterilization with radiation or ethylene oxide) (Table 1). Therefore, it is important that DBM be processed using methods that consistently establish conditions known to preserve DBM's documented osteoinductive potential and that authors appropriately identify processing methods known to have effects on graft performance.

Intermediate follow-up of right ventricular outflow tract reconstruction with allograft conduits

BACKGROUND

Allograft conduits are among many varieties of material used for right ventricular outflow tract reconstruction. They invariably need to be replaced due to growth of the patient or conduit failure.

METHODS

From June 1984 to June 1996, a total of 76 patients underwent reconstruction of the right ventricular outflow tract with an allograft conduit: 51 aortic and 25 pulmonary. The median age, weight and conduit size at surgery were 37 months (range, 0.2 to 228 months), 12.4 kg (range, 2.9 to 61.4 kg), and 17 mm (range, 8 to 26 mm), respectively.

RESULTS

The hospital mortality was 5.3% (4 of 76 patients) and 2 patients died at 9 and 78 months follow-up. The median follow-up was 61 months (range, 2 to 132 months). Reoperation was necessary in 22 patients (28.9%) at a median interval of 50.5 months (range, 3 to 109 months) and the median conduit size was 21 mm (range, 12 to 23 months). There was no mortality. Freedom from reoperation at 64 months was 49.5% for conduits 15 mm and smaller, and 73.3% for conduits 16 mm and larger. Analysis by age shows freedom from reoperation at 64 months of 49.4% and 74.5% for patients younger than and older than 2 years, respectively. At 54 months there was no statistical difference in freedom from reoperation between pulmonary and aortic allografts.

CONCLUSION

Right ventricular outflow tract reconstruction with allograft conduits results in a high reoperation rate at 4 years but provides significantly longer freedom from reoperation with conduits larger than 15 mm or in patients over 24 months of age.

Risks of repeat sternotomy in pediatric cardiac operations

BACKGROUND

Repeat sternotomy has been associated with increased perioperative risks.

METHODS

We reviewed 165 patients undergoing 192 repeat sternotomies between January 1985 and January 1997 (group 1) and a control group of 184 patients (group 2). The operations in group 1 were valve procedures in 94 patients, Fontan procedure in 46, ventricular septal defect closure in 10, pulmonary arterioplasty in 17, and others in 25; in group 2 ventricular or atrial septal defect closure in 120 patients, tetralogy of Fallot repair in 26, valve procedures in 16, bidirectional Glenn anastomosis in 7, repair of transposition of the great arteries in 7, pulmonary arterioplasty in 4, and others in 4.

RESULTS

The hospital mortality was 2.6% in group 1 and 3.8% in group 2. Cardiac laceration occurred in 10 of 192 patients (5.2%), requiring emergent femorofemoral bypass in 6 patients. Two patients sustained an air embolism that was successfully treated with a hyperbaric chamber. Median total blood loss and requirements were not significantly different between the two groups. The length of stay in the intensive care unit and in the hospital were 4 days (range, 1 to 80 days) and 11 days (range, 1 to 135 days) in group 1, and 2 days (range, 1 to 87 days) and 7 days (range, 1 to 131 days) in group 2 (p < 0.02 and p < 0.002, respectively). The rate of complications was not significantly different in group 1 versus group 2. Overall survival was 97% (group 1) and 95% (group 2) at 120 months' follow-up (not significant).

CONCLUSIONS

With careful surgical technique and judicious use of femorofemoral bypass, the risk of repeat sternotomy is minimized.

A 3- to 6-year study of overdentures supported by hydroxyapatite-coated endosseous dental implants

PURPOSE

The purpose of this study was to evaluate the clinical effectiveness of hydroxyapatite-coated cylindrical implants to support overdentures. These implants were placed between 1990 and 1994 and have been followed up over a period of 3 to 6 years.

MATERIALS AND METHODS

One hundred thirty-nine Calcitek dental implants were placed in 43 patients to support 14 maxillary and 30 mandibular overdentures. Standardized clinical review procedures were used.

RESULTS

At exposure all the implants were found to be osseointegrated. To date only 7 implants (5%) have completely failed and two associated overdentures (5%) have been lost. The cumulative survival rate of all implants over 6 years was 92%. However, if failure is defined by the loss of more than 4 mm of cervical bone, 33 implants could be classified as being in the process of failing. Using these figures, interval success rates as low as 82% were found by year 6, and the cumulative success rate would fall to 39%. Maxillary survival and success rates were significantly lower than mandibular rates, at 38% and 10%, respectively, by year 5.

CONCLUSION

Failure rates were higher in the maxillary arch, in poor quality bone, in smokers, and where implants were opposed by a natural dentition or an implant-supported prosthesis. The results suggest that the cervical bone level adjacent to the Calcitek cylindrical hydroxyapatite-coated implant failed to establish a steady state, particularly in the maxillary arch. Doubts remain regarding the long-term prognosis of these cylindrical implants.

Is surgical closure of patent ductus arteriosus a safe procedure in premature infants?

Despite indomethacin therapy, many premature infants require surgical closure of their patent ductus arteriosus (PDA). Between January 1985 and December 1997, 176 premature infants underwent surgical closure of PDA by vascular clip after failure of medical treatment. The median gestational age and birth weight were 26 weeks (range 23-36 weeks) and 847.5 g (range 400-2300 g), respectively. The median age at diagnosis and at surgery was 4 days (range, 1-37) and 21 days (range, 4-60) respectively. The median weight at surgery was 982.5 g (range 475-2740 g). Of these infants, 168 (95%) were intubated prior to surgery and the median time to extubation was 21 days (range 1-273 days). There were no operative deaths but 11 infants (6.4%) died from complications of prematurity (sepsis, bronchopulmonary dysplasia and pulmonary hemorrhage). The frequency of chest tube insertion at surgery decreased from 41.7% to 10% between the 1985-88 and 1996-97 periods (P<0.01). Three infants (1.7%) developed vocal cord paralysis directly related to the position of the vascular clip. Echocardiography confirmed PDA closure in 43 infants (24.4%) while the remaining 133 had no clinical signs of PDA. Surgical closure of PDA by vascular clip carries a very low morbidity in premature infants.

Pediatric cardiac surgery in the 1990s

Future developments in the repair of these complex anomalies will rely heavily on a complete understanding of present results, which can be achieved only with attention to detail and rigorous standards. Results must be continually updated and management changes carefully planned and then critically examined for significant differences. Thus, the day-to-day care of patients with congenital heart disease must withstand careful scrutiny, both for consistency and for end results.

Relatively low doses of cisapride in the treatment of nausea in patients treated with venlafaxine for treatment-refractory depression

Low doses of cisapride (5-10 mg twice daily) produced relatively rapid relief from nausea elicited by venlafaxine in six patients with treatment-refractory recurrent major depression. This further suggests that the nausea associated with serotonergic reuptake inhibition may be a result of 5-hydroxytryptamine (5-HT3) agonist action. No adverse cardiac experiences were encountered in spite of the potential interaction of cisapride with selective serotonin reuptake inhibitors at the cytochrome P4503A4 enzyme system.

Replantation of avulsed permanent teeth with avital periodontal ligaments: case report

Five maxillary anterior teeth lost during a grand mal epileptic seizure, were replanted using the technique recently described by Andreasen (1), after an extra-alveolar period of more than 72 h. The teeth were replanted surgically, 10 days after being avulsed, after they had been immersed in a 2.4% sodium fluoride solution and root filled with gutta-percha. Ankylosis was evident 3 months post-operatively. After 24 months there was evidence of considerable replacement resorption on the lateral incisors with little evidence of resorption on the other replanted teeth. Even though the long term prognosis is uncertain, this technique has an advantage of seeing the patient through the period of growth as well as maintaining the height of alveolar bone making possible the provision of an aesthetically acceptable prosthesis at a later age.

Clinical implications of depression in rheumatoid arthritis

The clinical implications of depression in the context of rheumatoid arthritis are described. An overview of the diagnostic criteria for depression is provided, with specific focus on major depression and the associated subtypes. The neurobiological literature on major depression is briefly reviewed and the implications of the depression literature for the care of persons with rheumatoid arthritis are discussed.

Achalasia mistakenly diagnosed as eating disorder and prompting prolonged psychiatric hospitalization

We have reported a rather extreme instance in which achalasia was misdiagnosed as a primary eating disorder. Our patient spent 2 months in a psychiatric institution before the correct diagnosis was made. Misdiagnosis in this case could have been avoided (1) if the symptoms of dysphagia had been elicited as part of her history, (2) if it had been recognized that the vomiting (her dominant symptom) was involuntary and not self-induced, (3) if the absence of disturbed body image had been appreciated, or (4) if it had been recognized that she did not meet accepted criteria for anorexia nervosa or bulimia. Our case and others like it in the literature also illustrate that achalasia frequently remains an elusive diagnosis.

Panic disorder in cardiology patients: a review of the Missouri Panic/Cardiology Project

This paper reviews current evidence from several cardiology populations that suggests that panic disorder is prevalent and underdiagnosed. Cardiology patients with atypical angina, and no heart disease have a high likelihood of having panic disorder, as suggested by studies of two separate cardiology populations. That they resemble psychiatric populations with panic is suggested by their positive response to alprazolam. A panic disorder subtype, called non-fear panic disorder also appeared in about one-third of these cardiology panic patients. These patients have most of the panic symptoms but do not report fear during their episodes.

Assessment of total head excursion and resting head posture

Clinicians typically evaluate head posture and cervical range of motion in both standing and sitting positions. There are currently few quantitative data available regarding resting head posture (RHP) or total head excursion (THE), a retraction-protraction gliding range of head motion in the sagittal plane, and where the RHP lies within THE. The purposes of this study were to describe quick and simple methods to determine quantitative measurements of THE, RHP while sitting, and RHP while standing, to provide preliminary data on these postural measurements for men and women in four age categories; and to determine the effects of gender and age on these measurements. Subjects included 218 able-bodied adults. Measurements of THE, RHP while sitting, and RHP while standing were taken. A two-way multivariate analysis of variance followed by two-way analyses of variance showed only the main effect of gender to be significant (p less than .05) for each of the dependent measurements. Across the age groups, men had a greater excursion distance from retraction to protraction than women. Within THE, women held their heads more forward than men. Men held their heads farther from the vertical than women while standing. These results indicate that normal head and neck posture is different for men and women and should not be judged by the same standard. The methods used in this study are clinically advantageous in that they produce objective, quantitative measurements of THE and RHP that may be obtained quickly and with minimal equipment.

Mitral valve prolapse, panic disorder, and chest pain

Mitral valve prolapse is a common cardiac disorder that can readily be diagnosed by characteristic auscultatory and echocardiographic criteria. Although many diseases have been associated with mitral valve prolapse, most affected individuals have the primary form of the disorder. Mitral valve prolapse is an inherited condition commonly associated with myxomatous degeneration of the mitral valve and its support structures. Complications of mitral valve prolapse, including cardiac arrhythmias, sudden death, infective endocarditis, severe mitral regurgitation (with or without chordae tendineae rupture), and cerebral ischemic events, occur infrequently considering the wide prevalence of the disorder. Panic disorder is a specific type of anxiety disorder characterized by at least three panic attacks within a 3-week period or one panic attack followed by fear of subsequent panic attacks for at least 1 month. It too is a common condition with a prevalence and age and gender distribution similar to that of mitral valve prolapse. Panic disorder and mitral valve prolapse share many nonspecific symptoms, including chest pain or discomfort, palpitations, dyspnea, effort intolerance, and pre-syncope. Chest pain is the symptom in both conditions that most commonly brings the patient to medical attention. The clinical description of chest pain in patients with mitral valve prolapse is highly variable, possibly reflecting multiple etiologies. Chest pain in panic disorder is usually characterized as atypical angina pectoris and as such bears resemblance to the chest pain commonly described by patients with mitral valve prolapse. Multiple investigative attempts to elucidate the mechanism of chest pain in both conditions have failed to identify a unifying cause. Review of the literature leaves little doubt that mitral valve prolapse and panic disorder frequently co-occur. Given the similarities in their symptomatology, a high rate of co-occurrence is, in fact, entirely predictable. There is, however, no convincing evidence of a cause-effect relationship between the two disorders, nor has a single pathophysiologic or biochemical mechanism been identified that unites these two common conditions. Until specific biologic markers for these disorders are identified, it may be impossible to do so. The lack of a proven cause-and-effect relationship between mitral valve prolapse and panic disorder and the absence of a unifying mechanism do not diminish the clinical significance of the high rate of co-occurrence between the two conditions. Primary care physicians and cardiologists frequently encounter patients with mitral valve prolapse and nonspecific symptoms with no discernible objective cause who fail to respond to beta-blockade. Panic disorder should be considered as a possible explanation for symptoms in such patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Validating studies for panic disorder in patients with angiographically normal coronary arteries

This article describes validating studies for diagnosing panic disorder in some patients with angiographically normal coronary arteries (NCA) and chest pain. Psychiatric interviews of 94 such patients showed that 34% met the diagnostic criteria for panic disorder. Further studies showed that NCA patients with panic disorder were more disabled at 3.5-year follow-up, had more relatives with panic disorder, were more likely to suffer from major depression, and were more likely to respond to 35% CO2 challenge with panic symptoms. Because panic disorder is highly disabling but responds well to psychological and pharmacologic treatments, screening NCA patients in the cardiology population for this disorder is recommended.

The use of computed tomography in the management of facial trauma by British oral and maxillofacial surgeons

A survey of 184 British oral and maxillofacial surgeons on their use of computed tomography (CT) in the management of craniofacial trauma showed that the majority of the 116 surgeons who replied used this form of imaging for frontal, nasoethmoidal, and orbital fractures. Only 6% of respondents reported no advantage in CT imaging over plain radiography. The access to CT scanners and the value of the reports in the management of patients was rated as satisfactory by 75% of respondents, and a similar percentage reported that CT service was becoming increasingly available to their units.

Nonfearful panic disorder in neurology patients validated by lactate challenge

OBJECTIVE

Nonfearful panic disorder meets the DSM-III-R criteria for panic disorder but is not associated with subjective fear and anxiety. The authors determined its prevalence in a group of neurology patients and assessed its diagnostic validity as a panic disorder subtype by evaluating the response of the patients with nonfearful panic disorder to sodium lactate and antipanic pharmacotherapy.

METHOD

The subjects were all neurology patients referred over 1 year to a university hospital's psychiatric consultation service because of negative medical workups for their symptoms (N = 48). Patients who met the DSM-III-R criteria for panic disorder but did not report subjective anxiety or fear during panic episodes were diagnosed as having nonfearful panic disorder. Afterward, each of those patients received a sodium lactate infusion and, 5 hours later, a sodium chloride infusion. They were then treated with antipanic medication and followed for at least 6 months.

RESULTS

Of the 48 neurology patients referred for psychiatric evaluation, 11 (23%) met the criteria for panic disorder, and all 11 met the criteria for nonfearful panic disorder. All 11 responded positively to lactate but not to placebo, and they each experienced an at least 75% reduction in symptoms during the 6-month follow-up period. Detailed case reports of three of these patients are presented.

CONCLUSIONS

These findings support the construct and predictive diagnostic validity of nonfearful panic disorder as a subtype of panic disorder and suggest that a lack of attention to this group leads to both the underestimation of the prevalence of panic disorder and to the withholding of potentially successful treatments for this group.

Computed tomography in the diagnosis of maxillofacial trauma

A study of 34 patients who were investigated for maxillofacial trauma using high resolution computed tomography (CT) scanning is presented. The areas where this increasingly available technique offers more accurate information than conventional plain radiographs are discussed.

Thin section computed tomography in the evaluation of naso-ethmoidal trauma

We reviewed the computed tomography (CT) appearances, plain film radiographs and clinical findings of 17 patients who suffered fractures of the naso-ethmoidal complex. Six patients (35%) with diplopia were noted on CT to have lateral displacement of medial orbital wall fragments into the orbit (medial wall 'blow-in' fractures) leading to displacement of the globe or extra-ocular muscles. Medial displacement of ethmoid bone fragments (medial wall 'blow-out' fractures) with medial rectus entrapment was noted in a further two cases (11%) also. Multiple associated facial fractures were seen in all but one case with CT evidence of frontal bone fracture and intracranial injury in 12 (70%) patients. CT was judged to add valuable information to clinical findings and plain film radiography and was especially helpful where marked soft tissue swelling precluded detailed physical examination of the naso-orbital region. The CT features of naso-ethmoidal trauma are illustrated and discussed and the advantages of CT in the pre-operative evaluation of such injuries are emphasised.

Retrograde root filling using antibiotic-containing, radiopaque, bone cement

An investigation is reported on the in-vitro behaviour, characteristics and properties of three gentamicin-containing radiopaque bone cements that are considered to be promising retrograde root-filling materials. Three commercially available cements, CMW-1G, CMW-3G and Palacos R with gentamicin were studied with regard to bacteriocidal properties, tissue compatibility in cell culture, and ability to seal tooth cavities as evidenced by dye diffusion. Results were compared and contrasted with those obtained with an amalgam. The antibiotic-containing cements investigated are considered to have some distinct advantages over amalgam when used as retrograde root-filling materials in vitro. Amalgam was found to have poor bacteriocidal properties and poor tissue compatibility but slightly better apical sealing abilities than the cements. No apparent drawbacks were found with the cements.

Cyclic AMP-resistant mutants of S49 mouse lymphoma cells hemizygous for expression of regulatory subunit of type I cyclic AMP-dependent protein kinase

For use in studies of the functional organization of regulatory (R) subunit of type I cAMP-dependent protein kinase, 84 independent cyclic AMP-resistant mutants were isolated from sublines of S49 mouse lymphoma cells that are hemizygous for expression of the R subunit. Mutants were characterized by two-dimensional gel analysis of the R subunits, assays of kinase activation, and assays of cAMP-binding. All but eight of the mutants had kinases with increased apparent Kas for cAMP-dependent activation, and studies with site-selective cAMP analogs revealed considerable phenotypic diversity among these mutants. Forty-nine of the mutants had "charge-shift" lesions that mapped to regions of the R subunit polypeptide implicated in cAMP-binding. Twenty-five of the "charge-shift mutants" expressed only mutant R subunits, and the lesions in most of these isolates inhibited binding of cAMP to mutated cAMP-binding sites. The remainder of the charge-shift mutants expressed both mutant R subunit and R subunit with wild-type gel mobilities. The origin of these "heterozygous" mutants from parental "hemizygous" cells remains a puzzle.

Activation of type I cyclic AMP-dependent protein kinases with defective cyclic AMP-binding sites

Two S49 mouse lymphoma cell variants hemizygous for expression of mutant regulatory (R) subunits of type I cyclic AMP-dependent protein kinase were used to investigate functional consequences of lesions in the putative cAMP-binding sites of R subunit. Kinase activation properties of wild-type and mutant enzymes were compared using cAMP and six site-selective analogs of cAMP. Kinases from both mutant sublines were relatively resistant to cyclic nucleotide-dependent activation, but they were fully activable by at least some effectors. Relative resistances of the mutant kinases varied from about 5-fold for analogs selective for their nonmutated sites to as much as 700-fold for analogs selective for their mutated sites; resistance to cAMP was intermediate. Apparent affinities of wild-type and mutant R subunits for [3H]cAMP were not appreciably different, but competition experiments with site-selective analogs of cAMP suggested that binding of cAMP to mutant R subunits was primarily to their nonmutated sites. Analyses of cooperativity in cyclic nucleotide-dependent activation of mutant kinases, synergism between site I- and site II-selective analogs in activating the mutant enzymes, and dissociation of bound cAMP from mutant R subunits provided additional evidence that the mutations in these strains selectively inactivated single classes of cAMP-binding sites: phenomena attributable in wild-type enzyme to intrachain interactions between sites I and II were always absent or severely diminished in experiments with the mutant enzymes. These results confirm that R subunit sequences implicated in cAMP binding by homology with other cyclic nucleotide-binding proteins actually correspond to functional cAMP-binding sites. Furthermore, occupation of either cAMP-binding site I or II is apparently sufficient for activation of cAMP-dependent protein kinase. The presence of four functional cAMP-binding sites in wild-type kinase enhances the cooperativity and sensitivity of cAMP-mediated activation.

Phosphorylation of regulatory subunit of type I cyclic AMP-dependent protein kinase: biphasic effects of cyclic AMP in intact S49 mouse lymphoma cells

Intact S49 mouse lymphoma cells were used as a model system to study the effects of cyclic AMP (cAMP) and its analogs on the phosphorylation of regulatory (R) subunit of type I cAMP-dependent protein kinase. Phosphorylation of R subunit was negligible in mutants deficient in adenylate cyclase; low levels of cAMP analogs, however, stimulated R subunit phosphorylation in these cells to rates comparable to those in wild-type cells. In both wild-type and adenylate cyclase-deficient cells, R subunit phosphorylation was inhibited by a variety of N6-substituted derivatives of cAMP; C-8-substituted derivatives were generally poor inhibitors. Two derivatives that were inactive as kinase activators (N6-carbamoylmethyl-5'-AMP and 2'-deoxy-N6-monobutyryl-cAMP) were also ineffective as inhibitors of R subunit phosphorylation. Preferential inhibition by N6-modified cAMP analogs could not be ascribed simply to selectivity for the more aminoterminal (site I) of the two cAMP-binding sites in R subunit: Analog concentrations required for inhibition of R subunit phosphorylation were always higher than those required for activation of endogenous kinase; 8-piperidino-cAMP, a C-8-substituted derivative that is selective for cAMP-binding site I, was relatively ineffective as in inhibitor; and, although thresholds for activation of endogenous kinase by site I-selective analogs could be reduced markedly by coincubation with low levels of site II-selective analogs, no such synergism was observed for the inhibitory effect. The uncoupling of cyclic nucleotide effects on R subunit phosphorylation from activation of endogenous protein kinase suggests that, in intact cells, activation of cAMP-dependent protein kinase requires more than one and fewer than four molecules of cyclic nucleotide.

A prototype epithermal neutron beam for boron neutron capture therapy

An epithermal neutron beam has been designed and tested at the Georgia Institute of Technology's 5-MW Research Reactor. The prototype facility consists of aluminum and sulfur disks in a tangential beam port for fast neutron filtration. A cadmium sheet at the port exit removes the thermal neutrons from the transmitted beam, leaving an intensely epithermal neutron beam spanning five energy decades, each contributing to the flux demanded by boron neutron capture therapy. The thermal neutron flux generated by the incident epithermal neutrons in a polyethylene head phantom peaks at a depth of 3 cm and remains above the incident thermal flux to a 7-cm depth. The beam thus provides the penetration required for treating deep-seated gliomas. Photon contamination in the prototype facility is high, and a number of basic modifications are proposed for reducing it to safer levels.