Structural study of a DNA.RNA hybrid duplex with a chiral phosphorothioate moiety by NMR: extraction of distance and torsion angle constraints and imino proton exchange rates

The solution structure of the thiophosphate-modified DNA.RNA hybrid duplex d(GCTATAApsTGG).r(CCAUUAUAGC) has been studied by NMR. Two samples with pure stereochemistry in the modified phosphate have been investigated. Two-dimensional NMR (2D NMR) methods have been applied to assign nearly all the resonances in both duplexes. Scalar coupling constants have been determined by comparing quantitative simulations with experimental double-quantum filtered COSY (DQF-COSY) cross-peaks. More than 300 distance constraints have been obtained from two-dimensional nuclear Overhauser spectroscopy (2D NOE) spectra recorded in D2O and H2O by using a complete relaxation matrix analysis as implemented in the program MARDIGRAS. This hybrid duplex presents a heteronomous structure. Riboses in the RNA strand are found in a N-type conformation typical of the A-form family as shown by the lack of H1'-H2' cross-peaks in DQF-COSY spectra and confirmed by the measured interproton distances. In contrast, the DNA strand adopts a different conformation with sugar puckers partially in the S-type domain, which is not in agreement with the A-family of structures. Coupling constants in deoxyriboses are not consistent with any single sugar conformation. Therefore, sugar pucker pseudorotation parameters are calculated according to a two-state dynamic equilibrium between N- and S-type conformers. In general, the population of major S conformer is lower than in double-stranded DNA duplexes, indicating that hybrid duplexes may be more flexible than pure DNA or RNA. The only differences observed in the spectra between the two stereoisomers studied originate from resonances of protons located near the modified phosphate. No significant differences in interproton distance have been detected, and only a slight difference of sugar pucker in the 5' neighbor has been found. The sulfur atom appears to be well-accommodated without further changes in the structure of the hybrid.

Eikenella corrodens endocarditis in an intravenous drug user: case report and literature review

A rare case of Eikenella corrodens endocarditis in an intravenous drug user is reported. Repeated blood cultures from the patient established the diagnosis of this infection. However, evaluation of the cardiac function using two-dimensional echocardiography with Doppler flow demonstrated a large pedunculated tricuspid vegetation. Also evident on this study was a dilated right ventricle with diminished contractility and regurgitation. Complete sterilization of the blood was achieved after a 2-week course of intravenous penicillin and gentamicin followed by an additional 4-week course of intravenous penicillin alone. Clinicians treating suspected IV drug users should be aware of the potential pathogenicity of this rare, facultative, anaerobic gram-negative bacillus (E corrodens). A combination of intravenous penicillin and aminoglycoside should be considered as the initial treatment followed by an additional course of intravenous penicillin for such patients with valvular vegetation.

Thought suppression and smoking cessation

Deliberate suppression of intrusive thoughts has previously been shown to be associated with higher levels of intrusion compared to monitoring without suppression. In an attempt to apply this paradigm to people attempting smoking reduction and cessation, it was demonstrated that intrusive thoughts about smoking occur frequently. Subjects reported difficulty in controlling smoking related intrusions, and ratings indicated that all subjects made attempts to suppress them. In an experimental study, instructions to suppress were associated with increased frequency of intrusion compared to the control (mention) condition. A simple distracting task was highly effective in reducing intrusion frequency to below the levels obtained in the control condition, and intrusions remained significantly lower during the second (non-suppression) period.

A structured literature review for risk assessment: EMF and human health risk

The volume of publications on any given topic makes it difficult to select an appropriate subset of publications for review by an expert panel. This paper proposes a method for selecting a subset using a protocol that attempts to order publications based upon good research methods. The protocol was followed by graduate students with no expert knowledge of the area they were reviewing. They reduced 11730 articles on the topic of EMF and Health risk to 68 articles that were reviewed by an expert panel. The interrater reliability was 96% and 94% of the relevant articles were captured by this process.

A 25-year experience with renal tumors of childhood

A retrospective analysis of the medical records of 234 children with renal tumors managed over a 25-year period at the Children's Memorial Medical Center was undertaken to evaluate long-term morbidity and mortality. There was a significant increase in survival over the years of the study. The 5-year survival for patients treated during the period 1985 to 1989 was 94% versus 68% for the period 1965 to 1969. Thirty-three children have died, 15 with known disease progression. Long-term morbidity included scoliosis (39), cardiorespiratory insufficiency (13), hypertension (7), renal insufficiency (7), small bowel obstruction (10), chest wall deformity (3), amenorrhea (1), leg length discrepancy (1), and 1 patient with an esophageal stricture. One patient with cardiomyopathy secondary to adriamycin has recently undergone cardiac transplantation. Five patients with renal insufficiency have required dialysis. Of these five, one patient has had two renal transplants. The presence of distant metastases and positive hilar or regional lymph nodes were the only findings at operation that were associated with an increased mortality (P = .005). There was a significantly increased mortality in those children operated on by general surgeons or urologists at other hospitals (11/43) versus those operated upon at our hospital (22/191) (P = .033). There was no statistical difference in the staging or histology among these children. We feel that the careful and systematic approach of a radical nephrectomy assures accurate staging of the tumor removing gross and microscopic disease in the abdomen.

Coagulase-negative staphylococci in conjunctivitis and blepharitis

Coagulase-negative staphylococcus (C-NS) are regarded as normal flora of the lids and conjunctiva. The ability of these organisms to cause conjunctivitis and blepharitis can be overlooked or disregarded. To elucidate the role of individual C-NS species in these eye diseases we compared Staphylococcus sp. isolated from the conjunctiva and lids of 50 healthy volunteers with 248 strains of Staphylococcus isolated from patients with staphylococcal conjunctivitis or blepharitis. S. epidermidis was the most frequent species isolated from the conjunctiva and lids of both groups. S. aureus was isolated only from infected patients. No individual C-NS species was found to be significantly associated with eye disease, but the colony count of C-NS after isolation was a useful indicator of conjunctivitis and blepharitis. The ability of Staphylococcus to ferment mannitol or mannose was associated with isolates only from infected patients.

An audit of treatment of genital warts: opening the feedback loop

An audit of the treatment of patients (100 men and 90 women) presenting with a first episode of anogenital warts to the Genitourinary Medicine Department at Leeds General Infirmary was performed. Treatment of patients was monitored for a period of 6 months from the time of presentation. The management of patients with genital warts lacked a clearly defined strategy and treatment was unselective and poorly monitored. Excluding patients who defaulted, at follow-up 44 (44%) men and 36 (38%) women still had genital warts at 3 months. Of those patients clear of warts at 3 months, the mean time to remission for men and women was 7.1 and 8.3 weeks respectively. Podophyllin 25% in tincture of benzoin was by far the predominant therapeutic modality used. A total of 96 (96%) men and 76 (84%) women received treatment with podophyllin. Both male and female patients had a mean of 5 treatments with podophyllin 25% (range 1-19 and 1-12 respectively). Physical methods of treatment i.e. cryotherapy and electrocautery, were underutilized, both as primary therapies and when topical agents had failed. Patients saw an average of 3 (range 1-7) doctors over the course of their treatment. Patients with warts affecting 2 or more sites, male patients with anal/perianal warts, and female patients with cervical and vaginal warts had higher failure rates from treatment at 3 months. On the basis of these findings, specific treatment protocols for the management of anogenital warts have been devised.

Pulmonary changes following extracorporeal membrane oxygenation: autopsy study of 23 cases

Extracorporeal membrane oxygenation (ECMO) has become an established mode of therapy in many centers for potentially fatal neonatal respiratory failure refractory to conventional therapy. We reviewed the findings of 23 autopsies of patients placed on ECMO therapy during the period from 1988 to 1992 at our institution in order to document the pulmonary histopathologic changes and to correlate such changes with the duration of treatment. Interstitial and intra-alveolar hemorrhages, as well as hyaline membrane formation, were the most common findings during the first few days of therapy. Reactive epithelial hyperplasia (bronchial and type II pneumocytes), squamous metaplasia, and smooth muscle hyperplasia were observed as early as 2 to 3 days after initiation of ECMO therapy. Interstitial fibrosis was noted only after 7 days of ECMO therapy. In three patients treated for 15, 19, and 21 days there was replacement of the terminal airways and alveoli by tall columnar and mucin-producing epithelium. Alveolar and bronchiolar calcifications were noted in seven of the 23 cases in this series. Pulmonary vascular changes were seen in association with persistent fetal circulation, meconium aspiration, and respiratory distress syndrome. These changes are most likely due to the compounded effect of ECMO and the underlying pulmonary insult.

Effect of intravenous erythromycin on postoperative ileus

We attempted to determine whether the administration of erythromycin shortens the period of postoperative ileus by a prospective, double-blind, placebo-controlled study. Seventy-seven patients were randomized and included in the statistical calculations. The patients were stratified according to the operation performed (cholecystectomy, celiotomy, or other major abdominal operations). Forty-one patients (group 1) received 250 mg erythromycin intravenously every 8 h for nine doses upon admission to the recovery room. Thirty-six patients (group 2) received placebo. The time (in hours) to first passage of flatus, first liquid meal, first bowel movement, and total length of hospital stay was recorded. There was no significant difference between group 1 and group 2 in time to first flatus (54.9 +/- 29 vs. 53.9 +/- 27 h, respectively), first meal (70.4 +/- 44 vs. 71.7 +/- 65), first bowel movement (81.8 +/- 32 vs. 80.1 +/- 28), or length of hospital stay (185.2 +/- 183 vs. 182.1 +/- 163). Erythromycin, in the dosage tested in this study, does not seem to alter clinical parameters of gastrointestinal motility after an abdominal operation. New prokinetic agents may deserve further studies.

Cisplatin, vincristine, and fluorouracil therapy for hepatoblastoma: a Pediatric Oncology Group study

PURPOSE

To estimate the disease-free survival rate in children with grossly resected hepatoblastoma treated with cisplatin, vincristine, and fluorouracil (CDDP/VCR/FU) and to assess the disease-response rate and disease-free survival (DFS) rate in children with unresectable or metastatic tumors treated with this combination.

PATIENTS AND METHODS

Sixty assessable patients with hepatoblastoma received therapy with five (stage I and II) to seven (stage III and IV) courses of CDDP (90 mg/m2), day 1, and VCR (1.5 mg/m2), and FU (600 mg/m2), day 3.

RESULTS

Nineteen of 21 patients with stage I or II disease survive free of disease (actuarial survival, 90% at 5 years). Twenty-four of 31 patients with stage III disease achieved a complete remission (CR) after chemotherapy and surgical excision; actuarial DFS at 4 years is 67%. Only one of eight patients with stage IV disease achieved a remission and survives.

CONCLUSION

Relatively brief exposure to chemotherapy with CDDP/VCR/FU provided excellent disease control to patients with grossly resected tumors. In patients with initially unresectable disease, this therapy provides a response rate and DFS rate comparable to regimens that contain doxorubicin (DOX).

Choledochal duct cyst: resection with physiologic reconstruction

BACKGROUND

The accepted surgical treatment of choledochal duct cyst is complete excision and enteric drainage through an intestinal conduit. Peptic ulceration and fat malabsorption have been reported after Roux-en-Y reconstruction. Such long-term complications may be avoided by a technique that simulates normal physiology.

METHODS

Twenty-one patients have undergone resection of a choledochal duct cyst in the past 12 1/2 years. The pathologic duct is resected to the level of normal mucosa. A short segment of jejunum with a intussusception valve (1.5 to 2 cm) is interposed between the common hepatic duct and the duodenum. The medical records and all radiographs of each patient were reviewed. Eighteen children were reexamined or the parents were contacted by phone.

RESULTS

Twenty of 21 patients recovered without major perioperative complications. Twelve of them are well and have no symptoms at 3 to 12+ years (mean, 6 years) after operation. Four children are currently well 6 to 19 months after operation. Three children were well when lost to follow-up. Two patients have radiographic evidence of incompetence of the interposition valve. One of these, who initially underwent operation at 9 months of age, was reexplored at 10 months and at 10 years for a stricture at the hepaticojejunal anastomosis. The other, a 7-year-old girl who was admitted with jaundice and pancreatitis, has had episodic abdominal pain for 7 years after operation but is well.

CONCLUSIONS

The valved jejunal interposition hepaticoduodenostomy offers superior biliary reconstruction after excision of a choledochal duct cyst. Normal physiology is simulated, with bile draining directly into the duodenum. A short conduit prevents stasis, and biliary reflux is minimized with the addition of an intussusception valve.

Chemotherapy can convert unresectable hepatoblastoma

The surgical evaluation and management of children with hepatoblastoma has changed with recent advances in imaging modalities and preoperative chemotherapy. Pediatric Oncology Group (POG) Study no. 8697 has followed 63 patients with hepatoblastoma from 1986 to 1991. Twenty-six patients underwent primary tumor resection followed by chemotherapy consisting of cisplatin, vincristine, and 5-fluorouracil (group I). Thirty-seven patients with "unresectable" tumors received preoperative chemotherapy. Twenty-nine of these patients responded to chemotherapy and 26 underwent delayed surgical resection (group II). Eight patients had an inadequate response to chemotherapy; two have had successful liver transplantation and six are dead of disease progression. "Unresectable tumor" involved both liver lobes (25 patients), encased the inferior vena cava (2), involved adjacent tissues (1), involved the hepatic veins (2), or was deemed too large for safe resection (7). Two patients had distant metastases. The reason for an unresectable designation was not reported in five patients. The determination for an unresectable designation included exploratory laparotomy in 14 patients, angiogram in 7, computed tomography scan in 20, and magnetic resonance imaging in 3 patients. Operative times and transfusion requirements were similar in both groups. Perioperative complications were higher in patients in group II. There was no mortality and only minor morbidity associated with chemotherapy in each group. In both groups 77% of the patients are in complete remission after 13 to 54 months. Preoperative chemotherapy can allow successful resection of initially "unresectable" hepatoblastoma. Primary resection that may result in exsanguination should be postponed and chemotherapy given.

The nuts and bolts of organizing and initiating a pediatric transport team. The Sutter Memorial experience

Specialized interfacility transport teams are capable of delivering critical care medicine to the patient at the referring hospital and while en route to the tertiary care center. To do so effectively, however, requires adequate financial and human resources; management of equipment, supplies and personnel; ongoing education for transport team members; and an aggressive quality assurance program. Team members and team management should always be prepared for worst-case scenarios, and develop a method for problem resolution as troublesome issues arise. The ultimate goal of serving the needs of the critically ill child can be consistently met only if there is a high level of commitment of all involved--from the hospital administrator and medical director to the transport coordinator and team members.

Comparison of positive and negative intrusive thoughts and experimental investigation of the differential effects of mood

The similarity between positive and negative intrusive thoughts is considered for both recently occurring, personally relevant intrusions and for the same intrusions occurring during an experimental task involving self-monitoring. The results indicate that positive and negative intrusions differ in most respects. There was evidence that increasing the frequency of negative thinking is associated with a deterioration of mood. In a subsequent experiment, induced happy and sad moods were shown to differentially affect frequency of intrusions in a fashion consistent with mood congruency effects previously found in experiments on the effect of mood on memory. The implications of these findings for disorders involving the experience of intrusive thoughts such as OCD and depression are discussed.

Morbidity associated with total colon Hirschsprung's disease

Increased awareness of total colon Hirschsprung's disease (TCH) has led to improvement in patient care and a decrease in the associated mortality. Morbidity has remained high and necessitates close follow-up to prevent the development of life-threatening complications. We retrospectively reviewed the records of 20 children with TCH treated at this institution since 1961. Follow-up averaged 40.4 months (range, 1 to 150). All patients were diverted with an ileostomy or jejunostomy. Eight children had a Swenson pull-through, three had a Martin procedure, and eight had a Kimura procedure. One child with multiple anomalies died after his ileostomy. There were no postoperative deaths. Complications following ileostomy and pull-through procedures included excessive fluid losses, wound infections, stoma problems, and bouts of enterocolitis. Three children had no reported complications. Seventeen complications were reported in eight children with the Kimura procedure, 10 in the three children with the Martin procedure, and 22 in the eight children with the Swenson procedure. These complications resulted in an average of 4.4 admissions per patient (range, 1 to 11) with an average length of stay of 96 days per patient (range, 10 to 598). Twelve patients required an average of 63 days of total parenteral nutrition and eight needed 328 days (range, 23 to 867) of supplemental nasogastric feedings. Ten patients required at-home rectal irrigations and seven patients required rectal dilations. Nearly half of all patients were kept on antimotility agents long term. Since 1985 we have performed the Kimura procedure for all children with TCH and have seen a decrease in morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Necrotizing enterocolitis following intrauterine blood transfusion

Intravascular intrauterine transfusion allows a more sophisticated and exact approach to the management of severe Rh hemolytic disease. This technique involves direct manipulation of the fetal umbilical vessels; its hazards include umbilical cord trauma and thrombosis or emboli. The consequences of such events in utero are largely unknown. In this case necrotizing enterocolitis occurred in a full-term infant after three intrauterine intravascular transfusions.

Pediatric falls from heights

Injuries resulting from falls from heights still constitute a significant portion of urban trauma. At this pediatric trauma center, 70 children were admitted from 1985 to 1988 after sustaining a fall of 10 feet or greater or at least one story. The mean patient age was 5 years and 68% of the patients were boys. Seventy-eight percent of falls occurred from 2 stories or less and usually took place at or near the home. Most patients sustained a single major injury and all survived. The majority of injuries involved the head or skeleton and residual functional deficits were uncommon. The incidence of falls from heights has remained high in urban areas despite public education and building codes that require window guards and safety rails.

Goldmann tonometry and fluorescein solution: a way to avoid contact lens staining

Topical instillation of fluorescein during standard Goldmann tonometry may cause subsequent contact lens staining. We evaluated a method of Goldmann tonometry that uses only a small amount of fluorescein. In this experimental technique, the fluorescein is applied only to the tip of the applanation cone with fluorescein-coated tissue paper. Thirty patients had their intraocular pressures (IOPs) determined by this method. The IOP measurements were then repeated on the same eyes after instillation of fluorescein directly onto their eyes. In addition, 20 soft contact lens wearers had their IOPs determined by the experimental method, with contact lenses fitted immediately after the measurements. There was no statistically significant difference between the IOPs measured by the standard technique and by the experimental method. In addition, no fluorescein staining was detected in the 20 soft contact lenses examined. Our results suggest that the proposed method is accurate and useful in determining IOP prior to soft contact lens fitting.

The impact of level 1 pediatric trauma center designation on demographics and financial reimbursement

A retrospective analysis of medical and financial records of trauma patients admitted over a 4-year period was undertaken to determine the impact of level 1 pediatric trauma center designation on demographics and financial reimbursement. Three hundred fifty-four patients were admitted from November 1, 1985, to October 31, 1986 (Prelevel 1 designation [PREL1]). Five hundred seven patients were admitted from November 1, 1986, to October 31, 1987 (Postlevel 1 designation [PostL1]) (P less than .005). Mechanisms of injury were similar in both groups, with falls being most prevelant (PreL1, 50.8%; PostL1, 43.4%). The magnitude of injuries in the PostL1 period, as expressed by Pediatric Trauma Scores and Injury Severity Scores, did not change significantly. The types of injuries, as indicated by organ systems involved, did not change. The exception was thoracic injuries, which increased from 1.7% to 4.5% (P = .037). Total hospital charges per patient increased ($5,820 PreL1; $7,691 PostL1) (P = .034). Collection rates did not change (77.6% PreL1; 76.4% PostL1). The institution incurred a financial loss per patient of $1,149 PreL1 and $1,795 PostL1 (P = .055). Years 2 and 3 PostL1 designation were analyzed to identify trends (year 2 PostL1: November 1, 1987 to October 31, 1988 [488 patients]; year 3 PostL1: November 1, 1988 to October 31, 1989 [459 patients]). The distribution of Pediatric Trauma Scores and Injury Severity Scores did not change. Total hospital charges per patient remained fairly constant ($8,082 year 2 PostL1; $7,276 year 3 PostL1). Unreimbursed costs increased significantly compared with losses during the PostL1 period ($4,262 year 2 PostL1, P less than .005; $2,799 year 3 PostL1, P = .04).(ABSTRACT TRUNCATED AT 250 WORDS)

Graft-versus-host disease following ECMO

Since 1973, over 3,000 newborns have been treated worldwide for respiratory failure with extracorporeal membrane oxygenation (ECMO). ECMO requires transfusion of numerous blood products including platelets and packed red blood cells. Transfusion-associated graft-versus-host disease (GVHD) developed in one of the authors' patients following treatment with ECMO. ECMO exposes newborn infants to a large number of blood components. Although a rare complication, GVHD can be prevented by irradiating blood products prior to transfusion. We now irradiate all blood products prior to use during ECMO and recommend that other institutions do the same.

The relationship among guilt, dysphoria, anxiety and obsessions in a normal population--an attempted replication

The results of a previous study indicated that guilt as rated on the Perceived Guilt Index (PGI), predicted unpleasant intrusive thoughts, but self-reported anxiety and depression did not. In the present investigation, subjects indicated whether or not they experienced both pleasant and unpleasant intrusive thoughts, their frequency and a rating of how pleasant or unpleasant these thoughts were. They also completed self report ratings of depression, anxiety, obsessional ritualizing, and the PGI. Results of a regression analysis indicate that the best standardised questionnaire predictor of unpleasant intrusive thoughts is depression as rated on the BDI, and anxiety as rated on the BAI. The best standardised questionnaire predictor of pleasant intrusive thoughts is low anxiety. The PGI does not independently predict pleasant or unpleasant intrusive thoughts.

Increased nerve growth factor receptor mRNA in contused rat spinal cord

Peripheral nerve injury induces the expression of nerve growth factor receptor (NGFR). To determine whether a similar induction results from injury of the spinal cord, NGFR mRNA content was determined using Northern blot hybridization analysis of total RNA from spinal cords of rats contused in the mid-thoracic region. By four days after contusion NGFR mRNA was significantly increased in the thoracic segments that included the injury site. The induction was maximal at 7 days, about 5- to 7-fold the level of uninjured controls, and remained 4 times higher than controls at 14 and 28 days after injury. These results suggest that axotomy in the CNS may also trigger the molecular mechanism(s) leading to up-regulation of NGFR expression.

Transfusion requirements in conservative nonoperative management of blunt splenic and hepatic injuries during childhood

Nonoperative management of splenic and hepatic injuries in children is safe, and the majority of those with isolated injuries do not require blood transfusion. Thirty-seven children were treated for blunt splenic or hepatic trauma from November 1983 to September 1989. There was one death in a patient with a lethal head injury. No operations were performed on those with isolated splenic or hepatic injuries. Three of those with multiple injuries underwent delayed laparotomy. Two had perirenal and retroperitoneal hematomas without active bleeding, and one had a bowel obstruction secondary to an intramural jejunal hematoma. There were no late complications related to the splenic or hepatic injuries. Eight children (22%) required surgery for other injuries. Twelve children were not transfused, including the majority (8/11) of those with isolated splenic or hepatic injury. The hematocrit of four of these children fell to below 28% and this anemia was well-tolerated. Two children with bleeding disorders (factor VIII [antihemophilic factor] and factor XII [Hageman factor] deficiency) did not require packed red blood cells transfusion. Two clinically distinct groups of children received blood transfusions: (1) eight patients with multiple injuries were transfused during initial resuscitation when unstable or during early operation for other system trauma (mean, 62.0 mL blood/kg body weight); and (2) three hemodynamically stable patients with isolated injuries and 14 stable patients with multiple injuries were transfused empirically after initial resuscitation solely because of decreasing blood counts. They received an average of 16.5 and 21.1 mL blood/kg body weight, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)