Fracture strengths of three core restorative materials supported with or without a prefabricated split-shank post

BACKGROUND: Conventional anterior cervical discectomy with fusion is thought to require postoperative neck immobilization for the promotion of bony fusion. Rigid internal fixation with anterior cervical plates may decrease graft-related complications and provide immediate stability. This stability may obviate postoperative external immobilization. METHODS: This report reviews one surgeon's experience with the use of rigid internal fixation for two-level anterior cervical discectomy and fusion for radiculopathy to promote early mobilization without external bracing. It compares outcomes and costs with a similar population of patients treated with anterior cervical discectomy and fusion who did not undergo rigid internal fixation. We compared patients who underwent two-level allograft anterior cervical discectomy and fusion with or without rigid internal fixation between 1989 and 1994 performed by a single surgeon (FJP) to evaluate the cost advantages and outcome of each procedure. All patients had clinical evidence of cervical radiculopathy unresponsive to medical therapy with magnetic resonance imaging confirmation of the appropriate nerve root impingement. Thirty-nine patients underwent two-level Cloward allograft fusion using Synthes anterior cervical locking plates, 25 underwent identical fusion without plating. Follow-up was 6 months to 4 years (mean, 31 months). RESULTS: Twenty-three of 25 patients in the nonplated group and 36 of 39 patients in the plated group achieved excellent or good outcomes using the Odom criteria. There were six complications (two major and four minor) in each group. Patients who underwent plating returned to light activities (mean, 17 vs. 29 days), driving (28 vs. 57 days), and unrestricted work (66 vs. 136 days) sooner than non-plated patients (p < 0.05, paired t test). No patient with plates was given external immobilization. CONCLUSIONS: Two-level anterior cervical discectomy and fusion with anterior plating for radiculopathy is safe, effective, and seems to provide shorter convalescence compared with conventional anterior cervical discectomy and fusion. Patients returned to unrestricted work sooner, thus reducing short-term disability. Rigid internal fixation may provide cost advantages to patients and insurance disability providers. The authors conclude that the increased cost of treatment for rigid internal fixation is more than offset by the benefits of earlier mobilization.     

There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development

The design of Ru(II) and Os(II) complexes which are photoreactive with deoxyribonucleic acid (DNA) represents one of the main targets for the development of novel molecular tools for the study of DNA and, in the future, for the production of new, metal-based, anti-tumor drugs. In this review, we explain how it is possible to make a complex photoreactive with nucleobases and nucleic acids. According to the photophysical behaviour of the Ru(II) compounds, two types of photochemistry are expected: (1) photosubstitution of a ligand by a nucleobase and another monodentate ligand, which takes place from the triplet, metal-centred (3MC) state; this state is populated thermally from the lowest lying triplet metal to ligand charge transfer (3MLCT) state; (2) photoreaction from the 3MLCT state, corresponding to photoredox processes with DNA bases. The two photoreactivities are in competition. By modulating appropriately the redox properties of the 3MLCT state, an electron transfer process from the base to the excited complex takes place, and is directly correlated with DNA cleavage or the formation of an adduct of the complex to DNA. In this adduct, guanine is linked by N2 to the alpha-position of a non-chelating nitrogen of the polyazaaromatic ligand without destruction of the complex. Different strategies are explained which increase the affinity of the complexes for DNA and direct the complex photoreactivity to sites of special DNA topology or targeted sequences of bases. Moreover, the replacement of the Ru(II) ion by the Os(II) ion in the photoreactive complexes leads to an increased specificity of photoreaction. Indeed, only one type of photoreactivity (from the 3MLCT state) is present for the Os(II) complexes because the 3MC state is too high in energy to be populated at room temperature.     

Nonradiographic assessment of enteral feeding tube position

OBJECTIVE: To determine whether a clinical, nonradiographic criterion can be used to predict when the tip of a blindly placed feeding tube is in the small intestine. DESIGN: Prospective sample. SETTING: Pediatric intensive care unit at a tertiary care children's hospital. PATIENTS: Critically ill children requiring transpyloric feeding. INTERVENTIONS: The small bowel was intubated, using a blind, bedside transpyloric feeding tube placement protocol. The feeding tube was considered to be in the small bowel when <2 mL of a 10- mL aliquot of insufflated air could be aspirated from the feeding tube. This clinical criterion was confirmed with an abdominal radiograph. MEASUREMENTS AND MAIN RESULTS: Patient age ranged from 1 month to 19 yrs (median 6 months). Weight ranged from 2.2 to 60 kg (median 4.9). Median time to feeding tube placement was 10 mins (range 5 to 60). Eighty-nine percent of the patients were mechanically ventilated, while 28% of these patients were pharmacologically paralyzed. Seventy-five feeding tubes were inserted. There were no known complications. Ninety-nine (74/75) percent of the feeding tubes were positioned in the small bowel. The inability to aspirate insufflated air correctly predicted small bowel intubation with 99% certainty (Sequential Probability Ratio Test, p = .05 and power = .80). This test incorrectly predicted the position of only one feeding tube, the 26th, which was in the stomach. Of the 74 feeding tubes positioned in the small bowel, 13 feeding tubes were in the duodenum and 61 were in the jejunum. CONCLUSIONS: The inability to aspirate insufflated air confirms the transpyloric position of a feeding tube. Other clinical criteria did not successfully predict small bowel intubation. Use of this single test may obviate confirmatory abdominal radiographs in carefully selected patients and may lead to more cost-effective and timely initiation of enteral feedings.     

Nurses'' and patients'' perceptions of most important caring behaviors in a long-term care setting

Helicobacter pylori lipopolysaccharide (LPS) expresses Lewis x and Lewis y blood group antigens that are identical to those occurring in the human gastric mucosa. During infection, antibodies against LPS, which bind to host Lewis antigens, may be induced. These consequently recognize gastric glycoprotein targets and cause autoimmune inflammation.     

Management of posttransplant lymphoproliferative disease in pediatric liver transplant recipients receiving primary tacrolimus (FK506) therapy

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) after pediatric liver transplantation has been associated with high mortality rates. METHODS: The present study examined 282 consecutive pediatric liver transplant recipients from October 1989 to June 1996 who received primary tacrolimus immunosuppression. The aim was to determine the incidence of PTLD, management strategies, and patient outcome. RESULTS: The incidence of PTLD was 13% (361282) with a mean age of 5.5+/-0.7 years (range 0.6 to 15) at diagnosis. The average time from transplantation to PTLD was 10.1+/-2.1 months. Initial treatment of PTLD consisted of reduction (3 patients) or discontinuation (33 patients) of tacrolimus and initiation of antiviral therapy (intravenous ganciclovir, 14 patients; intravenous acyclovir, 22 patients; or both, 5 patients). Alpha-interferon was used in four patients (two successfully). One patient also received gamma-interferon, chemotherapy, and radiation for a central nervous system lesion. Chemotherapy was also used in one patient with Burkitt's, whereas one patient with a pulmonary lesion received additional radiation therapy. Three patients received supportive surgery for gastrointestinal involvement, and one patient had a splenectomy for hemolysis. Overall mortality was 22% (8/36) with 5 (14%) PTLD-related deaths (disseminated disease, 4 patients; bowel perforation, 1 patient). Of 31 survivors, 23 had acute rejection at a median time of 24 days after PTLD, with 2 patients developing chronic rejection. One patient required retransplantation. Present immunosuppression consists of tacrolimus monotherapy in 14 patients, tacrolimus/prednisone in 8 patients, and none in 6 patients. CONCLUSION: In summary, PTLD can be successfully treated with reduction of immunosuppression and administration of antiviral agents in most patients. The management of rejection after PTLD requires reassessment of disease status and judicious reintroduction of immunosuppression therapy.     

Prevalence of human calicivirus infections in Kenya as determined by enzyme immunoassays for three genogroups of the virus

An epidemiological survey on human calicivirus (HuCV) infections and associated gastroenteritis in infants was conducted to clarify the prevalence of HuCV infections in infants and adults in Kenya. Enzyme immunoassays (EIAs) for three genogroups of HuCVs, Norwalk virus (NV), Mexico virus (MXV), and Sapporo virus (SV), were used to detect antigen or antibody. We tested 1,431 stool samples obtained from children younger than 6 years old with acute gastroenteritis who visited outpatient clinics in three districts in Kenya from August 1991 to July 1994. Thirty-two (2.2%) of these stool samples were positive for SV antigen. Only one (0.1%) of 1,186 samples was positive for NV antigen and none of 246 samples was positive for MXV antigen. One hundred ninety-three serum samples were tested for antibodies to NV and MXV, and 64 of them were examined for antibody to SV. The pattern of the age-related prevalence of serum antibody to NV was different from that of antibodies to MXV and SV. The acquisition of serum antibodies to HuCVs in the three genogroups appeared in early childhood, at about 1 to 2 years of age. The prevalence of serum antibody to NV was low (about 60%) throughout adulthood compared with a high prevalence of antibody (approximately 80 to 90%) to MXV and SV. These data indicate that infections with viruses in the three genogroups of HuCVs are common in Kenya, and immunological responses to NV may be different from those to MXV and SV. The EIAs for the detection of NV and MXV antigens appear to be quite specific for prototype NV and MXV strains, respectively, so that they can detect only a few strains of HuCVs related to them. Alternatively, NV and MXV caused less severe infections that did not bring children to the outpatient clinics for gastroenteritis in Kenya.