Incidence of spine surgery in the South African private healthcare sector: ten-year trends within a large open medical scheme

PURPOSE

Studies from developed countries suggest a dramatic increase in the utilization of spine surgery in recent decades, however less is known about spine surgery rates in the developing world. The aim of this study was to investigate ten-year trends in the incidence of spine surgery within South Africa's largest open medical scheme.

METHODS

This retrospective review included adult inpatient spine surgeries funded by the scheme between 2008 and 2017. The incidence of spine surgery was investigated by age group-overall and for degenerative pathologies, fusion and instrumentation. Surgeons per 100,000 members were determined. Trends were evaluated by linear regression and by crude 10-year change in incidence.

RESULTS

A total of 49,575 spine surgeries were included. The incidence of surgery for lumbar degenerative pathology showed a significant upward trend among 60-79 year olds but declined among 40-59 year olds. The incidence of lumbar fusion and lumbar instrumentation declined significantly among 40-59 year olds with little change among 60-79 year olds. The ratio of orthopaedic spinal surgeons decreased from 10.2 to 6.3 per 100,000 members whereas the ratio of neurosurgeons decreased from 7.6 to 6.5 per 100,000.

CONCLUSION

Spine surgery in the South African private healthcare sector bears some similarity to developed countries in that it is dominated by elective procedures for degenerative pathology. However, the findings did not reflect the marked increases in the utilization of spine surgery reported elsewhere. It is hypothesized that this may be partly related to differences in the supply of spinal surgery.

Ifosfamide, gemcitabine, and vinorelbine is an effective salvage regimen with excellent stem cell mobilization in relapsed or refractory pediatric Hodgkin lymphoma

We describe 12 pediatric patients (8-16 years) with primary refractory (N = 6) or first relapse (N = 6) Hodgkin lymphoma (HL) treated with ifosfamide, gemcitabine, and vinorelbine (IGEV). The overall response rate to IGEV was 100%, with seven (58%) complete responses (CR) and five (42%) partial responses. Successful CD34⁺ stem cell mobilization was achieved in all patients. Following subsequent autologous stem cell transplantation, 10 patients (83%) achieved CR. At a median follow-up of 71 months, 11 patients had no evidence of disease. Five-year second event-free survival and overall survival were 83% ± 11.0% and 90.0% ± 9.5%, respectively. IGEV is an effective salvage regimen for children with relapsed/refractory HL.

SCID genotype and 6-month posttransplant CD4 count predict survival and immune recovery

The Primary Immune Deficiency Treatment Consortium (PIDTC) performed a retrospective analysis of 662 patients with severe combined immunodeficiency (SCID) who received a hematopoietic cell transplantation (HCT) as first-line treatment between 1982 and 2012 in 33 North American institutions. Overall survival was higher after HCT from matched-sibling donors (MSDs). Among recipients of non-MSD HCT, multivariate analysis showed that the SCID genotype strongly influenced survival and immune reconstitution. Overall survival was similar for patients with RAG, IL2RG, or JAK3 defects and was significantly better compared with patients with ADA or DCLRE1C mutations. Patients with RAG or DCLRE1C mutations had poorer immune reconstitution than other genotypes. Although survival did not correlate with the type of conditioning regimen, recipients of reduced-intensity or myeloablative conditioning had a lower incidence of treatment failure and better T- and B-cell reconstitution, but a higher risk for graft-versus-host disease, compared with those receiving no conditioning or immunosuppression only. Infection-free status and younger age at HCT were associated with improved survival. Typical SCID, leaky SCID, and Omenn syndrome had similar outcomes. Landmark analysis identified CD4+ and CD4+CD45RA+ cell counts at 6 and 12 months post-HCT as biomarkers predictive of overall survival and long-term T-cell reconstitution. Our data emphasize the need for patient-tailored treatment strategies depending upon the underlying SCID genotype. The prognostic significance of CD4+ cell counts as early as 6 months after HCT emphasizes the importance of close follow-up of immune reconstitution to identify patients who may need additional intervention to prevent poor long-term outcome.

Outcomes of Measurable Residual Disease in Pediatric Acute Myeloid Leukemia before and after Hematopoietic Stem Cell Transplant: Validation of Difference from Normal Flow Cytometry with Chimerism Studies and Wilms Tumor 1 Gene Expression

We enrolled 150 patients in a prospective multicenter study of children with acute myeloid leukemia undergoing hematopoietic stem cell transplantation (HSCT) to compare the detection of measurable residual disease (MRD) by a "difference from normal" flow cytometry (ΔN) approach with assessment of Wilms tumor 1 (WT1) gene expression without access to the diagnostic specimen. Prospective analysis of the specimens using this approach showed that 23% of patients screened for HSCT had detectable residual disease by ΔN (.04% to 53%). Of those patients who proceeded to transplant as being in morphologic remission, 10 had detectable disease (.04% to 14%) by ΔN. The disease-free survival of this group was 10% (0 to 35%) compared with 55% (46% to 64%, P < .001) for those without disease. The ΔN assay was validated using the post-HSCT specimen by sorting abnormal or suspicious cells to confirm recipient or donor origin by chimerism studies. All 15 patients who had confirmation of tumor detection relapsed, whereas the 2 patients with suspicious phenotype cells lacking this confirmation did not. The phenotype of the relapse specimen was then used retrospectively to assess the pre-HSCT specimen, allowing identification of additional samples with low levels of MRD involvement that were previously undetected. Quantitative assessment of WT1 gene expression was not predictive of relapse or other outcomes in either pre- or post-transplant specimens. MRD detected by ΔN was highly specific, but did not identify most relapsing patients. The application of the assay was limited by poor quality among one-third of the specimens and lack of a diagnostic phenotype for comparison.

Haematopoietic stem cell transplantation for refractory Langerhans cell histiocytosis: outcome by intensity of conditioning

Patients with Langerhans cell histiocytosis (LCH) refractory to conventional chemotherapy have a poor outcome. There are currently two promising treatment strategies for high-risk patients: the first involves the combination of 2-chlorodeoxyadenosine and cytarabine; the other approach is allogeneic haematopoietic stem cell transplantation (HSCT). Here we evaluated 87 patients with high-risk LCH who were transplanted between 1990 and 2013. Prior to the year 2000, most patients underwent HSCT following myeloablative conditioning (MAC): only 5 of 20 patients (25%) survived with a high rate (55%) of transplant-related mortality (TRM). After the year 2000 an increasing number of patients underwent HSCT with reduced intensity conditioning (RIC): 49/67 (73%) patients survived, however, the improved survival was not overtly achieved by the introduction of RIC regimens with similar 3-year probability of survival after MAC (77%) and RIC transplantation (71%). There was no significant difference in TRM by conditioning regimen intensity but relapse rates were higher after RIC compared to MAC regimens (28% vs. 8%, P = 0·02), although most patients relapsing after RIC transplantation could be salvaged with further chemotherapy. HSCT may be a curative approach in 3 out of 4 patients with high risk LCH refractory to chemotherapy: the optimal choice of HSCT conditioning remains uncertain.

Comparison of outcomes of hematopoietic stem cell transplantation without chemotherapy conditioning by using matched sibling and unrelated donors for treatment of severe combined immunodeficiency

BACKGROUND

Patients with severe combined immunodeficiency disease who have matched sibling donors (MSDs) can proceed to hematopoietic cell transplantation (HCT) without conditioning chemotherapy.

OBJECTIVE

We sought to determine whether the results of HCT without chemotherapy-based conditioning from matched unrelated donors (URDs), either from volunteer adults or umbilical cord blood, are comparable with those from MSDs.

METHODS

We performed a multicenter survey of severe combined immunodeficiency transplantation centers in North America, Europe, and Australia to compile retrospective data on patients who have undergone unconditioned HCT from either URDs (n = 37) or MSDs (n = 66).

RESULTS

Most patients undergoing URD HCT (92%) achieved donor T-cell engraftment compared with 97% for those with MSDs; however, estimated 5-year overall and event-free survival were worse for URD recipients (71% and 60%, respectively) compared with MSD recipients (92% and 89%, respectively; P < .01 for both). URD recipients who received pre-HCT serotherapy had similar 5-year overall survival (100%) to MSD recipients. The incidences of grade II to IV acute and chronic graft-versus-host disease were higher in URD (50% and 39%, respectively) compared with MSD (22% and 5%, respectively) recipients (P < .01 for both). In the surviving patients there was no difference in T-cell reconstitution at the last follow-up between the URD and MSD recipients; however, MSD recipients were more likely to achieve B-cell reconstitution (72% vs 17%, P < .001).

CONCLUSION

Unconditioned URD HCT achieves excellent rates of donor T-cell engraftment similar to that seen in MSD recipients, and reconstitution rates are adequate. However, only a minority will have myeloid and B-cell reconstitution, and attention must be paid to graft-versus-host disease prophylaxis. This approach might be safer in children ineligible for intense regimens to spare the potential complications of chemotherapy.

Sequential combination chemotherapy in human breast cancer: a basis for increased antineoplastic activity and bone marrow protection

These studies were designed to develop procedures that would capitalize on the growth inhibitory effects of tamoxifen (Tam) and methotrexate (MTX) in breast cancer, while protecting bone marrow with a priming dose of 5-fluorouracil (5-FU). High-dose MTX (10 microM) cytotoxicity is maintained in MCF-7 breast cancer cells but reduced in human bone marrow by a priming and nontoxic dose of 5-FU (10 microM). MTX cytotoxicity is decreased in MCF-7 breast cancer cells when the selective estrogen receptor modulator (SERM) Tam (10 microM) is administered 24 hours prior to 5-FU (10 microM) followed two hours later by MTX (early Tam) resulting in a growth rate of 57.42 +/- 4.38% of the control rate. However, when breast cancer cells are exposed to Tam 24 hours after 5-FU + MTX (late Tam), the interaction between MTX and Tam is not antagonistic, the percentage of the control is 29.47 +/- 4.54%. Bone marrow exposure to these drug combinations exhibits a protective effect to the MTX cytotoxicity, with the early Tam combination yielding 59.45 +/- 16.38% of the control for MTX alone. These studies suggest that a) Tam in combination with a priming dose of 5-FU protects bone marrow from MTX cytotoxicity, b) the interactions between Tam and MTX are sequence-dependent, c) Tam decreases the effect of MTX when Tam administration precedes MTX.

Raloxifene and selective cell cycle specific agents: a case for the inclusion of raloxifene in current breast cancer treatment therapies

BACKGROUND

Breast cancer patients are at increased risk of osteoporosis. Contributing factors include age and/or chemotherapy. The selective estrogen modulator, raloxifene (RAL), effective in the prevention of breast cancer and approved for the treatment and prevention of osteoporosis, may prove beneficial in current breast cancer treatment modules. The purpose of this study was to evaluate RAL in combination with 5-fluorouracil (5-FU) and trimetrexate (TMX) to determine the most effective sequence in which to administer these cell cycle specific agents while taking into consideration the cellular mechanism of action. The goal was to maintain cytotoxicity to breast cancer cells and capitalize on the selective estrogen receptor modulatory effects of RAL.

MATERIALS AND METHODS

MCF-7 cells were exposed to (i) TMX, 5-FU or RAL alone, or (ii) RAL 24 h prior to 5-FU followed 2 h later by TMX, or (iii) 5-FU 2 h prior to TMX followed 24 h later by RAL. The cell viability was determined using the Quick Cell Proliferation Assay.

RESULTS

The growth rate of MCF- 7 cells exposed to early RAL was 68.25 +/- 4.11% that of the control, however, late RAL exposure produced a growth of 34.75 +/- 4.79% that of the control. Late RAL maintained the cytotoxicity of the regimen. The findings were further supported by cell flow cytometry and Western blot analysis data.

CONCLUSION

RAL given prior to 5-FU/TMX significantly compromised cytotoxicity to breast cancer cells.

Torticollis as a sign of cervico-thoracic epidural haematoma in an infant with severe haemophilia A

We describe the case of a spinal epidural haematoma in an infant with severe haemophilia A. Initial signs and symptoms were non-specific resulting in delay of the diagnosis and more definitive therapy. The patient eventually developed torticollis, acute flaccid paralysis of the upper extremities, and respiratory distress, prompting radiological examination of the spinal cord. The patient was treated with recombinant FactorVIII and laminectomy. Neurological recovery was complete 3 months following the event. We hypothesize that infants with haemophilia may be at higher risk for this rare complication because of their increasing mobility, frequent falls while cruising furniture, and lack of prophylactic factor replacement. Non-specific signs such as irritability without a focus should alert the clinician to this diagnostic possibility. Torticollis should prompt rapid radiological evaluation of the cervical spine with magnetic resonance imaging to avoid delay in diagnosis.

Second malignancy following high-dose therapy and autologous stem cell transplantation: incidence and risk factor analysis

To establish incidence and risk factors for development of second malignant neoplasms after high-dose chemo/radiotherapy (HDT) and autologous hematopoietic stem cell transplantation (AHSCT), the case files of 800 consecutive patients who underwent AHSCT at our institution between June 1982 and December 2000 were reviewed. In all, 26 patients developed 29 second malignancies (nine myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML), 16 solid tumors and four lymphoproliferative disorders (LPDs)) for a 15-year cumulative incidence of 11% (95% confidence interval (CI), 5-18%). These second tumors occurred at a median of 68 (range 1.5-177) months following AHSCT. The relative risk (RR) compared to the general population of developing a second malignancy following AHSCT was 3.3 (CI 2.2-4.7) P<0.001. The RR of developing MDS/AML, LPD and a solid tumor was 47.2 (CI 21.5-89.5) P<0.001, 8.1 (2.2-20.7) P=0.002 and 1.98 (1.1-3.2) P=0.009, respectively. In multivariate analysis, age >or=35 years at the time of AHSCT (P=0.001) and an interval from diagnosis to AHSCT >or=36 months (P=0.03) were associated with a greater risk of developing a second malignancy. Patients who have undergone HDT and AHSCT are at significant risk for developing a second malignancy and should receive indefinite follow-up.

The interaction of the steroidal antagonist faslodex and methotrexate

Faslodex (FAS, ICI 182, 780), a novel steroidal estrogen antagonist decreased high-dose methotrexate (MTX) cytotoxicity in MCF-7 breast cancer cells. When FAS is given at least 24 hr prior to MTX, the resultant interaction is antagonistic. However, when breast cancer cells are exposed to FAS 24 hr after MTX, the interaction between FAS and MTX is not antagonistic. The proliferation of cells exposed to 0.1 microM FAS and 10 microM MTX alone or in combination with FAS 24 hr prior to MTX was in the following order: FAS>FAS 24 hr prior to MTX>MTX. MTX administration 24 hr prior to FAS had the following inhibitory effects on the growth of cells: MTX 24 hr prior to FAS >MTX>FAS 24 hr prior to MTX>FAS>control (no drug exposure). To determine if the antagonistic interaction between FAS and MTX was a function of sequence and time, cells were exposed to FAS 24 hr and 36 hr prior to MTX exposure. The percentages of control rates were 42.70 +/- 4.60% and 57.89 +/- 0.55%, respectively, from a 24 hr and 36 hr exposure of FAS prior to MTX. The growth rates after 24 and 36 hr exposures to MTX alone were 30.30 +/- 0.61% and 33.11 +/- 2.57% of control rates, respectively. These studies suggest that: a) the interactions between FAS and MTX are sequence-dependent; b) FAS antagonizes the effect of MTX when FAS administration precedes MTX, and c) FAS antagonism to MTX is a function of time.

Nitrate removal effectiveness of a riparian buffer along a small agricultural stream in western Oregon

The Willamette Valley of Oregon has extensive areas of poorly drained, commercial grass seed lands. Little is know about the ability of riparian areas in these settings to reduce nitrate in water draining from grass seed fields. We established two study sites with similar soils and hydrology but contrasting riparian vegetation along an intermittent stream that drains perennial ryegrass (Lolium perenne L.) fields in the Willamette Valley of western Oregon. We installed a series of nested piezometers along three transects at each site to examine NO3-N in shallow ground water in grass seed fields and riparian areas. Results showed that a noncultivated riparian zone comprised of grasses and herbaceous vegetation significantly reduced NO3-N concentrations of shallow ground water moving from grass seed fields. Darcy's law-based estimates of shallow ground water flow through riparian zone A/E horizons revealed that this water flowpath could account for only a very small percentage of the streamflow. Even though there is great potential for NO3-N to be reduced as water moves through the noncultivated riparian zone with grass-herbaceous vegetation, the potential was not fully realized because only a small proportion of the stream flow interacts with riparian zone soils. Consequently, effective NO3-N water quality management in poorly drained landscapes similar to the study watershed is primarily dependent on implementation of sound agricultural practices within grass seed fields and is less influenced by riparian zone vegetation. Wise fertilizer application rates and timing are key management tools to reduce export of NO3-N in stream waters.

High-dose melphalan, etoposide, total-body irradiation, and autologous stem-cell reconstitution as consolidation therapy for high-risk Ewing's sarcoma does not improve prognosis

PURPOSE

To determine whether consolidation therapy with high-dose melphalan, etoposide, and total-body irradiation (TBI) with autologous stem-cell support would improve the prognosis for patients with newly diagnosed metastatic Ewing's sarcoma (ES).

PATIENTS AND METHODS

Thirty-two eligible patients with newly diagnosed ES metastatic to bone and/or bone marrow were enrolled onto this study. Treatment was initially comprised of five cycles of induction chemotherapy (cyclophosphamide, doxorubicin, and vincristine alternating with ifosfamide and etoposide) and local control. Peripheral-blood stem-cell collection was performed after the second cycle of chemotherapy, with delay if the bone marrow was persistently involved. If patients had a good response to initial therapy, they proceeded to consolidation therapy with melphalan, etoposide, TBI, and stem-cell support.

RESULTS

Of the 32 eligible patients, 23 proceeded to high-dose therapy consolidation. Of the nine patients who did not proceed to consolidation, four were secondary to progressive disease and two were secondary to toxicity. Three patients died from toxicity during the high-dose phase of the therapy. The majority of the patients who underwent high-dose consolidation therapy experienced relapse and died with progressive disease. Two-year event-free survival (EFS) for all eligible patients is 20%. The 2-year post-stem-cell reconstitution EFS for the subset of 23 patients who received consolidation therapy is 24%. Analysis of peripheral-blood stem-cell collections by molecular techniques for minimal residual disease showed contamination of at least some samples by tumor cells in all three patients with available data.

CONCLUSION

Consolidation with high-dose melphalan, etoposide, TBI, and autologous stem-cell support failed to improve the probability of EFS in this cohort of patients with newly diagnosed metastatic ES.

Molecular dynamics and (2)H-NMR study of the influence of an amphiphilic peptide on membrane order and dynamics

A molecular dynamics simulation of a fully hydrated model membrane consisting of 12 molecules of 1, 2-dimyristoyl-sn-glycero-3-phosphocholine, one amphiphilic peptide with the sequence acetyl-Lys-Lys-Gly-Leu(16)-Lys-Lys-Ala-amide, and 593 water molecules was performed for 1.06 ns (Belohorcova, K., J. H. Davis, T. B. Woolf, and B. Roux. 1997. Biophys. J. 73:3039-3055). The analysis presented here is primarily focused on the phospholipid component and the results are compared with experimental (2)H-NMR studies of the lipid component of mixtures of the same peptide and lipid at a molar ratio of 1:32, and with earlier studies of closely related peptide/lipid mixtures. The phospholipid chain and headgroup isomer populations and isomerization rates compare favorably with previous simulations and experimental measurements. Of particular interest is the effect of the peptide on the phospholipid headgroup and hydrocarbon chain orientational order calculated from the simulation, which also agree well with experimental measurements performed on this and closely related systems. Comparison of the experimental results with the simulations not only shows that there is significant agreement between the two methods, but also provides new insight into the effect of the peptide on the lipid dynamics. In particular, these results confirm that a membrane spanning peptide has little effect on lipid chain order, and bilayer thickness if its hydrophobic length closely matches the lipid hydrocarbon thickness. In addition, we find that the peptide can have a strong ordering effect if it is longer than the lipid hydrophobic thickness.

1H and (13)C NMR of multilamellar dispersions of polyunsaturated (22:6) phospholipids

The polyunsaturated fatty acid docosahexaenoic acid (DHA) makes up approximately 50% of the lipid chains in the retinal rod outer segment disk membranes and a large fraction of the lipid chains in the membranes of neuronal tissues. There is an extensive literature concerned with the dietary requirements for essential fatty acids and the importance of DHA to human health, but relatively little research has been done on the physical properties of this important molecule. Using (1)H and (13)C MAS NMR measurements of dispersions of 1-palmitoyl-2-docosahexaenoyl-phosphatidylcholine in excess phosphate buffer, we have unambiguously assigned most of the resonances in both the (1)H and (13)C NMR spectra. We were able to use cross-polarization spectroscopy to follow the transfer of polarization from specific (1)H nuclei not only to their directly bonded (13)C but also to those (13)C that are in close proximity, even though they are not directly bonded. Cross-peaks in two-dimensional cross-polarization spectra revealed a close association between the choline headgroup and at least part of the DHA chain but not with the palmitate chain. Finally, we examined the dynamics of the different parts of this lipid molecule, using rotating frame spin-lattice relaxation measurements, and found that methylene groups of both chains experience important motions with correlation times in the 10-micros range, with those for the palmitate chain being approximately 50% longer than those of the DHA chain. The choline headgroup and the chain terminal groups have significantly shorter correlation times, and that part of the dipolar interaction that is fluctuating at these correlation times is significantly smaller for these groups than it is for the palmitate and DHA chain methylenes.

Diamond-blackfan anemia and cyclosporine therapy revisited

A girl with Diamond-Blackfan anemia diagnosed in infancy started cyclosporine A (CSA) therapy at 9 years and 8 months of age after experiencing unacceptable side effects while receiving prednisone. Since then, she has been followed-up for more than 4 years. She exhibited a dramatic response to CSA, with weaning and then cessation of steroid therapy after 5 months. She has remained transfusion-independent. Attempts to discontinue CSA therapy have been unsuccessful. Relapse of the anemia has occurred in the context of viral infections with missed CSA doses. The major clinical problem during treatment has been recurrent oral aphthous ulceration, which responds to topical therapy. She is currently maintained on CSA 100 mg twice daily with a hemoglobin of 10.2 g/dL and a reticulocyte count of 1.6%. A trial of CSA therapy should be considered in patients with Diamond-Blackfan anemia in whom steroid therapy has failed before a transfusion program is instituted or alternative donor stem cell transplantation is entertained.

Assessing disaster-attributed mortality: development and application of a definition and classification matrix

BACKGROUND

A useful step in developing and implementing sound policies to prevent disaster-attributed mortality is to classify the relationship between disasters and mortality. While there are classification methods for specific health outcomes, there is no standard method that includes all potential outcomes from exposure to a natural disaster. Without standards, our ability to assess health effects from disasters and implement prevention programmes is limited.

METHODS

We present a method for ascertaining and classifying disaster-attributed mortality which includes a case definition, flow chart, and matrix. The matrix is used for coding, reporting, and evaluating information about manner, cause, and circumstance of disaster-attributed deaths and geographical location and time of the disaster. To illustrate its use, two readers determine and classify deaths attributed to Hurricane Andrew (1992, USA).

RESULTS

Of 322 deaths investigated by the Dade County Medical Examiner's Office, our readers showed 97% (313/322) agreement on case status and 83% (35/42) agreement on case classification.

CONCLUSIONS

Our definition allows for a liberal interpretation of what constitutes disaster-related circumstances and the conditions or diseases that might arise from these circumstances. The inclusion of the flow chart and matrix provides a framework for consistent case classification and reporting. It also provides information about relationships between exposures and health effects, thereby identifying prevention policy needs.

Drowning without aspiration: is this an appropriate diagnosis?

It has been reported that 10-15% of drowning victims do not aspirate water. We have revisited the original studies quoted to reach this conclusion and find it is without foundation. Sudden cardiac standstill is known to occur on land and, therefore, may also occur when the victim is in water. In the absence of the common finding of significant pulmonary edema in the victim's respiratory system, to conclude his or her death was caused by "drowning without aspiration" is unwise. All causes of sudden death that might occur in which respiration may not take place should receive serious consideration when examining bodies with such findings that are found in water.

Rural trauma: the challenge for the next decade

Improving the care of trauma patients in a rural environment requires that several important issues be addressed. First, a universal definition of what constitutes "rural" must be established. We propose that a combined effort of the Federal Government and the Committee on Trauma of the American College of Surgeons develop this definition. Second, data on rural trauma demographics and outcome must be collected in a national database. We propose that this database be incorporated in the "TRACS" database of the Committee on Trauma of the American College of Surgeons. Such a database will allow a "needs assessment analysis of existing care in rural environments and facilitate planning and implementation of efficient systems of care. Funding for the rural database should come from the federal government. Finally, increased public awareness of problems unique to rural trauma care is necessary. The rural trauma subcommittee of the ACSCOT should go from an ad hoc committee to a standing committee with the American College of Surgeons Committee on Trauma. We propose a national conference on rural trauma care hosted by the federal government for the purpose of addressing these issues and simultaneously increasing public awareness.

13C-13C rotational resonance in a transmembrane peptide: a comparison of the fluid and gel phases

A comparative study of two doubly 13C labeled amphiphilic transmembrane peptides was undertaken to determine the potential of rotational resonance for measuring internuclear distances through the direct dipolar coupling in the presence of motion. The two peptides, having the sequence acetyl-K2-G-L16-K2-A-amide, differed only in the position of 13C labels. The first peptide, [1-13C]leu(11):[alpha-13C]leu(12), had labels on adjacent residues, at the carbonyl of leu(11) and the alpha carbon of leu(12). The second, [1-13C]leu(8):[alpha-(13)/C]leu(11), was labeled on consecutive turns of the alpha-helical peptide. The internuclear distance between labeled positions of the first peptide, which for an ideal alpha helix has a value of 2.48 A, is relatively independent of internal flexibility or peptide conformational change. The dipolar coupling between these two nuclei is sensitive to motional averaging by molecular reorientation, however, making this peptide ideal for investigating these motions. The internuclear distance between labels on the second peptide has an expected static ideal alpha-helix value of 4.6 A, but this is sensitive to internal flexibility. In addition, the dipolar coupling between these two nuclei is much weaker because of their larger separation, making this peptide a much more difficult test of the rotational resonance technique. The dipolar couplings between the labeled nuclei of these two peptides were measured by rotational resonance in the dry peptide powders and in multilamellar dispersions with dimyristoylphosphatidylcholine in the gel phase, at -10 degrees C, and in the fluid phase, at 40 degrees C. The results for the peptide having adjacent labels can be readily interpreted in terms of a simple model for the peptide motion. The results for the second peptide show that, in the fluid phase, the motionally averaged dipolar coupling is too small to be measured by rotational resonance. Rotational resonance, rotational echo double resonance, and related techniques can be used to obtain reliable and valuable dipolar couplings in static solid and membrane systems. The interpretation of these couplings in terms of internuclear distances is straightforward in the absence of molecular motion. These techniques hold considerable promise for membrane protein structural studies under conditions, such as at low temperatures, where molecular motion does not modulate the dipolar couplings. However, a typical membrane at physiological temperatures exhibits complex molecular motions. In the absence of an accurate and detailed description of both internal and whole body molecular motions, it is unlikely that techniques of this type, which are based on extracting distances from direct internuclear dipolar couplings, can be used to study molecular structure under these conditions. Furthermore, the reduction in the strengths of the dipolar couplings by these motions dramatically reduces the useful range of distances which can be measured.

A flowsheet for documenting independent nursing visits after breast surgery

PURPOSE/OBJECTIVES

To redesign a postoperative flowsheet already used in clinical practice with patients who have undergone breast surgery to reflect documentation of assessments and interventions noted on each nursing visit.

DATA SOURCES

Memorial Sloan-Kettering Cancer Center Standards of Practice for Ambulatory Care, clinical experience, and published articles.

DATA SYNTHESIS

A comprehensive flowsheet was redesigned to provide consistency in documentation and reflect current needs of patients who have undergone breast surgery who are in ambulatory care.

CONCLUSIONS

Implementation of the new flowsheet has decreased staff documentation time during busy office practices and accurately reflects the nursing care provided to patients after breast surgery.

IMPLICATIONS FOR NURSING PRACTICE

Consistency in patient care can be maintained and efficiency can be increased with use of a comprehensive flowsheet.

In-vivo glutaraldehyde fixation of the brain stem and spinal cord after inadvertent intrathecal injection

A 64-year-old diabetic man underwent total maxillectomy with orbital exenteration because of recurrent carcinoma. In order to decrease pressure at the surgical site, 50 mL of cerebrospinal fluid were withdrawn. After the procedure was completed, 5% glutaraldehyde was inadvertently injected into the subarachnoid space instead of reinjection of the original cerebrospinal fluid. The patient suffered hypotension and coma culminating in death five days after the procedure. Postmortem examination revealed exquisite fixation of the outer cortical shell of the spinal cord and brain stem. The mishap occurred because an unlabeled vial was mistaken for the withdrawn cerebrospinal fluid. Graicunas' theory and formula on relationship complexities in organizations is exemplified by this occurrence. One may calculate the theoretical potential for 24,708 miscommunications during such a complex and lengthy surgical procedure. Proper operating room procedures must be developed and followed in order to prevent such tragedies.

Randomized trial of a patient-centered hospital unit

Patient-centered hospital units have grown out of the national trend to greater consumerism, but few of these units have been evaluated rigorously. We used a randomized controlled trial to compare patient outcomes on the Planetree Model Hospital Unit with other medical-surgical units in the hospital. Planetree patients were significantly more satisfied than controls with their hospital stay, the unit's environment and nursing care, but did not differ in ratings of physician care. Planetree patients reported more involvement in their care while hospitalized and higher satisfaction with the education they received. There were few differences between Planetree and controls in health behaviors. While Planetree patients reported better mental health status and role functioning after discharge, their health status was similar to controls after 3 to 6 months. There were no differences in length of stay and charges for the index hospitalization, readmissions or outpatient care during the following year.

Relationship between enzyme specificity and the backbone dynamics of free and inhibited alpha-lytic protease

To better understand the structural basis for the observed patterns in substrate specificity, the backbone dynamics of alpha-lytic protease have been investigated using 15N relaxation measurements. The enzyme was inhibited with the peptide boronic acid N-tert-butyloxycarbonyl-Ala-Pro-boroVal [Kettner, C. A., et al. (1988) Biochemistry 27, 7682], which mimics interactions occurring in the tetrahedral transition state or nearby intermediates, and the dynamics of the unbound and inhibited enzyme were compared. Arrayed 2-D NMR spectra were acquired to measure T1, T2, and steady-state ¿1H¿-15N NOE of >95% of the backbone amides in both protein samples. The overall rotational correlation time tauc was found to be 8.1 ns. Values of the spectral density function J(omega) at omega = 0, omegaN, and approximately omegaH were derived from the relaxation results using reduced spectral density mapping [Ishima, R., & Nagayama, K. (1995) Biochemistry 34, 3162]. The resultant spectral densities were interpreted to indicate regions of fast motion (nanosecond to picosecond) and of intermediate chemical exchange (millisecond to microsecond). The protein has 13 regions with increased motion on the fast time scale; these generally fall on exterior turns and loops and most correlate with regions of higher crystallographic B-factors. Several stretches of backbone undergo intermediate chemical exchange, indicating motion or other processes that cause temporal chemical shift changes. A comparison of spectral densities for both the free and inhibited enzymes revealed that inhibitor binding preferentially stabilizes regions undergoing chemical exchange (which predominate around the active site) and only minimally affect regions of rapid motion. Slow motions, suggestive of backbone plasticity, are observed in most of the binding pocket residues. This may point to a mechanism for the observed broad specificity of the enzyme. The significance of the observed dynamics for substrate binding and specificity is discussed.

Successful use of cyclosporine A in the treatment of refractory thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is, in most cases, treatable with plasma exchange therapy (PLEX). Rarely, patients do not respond to PLEX or develop refractory disease despite an initial remission. In these cases, treatment options are limited and the response to established alternative therapies is often disappointing. We report the case of a paediatric patient with TTP who developed refractory disease after an initial response to PLEX. She was subsequently treated with cyclosporine A and showed an immediate and sustained response. CSA may be a safe and effective therapy for patients with refractory TTP and should be studied in randomized, prospective clinical trials.

Homicide or suicide: the killing of suicidal persons by law enforcement officers

This paper presents 15 deaths of suicidal persons in Oregon and Florida who, by their behavior, sufficiently provoked law enforcement officers into killing them. Four deaths were certified as suicide, one as undetermined and ten as homicide. All of the deaths are individually described in detail and their case characteristics are presented in a table. The method of study is a descriptive analysis of the case characteristics, including 21 variables which are determined to be relevant to the classification of death. The variables were grouped into six categories: (a) personal information; (b) criminal behavior during the fatal incident; (c) dangerous behavior during the fatal incident; (d) toxicological data; (e) mental illness information; and (f) certification data. From the analysis, reasons for the opinions on manner of death classification are presented. All incidents were perceived as life-threatening to law officers, family members, or hostages. All victims were male except one, and all were Caucasian except two. All victims resisted arrest and verbally threatened homicide during the fatal incident. Two-thirds of the victims took hostages. All victims possessed an apparent handgun or other weapon (knife, iron bar). All victims posed their weapon and threatened others during the incident, 60% of victims actually used the weapon with apparent intent to inflict damage to others. 40% of victims were intoxicated with alcohol but other drug-involvement was uncommon. Seven of 15 had previous suicide attempts, 40% had medically documented psychiatric diagnoses and 60% had reasonable historical evidence of psychiatric diagnoses, most commonly depression or substance abuse. One of the co-authors presents the case for some of the deaths to be certified as suicides, whereas two present the case for all to be certified as homicide. A brief discussion of psychiatric issues is also presented concerning individuals who use others to commit suicide and who may engage in dangerous and/or criminal behavior to do so. A major conclusion is that there is lack of a unified opinion on death certification procedures for individuals who have provoked law enforcement officers to kill them. For such cases, it is recommended that professional organizations of medical examiners/coroners develop guidelines to promote consistency in death certification practices including manner of death classification and selection of death certificate wording so that "police-assisted suicide" may be appropriately reported and studied.

Structure and dynamics of an amphiphilic peptide in a lipid bilayer: a molecular dynamics study

A molecular dynamics simulation of a simple model membrane system composed of a single amphiphilic helical peptide (ace-K2GL16K2A-amide) in a fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine bilayer was performed for a total of 1060 ps. The secondary structure of the peptide and its stability were described in terms of average dihedral angles, phi and psi, and the C alpha torsion angles formed by backbone atoms; by the average translation per residue along the helix axis; and by the intramolecular peptide hydrogen bonds. The results indicated that residues 6 through 15 remain in a stable right-handed alpha-helical conformation, whereas both termini exhibit substantial fluctuations. A change in the backbone dihedral angles for residues 16 and 17 is accompanied by the loss of two intramolecular hydrogen bonds, leading to a local but long-lived disruption of the helix. The dynamics of the peptide was characterized in terms of local and global helix motions. The local motions of the N-H bond angles were described in terms of the autocorrelation functions of P2[cos thetaNH(t, t + tau)] and reflected the different degrees of local peptide order as well as a variation in time scale for local motions. The chi1 and chi2 dihedral angles of the leucine side chains underwent frequent transitions between potential minima. No connection between the side-chain positions and their mobility was observed, however. In contrast, the lysine side chains displayed little mobility during the simulation. The global peptide motions were characterized by the tilting and bending motions of the helix. Although the peptide was initially aligned parallel to the bilayer normal, during the simulation it was observed to tilt away from the normal, reaching an angle of approximately 25 degrees by the end of the simulation. In addition, a slight bend of the helix was detected. Finally, the solvation of the peptide backbone and side-chain atoms was also investigated.

Alterations in chemical shifts and exchange broadening upon peptide boronic acid inhibitor binding to alpha-lytic protease

alpha-Lytic protease, a bacterial serine protease of 198 amino acids (19 800 Da), has been used as a model system for studies of catalytic mechanism, structure-function relationships, and more recently for studies of pro region-assisted protein folding. We have assigned the backbones of the enzyme alone, and of its complex with the tetrahedral transition state mimic N-tert-butyloxycarbonyl-Ala-Pro-boro Val, using double- and triple-resonance 3D NMR spectroscopy on uniformly 15N- and 13C/15N-labeled protein. Changes in backbone chemical shifts between the uncomplexed and inhibited form of the protein are correlated with distance from the inhibitor, the displacement of backbone nitrogens, and change in hydrogen bond strength upon inhibitor binding (derived from previously solved crystal structures). A comparison of the solution secondary structure of the uninhibited enzyme with that of the X-ray structure reveals no significant differences. Significant line broadening, indicating intermediate chemical exchange, was observed in many of the active site amides (including three broadened to invisibility), and in a majority of cases the broadening was reversed upon addition of the inhibitor. Implications and possible mechanisms of this line broadening are discussed.