Virus-expressed, recombinant single-chain antibody blocks sporozoite infection of salivary glands in Plasmodium gallinaceum-infected Aedes aegypti

Transgenic mosquitoes resistant to malaria parasites are being developed to test the hypothesis that they may be used to control disease transmission. We have developed an effector portion of an antiparasite gene that can be used to test malaria resistance in transgenic mosquitoes. Mouse monoclonal antibodies that recognize the circumsporozoite protein of Plasmodium gallinaceum can block sporozoite invasion of Aedes aegypti salivary glands. An anti-circumsporozoite monoclonal antibody, N2H6D5, whose corresponding heavy- and light-chain gene variable regions were engineered as a single-chain antibody construct, binds to P. gallinaceum sporozoites and prevents infection of Ae. aegypti salivary glands when expressed from a Sindbis virus. Mean intensities of sporozoite infections of salivary glands in mosquitoes expressing N2scFv were reduced as much as 99.9% when compared to controls.

Heavy metals in wild rice from northern Wisconsin

Wild rice grain samples from various parts of the world have been found to have elevated concentrations of heavy metals, raising concern for potential effects on human health. It was hypothesized that wild rice from north-central Wisconsin could potentially have elevated concentrations of some heavy metals because of possible exposure to these elements from the atmosphere or from water and sediments. In addition, no studies of heavy metals in wild rice from Wisconsin had been performed, and a baseline study was needed for future comparisons. Wild rice plants were collected from four areas in Bayfield, Forest, Langlade, Oneida, Sawyer and Wood Counties in September, 1997 and 1998 and divided into four plant parts for elemental analyses: roots, stems, leaves and seeds. A total of 194 samples from 51 plants were analyzed across the localities, with an average of 49 samples per part depending on the element. Samples were cleaned of soil, wet digested, and analyzed by ICP for Ag, As, Cd, Cr, Cu, Hg, Mg, Pb, Se and Zn. Roots contained the highest concentrations of Ag, As, Cd, Cr, Hg, Pb, and Se. Copper was highest in both roots and seeds, while Zn was highest just in seeds. Magnesium was highest in leaves. Seed baseline ranges for the 10 elements were established using the 95% confidence intervals of the medians. Wild rice plants from northern Wisconsin had normal levels of the nutritional elements Cu, Mg and Zn in the seeds. Silver, Cd, Hg, Cr, and Se were very low in concentration or within normal limits for food plants. Arsenic and Pb, however, were elevated and could pose a problem for human health. The pathway for As, Hg and Pb to the plants could be atmospheric.

Unifying organizational approaches to measuring and managing patient outcomes

Information about patient outcomes is increasingly available to guide consumers in their selection of healthcare. By unifying the traditionally separate programs of performance improvement, case management, and research, nurse executives can take control of care processes and outcomes. This article provides four case examples of patient care improvements achieved using performance improvement, case management, and research approaches. The use of the technologies outlined in the Johnson and Nolan article in this issue, "A Guide to Choosing Technology to Support the Measurement of Patient Outcomes", also is described.

Direct detection of Borrelia burgdorferi in Ixodes scapularis (Acari: Ixodidae) nymphs by hybridization to ribosomal RNA

A method for direct detection of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner has been developed. Cells are lysed to facilitate release of ribosomal RNA. Lysates are filtered onto nylon membranes that are hybridized with probes specific for sequences in B. burgdorferi 23S rRNA. The technique is rapid and does not require any enzymatic amplification steps. With the use of a cocktail containing five different probes, approximately 1,000 organisms could be detected. The assay was successfully applied to direct detection of B. burgdorferi in Ixodes scapularis Say nymphs.

High levels of sequence polymorphism and linkage disequilibrium at the telomere of 12q: implications for telomere biology and human evolution

The human Xp/Yp telomere-junction region exhibits high levels of sequence polymorphism and linkage disequilibrium. To determine whether this is a general feature of human telomeres, we have undertaken sequence analysis at the 12q telomere and have extended the analysis at Xp/Yp. A total of 22 single-nucleotide polymorphisms (SNPs) and one 30-bp duplication were detected in the 1,870 bp adjacent to the 12q telomere. Twenty polymorphic positions were in almost complete linkage disequilibrium, creating three common diverged haplotypes accounting for 80% of 12q telomeres in the white population. A further 6% of 12q telomeres contained a 1,439-bp deletion in the DNA flanking the telomere. The remaining 13% of 12q telomeres did not amplify with the primers used (nulls). The distribution of telomere (TTAGGG) and variant repeats within 12q telomeres was hypervariable, but alleles with similar distribution patterns were associated with the same haplotype in the telomere-adjacent DNA. These data suggest that 12q telomeres, like Xp/Yp telomeres, exhibit low levels of homologous recombination and evolve along haploid lineages. In contrast, high levels of homologous recombination occur in the adjacent proterminal regions of human chromosomes. This suggests that there is a localized telomere-mediated suppression of recombination. In addition, the genetic characteristics of these regions may provide a source of deep lineages for the study of early human evolution, unaffected by both natural selection and recombination. To explain the presence of a few diverged haplotypes adjacent to the Xp/Yp and 12q telomeres, we propose a model that involves the hybridization of two archaic hominoid lineages ultimately giving rise to modern Homo sapiens.

Characterization of the self association of Avian sarcoma virus integrase by analytical ultracentrifugation

Retroviral integration protein (IN) has been shown to be both necessary and sufficient for the integration of reverse-transcribed retroviral DNA into the host cell DNA. It has been demonstrated that self-assembly of IN is essential for proper function. Analytical ultracentrifugation was used to determine the stoichiometry and free energy of self-association of a full-length IN in various solvents at 23.3 degrees C. Below 8% glycerol, an association stoichiometry of monomer-dimer-tetramer is observed. At salt concentrations above 500 mM, dimer is the dominant species over a wide range of protein concentrations. However, as physiological salt concentrations are approached, tetramer formation is favored. The addition of glycerol to 500 mM NaCl, 20 mM Tris (pH 8.4), 2 mM beta-mercaptoethanol significantly enhances dimer formation with little effect on tetramer formation. Furthermore, as electrostatic shielding is increased by increasing the ionic strength or decreasing the cation size, dimer formation is strengthened while tetramer formation is weakened. Taken together, the data support a model in which dimer formation includes favorable buried surface interactions which are opposed by charge-charge repulsion, while favorable electrostatic interactions contribute significantly to tetramer formation.

Bile duct injuries in laparoscopic cholecystectomy: nursing perspective

The advent of laparoscopic cholecystectomy brought a new approach with many advantages to patients for the treatment of symptomatic gallstones. What was not anticipated was an increase in bile duct injuries as a major complication of this new technique. The advanced practice nurse (APN) must understand the technical aspects of a laparoscopic cholecystectomy and routine perioperative care, because this knowledge provides a basis to recognize signs and symptoms of potential postoperative problems characteristic of a bile duct injury. The APN may be the initial healthcare provider who examines a patient or who is contacted by the patient with reports of symptoms that must be heeded and acted on. The APN responds to the patient by providing symptom management, initiating and coordinating care, and alerting the healthcare team. The APN at a specialty center may also be the consistent member of the healthcare team caring for a patient through nonoperative management and operative repair of the bile duct injury. Knowledge of the spectrum of bile duct injuries, their various manifestations, diagnostic tests, nonoperative management, and complex surgical repair is necessary for the APN to educate patients, coordinate care along the continuum, and support a patient with a bile duct injury. The medicolegal aspect of bile duct injury during laparoscopic cholecystectomy is also a topic the APN may encounter that requires thoughtful consideration and response. The recognition of subtle postoperative symptoms of a laparoscopic cholecystectomy may mean the difference between early diagnosis of and intervention in a minor injury or a major complication.

Implementing smoking policies within trusts: nurses' perceptions and views of effectiveness and implications

AIM

This study set out to explore nurses' views and perceptions of their hospital Trust's smoking policy, and the effects that it has had on both staff and patients.

BACKGROUND

Although soliciting and considering the views and perceptions of staff during smoking policy development increases the likelihood of effective implementation, such activity does not appear to be routinely undertaken within the NHS.

METHODS

Semistructured interviews were conducted with seven surgical nurses working within one district general hospital in the UK.

RESULTS

While all of the subjects acknowledged the value of there being a smoking policy, they felt that their Trust's policy placed nurses in a powerless and vulnerable position, with little support available to help effectively address the problems that smoking raised for them and their patients.

CONCLUSIONS

NHS Trusts that wish to develop and implement effective smoking policies should engage their staff throughout the process, and not underestimate the positive contribution that they all can make.

Three-dimensional ultrasonographic telepresence

We have developed a three-dimensional ultrasound telepresence system for remote consultation. Three-dimensional ultrasound data-sets can be acquired by relatively unskilled operators. The data are stored in the remote unit and then transmitted to a consultant equipped with a similar unit. A telepresence pointing device enables the consultant to re-slice that data-set in any plane. During the study period, 72 volumetric scans of male and female volunteers aged 18-45 years were performed in Bosnia. Field users of limited ultrasound experience (most with less than 30 min of training) were able to acquire volumetric scans, send volume data and interact with remote consultants over standard communications lines at distances of up to 20,000 km. Communications links from 9.6 to 1500 kbit/s were used. Technical limitations included lack of motion data, lack of colour data, scan artefacts and increased scan-to-diagnosis time. However, our preliminary experience indicates that this technique may eventually prove to be a useful adjunct to telesonography. Further studies of the technique are needed to determine its value in the broader clinical setting.

Outpatient laparoscopic cholecystectomy: patient and nursing perspective

Outpatient laparoscopic cholecystectomy has become nearly mandatory in the current health care economic environment. This study determined the opinions of patients and their nurses regarding disability and pain after laparoscopic cholecystectomy. Using a 14-point questionnaire, 32 consecutive patients who underwent inpatient LC were surveyed. The nurses caring for these patients were surveyed with a nine-point questionnaire. Seventy-one percent of patients believed that they could not have been discharged the day of surgery; the nurses reported that 81% of the patients could not have gone home. Nausea and vomiting were common. Pain was rated as 9 or 10 in 19% of patients. Nurses reported that 56% of postoperative patients were not receptive to discharge teaching. Morning (16) versus afternoon (16) procedures were not different. Successful programs of outpatient LC must: 1) ensure adequate home support because patient capability will be limited, 2) optimize pain control, 3) minimize nausea and vomiting, and 4) deliver patient education preoperatively.

Clinical pathway implementation improves outcomes for complex biliary surgery

BACKGROUND

Complex biliary surgery is associated with significant morbidity, prolonged hospital stay, and high cost. Clinical pathway implementation has the potential to standardize treatment and improve outcomes. Therefore the aim of this analysis was to determine whether clinical pathway implementation and/or feedback of outcome data would alter hospital stay, charges, and mortality rates for complex biliary surgery at an academic medical center

METHODS

Pre- and postoperative length of stay, hospital charges, and mortality rates were monitored for 36 months before (period 1) and for 2 18-month periods (periods 2 and 3) after implementation of a clinical pathway for hepaticojejunostomy. Outcome data were provided to the surgeons 18 months after pathway implementation to determine whether further clinical practice improvement was possible.

RESULTS

From 1991 to 1997, 339 patients underwent hepaticojejunostomy at The Johns Hopkins Hospital for malignant and benign biliary obstruction. Total length of stay was 13.3 +/- 0.9 days for period 1 compared with 12.5 +/- 0.8 days for period 2 (not significant) and 10.1 +/- 0.3 days for period 3 (P < .01 vs period 1; P < .03 vs period 2). Hospital charges averaged $24,446 during period 1 compared with $23,338 during period 2 and $20,240 during period 3 (P < .01 vs periods 1 and 2). Hospital mortality rate was 4.5% during period 1 compared with 0.7% during periods 2 and 3 (P < .05).

CONCLUSIONS

These data suggest that implementation of a clinical pathway for hepaticojejunostomy reduces hospital mortality rates and that feedback of outcome data to surgeons results in further clinical practice improvement. Thus clinical pathway implementation and feedback are effective methods to control costs at an academic medical center.

Is prophylactic gastrojejunostomy indicated for unresectable periampullary cancer? A prospective randomized trial

OBJECTIVE

This prospective, randomized, single-institution trial was designed to evaluate the role of prophylactic gastrojejunostomy in patients found at exploratory laparotomy to have unresectable periampullary carcinoma.

SUMMARY BACKGROUND DATA

Between 25% and 75% of patients with periampullary cancer who undergo exploratory surgery with intent to perform a pancreaticoduodenectomy are found to have unresectable disease. Most will undergo a biliary-enteric bypass. Whether or not to perform a prophylactic gastrojejunostomy remains unresolved. Retrospective reviews of surgical series and prospective randomized trials of endoscopic palliation have demonstrated that late gastric outlet obstruction, requiring a gastrojejunostomy, develops in 10% to 20% of patients with unresectable periampullary cancer.

METHODS

Between May 1994 and October 1998, 194 patients with a periampullary malignancy underwent exploratory surgery with the purpose of performing a pancreaticoduodenectomy and were found to have unresectable disease. On the basis of preoperative symptoms, radiologic studies, or surgical findings, the surgeon determined that gastric outlet obstruction was a significant risk in 107 and performed a gastrojejunostomy. The remaining 87 patients were thought by the surgeon not to be at significant risk for duodenal obstruction and were randomized to receive either a prophylactic retrocolic gastrojejunostomy or no gastrojejunostomy. Short- and long-term outcomes were determined in all patients.

RESULTS

Of the 87 patients randomized, 44 patients underwent a retrocolic gastrojejunostomy and 43 did not undergo a gastric bypass. The two groups were similar with respect to age, gender, procedure performed (excluding gastrojejunostomy), and surgical findings. There were no postoperative deaths in either group, and the postoperative morbidity rates were comparable (gastrojejunostomy 32%, no gastrojejunostomy 33%). The postoperative length of stay was 8.5+/-0.5 days for the gastrojejunostomy group and 8.0+/-0.5 days for the no gastrojejunostomy group. Mean survival among those who received a prophylactic gastrojejunostomy was 8.3 months, and during that interval gastric outlet obstruction developed in none of the 44 patients. Mean survival among those who did not have a prophylactic gastrojejunostomy was 8.3 months. In 8 of those 43 patients (19%), late gastric outlet obstruction developed, requiring therapeutic intervention (gastrojejunostomy 7 patients, endoscopic duodenal stent 1 patient; p < 0.01). The median time between initial exploration and therapeutic intervention was 2 months.

CONCLUSION

The results from this prospective, randomized trial demonstrate that prophylactic gastrojejunostomy significantly decreases the incidence of late gastric outlet obstruction. The performance of a prophylactic retrocolic gastrojejunostomy at the initial surgical procedure does not increase the incidence of postoperative complications or extend the length of stay. A retrocolic gastrojejunostomy should be performed routinely when a patient is undergoing surgical palliation for unresectable periampullary carcinoma.

Controlling malaria transmission with genetically-engineered, Plasmodium-resistant mosquitoes: milestones in a model system

We are developing transgenic mosquitoes resistant to malaria parasites to test the hypothesis that genetically-engineered mosquitoes can be used to block the transmission of the parasites. We are developing and testing many of the necessary methodologies with the avian malaria parasite, Plasmodium gallinaceum, and its laboratory vector, Aedes aegypti, in anticipation of engaging the technical challenges presented by the malaria parasite, P. falciparum, and its major African vector, Anopheles gambiae. Transformation technology will be used to insert into the mosquito a synthetic gene for resistance to P. gallinaceum. The resistance gene will consist of a promoter of a mosquito gene controlling the expression of an effector protein that interferes with parasite development and/or infectivity. Mosquito genes whose promoter sequences are capable of sex- and tissue-specific expression of exogenous coding sequences have been identified, and stable transformation of the mosquito has been developed. We now are developing the expressed effector portion of the synthetic gene that will interfere with the transmission of the parasites. Mouse monoclonal antibodies that recognize the circumsporozoite protein of P. gallinaceum block sporozoite invasion of mosquito salivary glands, as well as abrogate the infectivity of sporozoites to a vertebrate host, the chicken, Gallus gallus, and block sporozoite invasion and development in susceptible cell lines in vitro. Using the genes encoding these antibodies, we propose to clone and express single-chain antibody constructs (scFv) that will serve as the effector portion of the gene that interferes with transmission of P. gallinaceum sporozoites.

The plasticity of human telomeres demonstrated by a hypervariable telomere repeat array that is located on some copies of 16p and 16q

Human telomeres are composed of tandem arrays of TTAGGG repeats with many variant repeats at the proximal ends. Comparison of the interspersion of variant and TTAGGG repeats between alleles can be used to study telomere instability, but the difficulty in identifying chromosome-specific sequences close to the start of autosomal telomeres has hampered such investigations. A chromosome end, including a telomere and adjacent sequence, that is polymorphic for its presence or absence in unrelated individuals has been identified. The telomere-adjacent DNA shows strong homology (92-99%) to sequences, including two expressed sequence tags, that are usually located in subterminal regions of human chromosomes but not adjacent to telomeres. Since this chromosome end arose, it has relocated at least once. In Caucasians, it forms the telomere of approximately 6% of 16q and 2% of 16p chromosome arms. The mechanism of relocation is unknown but must have involved the telomere-adjacent DNA rather than the telomere itself, as copies on 16p and 16q share the same telomere-adjacent sequence. The interspersion patterns of TTAGGG with TGAGGG, TTGGGG and non-amplifying repeat sequences revealed extensive allelic variation, such that 47 different alleles were observed among the 50 alleles mapped. Closely related alleles differ by small changes in copy number at blocks of adjacent like repeats, as seen at the Xp/Yp pseudoautosomal telomere. Such differences are compatible with a model in which the majority of mutations arise by intra-allelic mechanisms, in individuals hemizygous for a single copy of the chromosome end.

Multiple lysophosphatidic acid acyltransferases in Neisseria meningitidis

Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are critical phospholipid intermediates in the biosynthesis of cell membranes. In Escherichia coli, LPA acyltransferase (1-acyl-sn-glycerol-3-phosphate acyltransferase; EC 2.3.1.51) catalyses the transfer of an acyl chain from either acyl-coenzyme A or acyl-acyl carrier protein onto LPA to produce PA. While E. coli possesses one essential LPA acyltransferase (PlsC), Neisseria meningitidis possesses at least two LPA acyltransferases. This study describes the identification and characterization of nlaB (neisserial LPA acyltransferase B), the second LPA acyltransferase identified in N. meningitidis. The gene was located downstream of the Tn916 insertion in N. meningitidis mutant 469 and differed in nucleotide and predicted amino acid sequence from the previously characterized neisserial LPA acyltransferase homologue nlaA. NlaB has specific LPA acyltransferase activity, as demonstrated by complementation of an E. coli plsC(Ts) mutant in trans, by decreased levels of LPA acyltransferase activity in nlaB mutants and by lack of complementation of E. coli plsB26,X50, a mutant defective in the first acyltransferase step in phospholipid biosynthesis. Meningococcal nlaA mutants accumulated LPA and demonstrated alterations in membrane phospholipid composition, yet retained LPA acyltransferase activity. In contrast, meningococcal nlaB mutants exhibited decreased LPA acyltransferase activity, but did not accumulate LPA or display any other observable membrane changes. We propose that N. meningitidis possesses at least two LPA acyltransferases to provide for the production of a greater diversity of membrane phospholipids.

Pancreaticoduodenectomy with or without extended retroperitoneal lymphadenectomy for periampullary adenocarcinoma: comparison of morbidity and mortality and short-term outcome

OBJECTIVE

This prospective, randomized, single-institution trial was designed to evaluate the end points of mortality, morbidity, and survival in patients undergoing standard versus radical (extended) pancreaticoduodenectomy (including distal gastrectomy and retroperitoneal lymphadenectomy).

SUMMARY BACKGROUND DATA

Numerous retrospective reports and one prospective randomized trial have suggested that the performance of an extended lymphadenectomy in association with a pancreaticoduodenal resection may improve long-term survival for some patients with pancreatic and other periampullary adenocarcinomas. Many of these previously published studies can be criticized for their retrospective and nonrandomized designs, for the inclusion of nonconcurrent control groups, and for their small numbers.

METHODS

Between April 1996 and December 1997, 114 patients with periampullary adenocarcinoma were enrolled in an ongoing, prospective, randomized trial at The Johns Hopkins Hospital. After intraoperative verification of completely resected periampullary adenocarcinoma, the patients were randomized to receive either a standard pancreaticoduodenectomy (removing only the peripancreatic lymph nodes en bloc with the specimen) or a radical pancreaticoduodenectomy (standard resection plus distal gastrectomy and retroperitoneal lymphadenectomy). All pathology specimens were reviewed and categorized. The postoperative morbidity, mortality, and short-term outcomes were examined.

RESULTS

Of the 114 patients randomized, 56 underwent a standard pancreaticoduodenectomy and 58 a radical pancreaticoduodenectomy. The two groups were statistically similar with regard to age and gender, but there was a higher percentage of white patients in the radical group. All the patients in the radical group underwent distal gastric resection, whereas 86% of the patients in the standard group underwent pylorus preservation. The mean operative time in the radical group was 6.8 hours, compared with 6.2 hours in the standard group. There were no significant differences between the two groups with respect to the intraoperative blood loss, transfusion requirements, location of primary tumor, mean tumor size, positive lymph node status, or positive margin status. There were three deaths in the standard group and two in the radical group. The complication rates were 34% for the standard group and 40% for the radical group. Patients undergoing radical resection had a higher incidence of early delayed gastric emptying but had similar rates of other complications, such as pancreatic fistula, wound infection, intraabdominal abscess, and need for reoperation. The mean total number of lymph nodes resected was higher in the radical group. Of the 58 patients in the radical group, only 10% had metastatic carcinoma in the resected retroperitoneal lymph nodes, and none of those patients had the retroperitoneal nodes as the only site of lymph node involvement. The 1-year actuarial survival rate for patients surviving the immediate postoperative periods was 77% for the standard resection group and 83% for the radical resection group.

CONCLUSIONS

These data demonstrate that radical pancreaticoduodenectomy (with the addition of a distal gastrectomy and extended retroperitoneal lymphadenectomy to a standard pancreaticoduodenectomy) can be performed with similar morbidity and mortality to standard pancreaticoduodenectomy. However, the survival data are not sufficiently mature and the numbers of patients enrolled are not adequate to allow firm conclusions to be drawn regarding survival benefit.

Oral and maxillofacial surgery for the management of obstructive sleep apnea syndrome

The initial reports of treating obstructive sleep apnea using the uvulopalatopharyngoplasty were encouraging; however, as further trials of this procedure were reported, it began to show disappointing results. It was found that the retropalatal airway was not the only site of obstruction and procedures would need to be developed that would address obstruction in the other portions of the airway involved, notably in the retrolingual or hypopharyngeal portion of the airway. It was first reported by oral surgeons that mandibular surgery could also improve sleep apnea and through their work and the work of others, techniques have been developed using skeletal surgery to enhance the patency of the airway during sleep. This article describes some of these techniques and their indications, complications, and results.

Overview of sleep disorders: where does obstructive sleep apnea syndrome fit in?

Otolaryngologists deal primarily with the disorders of obstructive sleep apnea and primary snoring. It is important to realize that although these two disorders are common in the general population, they make up only a small segment of the entire field of sleep disorders medicine. This article attempts to introduce the otolaryngologist to the complexity of this field, help to gain respect and understanding of those practitioners dealing with this entire field, and learn why there is such a broad appeal of this field of medicine to so many subspecialists. Also presented are a table describing the classification of sleep disorders and a short tribute to those individuals who founded this relatively new field of medicine.

Sleep studies. Current techniques and future trends

Diagnosis of obstructive sleep apnea has been termed a laboratory diagnosis rather than a clinical diagnosis because one may not be able to make the diagnosis based on the history and physical examination alone. The polysomnogram was developed to give clinicians and researchers objective data on physiologic events occurring during the patient's sleep. From this, obstructive breathing patterns can be diagnosed and if pathologic, appropriate treatment can be instituted. Although the polysomnogram has been the gold standard for diagnosis for more than two decades, it is an expensive and time-consuming procedure. Current technologies for polysomnogram are reviewed, as well as proposals for alternatives that may be more cost and time effective.

Disordered breathing during sleep in newborns, infants, and children. Symptoms, diagnosis, and treatment

Although the polysomnographic findings of sleep-disordered breathing in children are similar to those in adults, the underlying causes will vary significantly from adults, depending on whether one is dealing with a newborn, infant, or child. How they react to the disease process is also at times different than seen in the adult and subsequent testing and treatment will also vary considerably. These differences and similarities are reviewed in this article.

Complications of snoring, upper airway resistance syndrome, and obstructive sleep apnea syndrome in adults

The complications of sleep-disordered breathing can be separated into two categories. First are those disorders that primarily are brought on by the sleep disorder itself. The second category is those pre-existing medical problems that are aggravated by the sleep disorder. This article examines the consequences of obstructive breathing disorders during sleep and reviews some of the current theories as to the pathophysiology of those problems directly resulting from the sleep disorder.

Oropharyngeal surgery in the management of upper airway obstruction during sleep

In the surgical management of snoring and sleep apnea, surgery to the oropharynx was the initial procedure used to treat sleep-related disorders. This article reviews both the various procedures available for this and the benefits and drawbacks of these procedures so the practitioner may be able to choose which type would be most beneficial for a particular patient.

Suspension sutures for the treatment of obstructive sleep apnea and snoring

Treatment of airway collapse in the retrolingual airway for obstructive sleep apnea syndrome and snoring has been a frequently frustrating exercise. There are several procedures that have been used with varying degrees of success for some time. These procedures include genioglossus advancement and hyoid suspension, as well as various forms of lingual plasty and lingual reduction. A new technique was introduced at the 1998 meeting of the American Academy of Otolaryngology-Head and Neck Surgery in San Antonio that consisted of using a suspension screw to support the hypopharyngeal soft tissues, specifically, the base of the tongue, to prevent its posterior displacement during sleep. Some of the initial results of these studies have been promising and are reviewed here.

Pancreatic cancer: a continuum of care

OBJECTIVES

To provide information about the etiology, clinical manifestations, treatment, and symptom management of pancreatic cancer.

DATA SOURCES

Textbook chapters, research studies, and review articles.

CONCLUSIONS

Cancer of the pancreas is a devastating disease. A diagnosis of pancreatic cancer causes a person to consider both quantity as well as quality of life. Hope for improved quality of life and survival relies on the efforts of a co-operative multidisciplinary team approach.

IMPLICATIONS FOR NURSING PRACTICE

Numerous nursing challenges exist in providing care for the patient with pancreatic cancer. Treatment, symptom management, and psychological, social, and spiritual support are essential in meeting the needs of the patient and family through the eventuality of the disease.

Balanced biosynthesis of major membrane components through regulated degradation of the committed enzyme of lipid A biosynthesis by the AAA protease FtsH (HflB) in Escherichia coli

The suppressor mutation, named sfhC21, that allows Escherichia coli ftsH null mutant cells to survive was found to be an allele of fabZ encoding R-3-hydroxyacyl-ACP dehydrase, involved in a key step of fatty acid biosynthesis, and appears to upregulate the dehydrase. The ftsH1(Ts) mutation increased the amount of lipopolysaccharide at 42 degrees C. This was accompanied by a dramatic increase in the amount of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase [the IpxC (envA) gene product] involved in the committed step of lipid A biosynthesis. Pulse-chase experiments and in vitro assays with purified components showed that FtsH, the AAA-type membrane-bound metalloprotease, degrades the deacetylase. Genetic evidence also indicated that the FtsH protease activity for the deacetylase might be affected when acyl-ACP pools were altered. The biosynthesis of phospholipids and the lipid A moiety of lipopolysaccharide, both of which derive their fatty acyl chains from the same R-3-hydroxyacyl-ACP pool, is regulated by FtsH.

The heart rate-corrected QT interval of conscious beagle dogs: a formula based on analysis of covariance

Three frequently used and cited formulas used to rate correct the QT interval (Bazett's, Fridericia's, and Van de Water's) were compared and ranked using a large population-based cohort of beagle dogs (99 males and 99 females). In addition, analysis of covariance was used to derive a flexible method to rate correct the QT.interval for heart rate. The method is flexible in that it utilizes pretest or control data to determine the degree of correction. In addition, it can also be used to evaluate whether treatment alters the association between heart rate and QT. Specifically, pretest QT (unadjusted) and heart rate data were used to estimate coefficients in the linear regression log(QT) = alpha + beta log(HR). The estimated slope (beta) from the pretest data was used to heart rate correct the QT interval in the formula log(QT)ca = log(QT) - beta *[log(HR - log(HRm)]. The term "log(HRm)" is included to standardize QTca to a reference value, either a fixed value or an average heart rate for the data set being analyzed. These formulas were retrospectively compared under a typical toxicity study paradigm with a class III antiarrhythmic agent (L-768,673) that selectively prolongs the QT interval by blocking the slow activating component of the delayed rectifying potassium channel (lks). Based on their ability to dissociate the effects of heart rate on the QT interval, the formulas received the following ranking: Covariate Adjustment (preferred) = Van De Water's > Fridericia's > Bazett's (not recommended). Analysis of covariance based on pretest or control data is preferred for moderate to large studies where there are adequate data for estimation of the slope parameter beta, the investigator does not have sufficient control over HR, or treatment alters the association between HR and the QT interval. Conversely, for smaller studies a fixed rate adjustment formula from the literature (such as Van de Water's or Fridericia's equations) may be preferable since the bias from using a fixed formula is likely to be smaller than the variance resulting from estimating beta from a small sample.

Use of a free bladder mucosal graft for simple repair of vesicovaginal fistulae

The aim of this paper is to describe a simple, fast, and effective method for repair of difficult vesicovaginal fistulae by means of a free bladder mucosal graft. Six patients with high, large, multiple, or recurrent vesicovaginal fistulae were treated using a free bladder mucosal graft. Three patients underwent "early" repair (less than 3 months from time of injury) and 3 "late" repair (more than 6 months from time of injury). Via a suprapubic cystotomy, the mucosa of the fistulous tract was debrided without any attempt to excise the tract or close the bladder or vaginal defects. A free bladder mucosal graft was harvested from an unaffected portion of the bladder and placed over the fistulous tract, and mucosal approximation was made using interrupted 5-0 chromic stay sutures. The donor urothelial defect was allowed to re-epithelialize. A Foley catheter, suprapubic tube, and vaginal packing were left in place. Five patients noted an immediate result, with no evidence of leakage, and the suprapubic tube was removed by week 3. One patient required prolonged catheter drainage, and the tube was successfully removed by week 6. This patient had undergone irradiation. All patients remain dry at follow-up, which ranges from 2 to 6 years. We describe a simple and effective method for transabdominal vesicovaginal fistula repair, involving minimal mobilization, decreased dissection, and no need for rotational or interposition flaps, obviating the need to open the peritoneum. A free bladder mucosal graft can be used regardless of the individual anatomy or proximity to the ureteral orifices, because it can easily be tailored. This technique represents an important repair of difficult, recurrent, or multiple vesicovaginal fistulae.

Should pancreaticoduodenectomy be performed in octogenarians?

As the population in the United States ages, an increasing number of elderly patients may be considered for pancreaticoduodenal resection. This high-volume, single-institution experience examines the morbidity, mortality, and long-term survival of 727 patients undergoing pancreaticoduodenectomy between December 1986 and June 1996. Outcomes of patients 80 years of age and older (n = 46) were compared to those of patients younger than 80 years. In these older patients, pancreaticoduodenectomy was performed for pancreatic adenocarcinoma (n = 25; 54%), ampullary adenocarcinoma (n = 9; 20%) distal bile duct adenocarcinoma (n = 5; 11%), duodenal adenocarcinoma (n = 2; 4%), cystadenocarcinoma; (n = 2; 4%), cystadenoma (n = 1; 2%), and chronic pancreatitis (n = 2; 4%). When compared to the 681 concurrent patients younger than 80 years who were undergoing pancreaticoduodenectomy, the two groups were statistically similar with respect to sex, race, intraoperative blood loss, and type of pancreaticoduodenectomy performed. Patients 80 years of age or older had a shorter median operative time (6.4 hours vs. 7.0 hours; P = 0.02) but a longer postoperative length of stay (median = 15 days vs. 13 days; P = 0.01) and a higher complication rate (57% vs. 41%; P = 0.05) when compared to their younger counterparts. Pancreaticoduodenectomy in the older group resulted in a 4.3% perioperative mortality rate compared to 1.6% in the younger group (P = NS). In the subset of patients undergoing pancreaticoduodenectomy for periampullary adenocarcinoma (n = 495), patients 80 years of age or older (n = 41) had a median survival of 32 months and a 5-year survival rate of 19%, compared to 20 months and 27%, respectively, in patients younger than 80 years (n = 454; P = 0.77). These data demonstrate that pancreaticoduodenectomy can be performed safely in selected patients 80 years of age or older, with morbidity and mortality rates approaching those observed in younger patients. Based on these data, age alone should not be a contraindication to pancreaticoduodenectomy.

Primary sclerosing cholangitis: resect, dilate, or transplant?

OBJECTIVE

The current study examines the results of extrahepatic biliary resection, nonoperative endoscopic biliary dilation with or without percutaneous stenting, and liver transplantation in the management of patients with primary sclerosing cholangitis (PSC).

SUMMARY BACKGROUND DATA

Primary sclerosing cholangitis is a progressive inflammatory disease leading to secondary biliary cirrhosis. The most effective management of sclerosing cholangitis before the onset of cirrhosis remains unclear.

METHODS

From 1980 to 1994, 146 patients with PSC were managed with either resection of the extrahepatic bile ducts and long-term transhepatic stenting (50 patients), nonoperative endoscopic biliary dilation with or without percutaneous stenting (54 patients), medical therapy (28 patients), and/or liver transplantation (21 patients).

RESULTS

Procedure-related morbidity and mortality rates were similar between surgically resected and nonoperatively managed patients. In noncirrhotic patients, the serum bilirubin level was significantly (p < 0.05) reduced from preoperative levels (8.3+/-1.5 mg/dL) 1 (1.7+/-0.4 mg/dL) and 3 (2.7+/-0.9 mg/ dL) years after resection, but not after endoscopic or percutaneous management. For noncirrhotic PSC patients, overall 5-year survival (85% vs. 59%) and survival until death or transplantation (82% vs. 46%) were significantly longer (p < 0.05) after resection than after nonoperative dilation with or without stenting. For cirrhotic patients, survival after liver transplantation was longer than after resection or nonoperative dilation with or without stenting. Five patients developed cholangiocarcinoma, including three (6%) of the nonoperatively managed patients but none of the resected patients.

CONCLUSIONS

In carefully selected noncirrhotic patients with PSC, resection and long-term stenting remains a good option. Patients with cirrhosis should undergo liver transplantation.

The methionine-rich low-molecular-weight chloroplast heat-shock protein: evolutionary conservation and accumulation in relation to thermotolerance

The evolutionary conservation of the low-molecular-weight chloroplast-localized heat-shock protein (LMW chlpHsp) in vascular plants was examined using immunological methods. An antibody (Abmet) specific to the LMW chlpHsp was produced using a synthetic 28-residue peptide containing the most conserved elements of its unique "methionine-rich domain" as an antigen. This antibody detected a heat-inducible low-molecular-weight chloroplast protein in plants of six divergent Anthophyta species, including C3, C4, CAM, monocot, and dicot species. Abmet also detected a LMW chlpHsp in species from the Divisions Psilotophyta, Equisetophyta, Polypodiophyta, and Ginkgophyta. A preliminary examination of the relationship between accumulation of the LMW chlpHsp and habitat was also conducted. Seven Anthophyta species originating from both warm- and cool-temperature habitats were grown at 28C and then heat stressed at 40C. A positive qualitative relationship between the accumulation of the LMW chlpHsp and organismal thermotolerance in these species was observed; similar results were obtained separately with four nonAnthophyta species. The strong evolutionary conservation of this LMW Hsp and its localization to the chloroplast, and the correlation between production of this protein and plant thermotolerance, suggest that the LMW chlpHsp plays an important role in adaptation to heat stress.

Reconstruction of partial laryngopharyngectomy defects

As our contributors to this section have pointed out, there are at present two main methods of reconstructing defects of the pharynx and cervical esophagus: free jejunal transfer (FJT) and tubed radial forearm flap. The advantage of the FJT is that it is a tube, thus limiting the enteric suture lines to proximal and distal. The radial forearm flap requires not only the proximal and distal suture lines but a long longitudinal suture line to create the tube. This increase the possibility for fistula formation. The controversy surrounding this case concerns what to do with a remaining mucosal strip after a subtotal laryngectomy. Traditional reconstructive principles would dictate that normal tissue should not be sacrificed, but some would argue that the remaining mucosa should be sacrificed to allow for use of a FJT. The other alternative would be use of a radical forearm skin flap tubed to 270 degrees. At the University of Texas M. D. Anderson Cancer Center, we preferentially use the FJT for almost all defects and would probably have sacrificed the remaining mucosal strip in this particular case. We have used skin flaps to patch pharyngeal defects and prevent stricture in a number of cases. This is usually done however when the remaining pharyngeal mucosa approaches 50% or greater. Although we do not routinely use the tubed radial forearm flap because of the increased rate of fistula formation, there are some definite indications for its use. The first important indication is in patients in whom speech rehabilitation is desired or indicated. The skin flap provides a stiffer resonating chamber for the speech production and does not have the peristalsis or the mucus production associated with the jejunal flap. Another indication for use of radial forearm flap would be when there is a contraindication to celiotomy, ie, patients with hepatic cirrhosis and associated ascites or other abdominal conditions precluding abdominal exploration. In this situation, avoiding an intra-abdominal procedure would limit operative morbidity. In conclusion, one should use whichever procedure obtains a healed wound and re-establishes continuity of the upper gastrointestinal tract. In our hands, retention of the remaining mucosal segment would not be critical in this particular case and in fact would present a hindrance to use of the FJT.

Six hundred fifty consecutive pancreaticoduodenectomies in the 1990s: pathology, complications, and outcomes

OBJECTIVE

The authors reviewed the pathology, complications, and outcomes in a consecutive group of 650 patients undergoing pancreaticoduodenectomy in the 1990s.

SUMMARY BACKGROUND DATA

Pancreaticoduodenectomy has been used increasingly in recent years to resect a variety of malignant and benign diseases of the pancreas and periampullary region.

METHODS

Between January 1990 and July 1996, inclusive, 650 patients underwent pancreaticoduodenal resection at The Johns Hopkins Hospital. Data were recorded prospectively on all patients. All pathology specimens were reviewed and categorized. Statistical analyses were performed using both univariate and multivariate models.

RESULTS

The patients had a mean age of 63 +/- 12.8 years, with 54% male and 91% white. The number of resections per year rose from 60 in 1990 to 161 in 1995. Pathologic examination results showed pancreatic cancer (n = 282; 43%), ampullary cancer (n = 70; 11%), distal common bile duct cancer (n = 65; 10%), duodenal cancer (n = 26; 4%), chronic pancreatitis (n = 71; 11%), neuroendocrine tumor (n = 31; 5%), periampullary adenoma (n = 21; 3%), cystadenocarcinoma (n = 14; 2%), cystadenoma (n = 25; 4%), and other (n = 45; 7%). The surgical procedure involved pylorus preservation in 82%, partial pancreatectomy in 95%, and portal or superior mesenteric venous resection in 4%. Pancreatic-enteric reconstruction, when appropriate, was via pancreaticojejunostomy in 71% and pancreaticogastrostomy in 29%. The median intraoperative blood loss was 625 mL, median units of red cells transfused was zero, and the median operative time was 7 hours. During this period, 190 consecutive pancreaticoduodenectomies were performed without a mortality. Nine deaths occurred in-hospital or within 30 days of operation (1.4% operative mortality). The postoperative complication rate was 41%, with the most common complications being early delayed gastric emptying (19%), pancreatic fistula (14%), and wound infection (10%). Twenty-three patients required reoperation in the immediate postoperative period (3.5%), most commonly for bleeding, abscess, or dehiscence. The median postoperative length of stay was 13 days. A multivariate analysis of the 443 patients with periampullary adenocarcinoma indicated that the most powerful independent predictors favoring long-term survival included a pathologic diagnosis of duodenal adenocarcinoma, tumor diameter <3 cm, negative resection margins, absence of lymph node metastases, well-differentiated histology, and no reoperation.

CONCLUSIONS

This single institution, high-volume experience indicates that pancreaticoduodenectomy can be performed safely for a variety of malignant and benign disorders of the pancreas and periampullary region. Overall survival is determined largely by the pathology within the resection specimen.

Acquired immunodeficiency syndrome in Alabama: special concerns for black women

BACKGROUND

Among AIDS case reports from rural and small town areas of the United States, rates are higher in the South than in any other part of the country.

METHODS

For this study, we analyzed AIDS surveillance statistics from the state of Alabama for trends, distributions, and populations affected. We aggregated Alabama AIDS surveillance data in 5-year intervals--1981 to 1985, 1986 to 1990, 1991 to 1995--and made comparisons based on geographic area of residence of people diagnosed with AIDS.

RESULTS

Of the 3,558 cases of AIDS reported in Alabama in the period 1981 to 1995, 86% were men and 14% were women. Among women, 69.7% were black and 29.1% were white. Among men, 48.4% were black and 50.9% were white. We compared these figures with 1995 Alabama population estimates of 26.2% black, 73.7% white, and < 1% another race. The rates for black women and white women increased 170-fold and 23-fold, respectively, from the 1981 to 1985 period to the 1991 to 1995 period. For the same periods, case rates for black men and white men increased more than 80-fold and 50-fold, respectively. Black women showed a rise per 100,000 population-from 0.3 (1981 to 1985) in both northern and southern Alabama to 37 in northern Alabama and 64 in southern Alabama (1991 to 1995).

CONCLUSIONS

Black women are at disproportionately high risk, particularly in the southern counties of Alabama. HIV is increasingly prevalent in rural and small town communities in Alabama and is more often transmitted heterosexually than it has been previously.

Initial experience with an absorbable laparoscopic ligation clip

BACKGROUND

Laparoscopic surgery requires secure and safe methods of ligation and haemostasis. This study evaluated the efficacy of an absorbable ligation clip with a novel compression closure mechanism.

METHODS

A new compression-closure absorbable clip was compared with currently available absorbable and non-absorbable clips used in a variety of laparoscopic procedures in 12 centres worldwide.

RESULTS

At follow-up to 3 months after the procedure, no complications specific to the use of the compression-closure clip were detected. Operator satisfaction with the clip was high, with criticism directed at its relatively large size.

CONCLUSION

This new clip is as safe and effective as presently available metal and absorbable clips in providing haemostasis and securing tubular structures.

Cloning and expression of two human lysophosphatidic acid acyltransferase cDNAs that enhance cytokine-induced signaling responses in cells

Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are two phospholipids involved in signal transduction and in lipid biosynthesis in cells. LPA acyltransferase (LPAAT), also known as 1-acyl sn-glycerol-3-phosphate acetyltransferase (EC 2.3.1.51), catalyzes the conversion of LPA to PA. In this study, we describe the isolation and characterization of two human cDNAs that encode proteins possessing LPAAT activities. These two proteins, designated here as LPAAT-alpha and LPAAT-beta, contain extensive sequence sequence similarities to microbial or plant LPAAT sequences. LPAAT-alpha mRNA was detected in all tissues with highest expression in skeletal muscle whereas LPAAT-beta was expressed predominantly in heart and liver tissues. Expression of these two cDNAs in an Escherichia coli strain with a mutated LPAAT gene (plsC) complements its growth defect and shifts the equilibrium of cellular lipid content from LPA to PA and other lipids. Overexpression of these two cDNAs in mammalian cells leads to increased LPAAT activity in cell-free extracts using an in vitro assay that measures the conversion of fluorescently labeled LPA to PA. This increase in LPAAT activity correlates with enhancement of transcription and synthesis of tumor necrosis factor-alpha and interleukin-6 from cells upon stimulation with interleukin-1beta, suggesting LPAAT overexpression may amplify cellular signaling responses from cytokines.

Pancreaticoduodenectomy for pancreatic adenocarcinoma: postoperative adjuvant chemoradiation improves survival. A prospective, single-institution experience

OBJECTIVE

This study was designed to evaluate prospectively survival after pancreaticoduodenectomy for pancreatic adenocarcinoma, comparing two different postoperative adjuvant chemoradiation protocol to those of no adjuvant therapy.

SUMMARY BACKGROUND DATA

Based on limited data from the Gastrointestinal Tumor Study Group, adjuvant chemoradiation therapy has been recommended after pancreaticoduodenectomy for adenocarcinoma of the head, neck, or uncinate process of the pancrease. However, many patients continue to receive no such therapy.

METHODS

From October 1991 through September 1995, all patients with resected, pathologically confirmed adenocarcinoma of the head, neck, or uncinate process of the pancreas were reviewed by a multidisciplinary group (surgery, radiation oncology, medical oncology, and pathology) and were offered three options for postoperative treatment after pancreaticoduodenectomy: 1) standard therapy: external beam radiation therapy to the pancreatic bed (4000-4500 cGy) given with two 3-day fluorouracil (5-FU) courses and followed by weekly bolus 5-FU (500 mg/m2 per day) for 4 months; 2) intensive therapy: external beam radiation therapy to the pancreatic bed (5040-5760 cGy) with prophylactic hepatic irradiation (2340-2700 cGy) given with and followed by infusional 5-FU (200 mg/m2 per day) plus leucovorin (5 mg/m2 per day) for 5 of 7 days for 4 months; or 3) no therapy: no postoperative radiation therapy or chemotherapy.

RESULTS

Pancreaticoduodenectomy was performed in 174 patients, with 1 in-hospital death (0.6%). Ninety-nine patients elected standard therapy, 21 elected intensive therapy, and 53 patients declined therapy. The three groups were comparable with respect to race, gender, intraoperative blood loss, tumor differentiation, lymph node status, tumor diameter, and resection margin status. Univariate analyses indicated that tumor diameter < 3 cm, intraoperative blood loss < 700 mL, absence of intraoperative blood transfusions, and use of adjuvant chemoradiation therapy were associated with significantly longer survival (p < 0.05). By Cox proportional hazards survival analysis, the most powerful predictors of outcome were tumor diameter, intraoperative blood loss, status of resection margins, and use of postoperative adjuvant therapy. The use of postoperative adjuvant chemoradiation therapy was a predictor of improved survival (median survival, 19.5 months compared to 13.5 months without therapy; p = 0.003). The intensive therapy group had no survival advantage when compared to that of the standard therapy group (median survival, 17.5 months vs. 21 months, p = not significant).

CONCLUSIONS

Adjuvant chemoradiation therapy significantly improves survival after pancreaticoduodenectomy for adenocarcinoma of the head, neck, or uncinate process of the pancreas. Based on these survival data, standard adjuvant chemoradiation therapy appears to be indicated for patients treated by pancreaticoduodenectomy for adenocarcinoma of the head, neck, or uncinate process of the pancreas. Intensive therapy conferred no survival advantage over standard therapy in this analysis.

Major bile duct injuries during laparoscopic cholecystectomy. Follow-up after combined surgical and radiologic management

OBJECTIVE

The authors provide the results of follow-up evaluation after combined surgical and radiologic management of 89 patients with major bile duct injuries during laparoscopic cholecystectomy.

SUMMARY BACKGROUND DATA

The incidence and mechanism of injury of major bile duct injuries during laparoscopic cholecystectomy has been clearly defined. Furthermore, a number of series have described the management of these injuries by surgical, endoscopic, and radiologic techniques with excellent short-term results. Long-term follow-up data, however, are lacking in the management of these injuries.

METHODS

Data were collected prospectively on 89 patients treated at a single institution with major bile duct injuries after laparoscopic cholecystectomy managed between July 1, 1990, and July 1, 1996. Patients referred with injuries underwent early percutaneous transhepatic cholangiography and biliary drainage. Based on the cholangiographic appearance and clinical situation, patients were managed by either percutaneous balloon dilatation or surgical reconstruction with a Roux-en-Y hepaticojejunostomy with transanastomotic stenting. Follow-up was obtained by personal interview during October 1996.

RESULTS

Two patients died without an attempt at definitive therapy. Both deaths were caused by sepsis and multisystem organ failure present at the time of transfer to the authors' institution. The remaining 87 patients were managed initially by either balloon dilatation (N = 28) or surgical reconstruction (N = 59). Ten patients have not completed treatment and still have biliary stents in place. Evaluation of 25 patients completing treatment after balloon dilatation (mean follow-up, 27.8 months) showed a success rate of 64%. Evaluation of 52 patients completing treatment after surgical reconstruction (mean follow-up, 33.4 months) showed a success rate of 92%. All failures were managed successfully by either surgical reconstruction or balloon dilatation.

CONCLUSIONS

Major bile duct injuries can be managed successfully by combined surgical and radiologic techniques. This series provides, for the first time, significant follow-up on a large number of patients with overall success rates of 64% after balloon dilatation and 92% after surgical reconstruction. The combination of surgery and balloon dilatation resulted in a successful outcome in 100% of patients treated.

TeleInViVo: a collaborative volume visualization application

Converging technologies in the areas of networks, volume visualization algorithms, and computer performance have made possible the development of a new tool for collaboration, which extends the reach of health professionals, and other consumers of volumetric data around the world. TeleInViVo(tm) is a three-dimensional (3D) collaborative volume visualization tool for medical applications. It extends the capabilities of InViVo(tm), a fast volume visualization tool developed at the Fraunhofer IGD, Darmstadt, Germany [1-3], with efficient and intuitive network collaboration features for remote consultation and new modes of interaction. The software runs on both UNIX and Windows NT platforms. TeleInViVo provides a high degree of interactivity for the medical professional when interacting with the patient data, facilitates explanation and communication between field personnel and medical experts located far from the field, and permits viewing of the data in a multitude of ways designed to support rapid and accurate diagnosis. Current efforts involve architectural enhancements to support multiuser, distributed telemedical scenarios. The application includes the following features: Volume and subvolume data transmission at user specified resolution, Synchronization cues, Integration of Immersion Probe(tm), a 6 degree-of-freedom input device, for ergonomic 3D data exploration, Tools for measuring distances, Tools for planning instrument path, Arbitrary cutting planes in real time, Interactive segmentation tools, Virtual video recorder and playback (cine loops), 3D stereo mode. TeleInViVo is an essential part of the MUSTPAC-1 portable 3D ultrasound system developed by Battelle Pacific Northwest Labs, Richland, WA.

Cholangiocarcinoma. A spectrum of intrahepatic, perihilar, and distal tumors

OBJECTIVE

The objective of this article is to introduce a simple method for classifying cholangiocarcinomas and to apply this system to analyze a large number of patients from a single institution.

SUMMARY BACKGROUND DATA

For the past 2 decades, most western reports on cholangiocarcinoma have separated intrahepatic from extrahepatic tumors and have subclassified this latter group into proximal, middle, and distal subgroups. However, "middle" lesions are uncommon and are managed most often either with hilar resection or with pancreatoduodenectomy. The spectrum of cholangiocarcinoma, therefore, is best classified into three broad groups: 1) intrahepatic, 2) perihilar, and 3) distal tumors. These categories correlate with anatomic distribution and imply preferred treatment.

METHODS

The records of all patients with histologically confirmed cholangiocarcinoma who underwent surgical exploration at The Johns Hopkins Hospital over a 23-year period were reviewed.

RESULTS

Of 294 patients with cholangiocarcinoma, 18 (6%) had intrahepatic, 196 (67%) had perihilar, and 80 (27%) had distal tumors. Age, gender, race, and associated diseases were similar among the three groups. Patients with intrahepatic tumors, by definition, were less likely (p < 0.01) to be jaundiced and more likely (p < 0.05) to present with abdominal pain. The resectability rate increased with a more distal location (50% vs. 56% vs. 91%), and resection improved survival at each site. Five-year survival rates for resected intrahepatic, perihilar, and distal tumors were 44%, 11%, and 28%, and median survival rates were 26, 19, and 22 months, respectively. Postoperative radiation therapy did not improve survival. In a multivariate analysis resection (p < 0.001. hazard ratio 2.80), negative microscopic margins (p < 0.01, hazard ratio 1.79), preoperative serum albumin (p < 0.04, hazard ratio 0.82), and postoperative sepsis (p < 0.001, hard ratio 0.27) were the best predictors of outcome.

CONCLUSIONS

Cholangiocarcinoma is best classified into three broad categories. Resection remains the primary treatment, whereas postoperative adjuvant radiation has no influence on survival. Therefore, new agents or strategies to deliver adjuvant therapy are needed to improve survival.

Elements of the employee selection process: interviewing operating room staff

Selecting the right staff for employment in an operating room (OR) is critical to the success of any OR manager. Legal considerations limit the ability to gather certain information. However, by applying the correct skills and techniques, the manager can develop an information base that will lead to better decisions when selecting employees who can contribute to an efficiently run department.

Biliary carcinoembryonic antigen levels are a marker for cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma develops in 5% to 15% of patients with choledochal cysts, sclerosing cholangitis, and intrahepatic stones. The detection of cholangiocarcinoma in patients with premalignant biliary conditions has been difficult. Serum levels of carcinoembryonic antigen (CEA) have been neither sensitive nor specific for the diagnosis of cholangiocarcinoma. However, CEA has been shown to be present in cholangiocarcinomas by immunohistochemical staining. Therefore, we measured the level of CEA excreted in bile in patients with benign strictures, premalignant biliary diseases, and cholangiocarcinoma.

PATIENTS AND METHODS

Bile was obtained from transhepatic stents in patients with benign biliary strictures (34), choledochal cysts (5), primary sclerosing cholangitis (6), intrahepatic cholelithiasis (5), and perihilar cholangiocarcinoma (25). Samples were analyzed for CEA using a solid phase, two-site immunoenzymetric assay.

RESULTS

Biliary CEA levels were significantly elevated (P < 0.01) in patients with cholangiocarcinoma (50.2 +/- 5.8 ng/mL) and intrahepatic cholelithiasis (57.4 +/- 10.4 ng/mL) compared with patients with benign strictures (10.1 +/- 3.9 ng/mL). Patients with sclerosing cholangitis (21.6 +/- 3.9 ng/mL) and choledochal cysts (20.0 +/- 16.5 ng/mL) had intermediate levels. In 5 patients undergoing resection of perihilar cholangiocarcinomas, the mean biliary CEA level decreased from a preoperative level of 46.8 +/- 6.7 ng/mL to a postoperative level of 11.3 +/- 5.6 ng/mL (P < 0.02). In 4 patients with progression of cholangiocarcinoma, biliary CEA increased from a mean of 53.3 +/- 6.9 ng/mL to 98.3 +/- 12.2 ng/mL (P < 0.02) over a mean interval of 9.5 months.

CONCLUSIONS

Increased levels of CEA can be detected in the bile of patients with chlolangiocarcinoma. Monitoring these levels may have a role in the management of cholangiocarcinoma as well as premalignant biliary conditions such as choledochal cysts and sclerosing cholangitis.

Confirmation of Borrelia burgdorferi spirochetes by polymerase chain reaction in placentas of women with reactive serology for Lyme antibodies

The purpose of our study was to determine whether Borrelia burgdorferi spirochetes were present in placentas of asymptomatic women with reactive Lyme serology using a silver stain, and to confirm the identity of the spirochetes by polymerase chain reaction (PCR). Sixty placentas of asymptomatic women with ELISA-positive or-equivocal serology for Lyme antibodies during pregnancy were examined for spirochetes using a silver stain. The results of the ELISA serology were confirmed by Western blot analysis. PCR amplification for B. burgdorferi was performed on placentas identified to have spirochetes and on a group of placentas negative for spirochetes. Spirochetes were identified by silver staining in 3 (5%) of the 60 placentas. PCR confirmed B. burgdorferi nucleotide sequences in 2 of the placentas. The 5 women had equivocal Lyme ELISA and negative syphilis serology. The results of the Western blot analysis were negative in 2 cases and indeterminate in 1 case. Six controls were negative for spirochetes by silver staining and PCR. A normal perinatal outcome was observed in all cases. Spirochetes identified in placental tissue of pregnancies with reactive Lyme serology were confirmed by PCR to be B. burgdorferi. There was no relationship between the presence of placental spirochetes and the results of Lyme serology or the pregnancy outcome.