Surveillance imaging in children with medulloblastoma (posterior fossa PNET)

BACKGROUND

The use of surveillance imaging in children with medulloblastoma has been criticised. The aim of this study was to determine what proportion of relapses are detected by surveillance and whether these are found at a relatively favourable stage.

METHODS

This study was a retrospective review of the medical charts and imaging studies of 89 patients treated at a single children's cancer centre. Relapse was defined as evidence of an increase in volume of residual tumour of greater than 25% or the presence of metastases, or new onset of positive CSF cytology. Relapse was termed symptomatic if it was diagnosed by tests performed because of new symptoms that occurred in the interval between surveillance examinations. Asymptomatic relapse was diagnosed solely on the basis of surveillance imaging. Survival time to relapse was calculated from the date of the first surgical procedure.

RESULTS

Surveillance imaging detected 17 (71%) of the 24 relapses that occurred later than 6 months after diagnosis. All seven patients who presented with symptoms between scans have died, with a median survival from relapse of 5 months. Median survival from relapse in the patients detected by surveillance was 44 months, and four remain alive at 44-75 months. The patients detected by surveillance tended to have less advanced disease, which was more amenable to salvage therapy.

CONCLUSION

This type of study cannot prove that surveillance imaging improves survival in children with medulloblastoma because of the effects of lead time and length biases. Despite this, surveillance does appear to be effective in detecting potentially curable medulloblastoma relapses and should be offered to all patients.

Comparison of classic and molecular approaches for the identification of untypeable enteroviruses

Members of the family Picornaviridae are the most common viruses infecting humans, and species in several genera also infect a wide variety of other mammals. Picornaviruses have traditionally been classified by antigenic type, based on a serum neutralization assay. However, this method is time-consuming and labor-intensive, is sensitive to virus aggregation and antigenic variation, and requires a large number of antisera to identify all serotypes, even when antiserum pools are used. We developed generic reverse transcription (RT)-PCR primers that will amplify all human enterovirus serotypes, as well as many rhinoviruses and other picornaviruses, and used RT-PCR amplification of the VP1 gene and amplicon sequencing to identify enteroviruses that were refractory to typing by neutralization with pooled antisera. Enterovirus serotypes determined by sequencing were confirmed by neutralization with monospecific antisera. Of 55 isolates tested, 49 were of known enterovirus serotypes, two were rhinoviruses, and four were clearly picornaviruses but did not match any known picornavirus sequence. All four untyped picornaviruses were closely related to one another in sequence, suggesting that they are of the same serotype. RT-PCR, coupled with amplicon sequencing, is a simple and rapid method for the typing and classification of picornaviruses and may lead to the identification of many new picornavirus serotypes.

Disease progression, adherence, and response to protease inhibitor therapy for HIV infection in an Urban Veterans Affairs Medical Center

Indinavir therapy has demonstrated promise in the treatment of HIV-1 infection in clinical trials; however, its efficacy in a U.S. Veterans Affairs Medical Center, where access to therapy is generally unimpeded, is unknown. A review of the Miami cohort was conducted for the year beginning May 1996 to evaluate response to indinavir plus two nucleoside analogues. Of 483 HIV-1-positive patients (97% male; mean age, 46.7+/-9.7 years), 266 were offered indinavir based on their having CD4 counts <200 cells/microl or viral loads >10,000 copies/ml. Of these patients, 36% were adherent and experienced significant reductions in viral loads (-93,325+/-147,911 copies/ml) and elevations in CD4+ (111+/-103 cells/microl) and CD8+ (225+/-338 cells/microl) T cell counts. Adherent patients with baseline CD4 counts <100 cells/microl were 4.5 times more likely to have follow-up viral loads >10,000 copies/ml than those with CD4 >200 cells/microl. Adherent patients with CD4 counts <100 cells/microl did not show evidence of immune "exhaustion" because they were equal to those with CD4 counts >200 cells/microl in their capacity to replenish CD4 cells. Nonadherence to the regimen resulted in loss of therapeutic benefit and suggested that strategies to enhance adherence may become an essential component of treatment.

Molecular epidemiology and genetic diversity of echovirus type 30 (E30): genotypes correlate with temporal dynamics of E30 isolation

Echovirus type 30 (E30) (genus, Enterovirus; family, Picornaviridae) has caused large outbreaks of aseptic meningitis in many regions of the world in the last 40 years. U.S. enterovirus surveillance data for the period 1961 to 1998 indicated that the annual proportion of E30 isolations relative to total enterovirus isolations has fluctuated widely, from a low of 0% in 1966 to a high of 42% in 1998. Peaks of E30 isolations occurred in the years 1968 to 1969, 1981 to 1984, 1990 to 1993, and 1997 to 1998, coincident with large nationwide outbreaks of E30-associated aseptic meningitis. Analysis of the complete VP1 sequence (876 nucleotides) of 136 E30 strains isolated in geographically dispersed regions of the United States and nine other countries between 1956 and 1998 indicated that the currently circulating E30 strains are genetically distinct from those isolated 30 to 40 years ago. Phylogenetic reconstruction demonstrated the existence of at least four distinct genetic groups, three of which have not been isolated in North America since 1981. Two of the three groups disappeared during periods when E30 was isolated infrequently. All North American E30 strains isolated after 1988 were closely related to one another, and all post-1993 isolates were of the same lineage within this group. Surveillance data indicate that E30 causes large national outbreaks of 2- to 4-year durations, separated by periods of relative quiescence. Our results show that shifts in the overall genetic diversity of E30 and the predominant genetic type correlate temporally with the dynamics of E30 isolation. The sequence data also provide a basis for the application of molecular techniques for future epidemiologic investigations of E30 disease.

Parasite-specific antibody profile in human fascioliasis: application for immunodiagnosis of infection

The antibody isotype response to an adult Fasciola worm antigen preparation (FWAP) was examined in sera from 60 Egyptians with parasitologically confirmed fascioliasis by an ELISA. The FWAP-specific IgG1 and IgG4 antibodies were found in 97-100% of the patients. The ratio of the mean absorbance values between infected patients and healthy controls was 9.7 and 29.7 for IgG1 and IgG4 antibodies, respectively. The IgM, IgA, IgG2, and IgG3 antibodies were less dominant. In contrast to IgG1 antibodies, which were often detected in sera from patients infected with Schistosoma, Echinococcus granulosus, Ascaris lumbricoides, Ancylostoma duodenale, or Hymenolepis nana, FWAP-specific IgG4 antibodies were detected exclusively in the sera of patients with fascioliasis. The data thus support the conclusion that an IgG4/ELISA with crude FWAP as antigen may be used for sensitive and accurate immunodiagnosis of human fascioliasis.

Specific detection of echoviruses 22 and 23 in cell culture supernatants by RT-PCR

Reverse transcription-polymerase chain reaction (RT-PCR) methods are available for the rapid detection of enteroviruses in clinical specimens or virus isolates. Pan-enterovirus PCR primers, however, fail to amplify echovirus (E) type 22 or 23 because of their extreme sequence divergence from the other enteroviruses. We have developed an RT-PCR method to detect specifically E22 and E23 RNA directly in tissue culture supernatants without a viral RNA purification step. The E22/E23 primers successfully amplified 20 of 20 clinical isolates of E22 and 4 of 4 E23 isolates representing viruses isolated in 15 states over a 19-year period, as well as E22 and E23 prototype strains isolated in the 1950s. The primers did not amplify any of the other 64 enterovirus prototype strains.

Typing of human enteroviruses by partial sequencing of VP1

Human enteroviruses (family Picornaviridae) are the major cause of aseptic meningitis and also cause a wide range of other acute illnesses, including neonatal sepsis-like disease, acute flaccid paralysis, and acute hemorrhagic conjunctivitis. The neutralization assay is usually used for enterovirus typing, but it is labor-intensive and time-consuming and standardized antisera are in limited supply. We have developed a molecular typing system based on reverse transcription-PCR and nucleotide sequencing of the 3' half of the genomic region encoding VP1. The standard PCR primers amplify approximately 450 bp of VP1 for most known human enterovirus serotypes. The serotype of an "unknown" may be inferred by comparison of the partial VP1 sequence to those in a database containing VP1 sequences for the prototype strains of all 66 human enterovirus serotypes. Fifty-one clinical isolates of known serotypes from the years 1991 to 1998 were amplified and sequenced, and the antigenic and molecular typing results agreed for all isolates. With one exception, the nucleotide sequences of homologous strains were at least 75% identical to one another (>88% amino acid identity). Strains with homologous serotypes were easily discriminated from those with heterologous serotypes by using these criteria for identification. This method can greatly reduce the time required to type an enterovirus isolate and can be used to type isolates that are difficult or impossible to type with standard immunological reagents. The technique may also be useful for the rapid determination of whether viruses isolated during an outbreak are epidemiologically related.

Molecular evolution of the human enteroviruses: correlation of serotype with VP1 sequence and application to picornavirus classification

Sixty-six human enterovirus serotypes have been identified by serum neutralization, but the molecular determinants of the serotypes are unknown. Since the picornavirus VP1 protein contains a number of neutralization domains, we hypothesized that the VP1 sequence should correspond with neutralization (serotype) and, hence, with phylogenetic lineage. To test this hypothesis and to analyze the phylogenetic relationships among the human enteroviruses, we determined the complete VP1 sequences of the prototype strains of 47 human enterovirus serotypes and 10 antigenic variants. Our sequences, together with those available from GenBank, comprise a database of complete VP1 sequences for all 66 human enterovirus serotypes plus additional strains of seven serotypes. Phylogenetic trees constructed from complete VP1 sequences produced the same four major clusters as published trees based on partial VP2 sequences; in contrast to the VP2 trees, however, in the VP1 trees strains of the same serotype were always monophyletic. In pairwise comparisons of complete VP1 sequences, enteroviruses of the same serotype were clearly distinguished from those of heterologous serotypes, and the limits of intraserotypic divergence appeared to be about 25% nucleotide sequence difference or 12% amino acid sequence difference. Pairwise comparisons suggested that coxsackie A11 and A15 viruses should be classified as strains of the same serotype, as should coxsackie A13 and A18 viruses. Pairwise identity scores also distinguished between enteroviruses of different clusters and enteroviruses from picornaviruses of different genera. The data suggest that VP1 sequence comparisons may be valuable in enterovirus typing and in picornavirus taxonomy by assisting in the genus assignment of unclassified picornaviruses.

Molecular phylogeny of all human enterovirus serotypes based on comparison of sequences at the 5' end of the region encoding VP2

Sixty-six human enterovirus serotypes have been described using antibody neutralization, with antigenic variants defined within several serotypes. Despite the availability of sequence data for numerous enteroviruses, the molecular basis of serotype is unknown. Previous studies by others have identified four major phylogenetic groups within the human enteroviruses, but there has been no complete database of homologous sequences for all human enterovirus serotypes. We have determined the homologous partial VP2 sequences for the 12 prototype strains for which VP2 sequence was unavailable and for eight well-characterized antigenic variants. Phylogenetic analysis of all prototype strains produced four major groups, consistent with published enterovirus phylogenies. Many antigenic variants, however, failed to cluster with their respective prototype strains, suggesting that this portion of VP2 may be inappropriate for consistent molecular inference of serotype and for detailed study of enterovirus evolution.

Complete sequence of echovirus 23 and its relationship to echovirus 22 and other human enteroviruses

To define the relationship between echovirus 23 (E23) and other human enteroviruses, we have determined the complete nucleotide sequence of a strain of E23 isolated from a child with high fever in Connecticut in 1986 and compared the nucleotide and deduced amino acid sequences with those of other enteroviruses representing each of the major enterovirus phylogenetic groups, poliovirus type 1, coxsackievirus A16, coxsackievirus B3, echovirus 22 (E22), and enterovirus 70. The genome of E23 (strain CT86-6760) was 7352 nucleotides in length, exclusive of the poly(A) tail, and the genome organization was typical of the picornaviruses. The nucleotide sequence and deduced amino acid sequences were most related to those of E22, a virus with which E23 shares many biological properties, and was quite divergent from the sequences of other enteroviruses (< 20% average amino sequence identity). These data lend further support to the suggestion that E22 and E23 are distinct from members of the Enterovirus genus and that they should be reclassified in a separate genus within the Picornaviridae.

Identifying opportunities to improve the management of care: a population-based diagnostic methodology

The growth of managed care and specifically capitation will dramatically change the basis of competition for health care providers. In order for medical groups to succeed in this new environment they must be able to accept the accountability for both managing the care of populations and managing the delivery of individual encounters of care. Being held accountable for the management of populations will require at-risk medical groups to focus on developing three entirely new strategic capabilities: the assessment of health risk, the management of access, and the management of care. This article describes the analytic approach of Deloitte & Touche Consulting Group's population-based diagnostic methodology, which will enable an at-risk organization to identify opportunities for improving the management of care for specific populations and diseases. The hypotheses driving the need for these organizations to establish population-based care management capabilities stem from the plethora of empirical evidence indicating significant variation in costs, utilization, and outcomes in the practice of medicine. Applying a systematic, planned approach to caring for patients who have common, predictable health care needs will result in better outcomes and lower costs for all.

Comparison of a monoclonal antibody-based IgM capture ELISA with a neutralization assay for assessing response to trivalent oral poliovirus vaccine

Monoclone-based IgM capture ELISAs were developed for each of the three poliovirus serotypes and compared with a neutralization assay for detecting response to trivalent oral poliovirus vaccine among 224 infants. The IgM-based response rates were significantly higher than the neutralizing antibody-based rates: 95% versus 83% to poliovirus type 1, 99% versus 94% to poliovirus type 2, and 89% versus 59% to poliovirus type 3. IgM responses to the first vaccine dose were significantly associated between serotypes, suggesting that some of the discordance may reflect a heterotypic IgM response. When the response rates in 4 vaccine formulation groups were compared, group differences using the two assays were similar for poliovirus types 1 and 2 but not for type 3. Therefore, IgM results using these assays may not be adequate substitutes for neutralizing antibody results when determining vaccine response.

Immunological correlates of disease severity in pediatric slow progressors with human immunodeficiency virus type 1 infection

Pediatric slow progressors are a group of HIV-1-infected individuals who are homogeneous for route and length of infection and standard of care and are therefore amenable to cross-sectional population studies on the immunological correlates of disease progression. We report here that both clinical and immunological categorizations of pediatric slow progressors based on the 1994 CDC criteria for symptom and immunosupression severity levels yield similar immunological findings: declining proportions of CD4 T cells are associated with increasing proportions of CD8 and CD4-CD8- T cells and with declining IL-2, -5, and -10 production levels by peripheral blood cells in response to the T cell-dependent mitogen, phytohemagglutinin, but not to the T and B cell-dependent mitogen from pokeweed. The latter cross-sectional results point to potential prognostic and nosologic markers and therapeutic targets among HIV-infected pediatric slow progressors. Longitudinal studies will help to assess further the relevance of these findings.

A new method for the estimation of the components of energy expenditure in patients with major trauma

The management of critically ill patients would be better understood if the total energy expenditure (TEE) and its components are known. To quantify the different components of energy expenditure in patients with major trauma, we used a technique combining measurements of body composition and oxygen consumption. We determined changes in body weight, total body water, total body protein, total body potassium, total body fat, and bone mineral content every 5 days over a 10-day period in a group of nine multiply injured patients. Resting energy expenditure was measured by indirect calorimetry (REEm), and a predicted value was obtained from total body potassium (REEp). TEE was assessed by adding the total calorie intake to the changes in body energy stores, and the activity energy expenditure (AEE) was calculated by subtracting REEm from TEE. Mean daily values for REEm, REEp, TEE, and AEE were 2,236 +/- 140, 1,683 +/- 82, 3,029 +/- 276, and 793 +/- 213 kcal/day, respectively, over the 10-day study period. Although not statistically significant, the mean AEE was four times smaller for the first 5 days of study than for the second 5 days (298 +/- 400 vs. 1,254 +/- 588 kcal/day). The technique of combining indirect calorimetry and body composition measurements offers a new approach to evaluate energy expenditure and a new way to study metabolic disorders and therapeutic strategies in critically ill patients.

Comparison of the ileal and faecal digestibility of dietary amino acids in adult humans and evaluation of the pig as a model animal for digestion studies in man

The aim of the study was to determine if there is a difference between ileal and faecal assays for determining amino acid and N digestibilities in adult human subjects. Comparison of true ileal amino acid and N digestibilities was also made between adult human subjects and growing pigs to establish the usefulness of the pig as a model animal. Five subjects with established ileostomies and six subjects with intact large bowels consumed a constant diet consisting of meat, vegetables, fruit, bread and dairy products for 7 d with collection of ileostomy contents or faeces respectively over the last 4 d. The study was repeated using 25 kg body weight ileostomized and intact pigs. Apparent amino acid and N digestibility coefficients were determined. For human subjects the faecal digestibility values were significantly higher (P < 0.05) than the ileal values for Arg, Asp, Gly, Phe, Pro, Ser, Thr and Trp. The faecal digestibility of Met was significantly lower than the ileal value. Determination of DNA, diaminopimelic acid (DAPA) and the digestibilities of pectin, hemicellulose and cellulose in human subjects indicated that some microbial colonization had occurred at the terminal ileum after formation of an ileostomy; however, this was not as extensive as in the large intestine. True ileum amino acid and N digestibilities were calculated after correcting for the endogenous contribution of amino acids at the terminal ileum determined using a protein-free diet. There were no significant differences between adult human subjects and pigs for true ileal dietary amino acid digestibility except for Thr, Phe, Cys and Met. There were no significant differences between adult humans and pigs for the ileal digestibility of dry matter and the faecal digestibility of gross energy.

T-cell receptor expression in lymphoid neoplasms. A comparison of phenotypic expression and genotyping

T-cell receptor antibodies (TCR alpha beta and TCR gamma delta) were used for a flow cytometric study of 114 specimens of lymphoid neoplasms and normal controls in order to find out whether or not the expression of TCR proteins differs in between normal and neoplastic tissues. It was found that TCR alpha beta population was predominant in all categories except T gamma lymphoproliferative disorder (TGLD), T-cell lymphoblastic leukemia (T-ALL), and natural killer-like T-cell lymphoma (NKTL), in which three of 18, one of three, and two of two specimens, respectively, showed a predominant TCR gamma delta population. Natural killer cell lymphoma (NKL) showed essentially absence of either TCR alpha beta or TCR gamma delta protein. Therefore, TCR antibodies can be selectively used in cases of TGLD, T-ALL, and NKTL to substantiate their diagnoses. Furthermore, the absence of TCR protein is characteristic of NKL and helps to distinguish it from NKTL. Without the TCR antibodies, TCR gene analysis is sometimes needed to separate these two entities. When comparing with genotyping, 11 of 12 cases with TCR beta gene rearrangement and one of two cases with TCR alpha gene rearrangement expressed TCR alpha beta protein. One of four cases with TCR gamma gene rearrangement and both cases with TCR delta gene rearrangement expressed TCR gamma delta protein. Thus, TCR antibody phenotyping can reliably predict TCR genotypes under most circumstances.

Collaborative nurse management of multifactorial moist desquamation in a patient undergoing radiotherapy

Consultation and collaboration between health care professionals can facilitate and improve patient care. In this case, Radiation Oncology and ET nurses collaborated in the care of a patient undergoing radiotherapy for esophageal carcinoma and concomitant corticosteroid therapy for cicatricial pemphigoid. The patient had moist skin desquamation during radiotherapy and was successfully treated by moist wound healing techniques with a hydrogel (Vigilon, C.R. Bard, Inc., Murray Hill, N.J.). The clinical success of nursing collaboration in this case affected assessment and treatment of moist desquamation in the Radiation Oncology department at one institution.

Manometric characterization of rectal dysfunction following radical hysterectomy

Bladder dysfunction thought to be due to partial denervation has been described following radical hysterectomy. Some patients experience acute and chronic rectal dysfunction characterized by difficulty with defecation and loss of defecatory urge. To define this abnormality, anorectal pressure profiles were examined in 15 patients with Stage I carcinoma of the cervix before and after radical hysterectomy. Profiles were done using standard anorectal manometry with a water-infused system. In all patients preoperative manometric profiles were normal; postoperative studies were abnormal in all patients. Features seen include altered relaxation of the internal sphincter, increased distension needed to trigger relaxation, and decreased rectal sensation; external sphincters and resting internal sphincters were unchanged. Postoperatively, 12 patients reported problems with rectal function. A physiologic defect is definable in patients undergoing radical hysterectomy; this suggests disruption of the spinal reflex arcs controlling rectal emptying. These physiologic abnormalities correlate with the clinical symptomatology experienced by some patients. Continuing definition and evaluation of management options in this situation should be useful in developing effective therapy for rectal dysfunction following radical hysterectomy.

Dietary management of the patient with massive enterectomy

We present two cases who required massive enterectomy and who represent different points in the spectrum of this disease. We discuss their management from a nutritional stand-point and show details of energy uptake and expenditure for one of our patients. This describes our approach to this problem, and we hope it will be of use to others when dealing with patients following massive enterectomy.

Coronary flow reserve, esophageal motility, and chest pain in patients with angiographically normal coronary arteries

PURPOSE AND METHODS

To ascertain the relative prevalence of abnormalities of coronary flow reserve and esophageal function in patients with chest pain despite angiographically normal coronary arteries, 87 patients underwent invasive study of coronary flow reserve and, during the same week, esophageal testing.

RESULTS

Sixty-three of the 87 patients (72%) demonstrated abnormalities of coronary flow reserve, as evidenced by an increase in coronary resistance during the stress of rapid atrial pacing after administration of ergonovine 0.15 mg intravenously (1.33 +/- 0.36 mm Hg.minute/mL), compared with pacing at the same heart rate before ergonovine administration (1.10 +/- 0.33 mm Hg.minute/mL). This higher coronary vascular resistance occurred in the absence of significant epicardial coronary artery luminal narrowing. Fifty-seven of these 63 patients (90%) with a coronary vasoconstrictor response to ergonovine described their typical chest pain during pacing stress, compared with only six of 24 patients (25%) who demonstrated no coronary flow abnormality (p less than 0.001). After administration of dipyridamole 0.5 to 0.75 mg/kg intravenously to 65 patients, the 48 patients with ergonovine-induced vasoconstriction had a significantly higher minimum coronary resistance, compared with the 17 patients without a coronary vasoconstrictor response to ergonovine (0.65 +/- 0.21 versus 0.47 +/- 0.13 mm Hg.minute/mL, p less than 0.03). Twenty of 87 patients (23%) had abnormal esophageal motility [nutcracker esophagus (11), nonspecific motility disorder (seven), and diffuse esophageal spasm (two)], including 16 of the 63 patients (25%) with abnormal coronary flow reserve. Twenty-four (28%) patients experienced their typical chest pain during motility testing, but only five of these patients met criteria for abnormal esophageal motility. Nine of 75 patients tested (12%) had their typical chest pain during Bernstein testing, and 18 of 38 patients (47%) tested had their typical chest pain provoked by intraesophageal balloon distention.

CONCLUSIONS

Seventy-one of 87 patients (82%) with anginal-like chest pain and normal epicardial vessels in our series had a disorder of either coronary flow reserve, esophageal motility, and/or reproduction of typical chest pain during acid infusion. Of interest, chest pain was commonly encountered during cardiac and esophageal testing (85% of patients), regardless of the ability to demonstrate an abnormality of coronary flow reserve or abnormal esophageal function. This suggests that pain experienced by these patients may be a consequence of myocardial ischemia, esophageal dysfunction, abnormal visceral nociception, or a combination of any or all of these entities.

The Whitaker test: experimental analysis in a canine model of partial ureteric obstruction

The Whitaker test has been described as a means of reaching a diagnosis in equivocal upper urinary tract obstruction, but there has been conflicting evidence regarding the validity of this test. The present study assesses the reliability of the test in an experimental model which creates an accurate and predetermined degree of partial obstruction of the ureter. The Whitaker test was performed using the standard perfusion rate of 10 ml./min. in male adult dogs using a long-term indwelling renal intrapelvic cannula before and after application of ureteric obstruction, and after one month. Control animals underwent a sham procedure. Results of in vivo and in vitro perfusion studies were compared. Perfusion studies at multiple flow rates were also performed. The Whitaker test reliably detected the presence of ureteric obstruction and the degree of partial obstruction could be determined. Multiple flow rate studies did not significantly improve test results. Provoked pressures in the highest grade of obstruction were less than expected and this may be due to pyelovenous reflux.