Selective loss of progenitor subsets following clinical CD34+ cell enrichment by magnetic field, magnetic beads or chromatography separation

In this preclinical evaluation we have compared the efficacy of three clinical CD34+enrichment procedures with respect to purity, yield and recovery, as well as risk of selective loss of CD34+ lineage-specific subsets. The three devices work by different principles and have several different manipulation steps: The magnetic field separator uses paramagnetic iron-dextran particles; the magnetic microbead selection is based on the advantage of a large surface area for immobilisation of the monoclonal antibody within a very small volume; the original immunoabsorption technique is based on the use of biotinylated antibody applied to a column of avidin-coated sephadex beads. The results of this evaluation gave a median purity 96% (88-98%), 86% (62-97%), and 49% (18-85%), and median yield of 65% (54-100%), 40% (21-74%), and 30% (8-55%), respectively. Subset analysis recognised a selective loss of CD34+/61+ after enrichment, most likely due to class I-II antibodies used for the enrichment step or, alternatively, nonspecific binding of megakaryocytic progenitors. Tumour cell spiking experiments on a clinical scale documented an expected 2-4 log reduction resulting in a number of potentially malignant cells in the CD34 enriched product. Our data support four major conclusions: First, that magnetic field separation is superior to magnetic beads and chromatography selection, mainly due to the risk of cell loss and insufficient recovery with the two latter methods. Second, that late differentiated progenitors with CD34 class III epitopes present are lost during the enrichment procedures. The third major conclusion is that chromatography selection results in a selective loss of CD34bright cells, which are most likely uncommitted early progenitors. This was an unexpected finding which may be a consequence of an imbalance between the strong forces between biotin-avidin and insufficient physical manipulation for CD34+ cell release. Finally, the data document that CD34 selection alone is an inappropriate way to eliminate tumour cells due to the uncontrolled variables and the inconsistent outcome. The only products which can be expected to be purged free of tumour cells are the ones with very minimal (<10-5) contamination in the starting products, ie products documented tumour free with the most sensitive techniques for quantitation. If this is not the case, the optimal purging strategy may be a two-step procedure including CD34 selection and subsequent depletion of the tumour cells in question.

Circulating clonal cells in multiple myeloma do not express CD34 mRNA, as measured by single-cell and real-time RT-PCR assays

The peripheral blood (PB) mononuclear cells in patients with multiple myeloma (MM) have been reported to include CD34-expressing cells that are clonally related to the myeloma cells. To determine whether there were elevated levels of CD34 mRNA or whether CD34+ cells in the PB include myeloma-related cells, we developed a quantitative real-time and a competitive CD34 RT-PCR assay working on single flow-sorted cells. Myeloma-specific cells were detected with allele-specific oligonucleotides (ASO) IgH PCR. PBSC products and mononuclear cell fractions in blood from normal donors, untreated and treated myeloma patients were analysed. When measured by flow cytometry, the numbers of CD34+/CD19+ cells were consistently < 0.1% of the mononuclear cells. In addition, no significant difference was found in the levels of CD34 mRNA between normal subjects and untreated MM patients (P = 0.935). In the treated group of MM patients the CD34 mRNA levels were significantly reduced (P = 0.052) because of the stem cell toxicity of melphalan. Further, no cells clonally related to the MM clone were found within the CD34 compartment, defined by a sort-gate that included all cells expressing CD34 mRNA, as no cells outside the used CD34 sort-gate had a detectable level of CD34 mRNA. We conclude that in myeloma patients, the myeloma clone is not found within the CD34 compartment.

Mechanical circulatory support as a bridge to cardiac transplantation: toward the 21st century

Mechanical circulatory support is used to sustain the lives of patients awaiting cardiac transplantation who would otherwise die before a donor organ became available. Currently available ventricular assist devices used for mechanical circulatory support, risk factors and complications associated with use of these devices, and selection of candidates for treatment with mechanical support as a bridge to cardiac transplantation are reviewed. The importance of early insertion of the devices before end-organ dysfunction occurs is examined.

Mechanical circulatory support as a bridge to cardiac transplantation: toward the 21st century

Mechanical circulatory support is used to sustain the lives of patients awaiting cardiac transplantation who would otherwise die before a donor organ became available. Currently available ventricular assist devices used for mechanical circulatory support, risk factors and complications associated with use of these devices, and selection of candidates for treatment with mechanical support as a bridge to cardiac transplantation are reviewed. The importance of early insertion of the devices before end-organ dysfunction occurs is examined.

Comparison of the IFAT and Iscom-ELISA response in bovine foetuses with Neospora caninum infection

The study was carried out to evaluate the efficacy of foetal serology in the diagnosis of Neospora-associated bovine abortions. Fluids from 14 foetuses of cows with confirmed neosporosis (Group A), seven foetuses with confirmed bovine viral diarrhoea virus (BVD infection) (Group B) and 11 aborted foetuses without demonstrable infection (Group C) were examined. The age of the foetuses ranged from 4.5 months to 9 months. Albumin concentration (measured by Rocket Immunoelectrophoresis) was not significantly different in Group A compared with that in both Groups B and C, while that in Group B was significantly lower than in Group C. Levels of total IgG ranged from 0.01 to 1.78 (mg IgG) ml(-1) measured by single radial immunodiffusion technique. A measurable level of total IgG was found in all foetuses from Groups A and B, with no significant difference between levels in the two groups. Only one foetus in Group C had a detectable level of IgG. All foetuses in Group A had a specific IgG response (titre> or = 20) against Neospora caninum using the IFAT, while no positive responses in IFAT were found in Groups B and C. Measurement of specific IgG1 and IgG2 by Iscom-ELISA showed one and three false-negative results, respectively, in Group A. The IgG1 and IgG2 response in Group A was correlated according to the Spearman test (r = 0.66). Increasing age of the foetuses correlated significantly with the foetal IgG concentration, the specific IgG and IgG1 + IgG2. On the basis of the results obtained, it was concluded that the IFAT with a cut-off titre of 1:20, was a specific method for diagnosis of neosporosis in foetuses older than 4.5 months. The Iscom-ELISA also showed promising results as a method for screening specific antibodies against N. caninum in foetal fluid.

Pathogenicity of selected Toxoplasma gondii isolates in young pigs

The pathogenicity in 7-week-old pigs to five different Toxoplasma gondii strains of various host species origin was compared after i.v. inoculation of 10(4) tachyzoites. Additionally, one group of pigs was inoculated i.v. with 10(6) tachyzoites of the reference strain, SSI 119. In response to the infection a significant effect of T. gondii tachyzoite inoculation dose as well as differences among strains could be observed in several parameters. The 10(6)-dose inoculated pigs showed variable degrees of clinical illness and recurrent episodes of fever 4-17 days p.i., while pigs of four of the 10(4) tachyzoite inoculated groups experienced a short-lived rise in body temperature from day 6-8 p.i. without any apparent illness or inappetence. Control pigs and pigs infected with the least pathogenic strain had normal body temperature throughout the experiment. In all inoculated pigs, T. gondii-specific IgM and IgG antibodies appeared from day 8-10 and 10-17 p.i., respectively. Serum levels of alkaline phosphatase and the acute phase protein haptoglobin were decreased or increased, respectively, in response to the infection. Differential leukocyte count on peripheral blood revealed a significant lymphocytopenia on day 6 p.i. equal to both CD4+ and CD8+ T-cells, but shifting towards a reduced ratio of CD4+/CD8+ T-cells from day 8-14 p.i. In the 10(6)-dose inoculated pigs a considerable increase in zymosan induced and spontaneous oxidative burst capacity of peripheral blood leukocytes was observed from 6 days p.i. compared with control pigs. Oxidative burst capacity was not examined for other pigs. In conclusion, several useful parameters to identify differences in T. gondii pathogenicity other than mortality were identified. Furthermore, even at low doses, significant differences between recently collected Danish T. gondii field isolates were demonstrated after i.v. inoculation in young pigs.

The role of parvovirus B19 infection in childhood acute lymphoblastic leukemia

The authors hypothesized that parvovirus B19 with its hematotropic effects has the potential to precipitate varying forms of cytopenia in patients prior to or at the diagnosis of acute lymphoblastic leukemia (ALL). Consequently, and in view of the increasing number of cases reported, this retrospective study evaluated, for the first time, the possible role of parvovirus B19 infection in pediatric patients suffering from ALL, by investigating the frequency and clinical relevance of this infection at the time of the malignant diagnosis or, when applicable, during a phase of pre-ALL. Furthermore, a review of reported parvovirus B19 infections in pediatric ALL patients is presented. The serum of 65 consecutive pediatric patients with a diagnosis of ALL was examined for possible parvovirus B19 infection employing the polymerase chain reaction and ELISA techniques. Specific IgG was demonstrated in 30% of the patients. One patient diagnosed with pre-ALL had evidence of parvovirus B19 DNA in the serum during pancytopenia 5 months prior to the onset of ALL. The results suggest that there is an insignificant chance of finding a parvovirus B19 infection in pediatric patients with ALL at the time of diagnosis. However, parvovirus B19 infection may infrequently serve as a prodrome to ALL.

Subsets of CD34+ hematopoietic progenitors and platelet recovery after high dose chemotherapy and peripheral blood stem cell transplantation

BACKGROUND AND OBJECTIVE

Randomized clinical trials have shown that peripheral blood stem cell transplantations (PBSCT) with appropriate doses of CD34+ cells are associated with rapid, complete and sustained recovery of marrow functions. Nevertheless, in a minority af patients delayed platelet recovery may occur and it remains to be established whether analysis of transplanted CD34+ cell subsets may demonstrate correlation with this phenomenon. We studied a series of 80 consecutive transplanted patients with the aim of evaluating the effect of CD34+ stem cell numbers and, in a subgroup of 32 patients, the effect of the lineage specific subset numbers on time to platelet engraftment (i.e. time to platelet counts higher than 20x10(9)/L for two consecutive days without the need for platelet transfusions).

DESIGN AND METHODS

Different clinical and paraclinical factors were examined in a multivariate analysis for effect on platelet engraftment in 80 patients.

RESULTS

The number of CD34+ cells/kg infused was the most important factor predicting the time to platelet engraftment. Patients receiving more than 10x10(6) CD34+ cells/kg had prompt platelet engraftment. The majority of the patients (78%) received fewer than 10x10(3) CD34+ cells/kg and 17/62 (27%) of these patients experienced delayed platelet engraftment. In 32 patients receiving fewer than 10x10(6) CD34+ cells/kg we focused on the content of different lineage specific CD34+ subsets in the PBSC products. The most significant correlation was recognized for CD34+/CD61+ megakaryocytic cell number and platelet engraftment. An inverse correlation between the CD34+/CD38Eth subset and platelet engraftment was found, indicating that a high number of CD34+/CD38Eth in the PBSC product might increase the risk for delayed engraftment. These results were further confirmed by the observation that patients who experienced platelet engraftment after day 20 had significantly more CD34+/CD38Eth cells/kg infused than patients with fast engraftment.

INTERPRETATION AND CONCLUSIONS

The number of total CD34+ cells/kg infused was the most important factor predicting time to platelet engraftment. CD34+ subset analysis in a subgroup of patients suggests that a high number of uncommitted progenitors may be associated with slower platelet recovery than transplantation with a higher fraction of more committed peripheral blood stem cells.

Comparison of subjective classification of stool consistency and stool water content

OBJECTIVE

The purpose of this study was to compare the stool consistency categorizations made by 39 adults with fecal incontinence and the percentage of water in their stools determined by lyophilization.

METHODS

Subjects collected all stools daily for 8 days during a baseline period and at the end of a fiber treatment period. Stool consistency was recorded as hard and formed, soft but formed, loose and unformed, or liquid. Aliquots of the stools were lyophilized to constant weight.

MAIN OUTCOME MEASURES

The main outcome measures were the percentage of stool water among stools in each consistency category and the correlation between subjects' stool consistency categorizations and the percentage of stool water.

RESULTS

The subjects were 8 men and 21 women, ranging in age from 30 to 89 years, who were participating in a study of the effectiveness of dietary fiber for treating fecal incontinence. A total of 1023 stool samples were analyzed. Significant differences in the mean percentage of water were found among the 4 stool consistency categories (hard and formed = 68% +/- 0.9%, soft but formed = 74% +/- 0.3%, loose and unformed = 80% +/- 0.4%, and liquid = 85% +/- 0.3%; P < .001). Ninety-six percent of the stools had a percentage of water within 2 SDs of the mean percentage of water of other stools in their consistency category.

CONCLUSION

This classification system of stool consistency is a valid and practical measure for clinical studies. It may be useful for clinicians and patients to evaluate outcomes of treatments directed at improving stool consistency.

Fas and Fas-ligand expression in seminomatous testes

Sixteen seminomas with surrounding tissue containing normal and precancerous (cis) seminiferous tubules were examined for the expression of Fas (CD95, APO-1) and Fas ligand (FasL) (CD95L). This was done by analyzing frozen specimens using immunohistochemistry with antibodies directed against Fas and FasL. The study showed that varying numbers (mean approx. 20%) of Fas-positive lymphocytes were present among tumor-infiltrating lymphocytes, but very few FasL-positive lymphocytes. Fas was not expressed by normal seminiferous tubules and only occasional Fas-positive epithelial cells were seen in cis tubules. FasL was expressed in 9 out of 10 cases in virtually all normal seminiferous tubules, mainly as a thin layer at the base of the seminiferous epithelium. In precancerous tubules, this layer was discontinuous and less pronounced. Rete testis expressed FasL in 2 out of 2 cases with rete present and Fas in 1 out of 1 case. Invasive tumor cells did not express Fas or FasL. The data are discussed in relation to immune reactions to seminomas and to the concept of the testis being an immunologically privileged area.

Intravenous magnesium reduces infarct size after ischemia/reperfusion injury combined with a thrombogenic lesion in the left anterior descending artery

Experimental studies have demonstrated that intravenous magnesium (Mg) can protect the ischemic myocardium and has an antithrombotic effect. In patients with myocardial infarction, the reperfusion injury is complicated by the presence of a thrombogenic area in the affected coronary artery that may cause repetitive thrombus formation and embolization. We investigated the effect of Mg on infarct size in a randomized study in pigs. Myocardial infarction was induced by a 50-minute mechanical occlusion of the left anterior descending artery combined with an arterial injury, which stimulated a dynamic thrombus formation with emboli shedding on reperfusion. Magnesium sulfate (6 mmol/20 min plus 3 mmol/h) or saline was started at 30 minutes after coronary occlusion. Real-time ventricular pressure-volume loops were generated from the left ventricle by using a microtip pressure manometer and a conductance catheter. Platelet accumulation in the myocardium was evaluated by using 111In-labeled platelets. After 4 hours of reperfusion, the infarct size/area at risk ratio in the placebo group was 46+/-0.06% (n=8) compared with 22+/-0.07% (n=6) in the Mg-treated animals (P=0. 03). Ejection fraction decreased significantly in the control group but not in the Mg-treated animals (P=0.03). Platelet accumulation in the myocardium did not change significantly between the Mg- and placebo-treated animals (placebo group, 191+/-19%; Mg group, 177+/-29%; NS). The present study demonstrates that intravenous Mg infusion is able to reduce infarct size by >50% and preserve the ejection fraction in this model where ischemia/reperfusion injury was evaluated in the presence of a thrombogenic area in the nutrient artery.

Neospora caninum infection and repeated abortions in humans

To determine whether Neospora caninum, a parasite known to cause repeated abortions and stillbirths in cattle, also causes repeated abortions in humans, we retrospectively examined serum samples of 76 women with a history of abortions for evidence of N. caninum infection. No antibodies to the parasite were detected by enzyme-linked immunosorbent assay, immunofluorescence assay, or Western blot.

Age and gender differences in value orientation among American adolescents

This study investigated the development of a caring value orientation in four age groups. The sample included 1,247 students in grades 6, 8, 10, and 12 who were asked to complete a questionnaire, containing 14 contrasting word pairs and phrases, designed to measure preference for more caring, personal values. Gender differences were found across age groups and geographic regions. These findings are discussed in terms of theories that hypothesize gender differences in worldview.

Knowledge of HIV-positivity had no impact on AIDS survival time among Danish AIDS patients 1980-95

OBJECTIVE

To examine the impact of the time period from first positive HIV test to AIDS diagnosis and other variables on survival after AIDS diagnosis.

MATERIALS AND METHODS

All adult AIDS patients diagnosed and reported to the national surveillance unit in Denmark in the period 1980 through June 1995.

RESULTS

A total of 1745 patients was diagnosed in the period, and for 1631 (93.5%) the date of first positive HIV test was known. The median interval between this test and AIDS diagnosis was 912 d. Overall, 473 patients (29.0%) were found to be HIV-positive close to the AIDS diagnosis (< or = 4 months). The time interval between first positive HIV test and AIDS diagnosis varied by transmission categories. Patients older than 40 y had a higher mortality than younger patients. Patients infected by blood products had the highest mortality. The survival time was shortest for patients presenting with HIV-wasting or HIV-encephalopathy or with > or = 1 AIDS-defining disease. The time interval between first positive HIV test and AIDS diagnosis had no impact on survival.

CONCLUSION

No association was found between survival time and the time interval between first positive HIV test and AIDS diagnosis. Older age and transmission by blood or blood products were associated with shorter survival from AIDS diagnosis.

Comparison of rhG--CSF primed bone marrow and blood stem cell autografts: an analysis of engraftment in malignant lymphomas and solid tumours

Many studies have documented faster engraftment after transplantation with peripheral blood stem cells (PBSC) compared to bone marrow (BM) stem cells. Most comparisons, however, have been between unprimed BM and primed PBSC. We have collected engraftment data on 39 patients from 4 Danish centres and compared G-CSF primed BM with G-CSF primed PBSC in malignant lymphoma and solid tumours. In the lymphoma group 6 BM transplants were compared with 8 PBSC transplants, whereas in the testicular cancer group 16 BM transplants were compared with 9 PBSC transplants. In the lymphoma group, the time to platelet engraftment (platelets >20x10(9)/l unsupported) was median 15 d in PBSC transplants and median 34 d in BM transplants (p=0.003). In the solid tumour patients the difference in time to platelet engraftment was 11 and 18 d in PBSC and BM transplants, respectively (p<0.0001). In an attempt to explain this difference we performed CD34+ subset analysis of BM and PBSC. This analysis revealed a higher content of lineage restricted cells (CD34+CD61+ and CD34+GlyA+) in PBSC compared to BM. In conclusion, G-CSF mobilized PBSC seems to result in faster engraftment than G-CSF primed BM, which could be explained by an increased number of lineage specific progenitors in PBSC compared to BM.

Impact of a decision tree on chronic wound care

OBJECTIVE

To examine the use of a decision tree and its impact on the accuracy of decision making for chronic wound care.

DESIGN

Descriptive comparative design; replication study.

SETTINGS AND SUBJECTS

Data were collected from 2 groups of home care nurses in large urban centers. One group was measured after initial contact with the decision tree, and the other group was measured 2 years after implementation of the decision tree.

INSTRUMENTS

The chronic wound management decision tree (CWMDT) designed by Knight was used, in combination with pictorial case studies developed by Willey and Swords.

METHODS

Edmonton Home Care Program nurses, having used a decision tree for 2 years, completed 3 pictorial case studies without the aid of a written copy of the CWMDT. Current accuracy of wound care staging and treatment was compared with the Melchior-MacDougall and Lander results. After this procedure, Calgary Health Services home care nurses completed 3 pictorial case studies to assess the accuracy of wound care staging and treatment between 2 groups: with the CWMDT and without the CWMDT. A questionnaire was completed on factors identified to influence decision making in wound care.

MAIN OUTCOME MEASURE

Accuracy and confidence of decision making in wound care staging and treatment.

RESULTS

Accuracy of decision making with use of the CWMDT improved over time, as did accuracy of decision making after initial contact with the decision tree. Age, experience in nursing and home care, number of in-services attended, and number of chronic wounds treated, were not found to correlate with accuracy of decision making.

CONCLUSION

A decision tree can assist with decision making by guiding the nurse through assessment and treatment options.

Monoclonal antibodies to Toxoplasma gondii strain 119 identify recently isolated Danish strains as one group

Four mAb raised against the Danish Toxoplasma gondii strain 119, were selected by screening hybridoma supernatants by indirect immunofluorescence against tachyzoites of the RH strain in order to obtain strain-restricted markers. Strain restriction extended beyond discrimination of the 119 and RH strains, as demonstrated on a further six T. gondii reference strains [BK and GT1 (group A), NTE and 561 (group B), and NED and C56 (group C)]. The bradyzoite-specific mAb, 4.3, reacted to the GT1, NTE and 561 strains, but not to the BK, NED or C56 strains. The tachyzoite-specific mAb, 4.25, reacted to all strains tested except the RH strain, while mAb 5.1 reacted to tachyzoites of strains NTE and 561, but not to those of the BK, GT1, NED or C56 strains. Monoclonal antibody 5.15 reacted with the same strain restriction as monoclonal antibody 5.1, but to bradyzoites as well as tachyzoites. A T. gondii strain collection representative for a small geographic area (Denmark) was established within a short time span from a variety of animal species. Using the mAb as typing reagents to this Danish strain collection, all 36 animal and two human strains were identified as having the same reaction pattern as strains 119, NTE and 561.

Changing i.v. administration sets: is 48 versus 24 hours safe for neutropenic patients with cancer?

PURPOSE/OBJECTIVES

To examine the effects of changing i.v. administration sets at 48 versus 24 hours on the incidence of infusion-related septicemia in neutropenic patients with cancer.

DESIGN

Prospective, randomized clinical trial with repeated measures.

SETTING

Large urban cancer center.

SAMPLE

50 adult inpatients with a primary diagnosis of hematologic malignancy, breast cancer, or testicular cancer or who were receiving a stem cell transplant.

METHOD

Subjects were assigned randomly to have their i.v. sets changed every 48 or 24 hours. Subjects continued in the study for a maximum of five measurements, until they were no longer neutropenic, or until transferred or discharged from the hospital.

MAIN RESEARCH VARIABLES

Rates of infusate colonization, microorganisms identified, incidence of infusion-related septicemia.

FINDINGS

Colonized infusate was detected in 18 (5%) of 413 i.v. sets; 9 (5%) of 177 sets were changed at 48 hours, and 9 (4%) of 236 sets were changed at 24 hours (p > 0.05). A trend toward increased colonization of i.v. sets used to administer parenteral nutrition (19%) and, to a lesser extent, electrolytes (9%) was identified in the 48-hour group. Coagulase-negative staphylococci were the most frequently isolated microorganisms in the i.v. infusate. Similar organisms were isolated from blood cultures and administration sets, however, no subject had identical organisms isolated from both i.v. infusate and blood cultures. No subject with colonized infusate developed infusion-related septicemia.

CONCLUSIONS

No difference existed in the incidence of colonization or infusion-related septicemia between subjects whose i.v. administration sets were changed at 48 versus 24 hours.

IMPLICATIONS FOR NURSING PRACTICE

Changing i.v. administration sets every 48 hours is recommended. Exceptions to this include i.v. administration sets used to administer blood products and total parenteral nutrition.

A study of virulence parameters for Toxoplasma gondii infections in mice

With the aim of establishing assessments of the virulence of Toxoplasma gondii isolates for mice, we investigated weight loss, serum levels of haptoglobin, and serum levels of tumor necrosis factor-alpha (TNF-alpha) as alternative parameters to mouse mortality. Groups of BALB/c mice were inoculated i.p. with increasing parasite doses (5 x 10(1), 10(4), and 10(6)) of isolate 119 and with a low dose (5 x 10(1)) of isolates GT1 and NED. The inoculation dose was inversely correlated with the interval to the onset of weight loss (starting at days 9, 7, and 5, respectively) and the onset of increase in serum haptoglobin (starting at about days 8, 6, and 4, respectively). The GT1 strain (inducing 100% mortality at day 9) also gave the fastest response in terms of weight loss (onset by day 8) and increase in serum haptoglobin (onset by day 6), which occurred 1-2 days before these parameters were affected in the other low-dose groups. The low-dose NED and 119 inoculations were distinguished by continued weight loss, which lasted until day 20 in the former group (max. average weight loss 2.9 g as compared with 0.4 g).

Experimental porcine neosporosis

Six gilts were inoculated intramuscularly with 2.5x10(6) tachyzoites of Neospora caninum on three different days of gestation to study the pathogenic effect of Neospora infection in pigs, including possible transplacental transmission. The gilts were euthanized 59, 30, and 9/10 days postinoculation (p.i.), corresponding to days 107, 102/106 and 110/111 of pregnancy. With the exception of one animal (euthanized day 9 p.i.) all gilts seroconverted as measured by the indirect, fluorescent antibody test (IFAT). Neosporosis with multifocal intralobular necrotizing hepatitis was seen in the two gilts inoculated 9/10 days before euthanasia. The uterus of one gilt inoculated 59 days before euthanasia revealed granulomatous and focal necrotizing endometritis with a corresponding multifocal necrosis of the trophoblasts of two fetuses. Transplacental neosporosis was indicated in the two fetuses by strongly elevated Neospora IFAT titres in pleural fluid and by the presence of multifocal necrotizing encephalitis and hepatitis together with non-suppurative myocarditis, pneumonitis, nephritis and hepatitis. Furthermore, N. caninum was re-isolated in cell culture from one of these fetuses. A third fetus from the same gilt revealed only disseminated, pinpoint necroses in the liver. Immunohistochemically, N. caninum tachyzoites were detected in association with histopathological changes in the liver and the endometrium of the gilts, and in the brain, liver, and allantochorion of the three fetuses.

Incontinence after lateral internal sphincterotomy: anatomic and functional evaluation

PURPOSE

This study was designed to evaluate the anatomic and functional consequences of lateral internal sphincterotomy in patients who developed anal incontinence and in matched controls.

METHODS

The study includes 13 patients with anal incontinence after lateral internal sphincterotomy and 13 controls who underwent the same operation and were continent and satisfied with the results of the procedure. Patients underwent clinical evaluation, anorectal manometry, pudendal nerve terminal motor latency testing, and endoanal ultrasonography.

RESULTS

Sphincterotomies were longer in incontinent patients (75 vs. 57 percent), but the resting pressure and length of the high-pressure zone were not different between groups. Surprisingly, maximum voluntary contraction was higher in incontinent patients than in continent controls (136 vs. 100 mmHg). Rectal sensation and pudendal nerve terminal motor latency were similar in both groups. The defect in the internal sphincter was wider in incontinent patients than in continent controls (17.3 vs. 14.4 mm), but these differences were not statistically significant. The thickness of the internal sphincter measured by endoanal ultrasound was identical in both groups, but the external sphincter was thinner in incontinent patients both at the site of the sphincterotomy (6.8 vs. 8.1 mm) and in the posterior midline (7.1 vs. 8.6 mm).

CONCLUSIONS

Anal incontinence after lateral internal sphincterotomy is directly related to the length of the sphincterotomy. Whether secondary to preoperative sphincter abnormality or the result of lateral internal sphincterotomy, the external sphincter is thinner in incontinent patients than in continent controls.

Evaluation of mobilized CD34+ cell counts to guide timing and yield of large-scale collection by leukapheresis

We have previously reported a more than 50% risk of insufficient harvests (< 2 x 10(6) CD34+ cells/kg) following a fixed timing of leukapheresis in an unselected patient population collected for autologous stem cell transplantation. The failures were easily identified as patients who had < 20,000/ml CD34+ blood cells at the time of harvest. Consequently, in an attempt to optimize the timing strategy, we decided to perform daily analysis of the blood levels and perform leukapheresis within 24 h after the blood cell count exceeded 20,000 CD34+/ml. The results of this prospective study showed (a) that leukapheresis collections that were initiated based on the CD34+ blood level resulted in a success rate of 85% following 1-3 day harvests, (b) that high-level mobilizers with > 80,000 CD34+ cells/ml can be harvested successfully by only one procedure, and (c) that low-level mobilizers with < 40,000 CD34+ cells/ml still have a high risk of inadequate harvests. In summary, the optimized timing strategy is effective, but there is still room for improvement. First, new potent priming procedures for low-level and bad mobilizers are required, and second, algorithms to reduce the leukapheresis volume and time for high-level mobilizers should be established.

Adaptational effects during human split-belt walking: influence of afferent input

The modification of the normal locomotor pattern of humans was investigated using a split-belt locomotion protocol (treadmill belt speeds of 4.5 km/h and 1.5 km/h for the right and left legs, respectively) and also by changing afferent input from the legs (30% reduction or increase in body weight by suspending subjects in a parachute harness or by wearing a lead-filled vest). After a control-speed training period (10 min) of symmetrical walking (3 km/h each leg) and a period (10 min) of split-belt walking, the adjustment back to the control speed resulted in a mean speed difference between the right leg and the left leg of 0.85 km/h. Adjustment of belt speed on either side was performed by the hands using a potentiometer. For comparison, also speed adjustment by the feet via feedback derived from changes in the treadmill drive current was studied. No significant difference was obtained when both modes of adjustment were compared. Body unloading or loading during the training period resulted in an improved adjustment of treadmill belt speed. This suggests that load receptor information plays a major role in the programming of a new walking pattern.