MasterOnline Periodontology and Implant Therapy-revisited after seven years: A case study of the structures and outcomes in a blended learning CPD

INTRODUCTION

There is a great need for postgraduate training and continuing professional development (CPD), specifically in the field of periodontology. Despite the plenty of periodontal CPDs, there is a lack of information about the performance of CPDs in a blended learning setting. This study is a case study of the structures and outcomes in a blended learning CPD programme in periodontology, the MasterOnline Periodontology and Implant Therapy hosted by the University of Freiburg's Dental School.

MATERIAL AND METHODS

The structures of the blended learning CPD were analysed with the aims to (i) make explicit how various innovative educational methods and ICT tools can be successfully applied to a Web-supported postgraduate periodontology training programme, (ii) identify the programme's impact on learning transfer in students' dental practices and (iii) identify other outcomes, synergies and any changes required during the existence. Using qualitative interviewing, the various types of learning transfer and elements of the study programme that foster transfer could be exemplified.

RESULTS

A period of 7 years was analysed. In this duration, 50 students successfully graduated to a master of science. Qualitative interviews were performed with six students and four teachers affirming the learning transfer in a blended learning setting.

CONCLUSIONS

This case study shows that blended learning can be a successful approach for CPD in dentistry.

Silencing vimentin expression decreases pulmonary metastases in a pre-diabetic mouse model of mammary tumor progression

Increased breast cancer risk and mortality has been associated with obesity and Type 2 diabetes (T2D). Hyperinsulinemia, a key factor in obesity, pre-diabetes and T2D, has been associated with decreased breast cancer survival. In the current study, a mouse model of pre-diabetes (MKR mouse) was used to investigate the mechanisms through which endogenous hyperinsulinemia promotes mammary tumor metastases. The MKR mice developed larger primary tumors and greater number of pulmonary metastases compared to wild type (WT) mice after injection with c-Myc/Vegf overexpressing MVT-1 cells. Analysis of the primary tumors showed significant increase in Vimentin protein expression in the MKR mice compared to WT. We hypothesized that Vimentin was an important mediator in the effect of hyperinsulinemia on breast cancer metastasis. Lentiviral shRNA knockdown of Vimentin led to a significant decrease in invasion of the MVT-1 cells and abrogated the increase in cell invasion in response to insulin. In the pre-diabetic MKR mouse, Vimentin knockdown led to a decrease in pulmonary metastases. In vitro, we found that insulin increased pAKT, prevented Caspase 3 activation, and increased Vimentin. Inhibiting the PI3K/AKT pathway, using NVP-BKM120, increased active Caspase 3 and decreased Vimentin levels. This study is the first to show that Vimentin plays an important role in tumor metastasis in vivo in the setting of pre-diabetes and endogenous hyperinsulinemia. Vimentin targeting may be an important therapeutic strategy to reduce metastases in patients with obesity, pre-diabetes or T2D.

One Episode of Self-Resolving Plasmodium yoelii Infection Transiently Exacerbates Chronic Mycobacterium tuberculosis Infection

Malaria and tuberculosis (Tb) are two of the main causes of death from infectious diseases globally. The pathogenic agents, Plasmodium parasites and Mycobacterium tuberculosis, are co-endemic in many regions in the world, however, compared to other co-infections like HIV/Tb or helminth/Tb, malaria/Tb has been given less attention both in clinical and immunological studies. Due to the lack of sufficient human data, the impact of malaria on Tb and vice versa is difficult to estimate but co-infections are likely to occur very frequently. Due to its immunomodulatory properties malaria might be an underestimated risk factor for latent or active Tb patients particularly in high-endemic malaria settings were people experience reinfections very frequently. In the present study, we used the non-lethal strain of Plasmodium yoelii to investigate, how one episode of self-resolving malaria impact on a chronic M. tuberculosis infection. P. yoelii co-infection resulted in exacerbation of Tb disease as demonstrated by increased pathology and cellular infiltration of the lungs which coincided with elevated levels of pro- and anti-inflammatory mediators. T cell responses were not impaired in co-infected mice but enhanced and likely contributed to increased cytokine production. We found a slight but statistically significant increase in M. tuberculosis burden in co-infected animals and increased lung CFU was positively correlated with elevated levels of TNFα but not IL-10. Infection with P. yoelii induced the recruitment of a CD11c⁺ population into lungs and spleens of M. tuberculosis infected mice. CD11c⁺ cells isolated from P. yoelii infected spleens promoted survival and growth of M. tuberculosis in vitro. 170 days after P. yoelii infection changes in immunopathology and cellular immune responses were no longer apparent while M. tuberculosis numbers were still slightly higher in lungs, but not in spleens of co-infected mice. In conclusion, one episode of P. yoelii co-infection transiently exacerbated disease severity but had no long-term consequences on disease progression and survival of M. tuberculosis infected mice.

An experimental model to study tuberculosis-malaria coinfection upon natural transmission of Mycobacterium tuberculosis and Plasmodium berghei

Coinfections naturally occur due to the geographic overlap of distinct types of pathogenic organisms. Concurrent infections most likely modulate the respective immune response to each single pathogen and may thereby affect pathogenesis and disease outcome. Coinfected patients may also respond differentially to anti-infective interventions. Coinfection between tuberculosis as caused by mycobacteria and the malaria parasite Plasmodium, both of which are coendemic in many parts of sub-Saharan Africa, has not been studied in detail. In order to approach the challenging but scientifically and clinically highly relevant question how malaria-tuberculosis coinfection modulate host immunity and the course of each disease, we established an experimental mouse model that allows us to dissect the elicited immune responses to both pathogens in the coinfected host. Of note, in order to most precisely mimic naturally acquired human infections, we perform experimental infections of mice with both pathogens by their natural routes of infection, i.e. aerosol and mosquito bite, respectively.

[Implementing in-patient smoking cessation interventions. Basic characteristics of smoking patients in a lung health department]

BACKGROUND

Hospitals have a unique key role in promoting smoking cessation. However, cessation interventions are uncommon in clinical routine despite their proven effectiveness. For planning a tailored intervention for hospitalised patients we examined the characteristics of smokers in our department for lung diseases.

METHODS AND PATIENTS

From July to September 2009 we evaluated the smoking status of all admitted patients. The smoking status was validated by measuring the CO-Hb. Smokers admitted for the first time on one of our regular wards received a comprehensive questionnaire. Patients with a duration of stay of 2 days or less and patients with substantial cognitive or linguistic limitations were excluded. Clinical data was collected from the participating smokers.

RESULTS

25% of all admitted patients were smokers. The participation rate was almost 90% of the eligible smokers. Our questionnaire was very well accepted und provided multitude helpful information for a following cessation counselling. Up to 3 or 4 smokers per day should be anticipated for a cessation intervention at an 80-bed-hospital. At least one counselling contact could be enabled. Although 75% of participants had experienced at least one unsuccessful quit attempt, only a minority used any support or help for cessation so far.

CONCLUSIONS

Specific questionnaires to evaluate the smoking history of patients in hospitals are very suitable and facilitate a subsequent bedside-counseling. To come up with their key role in promoting smoking cessation more hospitals as yet should implement cessation interventions.

Randomized phase II trial of docetaxel, with or without doxercalciferol, in advanced, androgen-independent prostate cancer

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Background: Docetaxel is the standard of care for advanced androgen-independent prostate cancer (AIPC). Doxercalciferol, a vitamin D analog (1a-hydroxyvitamin D2), has single-agent activity in AIPC (Clin Cancer Res 9(11), 2003). Preclinical evidence supports combining vitamin D with chemotherapy to treat AIPC. Here we report results of a multi-institutional trial combining docetaxel and doxercalciferol. Methods: Patients with chemo-naive AIPC were randomized 1:1 to receive, on a four week cycle, docetaxel (35 mg/m2 IV; days 1, 8 and 15) with either doxercalciferol (10 mcg PO daily, days 1–28) or placebo in a double-blind fashion. The primary endpoint was to compare progression-free survival (PFS). Secondary endpoints were to assess overall survival (OS), objective response (RECIST), PSA response (consensus criteria), and toxicity. PFS and OS were analyzed on an intent-to-treat basis. Eligibility criteria included no prior cytotoxic therapy; radiographic evidence of metastasis; performance status ≤ 2 and no recent history of nephrolithiasis. Results: Seventy patients were randomized. Median follow-up time was 16.2 months (range, 0–40.5 months). Median PFS in the doxercalciferol arm was 14.9 months (95% CI: 8.7–16.6 months) versus 11.9 months (95% CI: 8.9–16.4 months) in the placebo arm (p=0.73). Median OS in the doxercalciferol arm was 18.1 months (95% CI: 14.9–26.2 months) and 17.9 months (95% CI: 12.1–24.6 months) in the placebo arm (p=0.63). Twenty-nine patients in the doxercalciferol arm and 33 in the placebo arm were evaluable for objective response. No complete responses were seen. Partial response rate was 14% (doxercalciferol) vs. 15% (placebo) (p=0.88). PSA response rate was 44% (95% CI: 29%-60%) in the doxercalciferol arm and 42% (95% CI: 27%-59%) in the placebo arm (p=0.87). Grade 3/4 toxicity rates were 38% in the doxercalciferol arm and 39% in the placebo arm (p=0.99). Conclusions: Despite encouraging data with other vitamin D analogs combined with docetaxel in AIPC, the addition of daily doxercalciferol to weekly docetaxel did not enhance median PFS, OS or tumor response. Toxicity was similar between treatment groups. Further evaluation of vitamin D analogs in combination with chemotherapy in AIPC remains of interest.

No significant financial relationships to disclose.

A feasibility study of VcR-CVAD with maintenance rituximab for untreated mantle cell lymphoma

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Introduction: Novel treatment strategies are needed for Mantle Cell Lymphoma (MCL). We have published the results of a study using a modified R-hyperCVAD induction followed by maintenance rituximab (Kahl et al, Ann Oncol 2006). This induction strategy yielded a complete response (CR) rate of 64%. Given the promising activity of bortezomib (VELCADER) in relapsed MCL, we hypothesized that the incorporation of VELCADE (Vc) into the induction regimen would improve the CR rate. Methods: Eligible patients have histologically confirmed MCL, PS 0–2, and adequate end organ function. VcR-CVAD regimen: Velcade 1.3 mg/m2 days 1 and 4, rituximab 375 mg/m2 IV day 1, cyclophosphamide 300 mg/m2 IV over 3 hrs q 12 hrs X 6 doses days 1–3, doxorubicin 50 mg/m2 CI over days 1–2, vincristine 2 mg IV day 3, dexamethasone 40 mg po days 1–4. The first 7 patients received a Vc dose of 1.5mg/m2 on days 1 and 4 but this was modified to 1.3 mg/m2 due to excessive peripheral neuropathy (PN). Cycles are repeated every 21 days for 6 cycles and all patients receive G-CSF cytokine support. Patients achieving at least a PR receive maintenance rituximab therapy. Results: Currently 15 patients are enrolled with 13 having completed the VcR-CVAD induction and two in active treatment. Patient characteristics: 11M, 4F, median age 64 (49–73), and 13/15 stage IV. Of the 13 assessable patients, one experienced PD during induction therapy and expired. The remaining 12 patients have all achieved a complete response (CR rate 92%) and are currently receiving maintenance rituximab. The major toxicities of this treatment regimen are painful PN and expected hematological toxicity. Five/seven patients at 1.5 mg/m2 and 3/6 patients at 1.3 mg/m2 experienced grade 3–4 PN. All PN eventually resolved to grade 1- 2 and resolved faster in the patients receiving 1.3 mg/m2. Conclusion: The VcR-CVAD induction has produced high overall and complete response rates (92%) in a very representative MCL patient population. A Vc dose of 1.3 mg/m2 is better tolerated than a dose of 1.5 mg/m2. However, PN remains an issue and the final cohort in this feasibility study will receive a vincristine dose of 1 mg. The encouraging response rates noted in this pilot study provide the basis for ECOG protocol 1405, which will test this regimen in a cooperative group setting.

No significant financial relationships to disclose.

Maintenance rituximab following induction chemoimmunotherapy may prolong progression-free survival in mantle cell lymphoma: a pilot study from the Wisconsin Oncology Network

BACKGROUND

There is no standard first line treatment for mantle cell lymphoma.

PATIENTS AND METHODS

This was a multicenter phase II pilot study of rituximab and modified hyper-fractionated cyclophosphamide, vincristine doxorubicin, dexamethasone (modified R-hyperCVAD) administered every 28 days for four to six cycles followed by rituximab maintenance therapy consisting of four weekly doses every 6 months for 2 years. Unlike traditional hyperCVAD regimens, no methotrexate or cytarabine was administered.

RESULTS

Of 22 patients, the overall response rate was 77% and the complete response rate was 64%. With a median follow-up time of 37 months in surviving patients, the median PFS was 37 months and the median OS was not reached. The achievement of a molecular remission did not correlate with improved outcome. The major toxicity was expected myelosuppression. Two patients died during induction treatment. There were no major adverse effects during maintenance therapy.

CONCLUSION

In a multicenter trial, modified R-hyperCVAD was tolerable and effective induction therapy for untreated MCL. Maintenance rituximab appeared to prolong PFS without increasing toxicity.

Piezosurgery—a new safe technique in cranial osteoplasty?

All surgical interventions on the neurocranium bear the risk of injury of the dura mater and development of a cerebrospinal fluid fistula. Therefore, despite careful preparation, damage to the dura mater cannot always be omitted. Especially after surgery and in patients with increased intracranial pressure (craniosynostoses) there is a high risk of perforating the dura. In this article a new surgical technique for osteotomy (Piezosurgery) that avoids perforation of the dura is presented. Ultrasonic microvibrations allow a selective cut of only mineralized structures without damage to the soft tissue. Even in case of accidental contact the dura remains undamaged. This advantage is also useful for bone splitting, to separate the tabula externa from the tabula interna in situ, without any risk of dura perforation even in case of the very thin bones in an infantile skull. The present work shows the applicability of piezoelectric surgery in high-risk patients after osteotomy, avoiding perforation of the dura mater.

The influence of His94 and Pro149 in modulating the activity of V. cholerae DsbA

DsbA is the primary catalyst of disulfide bond formation in the periplasm of gram-negative bacteria. Numerous theoretical and experimental studies have been undertaken to determine the molecular mechanisms by which DsbA acts as a potent oxidant, whereas the homologous cytoplasmic protein, thioredoxin, acts as a reductant. Many of these studies have focused on the nature of the two residues that lie between the active-site cysteines. Although these are clearly important, they are not solely responsible for the differences in activity between these thiol-disulfide oxidoreductases. Q97 in the helical domain of E. coli DsbA has been implicated in influencing the redox potential of E. coli DsbA. In V. cholerae DsbA, the analogous residue is H94. In this study, the effect of H94 on the oxidase activity of DsbA is examined, along with the role of the conserved cis-proline residue P149. The DsbA mutant H94L shows a nearly fourfold increase in activity over the wild-type enzyme. To our knowledge, this is the first time an increase in the normal activity of a thiol-disulfide oxidoreductase has been reported. Potential reasons for this increase in activity are discussed.

Inclusion of older women in randomized clinical trials: factors associated with taking study medication in the fracture intervention trial

OBJECTIVES

The purpose of this study is to describe the early study medication discontinuation (SMD) experience during the first year of follow-up in a randomized clinical trial in older women and to determine the associations between various baseline characteristics and risk of SMD. DESIGH, SETTING, AND PARTICIPANTS: The authors studied 6,459 postmenopausal women aged 55 to 80 from 11 clinical settings during their first year of participation in the Fracture Intervention Trial (FIT). This trial was designed to test the efficacy of alendronate (Fosamax) on fracture prevention among women with low bone mass.

RESULTS

Study medication discontinuation was greatest in the first month post-randomization (2.2%) and declined thereafter. Cumulative rates of study medication discontinuation were 4.8% (n = 311) at 3 months and 11.1% (n = 717) at 12 months. SMD was not associated with age, marital status, alcohol consumption, regular exercise, past estrogen replacement therapy use, bone mineral density, or personal or maternal fracture history. After adjusting for covariates and markers of comorbidity, the strongest predictor of SMD was fair-to-poor self-rated health (relative risk (RR) 2.10; 95% confidence interval (CI) 1.47, 2.99). Having four or more depressive symptoms was also a significant predictor and had a risk associated with SMD (RR vs none 1.34; 95% CI 1.05, 1.71) similar to that seen for individuals with good self-rated health (RR 1.49; 95% CI 1.16, 1.91).

CONCLUSIONS

Results from this cohort emphasize that clinical trials in older women with multiple concomitant conditions can achieve high levels of adherence. Thought should be given to measuring self-rated health and depressive symptoms before randomization to help identify individuals to be targeted for special assistance programs that focus on encouraging adherence.

A comparison of two controlled-release delivery systems for the delivery of amiloride to control angiogenesis

The diuretic amiloride has been reported to inhibit both Na+-H+ antiport and the urokinase-type plasminogen activator. As a consequence of these inhibitions, neovascularization may also be inhibited. We hypothesized that if amiloride could be effectively delivered in a site-specific manner, a system might be developed that could inhibit localized angiogenesis. In order to evaluate this possibility we conducted a study that compared two different controlled-release systems into which amiloride had been incorporated. The effectiveness of amiloride release from each delivery system was determined by quantitating angiogenic patterns in a chick chorioallantoic membrane (CAM) system using a fractal analysis software program. The two delivery systems compared were sucrose acetate isobutyrate (SAIB) and calcium alginate. Initial HPLC laboratory tests confirmed that amiloride could be released from both SAIB and calcium alginate in vitro in a sustained manner for 72 h. The CAM studies confirmed that neither SAIB nor calcium alginate alone promoted or inhibited angiogenesis when compared to nontreated controls. The release of amiloride from each delivery vehicle resulted in a significant (P < 0.05) inhibition of angiogenesis following both 24 and 48 h of release compared to controls. There was no difference in inhibition of angiogenesis, however, when comparing SAIB + amiloride treated CAMs with calcium alginate + amiloride treated CAMs. These data suggest that both SAIB and calcium alginate may be useful delivery vehicles for the localized application of amiloride to control angiogenesis. Such a system could potentially control tumor angiogenesis without systemic effects.

Mailing strategies and costs of recruiting heavy smokers in CARET, a large chemoprevention trial

Recruitment costs represent a major portion of the budget for large clinical trials during the initial years of the study. Further, the rate of recruitment affects allocation of resources in future years. To learn about the costs and yields of recruiting from different populations and under different mailing strategies, we monitored recruitment yields of eligible heavy smokers for the Carotene and Retinol Efficacy Trial (CARET) at the Portland Study Center. Yields from the mailings, measured by response rate, percent of potential participants randomized, and related costs per randomization varied both by mailing strategy and by population targeted. Yield and cost varied significantly across population sources. Less variation was observed among various mailing strategies. Tracking the recruitment process yield provided useful information that allowed us to adjust recruitment approaches and achieve our randomization goals quickly and economically.

Elongation factor Ts from Thermus thermophilus-- overproduction in Escherichia coli, quaternary structure and interaction with elongation factor Tu

The gene encoding the elongation factor Ts from Thermus thermophilus was sequenced, cloned and the protein overproduced in Escherichia coli. In comparison to the EF-Ts from E. coli with 282 amino acid residues, EF-Ts from T. thermophilus is considerably shorter, differing by 86 amino acids. EF-Ts from the thermophile is stable at high temperatures, which facilitates its separation from E. coli proteins. Purified T. thermophilus EF-Ts forms a homodimer with a disulfide bridge between the two cysteine residues at position 190. The modification of Cys19O by iodoacetamide affects neither the dimerization nor the ability of EF-Ts to facilitate the nucleotide exchange of elongation factor Tu. The disulfide bridge was detected only in purified EF-TS, but not in protein extracts immediately after cell disruption. The physiological role of this disulfide bridge remains, therefore, unclear. Besides the quaternary (EF-TU . EF-Ts)2 complex, a ternary EF-TU . EF-Ts2 complex was detected by gel permeation chromatography and polyacrylamide gel electrophoresis. Trypsin cleavage after Lys48 or modification of Cys78 yield inactive EF-Ts, that does not bind to EF-Tu but is still capable of forming homodimers.

Overexpression and purification of Thermus thermophilus elongation factors G, Tu, and Ts from Escherichia coli

The translation elongation factors G (EF-G), Tu (EF-Tu), and Ts (EF-Ts) from the extreme thermophilic bacterium Thermus thermophilus were overproduced in Escherichia coli. The fus gene coding for EF-G and the tufA gene coding for EF-Tu were expressed under the control of a tac promoter, whereas EF-Ts was overproduced with the T7 RNA polymerase system. A detailed description for the purification of the three elongation factors from E. coli is presented. EF-G and EF-Tu are isolated by Q-Sepharose FF chromatography, heat treatment at 65 or 60 degrees C, respectively, and Sephacryl S200 gel permeation chromatography. For the purification of EF-Ts, a heat denaturation step is followed by DEAE-cellulose chromatography and a cation exchange EMD-SO-3 650 column. The overproduced factors show the same properties as those purified from T. thermophilus. As the crystal structures of T. thermophilus EF-Tu and EF-G have been solved recently, many questions concerning the function of particular residues or domains arise, which may be best addressed by studying the in vitro behavior and structure of altered recombinant constructs. The methods presented here should facilitate such studies.

Autoimmune hemolysis following transfusion: a mimicking autoanti-D in a D- patient with alloanti-D

An 80-year-old group O, D- (rr) female with anti-C, -D, -E, and -Fya received four units of crossmatch-compatible red blood cells (RBCs). The direct antiglobulin test (DAT) was negative. Two weeks later, jaundice, dark urine, a 16% drop in hematocrit (Hct), a 20% reticulocyte count, and absent haptoglobin occurred. During the next month, her DAT was positive with anti-IgG and -C3d. Acid eluates, which repeatedly showed anti-D specificity, were nonreactive with enzyme-treated D- RBCs. Adsorption with D- RBCs reduced reactivity. An eluate from the adsorbing D- RBCs was nonreactive with D+ KBCs. These findings suggest an autoantibody mimicking alloanti-D. The patient was treated with prednisone and was transfused with group O, D- (rr), K-, Fy(a-) RBCs. Four months later, the Hct was stable. One year later, the DAT remained positive and the eluate demonstrated a panagglutinin.

Depletion of olfactory bulb norepinephrine by 6-OHDA disrupts chemical cue but not social recognition responses in male rats

In the present experiment, 6-OHDA was infused directly into the olfactory bulb (OB) to produce a localized neurotoxic lesion. Habituation/dishabituation behavioral tests were then conducted to measure recognition responses to chemical cues (urine as a stimulus) and to social stimuli (ovariectomized rat as a stimulus). Infusion of 6-OHDA resulted in a near complete depletion of OB-norepinephrine (NE), whereas it had little effect (15% reduction) on OB dopamine (DA) contents. Nor were any significant effects on hypothalamic, hippocampal, olfactory tubercle, and corpus striatal NE and DA contents observed. Behaviorally, dishabituation responses to chemical cues were greatly impaired, however, there was relatively little effect on social behavior dishabituation responses. These results demonstrate that 6-OHDA can be used to produce a near complete but localized depletion of OB-NE. This treatment impairs dishabituation responses to chemical cues but not social stimuli indicating that OB-NE appears necessary for processing of chemical cue, but not social memory recognition process.

Selection for active E. coli tRNA(Phe) variants from a randomized library using two proteins

In vitro selection was used to isolate active Escherichia coli tRNA(Phe) variants from randomized libraries. Functional tRNAs were first selected by multiple rounds of binding to Escherichia coli phenylalanyl-tRNA synthetase. These variants were then aminoacylated and selected for affinity to elongation factor-Tu. By randomizing potential recognition nucleotides, the importance of residues U20, G34, A35, A36 and U59, previously identified to be required for specific recognition by E. coli phenylalanyl-tRNA synthetase (FRS), was confirmed. However, the sequences of several active variants imply that the wild-type tertiary interactions G10-C25-U45 and A26-G44 are not required for recognition, as previously suggested. Selection of functional tRNAs from a second library randomized at positions normally involved in conserved tertiary interactions revealed new combinations of nucleotides at these positions, suggesting the presence of novel tertiary interactions. In both libraries, active sequences containing deletions were isolated. Taken together, it is clear that FRS is active with substrates having an unexpectedly broad sequence diversity. Finally, the potency of this method is illustrated by the identification of a second class of variants that was isolated by virtue of the presence of an impurity in the FRS preparation.

Nitrogen-dioxide-induced emphysema in rats. Lack of worsening by beta-aminopropionitrile treatment

We evaluated the effect of beta-aminopropionitrile (beta APN) on the nitrogen dioxide (NO2) animal model of emphysema. Rats maintained on a beta APN-supplemented or a regular diet were exposed to 30 ppm NO2 for intervals ranging from 1 to 8 wk. Emphysema development was assessed by histologic evaluation and by changes in lung volume and mean linear intercept values. Evidence of pathologic changes were also documented by clinical and radiographic findings of osteolathyrism. The induction of centriacinar emphysema was attributed specifically to NO2 exposure. Neither the severity of the emphysema nor the time course of its development was altered by the beta APN-supplemented diet. These findings are in marked contrast to those observed with the exogenous elastase model of the disease, and they suggest that elastin synthesis and repair may not modulate elastin destruction in the NO2 model of emphysema.

Neutrophil recruitment and degranulation during induction of emphysema in the rat by nitrogen dioxide

Rats exposed to 30 ppm NO2 continuously for 3 to 6 wk developed mild centriacinar air-space enlargement and mild interstitial fibrosis. The emphysematous changes did not become more severe after 6 wk with continued NO2 exposure for as long as 14 additional weeks. Elastase inhibitory capacity (EIC) and the total protein concentration increased acutely in lung lavage fluid, consistent with the histologic evidence of pulmonary edema, then subsided but remained above control levels for the entire exposure period. The ratio of EIC to total protein remained unchanged relative to that in control animals. Neutrophils accumulated in the lung and were recoverable by lavage with the same relative concentration profile as observed for total protein. The average elastase activity per neutrophil in cells recovered from the air space by lung lavage was 60% less than in cells recovered from peripheral blood. This was true for control or NO2-exposed rats. Thus, emphysematous changes in the NO2-exposed rat were accompanied by a marked neutrophil recruitment concomitant with an increased neutrophil elastase burden in the lung, which may have directly contributed to lesion development.

Accelerated destruction of radiolabeled red cells due to anti-Coltonb

A patient who developed anti-Cob in response to transfusion was studied. The antibody was a warm-reactive, high-titered, IgG alloantibody that did not fix complement, and reacted strongly in the antiglobulin phase. During a period of transfusion the patient developed a positive direct immunoglobulin test with anti-Cob recoverable in the eluate. Reactions were stronger with enzyme-treated red cells. Survival studies with 51Chromium-labeled red cells showed: 1) normal survival of Co(b-) red cells, and 2) accelerated destruction of Co(b+) red cells; initially, cells were destroyed with a one-half disappearance time of 4 days, but after about 4 days, the rate of destruction increased. This study, together with reported suspected transfusion reactions attributed to anti-Cob, suggest that anti-Cob should be considered a clinically significant antibody.

Transplantation of HLA-haploidentical T-cell-depleted marrow for leukemia: autologous marrow recovery with specific immune sensitization to donor antigens

Autologous marrow recovery without engraftment of donor marrow was observed after bone marrow transplantation (BMT) for two patients with acute lymphoblastic leukemia. Each had received marrow from a haploidentical mixed lymphocyte culture (MLC) reactive donor after pretransplant conditioning with total body irradiation and high-dose cyclophosphamide. To minimize graft-vs-host disease, the marrow was depleted of T cells in vitro by treatment with a monoclonal anti-T-cell antibody and complement. Two weeks after each transplant, reactive lymphocytes were noted transiently in the blood of each patient. Analysis of karyotype, HLA type, and in vitro MLC responsiveness proved the lymphocytes to be of host, not donor, origin. MLC studies showed rapid proliferative responses specifically to stimulating cells from the BMT donor, indicating in vivo sensitization to donor antigens. Return of hematopoietic function was markedly delayed, but it eventually normalized after several months, without evidence of chimerism. These studies confirm that some immune and hematopoietic stem cells of host origin survive the high-dose chemoradiotherapy used as transplant conditioning. Because these immune cells are specifically reactive to donor alloantigens, more potent suppression of host immunity may be needed to prevent nonengraftment of T-cell-depleted, HLA-mismatched bone marrow.

Suppressed expression of blood group B antigen and blood group galactosyltransferase in a preleukemic subject

The B antigen activity was severely diminished in a patient's RBCs at the preleukemic stage prior to chemo- or radiotherapy. The amount of H sites of the patient's RBC membranes was found to be comparable to that of O RBC membranes. The activity of alpha (1----2) fucosyltransferase (H enzyme) was not severely decreased in the patient's plasma and bone marrow. However, the activity of alpha (1----3) galactosyltransferase (B enzyme), which converts H substance to B substance, was drastically reduced in the patient's bone marrow. Thus, the diminished B antigen in the patient's RBCs was caused mainly by the blockage of conversion of the H substance to B substance. It is suggested that the viral oncogene linked to the ABO locus at q34 of chromosome No. 9 would occasionally suppress the expression of blood group A and B enzymes and A and B antigens.

Relapse of host leukemic lymphoblasts following engraftment by an HLA-mismatched marrow transplant: mechanisms of escape from the "graft versus leukemia" effect

Leukemic relapses and graft versus host disease (GvHD) remain major complications following allogeneic bone marrow transplantation for leukemia. We present clinical and laboratory details for an eight-year-old boy who received a T-cell-depleted HLA-mismatched marrow transplant as therapy for acute lymphoblastic leukemia (ALL) in second remission. Engraftment with donor marrow was prompt and without any acute GvHD. Nevertheless, the patient's original ALL recurred and proved fatal. The patient remained a chimera with persistent donor lymphocytes present at the time of posttransplant relapse and subsequent to treatment with unsuccessful reinduction chemotherapy. In vitro immune studies showed that these leukemic cells could be recognized and destroyed by the donor's lymphocytes. The relapse itself suggests, however, that the donor's lymphocytes did not effectively destroy the patient's histoincompatible ALL cells in vivo following establishment of the chimeric state. Potential mechanisms are presented to account for this presumed "escape" from the postulated "graft versus leukemia" effect.

Blood component transfusion in the intensive care nursery. Indications and special problems

Increasingly, transfusions of component blood products are used in the setting of the neonatal intensive care unit. There is a need to analyze the indications and potential complications of this therapy critically. We review here the problems primarily unique to the neonatal population and suggest an approach to the transfusion requirements of this group. Specifically, we discuss the rationale, indications and complications of red cell, granulocyte, and platelet transfusions in these patients. Discussion of exchange transfusion and the particular blood banking requirements of these patients will be reviewed in subsequent articles.

Enzymatic inactivation of residual gentamicin after membrane filtration

RESIDUAL GENTAMICIN ON A MILLIPORE MEMBRANE WAS INACTIVATED BY MODIFICATION WITH TWO DIFFERENT ENZYMES: gentamicin adenylyltransferase and 3-N-acetyltransferase. Both modifications allowed the growth of susceptible strains of Escherichia coli and Bacillus subtilis.