Deletion of the homeodomain gene Six3 from kisspeptin neurons causes subfertility in female mice

The homeodomain transcription factor SIX3 is a known regulator of eye, nose, and forebrain development, and has recently been implicated in female reproduction. Germline heterozygosity of SIX3 is sufficient to cause subfertility, but the cell populations that mediate this role are unknown. The neuropeptide kisspeptin is a critical component of the reproductive axis and plays roles in sexual maturation, ovulation, and the maintenance of gonadotropin secretion. We used Cre-Lox technology to remove Six3 specifically from kisspeptin neurons in mice to test the hypothesis that SIX3 in kisspeptin neurons is required for reproduction. We found that loss of Six3 in kisspeptin neurons causes subfertility and estrous cycle irregularities in females, but no effect in males. Overall, we find that SIX3 expression in kisspeptin neurons is an important contributor to female fertility.

Kiss1 is differentially regulated in male and female mice by the homeodomain transcription factor VAX1

Regulation of Kiss1 transcription is crucial to the development and function of the reproductive axis. The homeodomain transcription factor, ventral anterior homeobox 1 (VAX1), has been implicated as a potential regulator of Kiss1 transcription. However, it is unknown whether VAX1 directly mediates transcription within kisspeptin neurons or works indirectly by acting upstream of kisspeptin neuron populations. This study tested the hypothesis that VAX1 within kisspeptin neurons regulates Kiss1 gene expression. We found that VAX1 acts as a repressor of Kiss1 in vitro and within the male arcuate nucleus in vivo. In female mice, we found that the loss of VAX1 caused a reduction in Kiss1 expression and Kiss1-containing neurons in the anteroventral periventricular nucleus at the time of the preovulatory luteinizing hormone surge, but was compensated by an increase in Kiss1-cFos colocalization. Despite changes in Kiss1 transcription, gonadotropin levels were unaffected and there were no impairments to fertility.

Management of Outbreaks of Methicillin-ResistantStaphylococcus aureusInfection in the Neonatal Intensive Care Unit: A Consensus Statement

Objective.

In 2002, the Chicago Department of Public Health (CDPH; Chicago, Illinois) convened the Chicago-Area Neonatal MRSA Working Group (CANMWG) to discuss and compare approaches aimed at control of methicillin-resistantStaphylococcus aureus(MRSA) in neonatal intensive care units (NICUs). To better understand these issues on a regional level, the CDPH and the Evanston Department of Health and Human Services (EDHHS; Evanston, Illinois) began an investigation.

Design.

Survey to collect demographic, clinical, microbiologic, and epidemiologic data on individual cases and clusters of MRSA infection; an additional survey collected data on infection control practices.

Setting.

Level III NICUs at Chicago-area hospitals.

Participants.

Neonates and healthcare workers associated with the level III NICUs.

Methods.

From June 2001 through September 2002, the participating hospitals reported all clusters of MRSA infection in their respective level III NICUs to the CDPH and the EDHHS.

Results.

Thirteen clusters of MRSA infection were detected in level III NICUs, and 149 MRSA-positive infants were reported. Infection control surveys showed that hospitals took different approaches for controlling MRSA colonization and infection in NICUs.

Conclusion.

The CANMWG developed recommendations for the prevention and control of MRSA colonization and infection in the NICU and agreed that recommendations should expand to include future data generated by further studies. Continuing partnerships between hospital infection control personnel and public health professionals will be crucial in honing appropriate guidelines for effective approaches to the management and control of MRSA colonization and infection in NICUs.

Changing the culture of hand hygiene compliance using a bundle that includes a violation letter

Hand hygiene is the best method of preventing transmission of infections in health care, but compliance is usually suboptimal. In one hospital, compliance with hand hygiene was improved and sustained using a multifaceted bundle approach. A unique aspect of the bundle was the creation of a violation letter that was sent to and enforced by managers of noncompliant personnel. The letter appeared to be the major factor in raising the hand hygiene compliance rate from 34% to >90% in a 2-year period.

Elevated expression of VEGFR-2 and VEGFA in desmoplastic small round cell tumor (DSRCT) and activity of bevacizumab and irinotecan in a xenograft model of DSRCT

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Background: Desmoplastic small round cell tumor (DSRCT) is an aggressive tumor with poor response to multimodality therapies. Given the vascular nature of many DSRCT, we sought to determine if VEGF targeting could be effective in a preclinical model of DSRCT. Methods: RNA was extracted from frozen tumor samples (DSRCT, alveolar soft part sarcoma, alveolar rhabdomyosarcoma, synovial sarcoma, and Ewing sarcoma) and a human DSRCT cell line, JN-DSRCT. Microarray profiling utilized Affymetrix U133A/B or Affymetrix U133 Plus 2.0 chips. DSRCT xenografts were established by intramuscular injection of 20 million JN-DSRCT cells into the lower extremity of SCID/bg mice. A primary tumor developed within 8 - 12 weeks with concomitant development of abdominal metastases. Mice were treated during primary tumor growth with bevacizumab (5ug/kg IP weekly), irinotecan (2.5mg/kg IP ×10 days q3 weeks), or a combination of both. Results: Microarray data demonstrated an average of 4.5 times higher RNA expression of VEGFR-2 (KDR) in DSRCT tumor samples as compared to the other translocation-associated sarcomas (p = 3.6 E-12). VEGFR-2 was highly expressed in the JN-DSRCT line as compared to other sarcoma lines. VEGFA was also highly overexpressed in the DSRCT line and tumor samples when compared to the other translocation-associated sarcomas (2.5 times, p = 1.1E-10). Xenografts treated with bevacizumab had slowed growth over 100 days compared to control groups (volume of 0.52 mm3 vs 1.52, p = 0.002). Marked long term regressions were evident following treatment with the combination of irinotecan plus bevacizumab compared with irinotecan alone (0.12mm3 vs 0.44 at 100 days, p < 0.0001). Conclusions: VEGFR-2 and VEGFA are overexpressed in DSRCT. DSRCT xenografts were highly responsive to bevacizumab or bevacizumab plus irinotecan. Taken together, the expression data and the sustained response of DSRCT xenografts to bevacizumab suggest that VEGF-dependent angiogenesis is important for DSRCT tumor biology and represents an attractive target for therapy. These studies suggest that irinotecan and bevacizumab should be considered for inclusion in clinical trials for the treatment of DSRCT.

No significant financial relationships to disclose.

Long-Term Effect of Xylitol Gum Use on Mutans Streptococci in Adults

Many studies have shown the effects of chewing xylitol gum on mutans streptococci (MS) over short- and long-term periods in children; however, few studies have addressed long-term periods in adults. The objective of this investigation was to examine for 6 months the effects of chewing xylitol gum on MS in saliva and plaque in 127 adults (mean age 28.0 years). The participants were assigned to three groups according to gum type, in part taking preference for flavor into account and in part at random: xylitol (XYL), maltitol (MAL) and control (CR); 33, 34 and 27 subjects in each group, respectively, completed the trial. Daily gum use of the XYL and MAL groups was 7.9 and 7.1 g, respectively. MS levels, which declined significantly in saliva (p < 0.05) and plaque (p < 0.001) in the XYL group after 6 months, exhibited a significant increase in plaque in the MAL group (p < 0.001). Differences in relative changes of MS levels in plaque during the experimental period were significant between the XYL group and the CR (p < 0.05) and MAL groups (p < 0.001). Differences in relative change of amount of plaque during the experimental period were not statistically significant between the groups. The present study demonstrated that chewing xylitol gum for 6 months continued to inhibit the growth of mutans streptococci in adults.

Pulmonary embolism: accuracy and safety of a negative CT pulmonary angiogram and value of a negative D-dimer assay to exclude CT pulmonary angiogram-detectable pulmonary embolism

This is a retrospective study to determine the accuracy and safety of a negative CT pulmonary angiogram (CTPA) based on clinical outcome and to determine the usefulness of a negative D-dimer assay before CTPA. A total of 483 patients with a negative CTPA study were followed up for 3 months, with the aim of detecting episodes of venous thromboembolism and mortality. Three hundred and forty-nine patients had an immunochromatographic D-dimer assay called 'Simplify', carried out before a CTPA examination. Seventy-eight patients had a negative D-dimer assay and a negative CTPA. Three patients had a negative D-dimer assay and a positive CTPA. All three patients had a moderate pretest clinical probability. Of the 483 patients who had a negative CTPA and a 3-month follow up, 444 (92%) were alive and 39 (8%) had died. Of the 444 patients who were alive, none had any further suspected episode of thromboembolism or had received anticoagulation therapy within the follow-up period. Of those who died, none of the deaths was thought to be as a result of pulmonary embolism (PE). Single-detector helical CT can be used safely as the primary diagnostic test to evaluate PE. Negative Simplify D-dimer assay and low pretest clinical probability exclude CTPA-detectable PE, and a CTPA is unnecessary in this cohort of patients.

Isolation and transplantation of highly purified autologous peripheral CD34+ progenitor cells: purging efficacy, hematopoietic reconstitution in non-Hodgkin's lymphoma (NHL): results of Japanese phase II study

The purging efficacy of positive selection of autologous CD34+ PBSC with a clinical scale method of magnetic-activated cell sorting system (CliniMACS) was investigated in 48 patients with non-Hodgkin's lymphoma (NHL). The median purity and recovery rate of the CD34+ cells post-selection were 93.3% (range 32.6-99.3) and 72.2% (range 20.5-309.8), respectively. The real-time PCR method to detect the patient-specific monoclonal immunoglobulin heavy chain gene rearrangement (minimal residual tumor; MRT) and CD19 and CD20 positivities were used for the detection of contaminating NHL cells before and after CD34+ selection. After selection, the median (range) depletion rate of MRT was 2.53 (1.52-4.78) log, and that of CD19+ cell and CD20+ cell was 2.46 (0.74-3.64) log and 2.32 (0.40-4.01) log, respectively. In 41 patients, high-dose chemotherapy was performed, followed by the transplantation of the isolated CD34+ cells. Rapid neutrophil recovery as well as platelet recovery was seen with a median time to reach 0.5 x 10(9)/l neutrophils of 10 days (range 8-13) and 20 x 10(9)/l platelets of 14 days (range 10-34), respectively. The present study demonstrated that CliniMACS is a highly effective positive selection method and a high purging efficacy could be obtained without compromising the hematopoietic reconstitution capacity of the graft in NHL patients undergoing high-dose chemotherapy.

Randomized phase II study of biweekly CHOP and dose-escalated CHOP with prophylactic use of lenograstim (glycosylated G-CSF) in aggressive non-Hodgkin's lymphoma: Japan Clinical Oncology Group Study 9505

BACKGROUND

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) is accepted as the best available standard treatment for first-line chemotherapy in aggressive non-Hodgkin's lymphoma (NHL). However, the therapeutic efficacy of CHOP remains unsatisfactory, particularly in high-intermediate risk and high risk patients, and a new strategy is warranted in this patient population. The aim of the present study was to explore a suitable therapeutic-intensified regimen for the treatment of aggressive NHL.

PATIENTS AND METHODS

Between May 1995 and July 1998, a total of 70 patients with high-intermediate risk or high risk aggressive NHL, according to the International Prognostic Index, were enrolled and randomly assigned to receive either eight cycles of standard CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 2 weeks, or six cycles of dose-escalated CHOP (cyclophosphamide 1500 mg/m(2), doxorubicin 70 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 3 weeks. Lenograstim (glycosylated rHuG-CSF), at a dose of 2 micro g/kg/day s.c., was administered daily from day 3 until day 13 with biweekly CHOP and until day 20 with the dose-escalated CHOP. The primary endpoint was complete response rate.

RESULTS

The complete response rate was 60% [21 of 35; 95% confidence interval (CI) 42% to 76%] with biweekly CHOP and 51% (18 of 35; 95% CI 34% to 69%) with dose-escalated CHOP. The major toxicity was grade 4 neutropenia and was more frequent in the dose-escalated CHOP arm (86%) than in the biweekly CHOP arm (50%). Grade 4 thrombocytopenia was also more frequent in the dose-escalated CHOP arm (20%) than the biweekly CHOP arm (3%). Non-hematological toxicities were acceptable in both arms. One treatment-related death (due to cardiac arrhythmia) was observed in a dose-escalated CHOP patient. Progression-free survival at 3 years was 43% (95% CI 27% to 59%) in the biweekly CHOP arm and 31% (95% CI 16% to 47%) in the dose-escalated CHOP arm. Although seven patients were deemed ineligible by central review of the pathological diagnosis, the results for both eligible and all enrolled patients were similar.

CONCLUSIONS

Similar complete response rates and progression-free survival rates, but lower toxicity, indicated that biweekly CHOP was superior to dose-escalated CHOP in the treatment of aggressive NHL. Based on these results, the Lymphoma Study Group of the Japan Clinical Oncology Group is conducting a randomized phase III study comparing biweekly CHOP with standard CHOP in newly diagnosed patients with advanced-stage aggressive NHL.

Geometry-dependent electrostatics near contact lines

Long-ranged electrostatic interactions in electrolytes modify contact angles on charged substrates in a scale and geometry-dependent manner. For angles measured at scales smaller than the typical Debye screening length, the wetting geometry near the contact line must be explicitly considered. Using variational and asymptotic methods, we derive new transcendental equations for the contact angle as functions of the electrostatic potential only at the three phase contact line. Analytic expressions are found in certain limits and compared with predictions for contact angles measured with lower resolution. An estimate for electrostatic contributions to line tension is also given.

[Multiple myeloma--advances in disease biology and implications for therapy]

Multiple myeloma (MM) is a systemic malignancy of pathologic plasma cells that is treatable with various chemotherapeutic agents and irradiation, but rarely curable. The mean age of affected patients is the mid-60s. Since the clinical presentation of multiple myeloma varies from asymptomatic to aggressive progression, there are many therapeutic options, such as follow-up without any treatment, and high-dose chemotherapy with stem cell transplantation. Recent advances in disease biology and implications for therapy are reviewed and summarized.

Timing of postoperative adjustment in adjustable suture strabismus surgery

PURPOSE

The use of adjustable sutures in strabismus surgery has increased the rate of surgical success. Little data are available on the optimum timing for postoperative adjustment after strabismus surgery. We wanted to compare 2 common practices of adjustable suture technique after strabismus surgery.

METHODS

Two comparable groups of 40 patients each, who had strabismus surgery with adjustable suture technique, were prospectively studied. Group A had early adjustment the same day of the surgery about 6 hours after the operation, and group B had late adjustment the next day about 24 hours after the operation. Subjective scoring tables were used to evaluate the pain felt by the patient before, during, and after the adjustment and any difficulties of the adjustment process. Requirements of postoperative pain medications and final alignment 6 weeks after surgery were also compared.

RESULTS

Despite adequate statistical power, no significant differences were found between the groups regarding pain before, during, and after adjustment, difficulties performing the adjustment, and final alignment after 6 weeks (P > .05). Both adjustment schedules were equally associated with mild to moderate pain before, during, and after the adjustment. In the first 24 hours after surgery, no overall difference in the use of pain medications was found. Nausea and vomiting in the first 24 postoperative hours were more common in the early adjustment group (P = .02).

CONCLUSION

The surgeon can feel free to choose the timing for postoperative adjustment. However, when performing an early adjustment, the surgeon should be especially prepared to control nausea and vomiting.

Surface-dependent coagulation enzymes. Flow kinetics of factor Xa generation on live cell membranes

The initial surface reactions of the extrinsic coagulation pathway on live cell membranes were examined under flow conditions. Generation of activated coagulation factor X (fXa) was measured on spherical monolayers of epithelial cells with a total surface area of 41-47 cm(2) expressing tissue factor (TF) at >25 fmol/cm(2). Concentrations of reactants and product were monitored as a function of time with radiolabeled proteins and a chromogenic substrate at resolutions of 2-8 s. At physiological concentrations of fVIIa and fX, the reaction rate was 3.05 +/- 0.75 fmol fXa/s/cm(2), independent of flux, and 10 times slower than that expected for collision-limited reactions. Rates were also independent of surface fVIIa concentrations within the range 0.6-25 fmol/cm(2). The transit time of fX activated on the reaction chamber was prolonged relative to transit times of nonreacting tracers or preformed fXa. Membrane reactions were modeled using a set of nonlinear kinetic equations and a lagged normal density curve to track the expected surface concentration of reactants for various hypothetical reaction mechanisms. The experimental results were theoretically predicted only when the models used a slow intermediate reaction step, consistent with surface diffusion. These results provide evidence that the transfer of substrate within the membrane is rate-limiting in the kinetic mechanisms leading to initiation of blood coagulation by the TF pathway.

Statistical thermodynamics of membrane bending-mediated protein-protein attractions

Highly wedge-shaped integral membrane proteins, or membrane-adsorbed proteins can induce long-ranged deformations. The strain in the surrounding bilayer creates relatively long-ranged forces that contribute to interactions with nearby proteins. In contrast, to direct short-ranged interactions such as van der Waal's, hydrophobic, or electrostatic interactions, both local membrane Gaussian curvature and protein ellipticity can induce forces acting at distances of up to a few times their typical radii. These forces can be attractive or repulsive, depending on the proteins' shape, height, contact angle with the bilayer, and a pre-existing local membrane curvature. Although interaction energies are not pairwise additive, for sufficiently low protein density, thermodynamic properties depend only upon pair interactions. Here, we compute pair interaction potentials and entropic contributions to the two-dimensional osmotic pressure of a collection of noncircular proteins. For flat membranes, bending rigidities of approximately 100k(B)T, moderate ellipticities, and large contact angle proteins, we find thermally averaged attractive interactions of order k(B)T. These interactions may play an important role in the intermediate stages of protein aggregation. Numerous biological processes where membrane bending-mediated interactions may be relevant are cited, and possible experiments are discussed.

A single amino acid of the human and rat neurotensin receptors (subtype 1) determining the pharmacological profile of a species-selective neurotensin agonist

The neurotensin (NT) receptor, subtype 1 (NTR1), is a 7-transmembrane-spanning receptor, forming 3 extracellular and 3 intracellular loops. Previously, we showed that the third outer loop (E3) is the binding site for NT and its analogs, several of which bind with higher affinity to rat NTR1 (rNTR1) than to human NTR1 (hNTR1). In particular, NT34 [3,1'-naphthyl-l-Ala(11)]NT(8-13) has greater than 60-fold higher affinity for rNTR1 (46 and 60 pM for transiently- and stably-transfected cells, respectively) than for hNTR1 (2.8 and 5.8 nM for transiently- and stably-transfected cells, respectively) isolated from transfected cell membranes. Previously, our molecular modeling studies of rNTR1 and hNTR1 showed that the binding pocket in the human receptor for NT34 is smaller in volume from the bulky residue Tyr(339) in the pocket center, as compared with the corresponding residue Phe(344) in the rat binding pocket. Therefore, with site-directed mutagenesis, we derived mutant forms of rNTR1(F344Y) and hNTR1(Y339F). Examination of the mutant receptors from membranal preparations of transfected cells in radioligand binding assays and with intact cells in functional assays (phosphatidyl-4,5-bisphosphate turnover) showed that the human-like rat receptor and the rat-like human receptor bound NT34 with a predicted reverse of binding compared with its binding to the wild-type receptors. These results strongly affirm our molecular modeling studies and demonstrate the importance of the study of even minor structural variations in proteins to determine the basis of significantly different drug responses, an area of focus for pharmacological research in the 21st century.

Randomized comparison of mobilization kinetics of circulating CD34+ cells between biweekly CHOP and dose-escalated CHOP with the prophylactic use of lenograstim (glycosylated rHuG-CSF) in aggressive non-Hodgkin's lymphoma. The lenograstim/Lymphoma Study Group

High-dose chemotherapy with autologous hematopoietic stem cell transplantation has been expected to result in a promising outcome in high risk aggressive non-Hodgkin's lymphoma (NHL). However, it remains unknown what type of initial chemotherapy is optimal, especially regarding progenitor cell mobilization. Sixty-three untreated patients with aggressive NHL in a high risk group were randomized to either a biweekly arm with 8 cycles of standard CHOP or 6 cycles of the dose-escalated CHOP arm with cyclophosphamide 1.5 g/m2 and doxorubicin 70 mg/m2. Lenograstim (glycosylated rHuG-CSF 2.0 microg/kg/day) was administered daily from day 3 to patients in both arms. The mobilization effect of the two regimens on circulating CD34+ cells was evaluated. Twenty-seven of 29 patients in the biweekly CHOP arm and 33 of 34 patients in the dose-escalated CHOP were assessable. Dose-escalated CHOP yielded a significantly higher number of circulating CD34+ cells in the first cycle compared with biweekly CHOP (p=0.05). The peak number of circulating CD34+ cells with biweekly CHOP did not significantly change from cycle to cycle; however, in dose-escalated CHOP, the peak number of circulating CD34+ cells mobilized after the fifth and sixth cycle was lower than after the first cycle (p=0.07 and 0.009, respectively). Routine conventional-dose chemotherapy and low-dose G-CSF can mobilize sufficient CD34+ cells in patients with aggressive NHL. The mobilization kinetics of circulating progenitor cells in patients with aggressive NHL is dependent on the dosage and schedule of CHOP.

Utility of blasts with a clear halo around the nucleolus as a predictive indicator for disease progression in patients with myelodysplastic syndromes and aplastic anemia

This study was designed to evaluate the utility of blasts with a clear halo around their nucleoli (BCHN) as a predictive indicator of disease progression in myelodysplastic syndromes (MDSs) and aplastic anemia (AA). Bone marrow aspirates from 75 patients with MDSs and 18 with AA were fixed in 95% ethanol solution or 10% neutral formalin and stained with the Papanicolaou method. BCHNs were detected in 57 of 75 patients with MDSs and in 10 of 18 AA patients. Disease progression was restrictedly observed in 17 patients with MDSs who had BCHNs at onset and in 1 patient with AA. The proportion of BCHNs increased with disease progression in these 16 of 17 patients with MDSs. The presence of BCHNs at onset and the increase in proportion of BCHNs during the clinical course of MDSs were significant indications for predicting disease progression.

Analysis of binding sites and efficacy of a species-specific peptide at rat and human neurotensin receptors

We have developed a neurotensin analog, L-[3,1'-naphthylalanine11]NT(8-13), NT34, that can distinguish between rat and human neurotensin receptors, and exhibits more than a 100-fold difference in binding affinities and a 60-fold difference in functional coupling to phosphatidylinositol turnover. Using cells transfected with different numbers of the appropriate receptors, we measured the changes in phosphatidylinositol production, and then evaluated the efficiency of receptor-effector coupling based on Furchgott's design. The binding of NT34 at both rat and human neurotensin receptors stably expressed in CHO-K1 cells was to two sites, while the binding of NT was to one site. At the rat receptor the equilibrium dissociation constant (Kd) for NT34 at the high-affinity site was 0.058 nM, while that at the low-affinity site was 3.1 nM. For the human receptor at the high-affinity site, the Kd for NT34 was 18 nM, while that at the low-affinity site was 180 nM. For both species the percentage of receptors representing the high-affinity site was approximately 60-70% with 30-40% at the low-affinity site. We derived agonist dissociation constants (Ka) for NT and NT34, which suggest that for NT34, the low-affinity site is functionally coupled to phosphatidylinositol turnover. Finally, we compared the relative efficacies of both compounds and found that NT34 was about 2-fold and 4-fold more efficacious than NT in stimulating phosphatidylinositol turnover in rat and human NT receptors, respectively.

[A multicenter early phase II study of high-dose chemotherapy with autologous peripheral blood stem cell transplantation for treatment of intermediate-grade non-Hodgkin's lymphoma. Japan Blood Cell Transplantation Study Group]

We conducted a multicenter early phase II study to evaluate the feasibility and therapeutic efficacy of high-dose chemotherapy supported by autologous peripheral blood stem cell transplantation (auto-PBSCT) for the treatment of intermediate grade non-Hodgkin's lymphoma (IG-NHL). High-dose etoposide or cyclophosphamide followed by G-CSF was used for PBSC mobilization, and a sufficient number of CD34+ cells (> 1 x 10(6)/kg) were collected. Out of 81 enrolled patients, 50 received high-dose chemotherapy with auto-PBSCT; Hematologic recovery after transplantation was rapid. The incidence of grade III/IV toxicity (Bearman) was about 6%; treatment-related mortality was 6% (3/50). The Disease-free survival rate for the patients in complete remission who received high-dose chemotherapy with auto-PBSCT was better than that for the patients who were treated with conventional chemotherapy (57% vs 35%). These preliminary results indicated that high-dose chemotherapy with auto-PBSCT is feasible and effective. A prospective randomized phase III clinical trial will be required to assess the efficacy of high-dose chemotherapy with auto-PBSCT as a post-remission therapy for IG-NHL.

Emerging infectious diseases and pathogens

Emerging infectious diseases are caused by old, new, and mutant microorganisms. Emergence of these pathogens can be attributed to changes in the characteristics and risk factors of patients, the widespread use of antibiotics, changes in the environment, the role of xenotransplantation, and international travel. In the United States, the incidences of C. difficile, cyclosporiasis, enterohemorrhagic E. coli gastroenteritis, Hantavirus, hepatitis C virus infection, and Lyme disease have increased significantly over the past two decades. Malassezia pachydermatis, extended spectrum beta lactamase (ESBL), Gram negative bacilli, and antibiotic resistant Enterococci, S. aureus, S. pneumoniae, and M. tuberculosis have also emerged prominently. Although not yet seen in the United States, variant Creutzfeldt-Jakob disease has made a great emotional impact on this country. Identifying, treating, and controlling emerging infectious disease and pathogens have created enormous challenges.

A dose-finding study of lenograstim (glycosylated rHuG-CSF) for peripheral blood stem cell mobilization during postoperative adjuvant chemotherapy in patients with breast cancer. Lenograstim/Breast Cancer Study Group

BACKGROUND

The optimum dose of granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell (PBSC) mobilization after disease-oriented, conventional-dose chemotherapy remains unknown.

METHODS

A multicenter dose-finding study of glycosylated G-CSF (lenograstim) for the mobilization of PBSCs following adjuvant CAF chemotherapy (cyclophosphamide, doxorubicin and 5-fluorouracil) was performed in 38 patients with postoperative breast cancer. Each 10, ten and eight patients were sequentially allocated to one of the three dose groups (2, 5 and 10 micrograms/kg, respectively) of lenograstim. Lenograstim was administered subcutaneously (s.c.) daily from day 8 to the day of the last apheresis and CD34+ cells and colony-forming units-granulocyte macrophage (CFU-GMs) in peripheral blood were measured serially. Additionally, 10 patients who received adjuvant CAF chemotherapy alone also participated in the study, as a control.

RESULTS

Lenograstim was well tolerated up to 10 micrograms/kg, except for one patient given 10 micrograms/kg who developed transient grade 3 hepatic enzyme elevation. The peak levels of CD34+ cells and CFU-GMs in peripheral blood showed dose-response relationships. The median peak CD34+ cells for the 0, 2, 5 and 10 micrograms/kg dose groups were 5.4, 34.3, 55.0 and 127.6 cells/microliter, respectively, and those of CFU-GMs for the 0, 2, 5 and 10 micrograms/kg dose groups were 0.01, 0.33, 1.32 and 3.30 CFU-GMs/microliter, respectively.

CONCLUSIONS

Considering the previous reports suggesting that a pre-apheresis number of 40-50 CD34+ cells/microliter in peripheral blood is highly predictive for achievement of more than 2.5 x 10(6) CD34+ cells/kg in a standard apheresis procedure of 10 litres, the optimum dose of lenograstim for PBSC mobilization following CAF chemotherapy in patients with postoperative breast cancer is 5 micrograms/kg/day s.c.

An outbreak of bloodstream infections arising from hemodialysis equipment

An outbreak of 29 cases of bloodstream infection by 16 pathogens occurred during 8 months at two chronic hemodialysis centers. Consequences included 21 hospital admissions and removal of 23 dialysis catheters. An epidemiologic investigation comparing case-patients with uninfected controls showed that risk was significantly (P < .05) associated with having a catheter for vascular access; receiving treatment on a Monday, Wednesday, Friday schedule; and receiving treatment on one heavily contaminated dialysis machine. Culture studies and mock trials showed that bloodstream pathogens were present in a recently installed, commercially marketed attachment for disposal of spent priming saline and could enter blood line tubing directly or indirectly during dialyzer priming and tubing assembly. The outbreak was halted by measures directed at the attachment. Investigation of this problem demonstrated that microbial overgrowth in the attachment caused bloodstream infections and underscores the importance of microbiologic considerations in the design and use of hemodialysis equipment.

Proportion of blasts with a clear halo around nucleoli at the end of induction therapy of acute myeloid leukemia correlates with achievement of complete remission, remission duration and relapse

Bone marrow aspirates from 60 patients with acute myeloid leukemia (AML) were investigated using 95% ethanol fixation Papanicolaou stained preparations. The blasts were grouped into those with a clear halo around nucleoli (BCHN) and those without a clear halo. The patients were classified into three groups according to the degree of persistent BCHN at the end of induction therapy: group 1, no BCHN; group 2, less than 1% BCHN; and group 3, 1% or more BCHN. All patients in groups 1 (17 cases) and 2 (12 cases), and 12 of 31 cases in group 3 achieved complete remission (CR). Of 17 patients in group 1, two underwent bone marrow transplantation and two died from infection. Of the 37 patients who achieved CR, relapse was observed in two of 13 patients in group 1, and in all patients in groups 2 and 3. As to the patients treated with N4-behenoyl-1-beta-D-arabinofuranosyl-cytosine + daunorubicin + 6-mercaptopurine + prednisolone (BHAC-DMP) protocol, the percentages and number of BCHN at the diagnosis of AML in group 1 were significantly lower than those of groups 2 and 3. The percentage and number of BCHN at the diagnosis of AML were significant factors for the achievement of CR and for the prediction of long-term outcome. The reduction of BCHN to less than 1% at the end of induction therapy is a good indicator for the achievement of CR, and the disappearance of BCHN is a useful target for a long-lasting first CR; conversely, the persistence of BCHN is a major adverse factor for relapse.