Retrospective review of DPACE therapy for aggressive, refractory multiple myeloma (MM)

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Background: Oral dexamethasone ± thalidomide with a 4-day infusion of cisplatin, doxorubicin, cyclophosphamide, and etoposide (DPACE) is an effective induction therapy prior to transplant in patients (pts) with MM. Limited experience also suggests DPACE may reduce disease burden as a salvage regimen for aggressive, refractory MM. Methods: We performed a retrospective review from 1999- 2005 of all MM pts who received DPACE ± thalidomide as a salvage regimen at our center. Results: A total of 39 pts received DPACE at a median 23 mos from diagnosis (range, 10–84). Median age was 53 years (34–70), 51% stage 3 at diagnosis. Plasma cell leukemia had developed in 12 pts and leptomeningeal disease in 4 pts at time of DPACE. Ten of 24 pts (42%) with cytogenetics had del 13q. Pts were heavily pretreated (median 3 prior regimens; prior autotransplant [ASCT] 38%; thalidomide 64%; and bortezomib 10%). Pts received 1–4 cycles as tolerated for refractory (83%) or relapsed (17%) disease. Thalidomide was used in 41% of cycles. Hematologic toxicity was common (grade 3–4 neutropenia 92% and thrombocytopenia 72%). Although G-CSF was used in 71% of cycles, febrile neutropenia was common (53%) and 26% required hospitalization. Overall RR was 36% (14 pts: PR 12, VGPR 2). An additional 8% achieved MR, 23% SD. PD occurred in 15% and 18% died on therapy (4 progressive MM; 2 neutropenic sepsis, 1 GI bleed). No prior ASCT (p=0.04) and <4 prior regimens (p=0.04) predicted for response to DPACE. Eleven pts proceeded to ASCT and one pt to a clinical trial with lenalidomide with a median OS from DPACE of 24.7 mos (95% CI, 11.2–63.6). Those who did not bridge to transplant or trial (n=27) had a short median PFS of 3.0 months (95% CI, 1.2–5.5) and OS of 6.7 mos (95% CI, 1.8–9.7). OS for all 39 pts was 8.7 mos (95% CI, 6.4–12.4). Conclusion: DPACE may be effective salvage therapy for heavily pretreated MM pts. Although the RR of 36% in this poor prognosis cohort is reasonable, the PFS is short and suggests that the best role for this regimen is in bridging to more definitive therapy such as transplantation.

[Table: see text]

Bortezomib is active in Waldenstrom’s Macroglobulinemia (WM)—Results of a National Cancer Institute of Canada (NCIC) phase II study in previously untreated or treated WM

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Background: WM is a B cell lymphoma characterized by a serum monoclonal IgM and marrow infiltration by lymphoplasmacytoid cells. Bortezomib is a proteasome inhibitor active in myeloma and other hematologic malignancies. In this 2-stage study, 27 WM pts received single agent bortezomib with RR as primary endpoint. Methods: Eligibility: symptomatic WM (Hb <110 g/L; lymphadenopathy; organomegaly; or hyperviscosity); ≤2 prior chemo regimens (± rituximab). Bortezomib 1.3 mg/m2 IV given d1, 4, 8, 11 on a 21d cycle until PD or 2 cycles beyond CR/SD. Nodal disease was included in response criteria (2nd International WM Workshop). Results: Median age 65 (46–87), M:F 14:13, no prior therapy 11 (44%). At entry, median IgM 38 g/L (11.2–83.3); median Hb 108 g/L (63–142); 18 (66%) with nodal disease on CT. At a median of 6 cycles (2–35), 11/27 (41%) patients had ≥50% decrease in IgM alone plus 10 (37%) minor responses (25–49% decrease). Using IgM + nodal criteria: 1 CR, 5 PR (≥50% decrease in IgM and bidimensional disease), 20 SD, 1 PD = overall RR 22% (95% CI 8.6–42.2%). IgM responses were prompt (median 2 cycles; range 1–8) with nodal responses lagging (median 4 cycles). Hb increased by ≥10g/L in 18 pts (66%). Bortezomib was well-tolerated with most non-hematologic toxicities Gr 1–2: fatigue (74%), nausea (63%), myalgias (51%), non-neutropenic infections (48%), diarrhea (44%), constipation (44%). 18 pts (66%) developed neuropathy (sensory): typical onset 2–4 cycles; Gr 3 in 5 pts; 15/18 (83%) improving ≥1 grade (11 complete) in 2–13 mo. Gr 3 myalgias in 2 pts resolved in <1 mo. Gr 3–4 thrombocytopenia (30%) and neutropenia (18%) led to 12 missed doses, 1 dose reduction. Conclusions: Bortezomib is active in WM with 78% pts with ≥25% fall in IgM, 41% with IgM response criteria of ≥50% decrease, 22% with composite nodal/IgM responses. Despite prompt IgM and hematologic improvement, decrease in nodal disease is slow, reflected in overall responses lower than IgM alone. Although bortezomib is generally well-tolerated, neuropathy is common but reversible. Bortezomib combinations with conventional cytotoxic or targeted agents warrant further study in WM. This is a NCIC CTG study with a grant from NCIC and funds from Canadian Cancer Society.

[Table: see text]

Sequential, cycling maintenance therapy for post transplant multiple myeloma

High-dose chemotherapy with autologous stem cell transplantation in patients with newly diagnosed multiple myeloma can prolong survival but is not curative. Maintenance therapy post transplant may prolong the disease-free interval and impact overall survival. We have conducted a phase II pilot study of 28 post transplant myeloma patients treated with a sequential, cycling maintenance regimen. The regimen was designed to include a variety of active myeloma agents chosen for ease of administration to enhance patient compliance and scheduled sequentially to minimize toxicity. The 12-month cycling schedule included dexamethasone (months 1-3); melphalan and prednisone (months 4, 5); cyclophosphamide and prednisone (months 6, 7); alpha-interferon (months 8-10); followed by a drug holiday (months 11, 12). The regimen was generally well tolerated with five patients developing reversible grade III-IV toxicity (diabetes-induced hyperglycemia in four, neutropenia in one). There was one toxic death on study due to non-neutropenic pneumonia and sepsis. Median event-free survival from transplant was 36.9 months (95% CI 23.6 - upper limit not yet reached) with median overall survival not yet reached at a median follow-up of 44 months. This concept of cycling, sequential maintenance with various agents, perhaps including newer biological, targeted agents, warrants further investigation in multiple myeloma.

Treatment for Waldenstrom’s macroglobulinemia

Waldenstrom's macroglobulinemia is a rare form of indolent lymphoma characterized by the production of a monoclonal immunoglobulin M protein, and complications such as hyperviscosity, cytopenias and peripheral neuropathy. Conventional treatment approaches are based on alkylators or nucleoside analogs, but in the absence of a clearly superior regimen, a broad array of alternative therapies exists. Choices range from biological agents to combination chemotherapy to stem-cell transplantation. A rational approach therefore must be based on careful patient assessment and individualization of therapy.

Intermediate dose thalidomide (200 mg daily) has comparable efficacy and less toxicity than higher doses in relapsed multiple myeloma

Thalidomide at doses >200 mg has 100% grade 1-2 and 25% grade 3-4 toxicities requiring discontinuation. We report a retrospective study of relapsed myeloma patients treated with thalidomide 200 mg with no dose escalation. Thirty patients were identified; 43% of patients responded with paraprotein decline >75% -- 2 (6%), 50-75% -- 7 (23%), 25-50% -- 4 (14%) and 2 (6%) were stable. All five patients with 13q deletion responded. Only 54% reported grade 1-2 toxicities (none reporting > grade 2) with 5 (17%) discontinuing treatment due to toxicity. Thalidomide 200 mg daily with no dose escalation appears as effective and better tolerated than escalated doses for relapsed myeloma patients.

'Relative' chemotherapy sensitivity: the impact of number of salvage regimens prior to autologous stem cell transplant for relapsed and refractory aggressive non-Hodgkin's lymphoma

The purpose of the study was to assess the impact of number of salvage regimens needed to demonstrate chemotherapy sensitivity on relapse rates, survival, and toxicity following high-dose therapy and autologous bone marrow transplantation (ABMT) in relapsed or refractory non-Hodgkin's lymphoma. We retrospectively reviewed 136 patients with intermediate-grade lymphoma who underwent ABMT. All patients were treated with salvage therapy to maximum tumor reduction. Three quarters (102/136) of the patients received one salvage regimen, while 31 (23%) patients received two or more regimens. When compared to patients requiring >or= two regimens, patients requiring only one salvage regimen to demonstrate chemosensitivity were more likely to have a longer previous CR from initial therapy (CR >or=12 months in 47% vs 26%; P = 0.04) and to have attained CR with salvage (54% vs 16%; P = 0.001). Both median relapse-free survival (RFS) and overall survival (OS) have not yet been reached in patients receiving one salvage regimen (median follow-up 50.6 months). This is superior to the median RFS of 9.1 months (P = 0.004) and OS of 11.1 months in patients requiring >or=two regimens to demonstrate chemosensitivity (P = 0.002). Time to engraftment, toxic deaths and incidence of myelodysplasia were similar in the groups. The survival rate observed in patients requiring >or=two salvage regimens, although inferior to that of patients receiving a single salvage regimen, are still generally superior to results in the literature for patients treated with chemotherapy alone without ABMT. We conclude that high-dose therapy with ABMT is appropriate for lymphoma patients even when disease reduction requires repeated numbers of salvage regimens.

Selective termination of aneuploidy utilizing rapid fluorescence in situ hybridization detection techniques

Twin pregnancy following assisted reproductive technology with a euploid fetus and a coexisting aneuploid co-twin constitutes a conflicting situation; therefore, it is important for the genetic constitution of each co-twin to be diagnosed accurately and promptly for parental genetic counseling and subsequent aggressive management. A 35-year-old woman, gravida 1, with a 2-year history of infertility, presented bilateral fallopian tubal obstruction at her infertility workups, for which she received in vitro fertilization; subsequently she conceived a twin pregnancy. She underwent genetic amniocentesis at 16 weeks' gestation, as indicated by an advanced maternal age. Presented with the diagnosis of twin pregnancy with discordancy for trisomy 21, a rapid fluorescence in situ hybridization (FISH) technique for aneuploidy mapping was applied for subsequent abdominal selective fetal reduction. The FISH technique facilitates the rapid analysis of uncultured amniocytes. Normal (disomic) and trisomic samples can be distinguished clearly and rapidly for subsequent selective fetocide. The FISH technique is an important tool in prenatal diagnosis and clinical applications.

Autotransplants for histologically transformed follicular non-Hodgkin's lymphoma

Histological transformation from a follicular non-Hodgkin's lymphoma (NHL) to a higher grade lymphoma carries a poor prognosis despite treatment with aggressive anthracycline-based chemotherapy. We retrospectively analysed 35 patients with histologically transformed NHL who underwent high-dose therapy and autotransplantation at our centre. Patients up to 65 years old were eligible for autotransplant at the time of transformation or with subsequent relapses, provided that chemosensitivity to a salvage regimen could be demonstrated. All patients received high-dose therapy [etoposide 60 mg/kg, melphalan 160 mg/m2 and fractionated total body irradiation (TBI) 12 Gy] followed by unpurged autologous bone marrow or blood stem cell rescue. Most patients (69%) had advanced stage disease (stages 3--4) at transformation and bone marrow involvement was common (49%). Twenty-six (74%) patients were in partial remission (PR) and nine (26%) in complete remission (CR) at the time of transplant. Median duration from transformation to transplant was 10.9 months (range, 5.2 months--4.6 years). At a median follow up of 52 months after autotransplant, 19 (54%) patients had died. Causes of death were progressive lymphoma in nine patients (26%), treatment-related mortality (TRM) in seven (20%) and myelodysplasia in three (8%). Only five patients in our cohort were > 60 years old, but all died as a result of treatment-related causes (mostly pulmonary infections). Five-year overall survival and progression-free survival from time of transplant were 37% and 36% respectively. Using multivariate analysis of factors including gender, age, stage, extranodal disease, disease bulk, B symptoms, number of prior therapies, relapse status and CR/PR status at transplant, only advanced age significantly predicted for survival from autotransplant (P = 0.002). Our survival data are comparable to previous reports of autotransplantation for transformed NHL and suggest a benefit over standard chemotherapy alone in selected patients. However, our high TRM cautions the use of aggressive therapy, including TBI, in patients over 60 years old.

Radiation-associated pneumonitis following autologous stem cell transplantation: predictive factors, disease characteristics and treatment outcomes

High-dose therapy followed by autologous stem cell transplantation (ASCT) prolongs survival in patients with multiple myeloma and is relatively safe with treatment-related mortality rates of only 1-5%. Interstitial pneumonitis (IP) is normally an infrequent complication of ASCT with a reported incidence of 0-16%. Between 1992 and 1998, 94 myeloma patients at our center underwent ASCT using a high-dose regimen of etoposide (60 mg/kg), melphalan (160 mg/m2) and fractionated TBI 12 Gy. An unusually high incidence of IP (29/94 (31%)) was noted. Mortality in the IP patients was high at 45%. Patients developing IP were more frequently anemic than those who did not have pulmonary complications (hemoglobin <100 g/l) prior to transplant (P = 0.03) but no other pre-transplant factors were predictive (ie age, gender, smoking history, CMV status, pulmonary function, creatinine, beta2-microglobulin or C-reactive protein, prior cumulative chemotherapy or chest irradiation). A significantly lower IP rate was noted in 32 contemporaneous myeloma control patients conditioned with BU-CY without TBI at our center (3/32 (9%); P=0.03) and in 32 lymphoma control patients conditioned with the same melphalan and etoposide regimen minus the TBI (2/32 (6%); P = 0.003). In contrast, when using the same TBI-containing regimen in 32 concurrently treated lymphoma patients, an increase in IP similar to that seen in our myeloma cohort (7/32 (22%); P = 0.3) was noted. This strongly suggests that TBI is the predominant factor contributing to lung toxicity. We conclude that radiation-associated pneumonitis cannot be easily predicted by pretransplant variables. Therefore surveillance, early recognition and prompt therapy are recommended.

A comparison of elderly patients with aggressive histology lymphoma who were entered or not entered on to a randomized phase II trial

The purpose of this study was to compare the baseline patient characteristics, treatments and outcomes of elderly patients with aggressive histology lymphoma who were entered or not entered onto a randomized phase II trial. We previously conducted a randomized phase II trial in patients > or = 65 years of age who had advanced stage intermediate grade lymphoma. A registry of all patients meeting the inclusion criteria for that trial was maintained. Many patients were not entered on to the randomized trial because of the presence of at least one exclusion criterion, or because of patient or physician choice. We have compared the baseline characteristics, treatment, and survival of the randomized and non-randomized patients. Results show that 68 consecutive patients met inclusion criteria for the randomized trial. Thirty-eight patients satisfied all eligibility criteria, consented, and were randomized; 30 patients (44%) were not entered. In comparison with randomized patients, non-randomized patients were older (mean 75.9 vs. 72.4 years; P=0.013), had a poorer performance status (P=0.0006), were less likely to be given treatment with curative intent (60% vs. 100%; P<0.001), and were less likely to complete 6 cycles of such treatment (27% vs. 89%; P<0.001). With a median follow-up of > 7 years, actuarial 5-year survival is superior in randomized patients (44.3% vs. 10%; P<0.00001). In conclusion, a substantial number of patients did not enter our randomized trial phase II trial and had different characteristics, received different therapy and had inferior outcomes in comparison with randomized patients. Randomized trials of therapy for elderly lymphoma patients may include special selection criteria and results may not be generalizable to a substantial proportion of other older patients.

Birth after the injection of sperm and the cytoplasm of tripronucleate zygotes into metaphase II oocytes in patients with repeated implantation failure after assisted fertilization procedures

OBJECTIVE

To assess the technique of injecting a single sperm and cytoplasm obtained from tripronucleate zygotes into metaphase II oocytes for the treatment of patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

DESIGN

Clinical study.

SETTING

Private infertility clinic.

PATIENT(S)

Patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

INTERVENTION(S)

The metaphase II oocytes of recipients were injected with their husbands' spermatozoa and cytoplasm aspirated from the tripronucleate zygotes of donors.

MAIN OUTCOME MEASURE(S)

Fertilization after cytoplasm and sperm injection, embryo development, and successful pregnancy.

RESULT(S)

In total, 62 metaphase II oocytes from nine recipients were injected. Of the 62 injected oocytes, 3 (5%) degenerated and 43 (69%) had two pronuclei 18 hours after injection. Thirty-nine oocytes with two pronuclei cleaved to the two-cell to six-cell stage after another 24 hours of culture. All cleaved embryos were transferred into the uteruses of recipients. Four clinical pregnancies occurred in four recipients. No abnormal chromosomes were observed after amniocentesis and karyotyping in all pregnancies. Five healthy infants were born.

CONCLUSION(S)

Injection of the cytoplasm of tripronucleate zygotes may enhance the clinical pregnancy rate in patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

Early alteration of coronary hemodynamics in late restenosis after coronary angioplasty

It is not known whether changes in coronary hemodynamics may antedate the development of restenosis after percutaneous coronary transluminal angioplasty (PTCA). The purpose of this study was to evaluate the early change in coronary microvascular function in patients with late restenosis after PTCA. Coronary hemodynamics were studied in series before, immediately after, 2 weeks and 3 months after successful PTCA in 12 male patients with a single lesion of the left anterior descending coronary artery. In each patient, great cardiac venous flow (GCVF) and oxygen content were measured both at baseline and during hyperemia induced by adenosine infusion. The sequential changes of coronary hemodynamics were compared between patients with and without restenosis at 3 months after PTCA. Basic characteristics did not differ between the patients with (n = 6) and those without restenosis (n = 6). Luminal diameter stenosis (in percentage) was also similar between the two groups both before (79.2 +/- 18.4% vs 83.0 +/- 9.6%, p = NS) and up to 2 weeks after PTCA (25.8 +/- 10.9% vs 28.5 +/- 7.9%, p = NS). In patients without restenosis, basal and hyperemic GCVF was unchanged up to 2 weeks after PTCA. There was a significant increase in CFR 3 months after PTCA. In patients with restenosis, basal GCVF was significantly increased and hyperemic GCVF was unchanged immediately after PTCA. However, 2 weeks after PTCA, basal GCVF was decreased while luminal diameter was still preserved. In comparison with those without restenosis, patients with restenosis had significantly lower CFR before (1.98 +/- 0.42 vs 2.69 +/- 0.46, p = 0.019), immediately after (1.47 +/- 0.27 vs 2.24 +/- 0.47, p = 0.006) and 3 months after PTCA (1.51 +/- 0.32 vs 3.40 +/- 0.54, p = 0.001). In patients without restenosis, the recovery of coronary microvascular function was delayed up to 3 months after PTCA. In patients with late restenosis, basal coronary microvascular tone was altered within 2 weeks after PTCA suggesting early deterioration of coronary microvascular function before the development of angiographic restenosis.

Natural mass infection by heterophyid metacercariae in aquacultured Japanese eel in Taiwan

A natural mass infection of heterophyid metacercariae in aquacultured Japanese eel Anguilla japonica in Taiwan was observed. Of the 28,000 adult eels in 2 ponds, about 25,000 (90%) showed swollen, cloudy and white eyes. Although morbidity was about 90%, there was no mortality among the affected eels. Histopathological sections showed edema and hemorrhage of the eye. Numerous metacercariae were observed in the muscle tissues around the eyeball, the subcutaneous tissue and even in the cartilage. Of the 6 eels digested with artificial gastric juice, all were found to contain metacercariae in their muscle tissues. The average number of metacercariae recovered from the 6 eels was 1219, with a range of 50 to 3762. These metacercariae, when fed orally to immunodeficient (scid) mice, developed into adult worms which were identified as Procerovum cheni Hsu 1950. The naturally infected eels were transferred to a new pond without snails and their eye lesions were not apparent anymore after 2 wk. In a follow-up investigation, 19 of 20 apparently healthy eels in a nearby aquaculture farm were found to harbour metacercariae in their muscles. However, the number of the metacercariae ranged from 1 to 14, with an average of 4.21. This is the first report of heterophyid metacercariae causing mass morbidity in aquacultured eels.

Studies of multimerin in patients with von Willebrand disease and platelet von Willebrand factor deficiency

In normal platelet alpha-granules von Willebrand factor (VWF) is stored with multimerin and factor V in an eccentric electron-lucent zone. Because the platelet stores of VWF are deficient in 'platelet low' type 1 and type 3 von Willebrand disease (VWD), we investigated their electron-lucent zone proteins. The patients with VWD had partial to complete deficiencies of plasma and platelet VWF but normal alpha-granular multimerin and factor V, and normal alpha-granular fibrinogen, thrombospondin-1, fibronectin, osteonectin and P-selectin. In type 3 VWD platelets, alpha-granular electron-lucent zones lacking VWF-associated tubules were identified and multimerin was found in its normal alpha-granular location. These findings indicate that the formation of the electron-lucent zone and the sorting of multimerin to this region occur independent of VWE The isolated abnormalities in VWF suggests a VWF gene mutation is the cause of 'platelet low' type 1 VWD.

Metacercariae in fishes of Sun Moon lake which is an endemic area for Clonorchis sinensis in Taiwan

The Sun Moon lake in Central Taiwan is a known endemic area for clonorchiasis. Of the 45 fresh water fish, Hemiculter leucisculus, from the lake that were examined by artificial gastric juice digestion in October 1995, all were found to harbor metacercariae in their muscle. The number of metacercariae isolated from each fish ranged from 2 to 2,185, with an average of 254. A total of 11,443 metacercariae was collected from the 45 fish. Of the 4,223 metacercaria that were examined under light microscope, 4,064 (96.23%) were found to belong to Haplorchis taichui, 90(2.13%) to H. pumilio, 2(0.05%) to C. sinensis and 67 (1.59%) to unknown species due to the metacercariae being not yet developed or immature. The 2 C. sinensis metacercariae were obtained from 2 out of 45 fish examined. Our results contrast with reports of a decade ago which stated that all the fish of the Sun Moon lake examined were positive for C. sinensis. Possible reasons for the decrease of C. sinensis metacercariae are the disappearance of pig farms around the lake, increased awareness of the trematode by the lakeside inhabitants and probably the exclusive use of mammals as its definitive host by C. sinensis. In contrast, besides mammals, Haplorchis spp also use birds as their definitive hosts.

A high-performance double-crystal monochromator soft X-ray beamline

A high-performance double-crystal-monochromator soft X-ray (DCMSX) beamline has been constructed at the Synchrotron Radiation Research Center (SRRC). This beamline delivers monochromatic photon beams with energies from 1 to 9 keV and a resolving power (E/DeltaE) of up to 7000. This beamline provides users with an opportunity to study many important materials, such as high-T(c) superconductors, magnetic materials, catalysts, super-alloy compounds etc. Excellent EXAFS and NEXFS spectra have been routinely obtained from this beamline. Several interesting research projects are currently being conducted at this beamline. All the results show that this beamline has been constructed to meet its design goals.

New stenosis on proximal coronary segment after directional atherectomy. Two case reports

Two patients with new coronary stenotic lesions subsequently developed proximal to the sites accepting directional coronary atherectomy (DCA) are reported. One lesion developed at the left main coronary artery and the other at the proximal segment of the left anterior descending artery. The mechanisms of the development of such new stenotic lesions after DCA were studied and procedure-related mechanical trauma over the proximal segment of the primary lesion may be the possible mechanism for such complication.

Thermophilic biodegradation of BTEX by two consortia of anaerobic bacteria

Two thermophilic anaerobic bacterial consortia (ALK-1 and LLNL-1), capable of degrading the aromatic fuel hydrocarbons, benzene, toluene, ethylbenzene, and the xylenes (BTEX compounds), were developed at 60 degrees C from the produced water of ARCO'S Kuparuk oil field at Alaska and the subsurface water at the Lawrence Livermore National Laboratory gasoline-spill site, respectively. Both consortia were found to grow at 45-75 degrees C on BTEX compounds as their sole carbon and energy sources with 50 degrees C being the optimal temperature. With 3.5 mg total BTEX added to sealed 50-ml serum bottles, which contained 30 ml mineral salts medium and the consortium, benzene, toluene, ethylbenze, m-xylene, and an unresolved mixture of o- and p-xylenes were biodegraded by 22%, 38%, 42%, 40%, and 38%, respectively, by ALK-1 after 14 days of incubation at 50 degrees C. Somewhat lower, but significant, percentages of the BTEX compounds also were biodegraded at 60 degrees C and 70 degrees C. The extent of biodegradation of these BTEX compounds by LLNL-1 at each of these three temperatures was slightly less than that achieved by ALK-1. Use of [ring-14C]toluene in the BTEX mixture incubated at 50 degrees C verified that 41% and 31% of the biodegraded toluene was metabolized within 14 days to water-soluble products by ALK-1 and LLNL-1, respectively. A small fraction of it was mineralized to 14CO2. The use of [U-14C]benzene revealed that 2.6%-4.3% of the biodegraded benzene was metabolized at 50 degrees C to water-soluble products by the two consortia; however, no mineralization of the degraded [U-14C]benzene to 14CO2 was observed. The biodegradation of BTEX at all three temperatures by both consortia was tightly coupled to sulfate reduction as well as H2S generation. None was observed when sulfate was omitted from the serum bottles. This suggests that sulfate-reducing bacteria are most likely responsible for the observed thermophilic biodegradation of BTEX in both consortial cultures.

Coronary microvascular dysfunction is associated with ischemic-like electrocardiogram during exercise in patients with anginal chest pain and normal coronary angiograms

To determine the possible mechanism of the ischemic-like electrocardiogram (ECG) during exercise in the presence of anginal chest pain and normal coronary angiograms, both a treadmill exercise test (TET) and coronary hemodynamic study were prospectively performed in 33 consecutive patients (18 females and 15 males, aged 48 +/- 10 years) with angina of unknown cause. Although baseline characteristics and coronary hemodynamics were similar between patients with (TET+, n = 17) and those without (TET-, n = 16) ischemic-like ECG during TET, effort angina was more frequently seen in the former group (p < 0.01). Compared to TET- patients, TET+ patients had a significantly lower maximum great cardiac vein flow (GCVF, 108.8 +/- 47.0 vs 146.4 +/- 23.4 ml/min, p = 0.007), higher minimum coronary vascular resistance (0.94 +/- 0.41 vs 0.61 +/- 0.09 mmHg/ml/min., p = 0.003), and lower corrected GCVF (GCVF/rate-pressure product, 0.0087 +/- 0.0036 vs 0.0125 +/- 0.0019, p = 0.001) after dipyridamole infusion (0.56 mg/kg for 4 min). Though coronary flow reserve was significantly lower in TET+ than in TET- patients (2.26 +/- 0.59 vs 3.08 +/- 0.48, p = 0.0001), myocardial oxygen consumption and myocardial efficiency (rate-pressure product/myocardial oxygen consumption) were still similar between these two groups after dipyridamole infusion. Thus, coronary microvascular dysfunction rather than altered cardiac metabolism could contribute to effort angina and ischemic-like ECG during exercise in patients with anginal chest pain and normal coronary angiograms.

Peroxisomal activation of long- and very long-chain fatty acids in the yeast Pichia pastoris

In mammals, beta-oxidation of very long-chain fatty acids (VLCFA) takes place in peroxisomes. This process is impaired in X-linked adrenoleukodystrophy (XALD) patients as a result of decreased activity of peroxisomal very long-chain acyl-CoA synthetase (VLCS). We investigated VLCFA and long chain fatty acid (LCFA) activation in the yeast Pichia pastoris. Both VLCFA and LCFA were activated to their CoA derivatives in an organelle fraction. When organelles were fractionated on a sucrose gradient, VLCS activity co-localized with peroxisomes while long chain acyl-CoA synthetase activity associated primarily with mitochondria. Consistent with these findings, only VLCS activity was reduced in organelle fractions from peroxisome assembly (pas) mutants. Furthermore, no VLCS activity was detected in pas mutants at the density of normal peroxisomes. Thus, we conclude that VLCS is a peroxisomal enzyme in P. pastoris and this organism may serve as an excellent model system to investigate the molecular basis of XALD.

Comparison of respiratory activity and culturability during monochloramine disinfection of binary population biofilms

Biofilm bacteria challenged with monochloramine retained significant respiratory activity, even though they could not be cultured on agar plates. Microbial colony counts on agar media declined by approximately 99.9% after 1 h of disinfection, whereas the number of bacteria stained by a fluorescent redox dye experienced a 93% reduction. Integrated measures of biofilm respiratory activity, including net oxygen and glucose utilization rates, showed only a 10 to 15% reduction. In this biofilm system, measures of microbial respiratory activity and culturability yielded widely differing estimates of biocide efficacy.

Cytoplasmic CD3+ surface CD8+ lymphocytes develop as a thymus-independent lineage in chick-quail chimeras

We have analyzed the embryonic development of a population of lymphoid cells that express a CD3 antigenic determinant in the cytoplasm but not on the cell surface. Since these cells lack T cell receptor (TcR) molecules, we have provisionally named them TCRO cells. Their development, expansion and distribution was investigated following transplantation of splenic and bursal fragments from chicken embryos into quail embryos. Since quail cells are not recognized by our panel of monoclonal antibodies against chicken TcR1, TcR2, TcR3, CD3, CD4 and CD8 molecules, these antibodies provided reliable markers for donor chick lymphocytes in the tissues of the quail recipients. Transplanted spleen and bursa both generated CD3+ cells, the number of which increased as a function of age. Notably, approximately half of these CD3+ cells expressed surface CD8, but none acquired TcR1 (gamma/delta), TcR2 (alpha/beta) or TcR3 expression. Since TCRO cells normally appear first in the spleen of 8-day chick embryos (E8), their generation in E6 splenic transplants indicated an extrathymic origin. The TCRO cells of chick splenic origin migrated to the spleen, bursa and thymus of the quail recipients. In six of seven chimeras acquiring CT3+ cells in the recipient thymus, these cells were restricted to the medulla and displayed the typical TCRO phenotype: CD3+CD8+TcR1-TcR2-TcR3-. These intrathymic TCRO cells also lacked the CT1 thymocyte antigen. We conclude that the TCRO cells represent a thymus-independent lineage of lymphoid cells that can migrate into a receptive thymus by rarely, if ever, differentiate into conventional T cells.

Prevalence and significance of group B Streptococcus in a large obstetric population

Between Jan. 1 and Dec. 31, 1985, vaginal swabs were obtained for culture for group B beta-hemolytic Streptococcus (GBS) from 3078 women admitted for labour and delivery to Regina General Hospital. Seventy-one women had positive results; thus, the colonization rate was only 2.3%. The charts of the 71 women and their 73 babies were analysed. Of the 58 babies from whom swabs were obtained, 20 had GBS at one or more sites; the transmission rate was therefore 34%. Early-onset GBS disease developed in one infant. Two infants died within the first month; however, death was not directly attributable to GBS. Higher rates of preterm delivery and of low birth weight were noted among the babies of the colonized women than among the babies of all women admitted for labour and delivery in 1985. Given the low rate of GBS disease in our centre, we suggest that emphasis be placed on GBS as a possible source of obstetric complications such as preterm labour.