Infectious disease associations in advanced stage, indolent lymphoma (follicular and nonfollicular): developing a lymphoma prevention strategy

BACKGROUND

Eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tumor can result in lymphoma remission. We prospectively identified/treated infections in nonbulky, advanced stage indolent lymphoma (follicular; nonfollicular lymphoma) eligible for observation.

MATERIALS AND METHODS

Stool H. pylori, hepatitis C and Borrelia serologies, Borrelia and Chlamydia fixed tissue PCR, Chlamydia peripheral blood mononuclear cell PCR and hydrogen breath test for small bowel bacterial overgrowth (SBBO) were obtained.

RESULTS

Fifty-six patients were enrolled. Positive infections: H. pylori (13); hepatitis C (3); SBBO (11). Negative: Borrelia (13); Chlamydophila psittaci (12, except one PCR). Lymphoma responses to antimicrobial therapy: H. pylori [one complete response (CR), 24+ months; one transient near CR]; hepatitis C [two CRs, 18+ and 30+ months; one partial response (PR) but hepatitis C virus persistent]; SBBO (one PR, 30+ months). Patients with associated infections, but without lymphoma CR, have required lymphoma treatment sooner than those without initial infections (treatment-free survival at 23.4 months median follow-up, 40.5% versus 74.7%, P = 0.01), indicating a different biology.

CONCLUSION

Infections are common in advanced stage indolent lymphoma (37.5% in our series). Anecdotal lymphoma responses have been seen and three have been durable CRs (18 to 30+ months) with infection eradication alone. The identification and treatment of associated infections may be a first step towards developing a lymphoma prevention strategy.

Organizational manipulation of gonadal hormones and systemic morphine analgesia in female rats: effects of adult ovariectomy and estradiol replacement

Previous research has indicated the importance of sex in mediating the larger magnitude of mu-opioid receptor agonist-induced analgesia in male relative to female rodents. Whereas manipulations involving the adult activational effects of gonadal hormones minimally alter these analgesic sex differences, manipulations involving neonatal organizational effects of gonadal hormones have previously been shown to profoundly affect morphine analgesia. Thus, adult male rats neonatally castrated on the first day after birth displayed reductions in morphine analgesia relative to sham-operated males, and adult female rats neonatally treated with testosterone propionate on the first day after birth displayed enhancements in morphine analgesia relative to vehicle-treated females. Because neonatal androgenization in female rats produces an anovulatory syndrome that could change their adult hormonal milieu, the present study examined whether adult ovariectomy altered the magnitude of systemic morphine analgesia (1-5 mg/kg) in neonatal androgenized female rats relative to neonatal vehicle-treated female rats as well as gonadal steroid hormone replacement with estradiol benzoate. Intact male rats displayed significantly greater magnitudes and potencies (2- to 2.3-fold leftward shift) of systemic morphine analgesia than female rats treated neonatally with either vehicle (1-5 mg/kg) or testosterone (1.7-5 mg/kg). In turn, neonatal androgenized female rats displayed significantly greater magnitudes of systemic morphine (1, 5 mg/kg) analgesia than vehicle-treated female rats accompanied by a smaller 20% leftward shift in potency. Adult ovariectomy minimally affected morphine analgesia in neonatal vehicle-treated females, while significantly reducing the magnitude (1 mg/kg), but not the potency of morphine analgesia in neonatal androgenized female rats. Estradiol replacement therapy significantly increased the magnitude of morphine analgesia in both groups at some doses, but only changed the potency (20-30%) in females treated neonatally with vehicle. Taken together, these data suggest a limited organizational-activational gonadal hormone interaction in the mediation of systemic morphine analgesia in female rats.

The founder mutation MSH2*1906G-->C is an important cause of hereditary nonpolyposis colorectal cancer in the Ashkenazi Jewish population

Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by mutations in the mismatch-repair genes. We report here the identification and characterization of a founder mutation in MSH2 in the Ashkenazi Jewish population. We identified a nucleotide substitution, MSH2*1906G-->C, which results in a substitution of proline for alanine at codon 636 in the MSH2 protein. This allele was identified in 15 unrelated Ashkenazi Jewish families with HNPCC, most of which meet the Amsterdam criteria. Genotype analysis of 18 polymorphic loci within and flanking MSH2 suggested a single origin for the mutation. All colorectal cancers tested showed microsatellite instability and absence of MSH2 protein, by immunohistochemical analysis. In an analysis of a population-based incident series of 686 Ashkenazi Jews from Israel who have colorectal cancer, we identified 3 (0.44%) mutation carriers. Persons with a family history of colorectal or endometrial cancer were more likely to carry the mutation than were those without such a family history (P=.042), and those with colorectal cancer who carried the mutation were, on average, younger than affected individuals who did not carry it (P=.033). The mutation was not detected in either 566 unaffected Ashkenazi Jews from Israel or 1,022 control individuals from New York. In hospital-based series, the 1906C allele was identified in 5/463 Ashkenazi Jews with colorectal cancer, in 2/197 with endometrial cancer, and in 0/83 with ovarian cancer. When families identified by family history and in case series are included, 25 apparently unrelated Ashkenazi Jewish families have been found to harbor this mutation. Although this pathogenic mutation is not frequent in the Ashkenazi Jewish population (accounting for 2%-3% of colorectal cancer in those whose age at diagnosis is <60 years), it is highly penetrant and accounts for approximately one-third of HNPCC in Ashkenazi Jewish families that fulfill the Amsterdam criteria.

Utility of the full root bioprosthesis in surgery for complex aortic valve-ascending aortic disease

The objective of this study was to demonstrate the use of the full root bioprosthesis (Medtronic Freestyle) in the patient with complex aortic valve-ascending disease. Of 148 patients undergoing stentless aortic valve replacement since 4/98, 22 required concomitant replacement of the entire ascending aorta with a Dacron graft (beveled to include hemi-arch) for either "porcelain" aorta (8) or diffuse aneurysmal dilatation (14): 17/22 had aortic stenosis, 4/22 had aortic insufficiency, and 1 had bioprosthetic degeneration. All patients had right axillary cannulation, circulatory arrest at 18 C, and retrocerebral perfusion through the superior vena cava. Valve sizes included 23 mm (7), 25 mm (2), and 27 mm (13). Average age was 69.5 years, average intensive care unit stay was 64 hours, and average postoperative length of stay was 6.5 days. Although the initial intent was full root replacement, 7 patients had calcified coronary ostia precluding reimplantation. Subcoronary implantation techniques were modified to interdigitate the outflow suture lines between and through islands of calcium buttressed with small pericardial pledgets on the outside of the native aorta. All valves demonstrated either no or trace aortic regurgitation on pre-discharge transesophageal echocardiography, 30-day mortality was 0, and there were no neurologic sequelae. The full root bioprosthesis has great utility in surgery for complex aortic valve-ascending aortic disease. Axillary artery cannulation and retrograde cerebral perfusion provide a reproducible neurologically safe approach in this group of patients at high risk for intraoperative neurologic morbidity.

High incidence of severe twin hemodialysis catheter infections in elderly women. Possible roles of insufficient nutrition and social support

BACKGROUND

Cuffed-tunneled hemodialysis (HD) catheters are recommended as a bridging therapy until peripheral access is available, but their long-term use is controversial.

AIM

To evaluate the complications and lifetime of twin-tunneled HD catheters and to identify parameters which could predict their outcome.

METHODS

29 chronic HD patients (19 female and 10 male) were inserted with twin hemodialysis catheters (28 Tesio, 1 Schon Duoflow), followed for up to 9 months or until catheter loss, and evaluated for severe catheter-related complications necessitating catheter removal. Since the most common severe complication was catheter-related infection, we retrospectively examined whether parameters such as age, gender, duration of end-stage renal disease, delivered dose of dialysis, nutrition, diabetes and indices of social support correlate with this outcome.

RESULTS

Severe catheter infection requiring catheter removal occurred in 11 patients (10 female). Of these infected female patients, 9 were elderly (> or =67 years) and in 6 of those, catheter infection was fatal (54% of infected cases). At 9 months, severe catheter infection and related patient death rates were 38 and 21%, respectively. Severe catheter infection was significantly related to less social support (p < 0.005), older age, female gender, lower nPCR (all p < 0.05), and tended to be related to shorter end-stage renal disease duration prior to catheter insertion (p = 0.06).

CONCLUSION

This study demonstrated that twin HD catheters are associated with a high incidence of severe catheter-related infections which was most significantly related to social-support as well as inadequate nutrition, older age and female gender. Therefore, we suggest early removal of the catheter, enhancement of social support and dietary counseling for the elderly and lonely HD patients using this type of catheter.

Conformational modulation of human cytochrome P450 2E1 by ethanol and other substrates: a CO flash photolysis study

The alcohol-inducible cytochrome P450 2E1 is a major human hepatic P450 which metabolizes a broad array of endogenous and exogenous compounds, including ethanol, low-molecular weight toxins, and fatty acids. Several substrates are known to stabilize this P450 and inhibit its cellular degradation. Furthermore, ethanol is a known modulator of P450 2E1 substrate metabolism. We examined the CO binding kinetics of P450 2E1 after laser flash photolysis of the heme-CO bond, to probe the effects of ethanol and other substrates on protein conformation and dynamics. Ethanol had an effect on the two kinetic parameters that describe CO binding: it decreased the rate of CO binding, suggesting a decrease in the protein's conformational flexibility, and increased the photosensitivity, which indicates a local effect in the active site region such as strengthening of the heme-CO bond. Other substrates decreased the CO binding rate to varying degrees. Of particular interest is the effect of arachidonic acid, which abolished photodissociation in the absence of ethanol but had no effect in the presence of ethanol. These results are consistent with a model of P450 2E1 whereby arachidonic acid binds along a long hydrophobic binding pocket and blocks exit of CO from the heme region.

Effectiveness of erythropoiesis on supervised intradialytic oral iron and vitamin C therapy is correlated with Kt/V and patient weight

BACKGROUND

Poor compliance to oral medication and diet is common in hemodialysis (HD) patients and limits the ability of oral iron therapy to support erythropoiesis. Intravenous (i.v.) iron may be associated with undesirable and sometimes life-threatening complications.

PATIENTS AND METHODS

We hypothesized that intradialytic oral iron therapy can overcome compliance problems and support effective maintenance erythropoiesis, which will keep Hct in the range of 33% to 36% and EPO requirements up to 50 units/week/kg. In a prospective observational study, SC EPO-treated hospital-based HD patients without conditions known to cause EPO resistance, were managed on intradialytic oral administration of iron and vitamin C. The primary endpoints were EPO requirements and resistance to EPO which standardized EPO requirements by the Hct level. Secondary endpoints included parameters that might affect the primary endpoints. Exclusion criteria were refusal to take oral medication, prestudy Hct < 27%, recent i.v. iron therapy or transfusions, bleeding, clinical conditions obligating Hct > 30% and known causes of EPO resistance. Twelve patients completed minimal follow-up period of 9 months.

RESULTS

Mean Hct was 34.4% (range: 31.8% - 40.2%). EPO requirements were 61.7 +/- 28.2 units/kg and below 52.5 units/kg in 50% of patients. Patients were classified into equal groups according to resistance to EPO, which was positively correlated (r = 0.71 p < 0.01) with body weight and Kt/V (r = -0.38, p < 0.05).

CONCLUSION

In conclusion, intradialytic oral iron therapy can support effective maintenance erythropoiesis in 50% of patients without known causes for EPO resistance. High response to EPO and low EPO requirement are correlated with lower body weight and possibly improved dialysis.

Cutaneous ulcers associated with hydroxyurea therapy in myeloproliferative disorders

Hydroxyurea (HU) is an established chemotherapeutic agent in the treatment of myeloproliferative disorders (MPD) including chronic myelogenous leukemia (CML), polycythemia vera and essential thrombocythemia (ET). It is well tolerated, has minimal toxicities, and produces hematological response in most patients treated. Side effects of hydroxyurea are few and include myelosuppression, oral ulcers and skin rashes. Cutaneous toxicity is rare. This study aims to describe the occurrence of cutaneous ulcerations attributed to HU therapy in patients with MPD, and familiarize the oncology community with this unusual but disturbing toxicity of HU. Five patients with MPD receiving HU therapy at doses of 0.5 to 4 g/day who developed skin ulceration were reviewed (median age was 53 years). Three patients had Philadelphia positive CML, and two had ET. Cutaneous ulcers developed after a long period of HU therapy (median 36 months, range 7 to 96 months). The time after discontinuation of HU to the healing of the ulcers was 1 to 4 months. Ulcers developed mainly in the lower extremities particularly adjacent to the malleoli, indicating a possible relation to trauma. In conclusion, cutaneous ulceration represents a poorly recognized and rare HU-related side effect. Discontinuation of HU usually leads to slow resolution of the ulcers over several months. The etiology of this rare side effect remains poorly understood.

Ondansetron with propofol reduces the incidence of emesis in children following tonsillectomy

PURPOSE

This study tested the hypothesis that the antiemetic effects of a combination of ondansetron and propofol were superior to propofol alone in children undergoing tonsillectomy surgery.

METHODS

A prospective, randomized, double-blind, placebo-controlled study design was employed. Young children underwent mask induction with halothane, nitrous oxide and oxygen and then had i.v. access established: older children had i.v. induction with propofol. All patients received 0.3 mg x kg(-1) mivacurium and 2-4 microg x kg(-1) fentanyl i.v. and 30 mg x kg(-1) acetaminophen pr to a maximum dose of 650 mg. Following induction, patients received either 100 microg x kg(-1) ondansetron or placebo. Anaesthesia was maintained with 120-140 microg x kg(-1) x min(-1) propofol, nitrous oxide and oxygen to maintain vital signs within 20% of baseline. After surgery, in all patients the tracheas were extubated in the operating room without use of neuromuscular reversing agents. Episodes of emesis were recorded by PACU nurses for four to six hours. A telephone interview on the following day was also used for data recovery. Groups were compared in relation to age using the Mann-Whitney test, and with respect to sex and number of episodes of vomiting using the Fisher Exact Test.

RESULTS

Three of the 45 patients who received ondansetron vomited (6.7%), whereas 10 of the 45 patients who received placebo vomited (22.2%). (P = 0.035)

CONCLUSION

Ondansetron in a dose of 100 microg x kg(-1), when combined with propofol for children undergoing tonsillectomy reduced the incidence of postoperative vomiting to very low levels.

Familial colorectal cancer in Ashkenazim due to a hypermutable tract in APC

Approximately 130,000 cases of colorectal cancer (CRC) are diagnosed in the United States each year, and about 15% of these have a hereditary component. Two well-defined syndromes, familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), account for up to 5% of the total new cases of CRC. Truncating APC mutations are responsible for FAP, and defective mismatch repair genes cause HNPCC. However, the genes responsible for most of the familial cases are unknown. Here we report a mutation (T to A at APC nucleotide 3920) found in 6% of Ashkenazi Jews and about 28% of Ashkenazim with a family history of CRC. Rather than altering the function of the encoded protein, this mutation creates a small hypermutable region of the gene, indirectly causing cancer predisposition.

Differential interaction of erythromycin with cytochromes P450 3A1/2 in the endoplasmic reticulum: a CO flash photolysis study

The kinetics of CO binding to cytochromes P450, measured by the flash photolysis technique, were used to probe the interaction of erythromycin with cytochromes P450 in rat liver microsomes. Addition of erythromycin generates substrate difference spectra using microsomes from rats treated with phenobarbital or dexamethasone but not from untreated rats, showing that it binds to P450s induced by these agents. In contrast, erythromycin and/or a monoclonal antibody to P450 3A1/2 accelerated CO binding to microsomes from rats treated with phenobarbital but had no effect on microsomes from untreated or dexamethasone-treated rats. Based on the differential amounts and inducibilities of the P450 3A1 and 3A2 forms in these microsomal samples, these results indicate that erythromycin increased the rate for P450 3A2 but not P450 3A1. The divergent effects of erythromycin on these P450s, which exhibit 89% sequence similarity, were consistent with a model of the P450 substrate binding site in which erythromycin forms a more rigid complex with P450 3A1 than P450 3A2. These results demonstrate the sensitivity of P450 conformation/dynamics to substrate binding, and show that CO binding kinetics can distinguish among closely related P450s in a microsomal environment.

Drug-drug interactions: effect of quinidine on nifedipine binding to human cytochrome P450 3A4

Quinidine is a known inhibitor of cytochrome P450-mediated nifedipine metabolism. The interactions of nifedipine and quinidine with human cytochrome P450 3A4, which metabolizes these drugs, were examined using the kinetics of CO binding to this P450 as a rapid kinetic probe of protein conformation and dynamics. This approach showed that nifedipine and quinidine bind to different P450 3A4 species, respectively termed species I and II, with distinct conformations. When both drugs were present simultaneously, nifedipine interacted with the quinidine-bound P450 species II, but not species I. These findings indicate that quinidine acts as an allosteric inhibitor by switching nifedipine binding from nifedipine-metabolizing species I to the nonmetabolizing species II.

Differential mechanisms of cytochrome P450 inhibition and activation by alpha-naphthoflavone

The anticarcinogenicity of some flavonoids has been attributed to modulation of the cytochrome P450 enzymes, which metabolize procarcinogens to their activated forms. However, the mechanism by which flavonoids inhibit some P450-mediated activities while activating others is a longstanding, intriguing question. We employed flash photolysis to measure carbon monoxide binding to P450 as a rapid kinetic technique to probe the interaction of the prototype flavonoid alpha-naphthoflavone with human cytochrome P450s 1A1 and 3A4, whose benzo[a]pyrene hydroxylation activities are respectively inhibited and stimulated by this compound. This flavonoid inhibited P450 1A1 binding to benzo[a]pyrene via a classical competitive mechanism. In contrast, alpha-naphthoflavone stimulated P450 3A4 by selectively binding and activating an otherwise inactive subpopulation of this P450 and promoting benzo[a]pyrene binding to the latter. These data indicate that flavonoids enhance activity by increasing the pool of active P450 molecules within this P450 macrosystem. Activators in other biological systems may similarly exert their effect by expanding the population of active receptor molecules.

Interaction of polycyclic aromatic hydrocarbons with human cytochrome P450 1A1: a CO flash photolysis study

The kinetics of CO binding to human cytochrome P450 1A1 was used to probe the interaction of polycyclic aromatic hydrocarbons (PAHs) with the membrane-bound P450 expressed in baculovirus-infected SF9 insect cells. Biexponential kinetics was observed, indicating that P450 1A1 is composed of at least two kinetically distinguishable species. To define the substrate specificity of the individual species, we evaluated the effect of a series of PAHs of varying sizes and shapes on the CO binding kinetics of P450 1A1. The overall rate of CO binding was increased in the presence of the tricyclic PAHs phenanthrene and anthracene and the tetracyclic PAHs pyrene and 1,2-benzanthracene, but was decreased by the pentacyclic PAHs benzo[a]pyrene and 1,2:3,4-dibenzanthracene. A kinetic difference method was applied to kinetically define the individual P450 1A1 species. Two species differing in their PAH specificities were identified: a slowly reacting species sensitive to the smaller PAHs, and a rapidly reacting species responsive to larger PAHs. Upon PAH binding, CO binding to these species was accelerated and decelerated, respectively. The results furthermore suggest that the two species are interconvertable. In addition to PAHs, the interactions of P450 1A1 with 7-ethoxy- and 7-pentoxyresorufin were likewise examined for their effect on the CO binding kinetics. These compounds interacted with and decreased the rate of the rapidly and slowly reacting P450 1A1 species, respectively. The markedly variable effects of these PAHs and resorufins on the CO binding kinetics indicate differential modes of interaction with the two target P450 1A1 species, resulting in differential modulation of their conformations. These results demonstrate that multiple P450 1A1 species with distinct conformations and substrate recognition profiles coexist in a biological membrane and are resolvable using a rapid kinetic technique.

Phase II trial of intravenous flourouracil and subcutaneous interferon alfa-2b for biliary tract cancer

PURPOSE

To assess the efficacy of systemic intravenous-fluorouracil (5-FU) and subcutaneous recombinant human interferon alfa-2b (rIFN alpha-2b) in patients with measurable cancer of the biliary tree.

PATIENTS AND METHODS

Thirty-five patients (25 with cholangiocarcinoma and 10 with gallbladder carcinoma) were registered onto this phase II protocol between 1992 and 1995. Patients received a continuous infusion of 750 mg/m2/d of 5-FU on days 1 through 5 through a centrally placed venous catheter and a subcutaneous injection of 5 MU/m2 of rIFN alpha-2b on days 1, 3, and 5. Treatment cycles were repeated every 14 days; one course of therapy included four treatment cycles. Disease status was assessed every 8 weeks. Dosages were lowered for grade III mucositis. Fourteen patients had prior treatment and, before initiating this therapy, 17 patients required decompression of the biliary tree.

RESULTS

Eleven of 32 (34%) assessable patients had a partial response. The median time to disease progression was 9.5 months, and the median survival time 12 months. Grade III to IV toxic effects were granulocytopenia (14%), mucositis (20%), diarrhea (9%), and dermatitis (11%). Grade III to IV asthenia and fatigue were observed in 6% of patients.

CONCLUSION

Drug tolerance was better among previously untreated patients. To achieve a complete response, additional chemotherapy or radiotherapy should be considered when liver resection or transplantation is not feasible. However, if these results can be reproduced by other investigators, the regimen should be studied for adjuvant treatment of gallbladder carcinoma incidentally identified in patients undergoing cholecystectomy.

Phase II study of paclitaxel therapy for unresectable biliary tree carcinomas

PURPOSE

To evaluate the efficacy of paclitaxel administered to patients with unresectable adenocarcinomas of the gallbladder and biliary tree over 3 hours every 21 days.

PATIENTS AND METHODS

Fifteen patients with unresectable and/or metastatic carcinoma of the gallbladder and bile ducts received intravenous paclitaxel over 3 hours after premedication with dexamethasone, diphenhydramine, and cimetidine. Treatment was repeated every 21 days, and one complete course of therapy was comprised of two such 21-day treatment cycles. The initial dose of paclitaxel was 170 mg/m2, and this was elevated to 200 mg/m2 due to tolerance within the initial patient cohort.

RESULTS

All patients were assessable for both toxicity and response: 11 with bile duct cancer and four with gall-bladder carcinoma. Forty-three cycles of therapy were delivered during the trial (median, two), and one patient remains on treatment. No complete or partial responses were noted, although two patients achieved minor responses that lasted 2 and 2+ months, respectively. There were no deaths on this study, and all but one of the patients is still alive. The therapy was well tolerated, and hematologic and mucosal toxic effects were moderate and readily reversible, although significant neuromuscular adverse effects were noted.

CONCLUSION

These findings indicate that paclitaxel, administered on this schedule, is tolerable, but is unlikely to have activity in metastatic carcinomas of the biliary tree. It is unclear whether a different regimen of paclitaxel, or another taxane, may have activity in these neoplasms.

Preliminary results for positron emission mammography: real-time functional breast imaging in a conventional mammography gantry

In order to optimally integrate radiotracer breast imaging within the breast clinic, anatomy and pathology should be easily correlated with functional nuclear medicine breast images. As a first step in the development of a hybrid functional/anatomic breast imaging platform with biopsy capability, a conventional X-ray mammography gantry was modified to image the compressed breast with positron emitters. Phantom studies with the positron emission mammography (PEM) device showed that a 1-cc hot spot could be detected within 5 min. A preliminary clinical trial demonstrated in vivo visualization of primary breast cancer within 4 min. For sites where positron-emitting radionuclides are available, PEM promises to achieve low-cost directed functional examination of breast abnormalities, with the potential for achieving X-ray correlation and image-guided biopsy.