Neutrophils from patients after burn injury express a deficiency of the oxidase components p47-phox and p67-phox

Infection is a major cause of morbidity and mortality in patients after thermal injury. This predisposition to infections is related, in part, to abnormal polymorphonuclear leukocyte (PMN) function and a diminished respiratory burst. To evaluate the biochemical basis for the defective respiratory burst after major burns, the status of the oxidase enzyme system and its components was investigated. PMNs were isolated from 24 patients with 12% to 62% burns. Oxidase activity of intact PMNs, measured as superoxide anion (O2-) generation or oxygen consumption, was decreased in burn compared with healthy controls. Subcellular fractions from patient PMNs generated less O2- in the sodium dodecyl sulfate cell-free system, and this was related to a diminished contribution by cytosol but not by plasma membrane. Subsequently, cytosol was separated with CM-Sepharose, yielding two fractions; one contained the p47-phox and p67-phox (47/67 mix) and the other contained the remaining cytosolic components (run through [RT]). Although the contribution to oxidase activity made by RT from patient cytosol was similar to that of control, the activity of p47/67 mix from PMNs of burn patients was deficient. Quantitative assays using an immunoautoradiographic technique showed a consistent, but significant decrease in both p47-phox and p67-phox. The addition of purified or human recombinant p47-phox but not p67-phox corrected the diminished oxidase activity of cytosol from burn patients. Thus, decreased respiratory burst activity found in PMNs from individuals with thermal injury was associated with a specific, quantitative deficiency of p47-phox.

[Detection of nicotine in prehistorical skeletal remains of South China]

Human remains from excavation sites in southern China, dated from 100 to 10,000 years, were investigated for nicotine. The nicotine concentrations were measured by radioimmunoassay. Consequently, the values measured represent the sum of nicotine and its metabolites. Positive results were observed in 25.9% (mean values of all samples). The concentrations ranged from 11.8 to 474.2 ng/g sample. From the excavation sites with the highest number of individuals, Chongtong (18 individuals) were 38.9%, and from the site Leigund (21 individuals) were 28.6% from the samples nicotine positive. The highest level with 474.2 ng/g nicotine was found in a sample dated 100 years. It is possible, that this individual was smoker. In addition the samples were investigated also by gas chromatography/mass spectrometry. The GC/MS indicated the presence of nicotine and its primary metabolite, cotinine. The presence of cotinine points out the assumption that nicotine was used antemortem. The detection of unchanged nicotine indicates that nicotine remained present in bones up centuries.

Analysis of adverse effects among patients with essential hypertension receiving an ACE inhibitor or a beta-blocker

Evaluation of safety and efficacy of new drugs is based largely on data from clinical trials involving a limited number of patients. This approach does not necessarily detect the rare adverse events that may only be observed when very large numbers of patients are studied. Consequently, we designed a double-blind 12-week trial comparing the new angiotensin-converting enzyme (ACE) inhibitor, quinapril (n = 5,053), with a well-established beta-adrenergic receptor blocker, metoprolol (n = 506). Essentially hypertensive patients (diastolic blood pressure 95-114 mm Hg) received either 10 mg quinapril or 50 mg metoprolol once daily, and the doses were doubled at 4-week intervals to a maximum of 40 and 200 mg, respectively, in nonresponders. Responder rates were similar under both regimens. Adverse events were assessed by interview as well as by a standard questionnaire. The overall prevalence of adverse events reported by standard questionnaire was higher than that reported spontaneously during interviews. With respect to typical ACE inhibitor adverse reactions (e.g. cough and taste disturbances), there was no difference between quinapril and metoprolol independent of the mode of reporting. In summary, both drugs showed comparable overall tolerance and safety. The discrepancy between spontaneously reported and questionnaire-reported adverse events was noteworthy, and this finding prevailed in a volunteer group of 327 patients who were treated with quinapril for 52 weeks. Thus, a questionnaire is of great significance in addition to the patient history/interview in a large-scale, double-blind study designed to learn about details of drug safety.

Double-blind, randomized study of primary hormonal treatment of stage D2 prostate carcinoma: flutamide versus diethylstilbestrol

PURPOSE

Patients with stage D2 prostate carcinoma are often treated initially with hormones to decrease endogenous testosterone. Therapy with diethylstilbestrol (DES), leuprolide, or bilateral orchiectomy has been reported to be equivalent. DES is the cheapest preparation, but has the potential for serious cardiovascular or thromboembolic complications. Flutamide is a novel antiandrogen with fewer side effects.

PATIENTS AND METHODS

The Eastern Cooperative Oncology Group (ECOG) conducted a double-blind, randomized study to compare the efficacy of flutamide (250 mg three times daily) to DES (1 mg three times daily) as the primary hormonal therapy for patients with stage D2 prostate cancer. Patients were stratified by performance status, disease sites, and history of cardiovascular disease at randomization.

RESULTS

Forty-eight patients received DES and 44 flutamide. Patient characteristics were evenly distributed between the two treatments. The overall response rate was similar (DES, 62%; flutamide, 50%). Grade III or worse cardiovascular or thromboembolic toxicity developed in 33.3% of patients on DES and in 17.6% on flutamide (P = .051). Other toxicities were similar between the two treatment arms. However, DES produced significantly longer time to treatment failure (26.4 v 9.7 months, P = .016) and longer survival than flutamide (43.2 v 28.5 months, P = .040).

CONCLUSION

As the primary hormonal therapy for stage D2 prostate cancer, DES caused more serious cardiovascular or thromboembolic complications than flutamide. Despite this, flutamide was not as active an initial agent as DES. However, the effectiveness of flutamide in conjunction with other agents compared with DES remains undetermined, and the optimal initial hormone therapy of stage D2 prostate cancer requires further studies.

Rescue of HSV-1 neurovirulence is associated with induction of brain interleukin-1 expression, prostaglandin synthesis and neuroendocrine responses

Several HSV-1 neurovirulence genes have been mapped but the mechanisms by which they affect host-virus interactions are not known. We have previously mapped HSV-1 neurovirulence to the UL53 gene region of the viral DNA by transfer of this gene from the neurovirulent R-19 strain to the non-neurovirulent R-15 strain in the generation of the p-71 recombinant, in which neurovirulence was rescued. In the present study we inoculated these strains into the paraventricular nucleus (PVN) of the hypothalamus of rats. We examined: (1) Clinical course of encephalitis. (2) Hypothalamic-pituitary-adrenocortical (HPA) axis function. (3) Brain cytokine gene mRNA expression and prostaglandin E2 (PGE2) production. (4) The relation of these parameters to viral replication and to cellular inflammation. In R-15 infected rats no signs of disease were observed. There was a temporary inflammatory reaction and IL-1 beta transcription in the PVN area. The function of the HPA axis was similar to control rats. Only slight increase in brain PGE2 production was found. In R-19 and p-71 infected rats, overt clinical signs of encephalitis and cellular inflammation in the PVN area were observed within 3 days post-infection (p.i). All rats died between 4-7 days p.i. These strains induced IL-1 beta transcription in the hypothalamus as well as in extra-hypothalamic brain regions in which no cellular inflammation was found. Basal serum ACTH and' CS were markedly elevated and hypothalamic CRF-41 content was significantly reduced as compared to R-15 infected rats. Both strains markedly increased brain PGE2 production. HSV-1 brain titers at 3 days p.i. were 100-fold lower than the inoculum titer although clinical signs of encephalitis were prominent. The results suggest that rescue of HSV-1 neurovirulence by the UL53 gene region of the viral genome is associated with enhancement of viral-induced brain IL-1 beta gene expression, increased brain PGE2 synthesis and hypersecretion of HPA axis hormones. Viral-induced brain derived cytokines and prostaglandins may contribute to the clinical syndrome of acute herpetic encephalitis in particular at early stages of the disease when virus load in the brain is low and cellular infiltrates are not widespread.

Successful transplantation of HLA-matched and HLA-mismatched umbilical cord blood from unrelated donors: analysis of engraftment and acute graft-versus-host disease

To reduce the morbidity and mortality associated with unrelated donor bone marrow (BM) transplantation and potentially extend the pool of suitable donors, cryopreserved unrelated donor umbilical cord blood was considered as an alternate source of hematopoietic stem cells for transplantation. Patients with leukemia, BM failure syndrome, or inborn error of metabolism were eligible for a phase I clinical trial designed to estimate the risk of graft failure and severe acute graft-versus-host disease after transplantation of umbilical cord blood from unrelated donors. As of December 21, 1995, unrelated donor umbilical cord blood was used to reconstitute hematopoiesis in eighteen patients aged 0.1 to 21.3 years weighing 3.3 to 78.8 kg with acquired or congenital lympho-hematopoietic disorders or metabolic disease. Patients received either HLA-matched (n = 7) or HLA-1 to 3 antigen disparate (n = 11) grafts collected and evaluated by the New York Blood Center (New York, NY). The probability of engraftment after unrelated donor umbilical cord blood transplantation was 100% with no patient having late graft failure to date. The probability of grade III-IV acute graft-versus-host disease at 100 days was 11%. With a median follow-up of 6 months (range, 1.6 to 17 months); the probability of survival at 6 months is 65% in this high risk patient population. We conclude that cryopreserved umbilical cord blood from HLA-matched and mismatched unrelated donors is a sufficient source of transplantable hematopoietic stem cells with high probability of donor derived engraftment and low risk of refractory severe acute graft-versus-host disease. Limitations with regard to recipient size and degree of donor HLA disparity remain to be determined.

Phase II trial of heparin prophylaxis for veno-occlusive disease of the liver in children undergoing bone marrow transplantation

Veno-occlusive disease (VOD) of the liver is an early complication of bone marrow transplantation (BMT). The initial event has been hypothesized to be an injury to the endothelial cells eventually resulting in post-sinusoidal obstruction and hepatic failure. The role of anticoagulants for the prevention of VOD is controversial. Continuous infusion of heparin has been reported to be effective in preventing VOD in adults undergoing myeloablative therapy and BMT. An unblinded, historical controlled study was carried out to assess the safety and efficacy of continuous infusion of low-dose heparin in prevention of VOD in children undergoing BMT following myeloablative therapy. Fifty consecutively BMT-treated children (10 months to 18 years 7 months) were enrolled into the study group and received continuous heparin infusion (100 units/kg/day) from the first day of the preparative regimen to day +30 or until discharge, whichever occurred earlier. These were compared with a control group of 70 patients who received BMT for a variety of disorders. Patient groups were similar with respect to primary diagnosis, age, sex, and baseline organ functions. Heparin was well-tolerated, with only minor grade I-II hemorrhagic episodes occurring in 28 patients (56%), compared to 50 patients in the control group (71%) (P = 0.184). Bleeding was significantly less following autologous BMT compared to allogeneic BMT (P < 0.05). VOD was diagnosed in five patients (10%) compared to 18 of 70 in the control group (25.7%) (P < 0.05). Analysis of risk factors demonstrated a significantly higher incidence of VOD in patients undergoing allogeneic BMT (matched related, mismatched related and matched unrelated), patients older than 15 years of age, and patients with advanced disease (> or = 2 CR). In summary, this phase II trial has demonstrated that continuous heparin infusion can be safely used prophylactically in children undergoing myeloablative therapy and BMT. The incidence of moderate and serious VOD was significantly less compared to historical controls. A future randomized, double-blinded, placebo-controlled phase III trial is, however, required to determine the efficacy of heparin in preventing VOD in children undergoing myeloablative therapy and BMT.

Follow-up assessment of medication-treated dysthymia

1. The objective was to assess long-term efficacy of antidepressant medications in dysthymia. 2. In a naturalistic study, patients with DSMIII-R dysthymia who had participated in previous antidepressant trials with fluoxetine and trazodone were evaluated at a mean of 40.0 weeks of follow-up to assess whether medication response persisted over time. A multivariate analysis was performed for patients on vs. off medication. Relapse rates (with relapse defined as HDRS score > 13) were also compared for these two groups. 3. Of 40 patients, the 24 still on medication showed significantly lower scores on most rating scales (HDRS, Cornell Dysthymia Rating Scale, and CGI, but not on the SCL-58) than the heterogeneous group of 16 patients not taking medication. Relapse was low (17.4%) among patients remaining on medication. 4. These preliminary findings suggest that dysthymia patients who remain on medication maintain improvement over time.

Adrenocortical activation by herpes virus: involvement of IL-1 beta and central noradrenergic system

We investigated the involvement of brain cytokines and central monoamines in mediating the effect of the neurotropic herpes simplex virus-1 (HSV-1) on adrenocortical activity in rats. Corneal inoculation with a neurovirulent HSV-1 strain, but not with an avirulent strain, induced interleukin-1 beta (IL-1 beta) gene expression mainly in the pons and hypothalamus, and caused an elevation in serum corticosterone levels. Infectious virus was isolated in low titres only from the trigeminal ganglia and pons. Viral DNA was detected by PCR in these tissues and in other brain regions. Virus-induced adrenocortical activation was abolished in rats in which hypothalamic norepinephrine (NE) was depleted by 6-hydroxydopamine. Depletion of hypothalamic serotonin by 5,7-dihydroxytryptamine did not prevent adrenocortical activation. These results suggest that central IL-1 and NE are involved in HSV-1 induced adrenocortical activation.

Effect of acidic phospholipids on sphingosine kinase

Sphingosine-1-phosphate (SPP) is a unique sphingolipid metabolite involved in cell growth regulation and signal transduction. SPP is formed from sphingosine in cells by the action of sphingosine kinase, an enzyme whose activity can be stimulated by growth factors. Little is known of the mechanisms by which sphingosine kinase is regulated. We found that acidic phospholipids, particularly phosphatidylserine, induced a dose-dependent increase in sphingosine kinase activity due to an increase in the apparent Vmax of the enzyme. Other acidic phospholipids, such as phosphatidylinositol, phosphatidic acid, phosphatidylinositol bisphosphate, and cardiolipin stimulated sphingosine kinase activity to a lesser extent than phosphatidylserine, whereas neutral phospholipids had no effect. Diacylglycerol, a structurally similar molecule which differs from phosphatidic acid in the absence of the phosphate group, failed to induce any changes in sphingosine kinase activity. Our results suggest that the presence of negative charges on the lipid molecules is important for the potentiation of sphingosine kinase activity, but the effect does not directly correlate with the number of negative charges. These results also support the notion that the polar group confers specificity in the stimulation of sphingosine kinase by acidic glycerophospholipids. The presence of a fatty acid chain in position 2 of the glycerol backbone was not critical since lysophosphatidylserine also stimulated sphingosine kinase, although it was somewhat less potent. Dioleoylphosphatidylserine was the most potent species, including a fourfold stimulation, whereas distearoyl phosphatidylserine was completely inactive. Thus, the degree of saturation of the fatty acid chain of the phospholipids may also play a role in the activation of sphingosine kinase.

Pranidipine, a novel calcium antagonist, once daily, for the treatment of hypertension: a multicenter, double-blind, placebo-controlled dose-finding study

The antihypertensive effects and tolerance of once-daily (od), pranidipine, a novel dihydropyridine derivative with a long duration of action, were evaluated in a double-blind, placebo-controlled, parallel-group dose-finding study. A total of 199 patients, with a diastolic blood pressure (BP) of 95-115 mmHg, were included in the trial. After 4 weeks on placebo, patients were randomly assigned to either placebo or pranidipine at 1, 2, 4, or 8 mg od for a further 4 weeks. A dose response was seen in the reduction (delta) of diastolic BP: placebo, delta 1.7 mm Hg; 1 mg, delta 6.4 mmHg; 2 mg, delta 7.5 mmHg, p < 0.01; 4 mg, delta 11.5 mmHg, p < 0.01; and 8 mg, delta 10.6 mmHg, p < 0.01. There were no meaningful changes in heart rate. The number of responders (decrease of diastolic blood pressure to < 90 mmHg and by 10 mmHg or more from baseline value) in each group also revealed a dose-response relationship: placebo = 9%; 1 mg = 25%, n.s.; 2 mg = 27%, n.s.; 4 mg = 41.5%, p < 0.01; and 8 mg = 41%, p < 0.01 (compared with placebo). Plasma concentrations of pranidipine also demonstrated linear dose-response relationships. An increase in adverse events was observed within the 8 mg group. The degree of reduction in BP and the number of responders were not greater in the 8 mg group compared with the 4 mg group, although the plasma concentration (mean values, ng/dl) of pranidine in the 8 mg group was higher (2.2 on day 42; 2.3 on day 56) compared with the 4 mg group (1.4 on day 42; 1.6 on day 56). In conclusion, pranidipine is a well-tolerated and 24-hour effective novel calcium antagonist that reduces BP in a dose-related manner up to 4 mg od.

A two-year follow-up of neonates with presumed sepsis treated with recombinant human granulocyte colony-stimulating factor during the first week of life

We have previously reported that recombinant human granulocyte colony-stimulating factor was well tolerated and resulted in sustained neutrophilia and improvement of neutrophil functions in newborn infants with presumed sepsis. We now report a 2-year follow-up on 21 of the initial cohort of 28 patients. Treatment with recombinant human granulocyte colony-stimulating factor in neonates with presumed sepsis was not associated with any long-term adverse hematologic, immunologic, or developmental effects.

Results of a phase I/II trial of recombinant human granulocyte-macrophage colony-stimulating factor in very low birthweight neonates: significant induction of circulatory neutrophils, monocytes, platelets, and bone marrow neutrophils

Neonates, especially those of very low birthweight (VLBW), have an increased risk of nosocomial infections secondary to deficiencies in development. We previously demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) production and mRNA expression from stimulated neonatal mononuclear cells are significantly less than that from adult cells. Recombinant murine GM-CSF administration to neonatal rats has resulted in neutrophilia, increased neutrophil production, and increased survival of pups during experimental Staphylococcus aureus sepsis. In the present study, we sought to determine the safety and biologic response of recombinant human (rhu) GM-CSF in VLBW neonates. Twenty VLBW neonates (500 to 1,500 g), aged < 72 hours, were randomized to receive either placebo (n = 5) or rhuGM-CSF at 5.0 micrograms/kg once per day (n = 5), 5.0 micrograms/kg twice per day (n = 5), or 10 micrograms/kg once per day (n = 5) given via 2-hour intravenous infusion for 7 days. Complete blood counts, differential, and platelet counts were obtained, and tibial bone marrow aspirate was performed on day 8. Neutrophil C3bi receptor expression was measured at 0 and 24 hours. GM-CSF levels were measured by a sandwich enzyme-linked immunosorbent assay at 2, 4, 6, 12, and 24 hours after the first dose of rhuGM-CSF. At all doses, rhuGM-CSF was well tolerated, and there was no evidence of grade III or IV toxicity. Within 48 hours of administration, there was a significant increase in the circulating absolute neutrophil count (ANC) at 5.0 micrograms/kg twice per day and 10.0 micrograms/kg once per day, which continued for at least 24 hours after discontinuation of rhuGM-CSF. When the ANC was normalized for each patient's first ANC, there was a significant increase in the ANC on days 6 and 7 at each dose level. By day 7, all tested doses of rhuGM-CSF resulted in an increase in the absolute monocyte count (AMC) compared with placebo-treated neonates. In those receiving rhuGM-CSF 5.0 micrograms/kg twice per day, there was additionally a significant increase in the day 7 and 8 platelet count. Tibial bone marrow aspirates demonstrated a significant increase in the bone marrow neutrophil storage pool (BM NSP) at 5.0 micrograms/kg twice per day and 10.0 micrograms/kg once per day. Neutrophil C3bi receptor expression was significantly increased 24 hours after the first dose of rhuGM-CSF at 5.0 micrograms/kg once per day. The elimination half-life (T1/2) of rhuGM-CSF was 1.4 +/- 0.8 to 3.9 +/- 2.8 hours.(ABSTRACT TRUNCATED AT 400 WORDS)

The role of cytokines in modulating neonatal myelopoiesis and host defense

Neonatal sepsis is a major cause of morbidity and mortality in newborn infants. Hematopoiesis and host defense in the neonate is developmentally immature compared with the adult. Defects in both the quantitative and qualitative aspects of the phagocytic system contribute significantly to a relative state of immunodeficiency in the neonate. Dysregulation of neonatal hematopoiesis and the immune response is a significant contributing factor to the increased susceptibility of the neonate to infection. A relatively small set of pluripotent stem cells gives rise to large numbers of functionally diverse mature effector cells. Cell proliferation and differentiation are regulated and controlled by highly specific protein factors, affecting single and multiple lineage hematopoiesis. Reduced neonatal rat myeloid progenitor pools, accelerated myeloid progenitor proliferative rates and decreased total body neutrophil storage pools predispose the newborn rat to depletion of mature effector neutrophils and a tendency to develop neutropenia during states of increased demand such as overwhelming bacterial infection. We review here the multifactorial complex biological process involved in the regulation of hematopoietic growth factors. We also review the biological effects of various non-lineage-committed and lineage-committed growth factors as reported in in vitro investigations and in vivo neonatal animal experiments. We also review our results of phase I/II clinical studies utilizing rhuG-CSF in neonates with presumed sepsis, and of rhuGM-CSF in very low birth weight neonates.

Comparison of the positional cloning methods used to isolate the BRCA1 gene

A critical step in positional cloning is the identification of candidate genes from a large, genetically defined region. Candidate gene isolation by hybrid selection, genomic sequencing, and direct cDNA library screening identified 45 candidate gene fragments (CGFs) from a 600 kb genomic region that contains the BRCA1 gene. These CGFs define a minimum of 15 genes, six of which are newly localized to the BRCA1 region. We present an analysis of the efficiency and the sequences generated for each of these methods. We also compare our CGF set to those reported for the BRCA1 region by three other groups, revealing a surprising lack of overlap among the sets.

The immunization of children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC). The impact of different strategies

OBJECTIVE

To assess the impact of different interventions to increase measles vaccination coverage among preschool children enrolled in the Special Supplemental Food Program for Women, Infants, and Children (WIC).

DESIGN

Public health intervention trial.

SETTING

Six volunteer WIC sites in New York City.

STUDY PARTICIPANTS

Children aged 12 to 59 months presenting for WIC certification between April 1 and September 30, 1991, who were eligible for measles vaccination.

INTERVENTIONS

Two WIC sites were assigned at random to one of three immunization strategies: (1) escort: child was escorted to a nearby pediatric clinic for immunization; (2) voucher incentive: the family returned monthly, rather than every 2 months, to pick up WIC food vouchers until the child was immunized; or (3) referral: the family was passively referred for immunization.

MAIN OUTCOME MEASURE

Proportion of eligible children receiving measles vaccination.

RESULTS

Of children eligible for measles immunization, 74% (618/836) were immunized. Children at escort sites were 5.5 times (relative risk [RR] = 5.5; 95% confidence interval [CI], 3.7 to 8.1) and those at voucher incentive sites were 2.9 times (RR = 2.9; 95% CI, 1.9 to 4.5) more likely to be immunized than children at referral sites. Children were immunized more rapidly at escort sites (median, 14 days) and voucher incentive sites (median, 26 days) than at referral sites (median, 45 days; P < .001).

CONCLUSIONS

Both escort and voucher incentive models resulted in more children being immunized more rapidly than passive referral. Because of ease of administration, voucher incentives may be a more suitable immunization intervention for use at WIC sites, with addition of escort where feasible.

Delivery systems for vision care benefits

The best way to provide a vision care benefit is with a managed care plan. With this type of design, there is cost containment without cost shifting, and quality assurance and member satisfaction are readily attainable at relatively inexpensive rates.

Effect of fiber and its fermentation on colonic adaptation after cecal resection in the rat

BACKGROUND

The role of fiber in postresection adaptation is poorly understood. We examined the significance of short-chain fatty acids produced by intracolonic fiber fermentation during colonic adaptation.

METHODS

Rats underwent one of three surgeries: control laparotomy, cecal resection, or cecal resection with placement of perfusion catheter. Rats of each surgical group were randomly assigned to receive treatment regimens of standard fiber diet (with or without fermentation-suppressing antibiotics), fiber-free diet, or diet plus intracolonic perfusion of short-chain fatty acids. Adaptation parameters of mucosal weight, mucosal DNA and protein content, water absorption, and butyrate absorption were measured.

RESULTS

Compared with controls, postresection rats that were fed fiber had 65% greater basal and 112% greater butyrate-stimulated water absorption as well as 140% greater butyrate absorption. Fiber-fed rats exhibited significantly greater colonic weight and colonic mucosal protein after cecal resection. These changes were absent in postresection rats fed a fiber-free diet. Inhibition of fermentation by neomycin and metronidazole added to a standard fiber diet also prevented postresection adaptation. All adaptive changes were restored when the cecal-resection rats that were fed the fiber diet with antibiotics received an intracolonic infusion of short-chain fatty acids. Adaptation did not occur when short-chain fatty acids were infused into colons of postresection rats that were fed a fiber-free diet.

CONCLUSIONS

Cecal resection leads to significant functional and structural changes in the adapting residual colon. Fermentation of dietary fiber by colonic flora to short-chain fatty acids is necessary, but it alone is not sufficient to mediate adaptation.

Ataxia telangiectasia and lymphoma: an indication for individualized chemotherapy dosing--report of treatment in a highly inbred Arab family

Ten of 18 children in a highly inbred Arab kindred suffered from either ataxia telangiectasia (AT) or a variant syndrome consisting of ataxia, microcephaly, and congenital cataract (AMC). Four of the nine afflicted children were treated in our unit when they developed lymphomas (both Hodgkin's and non-Hodgkin's including Burkitt's). They were given chemotherapy (either standard COMP or low-dose ABV/CVPP). The children with non-Hodgkin's lymphomas died of sepsis after receiving full-dose COMP. Low-dose ABV/CVPP brought about a 20-month remission in one child with nodular sclerosing Hodgkin's lymphoma and both AT and AMC, but she developed a preleukemic syndrome and her parents refused further treatment; she too died. A fourth child, also with nodular sclerosing Hodgkin's lymphoma, is currently in complete remission after ABV/CVPP. Treatment of lymphomas in patients with AT is extraordinarily difficult and has potential side effects so grave as to necessitate careful monitoring and individualized protocols.

Sphingosine kinase from Swiss 3T3 fibroblasts: a convenient assay for the measurement of intracellular levels of free sphingoid bases

Sphingoid bases are important for diverse cellular processes. This paper describes the development of a simple and rapid enzymatic method to quantify mass levels of free long-chain sphingoid bases in cellular lipid extracts. The assay is based on the ability of sphingosine kinase from Swiss 3T3 fibroblasts to phosphorylate sphingoid bases, predominantly sphingosine. To quantitatively determine cellular levels of sphingosine or other long-chain sphingoid bases, it was necessary to solubilize cellular lipids by sonication and to generate standard curves in the presence of lipid extracts containing at least 50 nmol of phospholipids. The assay conditions were optimized to allow quantification of sphingosine over a broad range from 25 to 1,000 pmol. Using this method we were able to obtain reproducible measurements of free sphingoid bases in various cell types and to detect increases in intracellular sphingoid base levels after treatment with exogenous sphingosine or stimulation with fetal bovine serum.

Stretch-mediated activation of cardiac renin gene

This study was designed to quantitate cardiac mRNA levels encoding components of the local renin-angiotensin system during the development of volume overload-induced cardiac hypertrophy. Changes in cardiac renin mRNA levels were measured in relation to renin activity in the left ventricle (LV) and in plasma after acute passive stretch of the heart caused by an aortovenocaval shunt in the rat. A quantitative reverse-transcriptase polymerase chain reaction method with competitive internal standards was used to measure mRNA levels in total RNA derived from cardiac tissues after shunt. Seven days after shunt surgery, LV weight was increased by 23%. Renin activities were elevated four- and twofold in plasma and LV, respectively. LV angiotensinogen mRNAs were not significantly increased by shunt surgery; they were twofold higher than phosphoglycerate kinase mRNA from the housekeeping gene PGK-1. By day 7, LV levels for renin mRNA were significantly increased from well below 0.25% to approximately 1% of PGK-1 mRNA. Identity between renin polymerase chain reaction products from kidney and heart cDNAs and absence of "reninlike" amplification products were supported by Southern blotting. Volume overload caused increased expression of the renin gene in the stretched myocardium. This finding is consistent with the concept of a myocardial renin-angiotensin system that can be activated by locally produced renin and contributes to the hypertrophy of cardiac muscle.

Localization of the VHR phosphatase gene and its analysis as a candidate for BRCA1

The VH1-related human protein (VHR) gene was localized to human chromosome 17q21 in a region thought to contain the BRCA1 locus, a locus that confers susceptibility to breast and ovarian cancer. VHR encodes a phosphatase with dual specificity for tyrosine and serine residues. Thus it is a plausible candidate for a tumor suppressor gene such as BRCA1. To test this possibility, the VHR coding sequence was screened in individuals with familial breast cancer and in sporadic breast tumor and breast cancer cell lines. No mutations were detected, suggesting that the VHR gene is not BRCA1.

Isolation of a diverged homeobox gene, MOX1, from the BRCA1 region on 17q21 by solution hybrid capture

Using the technique of solution hybridization coupled with magnetic bead capture, we have isolated a novel homeobox-containing gene from the BRCA1 region of 17q21. This gene is the human homologue of the mouse Mox1 gene previously localized to a syntenic region of mouse chromosome 11. Multiple overlapping cDNAs of human MOX1 were identified using both a cosmid and a P1 genomic clone containing the microsatellite markers D17S750 and D17S858 which map within the BRCA1 region defined by D17S776 and D17S78. MOX1 expression was observed in a variety of normal tissues examined, including breast and ovary. Given that the gene contains a homeobox domain and has the potential to regulate growth and differentiation, MOX1 represents an attractive candidate for the BRCA1 gene. This possibility was investigated in a series of BRCA1 kindreds and primary sporadic breast tumors. No evidence for mutation was found in the coding sequence, making it unlikely that MOX1 is the BRCA1 gene. However, the widespread expression of MOX1 in non-embryonal tissues suggests a role in normal cell biology which warrants further study.