Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness.

Longitudinal studies of lactate MRSI and dynamic contrast-enhanced MRI were performed at 4.7 T in two prostate tumor models grown in rats, Dunning R3327-AT (AT) and Dunning R3327-H (H), to determine the potential of lactate and the perfusion/permeability parameter Ak(ep) as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm(3) (Groups 1-5). Lactate concentration was determined using selective multiple quantum coherence MRSI with the phantom substitution method. Tumor enhancement after the administration of gadolinium diethylenetriaminepenta-acetic acid was analyzed using the Brix-Hoffmann model and the Ak(ep) parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100-270 mm(3) ). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290-700 mm(3)) to 8.4 ± 2.9 mm (Group 3; 1000-1340 mm(3)) and 8.2 ± 2.2 mm (Group 4; 1380-1750 mm(3) ), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900-2500 mm(3)), and was consistently higher in the tumor core than in the rim. Lactate was not detected in any of the H tumors. The mean tumor Ak(ep) values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Ak(ep) values were significantly higher in the rim than in the core. Histological hypoxic and necrotic fractions in AT tumors increased with volume from 0% in Group 1 to about 20% and 30%, respectively, in Group 5. Minimal amounts of hypoxia and necrosis were found in H tumors of all sizes. Thus, the presence of lactate and heterogeneous perfusion/permeability are signatures of aggressive, metabolically deprived tumors.

Control of mating preferences in mice by genes in the major histocompatibility complex.

When a male mouse is presented with two H-2 congenic two female in estrus, his choice of a mate is influenced by their H-2 types. The term "strain preference" is used to describe the general tendency of the male population of one inbred strain to prefer two female of one H-2 type rather than another. The term "consistency of choice" is used to describe the added tendency of particular two males of one inbred strain, in sequential mating trials, to prefer two females of the H-2 type they chose in previous trials. Statistical analysis showed trends in the data that support the following conclusions: (a) The choice is made by the male, not the female. (b) The strain preference of two males may favor two females of dissimilar H-2 type (four of six comparisons), or of similar H-2 type (one of six comparisons). (c) Consistency of choice does not always correspond with strain preference. In one of six comparisons of H-2 genotypes there was no strain preference but pronounced consistency of choice by individual two male. This suggests memory, but fortuitous bias is not excluded. (d) Strain preference of the same male population may favor two male of the same or a different H-2 type, depending on which different H-2 type is offered as the choice alternative to self. These findings conform to a provisional model in which olfactory mating preference is governed by two linked genes in the region of H-2, one for the female signal and one for the male receptor. These mating preferences could in natural populations serve the purpose of increasing the representation of particular H-2 haplotypes or of maintaining heterozygosity of genes in the region of H-2.

Decreased growth of established human prostate LNCaP tumors in nude mice fed a low-fat diet.

BACKGROUND: Geographic variation in the incidence of clinically detected prostate cancer is considerable, with a 120-fold greater incidence in the United States than in China. The incidence of latent prostate cancer, however, shows little variation worldwide, with approximately 30% of men older than age 50 years having microfocal disease (determined by autopsy). Some epidemiologic studies have suggested that a high intake of dietary fat may constitute a risk factor for the development of advanced prostate cancer. PURPOSE: We studied the influence of dietary fat content on the growth of tumors established in athymic nude mice with androgen-sensitive, human prostatic adenocarcinoma cells (LNCaP cells). We also investigated whether manipulation of dietary fat content altered prostate-specific antigen (PSA) production by these tumors. METHODS: Tumors were induced in nude mice by subcutaneous injection of 10(6) LNCaP cells. Both the American Type Culture Collection (ATCC) LNCaP cell line and a more androgen-responsive subline derived from it (i.e., the Harris LNCaP cell line) were used. Mice were fed a 40.5-kcal% fat diet at the time of tumor cell injection. Three weeks later, after measurable tumors were formed, the animals were assigned to receive diets with one of the following fat contents: 40.5, 30.8, 21.2, 11.6, or 2.3 kcal% fat. Food intake, animal weights, and tumor volumes were recorded weekly; serum PSA and testosterone levels were measured at the termination of the study. Post hoc multiple comparisons were made using the Student-Newman-Keuls procedure. Two-sided tests of statistical significance were used to evaluate pairwise comparisons. RESULTS: Tumor growth rates, final tumor weights, and ratios of final tumor weights to animal weights were substantially greater in groups that continued to receive a 40.5-kcal% fat diet than in groups whose diets were changed to 2.3 kcal%, 11.6 kcal%, or 21.2 kcal% fat (all P values < .04). Comparison of these parameters among the 2.3-kcal%, 11.6-kcal%, and 21.2-kcal% dietary fat groups did not reveal any statistically significant differences. No statistically significant differences were noted in total ingested calories, animal weight gain, serum testosterone levels, or histopathologic characteristics of the tumors among the tested dietary groups. Serum PSA levels were highest in the 40.5-kcal% fat group and lowest in the 2.3-kcal% fat group (evaluated only for ATCC LNCaP cells; P < .05). CONCLUSIONS: Reduction of dietary fat substantially slows the growth of tumors established from human prostatic adenocarcinoma cells in a murine xenograft model. A positive association persists between tumor volumes and serum PSA levels even after extreme modification of dietary fat content.

Prostaglandins in cells of the lymphoid system in AKR leukemia.

AKR mice develop spontaneous lymphoid leukemia late (8 to 12 months) in life, although persistent murine leukemia virus production occurs throughout their life. This suggests that age-related changes are involved in development of leukemia. Prostaglandin biosynthesis was therefore studied in 24-hr cultures in vitro at 37 degrees of peritoneal macrophages, splenocytes, thymocytes, bone marrow, and lymph node cells. AKR mice of 2, 6, and 8 to 12 months of age were studied. Prostaglandin E1, prostaglandin E2, prostaglandin F2 alpha, 6-ketoprostaglandin F1 alpha, and thromboxane B2 were measured. In cultures of peritoneal macrophages and cells from spleen, thymus, and lymph nodes, the biosynthesis of all five prostaglandin moieties was higher in those cultures prepared from 8- to 12-month-old spontaneously leukemic mice in comparison with those from 2-month-old nonleukemic AKR mice. However, when leukemia was transplanted in 3-month-old AKR mice, synthesis of all five compounds was reduced significantly in cultures of peritoneal macrophages and splenocytes prepared from these 3-month-old leukemic mice. The present data demonstrate abnormalities in prostaglandin synthesis by various cells of the immune system in leukemic mice. However, the nature of these changes was different in cultures of cells from spontaneously leukemic mice from those with transplanted leukemia. Age-related increases in prostaglandin synthesis by various lymphoid cells from spontaneously leukemic AKR mice (8 to 12 months old) occurred at a much earlier age than in BALB/c mice and may be related to the leukemic condition.

Suberoylanilide hydroxamic acid, an inhibitor of histone deacetylase, suppresses the growth of prostate cancer cells in vitro and in vivo.

Suberoylanilide hydroxamic acid (SAHA) is the prototype of a family of hybrid polar compounds that induce growth arrest in transformed cells and show promise for the treatment of cancer. SAHA induces differentiation and/or apoptosis in certain transformed cells in culture and is a potent inhibitor of histone deacetylases. In this study, we examined the effects of SAHA on the growth of human prostate cancer cells in culture and on the growth of the CWR22 human prostate xenograft in nude mice. SAHA suppressed the growth of the LNCaP, PC-3, and TSU-Pr1 cell lines at micromolar concentrations (2.5-7.5 microM). SAHA induced dose-dependent cell death in the LNCaP cells. In mice with transplanted CWR222 human prostate tumors, SAHA (25, 50, and 100 mg/kg/day) caused significant suppression of tumor growth compared with mice receiving vehicle alone; treatment with 50 mg/kg/day resulted in a 97% reduction in the mean final tumor volume compared with controls. At this dose, there was no detectable toxicity as evaluated by weight gain and necropsy examination. Increased accumulation of acetylated core histones was detected in the CWR22 tumors within 6 h of SAHA administration. SAHA induced prostate-specific antigen mRNA expression in CWR22 prostate cancer cells, resulting in higher levels of serum prostate-specific antigen than predicted from tumor volume alone. The results suggest that hydroxamic acid-based hybrid polar compounds inhibit prostate cancer cell growth and may be useful, relatively nontoxic agents for the treatment of prostate carcinoma.

Prospective assessment of white matter integrity in adult stem cell transplant recipients.

Hematopoietic stem cell transplantation (HSCT) is often used in the treatment of hematologic disorders. Although it can be curative, the pre-transplant conditioning regimen can be associated with neurotoxicity. In this prospective study, we examined white matter (WM) integrity with diffusion tensor imaging (DTI) and neuropsychological functioning before and one year after HSCT in twenty-two patients with hematologic disorders and ten healthy controls evaluated at similar intervals. Eighteen patients received conditioning treatment with high-dose (HD) chemotherapy, and four had full dose total body irradiation (fTBI) and HD chemotherapy prior to undergoing an allogeneic or autologous HSCT. The results showed a significant decrease in mean diffusivity (MD) and axial diffusivity (AD) in diffuse WM regions one year after HSCT (p-corrected <0.05) in the patient group compared to healthy controls. At baseline, patients treated with allogeneic HSCT had higher MD and AD in the left hemisphere WM than autologous HSCT patients (p-corrected <0.05). One year post-transplant, patients treated with allogeneic HSCT had lower fractional anisotropy (FA) and higher radial diffusivity (RD) in the right hemisphere and left frontal WM compared to patients treated with autologous HSCT (p-corrected <0.05).There were modest but significant correlations between MD values and cognitive test scores, and these were greatest for timed tests and in projection tracts. Patients showed a trend toward a decline in working memory, and had lower cognitive test scores than healthy controls at the one-year assessment. The findings suggest a relatively diffuse pattern of alterations in WM integrity in adult survivors of HSCT.

Expression of transforming growth factor alpha in human gliomas.

Expression of transforming growth factor alpha (TGF alpha) is frequently associated with the development of human and animal tumors. Using a sensitive immunohistochemical assay, which can be applied on formalin-fixed, paraffin-embedded tissue, we have examined the expression of TGF alpha in 71 human gliomas (63 untreated and 8 recurrent tumors). Tumors were graded by a 3-grade-system: grade I = low grade gliomas, grade II = anaplastic gliomas and grade III = glioblastomas. A strong positive correlation between tumor grade and extent of TGF alpha expression was found (P less than 0.0001). Polymerase chain reaction (PCR) was used to amplify the fourth exon of the TGF alpha gene of 8 glioma DNA specimens and increasing amounts of normal human DNA, which served as a standard. No amplification of the TGF alpha gene copy number in tumors could be detected.

Combined modality therapy for primary CNS lymphoma.

PURPOSE: Primary CNS lymphoma (PCNSL), formerly rare, is being seen with increased frequency among apparently immunocompetent patients. Conventional treatment has consisted of whole-brain radiotherapy (RT) and corticosteroids, with a median survival of 15 to 18 months and a 3% to 4% 5-year survival. Chemotherapy has been useful in the treatment of recurrent PCNSL. In 1985 we began a treatment protocol using chemotherapy and cranial irradiation for the initial therapy of non-AIDS PCNSL. PATIENTS AND METHODS: Thirty-one patients (group A) completed the combined modality regimen. All had placement of an Ommaya reservoir and received pre-RT systemic methotrexate, 1 g/m2, plus six doses of intra-Ommaya methotrexate at 12 mg per dose. A full course of cranial RT (4,000-cGy whole-brain RT plus a 1,440-cGy boost) was followed by two cycles of high-dose cytarabine (ara-C), with each course consisting of two doses of 3 g/m2 ara-C separated by 24 hours and infused over 3 hours. During this period, 16 additional patients (group R) were treated with RT alone, either because patients refused chemotherapy or RT was initiated before our consultation; all would have been eligible to participate in the protocol. Follow-up extended through April 1, 1991. RESULTS: Group A had a significantly prolonged time to recurrence (median, 41 months) compared with group R (median, 10 months; P = .003). Although median survival was doubled from 21.7 months for group R to 42.5 months for group A, this was not statistically significant because of small sample size. More importantly, group R patients received systemic chemotherapy for recurrent PCNSL, which improved survival. CONCLUSION: The addition of chemotherapy to cranial RT for initial treatment of PCNSL significantly improved disease-free survival and contributed to overall survival; all non-AIDS patients with newly diagnosed PCNSL should be considered for combined modality therapy.

Pain and depression in patients with newly diagnosed pancreas cancer.

PURPOSE: To evaluate the prevalence of pain and depression, their correlation, and their effect on quality of life in patients with recently diagnosed adenocarcinoma of the pancreas (PC). MATERIALS AND METHODS: Cross-sectional pain and psychosocial distress were assessed using validated instruments, including the Memorial Pain Assessment Card (MPAC), Beck Depression Inventory (BDI), Hopelessness Scale (BHS), and Functional Living Index-Cancer (FLIC). Patients were evaluated before their first operation for PC or first treatment with chemotherapy at a large tertiary-care cancer center. RESULTS: One hundred thirty patients with proven PC were studied: 83 before their operation and 47 before their first chemotherapy treatment. At the time of study entrance, 37% of patients had no pain and an additional 34% had pain that was mild or less severe. Only 29% of patients had moderate, strong, or severe pain. Chemotherapy patients reported significantly more intense pain than did preoperative patients (P = .02). Symptoms of depression were assessed using the BDI and BHS scales. A substantial minority of patients (38%) had BDI scores > or = 15, which suggests high levels of depressive symptoms. There was a significant correlation between increasing pain and depressive symptoms among those who experienced pain. Quality of life was assessed using the Weekly Activity Checklist (WAC) and the FLIC. Compared with patients who had no pain or mild pain, patients with moderate or greater pain had significantly impaired functional activity (P = .03) and poorer quality-of-life scores (P = .02) when compared with those with lesser degrees of pain. There were significant correlations between increasing pain and depression and between pain and depressive symptoms and impaired quality of life and function. CONCLUSION: Our results indicate that moderate or severe pain and symptoms of depression are not as prevalent in recently diagnosed PC patients as is generally believed. However, one third have inadequate pain control despite the use of oral analgesics. These patients can be identified by the use of a simple self-report instrument (the MPAC card). Quality of life and function are adversely affected by moderate or greater levels of perceived pain intensity. A simple and rapid assessment is possible and can identify high-risk patients in need of intervention that may improve quality of life.

Neuropsychological characterization of the AIDS dementia complex: a preliminary report.

The AIDS dementia complex (ADC) is a frequent complication of advanced HIV infection. In order to better define the neuropsychological character and progression of the ADC, four groups of subjects were studied with a battery of neuropsychological tests: an HIV-seronegative comparison group (n = 20), asymptomatic HIV-seropositive patients (n = 16), newly diagnosed AIDS patients (n = 44) and AIDS patients who were referred for neurological consultation (n = 40). Results showed significant reductions in performance in the two AIDS groups, with impairment being most prominent in tests that assessed motor speed and fine control, concentration, problem solving and visuospatial performance. This pattern of neuropsychological dysfunction is consistent with the characterization of the ADC as a subcortical dementia.

Effects of xenon and krypton on regional cerebral blood flow in the rat.

The effects of high inspired concentrations of xenon and krypton on regional CBF (rCBF) were assessed in the rat using [14C]iodoantipyrine and quantitative autoradiography. Inhalation of 80% xenon for 1 or 2 min and inhalation of 40% xenon for 2 min were found to have significant effects on rCBF, including average increases of 75-96% in cerebral neocortical regions. Inhalation of 40% xenon for 1 min and of 80% krypton for 2 min had no significant effect on rCBF in most brain regions studied. If xenon inhalation produces effects on rCBF in humans similar to those observed in the rat, such effects could be an important source of error in xenon computed tomography rCBF studies.

Repeated least squares analysis of simulated xenon computed tomographic measurements of regional cerebral blood flow.

Computer simulations were done as a feasibility study of xenon computed tomographic measurements of regional cerebral blood flow. Accuracy of initial least squares estimates of gray matter and white matter rate constants from a two-compartment model depended very little on the number and timing of scans, but did depend significantly on the enhancement-to-noise ratio as well as on the true values of the rate constants and gray/white ratio. Nonlinear least squares gives an optimal fit of the predicted wash-in--wash-out curve to the data rather than optimal estimates of the rate constants. A polynomial correction factor was obtained by regressing initial estimates on the true values used to generate the simulations. The correction factor substantially reduced error in the estimates and, in particular, eliminated large outliers.

The metabolite morphine-6-glucuronide contributes to the analgesia produced by morphine infusion in patients with pain and normal renal function.

Morphine-6-glucuronide is a metabolite of morphine that binds to the opioid receptor and is analgesic in animals and humans. Although accumulation of morphine-6-glucuronide in patients with renal insufficiency has been implicated in morphine toxicity, the contribution of the metabolite to morphine analgesia in patients with normal renal function has not been established. To evaluate this contribution, we repeatedly sampled blood and assessed effects during and after a loading infusion with morphine (mean duration, 168 minutes) in 14 patients with chronic pain, all of whom had normal serum creatinine levels. Plasma concentrations of morphine and morphine-6-glucuronide were assayed by use of high performance liquid chromatography with electrochemical detection. Patients were divided into three groups on the basis of the molar concentration ratio of morphine-6-glucuronide:morphine from the start of the infusion until 240 minutes later: Group 1 (n = 5) had a mean ratio greater than or equal to 0.7:1; group 2 (n = 4) had a mean ratio less than 0.7:1 but greater than or equal to 0.4:1; and group 3 (n = 5) had a mean ratio less than 0.4:1. Time-effect plots revealed that average and peak relief were greater in group 1 than group 2 and greater in group 2 than group 3. For all patients, mean morphine-6-glucuronide:morphine ratio throughout the study was significantly correlated with mean pain relief (r = 0.611, p less than 0.02). These data suggest that morphine-6-glucuronide contributes to morphine analgesia in patients with normal renal function. The role of the metabolite should be considered when morphine is used clinically.

Distribution of brain metastases.

The number and site of brain metastases were identified on the computed tomographic scans of 288 patients. There was one brain metastasis in 49%, two in 21%, three in 13%, four in 6%, and five or more in 11% of scans. In patients with one metastasis, the posterior fossa was involved in 50% of patients when the primary tumor was pelvic (prostate or uterus) or gastrointestinal, but it was involved in only 10% of patients with other primary tumors. Hemispheral metastases preferred the anatomic "watershed areas" (29% of the brain surface contained 37% of the metastases), indicating that tumoral microemboli tend to lodge in the capillaries of the distal parts of the superficial arteries. The charts of 134 patients with brain metastases from a primary tumor originating outside the lung revealed that the incidence of lung and spine metastases was the same, whether the primary tumor was pelvic or gastrointestinal or from another site. These data suggest that the high incidence of subtentorial lesions in patients with pelvic and gastrointestinal primary tumors cannot be explained by arterial embolization alone, and that this peculiar distribution is probably not explained by seeding of the brain through Batson's plexus.

Perforation of the gastrointestinal tract in patients receiving steroids for neurologic disease.

Between 1980 and 1984, of 107 patients receiving 16 mg/d of dexamethasone for spinal cord compression, three (2.8%) developed gastrointestinal (GI) perforation and two (1.9%) GI bleeding; of 226 being tapered from 100 mg/d of dexamethasone, perforation occurred in six (2.7%) and GI bleeding in eight (3.5%). Of 125 patients with GI perforations treated between 1979 and 1986, 41 (33%) were on steroids, 24 for neurologic disease. Median duration of steroid therapy was 24 days; 20 (91%) of the neurologic patients perforated within 30 days. The steroid group had more free peritoneal involvement (p less than 0.00001), but fewer signs and symptoms of peritonitis (p less than 0.000001) than the nonsteroid group. Seventeen patients were receiving steroids for cord compression; they had significantly more rectosigmoid perforations (p less than 0.014) and associated constipation (p less than 0.000001) than the 108 remaining patients. GI perforation is a less well-recognized complication of steroid therapy in neurologic patients than is GI bleeding though it occurs as frequently, is more difficult to diagnose, and far more serious. In steroid-treated patients, prevention of constipation might avert this serious complication, while early diagnosis will improve the outcome.

Adult brainstem gliomas.

OBJECTIVE: To evaluate prognostic factors and survival of adult patients with brainstem gliomas. BACKGROUND: Brainstem glioma is a disease found primarily in children, with a median survival of only 9 to 12 months. However, the prognosis and survival of adults with this disease has not been determined with precision. METHODS: We conducted a retrospective analysis of patients older than 16 years at Memorial Sloan-Kettering Cancer Center with histologically proved or presumed brainstem glioma diagnosed between 1989 and 1997. We assessed the effect of gender, age at diagnosis, cranial nerve involvement, duration of symptoms, exophytic component, MRI enhancement, site of disease, treatment, and Karnofsky performance status on survival. RESULTS: Twenty-three patients were identified, but complete information was available in only 19 (12 males and 7 females). Patients ranged in age from 17 to 70 years (median, 40 years). Twelve patients were treated with radiotherapy at diagnosis and seven were observed, three of whom received subsequent radiotherapy. Median survival is 54 months (range, 3 to 98 months) and the 5-year survival is 45%. There was a trend for patients with a higher performance status at diagnosis to have longer survival, but this did not reach statistical significance. Other factors did not affect survival. CONCLUSION: Adults with brainstem gliomas may survive significantly longer than children, suggesting the disease may be less aggressive in adults. Furthermore, some patients with a long duration of symptoms or tectal or cervicomedullary tumors may be managed initially with observation alone.

The role of radiation therapy following resection of single brain metastasis from melanoma.

From 1972 to 1987, 35 patients underwent resection of a single brain metastasis from melanoma; 19 received postoperative radiation therapy (RT) (group A), and 16 did not (group B). Group A had a longer interval to CNS relapse compared with group B, but survival was similar. However, 4/17 (24%) from group A and 11/13 (85%) from group B died of neurologic causes. We conclude that patients with single brain metastasis from melanoma have improved control of CNS disease when postoperative RT is administered, and survival depends upon control of systemic disease.

Primary CNS lymphoma: combined treatment with chemotherapy and radiotherapy.

Primary central nervous system lymphoma (PCNSL), an uncommon tumor, is occurring with increasing frequency. Conventional therapy with corticosteroids and cranial radiotherapy (RT) usually gives a dramatic initial response, but median survival is only 10 to 18 months. Chemotherapy is more successful in comparable systemic lymphoma and has been employed for PCNSL at relapse, causing remission but not cure. Between June 1985 and June 1988, we prospectively staged 32 patients with PCNSL at Memorial Sloan-Kettering Cancer Center and treated 28 on a new protocol that combined chemotherapy and radiotherapy at diagnosis. None had occult systemic lymphoma, but 19% had ocular and 69% had definite or probable leptomeningeal lymphoma. There were no complications in 19 stereotactic biopsies, but 4/10 patients who had a complete resection suffered a severe postoperative deficit. Four patients received RT alone, and 28 received chemotherapy and cranial RT, 17 of whom (group A) received a combination regimen using pre-RT systemic (1 g/m2) and intra-Ommaya methotrexate (MTX), 4,000 cGy whole-brain RT with a 1,440 cGy boost, and 2 courses of post-RT high-dose cytosine arabinoside; 5 other patients received an identical regimen but with a decreased dose of MTX (200 mg/m2). Sixty-three percent of assessable patients had a response to MTX independent of corticosteroid and prior to RT. Eighteen of 26 (69%) assessable patients who received combined therapy are alive with a median follow-up of 25.4 months. Twelve of 16 (75%) assessable group A patients are alive in the same period. Chemotherapy-related toxicity was minimal, and no late toxicities have occurred to date.(ABSTRACT TRUNCATED AT 250 WORDS)

Steroid myopathy in cancer patients.

We prospectively evaluated 15 adult cancer patients being treated with adrenocorticosteroids (steroids) to determine the frequency and time course of "steroid myopathy." Nine (60%) developed clinically detectable proximal muscle weakness that, in six, was severe enough to interfere with activities of daily living. Proximal muscle weakness developed within 15 days in eight of nine patients and was significantly related to the cumulative dose of steroid. Eight of nine patients with proximal muscle weakness, and two of six without such weakness, experienced a significant decline in respiratory function, leading to symptomatic dyspnea in four patients of the former group. In three patients who could be followed for more than 3 months off steroids, there was either improvement or resolution of the weakness and, when present, of the respiratory impairment. Steroid myopathy is a common complication among cancer patients receiving steroids. It can often affect respiratory function even when proximal limb muscles remain strong. Clinical recognition is important since steroid myopathy can lead to increased morbidity and may be reversible with reduction or discontinuation of steroids.

Chronic morphine therapy for cancer pain: plasma and cerebrospinal fluid morphine and morphine-6-glucuronide concentrations.

Morphine-6-glucuronide (M-6-G) is an active metabolite that may contribute to the clinical effects produced by systemic administration of morphine. To help clarify the extent to which M-6-G may cross the blood-brain barrier and exert effects, we employed high-performance liquid chromatography with electrochemical detection to measure the concentrations of M-6-G and morphine in the plasma and either ventricular (three patients) or lumbar (eight patients) CSF of cancer patients receiving chronic morphine therapy. The mean ratio of morphine in ventricular CSF:morphine in plasma was 0.71; the same ratio for M-6-G was only 0.077. The average molar ratio of M-6-G: morphine in ventricular CSF was 0.207, and the average molar ratio in plasma was 1.89. Although sampling problems render the lumbar CSF results less reliable, they were very similar. Thus, plasma contained approximately twice as much M-6-G as morphine, whereas CSF contained only one-fifth to one-third as much. These data confirm that M-6-G in plasma is distributed into CSF, but to a far lesser extent than morphine. They help explain animal data demonstrating much higher potency of M-6-G on administration into CSF than systemic administration and indicate that the degree to which M-6-G contributes to morphine effects in humans remains an unresolved question.