The anion gap and routine serum protein measurements in monoclonal gammopathies

BACKGROUND AND OBJECTIVES

An abnormal anion gap and an increased total protein and globulin are clues to the diagnosis of monoclonal gammopathy. We explored the utility of these markers in IgG, IgA, IgM, and free light chain monoclonal gammopathies.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The anion gap, Na(+) - (Cl(-) + HCO(3)(-)), corrected for hypoalbuminemia, was calculated in patients with monoclonal gammopathies. Exclusion criteria were serum calcium >10.5 mg/dl and/or creatinine >2 mg/dl.

RESULTS

Among 287 patients, 242 remained after applying exclusion criteria (109 IgG, 64 IgA, 21 IgM, and 48 light chain); 36% of 242 patients required correction for hypoalbuminemia. The anion gap was decreased (<10) in 22% of IgG and increased (>15) in 31% of IgA monoclonal gammopathies. IgM did not affect the gap. In light chain gammopathies, the anion gap showed no consistent trend (15% increased, 17% decreased). Mean clonal IgG, IgA, and IgM concentrations were 10-fold higher than mean clonal free light chain concentrations in the respective monoclonal gammopathies (P < 0.001). These paraprotein level disparities were reflected in significantly increased mean serum total protein and globulin concentrations in IgG, IgA, and IgM versus free light chain monoclonal gammopathies, where mean total protein and globulin levels were within normal limits (P < 0.001).

CONCLUSIONS

The anion gap was significantly altered in IgG and IgA monoclonal gammopathies, but it was not a sensitive tool for suspecting the diagnosis. In light chain monoclonal gammopathies, the anion gap, total protein, and globulin did not provide reliable diagnostic clues.

MMX mesalazine for the induction of remission of mild-to-moderately active ulcerative colitis: efficacy and tolerability in specific patient subpopulations

BACKGROUND

Two phase III studies have evaluated mesalazine (mesalamine) with MMX (Multi Matrix System) technology in patients with active mild-to-moderate ulcerative colitis.

AIM

To determine the efficacy of MMX mesalazine for the induction of clinical and endoscopic remission in specific subgroups of patients with active, mild-to-moderate ulcerative colitis.

METHODS

Data from two double-blind, placebo-controlled trials were analysed (517 out-patients). Patients were randomized to receive MMX mesalazine [2.4 g/day (once daily or 1.2 g twice daily) or 4.8 g/day (once daily)] or placebo for 8 weeks.

RESULTS

The percentages of patients treated with MMX mesalazine, 2.4 or 4.8 g/day, in clinical and endoscopic remission at week 8 were similar and significantly (P < 0.05) greater than placebo in subgroups stratified by disease extent, disease severity and gender and among patients not previously receiving low-dose 5-aminosalicylic acid. Among patients transferring directly from prior low-dose oral 5-aminosalicylic acid, MMX mesalazine 4.8 g/day was significantly (P = 0.018) more effective than placebo in inducing clinical and endoscopic remission. Efficacy over placebo did not reach significance in patients transferring directly to MMX mesalazine 2.4 g/day.

CONCLUSION

MMX mesalazine is effective in active UC regardless of disease extent, disease severity, gender and previous, low-dose, 5-ASA therapy.

MMX Multi Matrix System mesalazine for the induction of remission in patients with mild-to-moderate ulcerative colitis: a combined analysis of two randomized, double-blind, placebo-controlled trials

MMX mesalazine [LIALDA (US), MEZAVANT XL (UK and Ireland) MEZAVANT (elsewhere)] utilizes MMX Multi Matrix System (MMX) technology which delivers mesalazine throughout the colon. Two phase III studies have already evaluated MMX mesalazine in patients with active, mild-to-moderate ulcerative colitis. Aim To provide more precise estimates of the efficacy of MMX mesalazine over placebo by combining the patient populations from the two phase III studies. Methods Combined data from two 8-week, double-blind, placebo-controlled trials were analyzed. Patients randomized to MMX mesalazine 2.4 g/day (once daily or 1.2 g twice daily), 4.8 g/day (once daily) or placebo were reviewed. The primary end point was clinical and endoscopic remission (modified Ulcerative Colitis-Disease Activity Index of </=1 calculated as: rectal bleeding and stool frequency scores of 0, a combined Physician's Global Assessment and sigmoidoscopy score of </=1, no mucosal friability and a >/=1-point reduction in sigmoidoscopy score from week 0). Results Data from 517 patients were analysed. 8-week remission rates were 37.2% and 35.1% in the MMX mesalazine 2.4 g/day and 4.8 g/day groups, vs. 17.5% on placebo (P < 0.001, both comparisons). 8-week complete mucosal healing rates were 32% in both MMX mesalazine groups compared with 16% on placebo. Adverse event frequency was similar in all groups. Conclusion MMX mesalazine is effective and generally well tolerated for inducing clinical and endoscopic remission of active, mild-to-moderate ulcerative colitis.

Plasmapheresis treatment of recurrent FSGS in adult renal transplant recipients

Plasmapheresis (PP) is often employed in the treatment of recurrent focal segmental glomerulosclerosis (FSGS) in the renal allograft, where it appears to be effective in the pediatric population. The efficacy of PP in adults and predictors of response are not well documented. We analyzed the records of 13 adult patients from three transplant centers who underwent PP for recurrent FSGS between 1993 and 1999. One patient (8%) had a complete response, one (8%) had a partial response, and 3 (23%) partially responded but remain PP-dependent. All 5 responders were started on PP within 30 days of recurrence, while 7 of the 8 non-responders initiated PP after a delay of at least 42 days (p = 0.0047). FSGS recurred within 30 days of transplantation in all 5 responders, while 4 of 8 non-responders had no evidence of recurrence until 42-150 days after transplantation (p = 0.098). Post-transplant biopsies were examined in 10 patients and revealed either cellular (6) or collapsing (4) variants of FSGS. We conclude PP is less effective in adults than in children as a treatment for recurrent FSGS in the renal allograft. Predictors of response to PP include early initiation of treatment after recurrence and possibly an early recurrence of disease.

Antiphospholipid antibody syndrome and renal disease

The antiphospholipid syndrome is a disorder of hypercoagulability in association with circulating antiphospholipid antibodies directed against epitopes on oxidized phospholipids complexed with a glycoprotein, beta 2-glycoprotein I, or against the glycoprotein itself. Disorders associated with antiphospholipid antibodies but not the antiphospholipid syndrome, such as HIV and hepatitis C infection, appear to lack antibodies to beta 2-glycoprotein I. Patients with systemic lupus erythematosus have a high incidence of antiphospholipid antibodies with a high risk of thrombosis, often associated with anticardiolipin antibodies, beta 2-glyocoprotein I antibodies, and the presence of the lupus anticoagulant. Antiphospholipid antibodies are a significant cause of morbidity and mortality in renal patients with and without systemic lupus erythematosus. Renal manifestations include thrombotic microangiopathy and large vessel thrombosis. In patients with end-stage renal disease, antiphospholipid antibodies are prevalent and may increase in frequency with time on dialysis, possibly as a result of oxidative stress incurred during dialysis. The presence of anticardiolipin antibodies have been associated with a high incidence of hemodialysis access clotting. In renal transplant recipients, the incidence of antiphospholipid antibodies is also elevated and may be associated with a higher incidence of primary graft non-function. Although patients with systemic lupus erythematosus have similar renal allograft survival rates to the general population, survival is worse for those patients who are also antiphospholipid antibody positive. Additionally, in hepatitis C positive renal transplant recipients, the presence of anticardiolipin antibodies confers an increased risk of thrombotic complications and the development of thrombotic microangiopathy. Treatment of antiphospholipid antibody syndrome remains centered around anticoagulation with warfarin. The use of immunosuppressive agents has had no dramatic effect on antiphospholipid antibody titers and little clinical effect on thrombotic events.

The disposition of cocaine and opiate analytes in hair and fingernails of humans following cocaine and codeine administration

This study investigated the disposition patterns of cocaine and opiates into hair and fingernail specimens collected from 8 volunteers enrolled in a 10-week inpatient clinical study. All subjects were African-American males with a confirmed drug use history. Scalp hair and fingernail scrapings were collected weekly throughout the course of the study. Head hair was collected from the posterior vertex region, and fingernail scrapings were collected along the entire ventral surface of the nail plate. The specimens were introduced to successive decontamination washes including an isopropanol wash and three phosphate buffer washes. All decontamination washes were collected and analyzed. All specimens were enzymatically digested prior to being subjected to solid-phase extraction and derivatization. Analyses were performed using electron impact gas chromatography-mass spectrometry. Analytes investigated included eight cocaine analytes and five codeine analytes. The limit of quantitation for all analytes ranged from 0.1 to 0.5 ng/mg for both matrices. Cocaine was present at the highest concentrations of any analyte in both hair and nail. Benzoylecgonine and ecgonine methyl ester were the primary metabolites in both matrices and were typically less than 15% of cocaine concentrations. Codeine was the only opiate analyte identified in either hair or nail. Observed drug disposition profiles were different for hair and nails. A significant dose-response relationship was observed for hair specimens. The mean peak concentrations in hair after low dosing were half the concentration observed after high-dose administration. Generally, no clear relationship was evident between nail drug concentrations and dose. Decontamination washes removed less than 20% of the total drug present in hair, but removed most of the drug concentrations (60-100%) in nail. This investigation demonstrated that higher concentrations of drug were found in the subjects' hair than in their fingernails and that cocaine was found in both matrices at a greater concentration than codeine. Although both hair and nail have similar physical and chemical properties and may share common mechanisms of drug incorporation, this clinical study suggests that there are distinct differences in their disposition profiles.

Identification of hydrocodone in human urine following controlled codeine administration

Allegations of illicit hydrocodone use have been made against individuals who were taking physician-prescribed oral codeine but denied hydrocodone use. Drug detection was based on positive urine opiate immunoassay results with subsequent confirmation of hydrocodone by gas chromatography-mass spectrometry (GC-MS). In these cases, low concentrations of hydrocodone (approximately 100 ng/mL) were detected in urine specimens containing high concentrations of codeine (> 5000 ng/mL). Although hydrocodone has been reported to be a minor metabolite of codeine in humans, there has been little study of this unusual metabolic pathway. We investigated the occurrence of hydrocodone excretion in urine specimens of subjects who were administered codeine. In a controlled study, two African-American and three Caucasian male subjects were orally administered 60 mg/70 kg/day and 120 mg/70 kg/day of codeine sulfate on separate days. Urine specimens were collected prior to and for approximately 30-40 h following drug administration. In a second case study, a postoperative patient self-administered 960 mg/day (240 mg four times per day) of physician-prescribed oral codeine phosphate, and urine specimens were collected on the third day of the dosing regimen. Samples from both studies were extracted on copolymeric solid-phase columns and analyzed by GC-MS. In the controlled study, codeine was detected in the first post-drug-administration specimen from all subjects. Peak concentrations appeared at 2-5 h and ranged from 1475 to 61,695 ng/mL. Codeine was detected at concentrations above the 10-ng/mL limit of quantitation for the assay throughout the 40-h collection period. Hydrocodone was initially detected at 6-11 h following codeine administration and peaked at 10-18 h (32-135 ng/mL). Detection times for hydrocodone following oral codeine administration ranged from 6 h to the end of the collection period. Confirmation of hydrocodone in a urine specimen was always accompanied by codeine detection. Codeine and hydrocodone were detected in all specimens collected from the postoperative patient, and concentrations ranged from 2099 to 4020 and 47 to 129 ng/mL, respectively. Analyses of the codeine formulations administered to subjects revealed no hydrocodone present at the limit of detection of the assay (10 ng/mL). These data confirm that hydrocodone can be produced as a minor metabolite of codeine in humans and may be excreted in urine at concentrations as high as 11% of parent drug concentration. Consequently, the detection of minor amounts of hydrocodone in urine containing high concentrations of codeine should not be interpreted as evidence of hydrocodone abuse.

Sweat testing for cocaine, codeine and metabolites by gas chromatography-mass spectrometry

Sweat testing for drugs of abuse provides a convenient and considerably less invasive method for monitoring drug exposure than blood or urine. Numerous devices have been developed for collection of sweat specimens. The most common device in current use is the PharmChek Sweat Patch, which usually is worn by an individual for five to ten days. This device has been utilized in several field trials comparing sweat test results to conventional urinalysis and the results have been favorable. Two new Fast Patch devices have been developed and tested that allow rapid collection of sweat specimens. The Hand-held Fast Patch was applied to the palm of the hand and the Torso Fast Patch was applied to the abdomen or the sides of the trunk (flanks) of volunteer subjects participating in a research study. Both patches employed heat-induced sweat stimulation and a larger cellulose pad for increased drug collection. Sweat specimens were collected for 30 min at various times following administration of cocaine or codeine in controlled dosing studies. After patch removal, the cellulose pad was extracted with sodium acetate buffer, followed by solid-phase extraction. Extracts were derivatized and analyzed by gas chromatography mass spectrometry (GC-MS) simultaneously for cocaine, codeine and metabolites. Cocaine and codeine were the primary analytes detected in sweat. Peak cocaine and codeine concentrations ranged from 33 to 3579 ng/patch and 11 to 1123 ng/patch, respectively, across all doses for the Hand-held Patch compared to 22-1463 ng/patch and 12-360 ng/patch, respectively, for the Torso Fast Patch. Peak concentrations generally occurred 4.5-24 h after dosing. Both drugs could be detected for at least 48 h after dosing. Considerably smaller concentrations of metabolites of cocaine and codeine were also present in some patches. Generally, concentrations of cocaine and codeine were higher in sweat specimens collected with the Hand-held Fast Patch than for the Torso Fast Patch. Drug concentrations were also considerably higher than those reported for the PharmChek Sweat Patch. The predominance of cocaine and codeine in sweat over metabolites is consistent with earlier studies of cocaine and codeine secretion in sweat. Multiple mechanisms appear to be operative in determining the amount of drug and metabolite secreted in sweat including passive diffusion from blood into sweat glands and outward transdermal migration of the drug. Additional important factors are the physico-chemical properties of the drug analyte, specific characteristics of the sweat collection device, site of sweat collection and, in this study, the application of heat to increase the amount of drug secreted.

Drug testing with alternative matrices II. Mechanisms of cocaine and codeine deposition in hair

A 10-week inpatient study was performed to evaluate cocaine, codeine, and metabolite disposition in biological matrices collected from volunteers. An initial report described drug disposition in plasma, sebum, and stratum corneum collected from five African-American males. This report focuses on drug disposition in hair and sweat collected from the same five subjects. Following a three-week washout period, three doses of cocaine HCl (75 mg/70 kg, subcutaneous) and three doses of codeine SO4 (60 mg/70 kg, oral) were administered on alternating days in week 4 (low-dose week). The same dosing sequence was repeated in week 8 with doubled doses (high-dose week). Hair was collected by shaving the entire scalp once each week. Hair from the anterior vertex was divided into two portions. One portion was washed with isopropanol and phosphate buffer; the other portion was not washed. Hair was enzymatically digested, samples were centrifuged, and the supernatant was collected. Sweat was collected periodically by placing PharmChek sweat patches on the torso. Drugs were extracted from sweat patches with methanol/0.2 M sodium acetate buffer (75:25, v/v). Supernatants from hair digests, hair washes, and sweat patch extracts were processed by solid-phase extraction followed by gas chromatography-mass spectrometry analysis for cocaine, codeine, 6-acetylmorphine, and metabolites. Cocaine and codeine were the primary analytes identified in sweat patches and hair. Drugs were detected in sweat within 8 h after dosing, and drug secretion primarily occurred within 24 h after dosing. No clear relationship was observed between dose and drug concentrations in sweat. Drug incorporation into hair appeared to be dose-dependent. Drugs were detected in hair within 1-3 days after the last drug administration; peak drug concentrations generally occurred in the following 1-2 weeks; thereafter, drug concentrations decreased. Solvent washes removed 50-55% of cocaine and codeine from hair collected 1-3 days after the last drug dose. These data may reflect removal of drug that was deposited by sweat shortly after dosing. Drug removed by washing hair collected 1-3 weeks after the last dose was minimal for cocaine but variable for codeine. Drug in these specimens was likely transferred from blood to germinative hair cells followed by emergence of drug in growing hair. These findings suggest that drug deposition in hair occurs by multiple mechanisms.

Detection of nandrolone, testosterone, and their esters in rat and human hair samples

Nandrolone and testosterone are anabolic androgenic steroids occasionally abused by athletes. A sensitive, specific, and reproducible gas chromatography-mass spectrometry method for the quantitative determination of nandrolone, testosterone, and their esters in hair has been developed. The limits of quantitation of this method, based on 20 mg of hair, were 50 pg/mg for nandrolone and testosterone, 100 pg/mg for testosterone acetate, and 200 pg/mg for nandrolone-decanoate. Nandrolone-d3 and testosterone-d3 were used as internal standards. This method has been applied to the analysis of these compounds incorporated into rat and human hair. Male Long-Evans rats were given nandrolone decanoate 60 mg/kg intraperitoneally (i.p.) once daily for 10 days over a time period of 14 days. Two of the three rats contained nandrolone in the pigmented hair collected at day 21 at a concentration of 63 and 76 pg/mg, respectively. No drug was found in the corresponding nonpigmented hair. The rat hair samples that tested positive for nandrolone contained also nandrolone decanoate in concentrations of 0.9 and 1.2 ng/mg, respectively. In a separate experiment rats were given testosterone acetate 10 mg/kg i.p. once daily for five days. No testosterone or testosterone acetate was detected in the rat hair samples. Hair specimens were also obtained from four self-reported steroid users. The hair of two subjects were determined to be positive for testosterone in concentrations of 54 and 81 pg/mg. These data demonstrate that it is possible to detect the steroids nandrolone, testosterone, and nandrolone decanoate in hair after systemic administration.

Simultaneous quantitation of cocaine, opiates, and their metabolites in human hair by positive ion chemical ionization gas chromatography-mass spectrometry

A sensitive method is developed for the combined extraction of cocaine (COC), cocaethylene (CE), benzoylecgonine (BE), ecgonine methyl ester (EME), norcocaine (NORCOC), 6-acetylmorphine (6-MAM), codeine (COD), norcodeine (NORCOD), morphine (MOR), and normorphine (NORMOR) from human head hair using an enzyme-based digestion technique (Protease VIII/DTT/Tris-buffer pH 6.5 at 22 degrees C). After pH adjustment to 5.5, the digests are extracted with a solid-phase extraction procedure using Bond-Elut Certify columns. The extract residues are evaporated at 40 degrees C, reconstituted in 20 microL of ethyl acetate, and derivatized with the reagents N-methyl-N-trimethylsilylheptafluorobutyramide (MSHFBA), N-methyl-bis-heptafluorobutyramide (MBHFBA), and N-trimethylsilylimidazole (TMSIM). Analyses are performed by positive ion chemical ionization gas chromatography-mass spectrometry using a DB-1 capillary column. Two injections are performed on each extract to optimize sensitivity for all analytes. The assay is capable of reliably quantitating 500 pg/mg of all compounds and is linear to 50 ng/mg, except for BE, which is linear to 25.0 ng/mg. The method was used to analyze human hair samples obtained from cocaine and heroin users. COC, BE, and EME are detectable in all samples, whereas NORCOC, CE, COD, 6-MAM, and MOR are detected in only some samples. Norcodeine and normorphine are not detected. The assay is currently being used to analyze hair samples from a study investigating the mechanisms of drug disposition in hair.

Drug testing with alternative matrices I. Pharmacological effects and disposition of cocaine and codeine in plasma, sebum, and stratum corneum

This study examined the disposition of cocaine, codeine, and metabolites in stratum corneum, sebum, and plasma collected from five African-American males after administrations of cocaine and codeine during a 10-week inpatient clinical study. The subjects were experienced, healthy drug users with a recent history of cocaine and heroin abuse. The first drug administration was delayed by three weeks to allow for the elimination of previously administered drugs from the body. Subjects received three 75 mg cocaine hydrochloride/70 kg doses by the subcutaneous route and three 60 mg codeine sulfate/70 kg doses by the oral route on alternating days beginning in week 4. The same dosing sequence was repeated in week 8 with doubled (x 2) doses. Pharmacological measures (heart rate, pupil diameter, subject "High" and "Liking") were obtained simultaneously with blood. Stratum corneum was collected by scraping regions of the back once each week. Sebum was collected periodically from the forehead by applying Sebutape patches for 1-2-h intervals. Plasma, stratum corneum, and sebum were analyzed for cocaine, codeine, and metabolites by gas chromatography-mass spectrometry. Peak plasma cocaine concentrations occurred within the 30 min following dosing and followed peak pharmacological effects. Peak plasma codeine concentrations occurred within 1-2 h of dosing and before peak pharmacological effects. Cocaine and codeine were the primary analytes in sebum and stratum corneum. After dosing, these drugs appeared in sebum within 1-2 h and were detected for 1-2 days. Peak-drug concentrations in stratum corneum occurred one day after completion of dosing; elimination of the drugs continued over the next 1-2 weeks after dosing. Overall, no definitive relationship was observed between drug concentrations in sebum and stratum corneum compared with dose. Interpretation of drug distribution and elimination in sebum and stratum corneum was complicated by possible contamination of specimens with drugs from sweat. The mechanism(s) for deposition of cocaine and codeine in sebum and stratum corneum appeared to be complex and could involve the transfer of drugs between different body fluids (i.e., sebum and sweat) and other matrices (i.e., skin and hair).

In vitro characterization of cocaine binding sites in human hair

In vitro studies were performed to characterize [3H]cocaine binding to dark and light ethnic hair types. In vitro binding to hair was selective, was reversible and increased linearly with increasing hair concentration. Scatchard analyses revealed high-affinity (6-112 nM) and low-affinity (906-4433 nM) binding in hair. Competition studies demonstrated that the potencies of 3beta-(4-bromophenyl)tropane-2beta-carboxylic acid methyl ester, and 5-(4-chlorophenyl)-2,5-dihydro-3H-imidazol[2,1-alpha]isoindole-5-ol and 2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane were similar to or less than that of (-)-cocaine. The potency of (-)-cocaine was 10-fold greater than that of (+)-cocaine at inhibiting radioligand specific binding to hair. Multivariate analysis indicated that significantly greater nonspecific and specific radioligand binding occurred in dark hair than in light hair. Multivariate analysis also demonstrated a significant ethnicity x sex effect on specific and nonspecific binding to hair. Greater radioligand binding occurred in male Africoid hair than in female Africoid hair and in all Caucasoid hair types. Melanin was considered the most likely binding site for cocaine in hair. Typically, the concentration of melanin is much greater in dark than in light hair. Scatchard analysis indicated that dark hair had a 5- to 43-fold greater binding capacity than light hair. Differences in radioligand binding between hair types appeared to be due to differences in the density of binding sites formed by melanin in hair.

In vitro binding studies of drugs to hair: influence of melanin and lipids on cocaine binding to Caucasoid and Africoid hair

Although the mechanism(s) of drug deposition in hair are unknown, there is evidence that suggests that the amount and type of melanin present are major factors in determining how much drug enters hair after exposure. The role of other hair components, such as lipids, has received less attention. We used in vitro binding techniques to evaluate the binding of radiolabeled cocaine to different types of treated and untreated hair specimens. Divided male and female Caucasoid (black/brown and blond colored) and Africoid (black colored) hair specimens (N = 7) were exhaustively extracted to remove lipid components (lipid-extracted hair). Separate portions were bleached to denature or alter melanin content. Experiments with radiolabeled cocaine were performed on untreated, lipid-extracted, and bleached portions of hair from different groups. Cocaine binding was significantly higher (p < .01) to male Africoid hair compared with other groups. The amount of drug binding was similar among female Africoid and male and female, black/brown Caucasoid specimens. The lowest amount of binding was observed with blond, female Caucasoid specimens. Binding experiments also revealed that specific cocaine binding generally did not differ significantly between lipid-extracted hair and untreated hair, but bleaching of most hair specimens resulted in significant (p < .01) decreases in specific binding compared with untreated hair. In separate experiments with cocaine-treated hair specimens, digested samples were evaluated to determine if removal of the insoluble melanin fraction from soluble hair components provided a means of normalization of drug content and elimination of color bias. Removal of the insoluble melanin fraction was not effective in removal of significant amounts of cocaine, which indicated that the digestion process released bound cocaine into the digest solution. Overall, these experiments suggested that lipids in hair play a minor role in drug binding, whereas melanin functions as a major binding site for cocaine. Natural (ethnic) or artificial (bleaching) differences in melanin content may determine the extent of cocaine entrapment in hair after drug exposure. Further, digestion of hair samples and removal of insoluble melanin failed to be effective in removal of hair color bias.

Incorporation of codeine and metabolites into hair. Role of pigmentation

Xenobiotics circulating in the blood may become incorporated into growing hair. Melanin has affinity for many pharmacologically unrelated drugs and is responsible for the pigmentation in hair. To assess the role of pigmentation in the incorporation of drugs into hair, the distribution of codeine and its metabolites was studied in Sprague-Dawley (SD; white nonpigmented hair), Dark Agouti (DA; brown pigmented hair), and hooded Long-Evans (LE; both black pigmented and white nonpigmented hair) rats. Codeine was administered at a dose of 40 mg/kg/day i.p. for 5 days. Fourteen days after beginning the dosing protocol, hair was collected and analyzed for codeine, and its metabolite, morphine, by positive-ion chemical ionization GC/ion-trap MS. The plasma pharmacokinetics for codeine and morphine were also determined after a single 40 mg/kg injection (equivalent to first dose in 5-day dosing protocol) in all three strains of rats. Hair and plasma codeine and morphine concentrations were also determined after acid hydrolysis to evaluate the presence of glucuronide metabolites. Codeine concentrations in the hair of SD, DA, and pigmented LE hair were 0.98 +/- 0.10, 5.99 +/- 1.24, and 111.93 +/- 18.69 ng/mg hair, respectively; morphine concentrations were 0.34 +/- 0.04, 0.51 +/- 0.11, and 14.46 +/- 1.81 ng/mg hair, respectively; morphine glucuronide concentrations were 0.67 +/- 0.08, 1.04 +/- 0.37, and 13.80 +/- 3.60 ng/mg hair, respectively. Studies examining the in vitro binding of [3H] codeine and [3H]morphine to hair demonstrated both specific and nonspecific binding sites for codeine and morphine. Pigmented hair from LE rats possessed the greatest number of binding sites, white hair from SD rats contained the least, and brown hair from DA rats was intermediate. A time course study of codeine and its metabolites showed pigment-mediated differences in incorporation of codeine and metabolites within a few hours of drug administration. These data indicate that pigmented hair possesses a greater capacity to bind and incorporate codeine and its metabolites than does nonpigmented hair. Interpretation of hair concentrations of drugs should involve consideration of hair pigmentation.

Small cell neuroendocrine carcinoma of the vagina

A 65-year-old woman with a history of recurrent vaginal intraepithelial neoplasia was found to have small cell carcinoma (SCC). Exfoliative cytology was instrumental in the discovery of each episode of vaginal neoplasia. Thorough examination of the patient established the tumor as being primary to the vagina, and immunohistochemistry confirmed it to be a neuroendocrine SCC. Eleven patients with neuroendocrine SCC of the vagina have been reported previously. Morphologic characteristics and histogenesis are discussed within the context of the embryology and natural history of extrapulmonary-genital SCC. They have been classified in the amine precursor uptake and decarboxylation family of neoplasms. Originally, a neuroectodermal origin was proposed, but derivation now is thought to be from multipotential epithelial stem cells of the genital tract. Neuroendocrine SCC tends to be an aggressive neoplasm with a propensity for early spread. Long-term survival for patients with vaginal SCC has not been documented. Therapeutic decisions regarding SCC from this site have been based on information gained from the treatment of these tumors elsewhere. Combined modality therapy using initial surgery and adjuvant treatment, including systemic chemotherapy and local exposure to radiation, has produced an apparent complete response in our patient.

An unusual cause of GI bleeding in a quadriplegic: report of a case and review of the literature

The authors report a case of upper gastrointestinal hemorrhage in a quadriplegic. The cause was a Mallory-Weiss tear, a previously unrecognized problem in these patients. The incidence of bleeding in patients with spinal cord injury is as high as 25 percent in the few reported series. We feel that with the increased risk of gastrointestinal bleeding in the spinal cord patient and the accompanying significant mortality, early endoscopy is essential for accurate diagnosis since clues to the presence, etiology, and severity of the bleeding are often lacking.

Structure of bile acids associated with secretion in the rat cecum

An isolated in vivo rat cecal loop technique was utilized to determine what structure of bile acids is required to stimulate net colonic secretion of water and sodium. A dose response curve for water and sodium movement was determined for deoxycholic acid (1-6 mM) and chenodeoxycholic acid (3-6 mM). Both of these bile acids were associated with significant secretion of water and sodium at 4 mM concentration. Therefore, this concentration was used for all test bile acids studied. Test solutions included the tri- and di-substituted bile acids: cholic acid, hyocholic acid, 3 alpha, 7 beta, 12 alpha-trihydroxycholanic acid, 3 alpha, 12 alpha-dihydroxy-7-ketocholanic acid, ursodeoxycholic acid, 3 alpha-hydroxy-7-ketocholanic acid, 7 alpha, 12 alpha-dihydroxycholanic acid, and hyodeoxycholic acid. Only three bile acids, deoxycholic acid, chenodeoxycholic acid, and 7 alpha, 12 alpha-dihydroxycholanic acid were associated with net secretion of water and sodium. Cecal histology after incubation with bile acids revealed mucosal alterations in those sacs in which secretion occurred, but not where absorption was noted. These data indicate that bile acid-associated water and sodium secretion in the rat cecum requires a specific bile acid structure with a definite spatial relationship of the hydroxyl groups. Secretion occurred only with two alpha-hydroxyl groups in either the 3, 7, or 12 positions.