SunSmart: evaluation of a pilot school-based sun protection intervention in Hispanic early adolescents.

The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban neighborhoods in Los Angeles. The analytic sample was restricted to students identifying as Hispanic or Latino (n = 777). A mixed effects linear model was used to test mean changes from pre- to posttest on students' sun protection knowledge, attitudes and behaviors. Significant improvements were observed across several cognitive outcomes related to sun protection, including knowledge of and attitudes toward sun protection and self-efficacy to wear sunscreen. However, changes in sun protective behaviors were not achieved. Although some improvements were observed, future studies should identify the factors that motivate sun protection in this population and develop tailored prevention strategies, as improving the sun safe behaviors of Hispanic youths may aid in reducing the risk of melanoma in adulthood in this population.

Pyrroline-5-carboxylate reductase in human erythrocytes.

Pyrroline-5-carboxylate reductase, which converts pyrroline-5-carboxylate to proline, has been identified in human erythrocytes. The level of pyrroline-5-carboxylate reductase activity in these cells is comparable to the activity levels of major erythrocyte enzymes. The physiologic function of the enzyme in erythrocytes cannot be related to its function in other tissues, i.e., producing proline for protein synthesis. We examined the kinetic properties of erythrocyte pyrroline-5-carboxylate reductase and compared them to the properties of the enzyme from proliferating cultured human fibroblasts. We found that the kinetic properties and regulation of the erythrocyte enzyme are distinctly different from those for human fibroblast pyrroline-5-carboxylate reductase. These characteristics are consistent with the interpretation that the function of the enzyme in human erythrocytes may be to generate oxidizing potential in the form of NADP+.

Genetic evidence for a common enzyme catalyzing the second step in the degradation of proline and hydroxyproline.

The initial step in the degradation pathways of proline and hydroxyproline is catalyzed by proline oxidase and hydroxyproline oxidase, yielding delta 1-pyrroline-5-carboxylate and delta 1-pyrroline-3-hydroxy-5-carboxylate, respectively. The second step is the oxidation of delta 1-pyrroline-5-carboxylate to glutamate and delta 1-pyrroline-3-hydroxy-5-carboxylate to gamma-hydroxy-glutamate. To determine if this second step in the degradation of proline and hydroxyproline is catalyzed by a common or by separate enzyme(s), we developed a radioisotopic assay for delta 1-pyrroline-3-hydroxy-5-carboxylate dehydrogenase activity. We then compared delta1-pyrroline-3-hydroxy-5-carboxylate dehydrogenase activity with that of delta 1-pyrroline-5-carboxylate dehydrogenase in fibroblasts and leukocytes from type II hyperprolinemia patients, heterozygotes, and controls. We found that cells from type II hyperprolinemia patients were deficient in both dehydrogenase activities. Furthermore, these activities were highly correlated over the range found in the normals, heterozygotes, and patients. We conclude from these data that a common delta 1-pyrroline-5-carboxylate dehydrogenase catalyzes the oxidation of both delta 1-pyrroline-5-carboxylate and delta 1-pyrroline-3-hydroxy-5-carboxylate, and that this activity is deficient in type II hyperprolinemia.

Lactate dehydrogenase in estrogen-responsive human breast cancer cells.

Lactate dehydrogenase activity (LDH) was measured in the MCF-7 human breast cancer cell line derived at the Michigan Cancer Foundation from a patient with metastatic breast adenocarcinoma. LDH was found in the 46,000 X g supernatant of cell lysates, but not in the culture medium. Only the fifth isozyme (LDH-5) could be demonstrated by cellulose acetate electrophoresis and relative heat inactivation studies. When endogenous steroids were removed from the medium, addition of estrogen to the growth medium for several days elevated LDH 2-fold above controls; LDH was not altered when MCF-7 cells were treated with progesterone, hydrocortisone, prolactin, insulin, or triiodothyronine. A physiological concentration (0.1 nM) of 17beta-estradiol was sufficient to produce a maximal LDH increase. There were no qualitative isozyme changes in response to estrogen. LDH activity may therefore be a useful marker protein for studying hormone action in the MCF-7 human breast cancer cell line.

Pharmacokinetics of quinidine in male patients. A population analysis.

Quinidine pharmacokinetic behaviour was evaluated in 139 adult hospitalised men receiving oral quinidine therapy. A total of 391 serum quinidine concentrations were measured by enzyme immunoassay for routine clinical purposes. The NONMEM programme was used to examine the relationship between quinidine pharmacokinetics and several potential covariates. A 1-compartment open model with first-order absorption and elimination was assumed. The mean apparent volume of distribution (Vd) was about 230L. When measured, alpha 1-acid glycoprotein (AAG) levels were not included in the analysis. Oral quinidine clearance (CL) decreased with age, severe congestive heart failure and renal disease, and increased in patients with a history of alcohol abuse. The interpatient variability in CL and the intrapatient residual variability expressed as coefficients of variation (CV) were 28 and 31%, respectively. When AAG values were incorporated into the analysis, the only important covariates of CL were the AAG measurements and the presence of renal dysfunction as indicated by a calculated creatinine clearance of less than 50 ml/min (3 L/h). The interpatient variability in CL and the residual intrapatient CVs decreased to approximately 24 and 26%, respectively. Improvement of the CL model by inclusion of measured AAG strongly suggests that quinidine elimination is dependent on the free concentration of drug in plasma and supports the use of free serum quinidine concentrations when evaluating and monitoring quinidine therapy.

Evaluation of biologic sources of variation of leukocyte counts and other hematologic quantities using very precise automated analyzers.

The authors determined mean day-to-day (daily over five days), mean week-to-week (weekly over five weeks) and mean hour-to-hour (800 h, 1100 h, 1400 h) physiologic intra-individual variation of concentration values of leukocyte cell types, platelet count, and erythrocyte values (hematocrit, hemoglobin) for a group of 20 healthy adult volunteers. Total leukocyte counts and concentration values of leukocyte cell types were determined in duplicate on the Hemalong-DTM Automated Leukocyte Differential Cell Counter to minimize analytic variation. The data sets were analyzed according to an analysis of variance model. The mean physiologic hour-to-hour and week-to-week intra-individual variations in terms of % coefficient of variation included: hemoglobin, 2.5, 2.2; hematocrit, 2.6, 2.7; platelets, 1.6, 6.6; total leukocyte count, 9.4, 15.7; neutrophils, 12.9, 26.0; lymphocytes, 10.3, 13.2; monocytes, 18.6, 19.3; eosinophils, 19.9, 26.9; basophils, 7.4, 15.0; large unstained cells, 13.7, 16.0; "high-peroxidase" cells, 32.7, 25.7. Hour-to-hour variation was partitioned into random diurnal variation, group-consistent diurnal variation, and subject-specific unique individual variation. Subject-specific diurnal variation contributed greatly and statistically significantly to total diurnal variation for many of the leukocyte cell types--especially in the case of eosinophils, where it represented more than half of total diurnal variation.

Pseudomembranous trigonitis of the bladder: hormonal aetiology.

Fourteen formalin fixed and paraffin wax embedded biopsy specimens from 10 women (age range 34-68) presenting with pseudomembranous trigonitis were studied using a combination of anti-oestrogen receptor monoclonal antibodies in an avidin-biotin immunoperoxidase technique. All epithelial areas showing vaginal metaplasia exhibited staining confined to the nucleus in the basal and parabasal layers of the squamous epithelium while no staining was encountered in adjacent trigonal transitional epithelium included in nine of the biopsy specimens. The selective expression of nuclear oestrogen receptor in trigonal epithelium affected by vaginal metaplasia in a distribution similar to that reported in vaginal epithelium by other workers lends further support to oestrogen mediated aetiology in this condition and is consistent with an embryological derivation of the trigone, distinct from that of the rest of the bladder.

Can histopathologists reliably diagnose molar pregnancy?

AIMS: To assess the degree of difficulty in diagnosing partial mole by analysing intraobserver and interobserver agreement among a group of pathologists for these diagnoses. METHODS: Fifty mixed cases of partial mole, complete mole, and non-molar pregnancy were submitted to seven histopathologists, two of whom are expert gynaecological pathologists; the other five were district general hospital consultants, one of whom works in Australia. These participants gave each slide a firm diagnosis of either partial mole, complete mole, or non-molar pregnancy. Some 12 months later, the slides were recorded and again submitted for a second diagnostic round to assess intraobserver as well as interobserver agreement. Standard histological criteria for each diagnostic category were circulated with the slides. RESULTS: kappa statistics showed that complete mole could be reliably distinguished from non-molar pregnancy, but neither non-molar pregnancy nor complete mole could be easily differentiated from partial mole. In only 35 out of 50 cases was there agreement between five or more of the seven participants. Agreement between the expert gynaecological pathologists was no better than for others in the group. Interestingly, the intraobserver agreement for each pathologist was good to excellent. CONCLUSIONS: These results imply that the reported histological criteria are either not being applied consistently or that they are lacking in practical use. An atypical growth pattern of trophoblast, rather than the polar accentuation seen in normal first trimester pregnancies, seems to be the important diagnostic histological feature for partial mole. Ploidy studies might also help with problem cases.

Microassay for prostatic androgen receptors correlated with quantitative histological assessment.

A new microassay in which cryostat sections of prostate tissue were used to provide the source of soluble androgen receptor for biochemical assay, was devised using an isoelectric focusing method, with [3H]-mibolerone as the androgenic radioligand. Adjacent cryostat sections from the same tissue block were stained for diagnostic and quantitative histological assessment. The assay was used to illustrate variations in tissue androgen receptor concentration for correlation with epithelial cell content in benign prostate hyperplasia and prostatic cancer, and to show the effects of androgen receptor concentration of resection of prostatic tissue by electroresection. The results indicate that the heat in electroresection renders prostatic tissue unsuitable for androgen receptor assays, and suggest that knowledge of the cellular composition of carcinomatous prostates may be of importance in the full assessment of androgen receptor assay results. This method incorporates both a biochemical assay and histological assessment of the assayed tissue on near-facsimile sections, an advantage over conventional biochemical assays.

Pain insensitivity in schizophrenic patients. A surgical dilemma.

Some schizophrenic patients have decreased pain perception while others have decreased pain expression. These factors frequently lead to difficulties in the diagnosis of acute intra-abdominal surgical emergencies. Increasingly large numbers of schizophrenic patients are being cared for in the community. It is therefore imperative that surgeons be acutely aware of the diagnostic dilemmas presented by this group of patients so that misdiagnosis is avoided and appropriate surgical therapy is instituted in a timely manner.

Primary lymphoma of the thyroid, the association with Hashimoto's thyroiditis.

This paper reviews the cases of thyroid lymphoma seen at one centre to assess the relationship between autoimmune thyroiditis and the subsequent development of thyroid lymphoma. Twenty two cases of thyroid lymphoma were seen over a 10 year period; 5/22 (23%) had previously been diagnosed as having Hashimoto's thyroiditis. The series comprised 18 women and four men; mean (range) age at presentation was 64 (26-85) years. All patients presented with a rapidly enlarging goitre and 13/22 (59%) underwent surgical excision prior to diagnosis of lymphoma. Nineteen of 22 (86%) patients underwent radiotherapy. The 5-year mortality for stage IE disease was 43%, survival appeared to be unrelated to previous Hashimoto's thyroiditis or to surgical resectability. The histological differentiation between pre-existing thyroiditis and thyroid lymphoma is often difficult and may lead to an underestimate in the reporting of the association. A prospective study of serial autoantibody assays in patients with Hashimoto's thyroiditis may be useful in predicting the onset of lymphomatous change in this condition.

Laparoscopic antireflux surgery.

BACKGROUND: The purpose of this paper is to review the experience of a community surgeon performing laparoscopic antireflux procedures (LAP). The experience has been difficult and at times unsettling, and underscores the need for advanced laparoscopic expertise not normally obtained performing laparoscopic cholecystectomies. METHODS: Sixty-one consecutive patients underwent attempted LAP. The preoperative evaluation is reviewed, and the length of operative times, conversion rates, complications, and patient satisfaction is discussed. RESULTS: Four patients were converted to an open procedure, and two more patients required later reoperation for dysphagia. While the operative times are shorter now, the technical difficulty in performing the procedure does not seem to be appreciatively decreasing. No deaths or esophageal perforations occurred; however, there were a large number of patients with varying degrees of troubling dysphagia that did not require reoperation but frequently required endoscopic gastroduodenoscopy (EGD) dilatation. No recurrence of reflux has been documented in the short 2-year follow-up period. CONCLUSIONS: LAP is still the most difficult procedure that I perform, and the learning curve is at least 60 cases. Patient satisfaction is quite good as only three have mild "heartburn." Dysphagia is a significant problem that has led to takedown of several short gastric vessels to obtain looser fundoplications around larger and larger bougies. Appropriate patient preoperative selection is paramount and the antireflux procedure should be tailored to the individual patient. Major complications have been reported elsewhere, but have not been seen in this review.

Thyroid and parathyroid surgical complications.

Ninety-five thyroid and 19 parathyroid patients underwent 114 operations over the past 10 years. Total thyroidectomy was the preferred procedure. There were no recognized injuries to the external branch of the superior laryngeal nerve. Five recurrent laryngeal nerve injuries occurred, but only one was clinically significant. Most injuries (three of five) occurred during lobectomies. One injury occurred during a total thyroidectomy, and one occurred during a completion thyroidectomy. No patients developed permanent hypoparathyroidism. The nerve injury rate was 1%, and the hypoparathyroidism rate was 0% for 114 operations.

Quantitative real-time monitoring of dryer effluent using fiber optic near-infrared spectroscopy.

This paper describes a method for real-time quantitation of the solvents evaporating from a dryer. The vapor stream in the vacuum line of a dryer was monitored in real time using a fiber optic-coupled acousto-optic tunable filter near-infrared (AOTF-NIR) spectrometer. A balance was placed in the dryer, and mass readings were recorded for every scan of the AOTF-NIR. A partial least-squares (PLS) calibration was subsequently built based on change in mass over change in time for solvents typically used in a chemical manufacturing plant. Controlling software for the AOTF-NIR was developed. The software collects spectra, builds the PLS calibration model, and continuously fits subsequently collected spectra to the calibration, allowing the operator to follow the mass loss of solvent from the dryer. The results indicate that solvent loss can be monitored and quantitated in real time using NIR for the optimization of drying times. These time-based mass loss values have also been used to calculate "dynamic" vapor density values for the solvents. The values calculated are in agreement with values determined from the ideal gas law and could prove valuable as tools to measure temperature or pressure indirectly.

Determination of codeine and morphine in human plasma by high performance liquid chromatography with serial electrochemical detection.

A method is described for the determination of codeine and its metabolite, morphine, at low nanogram concentrations in plasma. Analysis is accomplished by high-performance liquid chromatography utilizing a cyanopropyl normal bonded phase (NBP) column in reversed-phase mode and two electrochemical detectors in series configuration. Two internal standards are utilized, ethyl morphine for codeine and nalorphine for morphine. Codeine and morphine concentration data are presented for several patients receiving codeine-containing medications. The lower limit of detectability was 2.00 +/- 0.39 ng per mL for codeine and 1.20 +/- 0.83 ng per mL for morphine. The patient sample mean within-run coefficients of variation for codeine and morphine (at 10 ng per mL) were less than 10 percent, n = 30. The between-run coefficient of variation for codeine was also less than 10 percent (over a range of two to 190 ng per mL, n = 61), and was approximately 15 percent for morphine (over a range of two to 40 ng per mL, n = 31).

Determination of pentobarbital and certain other barbiturates by capillary gas-liquid chromatography.

A rapid capillary gas-liquid chromatographic method for the determination of barbiturates in plasma at concentrations of clinical importance is presented. This method employs a rapid and simple extraction procedure and direct flame ionization detection with no derivatization.

Determination of tricyclic antidepressants by high-performance liquid chromatography.

A method is described for the determination of amitriptyline, nortriptyline, imipramine and desipramine at low nanogram concentrations in serum. Separation and quantitation are performed by reversed-phase, isocratic, high-performance liquid chromatography utilizing ultraviolet detection at 210 nm. An internal standard, chloramitriptyline, is used as an aid to quantitation. Recovery of all four tricyclics is greater than 84%. The relative standard deviation for the analysis of amitriptyline, nortriptyline, imipramine and desipramine is less than 6% at a concentration of 100 ng/mL.

Determination of SCH 39304 by megabore capillary gas-liquid chromatography.

A gas-liquid chromatographic procedure for determination of SCH 39304 at low nanogram concentrations in serum, cerebrospinal fluid, and urine is presented. The methodology combines a high selectivity and sensitivity nitrogen-specific detector, a gas chromatograph equipped with a capillary "megabore" column, and an internal standard that is very similar in chemical structure to the drug being assayed. This method is suitable for both pharmacokinetic studies as well as for monitoring drug levels in patients receiving SCH 39304 for antifungal treatment.

Assay of free and total tocainide by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection.

A rapid high performance liquid chromatographic (HPLC) method for the determination of tocainide, using N-(2,6-dimethylphenyl)-2-amino-butanimide as an internal standard, was developed. A methylene chloride extraction involving salting out at pH 9.0 was employed. An 85:15 mixture of 0.025M monobasic potassium phosphate at pH 3.0 and acetonitrile was used as the mobile phase. The separation and quantitative analysis of tocainide was performed on a mixed phase column with a 1.0-mL/min flow rate and detection at 210 nm. Separation of tocainide from some of its metabolites required the use of heptane sulfonic acid as an ion-pairing reagent. For the free-drug assay, the specimen was centrifuged through an Amicon Centrifree filter before being processed.

Incidence of cocaine metabolites in urine specimens from medical examiners' cases.

Isobutane CIMS is useful for determining the molecular weight of morphine and its derivatives, as well as for identifying labile acyl substituents on morphine's O-6 position. Furthermore, this technique will provide information relating to the presence or absence of pi-bonding on the C-7 carbon. The spectra of morphine derivatives can be further simplified by employing ethylenediamine as a reagent gas. This approach proves useful for eliciting or confirming molecular weight information from the CI spectrum. In our laboratory extended use of ethylenediamine has been accomplished without any deleterious effect on the mass spectrometer's source or its vacuum system. The utility of isobutane and ethylenediamine CI rests with its ability to supply the analyst with structure elucidation data that may be used to complement more detailed information extractable from either EI or CE spectra. This aspect of mass spectrometry is especially useful when one is dealing with an unknown member of a particular class of organic compounds.