Patient education: a potential marketing tool for the private physician

To keep pace with increasing competition, the private physician is encouraged to consider a patient education program as a marketing tool. Meeting the educational needs of patients is presented as an opportunity to create a trusting environment in the practice, enhance the doctor-patient relationship, and increase the active role of the patient in the health care process. A management model is proposed for successfully planning, organizing, staffing, leading, and controlling the patient education program.     

Effects of repeated ivermectin treatment in onchocerciasis

A group of 87 onchocerciasis patients from a hyperendemic area without vector control was treated with a single dose of 150 g/kg ivermectin. A second, third and fourth dose was administered 5, 12 and 17 months later to 44, 35 and 25 patients. Skin snip loads reduced substantially following each consecutive dose. However, after three doses 44% of the patients remained skin snip positive. Side-effects decreased from 32.2% requiring medical treatment at the first dose to none after the fourth dose. From this study it was concluded that a complete eradication of microfilariae in skin snips in severely infected persons living in a hyperendemic area without vector control is probably not feasible. Medical supervision for the observation of side-effects after the third dose can be limited.     

Induction of vascular haemostasis by Nd:YAG laser light in melanin-rich and melanin-free tissue

Haemostasis was effected in vessels of melanin-rich (MR: choroid) and melanin-free (MF: mesentery) rabbit tissue irradiated with a cw-Nd: YAG laser. The following parameters were employed: - pulse duration: 200 ms (MR) and 100ms (MF); focal spot diameter: 200 m (MR) and 80 m (MF); pulse energies: 100–250 mJ (MR) and 0.5-1J (MF); irradiances: 1.6–4.0kWcm^–2 (MR) and 1–2 × 10²kWcm² (MF). In melanin-rich tissue, laser energy is absorbed principally by melanin granules contained within the stromal melanocytes. The heat generated in these structures radiates into the surrounding tissue where it is dissipated. The damage thus incurred by the endothelium of blood vessels encompassed within this field triggers the haemostatic mechanism whereby blood flow is arrested. This effect is realized by the formation of an occluding plug of platelets, which is stabilized by the deposition of fibrin, particularly in capillaries, and to a lesser degree in larger vessels of the vascular lamina. In melanin-free tissue, haemoglobin serves as the primary site of energy absorption, which is thus shifted from the stroma to the vessel lumen. Irradiation of vessels in such tissue leads to thermocoagulation of plasma proteins and consequent stasis of blood flow.     

Are port films reliable for in vivo exit dose measurements?

The possibility of using conventional port films as an in vivo method for obtaining relative exit dose distribution in patients is evaluated. Kodak "Verification" films in "Localization" cassettes are positioned in the usual clinical conditions behind an homogeneous polystyrene phantom as well as behind a phantom containing air, wood and aluminium inhomogeneities. Taking beam divergency into account the densitometric profiles are projected back to the exit side of the phantom. They are compared to the profiles obtained with an ionization chamber used under full backscatter conditions. The agreement between the off-axis ratios determined with either method are mostly better than 2% and never exceed 5%. These phantom measurements are completed by a comparison between off-axis ratios determined on a port film for a head and neck patient and those obtained by diode dosimetry applied on the patient at the exit side of the beam. A similar agreement as between film and ion chamber on the phantoms is obtained. These encouraging results illustrate the possibilities of using conventional port films for in vivo dosimetry.     

Predicting genitourinary toxicity in patients receiving cisplatin-based combination chemotherapy: a cancer and leukemia group B study

Summary Assessment of renal function prior to cisplatin chemotherapy has long been based on measurement of creatinine clearance by 24-hour urine collection (CrC _meas). Estimated creatinine clearance (CrC _est) as calculated from the patient's age, weight, and serum creatinine level has been suggested as an adequate surrogate for CrC _meas, as it provides advantages of improved convenience, decreased cost, and possibly increased accuracy. We studied 847 patients receiving cisplatin-based chemotherapy on Cancer and Leukemia Group B (CALGB) protocols to determine whether the CrC _meas, CrC _est, or serum creatinine value or the age of the patient would predict the subsequent genitourinary (GU) toxicity. Both CrC _meas (P=0.001) and CrC _est (P=0.02) were predictive of subsequent grade 2+GU toxicity, with CrC _meas being a slightly better predictor. Patient age also influenced subsequent GU toxicity, with the risk increasing with age (P=0.0008). When patients were classified by age group and by CrC _meas, distinct subgroups were identified, with differences in the risk for grade 2+GU toxicity ranging from 14% to 32%. Using a logistic model to assess the probability of grade 2+GU toxicity, we found that an age of60 years (P=0.005), a CrC _meas value of <75 ml/min (P=0.004), and the risk characteristics of the individual cisplatin trial were important, whereas CrC _est was not. Furthermore, CrC _est proved to be a poor predictor of a CrC _meas value of <75 ml/min, misclassifying nearly half of the patients to a lower-risk subgroup. In summary, both CrC _meas and the patient's age independently provided predictive information concerning cisplatin GU toxicity. Our data support the continued clinical usefulness of determining the CrC _meas value prior to the administration of cisplatin-based chemotherapy to most patients.This study is supported by the following NIH grants: CA 26806, CA 33601, CA 11789, CA 31983, USAThe opinions or assertations contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense of the United States of America     

Capacity-limited renal glucuronidation of probenecid by humans A pilotVmax-finding study

Probenecid shows dose-dependent pharmacokinetics. When in one volunteer the dose is increased from 250 to 1,500 mg orally, thet _1/2 increased from 3 to 6 h. TheC _max was 14g/ml with a dosage of 250 mg, 31g/ml with 500 mg, 70g/ml with 1,000 mg and 120g/ml with 1,500 mg. Thet _max remained 1 h for all four dosages. The AUC/dose ratio increased with the dose, indicating nonlinear elimination. The total body clearance declined from 64.5 ml/min for 250 mg to 26.0 ml/min for 1,500 mg. The renal clearance of probenecid remained constant, 0.6–0.8 ml/min. Protein binding of probenecid is high (91%) and independent of the dose. The phase I metabolites show lower protein binding values (34–59%). The protein binding of probenecid glucuronidein vitro (spiked plasma) is 75%. Probenecid is metabolized by cytochrome P-450 to three phase I metabolites. Each of the metabolites accounts for less than 10% of the dose administered; the percentage recovered in the urine is independent of the dose. The main metabolite probenecid glucuronide is only present in urine and not in plasma. The renal excretion rate-time profile of probenecid glucuronide shows a plateau value of approximately 700g/min (46 mg/h) with acidic urine pH. The duration of this plateau value depends on the dose: 2 h at 500 mg, 10 h at 1,000 mg and 20 h at 1,500 mg. It is demonstrated that probenecid glucuronide must be formed in the kidney during its passage of the tubule. The plateau value in the renal excretion rate of probenecid value reflects itsV _max of formation.     

Detection of contamination with antineoplastic agents in a hospital pharmacy department

The contamination with fluorouracil, cyclophosphamide and methotrexate was studied in a hospital pharmacy department where these drugs were prepared. In the preparation room, air samples were taken before and during preparation of the drugs. Methotrexate was detected in one sample which was collected during preparation (0.3g/m³). Spot samples were taken in the vertical laminar airflow safety hood before and after preparation of the drugs and after cleaning of the hood. Contamination of the laminar airflow hood was: cyclophosphamide: 1–160 ng/cm²; fluorouracil: 10–62 ng/cm² and methotrexate: 2–633 ng/cm². Spot samples from the floor in front of and beneath the laminar airflow hood showed contamination with especially fluorouracil (48–236g/m²). The gloves used during preparation of the drugs were contaminated mainly with fluorouracil (5–980 ng/cm²). Urine samples from two workers involved in the preparation of the drugs were analysed for unmetabolized cyclophosphamide; it was not detected. Although no uptake of cyclophosphamide was established, it is shown that the methods for measurement of cyclophosphamide, fluorouracil and methotrexate in the preparation room are applicable for the control of occupational exposure to these drugs.     

Neurohypophyseal hormone receptors in the septum are implicated in social recognition in the rat

The effects on social recognition memory of (Arg(8))-vasopressin (AVP-(1-9), [pGlu(4), Cyt(6)]AVP-(4-8) and oxytocin locally administered into the rat's septum were investigated. In the behavioural paradigm used, a juvenile intruder was presented to an adult resident male rat twice for 5 min, with an inter-exposure interval of 120 min. Peptide-free residents investigated the juvenile during the second encounter as long as during the first encounter. Intraseptal injection just after the first encounter with graded doses of (Arg(8))-vasopressin, [pGlu(4),Cyt(6)]AVP-(4-8) or oxytocin caused a decrease of social investigation, as compared to placebo treatment, indicating facilitation of social recognition. The least effective dose was 100pg, 200pg and 300pg respectively. The action of vasopressin was blocked by both d(CH(2))(5)[Tyr(Me)(2)]AVP and d(CH(2))(5)[D-Ile(2)Ile(4)]AVP, V(1) and V(2) vasopressinergic receptor antagonists, but not by desGly(NH(2))(9)-d(CH(2))(5)[Tyr(Me)(2)Thr(4)]-OVT, an oxytocinergic receptor antagonist. None of the antagonists blocked the oxytocin-facilitating action on social recognition. They also did not affect social recognition when injected alone. The effects of vasopressin seem to be mediated by vasopressinergic receptors dissimilar to those found in the periphery, while the receptors involved in the action of oxytocin remain to be elucidated.     

Magnesium and obesity: influence of gender, glucose tolerance, and body fat distribution on circulating magnesium concentrations.

Obesity is characterized by a high risk for glucose intolerance and cardiovascular disease. Since magnesium deficiency or depletion have often been associated with both pathologies, is of interest to study magnesium status in severely obese subjects before any form of treatment. Negative magnesium balances have been described in overweight persons submitted to total starvation, hypocaloric diets, and obesity surgery. For this reason 80 non-diabetic obese men and 118 age-matched obese women were studied. Serum and erythrocyte magnesium concentrations were significantly higher in the male population but the mean values were not suggestive of a magnesium deficit before any form of treatment was started. Since metabolic abnormalities and cardiovascular risk are greater in patients with upper body fat distribution (UBFD) both sexes were subdivided according to "waist-to-hip" circumference ratio. No difference could be shown in the obese men but in women, UBFD subjects showed higher basal insulin levels and increased erythrocyte magnesium concentration as compared to those with classical gynoid fat distribution. A 75 g oral glucose tolerance test enabled the subjects to be subdivided into those with normal or impaired glucose tolerance (IGT). The IGT group in both sexes was older and more obese. Mean values of serum magnesium and erythrocyte magnesium were not decreased despite the more pronounced insulin resistance in the IGT group. However a significant negative correlation was found between fasting blood sugar/insulinaemia and erythrocyte magnesium, showing that this middle-aged obese population can maintain normal circulating levels of magnesium, in contrast to type II diabetics or older subjects where for other reasons (urinary losses or decreased intake) magnesium status is interfered with.     

New multiple congenital anomalies syndrome in a stillborn infant of consanguinous parents and a prediabetic pregnancy

We report on a term stillborn female infant with multiple congenital anomalies (MCA) which have not previously been reported as occurring together. The malformations include a first and second branchial arch sequence, ectopia cordis with congenital heart defect, caudal "regression" sequence with absent sacrum and hypoplastic right femur, ectrodactyly, left radial abnormality, islet cell hyperplasia, and skin lesions. The pregnancy was complicated by abdominal cramping with exercise, heavy vaginal bleeding, maternal obesity, and a normal screening glucose tolerance test at 6 months gestation. The infant was born to 20-year-old G3P1SAB2 Mexican-American parents who are first cousins. There was strong maternal family history of adult-onset diabetes. The malformations have some findings in common with those seen in infants of diabetic mothers. Structural defects similar to, but not inclusive of, those in our infant have been reported in 2 sibs born to a prediabetic mother with a first cousin marriage as well as in focal dermal hypoplasia. Parental consanguinity is suggestive of an autosomal recessive disorder. Alternatively, it may represent a combined multifactorial effect making the conceptus more sensitive to metabolic teratogens and thus placing it at increased risk for disruption of normal development.