Prostatitis: Updates on diagnostic evaluation

Prostatitis accounts for almost 2 million office visits to urologists and primary care physicians. The label “prostatitis” refers to a diverse constellation of symptoms and disease processes. The diagnosis and treatment of this disorder present numerous challenges for the physician, including a lack of abnormal findings on physical examination, laboratory tests, and radiographic images. In this article, we offer a review of the current literature and recommendations for the evaluation and diagnosis of the patient presenting with prostatitis.     

青霉素配伍利多卡因后的药物动力学研究

本文报道青霉素配伍利多卡因后的药物动力学及生物利用度研究结果,证明利多卡因对青霉素的生物利用度无影响,且可促进青霉素的吸收,为良好的青霉素无痛溶媒,建议推广使用。     

Regulatory mechanisms of growth hormone secretion are sexually dimorphic.

Sexually dimorphic growth hormone (GH) secretory pattern is important in the determination of gender-specific patterns of growth and metabolism in rats. Whether GH secretion in humans is also sexually dimorphic and the neuroendocrine mechanisms governing this potential difference are not fully established. We have compared pulsatile GH secretion profiles in young men and women in the baseline state and during a continuous intravenous infusion of recombinant human insulin-like growth factor I (rhIGF-I). During the baseline study, men had large nocturnal GH pulses and relatively small pulses during the rest of the day. In contrast, women had more continuous GH secretion and more frequent GH pulses that were of more uniform size. The infusion of rhIGF-I (10 microg/kg/h) potently suppressed both spontaneous and growth hormone-releasing hormone (GHRH)-induced GH secretion in men. In women, however, rhIGF-I had less effect on pulsatile GH secretion and did not suppress the GH response to GHRH. These data demonstrate the existence of sexual dimorphism in the regulatory mechanisms involved in GH secretion in humans. The persistence of GH responses to GHRH in women suggests that negative feedback by IGF-I might be expressed, in part, through suppression of hypothalamic GHRH.     

Limited posterolateral surgical approach to the knee for excision of osteoid osteoma

An 18-year-old man suffered four years of undiagnosed knee pain until a CAT scan revealed an epiphyseal osteoid osteoma of the tibia located subchondrally, just medial to the proximal tibiofibular joint. A nidus in this location is not easily accessible, and its proximity to the joint surface raised concerns about damage to the tibial plateau. To facilitate excision of the tumor, cadaveric dissections were performed to develop a limited posterior approach to the proximal, lateral portion of the tibia. The CAT scan was used to calculate the precise dimensions of the tumor and its relation to the posterior tibial cortex and the proximal tibiofibular joint. With the use of the exposure developed in the laboratory and the calculations derived from the CAT scan, the tumor could be excised by removing a single block of bone 15 mm3. Intraoperative radiographs confirmed the presence of the nidus within the excised block of bone. This case report reaffirms the frequent difficulties and tardiness in diagnosing osteoid osteomas and the need to include these tumors in the differential diagnosis of knee pain and epiphyseal lesions. Before CAT scans were used, the working diagnoses were torn meniscus, juvenile rheumatoid arthritis, and bone hemangiomatosis.     

Biological consequences of cancer and its treatment and their relationship to current treatment planning

Advances in the treatment of childhood cancer have produced dramatic changes in survival. Unfortunately, many of the advances associated with this improvement have been accompanied by delayed sequelae induced by treatments such as surgery, radiotherapy, and chemotherapy. This article reviews published reports of treatment sequelae and examines their impact on the design of current forms of treatment. Recognition of the delayed effects of these treatment modalities has resulted in alterations in established therapies. This alteration is an ongoing process and demonstrates the concern of physicians with improving quality of life for long-term survivors of childhood cancer.     

Pharmacokinetics of fluvastatin after single and multiple doses in normal volunteers.

The pharmacokinetics of fluvastatin, a potent inhibitor of hydroxymethylglutaryl-CoA reductase and thus cholesterol synthesis, have been studied in 24 normal male volunteers who received [3H] fluvastatin in three different studies: a single-dose study using oral doses of 2 or 10 mg, an absolute bioavailability study using doses of 2 mg intravenously or 10 mg orally, and a multiple-dose study using 40 mg orally once daily for 6 days. Serial blood and plasma samples and complete urine and feces were collected and analyzed for total radioactivity as well as for intact fluvastatin. Fluvastatin was rapidly and almost completely (greater than 90%) absorbed from the gastrointestinal tract, although the estimated bioavailability from the 2- and 10-mg doses was only 19 to 29% because of extensive first-pass metabolism. Fluvastatin pharmacokinetics appeared to be linear over the 2- to 10-mg dose range, as indicated by dose-proportional blood levels of total radioactivity and the parent drug. Absorbed fluvastatin was completely metabolized before excretion, the biliary/fecal route being the major excretory pathway. The recovery of radioactivity after a single dose was virtually complete within 120 hours. The terminal half-lives of fluvastatin and total radioactivity averaged 0.5 to 1 hour and 55 to 71 hours, respectively, whereas the total body clearance of fluvastatin was 0.97 L/hour/kg. Repeated oral administration of 40-mg doses of [3H]fluvastatin resulted in no time-related change in pharmacokinetic characteristics, but this dose yielded greater than proportional increases in circulating levels of the parent drug, thus suggesting a saturable first-pass effect on fluvastatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chronic eyelid closure and its effect upon the human cone and rod electroretinogram

The human rod and cone systems have different spectral and adaptive sensitivities. Ganzfeld electroretinogram responses show that chronic eyelid closure, such as extensive symblepharon, can lead to dark-adaptation of the rods but simultaneously permit light-adaptation of the cones of the same eye. This effect is due to the red-filtering properties of the closed eyelid and the differential sensitivity of the two photoreceptor systems to the long wavelengths.     

Disposition of a silicon-containing amide, an inhibitor of acyl-CoA: cholesterol acyltransferase, in dog and rat

The pharmacokinetics of 3-(decyldimethylsilyl)-N-[2-(4-methylphenyl)-1-phenylethyl]propanamide (DMPP), an inhibitor of acyl-CoA:cholesterol acyltransferase, have been studied in the dog and the rat using 14C and 3H dual-labelled drug. In both species, gastrointestinal absorption of DMPP was slow and incomplete, amounting to approximately 20 per cent of the oral dose given in corn oil. In the rat, use of PEG-400, Tween 80, ethanol, and aqueous CMC as vehicles resulted in similar or lower absorption than corn oil. Absorbed DMPP was rapidly and extensively distributed to body tissues. Data from the rat showed highest concentrations of radioactivity in the liver and spleen, while concentrations in the adrenals and lung also markedly exceeded circulating radioactivity levels. In both dog and rat. DMPP was completely metabolized prior to excretion. The routes of biotransformation involved hydrolysis of the amide bond, oxidation of the phenyl ring, and degradation of the decyldimethylsilyl propanoyl moiety. The metabolites of DMPP were excreted slowly, predominantly in the faeces. The elimination half-life of 14C was 105 h in the dog and 83 h in the rat, while that of 3H was approximately 32 h in both species.     

Acute airway distress due to thyroid pathology

Patients with multinodular goiter or related thyroid disorders rarely have acute airway distress due to tracheal deviation or compression. However, our institution cares for a large number of patients with untreated multinodular goiters, and in the progression of this disorder, tracheal deviation and airway problems are relatively common. During the past 4 years, we have cared for 24 patients who were admitted with acute, life-threatening airway distress that required emergency intervention. Nine patients had emergency intubation, the remaining 15 had stridor on admission and underwent emergency operations. The series consists of 19 females and five males whose ages ranged from 37 to 89 years. Only four patients had malignant thyroid lesions (two papillary-follicular, two anaplastic), and two of these had multiple pulmonary metastases. Fifteen of the patients with multinodular goiters had a mediastinal extension that led to marked tracheal deviation. Three patients had recurrent multinodular goiters decades after previous surgery. Twenty-one patients underwent surgery at our institution, and all did well. Only one patient required sternotomy for thyroidectomy. Two patients required tracheostomy procedures, one because of tracheomalacia and the other because of poor pulmonary reserve. Interestingly, two patients had acute symptoms when in their third trimester of pregnancy. We have routinely used the laryngoscope (fiberoptic rigid or flexible) for preoperative and postoperative evaluation of the vocal cords and for determination of the condition of the larynx. On the basis of our experience with acute airway distress, we strongly advocate elective surgery for patients with multinodular goiter at the first sign of tracheal compression, especially if they have mediastinal extension.