Clinical syndromes associated with bicycle seats

Symptoms related to the bicycle seat are common among cyclists. Skin problems, such as chafing, ischial tuberosity pain, folliculitis, and ulceration are particularly common. Although rarely serious, these problems may cause significant discomfort and interfere with a cyclist's ability to ride. Numerous preventive measures have been recommended to prevent these problems, mostly related to seat position, seat construction, and bicycling pants. Little research is available, however, to support any of these recommendations. Research does indicate that use of skin creams is not effective for prevention of bicycle-related skin problems.     

Empirical Test Observations in Client-Server Systems

Formal statistical analysis of defect databases for two commercial client-server products for disparate applications - C-language parsing and geophysical modeling - tests the hypothesis that defects in the graphical client mask more important underlying defects in the computational server. It also quantifies the benefit of continued testing after delivery in terms of reduced software defect densities apparent to end users.     

How Accurately Do Engineers Predict Software Maintenance Tasks?

Research shows considerable overlap among perfective, corrective, and adaptive maintenance tasks in software development projects. A case study involving two recent products provides further empirical evidence of this distribution and sheds light on how well programmers estimate both the type of maintenance necessary and the duration with some significant surprises     

Use of solid phase extraction disks for the GC-MS analysis of acidic and neutral herbicides in drinking water

An analytical procedure was developed in which thirteen herbicides (10 acidic and 3 neutral compounds) may be extracted from drinking water samples using solid phase extraction disks and subsequently analyzed by gas chromatography-mass spectrometry. Using 8 replicate samples consisting of reagent water fortified with nanogram quantities of each herbicide, the average percent recoveries and method detection limits were determined for each analyte. The method was found to be suitable for the determination of individual herbicides in drinking water at concentrations of approximately 10 ng/L.     

Cyclosporin A in patients receiving renal allografts from cadaver donors. 1978

A psychrotrophic yeast, Rhodotorula glutinis KUJ 2731, isolated from soil, effectively produced an extracellular endo-beta-glucanase (EC 3.2.1.4). The enzyme was monomeric, and the molecular mass was about 40,000 Da. The N-terminal amino acid sequence was H-Ser-Leu-Pro- Lys-Leu-Gly-Gly-Val-Asp-Leu-Ala-Gly-Leu-Asp-Ile-Gly-Lys-Asp-Lys-Asn-. alpha-Helix content was calculated to be about 32.6%. The isoelectric point was 8.57. The activation energy was 20.9 kJ/mol, which was much smaller than that of mesophilic enzymes. The enzyme was active at temperatures from 0 to 70 degrees C, with a highest initial velocity at 50 degrees C similar to other psychrotrophic enzymes. The enzyme was inhibited by Hg2+. The enzyme catalyzed hydrolysis of carboxymethyl cellulose with an apparent K(m) of 1.1% and Vmax of 556 mumol/min/mg. Products from the enzymatic hydrolysis of carboxymethyl cellulose by the enzyme were glucose, cellobiose, and cellotriose. The enzyme also catalyzed the transglycosylation of p-nitrophenyl-beta-cellotrioside to cellotetraose.     

Growth kinetics and treatment response of the intracerebral rat 9L brain tumor model: a quantitative in vivo study using magnetic resonance imaging

We report the use of magnetic resonance imaging (MRI) for in situ tumor growth rate studies of experimental intracranial 9L tumors. T2-weighted spin-echo coronal magnetic resonance images of rat brains with 9L tumors were obtained every 2 days beginning at 8-11 days postimplantation using a 7 tesla MRI system. Tumors were clearly delineated in the images as a hyperintense region with a relatively well-demarcated border and minimal peritumoral edema. Tumor volumes from individual slices were summed together to yield the total tumor volume. The accuracy of this methodology for volumetric determination was verified by MRI phantom studies. Tumor growth rates determined from sequential MRI measurements of tumor volumes were quantitated in terms of volumetric doubling time. Tumor doubling times were found to range from 50 to 81 h, with an average of 66 +/- 8 h (n = 10). Intracranial 9L tumors were found to grow exponentially over the entire life span of the animal, allowing treated animals to serve as their own controls since the volumetric doubling time could be determined from three to four MRI scans before treatment administration. The intracerebral tumor growth delay following a single injection of 1, 3-bis(2-chloroethyl)-1-nitrosourea (13.3 mg/kg i.p.) allowed for noninvasive determination of in vivo log cell kill. A 2.0 +/- 0.2 (n = 3) log cell kill from 1,3-bis(2-chloroethyl)-1-nitrosourea treatment was found from post-treatment MRI volume measurements. These results demonstrate that MRI provides a powerful and sensitive method for assessing the growth and treatment response of intracranial 9L tumors in the rat.     

p53 tumour suppressor gene mutations in benign prostatic hyperplasia and prostate cancer

OBJECTIVE: Seminal vesicle cysts combined with ipsilateral renal agenesis represent a rare urological anomaly. We searched the literature to review the clinical presentation, diagnosis and therapeutic treatment options of this anomaly. METHODS: A pooled analysis was performed of 52 cases of seminal vesicle cysts combined with ipsilateral renal agenesis, including our own observation. The evaluation included: patient age at diagnosis, race, laterality (R/L), presence of ureteral remnant in the cyst, presenting symptoms, diagnostic examinations, treatment and outcome. RESULTS: The mean age at diagnosis was 30.2 years. The majority presented in the 2nd, 3rd and 4th decade of their lives. Only 2 patients (4%) were of African origin, all others were Caucasians. The distribution R:L was 2:1. Ureteral remnants were present in 14 patients (27%). The most common symptoms were: dysuria (37%), frequency (33%), perineal pain (29%), epididymitis (27%), pain following ejaculation (21%) and scrotal pain (13%). Infertility was found in 9 patients (17%). The cyst was palpable by digital rectal examination in 79%. All patients underwent intravenous urography, and 88% underwent cystoscopy. Other frequently performed investigations are: ultrasonography (27%), CT scanning (27%), vasovesiculography (46%) and urethrocystography (23%). The final treatment was open surgery in 74%, aspiration in 6%, transurethral deroofing of the cyst in 6% and spontaneous rupture in 4%. In 6% no treatment was given and in 4% the treatment is unknown. All patients were free of symptoms after open exploration. The success rates after transurethral deroofing and aspiration were 75 and 30% respectively. CONCLUSION: Seminal vesicle cysts combined with ipsilateral renal agenesis are a rare urological anomaly, occurring in men in the 2nd to 4th decade of their life. They present with symptoms of bladder irritation and obstruction and with pain in the perineum and scrotum. Epididymitis is frequently found. The diagnostic work-up consists of a digital rectal examination, transrectal and abdominal ultrasonography, CT scan and a cystoscopy. Open surgery and transurethral deroofing of the cyst give excellent results (100 and 75% cure respectively). Aspiration of the cyst should only be used for diagnostic purposes.