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Biomedical subjects

Daniel H Williams

Publications and source records attributed to Daniel H Williams.

7 recordsLinked to original sources

Varicocele: surgical techniques in 2005.

Varicocele is the most common diagnosis in men presenting to fertility clinics. Traditional indications for correction of varicocele include scrotal pain, testicular atrophy, and infertility without other apparent causes. Adolescent varicocele correction is indicated if pain or testicular growth retardation is present. Following varicocelectomy most studies report improved semen parameters, increased serum testosterone, improvement in functional sperm defects, and the return of motile sperm in selected azoospermic men. However, conflicting data exists on pregnancy and fertility outcomes. Consistent data supporting the effectiveness of repairing subclinical varicoceles is sparse. Most authors generally agree that the primary effect of varicoceles is on testicular temperature. Varicoceles are diagnosed primarily by physical examination. Radiographic assessments are helpful when physical examination is inconclusive or when further objective documentation of a patient's condition is necessary. Several surgical approaches to varicocelectomy exist, each with its own advantages and drawbacks. We prefer the inguinal approach to varicocelectomy, except when there is a history of previous inguinal surgery. In such cases, the subinguinal technique is employed. Routine use of an operating microscope and a micro Doppler probe affords easier identification of vessels and lymphatics. Varicocele remains the most surgically treatable form of male infertility. Knowing the correct techniques of diagnosis and surgical correction ensures the best chance of successful outcomes in terms of post-operative morbidity, improved semen parameters, and pregnancy rates.

Adolescent↗

Vasectomy reversal: new techniques and role in the era of intracytoplasmic sperm injection.

The growing popularity of vasectomy as a primary form of birth control has also created an increasing demand for vasectomy reversal (VR). The advent of IVF with intracytoplasmic sperm injection after sperm retrieval has given couples an alternative to traditional VR. Although VR remains the most cost-effective and natural way to conceive after vasectomy, competing interests and market pressures have encouraged the development of this assisted reproductive technique (ART). The success of VR is dependent on several variables. The length of time since vasectomy and an individual surgeon's experience appear to be the most significant factors and are equally important. The success of this procedure is highly contingent on adherence to strict surgical principles of creating a water-tight, tension-free anastomosis, along with the appropriate decision whether to perform either a vasovasostomy or epididymovasostomy at the time of VR.

Humans↗

IVF and ICSI in male infertility: update on outcomes, risks, and costs.

Assisted reproductive technology with intracytoplasmic sperm injection (ICSI) is becoming an international panacea for couples struggling with infertility. The increasing popularity of these techniques and the data generated has given us a better understanding of the efficacy, consequences and costs of these procedures. There still remain many unanswered questions and controversies surrounding the use of IVF and ICSI. Increased experience, better refinement of these techniques and clearer indications for IVF and ICSI will inevitably minimize the risks associated with this procedure.

Female↗

Prenatal diagnosis of Beckwith-Wiedemann syndrome.

OBJECTIVES: The diagnosis of Beckwith-Wiedemann syndrome (BWS) typically is made after birth. To our knowledge, no established guidelines exist for the prenatal diagnosis of this condition. We present two new cases of prenatally diagnosed BWS and propose a diagnostic schema. METHODS: Published reports obtained from Medline searches were reviewed and combined with our cases. RESULTS: Our proposed schema of two major criteria (abdominal wall defect, macroglossia, macrosomia) or one major plus two minor criteria (nephromegaly/dysgenesis, adrenal cytomegaly, aneuploidy/abnormal loci, polyhydramnios) fits all published reports of prenatally diagnosed BWS. CONCLUSION: The prenatal diagnosis of BWS can be reliably made by applying our proposed guidelines. This schema allows for uniform fetal diagnosis of the syndrome and helps prepare for prenatal counseling and peri- and post-natal management strategies.

Adrenal Cortex↗

Role of bacteria in chronic prostatitis/chronic pelvic pain syndrome.

Throughout the past century, we have refined our understanding of prostatitis, moving from using a primarily clinical definition to considering it as a complex inflammatory condition. The inconsistency in identifying uropathogens in patients with symptoms of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has led to controversy in therapeutic management. There is compelling evidence that the normal prostate has minimal inflammation and no bacteria. Clinicians using the Meares/Stamey criteria identified uropathogens localized to the prostate in only 6% to 8% of CP/CPPS patients. This suggests that bacteria may have a role in less than 10% of men with CP/CPPS. That some patients respond to antimicrobials could suggest that eradication of bacteria reduces symptoms. However, the beneficial effect of antimicrobial drugs may not be due to their antibacterial action, but to their anti-inflammatory action. The normal prostate shows minimal inflammation, but only 50% of CP/CPPS patients exhibit prostatic leukocytosis. Prudence demands that we examine the function of the white blood cells--the cytokines produced. Several basic science advances allowed new avenues of research regarding the detection of molecular evidence of causative uropathogens. New research brings new controversy and unexpected findings, but further refines our understanding of the immune system and the CP/CPPS disease process.

Animals↗

Urorectal septum malformation sequence.

The urorectal septum malformation sequence consists of absent perineal and anal openings in association with ambiguous genitalia and urogenital, colonic, and lumbosacral anomalies. The full sequence is highly lethal, and the partial sequence, characterized by a single perineal opening draining a common cloaca, is compatible with life. Defects in mesodermal proliferation early in embryogenesis result in this rare condition. Timely urologic and surgical evaluations and reconstructions are imperative and necessary for survival. Urologists should be familiar with the mechanisms and presentations of this condition, as they may be involved in the diagnosis and management of such patients.

Abnormalities, Multiple↗