Search PubMed⌕ Search

Biomedical subjects

D A Bloom

Publications and source records attributed to D A Bloom.

At least 37 records · Page 2Linked to original sources

Delayed presentation of posterior urethral valves: a not so benign condition.

PURPOSE: Posterior urethral valves are usually detected during infancy by prenatal sonography. Rarely they may be diagnosed during later childhood, adolescence or even adulthood. Less is known about presentation and outcome in these older patients. We reviewed our experience at 4 institutions with the late presentation of posterior urethral valves. MATERIALS AND METHODS: A 13-year retrospective review revealed the late presentation of posterior urethral valves in 47 patients 5 to 35 years old (mean age 8). Data collected included presenting symptomatology, radiographic findings and renal function. Statistical analysis determined the relationships among presenting symptoms, patient age at diagnosis and renal function. RESULTS: The most common presenting symptoms were diurnal enuresis in 60% of the cases, urinary tract infection in 40% and voiding pain in 13%. Other presenting symptoms in less than 10% of the cases included poor stream, gross hematuria and proteinuria. At diagnosis hydronephrosis and vesicoureteral reflux were present in 40 and 33% of the patients, respectively, while serum creatinine was elevated in 35% and end stage renal disease had developed in 10%. The severity of presenting signs and symptoms was significantly associated with renal impairment, while patient age at diagnosis was not. CONCLUSIONS: Posterior urethral valves is not merely a disease of infancy. Voiding cystourethrography should be considered in boys older than 5 years who have voiding complaints, especially in association with diurnal enuresis or urinary tract infection. Patients who present late with posterior urethral valves are at risk for progression to end stage renal disease.

Adolescent↗

Genitourinary surgery and Arthur Jacobs: father of urology in Glasgow.

Arthur Jacobs (1899-1974) was the father of urology in Glasgow. His extensive experience with genitourinary tuberculosis, ureterosigmoidostomy, and bladder augmentation were far ahead of his time. He became an expert in retropubic prostatectomy and was a pioneer in early imaging techniques.

History, 20th Century↗

Lower ureteral reconstruction.

Lower ureteral reconstruction is commonly performed in instances of congenital anomalies and ureteral injury. Keys to a successful outcome are an understanding of ureteral anatomy, familiarity with the principles of tissue handling, and the knowledge of various techniques of repair. This article presents some important and useful reconstructive techniques that can be considered in the management of patients with congenital anomaly or lower ureteral injury.

Female↗

Beyond the Trendelenburg position: Friedrich Trendelenburg's life and surgical contributions.

Friedrich Trendelenburg (1844-1924) was a giant figure in the formative years of modern surgical practice. His name lives on in the Trendelenburg position, a pelvis-up, head-down position that is of great use in surgical practice. That position, however, was certainly well known before Trendelenburg and the linkage of his name was by no means the greatest of Trendelenburg's achievements. Trendelenburg was a world class surgeon, innovator, and educator who made novel advances that spanned the entire range of surgical practice.

Eponyms↗

Renal transplantation in children with severe lower urinary tract dysfunction.

PURPOSE: Renal transplantation in children with end stage renal disease due to congenital urological malformations has traditionally been associated with a poor outcome compared to transplantation in those with a normal urinary tract. In addition, the optimal urological treatment for such children remains unclear. To address these issues, we retrospectively reviewed our experience with renal transplantation in this population. MATERIALS AND METHODS: Between 1986 and 1998, 12 boys and 6 girls a mean age of 8.4 years with a severe dysfunctional lower urinary tract underwent a total of 15 living related and 6 cadaveric renal transplantations. Urological anomalies included posterior urethral valves in 8 cases, urogenital sinus anomalies in 4, the prune-belly syndrome in 2, and complete bladder duplication, ureterocele, lipomeningocele and the VATER syndrome in 1 each. In 11 children (61%) bladder augmentation or continent urinary diversion was performed, 2 (11%) have an intestinal conduit and 5 (28%) have a transplant into the native bladder. RESULTS: In this group patient and overall allograft survival was 100 and 81%, respectively. These values were the same in all children who underwent renal transplantation at our center during this era. In the 17 children with a functioning transplant mean serum creatinine was 1.4 mg./dl. Technical complications occurred in 4 patients (22%), including transplant ureteral obstruction in 2 as well as intestinal conduit stomal stenosis and Mitrofanoff stomal incontinence. CONCLUSIONS: Renal transplantation may be successfully performed in children with end stage renal disease due to severe lower urinary tract dysfunction. Bladder reconstruction, which may be required in the majority of these cases, appears to be safe when performed before or after the transplant. A multidisciplinary team approach to surgery is advantageous.

Adolescent↗

Renal transplantation at the University of Michigan 1964 to 1999.

The Michigan Kidney Transplant Program has existed for 35 years. Outcomes have improved dramatically as the one-year survival of cadaver kidney grafts increased from 25% to 85-90%. Patient deaths in the first year are now uncommon. Indications for renal transplantation have been extended to infants, the elderly, diabetics and to patients with other significant health problems who would not have been candidates in the past. Chronic administration of large doses of corticosteroids is no longer necessary and the associated morbidity is largely avoided. Improvements in immunosuppression, especially the introduction of cyclosporine, account for much of this progress. With success has come increasing demand. Unfortunately, the gap between the number of available donor kidneys and the number of patients listed for a cadaver transplant continues to increase rather than diminish. Greater acceptance of volunteer donation, as has occurred in our own program, will help to reduce this shortage. If the past forecasts the future, we can anticipate extraordinary advances during the next 35 years.

Actuarial Analysis↗

Autonomic neurotoxicity of jellyfish and marine animal venoms.

Venoms and poisons of jellyfish and other marine animals can induce damage to the human nervous and circulatory systems. Clues to the pathogenesis and clinical manifestations of these lesions can be obtained from data of human envenomations and animal experimentation. Because many investigators are unaware that marine animal venoms have autonomic actions, this paper aims to elucidate the broad antagonistic or toxic effects these compounds have on the autonomic nervous system. Marine venoms can affect ion transport of particularly sodium and calcium, induce channels or pores in neural and muscular cellular membranes, alter intracellular membranes of organelles and release mediators of inflammation. The box jellyfish, particularly Chironex fleckeri, in the Indo-Pacific region, is the world's most venomous marine animal and is responsible for autonomic disorders in patients. The symptoms induced by these venoms are vasospasm, cardiac irregularities, peripheral neuropathy, aphonia, ophthalmic abnormalities and parasympathetic dysautonomia. Cases of Irukandji syndrome, caused by the jellyfish Carukia barnesi, have symptoms that mimic excessive catecholamine release. Coelenterate venoms can also target the myocardium, Purkinje fiber, A-V node or aortic ring. Actions on nerves, as well as skeletal, smooth or cardiac muscle occur. Recent studies indicate that the hepatic P-450 enzyme family may be injured by these compounds. The multiplicity of these venom activities means that a thorough understanding of the sting pathogenesis will be essential in devising effective therapies.

Animals↗

Charles B.G. de Nancrede: academic surgeon at the fin de siècle.

At the last turn of the century American surgery was in the midst of a number of paradigm shifts, involving transitions in technology, surgical practice, surgical specialization, patient care, surgical training, and medical economics. Charles B. G. de Nancrede was a leader during this formative period. A key figure in the transition from antiseptic to sterile technique in American medicine, he was also a prolific writer, a bold surgeon, and a great surgical educator. De Nancrede created one of the earliest prototypes of the modern multispecialty surgical departments. The coming turn of the century promises new transitions comparable to those of the past.

General Surgery↗

Partial purification of box jellyfish (Chironex fleckeri) nematocyst venom isolated at the beachside.

Chironex fleckeri, the northern Australian box jellyfish produces one of, if not, the most potent animal venoms. Study of the venom has been hampered by the limits of the animals' range and the venom's thermolability. Using retained lethality and native polyacrylamide gel electrophoresis (NPAGE), we show that lyophilization of autolysis isolated nematocysts is an effective method of transporting the venom. In addition, Sephadex G-200 chromatography, spin concentration, and NPAGE fail to demonstrate the presence of a 600 kDa protein to which the bulk of the lethal activity has been ascribed. Sodium dodecyl sulfate capillary electrophoresis of crude venom yields several protein bands with a molecular weight range of 30-200 kDa. Freeze-thaw studies show a loss of activity and NPAGE bands after two freeze thaw cycles.

Animals↗

Frederick C. McLellan and clinical cystometrics.

Precise analysis of lower urinary tract function was an unfulfilled dream only a century ago. By the late 19th century, water manometers and plethysmographs were utilized to measure bladder pressures. In the early 1900s, Rose developed a cystometer that was later improved by Munro. In 1938 Frederick C. McLellan, active in clinical research under Reed Nesbit at the University of Michigan, was the first to apply the earlier principles and cystometric tools to a large group of patients and created the first modern paradigm of bladder dysfunction. McLellan's work brought clinical relevance to the cystometer and thus precision to the analysis of lower urinary tract function.

Equipment Design↗

Pubic symphysis repair strength in simulated bladder exstrophy using a sheep model.

OBJECTIVES: To investigate the mechanical strength of various pubic symphysis suture material in a simulated animal model of neonatal bladder exstrophy. METHODS: Neonatal lamb pelves, which are the approximate size of neonatal human pelves, were used. Twenty-four neonatal lamb pelves were divided into four equal groups. A midline symphysotomy was made through the cartilaginous pubic symphysis in three groups and repaired using two figure-of-eight sutures (size 0) placed through the cartilaginous pubis using polypropylene, braided polyester, or polyglactin. The fourth group served as the control. The pelves were then tested to ultimate load in pure tension at a strain rate of 0.25 mm/s until failure. RESULTS: There was a highly significant difference between the intact specimens and the repaired specimens (P = 0.0008). For the repaired specimens, there was a significant difference in the ultimate load normalized by pubic height between those repaired with polypropylene and polyglactin (P = 0.025), but not for those repaired with polypropylene and braided polyester (P = 0.11) or braided polyester and polyglactin (P = 0.11). CONCLUSIONS: Braided resorbable sutures are recommended for pubic symphysis repair, because they have a lower tendency to cut out of the cartilage.

Animals↗

The pathophysiology of UPJ obstruction. Current concepts.

It took more than half of a century for urologists to recognize that hydronephrosis is not necessarily equivalent to obstruction. Keeping this important truism in mind, particularly when dealing with antenatal hydronephrosis, one must also remember that hydronephrosis is not a normal condition. It is conceivable that although the initial intrinsic stenosis or ureterovascular obstruction may not be clinically significant in terms of renal functional damage, as compensatory renal pelvic dilatation develops, secondary obstructive elements may be recruited to create an insertional anomaly and peripelvic fibrosis. The individual types of UPJ obstruction that are seen in diagnostic studies or on the operating table may represent isolated "snapshots" of evolving pathophysiologic processes. If this is true, patients with asymptomatic congenital hydronephrosis, although lacking obvious renal function loss, require long-term follow-up.

Humans↗

Comments on pediatric elimination dysfunctions: the Whorf hypothesis, the elimination interview, the guarding reflex and nocturnal enuresis.

AIMS OF STUDY: This paper addresses pediatric elimination disorders including nocturnal enuresis from the perspectives of terminology (the Whorf hypothesis), the elimination interview, and the guarding reflex. METHODS: The elimination interview and a modern model of normal voiding function, including the guarding reflex, are explained. RESULTS: The language of voiding dysfunction influences our perception of it. Nocturnal enuresis, and all other voiding dysfunctions, should be evaluated by a careful elimination interview. The guarding reflex may fit into an evolving etiologic paradigm for nocturnal enuresis. CONCLUSIONS: (1) Words and phrases of eliminology should aim for simplicity, clarity and accuracy. (2) Urologists need to perfect their eliminology skills vis-à-vis the elimination interview. (3) The role of the guarding reflex in nocturnal enuresis and all other voiding dysfunctions should be critically examined.

Arousal↗