The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate.

BACKGROUND: The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. METHODS: Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined. RESULTS: GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively. CONCLUSION: In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP.

A mathematical model of the mechanical link between shortening of the cardiomyocytes and systolic deformation of the left ventricular myocardium.

BACKGROUND: Left ventricular myocytes are arranged in a complex three-dimensional mesh. Since all myocytes contract approximately to the same degree, mechanisms must exist to enable force transfer from each of these onto the framework as a whole, despite the transmural differences in deformation strain. This process has hitherto not been clarified in detail. OBJECTIVE: To present a geometrical model that establishes a mechanical link between the three-dimensional architecture and the function of the left ventricular myocardium. METHODS: The left ventricular equator was modeled as a cylindrical tube of deformable but incompressible material, composed of virtual cardiomyocytes with known diastolic helical and transmural angles. By imposing reference circumferential, longitudinal, and torsional strains onto the model, we created a three-dimensional deformation field to calculate passive shortening of the myocyte surrogates. We tested two diastolic architectures: 1) a simple model with longitudinal myocyte surrogates in the endo- and epicardium, and circular ones in the midwall, and 2) a more accurate architecture, with progressive helical angle distribution varying from -60° in the epicardium to 60° in the endocardium, with or without torsion and transmural cardiomyocyte angulation. RESULTS: The simple model caused great transmural unevenness in cardiomyocyte shortening; longitudinal surrogates shortened by 15% at all depths equal to the imposed longitudinal strain, whereas circular surrogates exhibited a maximum shortening of 23.0%. The accurate model exhibited a smooth transmural distribution of cardiomyocyte shortening, with a mean (range) of 17.0 (13.2-20.8)%. Torsion caused a shortening of 17.0 (15.2-18.9)% and transmural angulation caused a shortening of 15.2 (12.4-18.2)%. Combining the effects of transmural angulation and torsion caused a change of 15.2 (13.2-16.5)%. CONCLUSION: A continuous transmural distribution of the helical angle is obligatory for smooth shortening of the cardiomyocytes, but a combination of torsional and transmural angulation changes is necessary to execute systolic mural thickening whilst keeping shortening of the cardiomyocytes within its physiological range.

The effect of intravesically administered Cetiprin on bladder spasms after transurethral resection of the prostate. A double-blind randomized study.

A double-blind study of the short-term effects of intravesically administered emepronium bromide (Cetiprin) versus placebo on bladder spasms after transurethral prostatectomy was done in 40 male patients. In the Cetiprin group there was a significant decline in the need for analgesia, and significantly fewer catheter problems. The use of intravesically instilled Cetiprin is recommended only in cases of severe postoperative bladder spasms.

A conservative approach to the management of blunt renal trauma. Results of a follow-up study.

Forty patients with abnormal radiological findings after blunt renal trauma are presented. A conservative approach to treatment led to only 3 nephrectomies in patients with renal pedicle injury and to surgery in another 4 patients; in only one case was the function of the injured kidney reduced. At follow-up 1 to 5 years later, 4 patients had mild subjective symptoms but the objective findings were few and insignificant. However, since serious sequelae (e.g. hypertension) may follow renal trauma, we suggest that these patients should be seen one year after injury for clinical examination, including renography and measurement of blood pressure.

Urological septicemia. A retrospective study.

In order to investigate the clinical course and outcome of septicemia in urological patients, data were collected retrospectively from all patients admitted to a specialized urological department, in whom positive blood cultures were drawn. During a 5-year period 91 patients were registered with urosepsis corresponding to an incidence of 1.2%. In non-iatrogenic urosepsis due to ureteral obstruction women dominated over men, however, in iatrogenic disease--after investigative manoeuvres as well as after surgery--men by large dominated the material. Gram-negative bacteria were responsible for almost 75% of the septicemias and for 99% of the cases where septic shock was present. Where a urinary infection was demonstrated prior to septicemia (45%- identical bacteria were subsequently found in the blood, whether the focus had been successfully treated or not. Septic shock developed in 20 of the patients of whom 3 died. This overall mortality of 3% occurred only in patients with comcomitant serious disease. In general the course of septicemia was benign and the complication rate low. It is concluded that in urological patients septicemia is a less serious problem than in gastroenterological patients. The possible explanation for this is discussed in relation to the more discrete diagnostic and therapeutical procedures in the urological clinic.

Does the oesophageal balloon compress oesophageal varices?

The pressure transmitted to the oesophageal wall was measured in 3 patients with bleeding oesophageal varices controlled by balloon tamponade. The pressure transmitted was considerably lower than the pressure inflated, and all patients suffered retrosternal pain when the transmitted pressure rose to 40 mm Hg. Furthermore, the diameters of oesophageal balloons of 23 Sengstaken-Blakemore tubes (Rüsch) were measured at increasing inflation pressure. The compliance was very high. All balloons bulged at median inflation pressures of 75 mm Hg, and the pressures fell to a median of 55 mm Hg unaffected by further inflations. The diameter at 40 mmHg was 27.3 mm. In the light of these observations it remains still to be explained how the oesophageal balloon of the Sengstaken-Blakemore tube effects haemostasis in bleeding oesophageal varices.

Quantitative evaluation of testicular biopsies in varicocele.

Testicular biopsies from 81 patients with varicocele were evaluated by the score count method. Thirty-two patients sought treatment for infertility. Bilateral biopsies were performed in 47. Spermatogenesis was generally reduced in patients with varicocele, but there was no difference between the right and left tests. The testicular biopsy mean score correlated significantly with the total sperm count. There was no correlation between the size of the varicocele and the reduction in spermatogenesis. Although varicocele is nearly always left-sided, its mechanism of action must involve both testes. This mechanism is still unknown.

Quantitative evaluation of testicular biopsies before and after operation for varicocele.

Testicular biopsies and semen samples were examined before and approximately 1 year after operation for varicocele in 39 men. Two men were excluded because of Sertoli-cell-only syndrome. Of the remaining 37, 22 were operated upon for infertility. The testicular biopsies were quantitated with the score count method. The operation for varicocele significantly improved the testicular tissue. THe numbers of tubuli obtaining a high score increased and the biopsy mean scores also increased significantly. However, few testes became perfectly normal. The duration or the size of the varicocele apparently has little effect upon the state of the testicular tissue or the change in it after operation.

Passage of barium meal through esophagus in patients with balloon tamponade of esophageal varices.

Four patients in different states of consciousness in treatment with Sengstaken-Blakemore tube were given a barium meal. In every case the contrast medium passed the balloons and was cleared from the upper esophagus in less than four minutes, and none of it was aspirated to the bronchi.