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Biomedical subjects

W P Mali

Publications and source records attributed to W P Mali.

At least 19 recordsLinked to original sources
PubMed1992

The progression of spermatogenesis in the developing rat testis followed by 31P MR spectroscopy.

To evaluate the use of human testicular 31P MR spectroscopy as a diagnostic tool to differentiate between several stages of male infertility, we have studied the testicular levels of several phosphorus containing compounds in the rat in relation to the condition of spermatogenesis and the cell types present in the seminiferous tubules of the testis. During testicular maturation several characteristic changes occur in the 31P MR spectrum of the testis of male Wistar rats. The phosphomonoester/adenosine triphosphate (PM/ATP) ratio shows a decline from 1.61 to 1.02 between the age of 3 and 12 weeks, whereas the phosphodiester (PD)/ATP ratio increases from 0 to 0.72. The testicular pH increases in the same time from 7.06 to 7.32. Testicular MR data obtained after 12 weeks of age onward do not show significant change anymore. The high PM/ATP ratio is associated by a relative high amount of proliferating spermatogonia and spermatocytes during meiosis in the testis, whereas the PD peak seems to be correlated with the release and maintenance of spermatozoa. The MR spectra show a specific fingerprint in all developmental stages of the rat testis as a result of the different cell types in the testis.

Adenosine Triphosphate↗
PubMed1992

Renal transplant artery stenosis in children: treatment with percutaneous transluminal angioplasty.

Hypertension due to transplant renal artery stenosis was treated with percutaneous transluminal angioplasty (PTA) in 6 children. 8 angioplasties were performed and the follow-up period varied between 3 and 66 months (average 23 months). The stenoses were located at the site of anastomosis in 4 children and distal to the anastomosis in 2. PTA resulted in improvement of hypertension in all patients, although the need for antihypertensive medication remained. No grafts were lost. Our findings show that PTA of transplant renal artery stenosis in children is a good first choice of treatment.

Adolescent↗
PubMed1992

Effects of varicocele treatment in adolescents: a randomized study.

OBJECTIVE: To study the effects of varicocele treatment on testicular function in adolescents. DESIGN: A prospective controlled study in 88 randomly selected adolescents. SETTING: All participants were referred to the fertility outpatient clinic of our university hospital. PARTICIPANTS: All participants with a varicocele were randomly assigned into two groups. Group 1 (n = 33) was not treated, whereas group 2 (n = 34) was treated. A similar group of healthy volunteers without a varicocele served as a control group (group 3, n = 21). INTERVENTIONS: Testes volumes were measured at intake and during follow-up using an orchiometer. Semen analysis was performed according to standard procedures both at intake and after 1 year of follow-up. Serum hormone levels were determined at intake using a radioimmunoassay. Treatment was performed by means of transcatheter embolization of the left testicular vein. MAIN OUTCOME MEASURES: Testes volumes and semen quality at intake and after 1 year of follow-up were compared within and between the three groups. Hormonal parameters were determined at intake only. RESULTS: Before treatment, the mean left testis volume in groups 1 (n = 26) and 2 (n = 27) (20.0 mL; 95% confidence interval [CI]: 18.2 to 21.8 and 21.6 mL; 95% CI: 19.4 to 23.8, respectively) were significantly smaller than those in the control group (n = 19) (24.5 mL; 95% CI: 22.7 to 26.4). During follow-up, left testis volumes of the treated group were comparable with those in the control group (24.2 mL; 95% CI: 22.2 to 26.1 and 24.8 mL; 95% CI: 23.0 to 26.7 respectively) and significantly (P < 0.001) different from the untreated group (20.3 mL; 95% CI: 18.8 to 21.8). A significant increase in left (P < 0.01) as well as right (P < 0.05) testis volume was observed after treatment. Semen parameters before treatment were not significantly different between the three groups. Sperm concentration increased significantly (P < 0.01) from 47.4 x 10(6)/mL (95% CI: 42.5 to 53.3) to 68.9 x 10(6)/mL (95% CI: 50.6 to 87.2) in the treated group, whereas semen quality in the untreated and control groups did not change. Although both testes volumes and sperm concentration improved in the treated group, these phenomena were not consistently correlated to each other. CONCLUSIONS: Although not apparent in all adolescents, varicocele correction resulted in an increase in left testis volume and sperm concentration. At this moment, it is not clear if early preventive treatment of varicocele in adolescents, in time, will have a positive effect on testicular function.

Adolescent↗
PubMed1992

Nd:YAG laser-assisted angioplasty in femoropopliteal artery occlusions: "hot" versus "cold" recanalization with transparent contact probe.

Percutaneous recanalization of femoropopliteal artery occlusions (1-21 cm; median, 8 cm) was attempted in 50 patients. A 2.2-mm-diameter contact probe catheter connected to a continuous-wave neodymium yttrium aluminum garnet (Nd:YAG) laser was used. The laser was activated (15 W, 1-second pulses) only if too much resistance was met. Balloon angioplasty was performed after successful traversal of the occlusion. Primary success was achieved in 40 of 50 patients (80%). In 20 cases, recanalization was achieved mechanically (cold group). In the other 20 cases, recanalization was achieved with the help of laser irradiation (hot group: 15-405 J; median, 90 J). Except for the length of the obstruction (longer in the cold group), the two groups did not differ in baseline characteristics. Neither the length of the occlusion nor the duration of symptoms correlated with failure or success or with the delivered laser energy. Cold and hot groups did not differ with regard to functional improvement and angiographic patency at 3 and 12 months (94% +/- 4). Thus, brief laser activation doubled the cold primary success rate, but the major action of the laser contact probe is mechanical remodeling of the obstruction.

Adult↗
PubMed1991

[Balloon embolization of a large carotid-cavernous fistula].

A 58-year-old male patient with a giant carotid-cavernous fistula was treated by means of endovascular balloon embolisation. The fistula was closed, and good antegrade flow in the carotid artery and intracranial vessels was obtained. Based on this case history, the pathophysiology, ultrasonographic and angiographic evaluation and treatment options are reviewed.

Angiography, Digital Subtraction↗
PubMed1991

31P-NMR determination of phosphomonoesters in relation to phospholipid biosynthesis in testis of the rat at different ages.

Changes in the phosphomonoester (PM) peak, as observed in in vivo 31P-NMR spectra, are often attributed to changes in phospholipid synthesis and therefore to changes in cell proliferation. However, this technique provides information about the absolute size of the phosphomonoester pool rather than its turnover rate. To investigate whether there is a good correlation between changes in PM concentration and its turnover rate, we studied the turnover rate of the two major PM compounds, phosphocholine and phosphoethanolamine, in rat testes at different stages of testis development. [3H]Choline and [3H]ethanolamine were injected intraperitoneally into rats at the age of 3, 6 and 13 weeks, respectively. Phosphorylation of these compounds and their incorporation into phospholipids, were followed up to 6 h after injection of the phospholipid precursors. When these data were compared with the changes observed in the in vivo 31P-NMR PM peak, the concentration of the PM compounds appeared to correlate linearly, both with the conversion of choline into phosphocholine, as well with the rate of phospholipid synthesis, and therefore with the rate of cell proliferation. Hence, it is suggested that cell proliferation can be monitored by determining the changes in the PM peak that is observed in in vivo 31P-NMR spectra.

Aging↗
PubMed1991

Testis volumes, semen quality, and hormonal patterns in adolescents with and without a varicocele.

OBJECTIVE: To study the effects of varicocele on testicular function in adolescents. DESIGN: A prospective controlled study in 88 randomly selected adolescents. SETTING: All participants were referred to the fertility outpatient clinic of our University Hospital. PARTICIPANTS: All participants with a grade II varicocele (group 2) or a grade III varicocele (group 3) were selected at a district military medical council, whereas a similar group of healthy volunteers without a varicocele served as controls (group 3). INTERVENTIONS: Testis volumes were measured using an orchiometer. Semen analysis was performed according to standard procedures, and serum hormone levels were determined using a radioimmunoassay. MAIN OUTCOME MEASURE(S): Testis volumes, semen quality, and hormonal parameters in adolescents with and without a varicocele were compared. RESULTS: In group 1 (n = 21), the mean left testis volume (24.5 mL; 95% confidence interval [CI]: 22.8 to 26.2) was significantly (P less than 0.05) different from group 2 (n = 15) (20.9 mL: 95% CI: 18.5 to 23.4) and group 3 (n = 52) (20.7 mL; 95% CI: 19.2 to 22.2) (P less than 0.01) adolescents. In adolescents with a pronounced varicocele-associated left testicular growth failure, the total sperm number was reduced. However, sperm concentration, motility, and morphology were not altered. Luteinizing hormone, follicle-stimulating hormone, testosterone, and prolactin levels were all within the normal ranges in the three groups. CONCLUSIONS: Left testicular growth failure in adolescents with a varicocele is only associated with a decrease in total sperm number.

Adolescent↗
PubMed1991

31P magnetic resonance spectroscopy for diagnosing abnormal testicular function.

OBJECTIVE: To determine if testicular 31P magnetic resonance (MR) spectroscopy can be of additional clinical value. DESIGN: A controlled study in three selected subjects groups. SETTING: All participants were referred to the outpatient clinic of our Department of Obstetrics and Gynecology. PARTICIPANTS: Normal healthy volunteers (n = 13), oligozoospermic (n = 14), and azoospermic patients (n = 17; 6 with epididymal obstruction and 11 with severe germ cell depletion) were selected on the basis of semen analysis, hormone determinations, and, if necessary, on operative exploration. INTERVENTIONS: Magnetic resonance spectroscopy was performed on a Philips Gyroscan S15 (Philips Medical Systems, Best, the Netherlands). MAIN OUTCOME MEASURE(S): The routine clinical analyses were compared with the outcome of testicular MR spectroscopy to test the hypothesis that MR spectroscopy can be of additional value in the diagnosis of idiopathic oligozoospermic or azoospermic patients. RESULTS: The MR spectra of normal volunteers were significantly different from oligozoospermic patients (P less than 0.001), from azoospermic patients with germ cell depletion (P less than 0.001), and from azoospermic patients with an obstruction (P less than 0.05). Between the two azoospermic groups also a significant difference was found (P less than 0.001). CONCLUSIONS: These results show that MR spectroscopy is a reliable technique to monitor the testicular function.

Adenosine Triphosphate↗
PubMed1991

Characterization of the testicular cell types present in the rat by in vivo 31P magnetic resonance spectroscopy.

Testes of vitamin A-deficient Wistar rats before and after vitamin A replacement, of rats irradiated in utero, and of control rats were investigated by in vivo 31P magnetic resonance (MR) spectroscopy. The testicular phosphomonoester/ATP (PM/ATP) ratio ranged from 0.79 +/- 0.05 for testes that contained only interstitial tissue and Sertoli cells to 1.64 +/- 0.04 for testes in which spermatocytes were the most advanced cell types present. When new generations of spermatids entered the seminiferous epithelium, this ratio decreased. The testicular phosphodiester/ATP (PD/ATP) ratio amounted to 0.16 +/- 0.06 for testes in which Sertoli cells, spermatogonia, or spermatocytes were the most advanced cell type present. When new generations of spermatids entered the seminiferous epithelium, the PD/ATP ratio rapidly increased and finally reached a value of 0.71 +/- 0.06 for fully developed testes. Taken together, specific patterns of the PM/ATP ratio, the PD/ATP ratio, and pH were obtained that were correlated to the presence of spermatogonia, spermatocytes, round spermatids, and elongated spermatids or to the absence of spermatogenic cells. Hence, a good impression of the status of the seminiferous epithelium in the rat can be obtained by in vivo 31P MR spectroscopy.

Adenosine Triphosphate↗
PubMed1991

Abnormal testicular function: potential of P-31 MR spectroscopy in diagnosis.

Phosphorus-31 MR spectroscopy of the human testis was performed on healthy volunteers (n = 17) and oligospermic (n = 7) and azoospermic patients (n = 4). All patients in the latter group had the Sertoli-cell-only syndrome. Determination of the ratios of phosphomonoesters (PMs) to adenosine triphosphate (ATP), phosphodiesters (PDs) to ATP, and inorganic phosphate (Pi) to ATP made it possible to discriminate among these three groups. The testicular PM/ATP ratio was 1.71 +/- 0.03 (mean +/- standard deviation) in the healthy volunteers and dropped to 1.41 +/- 0.06 (P less than .001 in comparison with healthy volunteers) in the oligospermic patients and to 1.22 +/- 0.07 (P less than .001) in the azoospermic patients. The testicular PD/ATP ratio did show a slight increase from 0.52 +/- 0.10 in healthy volunteers to 0.68 +/- 0.09 (not significant) for oligospermic patients and to 0.83 +/- 0.10 (P less than .01) for azoospermic patients. The Pi/ATP ratio did not show significant differences between healthy volunteers (0.12 +/- 0.07) and oligospermic patients (0.23 +/- 0.08) but was elevated in the azoospermic patients (0.79 +/- 0.12) (P less than .001).

Adenosine Triphosphate↗
PubMed1990

[Diagnosis and treatment of renal artery stenosis in patients with a transplanted kidney].

Among the complications of kidney transplantation renal artery stenosis occurs in approximately 10% of patients. It may lead to progressive hypertension and loss of graft function. In this article possibilities and restrictions of new diagnostic and therapeutic methods are described on the basis of three case histories. Duplex Doppler ultrasonography is a useful diagnostic instrument for detection of renal artery stenosis in patients with kidney transplants. Because of its non-invasive character it is an attractive alternative to angiography. Treatment of these patients by percutaneous transluminal angioplasty (PTA) appears to give satisfying results than surgery more frequently. Although it is not always successful, PTA may be regarded as the treatment of choice since it also causes less stress than surgical management.

Adolescent↗
PubMed1990

In vitro 31P NMR spectroscopy of the reproductive organs of the male rat: an improved preparation method.

In vitro 31P spectroscopy can be applied to disentangle the broad resonances in in vivo 31P NMR spectra of the reproductive organs of the male rat. However, adenosinetriphosphate (ATP) and glycerophosphocholine (GPC), present in large amounts in vivo, are nearly completely absent in vitro. With a modified PCA extraction method, in which the organs were lyophilized before extraction, a large amount of ATP and GPC could be found in vitro. This new extraction method is probably not only restricted to in vitro analysis of the testis but is likely to be useful for analysis of other organs such as kidney and liver.

Animals↗
PubMed1990

Antegrade puncture of the femoral artery: morphologic study.

To determine the optimal site for antegrade puncture of the femoral artery, the authors evaluated three cadaver specimens and computed tomographic (CT) scans of 50 patients. The relationships among the common femoral artery, the femoral artery bifurcation, the center of the femoral head, and the inguinal ligament were evaluated. CT showed that the center of the femoral head was always located caudal to the level of the inguinal ligament but cranial to the bifurcation of the common femoral artery. Therefore, the femoral head seems to provide a reliable landmark for entering the common femoral artery.

Femoral Artery↗
PubMed1990

Insulinomas in MEN-I patients: early detection and treatment of insulinomas in patients with the multiple endocrine neoplasia syndrome type-I.

In the multiple endocrine neoplasia syndrome type I (MEN-I syndrome), periodic screening of patients and their close relatives may improve prognosis and life expectancy. Although there is diffuse involvement of the pancreas with microadenomatosis, insulinomas in the MEN-I syndrome usually occur as single tumours. This is illustrated here by two patients with insulinomas and the MEN-I syndrome. Preoperative localization of the tumours was achieved accurately by digital subtraction angiography combined with dynamic computerized tomography after a bolus injection of contrast medium. At present, two and three years after elective surgery both patients are asymptomatic. The early detection and treatment of insulinomas is extremely important because of the high risk of cerebral damage associated with late diagnosis. Periodic investigation of MEN-I family members can promote the early diagnosis and treatment of insulinomas, especially in young patients, whose life expectancy and quality of life may be improved.

Adolescent↗
PubMed1989

[Percutaneous recanalization of occluded upper leg arteries using laser treatment].

Percutaneous transluminal laser recanalization was attempted in 21 patients with occluded superficial femoral arteries and 'life style limiting claudication'. Primary success was achieved in 20 (95%) of these total occlusions. In 7/21 no laser energy was required. At one month only 1 patient had claudication and the mean Doppler ankle/arm systolic pressure ratio had increased by 0.36 +/- 0.19 (p less than 0.001) at rest and 0.47 +/- 0.34 (p less than 0.001) after exercise. Complications directly attributable to the procedure were: perforation (1), peripheral embolic episodes (2), haematoma (1), transient vasospasm (2). All complications could be treated non-surgically. These preliminary data suggest that laser recanalization of relatively short occlusions of the superficial femoral artery, followed by balloon dilatation, may be accomplished with satisfactory acute and short-term results, but not without risk.

Aged↗
PubMed1989

[Results of percutaneous transluminal angioplasty in renal artery stenosis during the period 1978-1986].

UNLABELLED: Two hundred and thirteen patients with hypertension and renal artery stenosis were treated with percutaneous transluminal renal angioplasty (PTRA). The angiographic appearance was typical of atherosclerosis in 134 patients and of fibromuscular dysplasia (FMD) in 52 patients, and could not reliably be classified in one of these groups in 27. In these patients 272 renal artery stenoses were treated. In 81% of these patients the PTRA was technically successful. The antihypertensive result in this group of 210 patients was positive (cure or improvement) in 80%. The life-table results after 5 years show cure or improvement in the atherosclerotic group (n = 35) in 80.27%, in the FMD group (n = 20) in 88.83% and in the unclassified group (n = 10) in 74.27%. One patient died from a mesenteric thrombosis and one from a myocardial infarction which both occurred within a few days after PTRA. Accordingly, the mortality was less than 1%. IN CONCLUSION: PTRA appears to be a good treatment of renovascular hypertension caused by atherosclerosis or FMD, with good long-term antihypertensive effects.

Angioplasty, Balloon↗