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J H Blom

Publications and source records attributed to J H Blom.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Epidemiology and natural course of benign prostatic hyperplasia].

Benign prostatic hyperplasia (BPH) is a frequent condition in men over 50 years of age. At autopsy the histological characteristics of BPH are seen in 80% of all men older than 80 years. Although BPH is so frequent, its precise etiology is still unknown. Each of the various sources from which epidemiological data on BPH can be obtained has its own specific problems in terms of potential errors and biases, which have to be taken into account in interpretation of the data from these sources. There are clear differences in the incidence of BPH in various races. In negroids BPH is more frequent than in Caucasians, while in Asiatic races BPH is less frequent. However, in Asiatics BPH occurs more frequently in men who have immigrated into western countries. Age and hormonal status are well known to be involved in the development of BPH. Other factors, such as marital status, socioeconomic class, smoking, diet, diabetes, hypertension, and liver cir-rhosis have been implicated, but their relation with the risk of developing BPH has never been proven. The natural history of BPH is characterized by an age-dependent increase in histological changes and an increase in prostate size. The histological changes compatible with BPH are found in men below the age of 30 with an incidence of less than 10%. During the 6th decade, 42% of prostatic specimens have histological signs of BPH and during the 8th decade of life more than 80% of prostatic specimens. The histological changes of BPH precede prostatic enlargement by roughly 1 decade. There is an initial spurt of prostate growth during the period of maturation and puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mitomycin C and aminoglutethimide in the treatment of metastatic prostatic cancer: a phase II study.

In a phase II study, 24 patients with metastatic prostatic cancer were treated with mitomycin C 15 mg/m2 i.v. every 6 weeks, combined with aminoglutethimide 250 mg twice a day. A low dose of 37.5 mg cortisone acetate was supplied daily to compensate for adrenal cortical suppression. A partial response was demonstrated in 4 of 24 evaluable patients with bi-dimensionally measurable metastases. Stable disease occurred in 8 patients over a period of more than 6 months. Within the maximum cumulative dose limit of 2 mg/kg body weight mitomycin C, toxicity was observed in 21 cases, including 2 deaths due to treatment toxicity. The poor response rate and high toxicity suggest that the addition of aminoglutethimide does not enhance the effect of mitomycin C in these patients.

Aged↗
PubMed1991

[A patient with a wide aorta and 2 wide kidney pelves: retroperitoneal fibrosis].

The case is discussed of a patient with renal insufficiency due to severe stenosis of both ureters brought about by a periaortic inflammatory process. Such periaortitis is seen in severe atherosclerosis; the condition allegedly occurs in 5 to 23% of all patients with an abdominal aortic aneurysm. The literature on this form of retroperitoneal fibrosis is reviewed.

Aged↗
PubMed1991

Changes in penile sensitivity following papaverine-induced erection in sexually functional and dysfunctional men.

To understand more clearly the role of penile sensitivity in sexual functioning, changes in penile thresholds resulting from papaverine-induced tumescence were studied in men who were either sexually functional or suffering from erectile dysfunction. Variable vibratory tactile stimulation was applied to 2 different sites, the base and tip of the underside of the penis. With standard psychophysical methodology, subjective thresholds were determined from a minimum of 5 threshold crossings. Results indicated a significant elevation in threshold after intracavernous papaverine injection, even though only partial erection was induced in most subjects. Men with erectile dysfunction had higher thresholds than control subjects but no difference in sensitivity was found between the base and tip of the penis. These findings indicate that low penile sensitivity is characteristic of some, although not all, men experiencing erectile problems and that this sensitivity is even lower during tumescence.

Adult↗
PubMed1990

Morphometrically estimated variation in nuclear size. A useful tool in grading prostatic cancer.

At present there are several grading systems for prostatic carcinoma. Most are difficult to reproduce. An objective method of grading seems to be necessary and could make comparisons between various groups of patients easier and grading more reliable. In the present study morphometrically estimated nuclear size and variation in nuclear size are matched with the survival rates of 207 patients who underwent total perineal prostatectomy for cancer. On the basis of morphometrically estimated variation in nuclear size the patients could be divided into two groups with significantly differing survival rates. In this way it was possible to split the group of patients with grade 2 carcinoma (Mostofi's grading system) into two groups of patients with significantly different survival rates. The survival rates in these two groups did not differ significantly from those in the patients with Grade 1 and Grade 3 tumors respectively. The results are discussed in the light of the recent literature on the subject. Morphometry seems to be a valuable tool in grading prostatic cancer.

Cell Nucleus↗
PubMed1990

Erection problems in medical practice: differential diagnosis with relatively simple method.

Functional sexual potency can be assumed when penile erection occurs during visual erotic stimulation, and to a lesser degree with normal nocturnal penile tumescence. Erection, increase in circumference as well as rigidity, can be measured with a simple device consisting of a calibrated felt band with a sliding collar fastened to 1 end. Subjects were 58 consecutive patients, mainly from a urology outpatient department, with erection problems and 67 healthy control men. Changes in penile circumference were measured during viewing of an erotic videotape and during sleep. Functional sexual potency, at least partially, was presumed to exist in 41 patients (71%), many of whom had a somatic pathological condition that might easily have been believed to be the cause of the erectile dysfunction. During the latter half of the study nocturnal penile tumescence also was measured. This group included 7 patients who did not respond to the visual stimuli, 5 of whom had normal nocturnal penile tumescence. We conclude that the erection meter, in conjunction with an erotic video test and nocturnal penile tumescence measurements, is a useful and simple device in the differential diagnosis of erectile difficulties in men. This is true especially when elaborate sleep laboratory facilities and neurophysiological equipment are not available.

Adult↗
PubMed1990

Prolonged treatment with the GnRH analogue buserelin does not affect alpha-subunit production by the pituitary gonadotroph.

Seven patients with metastatic prostatic cancer were treated with biodegradable implants of the GnRH analogue buserelin and six were treated with buserelin intranasally. After 4-24 weeks of treatment mean serum testosterone concentrations were significantly lower in the patients treated with implants than in those treated intranasally (0.7 vs 1.7 nmol/l respectively; P less than 0.01). Also, serum LH concentrations were significantly lower in the group treated with implants. Serum alpha-subunit concentrations were significantly higher than pretreatment values during buserelin treatment. However, the sum of the concentrations of alpha-subunit present either as free alpha-subunit or as a part of LH did not differ significantly from pre-treatment values after 8 weeks or more of buserelin treatment. During buserelin treatment serum LH concentrations measured by radioimmunoassay (RIA) were higher than those measured by immunoradiometric assay (IRMA). Cross-reactivity of alpha-subunit in the LH RIA accounted for many, but not all, of the observed discrepancies. We conclude that: (1) the principal long-term effect of prolonged buserelin administration on the pituitary gonadotroph is the suppression of LH beta production, while alpha-subunit production is not affected; (2) the serum concentrations of bioactive LH are better reflected by LH concentrations measured by IRMA than by those measured by RIA. (3) Subcutaneous application of biodegradable buserelin implants is more effective in suppressing serum LH and testosterone concentrations than intranasal buserelin application.

Buserelin↗
PubMed1990

Histological grading of prostatic carcinoma in prostatectomy specimens. Comparison of prognostic accuracy of five grading systems.

The prognostic accuracy of 5 histological grading systems (Broders, Anderson, Mostofi, Gleason and Mostofi-Schroeder) was compared. Grading was performed on 50 prostatectomy specimens by 5 pathologists. The results were averaged so as to reduce the impact of inter-observer variation. The Cox proportional hazards model was used to estimate the relationship between average grading scores and both time-to-recurrence and time-to-death by prostatic carcinoma. Age at surgery was considered to be a possible confounding factor and adjusted accordingly. The prognostic impact of the 5 grading systems (related to both recurrence and death caused by prostatic carcinoma) was judged by the likelihood ratio (LR) test score (chi 2 distributed with 1 df); for time-to-recurrence for the Mostofi-Schroeder score the LR was 6.54 and for the Gleason system it was 1.79. A stepwise procedure demonstrated that the best prognostic performance was reached with the Mostofi-Schroeder and Broders systems used together (with Mostofi-Schroeder weighted 1.5 times larger than Broders). For time-to-recurrence the median grading result was also used, giving results similar to the mean grading result. For time-to-death from prostatic carcinoma the LR test scores for all grading systems were relatively low. In this analysis the outcome of the Gleason system showed a minimum of prognostic ability, whereas the Broders and Mostofi-Schroeder systems had a reasonable predictive ability. Since the inter-observer variation of the Mostofi-Schroeder system was large, the Broders system is preferable. The restrictions and implications of this study are discussed and a brief review of the prognostic importance of grading of prostatic carcinoma is presented.

Aged↗
PubMed1990

Hearing loss and radiotelephony intelligibility in civilian airline pilots.

Airline pilots with a mild to moderate hearing loss are regularly examined in the Netherlands National Aerospace Medical Centre. If this hearing loss exceeds the national hearing standards not only a tone-audiometric test but also routine speech-audiometry is performed. The maximal discrimination of phonetically balanced monosyllable words (20 word lists) in 16 airline pilots (32 ears) with such a hearing loss varies between 65%-100%. However, none of these pilots complains of a bad speech-intelligibility in the cockpit. This may indicate that there is a poor relation between the routine speech discrimination and the speech intelligibility in the working situation. We developed a "speech-audiometric" test (RT-test) which is completely based on the aviation jargon used in radiotelephony (RT) communications. In our group of 16 pilots the maximal discrimination in the RT-test was excellent. Even for ears with a maximal discrimination of 65%-70% in the routine speech-audiometric test the maximal RT-discrimination was 99%-100%. These pilots were all very experienced (average: 14,360 flying hours). Undoubtedly, this experience is of great importance in radiotelephony-intelligibility.

Aircraft↗
PubMed1989

Natural history of benign prostatic hyperplasia (BPH).

The natural history of a disease describes its course without treatment. Description may be related to anatomy, pathology, changes on physical examination, symptoms of the disease under discussion, and the changes of all these parameters with time. Most information related to morphology and prostatic size resulted from autopsy series. Histological changes compatible with BPH may be present in the human prostate as early as age 30 years. The normal weight of an adult prostate is in the range of 15-20 g (autopsy specimens). The human prostate undergoes two kinds of growth: the first one is related to puberty, the second one to the development of BPH. The first increase of prostatic weight is clearly related to the endocrine changes occurring with puberty; the reasons for prostatic growth with the development of BPH are unknown as yet but seem to be related to endocrine factors. BPH rarely or never develops in early castrates. The scarce available information also shows that BPH is present at ages 70-80 in 50-75% of males studied. Only a fraction of those males showing benign prostatic enlargement actually become symptomatic. The natural history of the symptoms and their development in time and in relation to prostatic mass or other related factors is largely unknown. The available information on this subject is reviewed. In Europe, the symptomatology of BPH is described commonly in stages I-IV. Death resulting from BPH is usually related to severe infection in combination with obstructive uropathy of the upper urinary tract. Death is rare and is prevented by timely treatment. BPH and prostatic carcinoma frequently occur in the same prostatic specimen. Considering the different location of both entities within the gland, their different incidence, the difference in morphology of their early manifestations within the fine structure of the prostate, and other factors suggest that both disease entities have a different etiology. The incidence of BPH and prostatic carcinoma increases steadily with age. It is likely that age-related endocrine factors contribute to the pathogenesis of this disease.

Humans↗
PubMed1989

Pharmacokinetics and endocrine effects of the LHR analogue buserelin after subcutaneous implantation of a slow release preparation in prostatic cancer patients.

The pharmacokinetics and endocrine effects of the LHRH analogue buserelin [D-Ser(TBU)6-LHRH], released from biodegradable implants, were studied in 14 patients with stage C and D prostate cancer. Six patients received a subcutaneous implant of 3.3 mg buserelin monthly, and 8 patients received a subcutaneous implant of 6.6 mg buserelin every two months. Serum levels of buserelin decreased rapidly immediately after implantation. After 1-2 weeks a more gradual decline occurred, while in the two-monthly treated group a third phase of the elimination curve started after 5 weeks. Mean serum buserelin levels just before the next implantation in the two groups were not different. Urinary excretion of buserelin followed the same pattern. Serum LH levels in both groups became non-detectable 2 weeks after the first implant. This decrease of LH levels was accompanied by a suppression of serum testosterone to concentrations below 1 nmol/l (castration level). Side effects were not different from those observed with the intranasal application of buserelin. It is concluded that the subcutaneous application of buserelin is an easily administered form of treatment which has more profound and more reliable endocrine effects when compared with the intranasal administration of the drug. The greatest advantage of the new preparation is that the intervals between applications may be prolonged to at least 2 months.

Aged↗
PubMed1989

Treatment of benign prostatic hyperplasia by androgen deprivation: effects on prostate size and urodynamic parameters.

The possible effect of medical androgen deprivation in the treatment of benign prostatic hyperplasia has been studied in 12 patients. Six patients received the luteinizing hormone-releasing hormone agonist buserelin and 6 others received the antiandrogen cyproterone acetate. The treatment resulted in an average decrease in prostatic size of 29 per cent after 12 weeks as measured by ultrasonography. This decrease led to an increase in peak urinary flow rate, a reduction in residual urine volume and a decrease in daytime voiding frequency. However, it caused no decrease in urethral resistance but only an increase in the bladder contraction strength. After discontinuation of the treatment the prostates showed regrowth to the initial sizes within 6 to 36 weeks. The urodynamic changes were reversed as well. Although statistically significant, the urodynamic changes were minimal from a clinical viewpoint and did not lead to an unobstructed state after 12 weeks of treatment. For this reason the clinical indication for use of medical androgen deprivation in benign prostatic hyperplasia patients will remain limited for the time being.

Androgen Antagonists↗