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P J Osther

Publications and source records attributed to P J Osther.

At least 19 recordsLinked to original sources
PubMed2004

Renal response to acute acid loading--an organ physiological approach.

OBJECTIVE: In previous studies of the renal response to acute NH4Cl acidosis no correlation was found between systemic acid-base status and the traditionally used quantity, renal net acid excretion (NAE). If NAE is to be considered a physiologically meaningful quantity then this is surprising, as the extracellular acid-base status would be expected to be the key physiological trigger for renal NAE. The object of this study was to investigate the renal response to acute non-carbonic acid loading using a quantitative organ physiological approach. MATERIAL AND METHODS: Five-h NH4Cl loading studies were performed in 10 healthy men using a randomized, placebo-controlled, crossover design. Arterialized capillary blood, serum and urine were collected hourly during the loading studies for the measurement of electrolytes and acid-base status. Concentrations of non-metabolizable base (NB) and acid (NA) were calculated from measured concentrations of non-metabolizable ions according to Kildeberg. RESULTS: In the steady state (placebo) the rate of renal excretion of NA (=-NB) was close to zero, indicating that the net extrarenal input of NA (endogeneous production, gastrointestinal absorption. skeletal release, etc.) was likewise about zero. An inverse correlation was found between blood pH and the rate of renal excretion of NA. Only a small amount of the acid load (approximately 8%) was excreted during the 5-h study period and this was accompanied by massive calciuria, indicating that mobilization of NB from bone contributed substantially to the current net extrarenal NA input. CONCLUSION: From a physiological point of view, NB can be regarded as the actual substrate for renal acid-base control, and measurement of renal turnover of NB may give a more precise description of renal acid-base metabolism during acid loading than previously described methods.

Acid-Base Equilibrium↗
PubMed2000

Stone risk after bladder substitution with the ileal-urethral Kock reservoir.

OBJECTIVE: The study was carried out to compare urinary biochemical and physicochemical environments in patients who had undergone bladder substitution with the ileal-urethral Kock reservoir, and who had no actual urinary infection, with those of healthy subjects. MATERIAL AND METHODS: The participants were 23 male patients who had undergone bladder substitution with the ileal-urethral Kock reservoir and 25 healthy men. All subjects had sterile urine at the time of urine collection. Concentrations of calcium, magnesium, phosphorus, creatinine, citrate, oxalate, and ammonia in 24-h urine samples were measured. Estimates of ion activity products of calcium oxalate (CaOx), calcium phosphate (CaP), brushite (Bru), and magnesium ammonium phosphate (MAP) in urine were calculated according to Tiselius. RESULTS: There was no significant difference in 24-h urinary volume between patients with a bladder substitute and the healthy controls. For most of the other measured values the results for patients differed significantly from those for controls. The most striking findings were markedly lower urinary excretion rates of citrate (p < 0.0001) and higher urine pH (p < 0.0001) in patients compared with controls. These findings were reflected in significantly higher levels of urinary supersaturation with respect to CaOx (p < 0.0001), CaP (p <0.0001), Bru (p < 0.0001) and MAP (stuvite) (p < 0.0001) in patients with a bladder substitute compared with healthy subjects. CONCLUSIONS: Hypocitraturia seems to be the main risk factor for calcium stone formation in non-infected Kock reservoir patients, and citrate supplementation appears to be the most obvious choice for stone prophylaxis in patients with intestinal urinary diversion and recurrent renal stone formation.

Adult↗
PubMed1999

Hyperoxaluria in idiopathic calcium nephrolithiasis--what are the limits?

OBJECTIVE: The object of this study was to investigate the role for measurement of 24-h renal oxalate excretion in the evaluation of idiopathic calcium stone formers. MATERIALS AND METHODS: Renal excretion rates of oxalate and creatinine were measured in 24-h urines in 46 consecutive male recurrent idiopathic calcium stone formers and 61 healthy males. Furthermore, day-to-day variation in renal oxalate excretion in 10 male recurrent stone formers and 10 healthy males were evaluated by measuring 24-h oxalate excretion on 5 different days in each individual. Concentrations of oxalate in urine were measured using an enzymatic method without ascorbate interference. RESULTS: The cumulative frequency distribution curves of 24-h renal oxalate excretion rates of stone formers and controls were congruent, and there were no statistically significant differences in oxalate excretion rates between stone formers and controls. Mean 24-h oxalate excretion (95%-confidence intervals) was 0.22 (0.18-0.25) mmol and 0.21 (0.18-0.24) mmol in stone formers and controls, respectively (p = 0.9). The day-to-day variation study did not reveal any differences in renal oxalate excretion pattern between stone formers and controls, and the presence of intermittent hyperoxaluria could not be confirmed. The oxalate excretion rates were generally low. CONCLUSION: In our region, there appear to be no differences in 24-h renal excretion rates of oxalate between male recurrent idiopathic calcium stone formers and healthy males, and the syndrome of mild hyperoxaluric calcium nephrolithiasis could not be identified in our population of idiopathic stone formers. Hence, a limit of abnormal oxalate excretion that distinguishes an idiopathic stone former from a non-stone former could not be defined in our population. Therefore, the value of routine measurement of urinary oxalate in idiopathic urolithiasis is difficult to accept, and cannot be recommended.

Case-Control Studies↗
PubMed1999

Metabolic evaluation and medical management of upper urinary tract stone disease. Guidelines from the Scandinavian Cooperative Group for Urinary Stones.

A set of simple guidelines for metabolic evaluation and medical/dietary management of patients with urolithiasis is presented. The evaluation scheme is based on the documented risk factors in the Nordic area and the results of controlled clinical trials, and takes its basis in the severity of the stone disease in the individual stone patient. The initial evaluation in all patients aims at diagnosing conditions with a definitive metabolic, infectious or anatomical/functional cause of stone formation (MIAF urolithiasis). Patients with MIAF urolithiasis are treated according to the nature of the underlying disease. Having excluded/diagnosed MIAF urolithiasis, patients with idiopathic calcium nephrolithiasis remain, and in this group, which comprises approximately 85% of the total stone population in the Scandinavian region, only those with a complicated stone disease are subjected to additional evaluation, which aims at identifying underlying pathophysiological derangements for which medical therapy has been proven to be effective in controlled clinical trials.

Dietary Proteins↗
PubMed1998

Ureteropelvic junction obstruction and ureteral strictures treated by simple high-pressure balloon dilation.

The long-term results of simple high-pressure balloon dilation in the treatment of ureteropelvic junction obstruction (UPJO) and ureteral strictures were evaluated. A total of 77 consecutive patients were treated: 40 had UPJO and 37 ureteral strictures. The etiology of the obstruction included congenital UPJO, previous stones, sequelae of endoscopic and open surgery, radiotherapy, and urinary tract reconstruction. A retrograde ureteroscopic approach was used. Evaluation included clinical and radiographic examinations and renal scintigraphy with diuretic wash-out. The procedure was repeated in 21 cases. The median follow-up was 29 months. The procedure was considered successful if it left the patient asymptomatic and with improved renographic function and drainage. The overall success rate was 70%. The best results were obtained in strictures secondary to stones, with a success rate of 94%, and in strictures secondary to reconstructive and ureteroscopic surgery, with a success rate of 91%. In congenital UPJO, the results were less encouraging: in patients with a symptom debut after the age of 18 years, balloon dilation was successful in 57% of cases; in patients with symptom debut before the age of 18 years, success was achieved in only 25% of cases. There were no major complications. It was concluded that simple high-pressure balloon dilation is a safe and reasonably effective technique for the management of most ureteral strictures and congenital UPJO with symptom debut in adult life. Balloon dilation seems to have no place in the treatment of primary congenital UPJO in children.

Adolescent↗
PubMed1997

[Polyglyconate or polyglycolic acid suture in patients with suspected impaired wound healing].

A randomized study of abdominal fascial closure using interrupted polyglyconate and polyglycolic acid sutures after laparotomy was carried out in 204 consecutive patients with suspected impaired wound healing. There were no statistically significant differences between the two sutures with regard to development of fascial disruption and incisional hernia. Wound infection demanding surgical intervention was found in 7% of patients with polyglyconate sutures and in 16% of those with polyglycolic acid sutures (p = 0.04). Monofilament polyglyconate suture does not reduce the incidence of fascial disruption and incisional hernia after laparotomy in patients with suspected impaired wound healing but the incidence of wound infection may be reduced compared with that of multifilament polyglycolic acid suture.

Aged↗
PubMed1995

Randomized comparison of polyglycolic acid and polyglyconate sutures for abdominal fascial closure after laparotomy in patients with suspected impaired wound healing.

A randomized study of abdominal fascial closure using interrupted polyglyconate and polyglycolic acid sutures after laparotomy was carried out in 204 consecutive patients with suspected impaired wound healing. There were no statistically significant differences between the two sutures with regard to the development of fascial disruption and incisional hernia. Wound infection demanding surgical intervention was found in 7 per cent of patients with polyglyconate sutures and in 16 per cent of those with polyglycolic acid sutures (P = 0.04). Monofilament polyglyconate suture does not reduce the incidence of fascial disruption and incisional hernia after laparotomy in patients with suspected impaired wound healing but the incidence of wound infection may be reduced compared with that of multifilament polyglycolic acid suture.

Abdominal Muscles↗
PubMed1995

An electron microscopic study of clinical Paget's disease of the nipple.

An ultrastructural study of the epidermis from eight patients with clinical Paget's disease of the nipple supports the epidermotropic theory. There was no evidence that the Paget's cells originated from keratinocytes. We propose the hypothesis that Paget's cells represent transformed ductal cells, from the subjacent lactiferous ducts of the nipple, which have migrated into the epidermis, either as neoplastic cells or as normal ductal cells with secondary in situ transformation in the epidermis.

Aged↗
PubMed1994

Urinary acidification and urinary excretion of calcium and citrate in women with bilateral medullary sponge kidney.

Urinary acidification ability, acid-base status and urinary excretion of calcium and citrate were evaluated in 10 women with bilateral medullary sponge kidney (MSK) and in 10 healthy women. Patients with MSK had higher fasting urine pH compared to normal controls (p < 0.01). Four patients had incomplete renal tubular acidiosis (iRTA), 3 had hypercalciuria, and 5 patients had hypocitraturia. The 24-hour urinary excretion of calcium was increased in the females with MSK (5.23 +/- 0.78 mmol) compared to the healthy females (3.49 +/- 0.29 mmol) (p < 0.02), and increased in MSK patients with iRTA (7.32 +/- 1.45 mmol) compared to patients with normal urinary acidification (3.83 +/- 0.12 mmol) (p < 0.01). The patients with iRTA had reduced levels of plasma standard bicarbonate (20.5 +/- 1.0) after fasting compared to patients with normal urinary acidification (23.8 +/- 0.8) and healthy women (22.7 +/- 0.6) (p < 0.01), and reduced levels of 24-hour urinary excretion of citrate (0.93 +/- 0.25 mmol) compared to patients with normal urinary acidification (3.58 +/- 0.51) and healthy women (2.78 +/- 0.49) (p < 0.005). A positive correlation was found between the degree of acidosis during ammonium chloride loading and urinary excretion of calcium (r = 0.71, p = 0.02), and a negative correlation between the degree of acidosis during ammonium chloride loading and urinary citrate excretion (r = 0.87, p = 0.001). The results suggest that defective urinary acidification might play an important role in the mechanism of hypercalciuria and hypocitraturia in patients with medullary sponge kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Renal Tubular↗
PubMed1993

[Citrate and kidney stones].

Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (< 1.6 mmol/24h) was found in 14 (33%) stone formers compared to 6 (12%) normal controls (p = 0.03). Citrate excretion expressed as citrate-creatinine ratio in 24 hour urine samples was significantly lower in the stone formers than in the healthy controls (p = 0.03), and significantly lower in healthy men, compared to healthy females (p = 0.006). There was a great variability in urinary citrate levels in both groups, and a considerable overlap in the urinary citrate excretion between normal subjects and stone formers. Factors other than urinary citrate excretion must therefore be of importance in the pathophysiology of calcium stone formation. Citrate-calcium ratio in urine proved to be a reliable index in discriminating stone formers from healthy subjects.

Adult↗
PubMed1993

Pathophysiology of incomplete renal tubular acidosis in recurrent renal stone formers: evidence of disturbed calcium, bone and citrate metabolism.

Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had lower plasma standard bicarbonate after fasting (P < 0.01) and lower urinary excretion of titratable acid (P < 0.05) and citrate (P < 0.01) compared with NUA patients and NC, and higher urinary excretion of ammonia (P < 0.05) compared with NC (P < 0.05). Hypercalciuria was found in 6 of 10 patients with iRTA compared with 3 of 10 with NUA, and 0 of 10 NC. The citrate/calcium ratio in urine was significantly reduced in iRTA compared with the value in NUA (P < 0.01), and in NUA compared with NC (P < 0.05). Biochemical markers of bone formation (serum osteocalcin) and bone resorption (urinary hydroxyproline) were significantly increased in iRTA compared with NUA and NC (P < 0.01), indicating increased bone turnover in stone formers with iRTA. Stone formers with iRTA thus presented with disturbed calcium, bone and citrate metabolism--the same metabolic abnormalities which characterize classic type 1 RTA. Mild non-carbonic acidosis during fasting may be a pathophysilogical factor of both nephrolithiasis and disturbed bone metabolism in stone formers with iRTA.

Acid-Base Equilibrium↗
PubMed1992

A double-blind placebo-controlled trial of omeprazole on urinary pH in healthy subjects.

Urinary pH is related to urinary calculus formation as well as urinary infection. Omeprazole is an effective inhibitor of gastric acid secretion through inhibition of the parietal cell H+K+ATPase. In this study we have evaluated a possible effect of omeprazole on urine acidification. Ten healthy male subjects took placebo and omeprazole, 40 mg o.m., for 10 days in a double-blind placebo-controlled trial. Morning fasting urinary pH was measured on day 10 of each treatment course using a pH meter. No effect of omeprazole on urinary pH could be demonstrated. It is thus unlikely that it is necessary to take omeprazole treatment into consideration in stone screening. As omeprazole did not affect urinary pH, no urological side effects related to changes in urinary pH can be expected.

Adult↗
PubMed1991

[Fetal hydronephrosis].

Antental intervention in cases where the foetus was suspected of having hydronephrosis has been the subject of intense discussion in recent years where the diagnosis was technically possible. The object of this investigation was to assess the end result in foetuses with hydronephrosis diagnosed prenatally and who were treated expectantly without intervention in utero. Fourteen consecutive cases of suspected foetal hydronephrosis are described. In four of the cases the hydronephrosis was transient without consequences for subsequent renal function. Three infants died, however, immediately after birth. All three were shown to have multiple malformations and/or chromosome anomalies. Unilateral dilatation of the upper urinary tract (seven cases) was by and large, associated with a good prognosis. Foetuses with bilateral dilatation of the upper urinary tract (seven cases) had poorer prognoses but this might also be related to other serious malformations. If this is compared with the disappointing result obtained by prenatal intervention in the form of foetal surgery or introduction of vesico-amniotic stents, very little evidence is found in favour of in utero intervention. In the great majority of cases, conservative prenatal regime is preferable.

Abnormalities, Multiple↗
PubMed1991

Metastasis to the penis. Case reports and review of the literature.

Metastasis to the penis is rare, despite rich vascularization and complex circulation. Less than 200 cases have been reported. Three new cases of penis metastasis from primary tumours in the bladder and prostate, respectively, are described. The most common symptoms are penile induration and swelling. Treatments, all of which must be considered merely palliative, consist of local tumour excision, radiation therapy, cytostatic and hormone therapy, possibly with partial or total penis amputation. The prognosis is poor, irrespective of the therapy and site of the primary tumour. More than 80% of the patients die within six months after the occurrence of penis metastasis, as a result of disseminated cancer disease.

Adenocarcinoma↗
PubMed1990

Paget's disease of the nipple. A continuing enigma.

Paget's disease of the nipple, although recognized since 1874, remains in several respects enigmatic. The two main theories of its origin are 1) epidermotropic, i.e. ductal cancer cells migrating to the epidermis of the nipple, and 2) in situ appearance of malignant keratinocytes expressing the multicentricity of breast cancer. The literature is reviewed. Clinical, histologic (including classification), histochemical and electron microscopy observations and diagnostic considerations are discussed. Diagnosis is often delayed, with adverse consequences for treatment. The nipple lesions may be accompanied by ductal carcinoma of local or more extensive in situ type, or invasive tumour. Lymph-node metastasis seems to be the most important prognostic factor. The merits of radical vs. modified radical mastectomy and local excision, with or without adjuvant radiotherapy, are considered. Major studies of breast-conserving management of Paget's disease of the nipple are in progress.

Breast Neoplasms↗
PubMed1989

Nephrogenic adenoma. Reports of two cases.

Nephrogenic adenoma is a rare lesion of the urinary tract. Two cases in the urinary bladder are described. Histologically the tumor consists of cystic and tubular structures resembling the distal part of the nephron. The etiology and pathogenesis are discussed and a new etiologic theory is presented.

Adenoma↗