Urinary creatinine excretion and lean body mass

In a group of 34 adult and child subjects a high correlation (r = 0.988) was found between lean body mass, as determined by potassium-40 counting, and urinary creatinine excretion. The effect of technical errors was reduced by averaging the results of two or three 40K assays on each subject, and by making consecutive 3-day collections of urine. It appears that one can make a reasonable estimate of lean body mass from urinary creatinine excretion.     

Cyclosporin does not inhibit the tubular secretion of creatinine

BACKGROUND: The immunosuppressive drug cyclosporin is known to impair renal function. The degree of renal dysfunction is usually estimated from the clearance of creatinine (CCr). Theoretically however, a fall in CCr can be caused by a decrease of GFR, an inhibition of the tubular secretion of creatinine, or the combination of both. CsA has convincingly been shown to decrease GFR, but detailed information on the effects of CsA on tubular secretion of creatinine is lacking. METHODS: We performed two studies to investigate the influence of CsA on tubular creatinine secretion. In study A we simultaneously measured CCr and GFR (using inulin) immediately before and 4 weeks after cessation of CsA therapy in 17 renal transplant patients. In study B, the rise in serum creatinine after administration of cimetidine, which blocks the tubular secretion of creatinine, was compared in renal transplant patients treated with either CsA (in whom secretion might already be inhibited) or azathioprine. RESULTS: Study A: After cessation of CsA there was an increase of GFR (54+/-15 vs 63+/-16 ml/min/1.73 m2, PCr (71+/-21 vs 82+/-23 ml/min/1.73 m2; PCr and GFR (a measure of the relative contribution of tubular secretion to the clearance of creatinine) did not change significantly (1.33+/-0.21 vs 1. 32+/-0.30). Study B: In nine couples of patients matched for GFR the relative rises in serum creatinine after administration of cimetidine were 26+/-21% and 22+/-7% for CsA and azathioprine treated patients respectively (NS). CONCLUSION: CsA does not substantially inhibit the tubular secretion of creatinine. A rise in serum creatinine after administration of CsA can thus be attributed completely to a fall in GFR.     

Urinary calcium excretion. (Normal values for urinary calcium/creatinine ratio in Hungary). Multicenter study

Metabolic bone disorders have attracted increasing attention in Hungary due to their significant impact on public health care. Measuring urinary calcium excretion is the first step in the biochemical assessment of bone metabolism. Fasting urinary calcium corrected by creatinine excretion is widely used all over the world. The aim of the present study was to establish standard methods and normal values for the calcium/creatinine ratio in Hungary. Twenty-four centers specializing in metabolic bone diseases participated in the study. Urine standards were sent out to these centers for calcium and creatine determinations. Based on the collected data, methods were corrected in order to achieve similar results for the standards. In the second phase of the study, the normal values for calcium/creatinine ratio were determined in SI units based on the data from 1846 healthy subjects (age 20-80 yrs) including 944 females and 902 males. The normal value for females was 0.438 +/- 0.391 (means +/- SD), and 0.395 +/- 0.352 for males, respectively (p < 0.03). The ratio increased with age in both sexes. The highest values were observed between 60-64 years in women and 70-74 years in men, respectively. After this peak, the calcium/creatinine ratio decreased. The values before and after 45 years of age were significantly different both in women (0.37 +/- 0.36, vs. 0.52 +/- 0.41, p < 0.001; and men (0.32 +/- 0.23, vs. 0.47 +/- 0.45, p < 0.001). The use of this distinction is recommended in the everyday practice.     

Urinary kallikrein excretion in Bartter's syndrome

Urinary excretion of kallikrein has been studied in a patient with hypokalemic alkalosis, hyperplasia of the renal juxtaglomerular apparatus and hyperreninemia, secondary aldosteronism and resistance to the pressor effect of angiotensin II (Bartter's syndrome). Urinary kallikrein was found exceedingly high in several determination, whereas it was low in patients with essential hypertension and high in patients with primary aldosteronism. Urinary kallikrein decreased after spironolactone therapy. The rise of kallikrein excretion (which is not related to plasma renin) in this case is probably caused by a direct action of the chronic excess of plasma aldosterone; it could not be accounted for as secondary to natriuresis.     

Urinary calcium excretion in Swedish children

In order to determine whether serum anti-human T-cell lymphotropic virus type I (HTLV-I) antibody concentration is correlated with cellular viral DNA load, these 2 biological parameters were established in 22 symptomless HTLV-I carriers. The proviral copy (PVC) number was determined through quantificative polymerase chain reaction. Specific antibody titers were determined by Western blot with the end-point dilution method; the quantification of each antibody was performed through ScanBlot by determination of the peak height of each Western-blot band. A positive correlation was observed between the PVC number and the titer of total antibodies. When the association between the peak height of each antibody and the PVC number was studied, a significant positive correlation was observed only with anti-p 19. Further evaluation through follow-up studies of symptomless HTLV-I individuals is needed to clarify the value of anti-HTLV-I antibody titer as a predictor of disease progression.     

Cognition in children does not suffer from very low lead exposure

It was previously demonstrated that while lysogenic development of bacteriophage lambda in Escherichia coli proceeds normally at low temperature (20-25 degrees C), lytic development is blocked under these conditions owing to the increased stability of the phage CII protein. This effect was proposed to be responsible for the increased stimulation of the pE promoter, which interferes with expression of the replication genes, leading to inhibition of phage DNA synthesis. Here we demonstrate that the burst size of phage lambda cIb2, which is incapable of lysogenic development, increases gradually over the temperature range from 20 to 37 degrees C, while no phage progeny are observed at 20 degrees C. Contrary to previous reports, it is possible to demonstrate that pE promoter activation by CII may be more efficient at lower temperature. Using density-shift experiments, we found that phage DNA replication is completely blocked at 20 degrees C. Phage growth was also inhibited in cells overexpressing cII, which confirms that CII is responsible for inhibition of phage DNA replication. Unexpectedly, we found that replication of plasmids derived from bacteriophage lambda is neither inhibited at 20 degrees C nor in cells overexpressing cII. We propose a model to explanation the differences in replication observed between lambda phage and lambda plasmid DNA at low temperature.     

Urinary excretion of vanilmandelic acid in the glossalgia syndrome

Under observation there were 78 patients aged 41 to 70 years suffering from the glossalgia syndrome, as well as 25 clinically healthy subjects. An activation of the sympathoadrenal system was revealed in the patients. This was ascertained on the basis of the data on vanillylmandelic acid excretion with the urine. The excretion of that acid is known to be dependent on the intensity of the paraesthesias, the duration of the ailment and the character of concurrent visceral diseases. The results obtained are regarded as evidences of the participation of the vegetative nervous system in the mechanism of the glossalgia syndrome development.     

Urinary pyridinoline and deoxypyridinoline excretion in children

OBJECTIVE: There are few data on urinary markers of collagen breakdown in children. We have determined a normal range for urinary pyridinoline and deoxypyridinoline in children, assessed the variability in excretion in individual children and examined the effect of GH treatment on the excretion of these collagen cross-links. DESIGN: A cross-sectional study of a group of healthy children and sequential samples from children receiving GH treatment. PATIENTS: One hundred and nine healthy children aged 2-15 years, 8 healthy children aged 4-11 years and 4 children receiving GH treatment. MEASUREMENTS: Total pyridinoline and deoxypyridinoline excretion were measured by high performance liquid chromatography after initial acid hydrolysis and cellulose extraction steps. Serum parathyroid hormone was measured using a two-site immunoradiometric assay and urinary hydroxyproline by Ehrlich's reaction using a colorimetric assay. Pyridinoline and deoxypyridinoline excretion were expressed as a ratio against urine creatinine. RESULTS: High excretion of pyridinoline (Pyr) and deoxypyridinoline (DPyr) was seen at all ages with no apparent relation to age (mean Pyr/Cr 115 nmol/mmol and DPyr/Cr 31 nmol/mmol). No correlation was found with serum parathyroid hormone or urinary hydroxyproline excretion. Marked day to day variation was seen in individual children. A progressive rise in excretion was seen in children receiving GH treatment with no significant correlation to height velocity. CONCLUSIONS: There is a high excretion of the pyridinium cross-linking amino acids in children of all ages compared to adults. However, a high variability exists in single morning urine samples which will limit the usefulness of these markers in growing children.     

Urinary iodine excretion in the northeast of Peninsular Malaysia

A total of 2,034 subjects aged 15 years and above from different parts of the State of Kelantan were studied to determine goiter size and urinary iodine excretion. The State was divided into 2 areas - area 1 consisting of localities in the districts near the coast and area 2 consisting of localities in the inland districts. There were 1,050 subjects in area 1 and 984 subjects in areas 2. The mean age (+/- SE) of subjects in areas 1 and 2 were 38.2 + 0.5 and 37.1 +/- 0.5 years, respectively. The prevalence of goiter was 31.4% in area 1 and 45.0% in area 2; the difference was statistically significant (p < 0.05). However, the prevalence of large and visible goiters (grades II and III) was only 2.0% in area 1 and 3.3% in area 2; the difference was not statistically significant. The mean (+/- SD) urinary iodine excretion in areas 1 and 2 was 57.1 +/- 2.1 and 56.8 +/- 2.1 micrograms I/g Cr, respectively. The values were below those recommended by WHO. There was no significant difference in urinary iodine excretion between those with and without goiters in both areas and also between the grades of goiters. There were significantly more females with goiters than males in both areas but there was no significant difference in the urinary iodine excretion between the 2 sexes. Thus based on urinary iodine excretion, the iodine intake of the population in this area, was suboptimal and this was associated with a high prevalence of goiter.     

Urinary kallikrein excretion in pregnant adrenalectomized rats

The mechanisms responsible for the increase of the urinary kallikrein activity (UKA) during pregnancy is still unknown. Since aldosterone has been described as one of the stimulatory factor of UKA, and this hormone is considerably elevated in normal pregnancy it is feasible to postulate that it might be involved in the process. A preliminary approach to solve the role of the mineralocorticoid was to investigate the effect of the adrenalectomy upon UKA, of pregnant rats. UKA activity and blood pressure (BP) were measured at weekly intervals in four groups of rats: pregnant-adrenalectomized (P-ADX); pregnant-sham operated (P-C); non pregnant-adrenalectomized (NP-ADX) and non pregnant-sham operated (NP-C). In addition serum aldosterone levels in pregnant rats were determined. All the groups were maintained in similar conditions drinking 1% NaCl solution. The increase in UKA was not detected in P-C, as observed in normal pregnant rats drinking tap water, indicating that a high NaCl intake prevents the rise in UKA during gestation. However, P-C rats had higher UKA than P-ADX on day 14 of pregnancy (p < 0,05). The lowest level of UKA was found in NP-ADX. In NP-C and NP-ADX BP rose progressively throughout the experiment. BP in P-ADX rats during pregnancy and on day 7 of post partum was significantly lower than in P-C rats (p < 0,01-0,02) but in both pregnant groups it decreased significantly before parturition (p < 0,02) increasing at post-partum. Serum aldosterone levels on days 14 ans 21 of gestation, showed higher values in P-C than in P-ADX (p < 0,02-0,005). The results provide support to the assumption that adrenal gland has a regulatory action on UKA during pregnancy and that aldosterone can be one of the main factors involved.     

Urinary glycosaminoglycan excretion in NIDDM subjects: its relationship to albuminura

Nephropathy is a serious microvascular complication of diabetes mellitus which is preceded by a period of microalbuminura. Increased loss of proteoglycan (PG) from glomerular basement (GBM) has been postulated to alter glomerular charge selectivity which contributes to urinary loss of albumin. In this study we measured the excretion of urinary glycosaminoglycans (GAG), the degradation products of PG, in 82 non-insulin-dependent (NIDDM) (Type 2) diabetic and 34 non-diabetic subjects. We found that diabetic subjects had a significantly higher GAG urinary excretion rate compared to non-diabetic subjects (12.54 +/- 5.67 vs 8.80 +/- 3.99 micrograms glucuronic acid min-1, p = 0.0001). Categorizing for albuminuric status shows that the diabetic normo-, micro- and macroalbuminuric groups have a higher GAG excretion rate than non-diabetic subjects. Heparan sulphate (HS) GAG urinary excretion was measured in 25 samples from diabetic subjects and 18 non-diabetic subjects. Diabetic subjects excreted more HS GAG than controls both as a rate or as a percentage of total GAG (3.70 +/- 1.94 vs 2.38 +/- 1.48 micrograms glucosamine min-1, p = 0.02; 31.6% +/- 12.5 vs 23.1% +/- 10.4, p = 0.02). Categorizing for albuminuric status shows that micro- and macro-albuminuric groups have a significantly higher HS GAG excretion rate than non-diabetic subjects. We conclude that, as in IDDM, excretion of GAG and HS GAG is higher in NIDDM and may precede the development of microalbuminuria.     

Urinary glycosaminoglycan excretion in healthy and stone-forming children

OBJECTIVE: To investigate whether the physiological response to surgery-induced stress, as measured by changes in serum secretory proteins, is more profound on older than in younger total joint arthroplasty patients. DESIGN: Retrospective study. SETTING: A 267-bed teaching hospital. PARTICIPANTS: A total of 220 ambulatory patients with normal admission serum albumin levels, of whom 106 were 65 years of age or older (mean age 73.3 +/- 6.2 years) and 114 less than age 65 (mean age 48.8 +/- 12.2 years). METHODS: Serum albumin and transferrin levels obtained at admission an on the fifth and tenth postoperative days were compared in the two age groups. RESULTS: In both age groups, admission serum albumins were significantly higher than on the corresponding postoperative Day 5 levels (40.4 +/- 3.7 g/L vs 25.0 +/- 3.3 g/L, P < .0001 and 39.5 +/- 2.5 g/L vs 23.9 +/- 3.1 g/L, P < .001 in older and younger patients, respectively). The drop in the serum concentration of albumin by postoperative Day 5 in the older patients was not significantly different from that of the younger patients (a drop of 15.6 +/- 3.3 g/L in older vs 15.4 +/- 4.4 g/L for the younger, P = .740). Among the 64 patients who remained in the hospital 10 days subsequent to surgery, the average postoperative Day 10 serum albumin concentration was significantly lower in the older patients when compared with the younger (26.2 vs 29.1 g/L P = .016). Similar results were obtained for serum transferrin. CONCLUSIONS: Subsequent to elective arthroplasty, the magnitude of change in serum albumin and transferrin concentrations is similar in older compared with younger, patients, suggesting that this stress response to surgery is nor age dependent. In contrast, the rate of recovery of the serum protein concentrations to preoperative levels may be slower in the older patients. However, this issue needs to be investigated further.     

Subspecialty training in pediatric anesthesiology: what does it mean?

We evaluated the usefulness of the Duke criteria for diagnosing cases of active infective endocarditis (IE). Patients were identified prospectively over a 3-year period at 54 hospitals in the Philadelphia metropolitan area. Three of us independently reviewed abstracted hospital records and classified 410 patients as definite, probable, or possible cases of IE or as probable noncases. We then applied the Duke criteria to this sample to assess the degree of agreement between our diagnoses and the diagnoses based on these new criteria. Agreement was good to excellent, ranging from 72% to 90%, depending on the case definition used. The sensitivity of the Duke criteria was also good to excellent, varying from 71% to 99%, again depending on case definition used. Specificity was lower (0-89%). We conclude that use of the Duke criteria will result in little underdiagnosis of IE but that it may result in overdiagnosis of IE; therefore, these criteria should be applied prospectively to determine their clinical usefulness.