Variation In Alkaline Phosphatase Research Articles

Assessing Alkaline Phosphatase Reference Intervals Using Gamma-Glutamyl Transferase as a Surrogate for Normal Liver Function

Abstract Limited studies assess reference intervals (RIs) for hepatic enzymes, particularly for alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT). In the US, ALP and GGT RIs were established on Roche assays using a European cohort of ≤ 450 patients that may not reflect population variance. Further, age- and sex-specific variation in ALP and GGT may warrant tiered RIs, but evidence to justify this approach is limited. We aimed to evaluate the manufacturer’s RIs by comparing them to indirectly estimated RIs (IRIs). 217,333 AST, ALT, ALP, and GGT results (Roche c702) performed between 1/1/2019-12/31/2022 on outpatients ≥21 years were extracted from the laboratory information system. The first ALP for each patient was identified, and the earliest AST, ALT, and GGT drawn within 7 days was included. This approach was repeated for GGT. Concordance and correlation were calculated using Weighted Cohen’s Kappa and Spearman’s rank correlation coefficient respectively. {refineR} was applied to patients with “normal” liver function (defined as normal AST, ALT for all IRIs, plus normal GGT for ALP IRIs, and ALP for GGT IRIs). IRIs were estimated for all males, all females, females ≤50, and females >50 years and compared to the method specific manufacturer RI (ALP: 40-129 Units/L for males and 35-104 Units/L for females; GGT: 8-61 Units/L for males and 5-36 Units/L for females). Of the 71,783 outpatients, 54.9% were female, 74% self-identified as white and 19% as black. The median age was 58 (IQR: 43-68 years), the median ALP concentration was 77 (62-97 Units/L), and the median GGT concentration was 28 (17-57 Units/L). A moderate agreement (Kappa = 0.48, 95% confidence interval: 0.46-0.51) and positive correlation (r = 0.51; p<0.0001) between ALP and GGT was observed. For ALP and GGT, no significant differences were observed between the lower limit of the IRIs and the current RI. The upper limit of estimated IRIs was 132 [95% confidence interval: 117-147 Units/L] for patients with normal AST/ALT/GGT (n = 1596). For males, the sex-specific upper limit was 120 [101-140 Units/L] and for females, was 123 [110-136 Units/L]. Age stratified upper limits for females were 120 [101-140 Units/L], and 109 [97-121 Units/L] for ≤50 and >50 years, respectively. The upper limit for all patients with normal AST/ALT/ALP (n = 2,446) was 62 [55-70 Units/L]. For males, all females, females ≤50 and >50 years was 58 [46-69 Units/L], 40 [39-51 Units/L], 31 [23-39 Units/L], and 56 [41-71 Units/L]. Manufacturer RIs agreed well with the IRIs for most subsets, but differed for ALP IRIs of all females with normal hepatobilliary function and in GGT for all females and females >50 years. Further investigation of the impact of preselecting patient populations on IRIs and a direct RI study on select patient subsets is worth investigation.

A-093 Assessing Alkaline Phosphatase Reference Intervals Using Gamma-Glutamyl Transferase as a Surrogate for Normal Liver Function

Abstract Background There are limited published studies assessing reference intervals (RIs) for hepatic enzymes, particularly for alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT). In the US, ALP and GGT RIs were established on Roche assays using a European cohort of ≤ 450 patients that may not reflect population variance across practice settings. Further, age- and sex-specific variation in ALP and GGT may warrant tiered RIs, but evidence to justify this approach is limited. We aimed to evaluate the manufacturer’s RIs by comparing them to indirectly estimated RIs (IRIs) from routine clinical data. Methods 217,333 AST, ALT, ALP, and GGT results (Roche c702) performed between 1/1/2019-12/31/2022 on outpatients ≥21 years were extracted from the laboratory information system. The first ALP for each patient was identified, and the earliest AST, ALT, and GGT drawn within 7 days was included. This approach was repeated for GGT. Concordance and correlation were calculated using Weighted Cohen’s Kappa and Spearman’s rank correlation coefficient respectively. {refineR}, an algorithm for calculating IRIs, was applied to patients with “normal” liver function (defined as normal AST, ALT for all IRIs, plus normal GGT for ALP IRIs, and ALP for GGT IRIs). IRIs were estimated for all males, all females, females ≤50, and females >50 years and compared to the method specific manufacturer RI (ALP: 40-129 Units/L for males and 35-104 Units/L for females; GGT: 8-61 Units/L for males and 5-36 Units/L for females). Results Of the 71,783 outpatients, 54.9% were female, 74% self-identified as white and 19% as black. The median age was 58 (IQR: 43-68 years), the median ALP concentration was 77 (62-97 Units/L), and the median GGT concentration was 28 (17-57 Units/L). A moderate agreement between ALP and GGT was observed (Kappa = 0.48, 95% confidence interval: 0.46-0.51). A positive correlation between ALP and GGT was observed r = 0.51 (p<0.0001). For ALP, no significant differences were observed between the lower limit of the IRIs and the current RI. The upper limit of estimated IRIs was 132 [95% confidence interval: 117-147 Units/L] for patients with normal AST/ALT/GGT (n = 1596). For males, the sex-specific upper limit was 120 [101-140 Units/L] and for females, was 123 [110-136 Units/L]. Age stratified upper limits for females were 120 [101-140 Units/L], and 109 [97-121 Units/L] for ≤50 and >50 years, respectively. For GGT, no significant differences were observed for the lower limits. The upper limit for all patients with normal AST/ALT/ALP (n = 2,446) was 62 [55-70 Units/L]. For males, all females, females ≤50 and >50 years was 58 [46-69 Units/L], 40 [39-51 Units/L], 31 [23-39 Units/L], and 56 [41-71 Units/L]. Conclusions For the majority of patient subsets, the manufacturer RI agreed well with the IRIs. However, significant differences in IRIs were observed for the upper limit of ALP IRIs of all females with normal hepatobilliary function and in GGT for all females and females >50 years. Further investigation of the impact of preselecting patient populations on IRI estimation and a direct RI study on select patient subsets is worth investigation.

SERUM BIOCHEMISTRY AND SELECT MINERAL PARAMETERS OF PRE-RELEASE SUNDA PANGOLINS (MANIS JAVANICA) FOLLOWING REHABILITATION IN VIETNAM.

Native to Southeast Asia, the Sunda pangolin (Manis javanica) is critically endangered largely because of poorly regulated wildlife trade, consumptive practices, and use in traditional Chinese medicine. Efforts to rescue and rehabilitate animals confiscated from the illegal trade are complicated by a general lack of knowledge surrounding the normal health and disease processes unique to the species. To provide clinical reference intervals for normal health states of Sunda pangolins, biochemical parameters were determined from rescued individuals in Vietnam that had undergone a 14-day observation period and met a set of criteria for release back into the wild. Blood samples were collected from 42 apparently healthy Sunda pangolins while anesthetized or awake. Packed cell volume (PCV) and total solids (TS) were determined manually, and serum biochemistry values were determined in-house with a benchtop analyzer. Additional biochemical and mineral parameters not included in the primary panel were determined from a subset of 10 pangolins through an external diagnostic laboratory. Overall reference intervals were calculated for PCV and TS (n = 29) and for standard serum biochemistry parameters (n = 42). Females and males demonstrated significant variation with respect to body mass, potassium (K+), and phosphorus, whereas age was a significant source of variation in alkaline phosphatase. Seasonal variation in glucose (GLU), creatinine (CRE), total proteins, sodium, calcium, and K+ was also observed. Comparisons between anesthetized and awake pangolins demonstrated significant variation in GLU, CRE, and K+. The parameters determined in this study can serve as a clinical reference for ex situ Sunda pangolin conservation efforts. In the context of wildlife rehabilitation, serial bloodwork allows for continued monitoring of patient health and should inform decision making regarding release readiness and timing.

Inter- and Intra-individual Variation, and Limited Prognostic Utility, of Serum Alkaline Phosphatase in a Trial of Patients With Primary Sclerosing Cholangitis

Serum alkaline phosphatase (ALP) and the enhanced liver fibrosis (ELF) score are used as endpoints in trials of patients with primary sclerosing cholangitis (PSC). We aimed to quantify inter- and intra-individual variation in levels of ALP and the ELF score over time, and evaluated their association with fibrosis progression. We analyzed data from 234 patients with large-duct PSC enrolled in a 2-year, phase 2b placebo-controlled trial of simtuzumab. Participants were assessed by laboratory tests every 4 weeks, and liver biopsies collected at time of screening, week 48, and week96. Serum levels of ALP and ELF scores did not differ significantly between simtuzumab and placebo groups, so the data were pooled. Median per-patient variations in ALP between clinic visits were approximately 12% over 12 weeks, 20% over 48 weeks, and 20% over 96 weeks. Reductions, unrelated to study intervention, of more than 40% in ALP were observed in 10.9% of patients with baseline activity greater than 2-fold the upper limit of normal (ULN) and 12.5% of patients with more than 3-fold the ULN at 1 year. At 2 years, reductions of more than 40% in ALP were observed in 15.8% of patients with baseline activity greater than 2-fold the ULN and 17.9% of patients with more than 3-fold the ULN. Among the 209 patients with Ishak fibrosis stage 0-4 at baseline, serum ALP activity did not associate with development of cirrhosis or with a 2-point increase in fibrosis stage at 2 years. In contrast, the median per-patient variation in ELF scores between clinic visits was approximately 3% over 12 weeks, 4% over 48 weeks, and 4% over 96 weeks. Elevated ELF scores at baseline and at weeks 12, 24 and 48, each associated with development of cirrhosis at 2 years (odds ratio >2.75; P < .01 for all timepoints). ELF scores at baseline and weeks 12, 24 and 48, also associated with a 2-point increase in fibrosis stage at 2 years (odds ratios all greater than 2; P < .01 for all timepoints). In an analysis of data from patients with large-duct PSC enrolled in a prospective trial, we found large interindividual and intraindividual variations in serum ALP activity. Serum ALP activity did not associate with disease progression over a 2-year period. Variations in ELF score were smaller, and scores determined at multiple timepoints associated with fibrosis progression and development of cirrhosis.

Effects of resveratrol on bone health in type 2 diabetic patients. A double-blind randomized-controlled trial

ObjectivesPatients with type 2 diabetes (T2DM) are at increased fracture risk. Resveratrol has shown beneficial effects on bone health in few studies. The aim of this trial was to investigate the effects of resveratrol on bone mineral density (BMD) and on calcium metabolism biomarkers in T2DM patients.MethodsIn this double-blind randomized placebo-controlled trial 192 T2DM outpatients were randomized to receive resveratrol 500 mg/day (Resv500 arm), resveratrol 40 mg/day (Resv40 arm) or placebo for 6 months. BMD, bone mineral content (BMC), serum calcium, phosphorus, alkaline phosphatase, and 25-hydroxy vitamin D were measured at baseline and after 6 months.ResultsAt follow-up, calcium concentrations increased in all patients, while within-group variations in alkaline phosphatase were higher in both resveratrol arms, and 25-hydroxy vitamin D increased in the Resv500 arm only, without between-group differences. Whole-body BMD significantly decreased in the placebo group, while whole-body BMC decreased in both the placebo and Resv40 arms. No significant changes in BMD and BMC values occurred in the Resv500 arm. The adjusted mean differences of change from baseline were significantly different in the Resv500 arm vs placebo for whole-body BMD (0.01 vs −0.03 g/cm2, p = 0.001), whole-body BMC (4.04 vs −58.8 g, p < 0.001), whole-body T-score (0.15 vs −0.26), and serum phosphorus (0.07 vs −0.01 µmol/L, p = 0.002). In subgroup analyses, in Resv500 treated-patients BMD values increased to higher levels in those with lower calcium and 25-hydroxy vitamin D values, and in alcohol drinkers.ConclusionsSupplementation with 500 mg resveratrol prevented bone density loss in patients with T2DM, in particular, in those with unfavorable conditions at baseline.

Associations of udder-health indicators with cow factors and with intramammary infection in dairy cows

The objective of this study was to investigate if and how cow factors and intramammary infection (IMI) are associated with 4 different udder-health indicators in dairy cows as a first step in investigating whether the diagnostic performance of these indicators can be improved. The investigated indicators were somatic cell count (SCC), lactate dehydrogenase (LDH), N-acetyl-β-d-glucosaminidase (NAGase), and alkaline phosphatase (AP) measured in milk. In this cross-sectional study, approximately 1,000 cows from 25 dairy herds were sampled for bacteriology (quarter milk samples) during 3 consecutive days: the day before test milking, at the day of test milking, and at the day after test milking. The whole-udder test milking sample was analyzed for milk composition, SCC, LDH, NAGase, and AP. Cow data (parity, breed, milk yield, percentage of milk fat and protein, milk urea concentration, and days in milk from the sampled test milking) were collected from the Swedish milk-recording scheme. Of the sampled cows 485 were considered IMI negative and were used in multivariable mixed-effect linear regression models to investigate associations between cow factors and the udder-health indicators. A second modeling including all cows, both IMI negative and IMI positive (256 cows), was also performed. The results showed that all udder-health indicators were affected by cow factors but that different cow factors were associated with different indicators. Intramammary-infection status was significantly associated with all udder-health indicators except AP. Parity and milk urea concentration were the only cow factors associated with all indicators in all models. The significant cow factors explained 23% of the variation in SCC and >30% of the variation in LDH, NAGase, and AP in IMI-negative cows, showing that LDH, NAGase, and AP are more affected than SCC by cow factors. The IMI status explained 23% of the variation in SCC in the model with all cows but only 7% of the variation in LDH and 2% of the variation in NAGase, indicating that SCC has the best potential as a diagnostic tool in finding cows with IMI. However, further studies are needed to investigate whether the diagnostic properties of these udder-health indicators will improve with adjustment according to their associations with different cow factors when used as a diagnostic tool for finding cows with IMI.

Blood modifications associated with end stage renal disease duration, progression and cardiovascular mortality: a 3-year follow-up pilot study

Chronic kidney disease is a risk factor for cardiovascular mortality. This study uncovers pieces of hematological and erythrocyte protein variability observed in end stage renal disease (ESRD) in relation to disease progression/duration and mortality. Using a variety of experimental approaches, erythropoietin/dialysis-treated patients were compared to healthy individuals and had been followed for 36months. During that period, half of the patients died from cardiovascular diseases. The high levels of uremic toxins in those patients were associated with damaged erythrocytes, bad tolerance and poor response to hemodialysis therapy. The postmortem study revealed significant variation in alkaline phosphatase, duration of dialysis, erythrocyte transformation and intracellular hemoglobin concentration compared to the survived patients. The erythrocyte proteins showed substantial remodeling characteristic of pathologic regulation of cell hydration and susceptibility to the dialysis-induced oxidation defects. According to the follow-up study, duration of hemodialysis was associated with a trend towards increased intracellular hemoglobin concentration, membrane expression of glucose transporter-1 and stomatin as well as lower levels of circulating stomatocytes. The uremic index variation in long survived patients is accurately reflected in plasma and erythrocyte oxidative stress modifications. The ESRD patients exhibit impressive compensatory responses to the chronic challenges of the uremic milieu. This study demonstrates novel blood modifications probably associated with the duration of erythropoietin/hemodialysis treatment, disease progression and cardiovascular mortality in end stage renal disease. The observed variability adds new pieces to the erythrocyte pathophysiology puzzle in end stage renal disease and suggests novel hematologic and proteomic factors for consideration in future large scale studies on cardiovascular morbidity and mortality candidate biomarkers in uremic patients.

Alkaline phosphatase variation during carfilzomib treatment is associated with best response in multiple myeloma patients

The ubiquitin-proteasome pathway regulates bone formation through osteoblast differentiation. We analyzed variation alkaline phosphatase (ALP) during carfilzomib treatment. Data from 38 patients enrolled in the PX-171-003 and 29 patients in PX-171-004 studies, for patients with relapsed/refractory myeloma, were analyzed. All patients received 20 mg/m(2) of carfilzomib on Days 1, 2, 8, 9, 15, and 16 of a 28-day cycle. Sixty-seven patients from ALP data were evaluable. In PX-171-003, the ORR (>PR) was 18% and the clinical benefit response (CBR; >MR) was 26%, while in PX-171-004, the ORR was 35.5% overall and 57% in bortezomib-naive patients. ALP increment from baseline was statistically different in patients who achieved ≥ VGPR compared with all others on Days 1 (P = 0.0049) and 8 (P = 0.006) of Cycle 2. In patients achieving a VGPR or better, ALP increased more than 15 units per liter at Cycle 2 Day 1 over baseline. An ALP increase over the same period of time was seen in 26%, 13% and 11% of patients achieving PR, MR, and SD, respectively. This retrospective analysis of patients with relapsed or refractory myeloma treated with single-agent carfilzomib indicates that early elevation in ALP is associated with subsequent myeloma response.

2009년 추계와 동계 가막만 북부해역에서 alkaline phosphatase 활성과 phosphatase 가수 분해성 인의 분포 특성

We investigated variations in alkaline phosphatase (APase) activity and alkaline phosphatase hydrolyzable phosphorus (APHP) in northern Gamak Bay from September to December 2009. Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) decreased gradually, and the DIN/DIP ratio was higher than the Redfield ratio (16) based on molecular concentrations during most of the observation period. The total APase (T-APase) activity increased with decreasing DIP concentration; i.e., the Relationship between T-APase and DIP showed a high negative correlation (r=-0.80, P<0.001), with APase activity being a good indicator of DIP limiting the Redfield ratio. The T-APase was positively correlated with the concentration of chlorophyll a (r=0.73, P<0.001). This suggests that a major portion of APase activity in northen Gamak Bay seawater is attributed to phytoplankton. The proportion of APHP among dissolved organic phosphorus (DOP) was low in September and high in November. Thus, APase-producing phytoplankton may be able to grow by utilizing APHP as a phosphorus source in autumn when DIP is limiting. Thus, APase activity and the use of DOP by phytoplankton may play an important role in the growth of phytoplankton under DIP limiting conditions such as those of northern Gamak Bay.

Alkaline phosphatase as a reporter of σS levels and rpoS polymorphisms in different E. coli strains

sigma(S) is responsible for the transcriptional regulation of genes related to protection against stresses and bacterial survival and it accumulates in the cell under conditions of stress, such as nutrient limitation. An increase in the levels of sigma(S) causes a reduction in the expression of genes that are transcribed by RNA polymerase associated with the principal sigma factor, sigma(70). phoA, that encodes alkaline phosphatase (AP) is expressed under phosphate shortage conditions, and is also repressed by sigma(S). Here we show that in a Pi-limited chemostat, accumulation of rpoS mutations is proportional to the intrinsic level of sigma(S) in the cells. Acquisition of mutations in rpoS relieves repression of the PHO genes. We also devised a non-destructive method based on the rpoS effect on AP that differentiates between rpoS (+) and rpoS mutants, as well as between high and low-sigma(S) producers. Using this method, we provide evidence that sigma(S) contributes to the repression of AP under conditions of Pi excess and that AP variation among different strains is at least partly due to intrinsic variation in sigma(S) levels. Consequently, a simple and non-destructive AP assay can be employed to differentiate between strains expressing different levels of sigma(S) on agar plates.

Response to bortezomib (BOR) and bone metabolism in multiple myeloma patients

6536 Background: Evidence of osteoblastic activation was first observed at our Institution in patients with progressive multiple myeloma (MM) during treatment with bortezomib (VELCADE). Osteoblastic activation, based on isolated alkaline phosphatase (ALP) elevation (without alteration of other liver function tests) with a parallel increase in bone specific ALP and parathyroid hormone, was noted to be associated to response. ALP variation was subsequently assessed in 182 MM patients treated with BOR on the SUMMIT trial. A significant difference in isolated ALP elevation was observed in patients achieving ≥ PR (≥50% paraprotein reduction using EBMT criteria) compared to the other patients (P = 0.02). Methods: In this study we report ALP variation in 584 patients with normal liver function at baseline and treated in the randomized open label phase III APEX trial (Millennium protocol M34101–039). Patients with relapsed or progressive disease after at least one prior therapy were enrolled in the study, which c...

Study of strontium and boron as antidotes to fluoride toxicity

The recovery from fluoride toxicity of white mice by strontium (Sr) and boron (B) was investigated. With the 2 mg NaF/kg body weight B.W./d treatment for 6 months, the body weights and the fluoride levels in livers of white mice had no significant changes in comparison with the control. However, the fluoride contents in bones sharply increased (p <0.01) after 1.5 months treatment. No significant variation in alkaline phosphatase (ALP) activity in serum was observed after 1.5 and 3.0 months NaF treatment, whereas, with NaF administration for 4.5 and 6.0 months, the ALP activities increased markedly (p <0.01). The ALP activity in kidneys was significantly higher than the control (p <0.01) after the white mice had maintained on water containing NaF for 1.5 months. When 2mg NaF/kg B.W./d was administered with 0.8 mg B/kg B.W./d and 1 mg Sr/kg B.W./d concurrently, fluoride levels in bones and ALP activities in serum and kidney was reduced compared with individual treatment of fluoride, which suggested that Sr and B could antagonize fluoride toxicity. The extent of recovery was somewhat more pronounced by B treatment than by Sr administration.

Age-related changes of plasma alkaline phosphatase and inorganic phosphorus, and late ossification of the cranial roof in the Spanish imperial eagle (Aquila adalberti C. L. Brehm, 1861).

Plasma alkaline phosphatase and inorganic phosphorus levels were determined for 52 nestling Spanish imperial eagles from two wild populations and 22 captive adults and subadults (10 adults and 12 subadults). The exact age was known for all birds. Mean alkaline phosphatase and inorganic phosphorus were higher in chicks than in the captive adults and subadults. Sex differences were not observed, and nestlings from different populations showed similar values. No significant regression described the relationship between age and alkaline phosphatase or inorganic phosphorus throughout the nestling period. However, alkaline phosphatase and inorganic phosphorus decreased significantly throughout the subadult period, with age explaining 98.2% and 50.5% of the variation in alkaline phosphatase and inorganic phosphorus levels, respectively. Non-fully-ossified zones were measured in frontal bones of another 12 subadult eagles that died at known ages. Ossification increased throughout the subadult period and was significantly correlated with expected levels of alkaline phosphatase or inorganic phosphorus (i.e., values predicted from the regression equations derived from the first analysis). Minimum alkaline phosphatase levels and full ossification of the cranial roof coincided with puberty onset. We conclude that, in subadult Spanish imperial eagles, decreasing alkaline phosphatase and inorganic phosphorus values are related to the ossification of frontal bones, although a contribution of other unknown processes of late ossification cannot be excluded, and alkaline phosphatase (but not inorganic phosphorus) may be a useful parameter for age-predicting purposes.

Phosphate and phosphatase distribution in sediment depths of rockphosphate treated carp culture system

Distribution pattern of phosphates (A1-P, Ca-P, Fe-P), available-P, citrate soluble-P and phosphatases (acid and alkaline) was examined in three sediment layers (0–2.5 cm, 2.6–5.0 cm, 5.1–7.5 cm) of carp (Cirrhinus mrigala) culture system fertilized with varying levels (43.66 kg and 87.32 kg P) and frequencies (7, 15 and 30 days) of rock phosphate. Whereas layer differences of phosphate and phosphatases were significant in any of the treatments employed, significant treatment differences were restricted to first and second layer, but not in third layer implying that uppermost layer was the most active site of treatment action. Large variations in fish yield among six treatments were directly related with P-content of surface sediments, and hence P-level of overlying water. The variations of alkaline phosphatases in the first layer of sediment in each treatment was strongly influenced by Al-P (99.78%), available-P (0.16%) and Fe-P(0.05%), whereas the variations in second layer was mainly affected by Al-P (99.02%). None of these factors were related to the small variations of alkaline phosphatase in third layer of sediment.

Constancy of enzyme electrofocusing patterns in a stand of the lichen Umbilicaria mammulata

Thalli of the lichen Umbilicaria mammulata (Ach.) Tuck, were collected from one site, 24 at each of five different sampling times, over a period of 1 year. Protein extracts from each individual thallus were subjected to isoelectric focusing, followed by specific staining for eight enzyme systems (mannitol dehydrogenase, isocitrate dehydrogenase, 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, superoxide dismutase, esterase, and alkaline phosphatase). A total of 55 bands were resolved, 25 of which were constant in all thalli through all sampling dates. Principal components analysis of the electromorph data showed the existence of groups corresponding to sets of thalli collected at the same times; esterase and alkaline phosphatase variation were primarily responsible for these groupings. Banding patterns of 6-phosphogluconate dehydrogenase and superoxide dismutase were constant regardless of date of collection. Most bands of glucose-6-phosphate dehydrogenase and glutamate dehydrogenase were consistent through all sampling times, but each system exhibited one band that differed in frequency from one collection date to another. Electromorphs of mannitol dehydrogenase and isocitrate dehydrogenase exhibited only minor variability. Dehydrogenase enzymes, since they tended to vary least from one sampling time to the next, can thus be used more readily for taxonomic purposes. If esterases and alkaline phosphatases are to be applied as taxonomic criteria, samples for comparison should be collected simultaneously.

Alkaline Phosphatase and the international Clinical Enzyme Scale

The wide numeric variation of alkaline phosphatase (ALP: EC 3.1.3.1) values reported from clinical laboratories is clearly revealed by the grossly incompatible data found in large interlaboratory surveys. The authors suggest that this unsatisfactory situation is readily correctable by simply expressing all numeric results on a single scale, the International Clinical Enzyme Scale (ICES). ICES for ALP (ALP/ICES) rests upon a well-defined reference system that relates the IFCC Reference Method for ALP to numerous stable primary and secondary ALP reference materials. The authors show by calibrations with ALP/ICES reference materials that raw coefficients of variation of 25-30% due to reagent, temperature, or instrument differences could be reduced to as low as 2%. ICES and the reference system approach automatically unifies the numeric outputs of the working clinical laboratories by relating all measurements and reference materials to one clearly defined international reference method, yet this concept allows many technologic options in the individual laboratory.

Seasonal Changes in the Activity of Serum Alkaline Phosphatase

This paper reports a seasonal variation in alkaline phosphatase (ALP) levels in the serum, with low values occurring in summer and high in winter. These variations were found both in indoor and outdoor workers and in a group of elderly women in a long-stay ward. The seasonal change in ALP was in the opposite direction to the seasonal change in the serum levels of 25-hydroxyvitamin D. No such change was seen in the serum levels of gamma-glutamyltransferase. It is suggested that the seasonal change in plasma ALP could be due to changes in the bone isoenzyme. Serum levels of calcium remained unchanged; the change in ALP may reflect a homeostatic mechanism controlling plasma calcium, which compensates for seasonal variations in vitamin D supply.

Genetic variation in alkaline phosphatase of the house mouse (Mus musculus) with emphasis on a manganese-requiring isozyme.

Genetic variation among inbred strains is described for electrophoretic migration of alkaline phosphatase from intestine, kidney, blood plasma, and three isozymes of liver. A manganese-requiring isozyme of liver and kidney unaffected by neuraminidase is described, and the locus controlling variation in this isozyme is designated Akp-1. Data from recombinant inbred strains place the locus on chromosome 1 at a distance of 3.6 +/- 2.9 cM from the M1s locus on the side distal to the centromere. Test-cross data show the following gene order and recombination percentages: Dip-1 19.0 +/- 3.8% Lp 7.4 +/- 2.2% Akp-1.

Histoenzymological study of dermal vessels in normal and pathological skin.

Summary— Twenty specimens of normal skin, taken from 8 different areas and 61 specimens from patients suffering from psoriasis, scleroderma (sclerodactyly), angiomas, basal-cell and squamous-cell carcinomas were studied histochemically for 13 enzyme activities. Alkaline phosphatase (AP) and adenosine triphosphatases are mainly useful in revealing the vascular pattern of the dermis, ATP'ases showing activity in larger vessels than AP. On the other hand, some metabolic changes in the vascular wall may be indicated by variations in AP and ATP'ase activities. The various other enzyme activities deserve studying for their metabolic significance. While in normal skin vessels, dehydrogenases of the glycolytic pathway are the most active, in pathological conditions like psoriasis, and carcinomas, other activities appear stronger: G6P-DH, aconitase and IC-DH.

Variation in alkaline phosphatase results using the method of Bessey, Lowry and Brock

Variation in alkaline phosphatase results using the method of Bessey, Lowry and Brock