700,000 years of tropical Andean glaciation.

Our understanding of the climatic teleconnections that drove ice-age cycles has been limited by a paucity of well-dated tropical records of glaciation that span several glacial-interglacial intervals. Glacial deposits offer discrete snapshots of glacier extent but cannot provide the continuous records required for detailed interhemispheric comparisons. By contrast, lakes located within glaciated catchments can provide continuous archives of upstream glacial activity, but few such records extend beyond the last glacial cycle. Here a piston core from Lake Junín in the uppermost Amazon basin provides the first, to our knowledge, continuous, independently dated archive of tropical glaciation spanning 700,000 years. We find that tropical glaciers tracked changes in global ice volume and followed a clear approximately 100,000-year periodicity. An enhancement in the extent of tropical Andean glaciers relative to global ice volume occurred between 200,000 and 400,000 years ago, during sustained intervals of regionally elevated hydrologic balance that modified the regular approximately 23,000-year pacing of monsoon-driven precipitation. Millennial-scale variations in the extent of tropical Andean glaciers during the last glacial cycle were driven by variations in regional monsoon strength that were linked to temperature perturbations in Greenland ice cores1; these interhemispheric connections may have existed during previous glacial cycles.

Osteogenesis imperfecta and the teeth, eyes, and ears-a study of non-skeletal phenotypes in adults.

Osteogenesis imperfecta (OI) is a disease causing bone fragility; however, it potentially affects all organs with a high content of collagen, including ears, teeth, and eyes. The study is cross-sectional and compares non-skeletal characteristics in adults with OI that clinicians should be aware of when caring for patients with OI. INTRODUCTION: Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder. The skeletal fragility is pronounced; however, OI leads to a number of extra-skeletal symptoms related to the ubiquity of collagen type 1 throughout the human body. The vast majority of knowledge is derived from studies performed in the pediatric population. Thus, we aimed to investigate the nature and prevalence of ophthalmologic, odontologic, and otologic phenotypes in an adult population with OI. METHODS: The study population comprises 85 Danish OI patients (age 44.9 ± 15.9 years). Fifty-eight patients had OI type I, 12 OI type III, and 15 OI type IV according to the classification by Sillence. Audiometric evaluations and dental examinations were performed in 62 and 73 patients, respectively. Ophthalmologic investigations were performed in 64 patients, including measurements of the central corneal thickness. RESULTS: All patients, except two, had corneal thickness below the normal reference value. Patients with OI type I and patients with a quantitative collagen defect had thinner corneas compared to patients with OI type III and other patients with a qualitative collagen defect. One patient in this cohort was diagnosed with and treated for acute glaucoma. Dentinogenesis imperfecta was diagnosed in one fourth of the patients, based on clinical and radiographic findings. This condition was predominately seen in patients with moderate to severe OI. Hearing loss requiring treatment was found in 15 of 62 patients, of whom three were untreated. The most prevalent type of hearing loss (HL) was sensorineural hearing loss, whereas conductive HL was solely seen in patients with OI type III. The patients with the most severe degrees of HL were patients with mild forms of OI. Age was associated with increased HL. CONCLUSION: Although significant health problems outside the skeleton are frequent in adult patients with OI, the patients are not consistently monitored and treated for their symptoms. Clinicians treating adult patients with OI should be aware of non-skeletal health issues and consider including regular interdisciplinary check-ups in the management plan for adult OI patients.

Safety evaluation of orally administered afoxolaner and milbemycin oxime in eight-week-old dogs.

The safety profile of afoxolaner (an isoxazoline molecule) when combined with milbemycin oxime (a macrocyclic lactone) was evaluated according to the regulatory requirements when administered six times orally in a soft chewable formulation at a dose of at least 1×, 3×, or 5× the maximum exposure dose in 8-week-old Beagle dogs. Thirty-two healthy puppies (16 males and 16 females) were enrolled and allocated randomly to one of four treatment groups. Three doses were administered at 28-day intervals (Days 0, 28, and 56), followed by three additional doses administered with 14-day intervals (Days 84, 98, and 112). The study ended on Day 126. Treatment groups were as follows: Group 1: untreated, sham-dosed control; Group 2: afoxolaner/milbemycin oxime chews administered at a dose of at least 5 and 1 mg/kg, respectively (1×); Group 3: afoxolaner/milbemycin oxime chews administered at a dose of at least 15 and 3 mg/kg, respectively (3); and Group 4: afoxolaner/milbemycin oxime chews administered at a dose of at least 25 and 5 mg/kg, respectively (5×). All dogs were examined for general health twice a day beginning on Day -14. Physical examinations, and blood collections for clinical pathology analysis and afoxolaner and milbemycin oxime plasma concentrations, were performed throughout the study. No afoxolaner/milbemycin oxime treatment-related changes were observed in growth, physical variables, clinical pathology variables, or tissues examined histologically. No clinically relevant or statistically significant health abnormalities related to the administration of afoxolaner/milbemycin oxime were observed. No signs of macrocyclic lactone sensitivity were observed at any time during the study. Vomiting and diarrhea were observed sporadically across all groups including the controls. Based upon the results of this study, afoxolaner/milbemycin oxime soft chewables were shown to be safe when administered repeatedly at up to 5× the maximum exposure dose in dogs as young as 8 weeks of age.

Major change in regiospecificity for the exo-1,3-ß-glucanase from Candida albicans following its conversion to a glycosynthase.

The exo-1,3-ß-glucanase (Exg) from Candida albicans is involved in cell wall ß-d-glucan metabolism and morphogenesis through its hydrolase and transglycosidase activities. Previous work has shown that both these activities strongly favor ß-1,3-linkages. The E292S Exg variant displayed modest glycosynthase activity using α-d-glucopyranosyl fluoride (α-GlcF) as the donor and pNP-ß-d-glucopyranoside (pNPGlc) as the acceptor but surprisingly showed a marked preference for synthesizing ß-1,6-linked over ß-1,3- and ß-1,4-linked disaccharide products. With pNPXyl as the acceptor, the preference became ß-1,4 over ß-1,3. The crystal structure of the glycosynthase bound to both of its substrates, α-GlcF and pNPGlc, is the first such ternary complex structure to be determined. The results revealed that the donor bound in the -1 subsite, as expected, while the acceptor was oriented in the +1 subsite to facilitate ß-1,6-linkage, thereby supporting the results from solution studies. A second crystal structure containing the major product of glycosynthesis, pNP-gentiobiose, showed that the -1 subsite allows another docking position for the terminal sugar; i.e., one position is set up for catalysis, whereas the other is an intermediate stage prior to the displacement of water from the active site by the incoming sugar hydroxyls. The +1 subsite, an aromatic "clamp", permits several different sugar positions and orientations, including a 180° flip that explains the observed variable regiospecificity. The p-nitrophenyl group on the acceptor most likely influences the unexpectedly observed ß-1,6-specificity through its interaction with F229. These results demonstrate that tailoring the specificity of a particular glycosynthase depends not only on the chemical structure of the acceptor but also on understanding the structural basis of the promiscuity of the native enzyme.

Variability in platelet- and collagen-binding defects in type 2M von Willebrand disease.

Type 2M von Willebrand disease (VWD) includes qualitative defects in von Willebrand factor (VWF) function, with normal multimer distribution but a defect in VWF activity with respect to platelet or collagen binding. We characterized novel VWF gene mutations found in type 2M VWD subjects enrolled in the Zimmerman Program for the Molecular and Clinical Biology of VWD. Subjects were enrolled based on a pre-existing diagnosis of type 2M VWD. Testing included full-length gene sequencing, VWF antigen (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), VWF collagen binding and multimer distribution. Recombinant VWF variants were synthesized using site-directed mutagenesis and expressed in HEK293T cells. Platelet binding was measured by flow cytometry with fixed platelets and ELISA with recombinant glycoprotein Ibα (GPIbα). Four novel VWF A1 domain mutations were found in individuals with type 2M VWD: S1358N, S1387I, S1394F and Q1402P. All subjects had a history of bleeding, VWF:RCo < 40 IU dL(-1) , VWF:RCo/VWF:Ag ratios <0.6 and normal multimer distribution. No defect in expression, secretion, or multimerization was found for any of the mutations. All showed decreased binding to intact platelets, and decreased or absent binding to a mutant GPIbα construct with spontaneous VWF binding. 1387I had decreased binding to all collagen types tested. 1402P had reduced binding exclusively to type VI collagen. Type 2M VWD is a heterogeneous category comprised of both collagen- and platelet-binding defects. Understanding the precise defect for each mutation may ultimately lead to better diagnosis and treatment.

Investigation of two novel biochemical markers of inflammation, matrix metalloproteinase and cathepsin generated fragments of C-reactive protein, in patients with ankylosing spondylitis.

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic inflammation of the spine and the sacroiliac joints. Current markers of inflammation, such as C-reactive protein (CRP), are reflecting the production of an acute phase reactant rather than tissue specific inflammation, but the use of CRP as a diagnostic and prognostic marker for AS has not provided the sought accuracy and specificity. We hypothesized that local enzymatic activity in the disease-affected tissue, which is associated with extensive tissue turnover may, by cleavage, modify the CRP produced in the liver. These cleavage products may provide additional information on systemic inflammation as compared to that of full-length CRP. We investigated whether these CRP degradation products would provide additional diagnostic value in AS patients compared to full-length CRP. METHODS: CRP fragments were identified by mass-spectrometry. Two fragments were selected for ELISA development. One assay exclusively identified a matrix metalloproteinase (MMP) generated fragment, CRP-MMP, whereas the other assay identified a cathepsin generated fragment, CRP-CAT. Full-length CRP, CRP-MMP and CRP-CAT were measured in serum samples from 40 AS patients and 40 sex- and age-matched controls. RESULTS: Full-length CRP was not elevated in AS patients compared to controls, whereas CRP-MMP was elevated by 25% (p<0.001) and CRP-CAT by 50% (p<0.0001). The Area Under Curve of the Receiver-Operator Characteristic curve of CRP-CAT was the highest with 77%. CONCLUSIONS: MMP and cathepsin degraded CRP provided more discriminative diagnostic potential compared to that of full-length CRP in this current study. These data suggest that different pools of CRP may provide insight into the inflammation processes in AS.

Empirical Explorations of SYNCHEM.

During the past several years, a substantial body of experience has accumulated in the use of SYNCHEM, a large-scale program which is able to discover synthesis routes for relatively complex organic structures without on-line guidance on the part of its chemist user. These results indicate that the approach to computer-directed organic synthesis route discovery embodied in the program has been valid and reasonable, and that SYNCHEM is likely to be fruitful from the point of view of its intended users as well as for our research objectives in artificial intelligence. The experiments have revealed a number of insufficiencies in the program as well. Most of these are rectified in SYNCHEM2, a revised version of the program which includes, among other improvements, a more highly developed synthesis search algorithm and the routine consideration of stereochemistry.

Corticosteroid administration alters the mechanical properties of isolated collagen fascicles in rat-tail tendon.

Overload tendon injuries are frequent in recreational and elite sports. The optimal treatment strategy remains unknown, but local administration of corticosteroids is one common treatment option. The direct effects of the corticosteroid administration on the tissue are not fully understood. The present study examined the biomechanical effects of intratendinous corticosteroid injections on healthy rat-tail tendon collagen fascicles. A total of 24 Wistar male rats were divided into (A) a corticosteroid group where the animals were injected in the tail tendon with methylprednisolone acetate, 1.0 mL of 40 mg/mL mixed with 1.0 mL 9% saline (n=12), and (B) a control group that was injected with 9% saline (n=12). Three days after the injections, the animals were sacrificed and single individual collagen fascicles were collected and underwent displacement to failure. Corticosteroid administration significantly reduced tensile fascicle yield strength by 16% and Young's modulus by 14% compared with sham treatment (10.5+/-0.8 vs 12.4+/-0.5 MPa, P< or =0.05, and 537+/-27 vs 641+/-30 MPa, P<0.05, respectively), while the strain properties were unaffected. Peak stress was similar between the two groups. There was no difference in fascicle diameter between the two groups.

Oral transmucosal fentanyl citrate versus placebo for painful dressing changes: a crossover trial.

OBJECTIVE: Fentanyl is a potent opioid that is well absorbed via the oral mucosa. It can be given as an oral lozenge. The onset of analgesia is rapid and matches the pain profile observed at dressing changes. METHOD: Patients experiencing pain during daily dressing changes were given entonox plus either placebo or oral transmucosal fentanyl citrate (OTFC) for two consecutive dressing changes in a randomised double-blind placebo-controlled crossover trial. RESULTS: Nine patients were recruited. The mean worst pain score during dressing changes was 7/10 with placebo and 4/10 with OTFC; the reduction in pain achieved with OTFC was significant. The mean number of breaths of entonox taken during the dressing change was 27.67 with placebo and 4.67 with OTFC; the reduction in the number of entonox breaths with OTFC was significant. One patient in the OTFC group suffered nausea. CONCLUSION: Compared with placebo, OTFC improved analgesia during painful dressing changes without an increase in side-effects.

Implementing a systematic response to medication errors.

Healthcare delivery is associated with various risks and it is unlikely that these can ever be completely eliminated. Medicine management is an area known to involve errors. This article describes how implementing a systematic response to medication errors enables health professionals to identify individual and organisational failures and reduce adverse patient outcomes.

Efficacy of afoxolaner plus milbemycin oxime chewable tablets (NexGard Spectra®, Merial) against adult Ancylostoma ceylanicum hookworm, in dogs.

A fixed-combination chewable tablet incorporating afoxolaner plus milbemycin oxime (NexGard Spectra®, Merial) was tested in purpose-bred Beagle dogs for efficacy against adult Ancylostoma ceylanicum hookworms. Sixteen dogs were inoculated each by oral administration of approximately 500 infective larvae of A. ceylanicum. Seventeen days after inoculation, the dogs were weighed and allocated randomly to be treated with afoxolaner plus milbemycin oxime chewable tablets or to remain untreated. Commercial chewable tablets of different strength were combined to deliver doses as close as possible to the minimum effective dose of 2.5mg afoxolaner plus 0.5mg milbemycin oxime per kg body weight. Parasites were recovered and counted for determination of efficacy seven days after treatment. All eight dogs that had been left untreated were harboring adult A. ceylanicum (geometric mean, 317.8; range, 210-428) while only one and nine A. ceylanicum were recovered from two of the eight dogs treated with afoxolaner plus milbemycin oxime chewable tablets (geometric mean, 0.5; p<0.0001). Thus, 99.9% efficacy against induced infection of A. ceylanicum was obtained by the use of oral NexGard Spectra® at the minimum effective dose. Treatment with afoxolaner plus milbemycin oxime chewable tablets was well accepted and safe.

Effects of local infusion of OP-1 on particle-induced and NSAID-induced inhibition of bone ingrowth in vivo.

Excessive polyethylene wear particles from joint replacements may lead to periprosthetic osteolysis and loosening. Nonsteroidal anti-inflammatory drugs (NSAIDs) decrease fracture healing and bone ingrowth. We hypothesized that continuous local infusion of OP-1 (BMP-7) would increase local bone formation in the presence of two different adverse stimuli, polyethylene particles, and an oral NSAID. The Drug Test Chamber (DTC) was implanted in the proximal tibia of mature rabbits. The tissue growing into the chamber was exposed to OP-1 solution (110 ng/day), which was infused via an osmotic pump. Infusion of OP-1 alone for 6 weeks enhanced local bone formation in the chamber by 80% (p < 0.05) over infusion of carrier alone. In the presence of polyethylene particles, infusion of OP-1 increased local bone formation by 38% (p < 0.05) over treatment with particles and carrier. Oral administration of NSAID reduced local bone formation by 58% (p < 0.05); this suppressive effect caused by NSAIDS was completely reversed by the infusion of OP-1 (p < 0.05). These findings underline a potential role for local treatment with OP-1 to increase bone formation in the presence of potentially adverse stimuli such as polyethylene wear particles or NSAID use.

Ability of an oral formulation of afoxolaner to protect dogs from Borrelia burgdorferi infection transmitted by wild Ixodes scapularis ticks.

A randomized, blinded, negative controlled study was conducted to determine whether treatment with afoxolaner (NexGard®, Merial, Inc.) would prevent the transmission of Borrelia burgdorferi to dogs by wild caught Ixodes scapularis ticks. Twenty healthy dogs were randomly assigned to two groups of ten dogs each. Ten dogs were treated orally on Day 0 at a dose near the minimum recommended dose of afoxolaner of 2.5mg/kg (actual doses 2.5-3.1mg/kg) and ten control dogs were not treated. On Day 28, each dog was infested with approximately 50 adult unfed wild caught I. scapularis that had a 67% B. burgdorferi infection rate (determined by polymerase chain reaction). On Day 33, live ticks were counted and removed. No ticks were found on treated dogs while control dogs had an average of 21.4 ticks. To detect infection, the B. burgdorferi-specific C6 antibody SNAP® 4Dx® test (IDEXX) was performed on serum collected before infestation (all dogs seronegative on Days -6 and 27) and on Days 48, 63, 77 and 92. The ten treated dogs remained seronegative through the end of the study (Day 92), while nine out of the ten control dogs were infected, as demonstrated by their seroconversion to being positive for the presence of the B. burgdorferi-specific C6 antibody starting on Day 48. In this study, all dogs treated with NexGard® 28days prior to challenge with wild caught I. scapularis ticks were protected from B. burgdorferi infection, while nine out of the ten untreated control dogs were infected.

Identification and immunochemical characterization of a major placental secretory protein related to the prolactin-growth hormone family, prolactin-like protein-C.

Trophoblast cells of the rat chorioallantoic placenta synthesize and secrete a number of proteins structurally related to pituitary PRL. During the purification of one member of the placental PRL family, PRL-like protein-A (PLP-A), we identified a major contaminating protein with a similar mol wt but possessing a more acidic pI (5.9-6.1) and different immunoreactivities. After isolation by two-dimensional gel electrophoresis, the more acidic contaminating protein was electroeluted, and its N-terminal amino acid sequence was determined by gas phase sequencing. The N-terminal sequence showed considerable homology with members of the PRL family, including characteristic positioning of cysteine residues at amino acids 4 and 11. The newly identified protein species have been termed PLP-C based on their structural similarity with pituitary PRL. The protein was further characterized by the generation of specific immunological probes. Antibodies were generated to electrophoretically purified protein and to a chemically synthesized peptide representing amino acids 11-32 of its N-terminal sequence. Each antiserum specifically recognized two major species migrating at approximately 25 and 29 kDa, respectively. The 29-kDa species specifically bound to Concanavalin-A, while the 25-kDa species failed to bind to the lectin. Furthermore, the 29-kDa species could be converted to the 25-kDa species by enzymatic deglycosylation. The antisera have also been used to examine the cell- and temporal-specific patterns of expression. The immunoreactive protein species (25 and 29 kDa) were localized primarily to spongiotrophoblast cells present in the junctional zone of the chorioallantoic placenta. Expression was initiated after midgestation and increased during the remaining part of gestation. In summary, PLP-C is a major secretory protein produced by spongiotrophoblast cells during the second half of gestation.

Irregular breathing during sleep in patients with panic disorder.

OBJECTIVE: The authors examined the nocturnal breathing patterns of patients with panic disorder to determine whether these individuals had respiratory irregularities at a time when anxiety was not manifest. METHOD: Respiratory polysomnography was conducted on 14 medication-free patients with panic disorder and 14 healthy comparison subjects. Semiautomated indices of ventilatory variability were calculated for representative 3-minute, artifact-free sleep samples, and manually scored indices of irregular breathing were rated (blind to diagnosis) for the entire last 2 nights of sleep. RESULTS: Patients with panic disorder had evidence of abnormal sleep breathing as indicated by increased irregularity in tidal volume during REM and an increased rate of microapneas (i.e., brief [5-10-second] pauses in breathing). A subgroup of patients (including some with recent sleep panic attacks) had indices of subtle disorders in breathing during sleep that were above the 95th percentile for the comparison subjects. CONCLUSIONS: These findings extend the observations in the awake state that patients with panic disorder breathe more irregularly than healthy comparison subjects. The irregularities may be attributable to altered brainstem sensitivity to CO2 or to other as yet unexplained factors. A possible relationship between irregular nocturnal breathing and sleep panic attacks is discussed.

Exploratory factor analysis of the Pain Anxiety Symptoms Scale in patients with chronic pain complaints.

The Pain Anxiety Symptoms Scale (PASS) is a 40-item self-report measure that consists of four subscales measuring aspects of pain-related anxiety and avoidance. Despite its growing popularity, there have been few studies of its psychometric properties. The primary purpose of this study was to determine the factor structure of the PASS in a sample of 259 chronic pain patients. Principal component analysis with oblique (Oblimin) rotation provided partial support for the factorial validity of the PASS. Five factors were extracted: (1) catastrophic thoughts, (2) physiological anxiety symptoms, (3) escape/avoidance behaviours, (4) cognitive interference, and (5) coping strategies. The use of analgesic medication did not influence the factor solution. The factors were characterised by correlating them with pain-related measures, and with measures of mood state. Implications are considered for revising the PASS subscales to provide a more comprehensive and factorially valid assessment of pain-related fear and avoidance.

Active-site-directed alkylation of chymotrypsin by reagents utilizing various departing groups.

Affinity-labeling reagents are useful for the inactivation of proteases in vivo but are apparently limited in application by the possibility of side reactions. In addition, increased specificity would be desirable. Substrate-derived chloromethyl ketones, one class of protease inhibitors, have been examined with the hope that replacement of the departing group halogen by other substituents might lead to improved inhibitor characteristics. Analogues of Z-Phe-Ch2X were synthesized in which X is a sulfonate or carboxylate substituent and examined as inactivators of chymotrypsin. The sulfonate esters were found to be more reactive than the previously studied halogen derivatives.

Echocardiographic predictors of survival in low gradient aortic stenosis.

Echocardiographic predictors of long-term survival for patients with low gradient aortic stenosis who undergo aortic valve replacement have not been previously reported. This study shows that patients with larger pre- and postoperative left ventricular volumes, a lower mean preoperative aortic pressure gradient, and failure of volumes to decrease and ejection fraction to increase postoperatively may have a poor prognosis.

Trophoendodermal stem cell-derived extracellular matrices: absence of detectable entactin and presence of multiple laminin species.

Extracellular matrices (ECM) generated by trophoendodermal stem cells transplanted into the peritoneum of host rats were investigated. Two types of trophoendodermal transplants were studied: (1) free-floating cystic structures, and (2) solid masses adherent to various abdominal organs. Trophoendodermal stem cell ECM obtained from either transplant source was dominated by the presence of laminin similar to Engelbreth-Holm-Swarm (EHS) tumour ECM. However, in contrast to EHS tumour ECM, another ECM component, entactin, was below the level of detection in trophoendodermal stem cell ECM. The laminins present in the two types of trophoendodermal stem cell transplants exhibited distinct differences. Tissues used as sources of one type of laminin were devoid of the other type of laminin. The two species of rat laminin behaved similarly on sodium dodecyl sulphate-polyacrylamide gels and had virtually identical amino acid compositions. The laminins also had similar cruciform patterns when examined by rotary shadowing. Rat laminins differed in their binding to an ion exchange resin: laminin isolated from peritoneal cysts bound to the resin (acidic laminin); laminin isolated from solid masses failed to bind (basic laminin). Acidic rat laminin showed reduced capacity to form laminin-laminin associations when compared with basic rat laminin. Acidic/soluble laminin proved to be a useful reagent in the development of a radio-immunoassay for laminin. Laminin concentrations in the peritoneal fluid of transplant-bearing rats was very high (approximately 400 micrograms/ml) and entirely of the acidic/soluble form. In summary, trophoendodermal stem cell ECM possesses a distinct composition with a lack of detectable entactin, and trophoendodermal stem cells are capable of modulating the characteristics of laminin, depending upon their organization. These features of trophoendodermal stem cell ECM may represent signals responsible for at least some of the unique features of the trophoendodermal stem cell transplants.

Expression of alkaline phosphatase in differentiated rat labyrinthine trophoblast tissue.

In this report, we describe the generation of specific antibodies to rat alkaline phosphatase and the temporal and regional characteristics of alkaline phosphatase expression during maturation of the rat chorioallantoic placenta. An antipeptide antiserum was generated to the amino terminal 15 amino acids of rat alkaline phosphatase. The antiserum specifically recognized alkaline phosphatase. Alkaline phosphatase expression was monitored in the junctional and labyrinth zones of the chorioallantoic placenta by Western and Northern blot analyses. Alkaline phosphatase protein and mRNA were present in both the junctional and labyrinth zones on day 13 of gestation. As gestation advanced, alkaline phosphatase mRNA and protein expression decreased below the limits of detection in the junctional zone, while alkaline phosphatase expression increased in the labyrinth zone. Labyrinthine alkaline phosphatase migrated predominantly as a 95-kDa species, whereas rat kidney expressed exclusively the 75-kDa species. Enzymatic deglycosylation of the 75- and 95-kDa alkaline phosphatase species resulted in the generation of a 55-kDa species. In summary, alkaline phosphatase expression is a useful indicator of trophoblast differentiation.