White Dot Syndromes: Report of Three Cases

Introduction

The term white dot syndromes has been used to refer conditions that differ in their morphology and prognosis. We report three cases of different pathologies encompassed within the white dot syndromes.

Case Presentations

Case 1: A 26-year-old female presented with scotoma in her right eye. Fundus examination revealed multiple white dots that demonstrated early hyperfluorescence with late staining on FA. OCT showed discontinuities in inner segment-outer segment junction associated with columnar-shaped outer retinal hyperreflective bands. AF revealed multiple hyperautofluorescent dots around the posterior pole, compatible with multiple evanescent white dot syndrome. The symptoms improved without treatment. Case 2: A 16-year-old male presented with retinal lesions compatible with punctate inner choroidopathy in his right eye. OCT showed lesion in the outer retinal layer. FAF revealed parafoveal hypoautofluorescent dots with early hyperfluorescence and late staining on FFA. After oral corticotherapy, they progress to atrophic scars. Case 3: A 65-year-old male presented with scotoma and decreased vision in his right eye. OCT showed hyperreflectivity in the outer layer that progresses to a large atrophic plaque with foveal affectation. FAF demonstrated hyperautofluorescent placoid lesion occupying macular area, compatible with acute posterior multifocal placoid pigment epitheliopathy. Retinal lesions improved with systemic corticosteroids.

Conclusion

The FAF pattern helps know the distribution of the lesions. It represents a noninvasive method that has been shown to be useful in the diagnosis and monitoring of white dot syndromes.

[Age does not affect the outcome of allogeneic hematopoietic precursor transplantation for acute myeloid leukemia]

BACKGROUND

In our country, transplantation centers differ in the age limit for allogeneic hematopoietic transplantation (ALOHT). In our program, transplants with age- adjusted conditioning are performed in patients until 70 years old. Currently more than 60% of ALOHT reported to the Center for International Bone Marrow Transplantation Research (CIBMTR) are performed in patients older than 40 years.

AIM

To report our experience with ALOHT in acute myelogenous leukemia (AML), analyzing patient age at transplantation in different periods and transplant results in different age groups.

MATERIAL AND METHODS

A retrospective analysis of the database of adult hematopoietic transplants in AML patients was performed. Demographic data, disease characteristics, transplant data, survival and relapse times, and mortality were collected.

RESULTS

In our program, 1030 transplants were performed in adults and 119 ALOHT were performed in AML patients, between 1990 and 2020. The median age of patients in all periods was 41 years, (range 16-69). The median age was 33 and 45 years, in the periods 1990-2000 and 2000-2020 respectively (p < 0.01). Seventy-eight patients received myeloablative conditioning (median age 44 years) and 41 reduced intensity conditioning (median age 53 years). Five-year overall survival was 44.6% (confidence intervals (CI) 41-48). Non relapse mortality of all periods was 19% (CI 17 - 40%) and relapse rate was 17 % (CI 16-22). No difference in five years overall survival among patients younger than 40, 41 to 50 and over 51 years was observed.

CONCLUSIONS

Overall Survival, non-relapse mortality and relapse rate were similar in younger and older patients in our program and similar to those previously reported in other centers.

H2A.Z overexpression suppresses senescence and chemosensitivity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most intractable and devastating malignant tumors. Epigenetic modifications such as DNA methylation and histone modification regulate tumor initiation and progression. However, the contribution of histone variants in PDAC is unknown. Here, we demonstrated that the histone variant H2A.Z is highly expressed in PDAC cell lines and PDAC patients and that its overexpression correlates with poor prognosis. Moreover, all three H2A.Z isoforms (H2A.Z.1, H2A.Z.2.1, and H2A.Z.2.2) are highly expressed in PDAC cell lines and PDAC patients. Knockdown of these H2A.Z isoforms in PDAC cell lines induces a senescent phenotype, cell cycle arrest in phase G2/M, increased expression of cyclin-dependent kinase inhibitor CDKN2A/p16, SA-β-galactosidase activity and interleukin 8 production. Transcriptome analysis of H2A.Z-depleted PDAC cells showed altered gene expression in fatty acid biosynthesis pathways and those that regulate cell cycle and DNA damage repair. Importantly, depletion of H2A.Z isoforms reduces the tumor size in a mouse xenograft model in vivo and sensitizes PDAC cells to gemcitabine. Overexpression of H2A.Z.1 and H2A.Z.2.1 more than H2A.Z.2.2 partially restores the oncogenic phenotype. Therefore, our data suggest that overexpression of H2A.Z isoforms enables cells to overcome the oncoprotective barrier associated with senescence, favoring PDAC tumor grow and chemoresistance. These results make H2A.Z a potential candidate as a diagnostic biomarker and therapeutic target for PDAC.

Effectiveness of nurse-led hospital-based heart failure programmes in octagenarians and nonagenarians: is age important?

Background

Efficacy of HF programmes in oldest old (octogenarians and nonagenarians) has not been fully explored.

Methods

We conducted a natural experiment evaluating all patients after hospitalization for heart failure as primary diagnosis between January 2017 and January 2019. We compared outcomes between patients discharged during Period #1, before the implementation of the program with patients discharged during Period #2, after the implementation of the 7-step bundle of interventions. We explored the interaction between age group (&lt;80 vs. ≥80 years old) by the intervention modality (HF programme vs. usual care). Primary end-point was the combined end-point of all-cause death or all-cause hospitalization at 6 months after discharge from the index hospitalization.

Results

The study enroled 440 patients. Mean age of the whole cohort was 75±9 years. In the oldest old subgroup (n=160), mean age was 84±3. No differences were found in baseline characteristics of patients between usual care and HF program. 30-day all-cause readmission was significantly reduced in patients in the HF programme group compared to patients in the usual care group in both age strata. In unadjusted Cox regression analyses in the oldest old group, management of patients in the HF programme was significanty associated with a reduction in the risk of the primary end-point (HR: 0.50; 95% CI [0.29–0.85]; p=0.011).

Conclusions

Management of patients in a nurse-led integrated care-based heart failure programme results in reduction of all-cause death or all-cause hospitalizations in oldest old patients.

Event-free survival cumulative curves.

Funding Acknowledgement

Type of funding source: None

Controlled grafting of dialkylphosphonate-based ionic liquids on γ-alumina: design of hybrid materials with high potential for CO2 separation applications

In this work we provide a detailed study on grafting reactions of various dialkylphosphonate-based ILs. Special attention has been devoted to a comprehensive investigation on how the nature of the anion and the organic spacer composition (hydrophilic or hydrophobic groups) could impact the grafting densities and bonding modes of phosphonate-based ILs anchored to γ-alumina (γ-Al₂O₃) powders. For the first time, the bonding of phosphonate-based ILs with only surface hexacoordinated aluminum nuclei was established using both solid-state ³¹P–²⁷Al D-HMQC and ³¹P NMR experiments. It has been demonstrated that the grafting of dialkylphosphonate-based ILs is competing with a hydrolysis and/or precipitation process which could be attractively hindered by changing the anion nature: bis(trifluoromethane)sulfonylimide anion instead of bromide. In additon, independently of the chosen spacer, similar reaction conditions led to equivalent grafting densities with different bonding mode configurations. The CO₂ physisorption analysis on both pure ILs and grafted ILs on alumina powders confirmed that the initial sorption properties of ILs do not change upon grafting, thus confirming the attractive potential of as-grafted ILs for the preparation of hybrid materials in a form of selective adsorbers or membranes for CO₂ separation applications.

Grafting of diethylphophonate-based ILs onto γ-Al₂O₃ powder in solvothermal condition was achieved on mesoporous γ-alumina powder and membrane (A = organic spacer).

Severe acute respiratory infections (SARI) from influenza in adult patients in Chile: the experience of a sentinel hospital

Objective

To 1) describe clinical characteristics of adult patients in Chile with severe acute respiratory infections (SARI) associated with influenza viruses, and 2) analyze virus subtypes identified in specimens collected from those patients, hospital resources used in clinical management, clinical evolution, and risk factors associated with a fatal outcome, using observational data from the SARI surveillance network (SARInet).

Methods

Adults hospitalized from 1 July 2011 to 31 December 2015 with influenza-associated SARI at a SARI sentinel surveillance hospital in Santiago were identified and the presence of influenza in all cases confirmed by reverse transcription polymerase chain reaction (RT-PCR), using respiratory samples.

Results

A total of 221 patients (mean age: 74.1 years) were hospitalized with influenza-associated SARI during the study period. Of this study cohort, 91.4% had risk factors for complications and 34.3% had been vaccinated during the most recent campaign. Pneumonia was the most frequent clinical manifestation, occurring in 57.0% of the cohort; other manifestations included influenza-like illness, exacerbated chronic bronchitis, decompensated heart failure, and asthmatic crisis. Cases occurred year-round, with an epidemic peak during autumn–winter. Both influenza A (H1N1pdm09 and H3N2) and B virus co-circulated. Critical care beds were required for 26.7% of the cohort, and 19.5% needed ventilatory assistance. Multivariate analysis identified four significant factors associated with in-hospital mortality: 1) being bedridden (adjusted odds ratio (aOR): 22.3; 95% confidence interval (CI): 3.0–164); 2) admission to critical care unit (aOR: 8.9; CI: 1.44–55); 3) Pa0₂/Fi0₂ ratio < 250 (aOR: 5.8; CI: 1.02–33); and 4) increased serum creatinine concentration (> 1 mg/dL) (aOR: 5.47; CI: 1.20–24). Seasonal influenza vaccine was identified as a significant protective factor (aOR: 0.14; CI: 0.021–0.90).

Conclusions

Influenza-associated SARI affected mainly elderly patients with underlying conditions. Most patients evolved to respiratory failure and more than one-quarter required critical care beds. Clinical presentation was variable. Death was associated with host characteristics and disease-associated conditions, and vaccine was protective. Virus type did not influence outcome.

Prediction of Neurocognitive Deficits by Parkinsonian Motor Impairment in Schizophrenia: A Study in Neuroleptic-Naïve Subjects, Unaffected First-Degree Relatives and Healthy Controls From an Indigenous Population

BACKGROUND

Neurocognitive deficits are among the most debilitating and pervasive symptoms of schizophrenia, and are present also in unaffected first-degree relatives. Also, multiple reports reveal parkisonian motor deficits in untreated subjects with schizophrenia and in first-degree relatives of affected subjects. Yet, the relation between motor and cognitive impairment and its value as a classifier of endophenotypes has not been studied.

AIMS

To test the efficacy of midbrain hyperechogenicity (MHE) and parkinsonian motor impairment (PKM) as predictors of neurocognitive impairment in subjects with or at risk for schizophrenia, that could be used to segregate them from first-degree relatives and healthy controls.

METHOD

Seventy-six subjects with chronic schizophrenia never exposed to antipsychotic medication, 106 unaffected first-degree relatives, and 62 healthy controls were blindly assessed for cognitive and motor function, and transcranial ultrasound.

RESULTS

Executive function, fluid intelligence, motor planning, and hand coordination showed group differences. PKM and MHE were significantly higher in untreated schizophrenia and unaffected relatives. Unaffected relatives showed milder impairment, but were different from controls.

CONCLUSIONS

PKM and MHE predict cognitive impairment in neuroleptic-naive patients with schizophrenia and their unaffected first-degree relatives and may be used to segregate them from first-degree relatives and healthy controls.

Detection, Assessment, and Management of Schizophrenia in an Andean Population of South America: Parkinsonism Testing and Transcranial Ultrasound as Preventive Tools

Schizophrenia is a debilitating psychiatric illness that is among the world's top 10 causes of long-term disability, affecting people who are just entering the peak of social, economic, and intellectual productivity. Such functional loss is particularly relevant in indigenous communities, which rely on change in functional status (rather than on the presence of symptoms) to identify mental illness. Particularly among the indigenous communities of Latin America, the gap between mental health need and availability of resources to reduce the burden has been judged "a case of outrageous exclusion." For more than a decade, as part of the Investigation of Movement Abnormalities and Genetic of Schizophrenia study, the authors have been studying vulnerability markers (genetic, motor, imaging, and neuropsychological differences) for schizophrenia in a remote, indigenous population in rural northern Argentina. In this article, the authors discuss the implementation of a task-shifting paradigm resulting in more proficient identification and referral of individuals with untreated psychosis and a severalfold reduction in the duration of untreated psychosis, with very high retention rates (70%) and treatment adherence during a decade in a rural environment. The authors also propose to use transcranial ultrasound screening and testing for parkinsonism at illness onset before introduction of neuroleptics as potentially useful markers in determining illness severity, negative symptomatology, and tolerance to antipsychotic treatment/refractoriness.

Sex and laterality differences in parkinsonian impairment and transcranial ultrasound in never-treated schizophrenics and their first degree relatives in an Andean population

We tested the hypothesis that loss of substantia nigra neurons in subjects at risk of schizophrenia (1), as reflected by midbrain hyperechogenicity (2) and parkinsonian motor impairment (3), is asymmetric and influenced by sex. We evaluated 62 subjects with never-treated chronic schizophrenia, 80 of their adult, unaffected first degree relatives and 62 healthy controls (matched by sex and age to the cases), part of an Andean population of Northern Argentina. Parkinsonism was scored blindly using UPDRS-3 (Unified Parkinson's Disease Rating Scale) on videotaped exams by 2 independent raters. Transcranial ultrasound was performed by an expert sonographist blind to subject condition with a 2.5 MHz transducer through a temporal bone window. Quantification of echogenic area was carried out on saved images by a different evaluator. We found a significant difference in parkinsonian motor impairment between patients, their relatives as well as controls. All three groups showed worse parkinsonism on the left side than the right, corresponding with increased echogenicity on the right substantia nigra compared with the left. Females had significantly more right echogenicity than males, and patients and unaffected relatives were significantly more echogenic than controls on that side. On the left, only female patients had significant echogenicity. Our data supports the notion that unaffected relatives of schizophrenic subjects have increased parkinsonism and concomitant brainstem abnormalities which may represent a vulnerability to the disease. Both motor and brainstem abnormalities are asymmetric and influenced by sex.

BMP signaling and microtubule organization regulate synaptic strength

The strength of synaptic transmission between a neuron and multiple postsynaptic partners can vary considerably. We have studied synaptic heterogeneity using the glutamatergic Drosophila neuromuscular junction (NMJ), which contains multiple synaptic connections of varying strengths between a motor axon and muscle fiber. In larval NMJs, there is a gradient of synaptic transmission from weak proximal to strong distal boutons. We imaged synaptic transmission with the postsynaptically targeted fluorescent calcium sensor SynapCam, to investigate the molecular pathways that determine synaptic strength and set up this gradient. We discovered that mutations in the Bone Morphogenetic Protein (BMP) signaling pathway disrupt production of strong distal boutons. We find that strong connections contain unbundled microtubules in the boutons, suggesting a role for microtubule organization in transmission strength. The spastin mutation, which disorganizes microtubules, disrupted the transmission gradient, supporting this interpretation. We propose that the BMP pathway, shown previously to function in the homeostatic regulation of synaptic growth, also boosts synaptic transmission in a spatially selective manner that depends on the microtubule system.

The efficacy of targeted health agents education to reduce the duration of untreated psychosis in a rural population

The duration of untreated psychosis (DUP) is a key determinant in the severity of symptoms in patients with schizophrenia. DUP is a modifiable factor that if reduced can improve patient outcome and treatment response. We sought to decrease DUP in rural Argentina by instituting annual training of local health agents to better identify signs of mental illness and offer earlier intervention. DUP was estimated using Schedules of Clinical Assessment in Neuropsychiatry (SCAN). Ongoing training was correlated with a reduction in DUP. Reducing DUP through better screening can decrease the psychosocial burden of disease and improve the trajectory of psychosis.

Normal "high" thyroid stimulating hormone (TSH) levels and pregnancy rates in patients undergoing IVF with donor eggs

OBJECTIVE

To determine if a relationship exists between pregnancy rates obtained in patients undergoing in vitro fertilization (lVF) with donor eggs and levels of thyroid stimulating hormone greater than 2.5 mlU/L but still within a range considered normal.

STUDY DESIGN

Retrospective comparative cohort study. With prior approval of the Ethics Committee, 233 patients undergoing IVF with donor eggs, in a two-year period, were included. Patients were grouped depending on the thyroid stimulating hormone (TSH) level. Pregnancy rates were compared. Statistical analysis was made with the Chi-square test.

RESULTS

Pregnancy rates, depending on the TSH level, were 56.6% in patients with TSH levels below 2.49 mU/L vs. 21.6%, in patients with levels above 2.5 mU/L. This difference was statistically significant (p < 0.001).

CONCLUSIONS

Mild abnormalities of thyroid function may adversely affect the pregnancy rates in patients un- dergoing in vitro fertilization with donor eggs. A possible alteration in endometrial function may be associated.

Bipolar disorders and affective temperaments: a national family study testing the "endophenotype" and "subaffective" theses using the TEMPS-A Buenos Aires

BACKGROUND

The purpose of this study is to examine the prevalence of affective temperaments between clinically unaffected relatives of bipolar patients and secondarily to investigate the impact of these "subaffective" forms on their quality of life (QoL).

METHODS

The study was performed in seven sites across Argentina. We administered the scales TEMPS-A and Quality of Life Index to a sample of 114 non-ill first degree relatives of bipolar disorder patients ("cases") and 115 comparison subjects without family history of affective illness ("controls"). We used The Mood Disorder Questionnaire to rule out clinical bipolarity.

RESULTS

Mean scores on all TEMPS-A subscales were significantly higher in cases, except for hyperthymia. The prevalence of affective temperaments, according to Argentinean cut-off points, was also higher, with statistical significance for cyclothymic and anxious temperaments. Regarding QoL, we found no significant differences between both groups, except for interpersonal functioning, which was better in controls. A detailed subanalysis showed significant effects of QoL domains for all temperaments, except for the hyperthymic.

LIMITATIONS

We used self-report measures. A larger sample size would have provided us greater statistical power for certain analyses.

CONCLUSIONS

Our findings support the concept of a spectrum of subthreshold affective traits or temperaments - especially for the cyclothymic and anxious - in bipolar pedigrees. We further demonstrated that, except for the hyperthymic, quality of life was affected by these temperaments in "clinically well" relatives. Overall, our data are compatible with the "endophenotype" and "subaffective" theses for affective temperaments.

First principles NMR calculations of phenylphosphinic acid C6H5HPO(OH): assignments, orientation of tensors by local field experiments and effect of molecular motion

The complete set of NMR parameters for (17)O enriched phenylphosphinic acid C(6)H(5)HP( *)O(*OH) is calculated from first principles by using the Gauge Including Projected Augmented Wave (GIPAW) approach [C.J. Pickard, F. Mauri, All-electron magnetic response with pseudopotentials: NMR chemical shifts, Phys. Rev. B 63 (2001) 245101/1-245101/13]. The analysis goes beyond the successful assignment of the spectra for all nuclei ((1)H, (13)C, (17)O, (31)P), as: (i) the (1)H CSA (chemical shift anisotropy) tensors (magnitude and orientation) have been interpreted in terms of H bonding and internuclear distances. (ii) CSA/dipolar local field correlation experiments have allowed the orientation of the direct P-H bond direction in the (31)P CSA tensor to be determined. Experimental and calculated data were compared. (iii) The overestimation of the calculated (31)P CSA has been explained by local molecular reorientation and confirmed by low temperature static (1)H-->(31)P CP experiments.

A simple method for the construction of small format tissue arrays

Tissue arrays can evaluate molecular targets in high numbers of samples in parallel. Array construction presents technical difficulties and tissue arrayers are expensive, particularly for small and medium sized laboratories. This report describes a method for the construction of 36 sample arrays using widely available materials. A blunted 16 gauge needle for bone marrow aspiration was used to extract paraffin wax cylinders and manually define a 6 x 6 matrix on a blank paraffin wax block. Tissue cores from 36 paraffin wax embedded premalignant lesions and invasive cervical carcinomas were injected into the matrix using a 14 gauge needle. This tissue array was sectioned using a standard microtome and used for the immunodetection of CD44 variant 9 and interleukin 18 with satisfactory results. This method can be applied in any laboratory, without the need of specialised equipment, offering a good alternative for the wider application of tissue arrays.

Genetically encoded optical sensors of neuronal activity and cellular function

Fluorescent proteins (FPs) have been engineered to produce an optical report in response to cellular signals. FP fluorescence can be made directly sensitive to the chemical environment, via specific mutations of or around the chromophore. Alternatively, FPs can be made indirectly sensitive to cellular signals by their fusion to 'detector' proteins that respond to specific cellular signals with structural rearrangements that act on the FP to alter fluorescence. These optical sensors of membrane voltage, neurotransmitter release, and intracellular messengers, including powerful new sensors of Ca(2+), cyclic nucleotides and nitric oxide, are likely to provide new insights into the workings of cellular signals and of information processing in neural circuits.

A ryanodine fluorescent derivative reveals the presence of high-affinity ryanodine binding sites in the Golgi complex of rat sympathetic neurons, with possible functional roles in intracellular Ca(2+) signaling

The plant alkaloid ryanodine (Ry) is a high-affinity modulator of ryanodine receptor (RyR) Ca(2+) release channels. Although these channels are present in a variety of cell types, their functional role in nerve cells is still puzzling. Here, a monosubstituted fluorescent Ry analogue, B-FL-X Ry, was used to reveal the distribution of RyRs in cultured rat sympathetic neurons. B-FL-X Ry competitively inhibited the binding of [3H]Ry to rabbit skeletal muscle SR membranes, with an IC(50) of 150 nM, compared to 7 nM of unlabeled Ry. Binding of B-FL-X Ry to the cytoplasm of sympathetic neurons is saturable, reversible and of high affinity. The pharmacology of B-FL-X Ry showed marked differences with unlabeled Ry, which are partially explained by its lower affinity: (1) use-dependent reversible inhibition of caffeine-induced intracellular Ca(2+) release; (2) diminished voltage-gated Ca(2+) influx, due to a positive shift in the activation of voltage gated Ca(2+) currents. B-FL-X Ry-stained sympathetic neurons, viewed under confocal microscopy, showed conspicuous labeling of crescent-shaped structures pertaining to the Golgi complex, a conclusion supported by experiments showing co-localization with Golgi-specific fluorescent probes and the breaking up of crescent-shaped staining after treatment with drugs that disassemble Golgi complex. The presence of RyRs to the Golgi could be confirmed with specific anti-RyR(2) antibodies, but evidence of caffeine-induced Ca(2+) release from this organelle could not be obtained using fast confocal microscopy. Rather, an apparent decrease of the cytosolic Ca(2+) signal was detected close to this organelle. In spite of that, short-term incubation with brefeldin A (BFA) suppressed the fast component of caffeine-induced Ca(2+) release, and the Ca(2+) release process lasted longer and appeared less organized. These observations, which suggest a possible role of the Golgi complex in Ca(2+) homeostasis and signaling in nerve cells, could be relevant to reports involving derangement of the Golgi complex as a probable cause of some forms of progressive neuronal degeneration, such as Alzheimer's disease and amyotrophic lateral sclerosis.

Chlorogenic acids as a potential criterion in coffee genotype selections

A systematic study by HPLC was conducted to determine the content of chlorogenic acids in green coffee beans of the Variedad Colombia (Coffea arabica Caturra var. x Híbrido de Timor) and in other genotypes of interest of C. arabica, Coffea canephora, Híbrido de Timor, and the F1 offspring derived from the crossing Caturra x Híbrido de Timor. Comparisons were made of the total content of these acids, their quantitative differences, and the presence or absence of some of them, using parametric statistical techniques and multivariate analysis. Total content differences were found between C. canephora accessions, between Típica and Caturra varieties of C. arabica, and between Híbrido de Timor accessions. The chromatographic profile comparisons with principal component analysis separated in the first component C. canephora accessions from the rest of the genotypes, whereas the second component separated C. canephora accessions.

Syntheses, characterizations, and single-crystal X-ray structures of soluble titanium alkoxide phosphonates

Reactions of Ti(OiPr)4 with different phosphonic acids RPO3H2 (R = Ph, 4-CNPh, Me, tBu) in organic solvents have been investigated. In the presence of small amounts of water, the new molecular titanium oxide alkoxide phosphonates [Ti4(mu 3-O)(OiPr)5(mu-OiPr)3(RPO3)3].DMSO [R = Ph (1), Me (2), tBu (3), 4-CNPh (4)] were isolated. The single-crystal X-ray structure analyses of 1 and 2 revealed hexacoordinated titanium atoms and a connectivity of (111) for each phosphonate. Under rigorous exclusion of water, the reaction of Ti(OiPr)4 with tert-butylphosphonic acid in toluene gave the titanium phosphonate tetramer [Ti(OiPr)2(tBuPO3)]4 (5). A single-crystal X-ray structure analysis of 5 revealed a 5 + 1 coordination of the titanium atoms as a result of the (112) connectivity of each phosphonate; such a coordination mode has never been reported for a titanium phosphate, phosphonate, or phosphinate. Compounds 1-5 were characterized by FT-IR, 31P MAS NMR, and solution multinuclear NMR (1H, 13C(1H,) 31P(1H)) spectroscopies. 13C CP MAS NMR experiments were carried out on arylphosphonates 1 and 4. Solution NMR experiments were also used to investigate the exchange reaction between 1 and 2 and the conversion of 5 to [Ti4(mu 3-O)(OiPr)5(mu-OiPr)3(tBuPO3)3].iPrOH by partial hydrolysis in the presence of Ti(OiPr)4. The phosphonate clusters 1-5 are soluble in organic solvents and are likely intermediates in the sol-gel processing of inorganic-organic hybrids based on titanium oxide and phosphonate groups that we are currently developing.

Ectopic expression of luteinizing hormone-releasing hormone and peripherin in the respiratory epithelium of mice lacking transcription factor AP-2alpha

The vertebrate transcription factor activator protein-2 (AP-2alpha) is involved in craniofacial morphogenesis. In the nasal placode AP-2alpha expression delineates presumptive respiratory epithelia from olfactory epithelia, with AP-2alpha expression restricted to the anterior region of the respiratory epithelium (absent from the olfactory epithelium) at later stages. To address the role AP-2alpha plays in differentiation of cell groups in the nasal placode, the spatiotemporal expression pattern of four markers normally associated with olfactory epithelial structures was analyzed in mice lacking AP-2alpha. These markers were the intermediate filament protein peripherin, the neuropeptide luteinizing hormone-releasing hormone (LHRH), the neural cell adhesion molecule (NCAM) and the olfactory transcription factor Olf-1. Development of cells expressing these markers was similar in both genotypes until embryonic day 12.5 (E12.5), indicating that the main olfactory epithelium and olfactory pit formation was normal. At E13.5 in mutant mice, ectopic LHRH neurons and peripherin axons were detected in respiratory epithelial areas, areas devoid of Olf-1 and NCAM staining. Over the next few days, an increase in total nasal LHRH neurons occurred. The increase in nasal LHRH neurons could be accounted for by LHRH neurons arising and migrating out of respiratory epithelial regions on peripherin-positive fibers. These results indicate that AP-2alpha is not essential for the separation of the olfactory and respiratory epithelium from the nasal placode and is consistent with AP-2alpha preventing recapitulation of developmental programs within the respiratory epithelium that lead to expression of LHRH and peripherin phenotypes.

[Osteoporosis in Mexican postmenopausal women. Magnitude of the problem. Multicenter study]

Incidencia of osteoporosis induced fractures increases with age; risk increases exponentially as bone mass decreases. Women are prone to osteoporosis 2 to 3 times more than men, due to lower "peak" bone mass and the accelerated loss that occurs after the menopause. The prevalence of osteoporosis in with Caucasian postmenopausal women varies from 16 to 30% depending upon the number of sites measured (lumbar spine/hip and/or forearm). The aim of this study was to estimate the prevalence of osteopenia and osteoporosis in pre and postmenopausal Mexican women in relation to men, and to that reported in Caucasia women. The study involved 4,821 apparently healthy subjects (without known risk factors for osteoporosis), 4,467 females and 354 males from 11 different centers of Mexican Republic, 20 to 90 years old, using DXA bone densitometry of lumbar spine and hip. Prevalence of osteoporosis in women is twice that in men (P < 0.001), and it increases with age, particularly after the menopause (P < 0.0001). Our study found a prevalence of osteoporosis of the lumbar spine and/or hip in apparently healthy postmenopausal Mexican women over 50 years of age of 16%, increasing to 20% in those women with or without risk factors who attended voluntarily or by suggestion of their physician to be studied. The prevalence values obtained seem to be lower than those reported for Caucasian women, 30%. We found a prevalence of osteoporosis of 16% and of osteopenia of 57% in women 50 years of age and older. We also found a higher prevalence of osteoporosis in women of the south east part of the county.

Mutagenesis disrupts posttranslational processing of the Na,K-ATPase catalytic subunit

The first 5 amino acids of the catalytic alpha 1 isoform from Na,K-ATPase are cleaved enzymatically during or after translation. To evaluate the structural requirements for that cleavage, we constructed amino-terminal mutants of alpha 1 in which an epitope tag from the c-myc oncogene product was added. Immunoblots of isolated membranes from transfected monkey kidney cells revealed binding of an antibody specific for the first 9 residues of the alpha 1 nascent protein. Because this antibody does not recognize the shorter sequence corresponding to the processed polypeptide, these results indicate that the epitope tag prevented normal processing, a conclusion confirmed by the observed binding of an anti-myc antibody. In contrast, membranes from cells expressing deletion mutants that lack residues 10-24 and 10-31 of the nascent chain failed to bind the amino-terminal-directed antibody, suggesting that the mutants were cleaved normally and that amino acids downstream of the first 9 are not required for proteolysis. Amino-terminal mutants produced in other laboratories have shown an anomalous stimulation of ATPase activity by K+ when measured in low ATP concentrations. The myc-tagged and downstream deletion mutants were sensitive to K+ in the range from 0.05 to 5 mM, similar to wild-type enzyme, despite the differences in posttranslational processing. A mutant missing the first 40 residues of the nascent chain, however, displayed an activation by K+. These results suggest that amino-terminal processing of the alpha 1 isoform was prevented by mutation, yet that processing had little influence on the kinetic parameter most likely to be influenced by such changes.

Nucleotides in embryos in the stages of morula, gastrula, and neurula

Levels of nucleotides and sugar nucleotides in embryos of Bufo arenarum at the stages of morula, gastrula, and neurula have been measured. The total amounts of purine nucleoside diphosphates decreased from morula to gastrula, but increased sharply from gastrula to neurula. The levels of ADP followed this pattern, but those of GDP did not change significantly through the three stages. Purine nucleoside triphosphate levels, which had increased immediately after fertilization, remained almost constant through morula, gastrula, and neurula. As with the purine nucleoside diphosphates, the adenine nucleotide decreased from morula to gastrula, and increased from gastrula to neurula. In contrast, the level of GTP showed a sharp maximum at gastrula. The total pyrimidine nucleoside triphosphate did not change significantly from morula through neurula. As in previous stages of development, only uridine sugar nucleotides were detected. A sharp increase of the galactosyl ester of nucleotides was found at gastrula.