Trophic Path of Marked Exuviae Within Colonies of Coptotermes gestroi (Blattodea: Rhinotermitidae).

Nitrogen, a limiting growth factor in wood-feeding insects, was hypothesized to play a role in the recently discovered behavior of subterranean termites returning to the nest to molt. Coptotermes gestroi (Wasmann) exuviae is approximately 11% N by dry weight, and therefore a potentially rich source of recyclable nitrogen. Exuviae from a C. gestroi colony were marked with immunoglobulin G (IgG) and were fed to two-year-old C. gestroi colonies. IgG-marked exuviae were detected with an enzyme-linked immunosorbent assay. The IgG marker was later detected in every caste and life stage except first-instar larvae (L1). The proportion of individuals positive for the marker varied by caste, with the queens always being positive for the marker. The queens and second-or-higher-instar workers (W2+) had significantly higher concentrations of the marker than the eggs and L1. The trophic path of exuviae includes individuals that directly fed on marked exuviae (workers and possibly second-instar larvae) and individuals that secondarily received marked exuviae through trophallaxis (queens, kings, and soldiers). This study described the trophic path of consumed exuviae and demonstrated its role in the recycling of nitrogen in a subterranean termite. Molting at the central nest may be an efficient means to transfer nitrogen from shed exuviae to recipients and may be a nitrogen recycling behavior conserved from a termite ancestor.

Exuviae Recycling Can Enhance Queen Oviposition and Colony Growth in Subterranean Termites (Blattodea: Rhinotermitidae: Coptotermes).

Wood-feeding termites have a nitrogen-poor diet and have therefore evolved nitrogen conservation strategies. However, termite workers molt periodically, and throughout the lifetime of a colony, millions of exuviae, a nitrogen-rich resource, are produced by the colony. In Coptotermes Wasmann, workers foraging at remote feeding sites must return to the central part of the nest to molt, where the queen, king, eggs, and larvae are located. It was hypothesized that this molting-site fidelity is an efficient way to recycle nitrogen for reproduction and colony growth, as nestmates involved in exuviae consumption can directly transfer such resources to individuals engaged in reproduction (the queen) or growth (larvae). This study investigates whether incipient colonies of C. gestroi (Wasmann) can gain additional biomass when they are fed supplementary exuviae. Incipient colonies were reared in nitrogen-poor or nitrogen-rich conditions, and 0, 1, 5, or 10 exuviae were added to 3-month-old colonies. After 6.5 months, colonies reared in nitrogen-poor environments gained significantly more biomass when exuviae were added than colonies with no added exuviae. However, the addition of exuviae had no effect on colony growth for colonies reared in nitrogen-rich environments. In a second experiment, queens from colonies in which exuviae were effectively removed laid fewer eggs than queens from colonies in which exuviae were not removed. Therefore, consumption of exuviae from molting individuals by nestmates is an important part of the nitrogen recycling strategy in Coptotermes colonies, as it facilitates queen oviposition and colony growth, especially when such colonies have limited access to nitrogen-rich soils.

Methoprene-Induced Genes in Workers of Formosan Subterranean Termites (Coptotermes formosanus Shiraki).

Termites have a distinct polyphenism controlled by concise hormonal and molecular mechanisms. Workers undergo double molts to transform into soldiers (worker-presoldier-soldier). Juvenile hormone analogs, such as methoprene, can induce workers to transform into presoldiers. However, the molecular mechanism underlying the worker-to-presoldier transformation in Coptotermes formosanus Shiraki is still not clear. We sequenced the transcriptome of workers four days after they had fed on methoprene-treated filter paper and control group workers, which fed on acetone-treated filter paper. The transcriptome of C. formosanus was assembled using the de novo assembly method. Expression levels of unigenes in the methoprene-treated group and the control group were compared. The differentially expressed genes were further analyzed by Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Tetrapyrrole binding, oxidoreductase activity, and metal ion binding were the only three enriched GO terms. Juvenile hormone synthesis was the first ranked enriched pathway. Carbohydrate, amino acid, and lipid metabolism pathways were also enriched. These three pathways may be related to fat body development, which is critical for presoldier formation. Our results have demonstrated the significance of JH synthesis pathways, and pathways related to fat body development in the artificial induction of presoldiers.

A cellular and molecular basis for the selective desmopressin-induced ACTH release in Cushing disease patients: key role of AVPR1b receptor and potential therapeutic implications.

CONTEXT: Desmopressin is a synthetic agonist of vasopressin receptors (AVPRs). The desmopressin stimulation test is used in the diagnosis and postsurgery prognosis of Cushing disease (CD). However, the cellular and molecular mechanisms underlying the desmopressin-induced ACTH increase in patients with CD are poorly understood. OBJECTIVE: The objectives of this study were to determine, for the first time, whether desmopressin acts directly and exclusively on pituitary corticotropinoma cells to stimulate ACTH expression/release and to elucidate the cellular and molecular mechanisms involved in desmopressin-induced ACTH increase in CD. DESIGN: A total of 8 normal pituitaries (NPs), 23 corticotropinomas, 14 nonfunctioning pituitary adenomas, 17 somatotropinomas, and 3 prolactinomas were analyzed for AVPR expression by quantitative real-time RT-PCR. Primary cultures derived from corticotropinomas, nonfunctioning pituitary adenomas, somatotropinomas, prolactinomas, and NPs were treated with desmopressin, and ACTH secretion/expression, [Ca(2+)]i kinetics, and AVPR expression and/or proliferative response were evaluated. The relationship between AVPR expression and plasma adrenocorticotropin/cortisol levels obtained from desmopressin tests was assessed. RESULTS: Desmopressin affects all functional parameters evaluated in corticotropinoma cells but not in NPs or other pituitary adenomas cells. These effects might be due to the dramatic elevation of AVPR1b expression levels found in corticotropinomas. In line with this notion, the use of an AVPR1b antagonist completely blocked desmopressin stimulatory effects. Remarkably, only AVPR1b expression was positively correlated with elevated plasma adrenocorticotropin levels in corticotropinomas. CONCLUSIONS: The present results provide a cellular and molecular basis to support the desmopressin stimulation test as a reliable, specific test for the diagnosis and postsurgery prognosis of CD. Furthermore, our data indicate that AVPR1b is responsible for the direct/exclusive desmopressin stimulatory pituitary effects observed in CD, thus opening the possibility of exploring AVPR1b antagonists as potential therapeutic tools for CD treatment.

[Postsurgical meningitis. Differential characteristics of aseptic postsurgical meningitis]. / Meningitis postquirúrgica. Características diferenciales de la meningitis aséptica post-quirúrgica.

BACKGROUND: Postsurgical meningitis is a rare complication that is accompanied by an increase of hospital stay and high mortality. Some of these cases are not due to a true infection but due to an aseptic inflammation of the meninges denominated aseptic postsurgical meningitis (APSM). Proper identification of these cases would allow better use of antimicrobial drugs. METHODS: A retrospective study of patients with postsurgical meningitis in a universitary hospital for 14 years. We describe the clinical characteristics of patients with postsurgical bacterial meningitis (PBM) compared to those of patients with APSM. RESULTS: During the studied period 35 patients (71%) with PBM and 14 patients (29%) with (APSM) were identified. The mean age of patients with PBM was similar to that of patients with APSM. There was a male predominance in the group of PBM (71%) compared with patients with APSM (36%, p = 0.020). Patients with intracranial hemorrhage tended to present more cases of APSM (64%) than of PBM (34%, p = 0.055). Patients undergoing posterior fossa craniotomy (p = 0.092) and those receiving steroids (p = 0.051) showed a greater tendency to suffer APSM. It was also noted a trend towards present PBM in patients who had suffered an infection in the previous month (p = 0.072). There were seven patients with PBM (20%) with a cell count above 5000 cells/mm3 in CSF, values not found in any patients with APSM. No differences were detected in the glycorrachia and proteinorrachia between the two groups. The most common bacteria isolated were coagulase negative Staphylococcus and S. aureus. In 5 patients (14%) non fermenting gram-negative bacillus (Pseudomonas aeruginosa and Acinetobacter spp) were isolated. There were no deaths attributed to any type of postsurgical meningitis. CONCLUSION: Patients admitted for brain haemorrhage, undergoing posterior fossa surgery or receiving steroids tend to develop APSM. A CSF cell count above 5000 cells / mm3 strongly suggests MBP.

Modeling the healthcare assistance process for comorbidity patients compliant with prEN12967.

The increment of life expectancy in our society, and the consequent population ageing, anticipate that the health sector must face the challenges associated with a growing population group of elderly patients with numerous disorders, generally chronic. In this work we introduce a framework to support the communication and information management tasks involved in a coordinated care of this kind of patients. This framework has been developed in the European context, it is compliant with CEN's prEN12967, and follows ITU-T's ODP methodology, that facilitates its integration in any system following this standard.

[Role of allopurinol and rofecoxib in agranulocytosis and acute tubular necrosis]. / Implicación de alopurinol y rofecoxib en agranulocitosis y necrosis tubular aguda.

OBJECTIVE: To report the case of a patient who developed a life-threatening agranulocytosis and acute tubular necrosis after the administration of allopurinol and rofecoxib. CASE REPORT: After minor surgery, a 70-year-old male underwent a routine blood test which encountered: anemia, leucopenia, neutropenia, thrombopenia, and altered creatinine levels. Both marrow and renal biopsies were performed, yielding the following results: acute tubular necrosis and agranulocytosis in the recovery stage. One month and a half before the aforementioned surgery a routine blood test had been performed, which showed normal values. The patient had then received allopurinol 100 mg/day for around 2 months, and rofecoxib 2.5 mg/day for 14 days. DISCUSSION: After ruling out other possible causes, a diagnosis of iatrogenically induced agranulocytosis and acute tubular necrosis was reached. We used a (modified) Karch-Lasagna algorithm with both drugs, and found the following imputability values: possible for rofecoxib and probable for allopurinol. In view of the widespread use of rofecoxib and COX-2 inhibitors, despite their recent availability, and of their potential role in the severe adverse effects discussed, healthcare professionals must be on the alert for the development of symptoms suggesting said or other adverse effects.

Ectopic ACTH syndrome caused by pulmonary carcinoid tumourlets.

The differential diagnosis of Cushing's syndrome is a major challenge to clinical endocrinologists, especially those infrequent cases referred to as occult ectopic ACTH syndromes. Although bronchial carcinoids are well known to be a cause of Cushing's syndrome due to ectopic ACTH secretion, very few cases of carcinoid tumourlets causing an ACTH ectopic syndrome have been reported, and their origin remains controversial. For some authors, tumourlets and typical carcinoids represent distinct pathological entities, whilst others hold that tumourlets are merely microscopic carcinoid tumours. We report a patient with an aggressive Cushing's syndrome that required bilateral adrenalectomy, diagnosed 22 years before a 3-cm lung nodule became apparent on routine chest X-ray. The biopsy after lung surgery revealed a typical peripheral bronchial carcinoid surrounded by tumourlets. Both tumourlets and carcinoid tumour showed strongly positive ACTH immunostaining. Recently, Arioglu et al. (1998) reported a case of Cushing's syndrome caused by pulmonary carcinoid tumourlets, concluding that this entity should be considered in the differential diagnosis of occult ectopic ACTH syndrome. Furthermore, we consider that the carcinoid tumourlets found in our patient, were the initial source of ACTH, leading to Cushing's syndrome with a rapid onset, and that a loss of cell proliferation control in one of such tumourlets many years later, could have resulted in the development of a typical carcinoid tumour, reinforcing the theory of a common origin of these lesions.

Morphological changes to somatotroph cells and in vitro individual GH release, in male rats treated with recombinant human GH.

The effect of in vivo chronic administration of recombinant human growth hormone (rhGH) on morphology and individual GH release in somatotroph cells was evaluated in young male Wistar rats. Over an 18-day period, 30-day-old male rats were injected daily with 1.5 1U rhGH/kg (GPG group) or saline (VPG group) by subcutaneous injection. Electron-immunocytochemical, ultrastructural and morphometric studies of somatotroph cells were carried out. Additionally, rat pituitary cells were dispersed and overall and individual GH release was studied by radioimmunoassay and cell immunoblot assay (quantified by image analysis), respectively. The ultrastructure and size of somatotroph cells did not change, but volume density of secretion granules was reduced (p<0.01) by previous in vivo GH treatment. At four days, basal GH release of rat pituitary cell monolayer cultures was lower in the GPG group than in the VPG group (p<0.05); after 12 hours of culture, GHRH stimulation of GH release was lower in the GPG group than in the VPG group (p<0.05), and GHRH+SRIH inhibited GH release in the GPG group (p<0.05), but not in the VPG group. The percentage of somatotroph cells was not modified, but the ratio of strongly/weakly GH-immunostained cells had changed; weakly GH-immunostained cells increased from 34% to 55%. Moreover, in vitro treatment with GHRH, SRIH, and both, easily changed the strongly/weakly GH-immunostained cell ratio. Individual GH release, however, was not changed by previous in vivo GH treatment, although GHRH preferably stimulated a subpopulation of GH cells and SRIH did not inhibit individual GH release. These data suggest that exogenous chronic rhGH treatment down-regulates somatotroph function by modifying the proportion of GH cell subpopulation.

Molecular analysis of lineage-specific chimerism and minimal residual disease by RT-PCR of p210(BCR-ABL) and p190(BCR-ABL) after allogeneic bone marrow transplantation for chronic myeloid leukemia: increasing mixed myeloid chimerism and p190(BCR-ABL) detection precede cytogenetic relapse.

We studied lineage-specific chimerism and minimal residual disease (MRD) in sequential posttransplant samples from 55 patients who underwent unmanipulated (n = 44) or partially T-cell-depleted (n = 11) allogeneic bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Chimerism was assessed by polymerase chain reaction (VNTR [variable number of tandem repeats]-PCR) analysis in highly purified CD19+, CD3+, CD15+, and CD56+ cell fractions, whereas MRD was investigated in whole blood by reverse transcriptase-PCR (RT-PCR) of both p210(BCR-ABL) and p190(BCR-ABL) hybrid transcripts. Of 55 patients, 14 (including 6 T-cell-depleted patients) had cytogenetic relapse at 5-80 months and progressed to hematologic relapse, while 41 patients remained in prolonged cytogenetic remission 12-107 months post-BMT. Before leukemia recurrence, patients in the relapse group showed a consistent evolution pattern sequentially featured by persistent p210(BCR-ABL) positivity, increasing mixed chimerism (MC) in myeloid cells, p190(BCR-ABL) positivity, and, finally, cytogenetic relapse. Myeloid MC preceded cytogenetic relapse by 2-12 months, whereas p190(BCR/ABL) was detected 1-6 months prior to cytogenetic relapse in 11 patients and concomitant with cytogenetic relapse in 3 patients. In the remission group, all patients invariably tested negative for p190(BCR-ABL); 10 patients tested positive for p210(BCR-ABL) at variable time-points but showed persistent full donor chimerism (DC), whereas 31 patients tested p210(BCR-ABL) negative and displayed full DC or transient MC due to the persistence of recipient T cells. Two patients in the relapse group were successfully reinduced into molecular remission with donor lymphocyte infusion. Sequential molecular analysis after such treatment showed the inverse pattern to that observed prior to relapse, ie, progressive disappearance of p190(BCR-ABL) transcripts, conversion of myeloid chimerism to donor type, and, finally, p210(BCR-ABL) negativity. We conclude that lineage-specific chimerism and p190(BCR-ABL) messenger RNA (mRNA) analyses contribute a better characterization of CML evolution after BMT and enable early identification of patients at the highest risk of relapse. (Blood. 2000;95:2659-2665)

Susceptibility of HIV-1-TAT transfected cells to undergo apoptosis. Biochemical mechanisms.

The effects of HIV-1 Tat protein on mitochondria membrane permeability and apoptosis were analysed in lymphoid cells. In this report we show that stable-transfected HIV-Tat cells are primed to undergo apoptosis upon serum withdrawal. This effect was observed in both the Jhan T cell line and the K562 cells, the latter expressing the bcr-abl chimeric gene, which confers resistance to apoptosis induced by different stimuli. Using a cytofluorimetric approach we have determined that serum withdrawal induces a disruption of the transmembrane mitochondrial potential (Deltapsim) followed by an increase of reactive oxygen species (ROS) and the subsequent DNA nuclear loss in K562-Tat cells but not in the K562-pcDNA cell line. These pre-apoptotic events were associated with the cleavage of the caspase-3, while the expression of Bcl-2, Bcl-XL and Bax proteins was not affected by the presence of Tat. Regardless of the steady state of the Bax protein, we found that in both K562 and K562-Tat cells, this protein is located in the nucleus, but after serum withdrawal its localization was mainly in the cytoplasm. The activity of caspase-3 detected in K562-Tat cells after serum withdrawal paralleled with the mitochondria permeability transition. Nevertheless, in Jhan-Tat cells the inhibition of this caspase with the specific inhibitor, z-DEVD-cmk, did not affect the disruption of the mitochondria potential induced by serum withdrawal. Interestingly, we found that HIV-Tat protein accumulates at the mitochondria in the K562-Tat cells cultured under low serum conditions, and this mitochondrial localization correlated with the Deltapsim disruption detected in these cells. In addition, HIV-1 Tat protein synergies with protoporphyrin IX (PPIX), a ligand of the mitochondrial benzodiazepine receptor, in the induction of apoptosis in both Jhan and K562 cells. Thus, HIV-1 Tat protein may induce apoptosis by a mechanism that involves mitochondrial PT and may contribute to the lymphocyte depletion seen in AIDS patients.

In vitro effects of ketoconazole on corticotrope cell morphology and ACTH secretion of two pituitary adenomas removed from patients with Nelson's syndrome.

The direct effects of ketoconazole on the secretion of ACTH by human pituitary adenoma cells from 2 patient with Nelson's syndrome were studied in vitro. Stereologically quantified, intracellular changes affect the surface density of the endoplasmic reticulum (it decreased by 73%), the volume density of the secretion granules (it decreased by 49%), and the volume density of lysosomes (it decreased by 67%). The hormone released in the culture medium decreased depending on the doses of ketoconazole used; 10 mumol/l decreased ACTH levels by 31%. These data show that ketoconazole induce marked changes on corticotrope morphology and ACTH secretion in pituitary cells obtained from patients with Nelson's syndrome.

In vitro short-term effects of SMS 201-995, bromocriptine and TRH on growth hormone cell morphology from human pituitary adenomas.

This study reports, by immunocytochemistry, ultrastructure and morphometry, the in vitro effects of SMS 201-995 (10 nM), bromocriptine (1 microM) and TRH (10 microM) on the morphology of cells from two acromegalic patient adenomas containing immunoreactive growth hormone (GH). By electron microscopy, one tumor presented numerous large secretory granules (densely granulated growth hormone cell adenoma) while they were scarce and small in the other (sparsely granulated growth hormone cell adenoma); fibrous bodies could be seen in the specimen and in vitro. In the sparsely granulated growth hormone cell adenoma, TRH produced an increase in endoplasmic reticulum surface density compared to the other cultures. Bromocriptine increased the number and decreased the secretory granule diameters, while SMS 201-995 produced no significant changes in the same time. In the densely granulated growth hormone cell adenoma, the three substances increased the number of granules. TRH increased the mitochondrial volume density and endoplasmic reticulum surface density (with respect to the other cultures). SMS 201-995 decreased the mitochondrial and lysosome volume densities and endoplasmic reticulum surface density. We conclude that 1) TRH produces in cultured cells of both adenoma types an increase in cellular activity. 2) In cultured sparsely granulated growth hormone adenoma cells, bromocriptine has a stronger inhibitory effect than SMS 201-995. In cultured densely granulated growth hormone cells adenoma, bromocriptine has smaller inhibitory effect than SMS 201-995.