Lactate stimulates progesterone secretion via an increase in cAMP production in exercised female rats

The effect of exercise on the production of ovarian progesterone was examined in female rats. During in vivo experiments, diestrous rats were catheterized via the right jugular vein (RJV), and blood samples were collected before and after 10, 15, 30, and 60 min of swimming. In addition, blood samples were collected from the RJV before and 2, 5, 10, 15, 30, 60, and 120 min after 10 min of infusion of lactate (13 mg.kg-1.min-1) through the left femoral vein. To explore if lactate modulates progesterone secretion by acting directly on rat ovary or on anterior pituitary gland (AP), an in vitro experiment that mimicked the in vivo condition was performed. The ovarian tissue was challenged with lactate (0.01-10 mM) or porcine follicle-stimulating hormone (1 microgram/ml) and 3-isobutyl-1-methylxanthine (1 mM) for 60 min, and the AP was challenged with lactate ranging from 0.1 to 10 mM or 10 nM gonadotropin-releasing hormone for 30 min. The postexercise levels of plasma glucose, lactate, and progesterone at 10, 15, and 30 min were significantly higher than the corresponding basal levels. Plasma luteinizing hormone (LH) did not change after exercise. An elevation of plasma lactate and progesterone was found at 15 and 30 min subsequent to 10 min of infusion of lactate. Lactate ranging from 0.01 to 10 mM significantly increased ovarian adenosine 3',5'-cyclic monophosphate (cAMP) and progesterone production in a dose-dependent manner. LH concentration in plasma was not changed subsequent to lactate infusion. LH level in media samples was not altered after incubation of AP with lactate. These results suggest that the increase of plasma progesterone level in rats during exercise is independent of LH secretion and at least in part is due directly to a stimulatory effect of lactate on the production of ovarian cAMP.

Use of the silicone tracheal T-tube for tracheostenosis or tracheomalacia

BACKGROUND

Tracheobtenosib and tracheomalacia are trivial diseases. The conventional choice of managements with tracheostomy, either temporary or long-term usage, can only partially resolve the problems of airway obstruction. Silicone tracheal T-tube presents a substitute for it.

METHODS

We present 5 patients with tracheostenosis or tracheomalacia managed with nine procedures of long silicone Montgomery T-tube prothesis between 1984 and 1994 in VGH-Taipei. The primary diagnosis included tracheal injury (2), postintubation tracheal stenosis (2), and stenosis due to endotracheal tuberculosis (1). Three patients received a long segmental T-tube for permanent endotracheal stenting and the other two patients used T-tube insertion for temporary stenting of the trachea for 7 and 11 months, respectively, with satisfactory results.

RESULTS

All patients got immediate benefit from the prothesis in respiration with simple postoperative care. Two patients with temporary T-tube placement had it successfully removed in 7 and 11 months, respectively. Placement of the T-tube for subglottic stenosis also protected the function of phonation. The tracheal T-tube restored airway patency reliably with good long-term results and could be the preferred management of chronic upper airway obstructive disease not amenable to surgical repair. The most common complication was airway obstruction caused by either granulations or sticky mucoid substance. Three patients and six tubes (60%) developed granulation obstruction and the average duration of granuloma formation was 7.7 months. Laser phototherapy or surgical intervention, such as tracheoplasty, with change of the T-tube was carried out for granuloma obstruction.

CONCLUSIONS

T-tube is a good endoprothesis for tracheostenosis and tracheomalacia with minimal complication for cases of long tracheostenosis or complex tracheal injury.

Direct measurement of neutrophil F-actin content in microvolume whole blood samples

BACKGROUND

The traditional methods of measuring F-actin content in neutrophils required a large blood sample and a series of isolation procedures. To reduce the disturbing effect on neutrophils, a new method was designed to measure the neutrophil F-actin content directly in microvolume whole blood samples.

METHOD

The neutrophil F-actin content was measured in 100 microliters of whole blood directly after formyl-Met-Leu-Phe (FMLP) stimulation and lysis of red blood cells (with FACS lysing solution, Becton, Dickinson Immunocytometry Systems, San Jose, Calif.).

RESULTS

This method resulted in a typical dose-dependent increase in the neutrophil F-actin content in response to FMLP similar to that using isolated neutrophils. However, the relative F-actin content of whole blood samples was significantly higher than those of isolated neutrophils at 60 and 300 s after stimulation (2.44 +/- 0.21 vs. 2.00 +/- 0.22 at 60 s, p < 0.05, n = 16; 1.77 +/- 0.19 vs. 1.48 +/- 0.19 at 300 s, p < 0.05, n = 16). The histograms of whole blood samples at 30 and 60 s after stimulation showed a subpopulation (17.5 +/- 2.7%) of lower F-actin content, which cannot be definitely identified in the isolated neutrophil samples. Furthermore, the neutrophil actin response to FMLP in a pair of premature twins was analyzed using this method. The response of the healthy twin is similar to that of the adult volunteers while that of the septic one is characterized by an increasing number of nonresponsive cells as the clinical condition deteriorated.

CONCLUSION

This new method is effective in evaluating the neutrophil F-actin content even in premature infants. It is characterized by avoiding most of the isolation procedures which might have an activating effect on neutrophils. Besides, the study of the twins also indicated the usefulness of this method in monitoring the clinical course of neonatal sepsis.

Cloning and functional characterization of human heteromeric N-methyl-D-aspartate receptors

Human cDNAs encoding N-methyl-D-aspartate receptor type (NMDAR)1A, NMDAR2A and NMDAR2B subunits were cloned and receptors encoded by these cDNAs were functionally expressed by injection of the respective mRNAs in Xenopus oocytes. The pharmacological properties of recombinant human N-methyl-D-aspartate (NMDA) receptors were characterized by profiling two agonists and four antagonists at both the NMDA and glycine sites in voltage-clamped oocytes. NMDA, glycine and D-serine were significantly more potent at human NMDAR (hNMDAR)1A/2B receptors than at nNMDAR1A/2A, whereas there was no detectable subtype-dependent difference in the potency of glutamate. Of the NMDA-site antagonists tested, CGP 43487 and 3-(2-carboxypiperazin-4-yl) propyl-1-phosphonate exhibited 5.8- and 3.9-fold greater potency, respectively, at hNMDAR1A/2A receptors than at hNMDAR1A/2B. Of the four glycine-site competitive antagonists tested, L-689,560 displayed 5-fold greater potency at hNMDAR1A/2A, whereas 5,7-dichlorokynurenic acid, HA-966 and CGP 58411 did not discriminate between hNMDAR1A/2A and hNMDAR1A/2B. Receptors resulting from injection of hNMDAR1A, hNMDAR2A and hNMDAR2B transcripts in a 1:1:1 ratio were indistinguishable from hNMDAR1A/2B receptors in terms of their sensitivity to NMDA, glycine, D-serine, CGS 19755 and CGP 40116. Ifenprodil was approximately 350-fold more potent at hNMDAR1A/2B than at hNMDAR1A/2A receptors. Ifenprodil sensitivities of receptors formed in oocytes injected with a constant amount of hNMDAR1A mRNA but varying ratios of hNMDAR2A or hNMDAR2B mRNAs were compared. The receptors expressed at a 10:1 ratio of 2A:2B transcripts displayed an ifenprodil sensitivity that would be predicted for a population in which 51% was represented by hNMDAR(1A)2(2A)3 complexes. Our results underscore the need for subtype-selective compounds acting at novel sites to sufficiently probe the pharmacological differences between NMDA receptor subtypes formed by different subunit combinations.

Inhibition by amphetamine of testosterone secretion through a mechanism involving an increase of cyclic AMP production in rat testes

1. The effect of amphetamine on the secretion of testosterone and the production of testicular adenosine 3':5'-cyclic monophosphate (cyclic AMP) in rats was studied. 2. A single intravenous injection of amphetamine decreased the basal and human chorionic gonadotropin (hCG)-stimulated levels of plasma testosterone. Plasma LH levels were not altered by the injection of amphetamine. 3. Administration of amphetamine in vitro resulted in a dose-dependent inhibition of both basal and hCG-stimulated release of testosterone. 4. Amphetamine enhanced the basal and hCG-increased levels of cyclic AMP accumulation in vitro in rat testes. 5. These results suggest that amphetamine inhibits the spontaneous and hCG-stimulated secretion of testosterone from the testes through a mechanism involving an increase in cyclic AMP production.

Diagnostic imaging in the evaluation of dysphagia

Evaluation of dysphagia is a challenge commonly encountered by family physicians. Dysphagia may be classified as either the oropharngeal type or the esophageal type and may have a variety of etiologies. Possible causes of oropharyngeal dysphagia include Zenker's diverticulum, pharyngeal carcinoma, pharyngeal webs and strictures, lateral pharyngeal pouches and neuromuscular diseases. Esophageal dysphagia can be caused by esophageal carcinoma, esophageal stricture and webs, achalasia, diffuse esophageal spasm and scleroderma, caustic esophagitis and infectious esophagitis. Studies using different textures of barium allow evaluation of the swallowing mechanism. Static images are obtained to evaluate the integrity of the mucosa.

Late-onset idiopathic hypoparathyroidism with thymoma: a case report

A 62-year-old male was admitted because of numbness and twitching of both hands. Hypocalcemia with positive Trousseau's sign was noted. Chest X-ray and computed tomography (CT) showed an anterior mediastinal mass. Skull X-ray and whole body bone scan could not rule out bony metastasis to the left parietal bone, causing an anterior mediastinal tumor with bony metastasis to be suspected initially. Median sternotomy and extended thymectomy were done, and Stage II thymoma with negative calcitonin staining was noted. However, hypocalcemia persisted after thymectomy and the results of pre-operative and post-operative intact-parathyroid hormone (intact-PTH) were less than the detection limit (<13.3 pg/ml). Tumor markers and gallium tumor scan were all negative. Brain CT disclosed calcification over the bilateral basal ganglia and bilateral dentate nuclei of the cerebellum; the supposed metastatic osteolytic lesions of parietal bone were considered to result from pacchionion arachnoid granulation tissues. The coexistence of late-onset idiopathic hypoparathyroidism and thymoma has not been reported before. Long-term replacement therapy with vitamin D and calcium was necessary for this case.

Effect of maternal labor and mode of delivery on neutrophil actin response to N-formylmethionyl-leucyl-phenylalanine in healthy neonates

Diminished actin response to N-formyl-methionyl-leucyl-phenylalanine (FMLP) has been used to explain the impaired chemotaxis of neonatal neutrophils, but the effect of labor on this response has not been evaluated before. Therefore, we tested the hypothesis that labor stress may have an effect on actin response of cord blood neutrophils to FMLP. This response is compared by phallacidin stain of neutrophil F-actin and flow cytometry analysis among 3 groups of healthy neonates: group I, 16 vaginally delivered neonates; group II, 16 neonates delivered by elective cesarean section without labor; and group III, 16 neonates delivered by cesarean section after labor. In the group III, 10 infants were delivered by an emergency cesarean section because of fetal heart rate deceleration indicating fetal distress (one minute Apgar score < 7 in 5 cases [50%]), and the other 6 infants were delivered because of failure of progression of labor (one minute Apgar score < 7 in 2 cases [33.3%]). Stimulated relative F-actin content of neutrophils in group III was increased compared with groups I and II. There was no such difference between neutrophils from infants of groups I and II. The results of this study indicate that fetal distress may enhance neutrophil actin response to FMLP, while labor or mode of delivery might not have such effect.

Outbreak of obstructive ventilatory impairment associated with consumption of Sauropus androgynus vegetable

BACKGROUND

Forty four individuals, suffering from temporary insomnia and poor appetite followed by progressive difficulty breathing after four weeks or more ingestion of the Sauropus androgynus or Sabah vegetable, were reported to the National Poison Center of Taiwan by physicians between August 23, 1994 and August 25, 1995.

OBJECTIVE

A telephone questionnaire survey was designed and conducted to collect demographic data, information about use of the vegetable, past medical history and clinical presentation. Laboratory data were obtained from their physicians as available.

RESULTS

Forty one patients, predominantly women, 43 +/- 11 years old, were identified in our survey. They reported a variety of sources and preparation methods for the vegetable. Difficulty breathing, identified in 36 cases, was the clinical hallmark. Twenty people gave a history of dyspnea delayed until 44 +/- 40 days after discontinuing vegetable consumption. Laboratory evidence of obstructive ventilatory impairment (FEV1/FVC 56 +/- 12%, FEV1 31 +/- 6%, PaO2 71 +/- 15%) was observed in 12 cases tested. An open lung biopsy performed in a demonstration case disclosed bronchiolitis obliterans organizing pneumonia.

CONCLUSION

In this case series of 41 victims, we have identified a severe pulmonary effect and hypothesize that it is related to consumption of sauropus androgynus vegetable. Papaverine has been previously identified in this vegetable but is unlikely to be responsible for the full range of toxicity seen.

Evolutionary origins of retroposon lineages of Mhc class II Ab alleles

Major histocompatibility complex (Mhc) class II Ab genes have evolved into three distinct lineages. While lineage 2 alleles differ from lineage 1 alleles by the insertion of a retroposon in intron 2, the basis for the extremely large intron 2 in lineage 3 alleles has heretofore been undetermined. In this report, we demonstrate by nucleotide sequencing that the genomic sequences of prototypic alleles from all three lineages diverge significantly and that lineage 3 is derived from lineage 2 by two insertional events in intron 2. One insert, composed of a member of B1 short interspersed repetitive elements (SINEs), occurs 508 base pairs (bp) 3' of exon 2, and the other, 1141 bp 3' of exon 2 within the retroposon that distinguishes lineage 2 from lineage 1. To assess the evolutionary stability of these lineages and the extent of ancestral polymorphisms of Ab within Mus species, we extended our restriction site polymorphism analysis to include 86 alleles from 120 independently derived H2 haplotypes from 12 separate species and subspecies of Mus. A phylogenetic tree revealing the relationships of these Ab alleles with respect to restriction site polymorphisms, but excluding the retroposon insertions, demonstrated that these lineages have distinctive genomic structures beyond the retroposon polymorphisms. In summary, these mouse Ab genes were produced from successive retroposon insertion events. Lineage 1 and 2 were detected in a variety of Mus species, including Mus caroli, indicating that these lineages diverged more than 2 million years ago. Lineage 3 alleles were found only in the Mus musculus subspecies, suggesting that it diverged from lineage 2 more recently. These results indicate that all three lineages of Ab have persisted through several speciation events in the genus Mus.

Progesterone stimulates in vitro release of prolactin and thyrotropin involving cAMP production in rat pituitary

Effects of progesterone administration in vivo or in vitro on the release of pituitary prolactin (PRL) and thyroid stimulating hormone (TSH) in vitro, as well as the generation of pituitary cyclic adenosine 3', 5'-monophosphate (cAMP) were studied in ovariectomized (Ovx) rats. Ovx rats were either decapitated or injected subcutaneously with progesterone, or oil for 3 days before decapitation. The anterior pituitary glands (APs) of progesterone treated Ovx rats were incubated with Locke's medium containing thyrotropin-releasing hormone (TRH, 10 nM) and/or 3-isobutyl-1-methylxanthine (IBMX, 1 mM) at 37 degrees C for 30 min. The APs of untreated Ovx rats were incubated in vitro with IBMX and progesterone (0, 0.1, 1, 10 nM). Progesterone increased spontaneous and TRH-induced release of PRL and TSH in vitro. Administration of progesterone, either in vivo or in vitro, increased the production of pituitary cAMP following incubation of IBMX. These results suggest that progesterone increases the release of PRL and TSH through a mechanism associated with an increase of cAMP production in rat APs.

Mediastinal liposarcoma with local recurrence: a case report

Liposarcoma is a rare mediastinal tumor. The treatment of choice is surgical resection. However, recurrence is not uncommon. In this report, recurrence of liposarcoma with local extension to chest wall is described in a 70-year-old Chinese male who had liposarcoma located in the anterior mediastinum and underwent tumor resection 5 years before. Long-term follow-up is indicated in patients with mediastinal liposarcoma because there may be an interval of several years between resection and recurrence.

Membrane transport mechanisms probed by capacitance measurements with megahertz voltage clamp

We have used capacitance measurements with a 1-microsecond voltage clamp technique to probe electrogenic ion-transporter interactions in giant excised membrane patches. The hydrophobic ion dipicrylamine was used to test model predictions for a simple charge-moving reaction. The voltage and frequency dependencies of the apparent dipicrylamine-induced capacitance, monitored by 1-mV sinusoidal perturbations, correspond to single charges moving across 76% of the membrane field at a rate of 9500 s-1 at 0 mV. For the cardiac Na,K pump, the combined presence of cytoplasmic ATP and sodium induces an increase of apparent membrane capacitance which requires the presence of extracellular sodium. The dependencies of capacitance changes on frequency, voltage, ATP, and sodium verify that phosphorylation enables a slow, 300- to 900-s-1, pump transition (the E1-E2 conformational change), which in turn enables fast, electrogenic, extracellular sodium binding reactions. For the GAT1 (gamma-aminobutyric acid,Na,Cl) cotransporter, expressed in Xenopus oocyte membrane, we find that chloride binding from the cytoplasmic side, and probably sodium binding from the extracellular side, results in a decrease of membrane capacitance monitored with 1- to 50-kHz perturbation frequencies. Evidently, ion binding by the GAT1 transporter suppresses an intrinsic fast charge movement which may originate from a mobility of charged residues of the transporter binding sites. The results demonstrate that fast capacitance measurements can provide new insight into electrogenic processes closely associated with ion binding by membrane transporters.

Dynamic evaluation of swallowing in patients with cerebrovascular accident

To determine the specific effects of cerebrovascular accident (CVA) on deglutition, especially relative to the site of CVA, we studied videotapes of barium swallow examinations in 74 patients who had had a CVA. Although there was no distinct correlation between the prevalence of oral and pharyngeal dysfunction and the site of CVA, left CVA was prone to impair only the oral phase, and right CVA tended to impair both phases.

MELAS syndrome associated with diabetes mellitus and hyperthyroidism: a case report from Taiwan

MELAS syndrome is a form of mitochondrial myopathy with manifestations of seizure, stroke-like syndrome, lactic acidosis, ragged red muscle fibres and mitochondrial encephalopathy. The syndrome has been reported in association with a variety of endocrine and metabolic disorders including diabetes mellitus (DM), hypothalamo-pituitary hypofunction, hypothalamic growth hormone deficiency and delayed puberty. Mitochondrial DNA (mtDNA) point mutation may be the major pathological defect. However, association of MELAS syndrome with hyperthyroidism has not previously been reported. A case is reported from Taiwan of a 32-year-old woman suffering from MELAS syndrome with associated DM and hyperthyroidism. When the latter was diagnosed in April 1988, the patient underwent subtotal thyroidectomy. There was no family history of thyroid disease. Because of repeated seizures, she had computed tomography (CT) and magnetic resonance imaging (MRI) of the brain which showed focal, low-density lesions over the cerebral hemispheres. Both serum and cerebral spinal fluid lactic acid levels were elevated. Mild elevations of serum T4 and T3 and a high titre of TSH receptor antibody were still present. Hyperglycaemia was noted during hospitalization and DM confirmed by oral glucose tolerance test. Muscle biopsy showed ragged red fibres. DNA analysis showed an A-to-G transition at the 3243rd nucleotide position of the tRNA(Leu(UUR)) gene of the mtDNA from the patient. Quantitative polymerase chain reaction (PCR) and restriction analysis revealed that about 60% of the blood mtDNA was of mutant type. The patient received antithyroid drugs for hyperthyroidism, diet control for DM and anti-epileptic drugs for seizure.

Diminished actin polymerization of neonatal neutrophils determined by a microvolume whole blood method

To investigate the actin response to chemotactic stimulation of neonatal neutrophils, we developed a new procedure to measure neutrophil F-actin content directly in microvolume whole blood (100 microliters sample each test). Using this procedure, we compared neutrophil actin response to N-formyl-methyonyl-leucyl-phenylalanine (FMLP) between groups of normal neonate and adult volunteers. Relative F-actin content (FMLP/control ratio) of neonatal neutrophils is significantly lower than those of adult volunteers' neutrophils both at 30 sec (1.94 +/- 0.34 vs. 2.25 +/- 0.31; n = 16, p < 0.05, t test) and 60 sec (2.23 +/- 0.19 vs. 2.40 +/- 0.27; n = 16, p < 0.05, t test) after FMLP stimulation. These results provide new evidence of impairment of neutrophil actin response in the neonate, which may partially explain the observed chemotactic defect in neonatal neutrophils.

Key role of a CCAAT element in regulating hepatitis B virus surface protein expression

Two separate promoters, the upstream preS1 and the downstream S promoters, give rise to transcripts encoding three forms of the hepatitis B virus surface protein. Overproduction of large surface protein because of increased preS1 transcripts leads to a block in secretion of all forms of the surface protein and of virion particles. We show here that a CCAAT element in the S promoter not only increases the amount of S transcripts, but also decreases the amount of preS1 transcripts by up to fivefold. Consequently, mutations in this element cause intracellular accumulation of surface proteins because of the secretory block. Therefore, this CCAAT element appears to be critical for maintaining the high ratio of S versus preS1 transcripts that is necessary for the viral life cycle.

Gastric inhibitory polypeptide and gastric acid secretion in pregnant rats

The effects of pregnancy on the basal and pentagastrin-stimulated gastric acid secretion and the level of plasma gastric inhibitory polypeptide (GIP) in rats were studied on pentobarbital-anaesthetized non-pregnant rats and rats in the 1st, 2nd, or 3rd week of gestation. Acid output was determined by titration of the gastric perfusate. Basal secretion was collected for 45 min before a 30 min infusion of pentagastrin (8 micrograms/ml/300 g body weight). Concentration of plasma GIP was measured by a radioimmunoassay (RIA). The immunoreactivity of GIP-like substance in the extract of the rat placenta collected from the rat at day 21 of gestation was examined by RIA. The biological activity of GIP-like substance in the rat placenta extract was tested by the reduction of pentagastrin-stimulated gastric acid secretion in male rats. The basal level of gastric secretion was higher in late pregnancy as compared with the non-pregnant rats. Pentagastrin induced a greater increase of gastric acid secretion in early but not late pregnant rats as compared with the non-pregnant animals. The basal and post-pentagastrin level of plasma GIP was higher in rats in late pregnancy. Both immunoreactivity and biological activity of GIP exist in the rat placenta extract. These results suggest that the normalization of gastric acid secretion in late pregnant rats is at least in part due to the production of GIP-like substance from placenta.

Insulin autoimmune syndrome in a patient with methimazole and carbimazole-treated Graves' disease: a case report

Insulin autoimmune syndrome (IAS) includes fasting or reactive hypoglycemia, hyperinsulinemia and the presence of insulin-binding antibodies in patients who have never been exposed to exogenous insulin. The report concerns a 34-year-old male patient with Graves' disease who had history of having taken methimazole for two months, without any consequence, 4 years previously. However, when methimazole was again administered for three weeks followed by a week of carbimazole, the patient suffered hypoglycemia 4 times during the next 4 weeks. He denied history of diabetes mellitus (DM), of taking any oral hypoglycemic agent or of having received insulin injection. Laboratory data showed total serum insulin level > 320 microU/mL, free insulin 55 microU/mL and insulin antibody 88.3%. Oral glucose tolerance test (OGTT) revealed DM pattern. Since the patient had history of allergy to anti-thyroid drugs before this event, so he was treated with radioiodine (131I). There was no episode of hypoglycemic attack during 15 months of follow-up.

Ancient origin of the vacuolar H(+)-ATPase 69-kilodalton catalytic subunit superfamily

Recently, two distinct cDNA clones encoding the catalytic subunit of the vacuolar H(+)-ATPase (V-ATPase) were isolated from the allotetraploid cotton species Gossypium hirsutum L. cv 'Acala SJ-2' (Wilkins 1992, 1993). Differences in the nucleotide sequence of these clones were used as molecular markers to explore the organization and structure of the V-ATPase catalytic subunit genes in the A and D genomes of diploid and allotetraploid cotton species. Nucleotide sequencing of polymerase chain reaction (PCR) products amplified from G. arboreum (A2, 2n=26), G. raimondii (D5, 2n=26), and G. hirsutum cv 'Acala SJ-2' [(AD)1, 2n=4x=52] revealed a V-ATPase catalytic subunit organization more complex than indicated hitherto in any species, including higher plants. In the genus Gossypium, the V-ATPase catalytic subunit genes are organized as a superfamily comprising two diverse but closely related multigene families, designated as vat69A and vat69B, present in both diploid and allotetraploid species. As expected, each vat69 subfamily is correspondingly more complex in the allotetraploid species due to the presence of both A and D alloalleles. Because of this, about one-half of the complex organization of V-ATPase catalytic subunit genes predates polyploidization and speciation of New World tetraploid species. Comparison of plant and fungal V-ATPase catalytic subunit gene structure indicates that introns accrued in the plant homologs following the bifurcation of plant and fungi but prior to the gene duplication event that gave rise to the vat69A and vat69B genes approximately 45 million years ago. The structural complexity of plant V-ATPase catalytic subunit genes is highly conserved, indicating the presence of at least ten introns dispersed throughout the coding region.

Calcitonin inhibits testosterone and luteinizing hormone secretion through a mechanism involving an increase in cAMP production in rats

Effects of calcitonin peptides, including human calcitonin (hCT), salmon calcitonin (sCT), and calcitonin gene-related peptide (CGRP), on the secretion of testosterone and luteinizing hormone (LH) in male rats were studied. Male rats were injected intravenously with human chorionic gonadotropin (hCG), calcitonin peptides, or hCG plus calcitonin peptides. Blood samples were collected at several intervals following hormone challenge. In an in vitro experiment, testis blocks were incubated with hCG (0, 0.05, 0.5, or 5 IU/ml) or hCG (0.5 IU/ml) plus calcitonin peptides (0-10(-9) or 10(-6) M) at 34 degrees C for 30 minutes. Both medium and plasma samples were extracted by ether and analyzed for testosterone by radioimmunoassay (RIA). The concentration of calcium in each plasma sample was measured by an automatic calcium analyzer. The anterior pituitary gland (AP) was incubated with or without calcitonin peptides (0-10 nM) at 37 degrees C for 30 minutes. They were then incubated with gonadotropin releasing hormone (GnRH, 10 nM) for a further 30 minutes. The concentration of LH in AP medium was measured by RIA. The accumulation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in both testicular tissues and APs were measured by RIA. A single intravenous injection of calcitonin peptides decreased the basal and hCG-stimulated levels of plasma testosterone gradually from 60 to 180 or 360 minutes after challenge. The plasma calcium was not altered by the injection of calcitonin peptides and/or hCG. Administration of calcitonin peptides in vitro resulted in a dose-dependent inhibition of both basal and hCG-stimulated release of testosterone.(ABSTRACT TRUNCATED AT 250 WORDS)

Ectopic gastric mucosa in the upper esophagus: detection and radiographic findings

PURPOSE

To detect and characterize the appearance of islands of ectopic gastric mucosa in the upper esophagus at routine examination of the upper gastrointestinal (GI) tract.

MATERIALS AND METHODS

Well-distended upper esophagus was documented with spot radiographs obtained with routine double-contrast examination performed after administration of high-density barium in nine patients. Detected lesions were confirmed by means of endoscopy and biopsy.

RESULTS

Twelve lesions were detected. Radiographic findings were characterized by either a discrete, shallow depression surrounded by a subtle, rimlike elevation on double-contrast images or by a pair of small indentations on the same wall on full-column, single-contrast images at the level of the thoracic inlet. Endoscopic examination revealed well-circumscribed areas of reddish mucosa located 15-26 cm from the incisors.

CONCLUSION

Ectopic gastric mucosa in the upper esophagus is easily demonstrated at routine examination of the upper GI tract. Diagnosis can be based on location and characteristic radiographic appearance.

CT findings of plexiform neurofibromatosis involving the ileum and its mesentery

We present a case of plexiform neurofibromatosis involving the ileum and its mesentery. Computed tomography (CT) scans showed a cluster of small soft-tissue density nodules, which represented a cross-sectional image of the enlarged peripheral nerves and wall thickening of the distal ileum. Trapped fat tissue was demonstrated between these enlarged nerves. Histopathologic studies of the resected specimen correlated well with CT findings.

Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Chinese infants with or without severe neonatal hyperbilirubinaemia

To characterize mutations in the glucose-6-phosphate dehydrogenase (G6PD) gene in Chinese infants, we studied 213 G6PD-deficient infants without blood exchange transfusion (BET) therapy, and 34 patients who required BET therapy for their severe hyperbilirubinaemia after birth. Nine different point mutations were characterized in all infants. Of these mutations, the G to T substitution at cDNA nucleotide (nt) 1376, which accounts for the mutations in 131 (53.0%) neonates, followed by G to A substitution at nt 1388 in 18 (10.5%) infants, A to G substitution at nt 493 in 17 (6.9%) infants, A to G substitution at nt 95 in 10 (4.1%) infants, C to T substitution at nt 1024 in six (2.4%) infants, and G to T substitution at nt 392 in three (1.2%) infants, G to A substitution at nt 487 in two (0.8%) infants, C to T substitution at nt 1360 in two (0.8%) infants and C to T substitution at nt 592 in two (0.8%) infants. Mutations in 48 (19.5%) G6PD-deficient infants were not characterized. Most (64.7%) mutations in the G6PD-deficient infants who required BET therapy after birth result from a G to T substitution at nt 1376. The enzyme activity of G6PD deficient infants who required BET therapy is significantly lower than for those who did not, even in a group with the same variant (as in 1376 mutation). Severe neonatal jaundice requiring BET therapy can take place with the majority of variants encountered in this area.