Molecular cloning, sequencing and expression of obese gene in the Chinese

OBJECTIVE

To construct the human obese (ob) cDNA clone in the Chinese, and analyze the expression of the ob gene in adipose tissue of obese, non-obese subjects and nooinsulin-dependent diabetes mellitus (NIDDM) Chinese patients.

METHODS

A ob cDNA clone was isolated by reverse transcription polymerase chain reaction (RT-PCR). Four groups of Chinese subjects participated in the study: 1) 12 obese subjects [body mass index (BMI): 28.5 +/- 2.3 kg/m2]; 2) 11 non-obese subjects (BMI: 21.0 +/- 1.5 kg/m2); 3) 8 obese NIDDM patients (BMI: 27.0 +/- 1.4 kg/m2); 4) 11 non-obese NIDDM patients (BMI: 21.2 +/- 1.4 kg/m2). The expression of ob gene mRNA in abdominal subcutaneous adipose tissue was examined using RNA dot blot hybridization with a digoxigenin-labeled human ob cDNA probe. The hybridized signals were quantitated by densitometry.

RESULTS

A full human ob cDNA fragment which included a glutamine codon at +49 was obtained. A base substitution (A to G) in the coding region at position 287 was found, resulting in a glutamine being replaced by an arginine. Expression of the ob gene was significantly higher in Chinese obese subjects compared to non-obese ones (P < 0.05), and positively correlated with the BMI. No significant difference in the amount of ob mRNA was detected between non-diabetic and diabetic groups at the same BMI level.

CONCLUSIONS

We constructed a full length human ob cDNA clone. The expression of the ob gene was significantly higher in Chinese obese subjects than in non-obese ones. The metabolic and hormonal changes associated with NIDDM are not the main factors regulating the expression of the ob gene.

Novel pathway of metabolism of alpha-linolenic acid in the guinea pig

Docosahexaenoic acid (DHA) plays an important role in the nervous system. The capacity of the infant to use the essential fatty acid alpha-linolenic acid (ALA) as a substrate for neural DHA has been the subject of much debate recently. In this study, we explored the metabolic fate of an oral dose of 14C-labeled ALA in guinea pigs fed a defined diet for 3 wk from weaning. Of the 14C-labeled ALA administered, more than 46% was associated with the skin and fur lipids, mostly in the FFA fraction, and less than 0.1% was in brain lipids. About 39% of the label was not recovered in the body lipids and was assumed to be expired as CO2 or unabsorbed. The fur and skin were almost equally labeled; however, because of the very low mass of ALA in the fur, the specific activity of the fur was very high. These data identify a new route of metabolism of ALA in this species, presumably through the sebaceous glands onto fur. If this pathway exists in other species, including humans, it may account for the poor efficiency of conversion of ALA to DHA, because dietary ALA would not be available for anabolic pathways such as DHA synthesis. The relevance of these data to infants is that ALA may play an important hitherto unidentified role in the skin related to barrier function or epidermal integrity. This calls for more research into the importance of ALA as an essential fatty acid in its own right in human infants.

[The expression of the epidermal growth factor-receptor mRNA in laryngeal squamous cell carcinoma and its correlation with clinical pathological characteristics]

OBJECTIVE

To study the expression of the epidermal growth factor-receptor(EGF-R) mRNA in laryngeal squamous cell carcinoma and its correlation with clinical characteristic and difference of tissues.

METHOD

All 20 samples of laryngeal squamous cell carcinoma were determined by dot blot.

RESULT

The EGF-R mRNA expression was evaluated in 20 laryngeal squamous cell carcinomas and 15(75%) were finded with EGF-R mRNA expression. When the mRNA of the laryngeal squmous cell carcinoma was decreased, the expression of the EGF-R mRNA was decreased. The EGF-R mRNA expression did not correlated with age or tumor localization (P > 0.05) but correlated with differentiated tumors (P < 0.05) and the stages of TNM according to classification (P < 0.05). Four patients with recuence cancers and six patients with the metastatic cervical-lymph-node involvement had an enhanced expression of EGF-R mRNA.

CONCLUSION

The uncontrolled growth and proliferation of the laryngeal squmous cell carcinomas may be related to the abnormal EGF-R mRNA expression. The enhanced expression of EGF-R mRNA was correlated with the differentiation and stages of laryngeal squmous cell carcinomas.

Calcyclin gene expression is increased by mechanical strain in fibroblasts and lung

Mechanical tension extending throughout the structural elements of the lung is a potential stimulus for cell proliferation and gene expression. Pulmonary fibroblasts located in the interstitial space of the capillary wall throughout the lung parenchyma and within the large vessels and airways are uniquely situated to sense changes in mechanical force. Therefore, we used the polymerase chain reaction-based method of differential display analysis to screen for altered gene expression in fetal human lung fibroblasts exposed to increased cyclic stretch. IMR-90 cells were seeded at 3 x 10(4) cells/cm(2) on laminin-coated plates. Cells were subsequently exposed to mechanical strain on a Flexercell apparatus, resulting in a maximal elongation of 20% at a rate of 60 cycles/min over a period of 48 h. A complementary DNA corresponding to the cell cycle-regulated gene calcyclin was identified in mechanically strained fibroblasts. Increased calcyclin messenger RNA levels were confirmed by Northern blot analysis. Further, calcyclin gene expression was upregulated in isolated-perfused rat lungs exposed to increased mechanical strain by ventilation at high states of lung inflation for 4 h. These data suggest that calcyclin gene expression plays a role in the response of pulmonary fibroblasts to increased mechanical tension and may alter the regulation of the fibroblast cell cycle.

Mutations in the primer grip region of HIV reverse transcriptase can increase replication fidelity

Mutations in the primer grip region of human immunodeficiency virus reverse transcriptase (HIV-RT) affect its replication fidelity. The primer grip region (residues 227-235) correctly positions the 3'-ends of primers. Point mutations were created by alanine substitution at positions 224-235. Error frequencies were measured by extension of a dG:dA primer-template mismatch. Mutants E224A, P225A, P226A, L228A, and E233A were approximately equal to the wild type in their ability to extend the mismatch. Mutants F227A, W229A, M230A, G231A, and Y232A extended 40, 66, 54, 72, and 76% less efficiently past a dG:dA mismatch compared with the wild type. We also examined the misinsertion rates of dG, dC, or dA across from a DNA template dA using RT mutants F227A and W229A. Mutant W229A exhibited high fidelity and did not produce a dG:dA or dC:dA mismatch. Interestingly, mutant F227A displayed high fidelity for dG:dA and dC:dA mismatches but low fidelity for dA:dA misinsertions. This indicates that F227A discriminates against particular base substitutions. However, a primer extension assay with three dNTPs showed that F227A generally displays higher fidelity than the wild type RT. Clearly, primer grip mutations can improve or worsen either the overall or base-specific fidelity of HIV-RT. We hypothesize that wild type RT has evolved to a fidelity that allows genetic variation without compromising yield of viable viruses.

Relationship between casein kinase I isoforms and a neurofilament-associated kinase

Purified neurofilaments (NFs) contain an associated kinase (NFAK) activity that phosphorylates selectively a subset of sites in the tail of NF-M and has properties consistent with casein kinase I (CKI). Because CKI consists of a family of as many as seven genes (alpha, beta, gamma1-3, delta, and epsilon), we investigated the extent to which different CKI isoforms contribute to NFAK activity. Using an NF-M-derived substrate, we determined that NFAK activity copurified with casein kinase activity through two purification steps. In an in-gel kinase assay, NFAK activity occurred at 36-40 kDa, corresponding to the size of CKIalpha isoforms. Chicken neurons express transcripts encoding four alternatively spliced variants of CKIalpha (CKIalpha, CKIalphaS, CKIalphaL, and CKIalphaLS) differing in the presence or absence of two inserts, L and S. Using antibodies against different isoforms or with broad CKI specificity, we determined that all four CKIalpha variants, as well as other CKI family members, are present in chicken brain. However, only CKIalpha and CKIalphaS could be detected in purified NFAK. Also, immunoprecipitation studies showed that CKIalpha and CKIalphaS together account for NFAK activity. These findings raise the possibility that only a subset of CKI isoforms may be able to associate with and/or phosphorylate NFs.

Regulation of the expression of serotonin N-acetyltransferase gene in Japanese quail (Coturnix japonica): I. Rhythmic pattern and effect of light

Serotonin N-acetyltransferase [arylalkylamine N-acetyltransferase (AANAT); EC2.3.1.87] is the rate-limiting enzyme in melatonin synthesis, and its activity exhibits a diurnal rhythm similar to that of the melatonin content in the pineal gland and retina of Japanese quail. Studies were conducted to characterize the Japanese quail AANAT cDNA, and to evaluate the expression of AANAT mRNA in the pineal gland, the retina, and other peripheral tissues. The nucleic acid sequence of a 400 bp cDNA clone obtained by RT-PCR manifested 78 and 95% homology compared to the rat and chicken AANAT cDNA, respectively, while the deduced amino acid sequence homology was 82 and 99%, respectively. AANAT mRNA content in a single pineal gland or an aliquot of eye lysate was measured by a micro-lysate protection assay. The expression of AANAT mRNA in the pineal gland and the retina exhibited circadian rhythm with peak levels at night. AANAT mRNA was also detected in the testis, but did not display a rhythmic change over a 24 hr period. AANAT mRNA was not detected in other tissues studied. Darkness during the day did not increase the pineal AANAT mRNA levels. However, unexpected light-exposure for 2 hr just after lights-off blocked the increase in AANAT mRNA, and at midnight remarkably decreased AANAT mRNA by 50%.

Regulation of the expression of serotonin N-acetyltransferase gene in Japanese quail (Coturnix japonica): II. Effect of vitamin A deficiency

Levels of serotonin N-acetyltransferase [arylalkylamine N-acetyltransferase (AANAT); EC2.3.1.87] mRNA, AANAT activity, and melatonin display a rhythmic pattern in both the pineal gland and the retina. It has been shown that vitamin A is required to maintain the rhythm of melatonin synthesis in the pineal gland of Japanese quail. To understand the mechanism underlying the direct relationship among these factors, we developed an assay system sensitive enough to determine AANAT mRNA, AANAT activity, and melatonin content from a single pineal gland of Japanese quail. Positive direct relationships were found among these three parameters. We next deprived Japanese quail of vitamin A by feeding them a vitamin A-free diet supplemented with retinoic acid, and examined the effects of vitamin A deficiency on the expression of AANAT mRNA in the pineal gland and the retina. Vitamin A deficiency reduced both the expression of AANAT mRNA and melatonin content in the pineal gland. Retinal AANAT mRNA rhythm disappeared in vitamin A-deficient quails. Moreover, the responsiveness of the pineal gland and the retina to light was reduced by vitamin A deficiency when compared with the control group.

Effect of benzene, toluene, xylene on the semen quality of exposed workers

OBJECTIVE

To examine the effects on semen and sperm quality of workers after a short and long term exposure to benzene, toluene, and xylene.

METHODS

The semen and blood of 24 married workers exposed to benzene, toluene, and xylene from shoemaking, spray painting, or paint manufacturing factories were collected. The concentration of benzene, toluene, and xylene in the blood and semen was determined by using headspace chromatographic method. Routine sperm test was carried out and acrosin activity detected.

RESULTS

The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers in a working environment where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). This result was not found in workers of the control group. There were also some effects on the quality of semen in the exposed workers. For example, the percentage of semen with liquefaction time exceeding 30 minutes increased. The sperm vitality, motility and acrosin activity decreased. At the same time, there were a positive correlation between liquefaction time and the level of toluene in semen, and a negative correlation between sperm vitality, sperm activity or acrosin activity and working history.

CONCLUSIONS

The results suggested that the mixture could affect the quality of semen and sperm, which might be the main reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene. Further studies are, however, required to confirm these findings.

Waveguide-hologram-based wavelength-multiplexed pseudoanalog true-time-delay module for wideband phased-array antennas

A pseudoanalog true-time-delay (TTD) module based on substrate-guided waves and wavelength-division multiplexing is presented. A 1-to-32 (5-bit) even fan-out is demonstrated by use of a two-dimensional waveguide hologram array. This module has a packing density of 2.5 lines/cm(2) and very compact packaging (8 cm x 4 cm x 8 mm). It also reduces TTD system complexity by providing continuously tuned delay signals to parallel-control the whole phased-array antenna system. The device has a measured bandwidth of as high as 2.4 THz. The delay signal can range from tens of picoseconds to several nanoseconds.

[A methodological study on the evaluation of insulin resistance in vivo]

OBJECTIVE

To investigate the advantage and disadvantage of several methods often used to evaluate insulin resistance and to attempt to modify the disadvantage.

METHODS

Three protocols of minimal model technique (MMT), three protocols of basal state approach and four protocols of oral glucose tolerance test (OGTT) were used respectively to calculate insulin sensitivity index (ISI) in 16 subjects with normal glucose tolerance (NGT) and 13 patients with non-insulin-dependent diabetes mellitus (NIDDM). ISI of classical MMT was regarded as standard; ISI of other protocols were analyzed, assessed and compared with that of classical MMT.

RESULTS

Except the ISI expressed by the ratio of fasting serum glucose to insulin concentration (FSG/FIns) and the ratio between area under curve (AUC) of glucose and insulin (AUCg/AUCi) in OGTT, ISI of other protocols was significantly higher in NGT group than in NIDDM group (P < 0.05, ISI relative values were 1 and 0.44 - 0.70 respectively) and had stronger relationships as compared with ISI of classical MMT (r = 0.45 - 0.92, P < 0.05).

CONCLUSION

The modifications that reduce the samples to 12 or 10 and shorten the time to 120 min for MMT are feasible. Both the homeostasis model assessment and the basal state method designed by LI Guangwei are very simple; they can roughly evaluate insulin sensitivity. OGTT designed by Cederholm is a relatively simple and precise method of measuring IR. Two protocols of OGTT designed by the authors may be accurate methods for evaluating IR. Both FSG/FIns and AUCg/AUCi can not reliably evaluate insulin sensitivity.

[Expression of Schistosoma japonicun fatty acid binding protein gene in silkworm cells and larvae]

AIM

To express the fatty acid binding protein (Sj14FABP) gene of Schistosoma japonicun in the silkworm cells and larvae.

METHODS

A 600 bp DNA fragment containing Sj14FABP gene was cloned into baculovirus transfer vector of pBacPAK His1 to construct recombinant transfer vector Sj14-pBac PAK His1. Coinfection was accomplished with this vector and Bombyx mori nuclear polyhedrosis virus (BmNPV) DNA in BmN cells. The recombinant virus of Bm-Sj14 was screened using dot-blotting. The BmN cells and silkworm larvae were infected with Bm-Sj14 to express Sj14FABF gene. Western blotting and ELISA were used to identify the antigenicity of the recombinant protein.

RESULTS

Sj14FABP gene was successfully expressed in the BmN cells and silkworm larvae infected with Bm-Sj14. The product was a 18 kDa fusion protein. The yield in BmN cells was about 100 micrograms/1 x 10(6) cells and 33 micrograms/ml cell supernatant. In silkworm larvae, the product yield was 4 mg/ml haemolymph as well as 4.6 mg/g silkworm tissue. The recombinant protein could be recognized by Western blotting and ELISA using the sera from mice immunized with SWAP.

CONCLUSION

Sj14FABP gene has been successfully expressed in BmNPV system and the product has high antigenicity.

[Relationship of polymorphism of LMP2 gene to insulin-dependent diabetes mellitus and DR3 gene]

OBJECTIVE

To investigate the relationship of polymorphism of large multifunctional protease (LMP) 2 genes to insulin-dependent diabetes mellitus (IDDM) and DR3 gene.

METHODS

The polymorphism of LMP2 genes was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 68 IDDM patients and 71 healthy controls. IDDM patients and healthy controls were respectively divided into 2 groups according to DR3 genotyping. One group included subjects with DR3 gene, and another group subjects without DR3 gene.

RESULTS

In the subjects with DR3 gene, the frequencies of LMP2-R/H, LMP2-R/R, LMP2-H/H were 47%, 47% and 6% in the IDDM patients, 13%, 87%, 0% in the controls. Compared with the Controls, the IDDM patients had a higher frequency of LMP2-R/H (P < 0.05) and a lower frequency of LMP2-R/R (P < 0.05). In the subjects without DR3 gene, the frequencies of LMP2-R/H, LMP2-R/R, LMP2-H/H were 58%, 39%, 2.8% respectively in the IDDM patients, and 32%, 54%, 14% respectively in the controls. Compared with the controls, the IDDM patients had a higher frequency of LMP2-R/H (P < 0.05), the frequency of LMP2-R/R in the IDDM patients did not have a significant difference from that in the controls (P > 0.05).

CONCLUSIONS

There may be a significant association of LMP2-R/H and LMP2-R/R with the susceptibility to IDDM. The LMP2-R/H is a susceptible gene. The people with LMP2-R/H have a higher risk of suffering from IDDM. The LMP2-R/R is a protective gene. The people with LMP2-R/R have a decreased risk of suffering from IDDM. The effects of LMP2 on ID-DM are not affected by DR3 gene.

Alveolar hypoxia increases gene expression of extracellular matrix proteins and platelet-derived growth factor-B in lung parenchyma

The walls of pulmonary capillaries are extremely thin, and wall stress increases greatly when capillary pressure rises. Alveolar hypoxia causes pulmonary vasoconstriction and hypertension, and if this is uneven, some capillaries may be exposed to high transmural pressure and develop stress failure. There is evidence that increased wall stress causes capillary remodeling. In this study we exposed Madison strain Sprague-Dawley rats to normobaric hypoxia (10% oxygen) for 6 h or 3 d (short-term group), and for 3 d or 10 d (long-term group). Peripheral lung tissue was then collected and messenger RNA (mRNA) levels were determined for extracellular matrix (ECM) proteins and growth factors. Collagen content (hydroxyproline) was also measured. Levels of mRNA for alpha2(IV) procollagen increased sixfold after 6 h of hypoxia and sevenfold after 3 d of hypoxia, and then decreased after 10 d exposure. Levels of mRNA for platelet-derived growth factor-B (PDGF-B) doubled after 6 h of hypoxia but returned to control values after 3 d. mRNA levels for alpha1(I) and alpha1(III) procollagens and fibronectin were increased after 3 d of hypoxia (by seven- to 12-fold, 1.6- to eightfold, and 12-fold, respectively), then decreased toward control values after 10 d. In contrast, neither levels of mRNA for vascular endothelial growth factor (VEGF) nor collagen content changed. These results suggest that alveolar hypoxia causes vascular remodeling in lung parenchyma, and are consistent with capillary wall remodeling in response to increased wall stress.

[Hyaluronic acid and laminin in patients with ischemic necrosis of femoral head]

To study the course and clinical significance of hyaluronic acid (HA) and laminin(LN), the main components of extracellular matrix in ischemic necrosis of femoral head(INFH), the quantities of HA and LN were measured by radioimmunoassay in 45 patients suffering from INFH with different pathogenesis, and in 30 normal subjects(NS). The results showed that the level of HA in patients with INFH was markedly higher than that of NS group(t = 3.29, P < 0.01). The patients with hormone type INFH had the highest level of HA(t = 3.62, P < 0.01). The level of LN in patient with INFH was significantly higher than that of NS group(t = 2.84, P < 0.01). The increased levels of HA and LN were positively correlated with the development of the disease. These suggest that quantity analysis of HA and LN may be used as a good indicator in early diagnosis and prognosis of INFH.

Contribution of the absence of aspartic acid at position 57 of the HLA-DQ beta chain to predisposition to insulin-dependent diabetes mellitus in a southern Chinese population

OBJECTIVE

To investigate the association of the absence or presence of aspartic acid at position 57 of the HLA-DQ beta chain (NA or A) with susceptibility or resistance to insulin-dependent diabetes mellitus (IDDM) in a Southern Chinese population.

METHODS

Sixty-nine IDDM patients and 47 healthy controls in a Southern Chinese population were HLA-DQB1 genotyped by one-step sequence specific polymerase chain reaction (ssPCR).

RESULTS

The frequencies of NA and A were 64.5% and 35.5% in the IDDM patients, and 40.4% and 59.6% in the control subjects respectively (RR for NA was 2.68, P < 0.01). The frequencies of NA/NA, NA/A and A/A phenotypes were 47.8%, 33.3% and 18.8% in the IDDM patients, and 31.9%, 17.0% and 51.1% in the controls respectively (P < 0.01). The frequency of A/A phenotype was significantly lower in the IDDM patients than in the control subjects (RR = 0.22, P < 0.01). DQB1* 0302 and DQB1* 0201 were more frequent in IDDM patients than in control subjects. The younger the age of IDDM onset, the higher the allele frequencies of DQB1* 0201 and DQB1* 0302.

CONCLUSION

The present study suggests that the NA confers the susceptibility to IDDM, while the A confers the protection against IDDM in patients of Southern Chinese origin. These associations are more clearcut in childhood-onset IDDM patients.

Tca1, the retrotransposon-like element of Candida albicans, is a degenerate and inactive element

Candida albicans is an asexual fungus and as such must rely on mechanisms other than sexual recombination to generate genetic diversity. Retrotransposons are ubiquitous genetic elements known to generate multiple types of genomic alterations. We have further investigated the nature of the retrotransposon-like element Tca1 in C. albicans. Tca1 is present at two loci in strain SC5314. Both loci have now been cloned, and one element was sequenced in its entirety. This element was flanked by alpha elements, or long terminal repeats (LTRs), and contained an intervening region of 5,614 bp. The intervening region was highly degenerate and contained no extended open reading frames, indicating that Tca1 is not a functional element. Partial sequence determination demonstrated that the elements from the two loci were nearly identical. Genetic manipulation of the elements showed that both loci were heterozygous for Tca1, that both were transcriptionally active, and that deletion of both had no effect on growth rate or germ tube formation. Thus, it is unclear why this nonfunctional, highly degenerate element has been maintained in many clinical isolates.

[The transcriptional regulation of the TCA1 elements and their effects on morphogenesis of Candida albicans]

We have cloned two copies of retrotransposon-like elements Tca1-1 and Tca1-2 (Transposon Candida albicans) from Candida albicans strain SC5314. Comparing the restriction maps of the two genomic fragments, similar patterns were observed. The two composite elements were transcribed into an approximately unit length 6 kb RNA. The expression of this transcript was greatly increased when cells were grown at 25 degrees C versus 37 degrees C. Deletion of the partial or complete intervening region of the Tca1-1 element causes the morphogenetic variation of the cells. The morphogenetic variation is in cooperation with the expression of the URA3 gene.

Successful transplantation of porcine livers after warm ischemic insult in situ and cold preservation including postconditioning with gaseous oxygen

BACKGROUND

In order to reduce the shortage of viable donor livers for organ transplantation, a method has been developed that allows even predamaged livers from nonheartbeating donors to be used as transplantable organs.

METHODS

Porcine livers were harvested 45 min after cardiac arrest of the nonheparinized donor, preflushed with heparinized saline solution, and subsequently rinsed with University of Wisconsin solution, to which superoxide dismutase was added as an oxygen free radical scavenger. Thereafter, the livers were persufflated with gaseous oxygen via the venous vascular system while immersed in University of Wisconsin solution at 4 degrees C for 4 to 5 hr.

RESULTS

After orthotopic transplantation, all of the livers conditioned with gaseous oxygen were able to support life-sustaining function during the whole observation period of 7 days post transplantation, while no survival of the recipients could be obtained without the described treatment.

CONCLUSIONS

The present study establishes a new perspective for the use of ischemically altered livers from nonheartbeating donors for organ transplantation under clinical circumstances.

Compact broadband 5-bit photonic true-time-delay module for phased-array antennas

Photonic true-time-delay (TTD) lines offer many advantages over their electronic counterparts and are attracting more and more research effort. We demonstrate a device with 32 TTD lines (5-bit) based on substrate guided-wave propagation combined with slanted photopolymer volume phase gratings on a quartz substrate. System design, device fabrication, optimization of fan-out intensity uniformity, and device performance evaluation are addressed as well. The device has a measured bandwidth of up to 2.4 THz and a measured fan-out delay step of 50 ps. The fan-out beam intensity uniformity is within +/-10% . The packing density is 2.5 delay lines/cm(2), which is to our knowledge the highest demonstrated thus far.

Protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in streptozotocin-induced diabetic rats

OBJECTIVES

To evaluate the protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in rats with experimentally induced diabetes and explore its possible mechanisms.

METHODS

Ninety-two adult male Wistar rats were randomly allocated into diabetes mellitus (DM), diabetes mellitus + perindopril (DMP) and control (C) groups. According to the duration of diabetes or observation (1, 3, 6 months), each group was randomly subdivided into DM1, DM3, DM6; DMP1, DMP3, DMP6; and C1, C3, C6 groups. Diabetes was induced by intraperitoneal injection of streptozotocin. The rats in the DMP groups received perindopril 1 mg.kg-1.d-1, through gastric intubation. Urinary protein excretion rate was determined by the method of Coomassie brilliant blue. Plasma renin activity, renal tissue renin activity, and plasma and renal tissue angiotensin II concentration were assayed by radioimmunoassay (RIA). Renal tissue total RNA was extracted by the Chomezymskis AGPC method. Renal angiotensinogen mRNA expression level was assessed by slot blot hybridization using a full length rat angiotensinogen cDNA probe labelled with 32P-dCTP and a random primer.

RESULTS

There was increased activity of the renin angiotensin system in diabetic rats. Perindopril decreased proteinuria and delayed the progression of glomerular basement membrane thickening. However, it did not reduce the expansion of the mesangial matrix (P < 0.05). Renin activity increased and angiotensin II concentration decreased significantly in both plasma and renal tissue in diabetes + perindopril groups (P < 0.05).

CONCLUSIONS

Perindopril may help prevent the progression of diabetic glomerulopathy, and the inhibition of renin angiotensin system activity may be a mechanism for this action.

Segmental defect of the intestinal musculature associated with ileal atresia and biliary atresia

A full-term baby boy with a segmental defect of the ileal musculature associated with terminal ileal and biliary atresia is presented. The newborn had a dilated loop of the ileum 30 cm proximal to the ileal atretic site. Pathological study results showed absence of the intestinal musculature with relatively intact mucosa. Foci of recent muscular necrosis were found in the lesion. One month later, relaparotomy was performed because of persistent jaundice and hepatic duct atresia was confirmed. Segmental defect of the intestinal musculature associated with ileal atresia and biliary atresia has not been reported in the literature. The authors emphasize that in the management of this unusual defect, one should pay attention to the multiple associated malformations.

Vitamin A deficiency reduces the responsiveness of pineal gland to light in Japanese quail (Coturnix japonica)

Synthesis of melatonin in pineal gland is under the control of light environment. The recent finding of the presence of rhodopsin-like photopigment (pinopsin) and retinal in the avian pinealocytes has led to a hypothesis that vitamin A is involved in photoresponses of the pineal gland. We have thus analyzed the effect of vitamin A deficiency on the regulatory system of melatonin synthesis in the pineal gland of Japanese quail. Depletion of vitamin A from Japanese quails was attained by feeding them with a vitamin A-free diet supplemented with retinoic acid. In the vitamin A-deficient birds, diurnal rhythm in melatonin production persisted such that the phase of the wave was similar to that seen in the control birds. However, the amplitude of the nighttime surge of pineal melatonin was damped by vitamin A deficiency. When the control birds were briefly exposed to light at night, pineal melatonin dropped to the daytime level. In contrast, only slight decrease was observed in the vitamin A-deficient quails. The light responsiveness was restored after feeding the vitamin A-deficient quails with the control diet for 1 week. These results indicate that vitamin A plays essential roles in maintaining sufficient responsiveness of the avian pineal gland to photic input.