Determinants of lethality from suicidal pesticide poisoning in metropolitan HsinChu

Acute pesticide poisoning is a global health problem, especially in developing countries. Although Taiwan has quickly industrialized during the last several decades, pesticide use is still prevalent in the agricultural sector. We reviewed 187 consecutive hospitalized cases of the Provincial HsinChu Hospital from January 1989 through December 1995 to explore the determinants of acute pesticide poisoning in Metropolitan HsinChu. The annual incidence rate of acute pesticide poisoning was 3.2/100,000 with an overall fatality rate of 23% which was more severe than the rates found in developed countries. The major agents involved were organophosphates, and the major cause of poisoning was suicide. Alcohol abuse, history of major medical illnesses, and history of suicide were significantly associated with suicidal poisoning; quarrel was the immediate risk factor. Causes of poisoning (suicide vs non-suicide) and selection of the pesticides were major determinants of lethality. More stringent legislation and enforcement regarding the sale and distribution of extremely toxic pesticides are needed to reduce fatalities due to acute pesticide poisoning.

The role of free radicals and membrane lipids in diabetes-induced congenital malformations

OBJECTIVE

The incidence of major congenital malformations is approximately 6-9% in pregnancies complicated by diabetes mellitus. This incidence is 3-4-fold higher than that in the general population. Congenital malformations are now ranked as the leading cause of death in the offspring of women with diabetes. The precise mechanism(s) by which these anomalies are induced is unknown. It is also not clear what predisposes women to deliver malformed infants, which infants are at risk, and why some are spared even when exposed to presumably high risk conditions. The purpose of this report is to determine, from the literature, the primary etiologic factors associated with diabetes-induced embryopathy and its prevention.

METHODS

A review of the current literature regarding malformations in diabetic pregnancies was conducted to elucidate dominant concepts in the pathogenic mechanism(s) of these anomalies and to discuss current and future strategies for their prevention.

RESULTS

Numerous investigators have demonstrated that hyperglycemia has a teratogenic effect during organogenesis. However, the exact mechanisms involved have not been completely elucidated. Dietary supplementation of deficient substrates (arachidonic acid or myo-inositol), either in vitro or in vivo, has been shown to reduce the incidence of diabetes-related malformations in offspring of diabetic pregnant animals. In addition, free oxygen radical-scavenging enzymes and antioxidants aimed at reducing the excess load of radicals also result in a reduced malformation rate. Clinical evidence has demonstrated that the teratogenic effects of hyperglycemia may be obviated by maintaining euglycemia throughout organogenesis. Numerous studies have demonstrated that participation in a preconception care program can reduce the incidence of malformations in women with diabetes to the background rate. Unfortunately, less than 10% of women with diabetes currently enter these programs.

CONCLUSIONS

Diabetic embryopathy remains the single most common lethal problem affecting diabetic pregnancies today. Although preconception planning and glycemic control can reduce the incidence of malformations, it is often difficult to get women to attend such programs and to achieve and maintain euglycemia. The use of dietary supplements, which presumably would override the teratogenic effects of aberrant metabolic fuels, holds great promise for the future as a prophylaxis against diabetic embryopathy.

Dietary myo-inositol therapy in hyperglycemia-induced embryopathy

Dysmorphogenesis in diabetic mothers occurs more frequently than in the general population. This phenomenon is believed to be caused by the teratogenic effects of metabolic fuel mixtures with associated membrane injury and aberrations in the biochemical constituents. The present experiment was designed to determine: 1) if hyperglycemia-induced membrane injury is associated with intracellular and/or extracellular lipid disturbances; 2) if supplemental myo-inositol therapy prevents hyperglycemia-induced embryopathy; 3) if a correlation exists between dietary myo-inositol, serum and tissue levels of myo-inositol, and conceptus development; and 4) the cellular content of arachidonic acid following myo-inositol supplementation. Sixty-five female Sprague-Dawley rats were mated, and divided into three groups. One group was nondiabetic normal controls, and two groups had diabetes experimentally induced with streptozotocin. Of the diabetic groups, one received a normal diet, while the other received a myo-inositol-supplemented diet during the period of organogenesis. Blood samples were collected on days 0 and 12 of pregnancy. Embryos and yolk sacs were analyzed for myo-inositol and arachidonic acid levels, using mass spectrochromatography. Dietary myo-inositol supplementation of diabetic mothers resulted in a significant decrease in the incidence of neural tube defects when compared with diabetics not receiving supplements (9.5 vs. 20.4%; P < 0.05). This protective effect was incomplete, based on the incidence observed in the nondiabetic controls (9.5 vs. 3.8%; P < 0.05). The myo-inositol embryonic tissue levels in the diabetic group which had been fed a regular diet without supplementation were significantly lower than in the nondiabetic group. Dietary therapy successfully restored myo-inositol levels in the yolk sacs, as suggested by similar tissue levels in diabetics receiving myo-inositol supplementation and normal controls (18.7 +/- 1.3 vs. 19.1 +/- 2.0 ng/mg; P = ns). Dietary therapy, however, failed to restore myo-inositol levels in the embryos, suggesting hyperglycemia-induced faulty transport of nutrients from the yolk sac to the embryo. No correlation was noted between maternal blood levels of myo-inositol, with or without supplementation, and the clinical outcome. Tissue arachidonic acid levels were markedly reduced in the conceptuses of diabetic mothers with (0.4 +/- 0.1 micrograms/mg) or without (0.25 +/- 0.08 micrograms/mg) myo-inositol supplementation when compared to the nondiabetic controls (3.33 +/- 0.24 micrograms/mg). These data demonstrate that diabetes-induced embryopathy is associated with a deficiency state in both myo-inositol and arachidonic acid. The myo-inositol deficiency is not demonstrated at the serum level, but rather at the tissue level, suggesting a paracrine action. Dietary supplementation of myo-inositol is associated with an increase in tissue myo-inositol levels and a decrease in malformations. This therapy holds promise for use as a dietary prophylaxis against diabetic embryopathy.

Microstructure investigations of ball milled materials

HREM and FEG TEM were emphasized and extensively used to follow the most subtle changes in the structure and composition of ball-milled Cu, Fe-Cu, and thermally decomposed Fe60Cu40. Some significant results are obtained and summarized as follows: HREM shows that the deformation of ball-milled copper proceeds mainly by twinning and shear bands (SBs) formation. The nano-grains formed during ball milling (BM) contain a high density of dislocations. The grain boundaries (GBs) of nanocrystalline (NC) Cu prepared by BM are ordered, curved, and strained, but disordering, lattice distortion, and nanovoids in local regions were frequently observed. Nanoscale composition analysis on mechanically alloyed Fe16Cu84 shows that the average Fe content in both the interior of grains and the GBs is close to the designed composition, which proves that a supersaturated solid solution has really formed. However, the Fe content is rather inhomogeneous between the larger and smaller grains, which infers the inhomogeneous mixing of Fe and Cu during mechanical alloying (MA). NC structure and the mechanical force-enhanced fast diffusion are the reasons of the formation of supersaturated solid solutions in immiscible systems with positive enthalpy of mixing. HREM observations carried out with the thermally decomposed Fe60Cu40 solid solution show that the Nishiyama (N-W) or Kurdyumov-Sachs (K-S) orientation relationships exist between alpha-Fe and Cu. Energy dispersive X-ray spectra (EDXS) results show that the Cu content in these alpha-Fe grains reaches as high as 9.5 at.% even after heating to 1,400 degrees C, which is even higher than the maximum solubility of Cu in gamma-Fe at 1,094 degrees C.

Free radical scavenging enzymes in fetal dysmorphogenesis among offspring of diabetic rats

Recent studies have suggested that the fetal dysmorphogenesis in diabetic pregnancies is associated with an increase in embryonic oxygen-free radicals. This excess of oxygen-free radicals may result from either overproduction or decreased clearance by the enzymatic scavenging mechanism. However, there are no in vivo data on the activity of embryonic oxygen-free radical scavenging enzymes. The purpose of the current study is to investigate whether this increase in embryonic oxygen-free radicals is the result of a change in the activity of the fetal oxygen-free radical scavenging/antioxidant enzymes during pregnancy complicated by maternal diabetes in an in vivo rat model. Thirty-six Sprague-Dawley rats were randomly assigned to one of two study groups: nondiabetic control and an untreated diabetic group. On day 12, fetuses were examined for crown-rump lengths, somite numbers, and external anomalies. The activity of fetal oxygen-free radical scavenging enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT), were determined. The untreated diabetic group of rats had a significantly higher mean blood glucose level than that of the nondiabetic controls and also a significantly lower weight gain, higher resorption rate, smaller embryonic size with lower total protein content, and a approximately 6-fold increase in the rate of fetal neural tube defects compared to the nondiabetic controls. Superoxide dismutase activity was significantly reduced in the embryos with neural tube defects regardless of maternal diabetic status (2.25 +/- 0.83 vs. 1.17 +/- 0.04 u/mg protein; P < 0.05). Glutathione peroxidase and catalase activity were significantly reduced in malformed versus normal-formed embryos of nondiabetic mothers (GPX-2.68 +/- 1.15 vs. 4.46 +/- 1.12 mu/mg protein, CAT -1.67 +/- 0.53 vs 2.49 +/- 0.61 u/mg protein respectively; P < 0.01). However, overall catalase activity was increased in embryos of diabetic mothers as compared to controls. Two-way analysis of variance identified fetal malformations as the variance associated with reduced fetal SOD activity, whereas maternal diabetes was associated with the increase in fetal catalase activity. Neither neural tube defect nor maternal diabetes was found to be the variable affecting fetal GPX activity, Fetal oxygen-free radical scavenging enzymes respond differently to the adverse environment created by maternal diabetes during pregnancy. Defects in embryonic SOD and catalase activity, regardless of maternal diabetic status, may reduce the ability of the fetus to clear free oxygen radicals, thereby exposing it to an increased oxidative load that may cause fetal dysmorphogenesis. The diabetic state of the mothers did not decrease embryonic activity of any of the scavenging enzymes. Therefore, although excess oxidative load, as observed in diabetes, may cause tissue injury and embryopathy, the mechanism does not appear to be a diabetes-induced reduction in the action of the scavenging enzymes.

Prevention of diabetic embryopathy in offspring of diabetic rats with use of a cocktail of deficient substrates and an antioxidant

OBJECTIVE

The current study sought to determine whether a dietary cocktail of deficient substrates and antioxidant could reduce the incidence of diabetic embryopathy to the background rate in an in vivo rat model.

STUDY DESIGN

Sprague-Dawley rats 70 to 90 days old were assigned to one of eight groups: two control groups (groups 1 and 2) and six diabetic groups (groups 3 to 8). One group of controls (group 2) received an oral supplemental cocktail of vitamin E ((alpha-tocopherol, 400 mg/day), safflower oil (arachidonic acid, 1 ml/day), and myo-inositol 0.08 mg per day. Four other diabetic groups (groups 5 to 8) received the cocktail in varying strengths. One diabetic group (group 3) received a normal diet only without insulin or cocktail, whereas another diabetic group (group 4) received insulin but no cocktail supplementation. On day 6 of gestation diabetes was induced in groups 3 to 8 with intravenous streptozotocin (65 mg/kg), and maternal glucose levels were monitored. Animals were killed on day 12; embryos were examined for size, somite number, and evidence of malformations and were biochemically evaluated for vitamin E and myo-inositol levels and superoxide dismutase activity.

RESULTS

The diabetic groups had a significantly higher (p < 0.05) mean blood glucose level than controls did. The insulin-treated group 4 had glucose levels that were comparable to those of controls. The unsupplemented diabetic group 3 had a neural tube defect rate of 23.7% versus 4.04% in controls and 3.55% in insulin-treated diabetics (p < 0.05). The rate of neural tube defects was significantly reduced to the background level in animals receiving half-strength cocktail or stronger doses (groups 6 to 8) compared with the diabetic unsupplemented controls (group 3). Diabetic animals in group 5 receiving only quarter-strength cocktail did not demonstrate a significant reduction in the malformation rate. Serum myo-inositol levels were not significantly different among the groups. However, serum levels of vitamin E were significantly higher in diabetics receiving half-strength cocktail than in nondiabetic controls, diabetics receiving no supplements, and diabetics receiving quarter-strength cocktail. Superoxide dismutase activity was also significantly increased in diabetic animals receiving supplementation versus animals not receiving the same, and the increases in vitamin E and superoxide dismutase were significantly correlated (r = 0.66, p < 0.05).

CONCLUSION

These data demonstrate that a cocktail containing deficient substrates and an antioxidant in varying strengths reduces the malformation rate to background in offspring of diabetic rats.

Dietary intake of myo-inositol and neural tube defects in offspring of diabetic rats

OBJECTIVE

Embryopathy in diabetic mothers occurs at a rate four to five times higher than that observed in the general population. The current investigation was undertaken to assess the use of dietary myo-inositol supplementation as a pharmacologic prophylaxis to obviate the teratogenic effects of hyperglycemia in an in vivo study.

STUDY DESIGN

Seventy Sprague-Dawley rats were mated and after conception were randomly divided into five groups: one group was nondiabetic normal controls and four groups had diabetes experimentally induced with streptozotocin. Of the diabetic groups, one received the usual diet, whereas the others received, respectively, 0.08, 0.16, and 0.5 mg/day supplemental myo-inositol orally.

RESULTS

With the myo-inositol supplementation (0.08 mg/day), the incidence of neural tube defects was significantly reduced from 20.4% to 9.5% (p < 0.01). The most effective dosage of myo-inositol was 0.08 mg/day. Increasing the dose of myo-inositol beyond that level did not significantly reduce the rate of neural tube defects. However, the resorption rate was increased to 29.8%.

CONCLUSION

These data demonstrate that myo-inositol supplementation reduces the incidence of diabetic embryopathy and may serve as a pharmacologic prophylaxis against diabetes-induced congenital malformations.

Dietary vitamin E prophylaxis and diabetic embryopathy: morphologic and biochemical analysis

OBJECTIVE

In this study we sought to determine whether dietary supplementation with vitamin E, a known antioxidant, would reduce the incidence of diabetic embryopathy in an in vivo rat model.

STUDY DESIGN

Eighty-day-old Sprague-Dawley rats were assigned to one of five groups: two control groups (groups 1 and 2) and three diabetic groups (groups 3, 4, and 5). One group of controls (group 2) and one group of diabetic rats (group 4) received dietary supplements of vitamin E (440 mg/day). The other three groups (groups 1, 3, and 5) received a normal diet only. Group 5 received insulin therapy to control glucose levels. On day 6 of gestation diabetes was induced in groups 3, 4, and 5 with streptozotocin (65 mg/kg). Animals were killed on day 12; embryos were examined for size, protein content, evidence of malformations, and superoxide dismutase activity.

RESULTS

In both groups (groups 3 and 4) of diabetic rats the mean blood glucose level than was significantly higher in controls. Insulin-treated animals (group 5) had glucose levels that were comparable to those of controls. The unsupplemented diabetic group had a neural tube defect rate of 21.48% +/- 9.6% (percentage of neural tube defects per rat) and a resorption rate of 21.37% +/- 20.39% (percentage of resorptions per rat) as compared with rates in the supplemented diabetic group of 6.92% +/- 4.08% and 2.17% +/- 3.74%, respectively (p < 0.01). Groups 1, 2, and 5 had similar neural tube defect rates (6.63% +/- 5.0%, 5.01% +/- 4.87%, and 3.55% +/- 5.92%, respectively. Vitamin E levels, measured by high-performance liquid chromatography, were significantly higher in maternal serum and embryos in the supplemented groups (p < 0.001) than in controls. Superoxide dismutase activity was reduced in the diabetes groups and was not affected by vitamin E therapy.

CONCLUSIONS

Supplementation with the antioxidant vitamin E confers a significant protective effect against diabetic embryopathy and may potentially serve as a dietary prophylaxis in the future. We postulate that this protective effect is mediated by a reduction in the oxidative load induced by hyperglycemia.

Multifactorial basis of the syndrome of diabetic embryopathy

OBJECTIVE

The aim of the current paper is to explore the multifactorial basis of diabetes-induced embryopathy.

METHOD

A review of the literature regarding congenital malformations was undertaken to elucidate new advances in our understanding of diabetic embryopathy. Data from both clinical and experimental studies were collected and analyzed.

RESULTS

Numerous investigators have demonstrated that hyperglycemia and other metabolic fuels produce teratogenic effects during organogenesis. However, the exact mechanism(s) involved have not been completely elucidated. We and others have shown that aberrant metabolic fuels including hyperglycemia and hyperketonemia are teratogenic and that these effects occur via the yolk sac which appears to be the target site of injury. Other proposed etiologic factors include nutrient deficient states in membrane lipids such as arachidonic acid and myo-inositol as well as the generation of excess free oxygen radicals. This review highlights the multiple theories that have been proposed and summarizes the experimental and clinical data which support a multifactorial basis.

CONCLUSIONS

Evidence suggests that although the teratogenic process in the diabetic pregnancy is multifactorial, it may operate via a common pathway. Prevention of malformations in offspring of diabetic rats is achieved by glycemic control during organogenesis. Similar results may be obtained in a hyperglycemic state, provided there is restoration of essential fatty acid/phospholipid deficiency state and normalization of excess free radicals which may be achieved through dietary supplementation of polyunsaturated fatty acids, myoinositol, or antioxidants. The latter approach offers great promise as an adjunct to periconceptional glycemic control and as a dietary prophylaxis against the syndrome of diabetic embryopathy.

Dietary polyunsaturated fatty acid prevents malformations in offspring of diabetic rats

OBJECTIVE

The purpose of the current study was to determine whether a dietary source of arachidonic acid could serve as a pharmacologic prophylaxis to obviate the teratogenic effects of hyperglycemia.

STUDY DESIGN

Eighty-day-old Sprague-Dawley rats were mated, and after conception were randomly allocated to five groups: two groups were nondiabetic normal controls and three groups had diabetes experimentally induced with streptozocin. Of the two control groups, one was fed a normal diet (group 1) and the other group (group 2) received a normal diet and 1.0 ml of safflower oil, a polyunsaturated fatty acid known to increase serum arachidonic acid levels. In the three diabetic groups (groups 3, 4, and 5) glucose levels were allowed to remain > 350 mg/dl by withholding daily insulin therapy. Group 3 received a normal diet without supplementation; group 4 received a normal diet plus normal saline solution sham feedings, whereas group 5 received a normal diet supplemented with 1.0 ml of safflower oil. The oral agents (normal saline solution and polyunsaturated fatty acid) were administered with a tuberculin syringe.

RESULTS

Diabetic rats not receiving insulin therapy and receiving normal diets produced offspring with malformation rates of 20% compared with control rates of 4.8%. Supplemental normal saline solution or safflower oil given orally to controls did not alter the growth or malformation rates. These rates were similarly unaffected in the diabetic rats receiving oral supplementation of normal saline solution. However, with safflower oil supplementation to diabetic rats the incidence of neural tube defects was decreased from 20.0% to 7.6% (p < 0.0001). An inverse relationship was observed between the malformation rate and the serum arachidonic acid level: 17.83 (SD 5.84 micrograms/ml) in the nondiabetic controls, with a malformation rate of 4.8%, versus 14.18 (SD 2.58 micrograms/ml) in the diabetic rats, with a malformation rate of 20.0% (p < 0.05). With safflower oil supplementation serum levels of arachidonic increased from 14.18 +/- 2.58 micrograms/ml to 19.99 +/- 7.99 micrograms/ml (p < 0.05); this was associated with a concomitant decline in the malformation rate.

CONCLUSION

These data demonstrate that diabetic embryopathy is associated with a deficiency state in essential fatty acid, corroborating our previous in vitro findings. Furthermore, the use of a dietary polyunsaturated fatty acid that specifically increases arachidonic levels significantly reduced the incidence of diabetic embryopathy. These findings may serve as a basis for developing strategies of pharmacologic prophylaxis against diabetes-induced congenital malformations.

Choledochal cyst in neonates

Common bile duct cyst, or choledochal cyst is known to be an uncommon cause of neonatal jaundice. It is usually associated with distal biliary tract obstruction and presents a clinical picture that is indistinguishable from biliary atresia. We report two cases of neonatal choledochal cyst encountered from 1992 to 1994. The infants were free from perinatal insult and presented with prolonged jaundice. In both cases, antenatal ultrasonography was unremarkable. Biochemical examinations revealed elevated levels of serum transaminases, alkaline phosphatase and direct bilirubin. Abdominal sonograms disclosed a cystic mass close to the gall-bladder. Intrahepatic duct dilation was noted in one patient. Hepatobiliary scintigraphy demonstrated accumulation of the radionuclide in the porta hepatis without subsequent intestinal activity. Cystic dilatation of the common bile duct with distal obstruction was noted during surgery. Both infants underwent cyst excision with Roux-en-Y hepaticojejunostomy and cholecystectomy. Liver biopsy in one infant showed mild proliferation of the interlobular bile duct and mild portal fibrosis. The postoperative course was uneventful. We conclude that early detection and treatment of choledochal cyst in neonates are important for preventing serious complications of biliary obstruction.

Synchronization of the factors critical for diabetic teratogenesis: an in vitro model

OBJECTIVE

Our goal was to determine the relationship between critical factors and conditions such as gestational age and exposure time to elevated glucose levels in diabetic embryopathy.

STUDY DESIGN

A postimplantation rat embryo culture was used as a model for investigation. The effect of various factors on embryonic development was studied. Experiments were conducted with increasing glucose concentrations (150 to 905 mg/dl, n = 186), at various gestational ages (10 to 12 days, n = 169), and for varying durations of exposure (30 to 180 minutes, n = 169). Gross morphologic characteristics of the yolk sac and embryo were assessed.

RESULTS

Embryopathy was induced by hyperglycemia in a dose-related fashion: a 20% rate at two times control glucose concentration, almost a 50% rate at four times control, and approximately a 100% abnormality rate at more than six times control. A critical window in gestational age, days 10 to 11, and a minimum exposure time to hyperglycemia of 2 hours were necessary to induce teratogenesis.

CONCLUSIONS

Diabetic teratogenesis occurs in a dose-related fashion and requires a minimum exposure time and critical gestational age. Only synchronization of these critical conditions induces embryonic maldevelopment. Furthermore, nonsynchronized aberrant conditions may result in apparently normal embryonic development.

Image segmentation and bright contrast spot localization of the high resolution atomic image

Some basic quantitative analysis techniques of digitized high resolution atomic image are developed in this paper. We describe how to divide the atomic image into small independent areas with special structure information by the valley mesh segmentation method. The procedure is with regard to the bright contrast spot segmentation of atomic images. We suggest several ways for bright contrast spot localization in images. Calculation routines for peak detection and weighted local position average methods for this purpose are given.

[Traditional Chinese medicine and Western medicine treatment for severe intractable head injury]

38 cases of severe intractable head injuries were treated by TCM-WM treatment, the survival rate was 68.4%, which was difficult or ineffective for Western medicine treatment. The author lay emphasis on taking the following measures: (1) Place nasal feeding tube in the nose as early as possible; (2) Take Zenye Tang and Shengmai Yin as chief prescription for nourishing Yin and replenishing Qi; (3) Take large dose of citicoline, Angong Niuhuang Wan and Xuefu Zhuyu Tang to promote resuscitation; (4) When pulmonary infection was serious and antibiotic ineffective, Shashen Maidong Tang and Ditan Tang etc. could be used.

Creep of a poly(etherurethane urea) in an oxidative environment

The creep behavior of a PEUU without added stabilizers was examined in H2O2/CoCl2, an environment that simulates the biodegradation of this polymer. Creep in the control environments, air, water, and H2O2, was logarithmic with time as is characteristic of primary or viscoelastic creep. At short times, creep in H2O2/CoCl2 followed the same time dependency as creep in H2O2; however, at longer times an acceleration in the creep rate was observed. Creep in H2O2/CoCl2 was satisfactorily described by addition of a linear time term to the creep equation with an induction time, ti. The induction time was extended by stress-induced crystallization of the soft segments, but was reduced by an increase in H2O2 concentration. Oxidative degradation of the PEUU soft segments was detected by infrared and GPC analysis at times less than ti. This led to the speculation that an initial "precursor" layer was created at the surface by chain cleavage. Microcracking in a subsequent stage was postulated to be responsible for the observed effect on the creep behavior.

Gastroduodenal intussusception due to Peutz-Jeghers syndrome. A case report

An 18-year-old Chinese male was admitted to our hospital with recurrent abdominal pain, abdominal distension and intermittent non-bilious vomiting of about 2 months standing. A mildly tender mass measuring about 6 x 7 cm was present in the right upper quadrant area, and an abdominal computed tomography scan with enhancement showed a clearly encapsulated mass occupying the right side of the upper intra-abdominal area. Endoscopy revealed two huge cauliflower-like polyps and one small polyp in the stomach, and the biopsy specimens showed hyperplastic polyps. Moreover, multiple pigmentation of the buccal mucosa was also noted. The intra-abdominal mass was found to be a gastroduodenal intussusception following laparotomy. Gastroduodenal intussusception occurring secondarily to Peutz-Jegher syndrome, is a rarely documented condition. Only one case has been reported in Japan during the previous years. We report on another case, and review the literature.

Characterization of extractable species from poly(etherurethane urea) (PEUU) elastomers

Methanol extracts of four poly(etherurethane urea) (PEUU) materials were analyzed using Gel Permeation Chromatography (GPC). The additives in the materials were Santowhite powder at 1 wt% and Methacrol 2138 F at 5 wt% loading levels. One-to-two wt% of the original PEUU films was extractable with methanol. The extractables consisted of a low molecular weight (Mw) PEUU polymer, an MDI-rich oligomer, the additives Santowhite (SW) powder and Methacrol 2138 F, and aniline. The low Mw PEUU polymer had a Mw of 12,000 relative to polystyrene, and the MDI-rich oligomer had a Mw of 1000 relative to polystyrene. Quantitation of all extracted species was achieved using GPC; the use of dual-detectors on the GPC made it possible to determine the soft-to-hard composition of the PEUU extracts as a function of molecular weight.

The yolk sac theory: closing the circle on why diabetes-associated malformations occur

OBJECTIVE

The purpose of this article is to examine the role of yolk sac failure during organogenesis in the development of diabetes-associated embryopathy.

METHODS

The current literature regarding congenital malformations in diabetic pregnancies was reviewed to elucidate the precise role of the yolk sac in embryonic development and the relation between yolk sac injury and embryopathy.

RESULTS

We and others have demonstrated that hyperglycemia produces a teratogenic effect during organogenesis. In addition, we have shown that the yolk sac appears to be the target site of injury induced by hyperglycemia. We have also presented evidence that cell membrane dysfunction leads to failed vitelline vessel formation and that arachidonic acid supplementation prevents many of the morphologic and biochemical alterations observed under hyperglycemic conditions.

CONCLUSIONS

These data strongly support the teratogenic effect of hyperglycemia, the arachidonic acid deficiency state, the resultant maldevelopment of vitelline vessels, and the ability to prevent these changes by arachidonic acid supplementation. These studies have made significant inroads in explaining why diabetes-associated anomalies occur, and suggest a potential future role for prophylaxis against these organogenetic malformations using dietary polyunsaturated fatty acid supplementation.

Metabolic fuel mixtures and diabetic embryopathy

The incidence of congenital anomalies remains the major cause of morbidity and mortality among the offspring of diabetic women. Animal and human studies indicate that these malformations occur early in pregnancy and are influenced by the abnormal maternal metabolic milieu. This article reviews the recent advances in understanding the pathogenesis of diabetic embryopathy. A possible pathway to explain the various diabetic-related fuel aberration is presented.

Synthesis of a potential bifunctional mimic of transaminases

As a potential bifunctional mimic of transaminases 3,7-dimethyl-10-[3-(4- aminomethyl-5-hydroxy-6-methyl-3-pyridyl)propyl]-3,7,10- triazatricyclo[3.3.3.0(1,5)] undecane (I) has been synthesized by attaching 3,7-dimethyl-3,7,10-triazatricyclo [3.3.3.0(1,5)]undecane (II) to a pyridoxamine nucleus via an all-carbon chain. The chain length between the pyridine ring and II is restricted to three atom units so that the possibility for II to act bifunctionally during the transamination is maximized. In its protonated form, the nitrogen closest to the pyridine ring cannot deliver the proton intramolecularly to the alpha-carbon of the developing amino acid. To make the synthetic route generally applicable, introduction of the side-arm base is arranged at a later stage of the synthesis so that different di- or poly-amines can easily be used in place of II to prepare other target molecules that might possess bifunctional catalytic activity. This arrangement also greatly reduces the polarity and water-solubility of the intermediates and the purification of these compounds thus becomes much easier. The method of introducing the amino functionality at the C-4 methylene group described herein provides an alternative to that currently in use (reduction of oximes).

Regulation of potassium and magnesium effluxes by external magnesium in barnacle muscle fibres

Fluxes and flux rate constants for potassium and magnesium were measured as a function of ambient magnesium concentration in giant muscle fibres from the acorn barnacle. Experiments were carried out in the absence of both external Na and Ca (to prevent possible effects of these ions), and fibres were depleted of internal Na and Ca by soaking in Na- and Ca-free solution before each experiment. K efflux was biphasic with respect to increases in external Mg concentration [( Mg+2]0). K efflux approximately doubled (from about 63 to 130 pmol/cm2.s) when [Mg+2]0 was increased from 2 to 5 mM; K efflux remained elevated in Mg up to 60 mM. However, at [Mg+2]0 = 120 mM, the stimulatory effect of external Mg vanished, and at 357 mM it was replaced by an inhibitory effect. Mg efflux was also biphasic with respect to [Mg+2]0, and this efflux was matched at low to moderate [Mg+2]0 by Mg influx of comparable magnitude. This study suggests the possible existence of a Mg transport system that can serve variously as a Na/Mg or a Mg/Mg exchanger that may require the participation of K ions for its operation.

A monokine stimulates prostaglandin-E2 production by human amnion

The studies reported in this communication were designed to test the hypothesis that products of mononuclear cells are capable of stimulating prostaglandin E2 production by human amnion. Conditioned media obtained from peripheral blood mononuclear cells were incubated with amnion cells in primary culture. A dose dependent increase in PGE2 biosynthesis was observed in response to increasing amounts of the conditioned media. These observations suggest that mononuclear cells produce a factor(s) capable of stimulating prostaglandin production by amnion cells. The signal responsible for the increased biosynthesis of prostaglandins by human amnion associated with parturition in the setting of intraamniotic infection may be of host origin.

Amniotic fluid interleukin-1 in spontaneous labor at term

The regulatory signals responsible for the increased biosynthesis of prostaglandins during parturition have not been established. Interleukin-1 (IL-1) is capable of stimulating prostaglandin production by intrauterine tissues and is an inflammation mediator. It has been postulated as a signal for the onset of labor in the setting of intrauterine infection. A study was designed to determine if spontaneous labor at term was associated with changes in IL-1 activity in amniotic fluid. Such fluid was retrieved from 41 women in labor and from 39 women who were not in labor at term. Immunodetectable IL-1 beta was present in 22 of the 41 women in labor but in only 8 of the 39 women without labor. IL-1-like bioactivity was not different between the two groups at a dilution of 1:4, but at dilutions of 1:12, 1:36 and 1:108, amniotic fluid from women in labor had significantly higher bioactivity than that from women not in labor. A significant correlation was found between the bioassay and immunoassay results. Our data show that inhibitors of IL-1 bioactivity are present in amniotic fluid and suggest that in a subset of laboring women at term, an inflammatory reaction may play a role in triggering the onset of parturition.