Experimental intrauterine growth retardation in the rat causes a reduction of pancreatic B-cell mass, which persists into adulthood.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the possibility that intrauterine growth retardation (IUGR) causes alterations of glucose tolerance, insulin secretory response to glucose, and pancreatic B-cell growth, and if such changes may persist into adulthood. METHODS: Pregnant rats were operated on day 16 of pregnancy ad modum Wigglesworth to induce IUGR. Operated rats gave birth to viable offspring but litter size was reduced. The mothers nursed their pups, which were subsequently weaned and reared to an age of 3 months in apparent good health. RESULTS: At 1 day of age, IUGR pups were 10% lighter than control newborns whose mothers had been subjected to a sham operation. Pancreatic B-cell mass and insulin content were reduced by 35-40% in newborn IUGR offspring. Postnatal growth did not differ between IUGR and control animals of either sex and the difference in body weight at birth was not apparent from 1 week of age and onwards. Tests performed at 3 months of age could not demonstrate differences in glucose tolerance between IUGR and control animals. In females, but not in males, the peak insulin secretory response to glucose was lower in IUGR animals compared to controls. In the 3-month-old rats, B-cell mass was reduced by 40% in male and by 45% in female IUGR rats compared to controls, a reduction corresponding to a similar decrease in pancreatic insulin content (male reduction 48%, female reduction 45%). CONCLUSIONS: In the rat, IUGR causes a diminution of pancreatic B-cell mass which persists into adulthood. Normal glucose tolerance could be maintained but it is conceivable that increasing demands on insulin secretion may not be met by the reduced B-cell mass and that impaired glucose tolerance and even diabetes would hence develop.

Ultrasonography in acute appendicitis. Body mass index as selection factor for US examination.

PURPOSE: Acute appendicitis is often difficult to diagnose and a negative laparotomy rate of about 25% is common. At Danderyd Hospital we started routine US in these patients, the aim being to estimate the sensitivity and the specificity for US when compared with the body mass index (BMI) of the patient. MATERIAL AND METHODS: All patient records were examined: During a period of 6 months 142 patients over 14 years of age were investigated with US. Their height and weight were noted and the BMI was calculated. RESULTS: The sensitivity for US examination was 0.76 in patients with a BMI < 25 but only 0.37 in patients with BMI > or = 25. This difference was statistically significant. CONCLUSION: US is a good method for examination of patients with BMI less than 25 but not in patients with BMI over 25.

Reducing negative appendectomy: evaluation of ultrasonography and computer tomography in acute appendicitis.

OBJECTIVE: To study the sensitivity and the specificity for ultrasonography and computed tomography in patients with suspected appendicitis, and their value to the clinician. MAIN OUTCOME MEASURES: The negative appendectomy rate and the sensitivity and the specificity for ultrasonography and computed tomography in patients with suspected appendicitis. RESULT: The diagnostic accuracy was 88% (men 95%, women 80%). Two hundred and thirty-nine patients were examined by ultrasonography preoperatively. The sensitivity for ultrasonography was 0.82 and the specificity was 0.97. Forty-nine patients were examined by computed tomography preoperatively. The sensitivity for computer tomography was 0.88 and the specificity was 0.95. CONCLUSIONS: We conclude that ultrasound and computed tomography investigations on patients with suspected appendicitis are of great value. Computed tomography seems to have a higher sensitivity than ultrasound and a high specificity. In fertile women, where unnecessary surgery is best avoided, we believe that computed tomography investigation or ultrasound examination are better alternatives to surgical intervention.

[A high degree of accuracy is possible in the diagnosis of appendicitis. Laboratory tests, ultrasonography and computerized tomography are of great value]. / Hög träffsäkerhet kan uppnås vid appendicitdiagnostik. Laboratorieprov, ultraljudsundersökning och datortomografi är av stort värde.

Although acute appendicitis is often difficult to diagnose and negative laparotomy rates of 25 per cent are common, several options are currently available for the preoperative work-up. Careful history taking and physical examination are essential, together with analysis of inflammatory variables (C-reactive protein and white cell count). After admission, additional help is available in the form of ultrasonography and computerised tomography (CT), ultrasonography apparently being best in slender and normal weight patients (body mass indices < 25) and CT in overweight patients. The article reports how, without using invasive laparoscopy, a negative laparotomy rate of 7.2 per cent (11% in women and 4% in men) was obtained in 1998 at a hospital serving a population of 330,000.

Diagnostic accuracy in 2,351 patients undergoing appendicectomy for suspected acute appendicitis: A retrospective study 1986-1993.

AIMS: To investigate the pre-operative findings, accuracy, perforation rate and complication rate in 2,351 patients who underwent appendicectomy during 1986-1993. METHOD: The 2,351 records from patients who underwent surgery were analysed to determine whether the pre-operative investigations introduced can improve the diagnostic accuracy when analysed in total. RESULTS: The total diagnostic accuracy which was 70.9% in 1986 increased to a statistically significant figure of 87.1% in 1993. In female patients, the figure increased from 61.7 to 82.4% and in males from 82.0 to 91.2% during the studied period. The complication rate was in total 10.4% including a mortality of 0.21% (5 patients). CONCLUSION: We believe that with a combination of increased interest in patients with acute appendicitis, a wider use of active in-hospital observation, a more standardised pre-operative laboratory investigation and the use of ultrasonography, a high diagnostic accuracy could be reached without an increased rate of complications and perforations.

Acute appendicitis in the elderly. An analysis of 47 patients over 80 years of age.

OBJECTIVE: To correlate the preoperative findings, perforation rate and the mortality rate after appendicectomy in the elderly age. DESIGN: Retrospective study. SETTING: Teaching hospital, Sweden. SUBJECTS: Forty-seven patients over 80 years of age who have undergone acute appendicectomy. MAIN OUTCOME MEASURES: Operative and postoperative outcome after acute appendicectomy in the elderly. RESULTS: The complication rate after appendicectomy was statistically significantly increased to 28% as well as the mortality increased to 8.5% in the elderly patients when compared to the other age group. The perforation rate was also statistically significantly increased to 64% when compared to the same group. CONCLUSIONS: Our study shows that at the time of clinical symptoms, inflammatory parameters in acute appendicitis in the elderly do not differ from the young patient, but patients older than 80 years of age have a high risk of perforation, morbidity and mortality.

Treatment of perforated appendicitis: an analysis of 362 patients treated during 8 years.

BACKGROUND AND METHOD: In a retrospective study 2,351 records from patients who underwent surgery for acute appendicitis during 1986-1993 were analysed. During this period, there were 362 patients with perforated appendicitis. The aim of this study was to analyse the complication rate, the period of antibiotic treatment and whether the complication rate decreased when intravenous treatment was followed by oral antibiotic treatment. RESULTS: The complication frequency was 18% which was significantly higher than that for non-perforated appendicitis of 10%. The complication rate was 15% in the group receiving additional oral antibiotics compared to 19% in the group receiving only intravenous antibiotics. This difference is not significant. CONCLUSION: Perforated appendicitis is however still associated with increased mortality and morbidity.

Interval appendicectomy: a retrospective study.

OBJECTIVE: To investigate the complication rate after open interval appendicectomy and compare it with the complication rate after acute appendicectomy. DESIGN: Retrospective study. SETTING: Teaching hospital, Sweden. SUBJECTS: 38 patients with appendiceal abscess or chronic appendicitis who underwent interval appendicectomy. MAIN OUTCOME MEASURES: Operative and histological findings, and postoperative complications after interval appendicectomy. RESULTS: The reasons for interval appendicectomy were appendiceal abscess (n = 32, verified by ultrasonography in 25 cases), chronic appendicitis (n = 4), and previous acute appendicitis (n = 2). Five patients underwent drainage of the abscess during the acute episode. The median interval between first symptoms of appendicitis and interval appendicectomy was 3.5 months (range 1.5-15). In two patients (5%) there were no macroscopic or microscopic signs of previous appendicitis and in one patient (61 years old) an adenocarcinoma was found in the base of the appendix. The complication rate was 13% (5/38), which is similar to our morbidity after acute appendicectomy (244/2352, 10%). CONCLUSIONS: Interval appendicectomy has the same complication rate as acute appendicectomy, and is hardly ever done. We no longer recommend it as a routine and it should be done only for special indications such as persisting complaints that suggest appendicitis.

Retrospective analysis of the efficacy of cefotaxime sodium dosed twice daily. The Swedish experience.

In a Swedish multicenter, comparative, retrospective study, patients with different types of infections--bacteremia-septicemia, genitourinary, intra-abdominal, central nervous system, and lower respiratory tract infections--were randomly selected from the hospital records. Patients treated with cefotaxime twice or three times a day as monotherapy (excluding metronidazole) for at least 1 day (240 cases) were analyzed in terms of clinical and bacteriologic outcome, these results were correlated with the dosing regimen. Similarly high success rates (cure and improvement) at hospital discharge were observed in both group initially treated with cefotaxime 1 g twice daily and 2 g twice daily (97 and 96%, respectively). A total of 73% of patients were initially treated with cefotaxime for only 3 days at most before changing to a lower dose regimen, an alternate intravenous treatment, or oral drug follow-up. Clinical evaluation at hospital discharge revealed a clinical success rate between 87 and 100%, depending on the type of infection.

Correlations between maternal metabolism and deranged development in the offspring of normal and diabetic rats.

In an attempt to define the pathogenesis of congenital malformations in diabetic pregnancy, a number of serum factors were determined in normal and diabetic pregnant rats and correlated to the outcome of gestation with the aid of multivariate linear regression analysis. The animals were from two different lines of Sprague-Dawley rats with documented differences in rates of fetal dysmorphogenesis in diabetic pregnancy. The diabetic rats increased less in body weight than the normal rats, yet displayed increased liver and kidney weights. The serum concentrations of glucose, beta-hydroxybutyrate, triglycerides, the branched-chain amino acids, and asparagine, proline, alanine, citrulline, tyrosine, and ornithine were increased by diabetes. In contrast, IGF-I, glutamic acid, glutamine, cystine, and lysine were decreased in the serum of the diabetic pregnant rats. The maternal metabolic imbalance exerted profound effects on embryonic development. Thus, the embryos of the diabetic rats were smaller, had fewer somites, and contained less DNA and protein than the control embryos. In addition, the resorption and malformation rates were increased in the embryos of the diabetic rats. The regression analysis of the data revealed significant interrelationships between adverse embryonic outcome (rates of malformations and resorptions) and the maternal serum concentrations of glucose, triglycerides, beta-hydroxybutyrate, branched-chain amino acids, and creatinine. This suggests that the maternal metabolism of the three major classes of nutrients covariates with the embryonic development in diabetic rat pregnancy. The monitoring of only one of these maternal parameters, e.g. the serum glucose concentration, may therefore not adequately predict the developmental status of the offspring. Our results suggest that the pathogenesis of fetal malformations in diabetic pregnancy is multifactorial. Thus, maintaining metabolites from all nutrient classes at a normal level may be important in preventing adverse fetal outcome.

Development of rat embryos in culture media containing different concentrations of normal and diabetic rat serum.

In vitro culture of rodent embryos has been extensively used in the search for teratologic agents, with possible relevance to diabetic pregnancy. However, the high concentrations of rat serum added to the culture medium (approximately 75%) have raised concern that the teratogenic effects of some compounds may be attenuated or masked in this culture system and thereby forced the addition of pharmacological concentrations of the compounds (e.g., D-glucose and beta-hydroxybutyrate) to the medium. This issue has been examined in the present study where the effects of different concentrations of rat serum on growth and differentiation of rat embryos were recorded in cultures supplemented with increased concentrations of D-glucose and beta-hydroxybutyrate. The embryonic development was also evaluated after culture in medium supplied with serum from diabetic rats. Compared with normal rat serum, the diabetic serum had an elevated glucose concentration as well as markedly increased levels of triglycerides and branched amino acids, indicating a potentially rich supply of major nutrients for the cultured embryos. Lowering the serum concentration in the culture medium from 80% to 50% yielded progressively retarded embryonic growth but no increased rate of other morphological malformations. At 40% serum concentration, however, there was a sharp rise in the incidence of somatic malformations, in addition to the prevailing growth retardation. When the embryonic growth and development were compared at 50% and 80% serum concentrations, increased D-glucose or beta-hydroxybutyrate concentrations caused similar degrees of embryonic dysmorphogenesis. Also, the uptake of each compound by the embryos exposed to elevated levels of the two agents were similar in 50% and 80% serum cultures. There was, therefore, no protection against the teratogenic and growth-retarding effects of increased D-glucose or beta-hydroxybutyrate offered by high serum concentrations in the culture medium (i.e., 80% vs. 50%). Embryos cultured in 50% or 80% diabetic rat serum at 30 mmol/L or 50 mmol/L D-glucose concentration showed similar rates of somatic malformations as did embryos exposed to the same proportion of normal rat serum at similar glucose concentrations. By contrast, the diabetic rat serum amplified the general retarding effects of high D-glucose levels, yielding lower protein levels and somite numbers in embryos from diabetic serum culture than in embryos cultured in normal rat serum.(ABSTRACT TRUNCATED AT 400 WORDS)

A continuous 48-hour glucose infusion in rats causes both an acute and a persistent redistribution of the blood flow within the pancreas.

Male Sprague-Dawley rats were infused for 48 h at a rate of 1.8 ml/h with either a 30% solution of D-glucose or a 10% solution of D-mannitol. The blood perfusion of both the whole pancreas and the islets was measured with a microsphere technique either immediately after the infusion or 10 days later. Infusion of mannitol did not influence the serum glucose or the serum insulin concentration at any time point. Infusion of glucose, however, increased both the glucose and insulin concentrations during the infusion period, but 45 min after the infusion ended both the glucose and insulin concentrations had already returned toward the values found in the mannitol-infused rats. Intraperitoneal glucose tolerance tests were normal both immediately after the infusion and 8 days later. The glucose infusion caused a significant increase in whole pancreatic blood flow and islet blood flow when compared to mannitol-infused rats immediately after the infusion. The increase in blood perfusion of the islets was more marked than that to the whole pancreas since a larger fraction of the whole pancreatic blood flow was diverted through the islets. Ten days after the infusion there was still a marked increase in the fractional islet blood flow in the glucose-infused animals, whereas the absolute flow values for whole pancreatic or islet blood flow did not differ significantly between the groups. We conclude that continuous hyperglycemia for 48 h causes an acute increase in both whole pancreatic and islet blood flow, and that a redistribution of the blood flow within the gland is present 10 days after the infusion.

Diabetic embryopathy. Studies with animal and in vitro models.

Diabetic pregnancy is associated with an increased risk for fetal maldevelopment for a largely unknown reason. A decade ago, Norbert Freinkel suggested that the altered fuel mixture offered to the growing conceptus may be the key to most of the changes in the embryogenesis of diabetic pregnancy. He coined the term fuel-mediated teratogenesis. During early pregnancy, periods of maternal hyper- and hypoglycemia may cause marked changes in the availability of glucose to the conceptus. Also, increased concentrations of lipids, notably ketone bodies, and branched-chain amino acids in the maternal circulation contribute to a changed fuel mixture for the embryo. In a recent experimental study of diabetic rats, it was found that the maternal metabolism of all three major classes of nutrients and maternal somatic growth during gestation covaried with the development of the embryo. Consequently, the maintenance of normal concentrations of metabolites from all nutrient classes may be important for prevention of adverse fetal outcome in diabetic pregnancy. In vitro, a high glucose concentration causes embryonic dysmorphogenesis by generation of free oxygen radicals. An enhanced production of such radicals in embryonic tissues may be directly related to an increased risk of congenital malformations in diabetic pregnancy. Thus, the notion that alterations in the net transfer of cellular fuels from the diabetic mother to her offspring may cause embryonic dysmorphogenesis, which suggests that combustion of the fuel may produce compounds that impair embryonic development, has obtained experimental support. If this is also true for human diabetic pregnancy, it has therapeutic implications.

In vitro effects of glucose and growth factors on limb bud and mandibular arch chondrocytes maintained at various serum concentrations.

In human and experimental diabetic pregnancy there is an increased risk of congenital malformation in the offspring. Some malformations involve growth retardation and altered chondrocyte differentiation, suggesting that a diabetic milieu may modify embryonic cell replication and the development of (pre)chondrocytes. The aim of the present work was to study the effects of a diabetes-like environment in vitro on the growth and differentiation of rat chondrocytes in the presence of specific growth factors and different concentrations of serum. This was performed with a modified micromass culture system of embryonic (pre)chondrocytes from the limb bud and mandibular arch areas using medium supplemented with different glucose concentrations and with serum from diabetic rats. An elevated ambient glucose concentration inhibited the growth of mature chondrocytes in vitro, and this effect was diminished in a serum-rich culture milieu. The (pre)chondrocytes exhibited a marked dependence on the serum level in the culture medium for optimal in vitro development. Diabetic rat serum had the lowest stimulatory capacity of the three different types tested (at similar glucose concentrations), suggesting a deficiency of growth-stimulating factor(s) rather than the presence of inhibiting factor(s) in this type of serum. One of the deficient factor(s) in diabetic rat serum may be similar to IGF-II, but a combined deficiency of several growth-stimulating agents is likely to be present. Chondrocytes originating from the mandibular arch in general appeared more sensitive to MSA and IGF-II than those from the limb buds. The present observations support the notion that while diabetes-induced hyperglycemia in the conceptus contributes to severe growth retardation of the mandibular arch, additional factors also play a role.

Effects of D-glucose and beta-hydroxybutyric acid on the in vitro development of (pre)chondrocytes from embryos of normal and diabetic rats.

In order to elucidate cellular mechanisms causing skeletal malformations in offspring of diabetic rats we studied the incorporation of thymidine and sulphate into embryonic (pre)chondrocytes exposed to increased levels of D-glucose and beta-hydroxybutyric acid for six days in vitro. The (pre)chondrocytes were prepared from embryos of normal or diabetic rats of a malformation-prone strain or from embryos of normal rats of a non-malformation-prone strain. Diabetic female rats of the former strain are known to produce a high proportion of offspring with mandibular and lumbosacral malformations. Increased beta-hydroxybutyric acid caused decreased thymidine incorporation in all types of chondrocytes, and decreased sulphate incorporation in limb bud cells from embryos of normal rats from both strains. Elevated D-glucose levels yielded a slight decrease in thymidine incorporation in mandibular arch cells from embryos of normal rats of the malformation-prone strain, and a marked decrease of both sulphate and thymidine incorporation in mandibular arch cells from embryos of diabetic rats of this strain. The observations suggest that elevated levels of D-glucose or beta-hydroxybutyric acid are able to inhibit the differentiation and growth of (pre)-chondrocytes and illustrate a selective sensitivity of mandibular arch (pre)chondrocytes to a diabetic environment. The data are compatible with the view that both D-glucose and beta-hydroxybutyric acid may cause aberrations in the development of rat mandibular arch chondrocytes, suggesting a role for these compounds in diabetic teratogenesis.

Metabolism in vitro of cartilage proteoglycans in rat (pre)chondrocytes from different embryonic regions.

Diabetes in the mother may cause disturbances in the chondrocyte development in the embryo. A rat model was used to investigate whether this was reflected in the production of proteoglycans by cells from two embryonic regions. One of these regions is resistant (limb bud) and the other susceptible (mandibular arch) to malformation in diabetic pregnancy. Chondroitin sulphate proteoglycans from cultures of day-12 rat embryo limb bud and mandibular arch chondrocytes were extracted with guanidine-HCl and analyzed by gel chromatography after in vitro 35S-sulphate-labeling. Two sizes of proteoglycans (Kav 0.26 and 0.66 on CL-2B Sepharose) were found in both types of chondrocytes and in all media. The polysaccharide chain length was the same (Kav 0.36 on CL-6B Sepharose) for both proteoglycans. Elevated levels of D-glucose or beta-hydroxybutyric acid had no effect on either proteoglycan size or proportion, nor on polysaccharide chain length. However, there were differences (in all culture conditions) between limb bud and mandibular arch cultures in that the larger proteoglycan accounted for 80% of total radioactivity in the limb bud cultures, 53% in the mandibular arch cultures, and only 25-29% in the media from both types of cultures. Furthermore, different ratios between radioactive proteoglycans in medium and matrix suggested markedly different efficiencies for matrix formation in the two cell types. These findings indicate differences in the metabolism of the proteoglycans in these two cell types which may be related to the induction of mandibular malformation in diabetic pregnancy.

Mechanisms of congenital malformations in diabetic pregnancy.

The reasons for the increased rate of congenital malformations in diabetic pregnancy are unclear. Several different teratological agents may be considered. In clinical investigations and animal experimentation hyperglycemia and hypoglycemia, hyperketonemia, altered trace metal metabolism, and a genetic predisposition have been suggested to be of significance in the teratogenic process of diabetic pregnancy. Studies of these possible etiological factors have so far failed to reveal a single agent or mechanism as the most important. The diabetic pregnancy, therefore, appears to be of multifactorial origin.

Induction of skeletal malformations in the offspring of rats fed a zinc deficient diet.

Pregnant rats were subjected to a trace metal poor diet (1.2 ppm zinc, 5.9 ppm copper, 40 ppm manganese) during the entire gestation. The rat mothers did not gain weight during pregnancy and showed decreased liver weight and lowered serum glucose levels on gestational day 20. The offspring exhibited decreased body and placental weights, delayed ossification of the skeleton, and an increased resorption rate. We also found 4% skeletal malformations in the offspring (0% in the controls), which closely resembled a type of malformation previously encountered in rats when the mother was manifest diabetic (i.e. sacral dysgenesis). The zinc levels were decreased and manganese levels increased to the same extent in offspring of trace metal restricted (this study) and manifest diabetic rats (previous studies). Furthermore, when pregnant rats on the trace metal restricted diet were resupplemented with 75 ppm zinc in the drinking water the offspring largely normalized their somatic and placental growth, skeletal maturation, as well as their zinc and manganese levels. In addition, the fetuses of the zinc resupplemented rats did not show any malformations. The possibility of common teratological mechanisms in maternal diabetes and trace metal deficiency may therefore be considered.

Congenital malformations in diabetic pregnancy: the clinical relevance of experimental animal studies.

The aim of this work was to present recent observations on the occurrence of malformations in the offspring of diabetic rats and to discuss these findings in the light of present clinical experience. Comparison of malformation rates between different substrains of Sprague-Dawley rats showed marked differences in the occurrence of diabetes-induced malformations. These findings suggest that congenital malformations in diabetic pregnancy may result from a teratological insult in genetically predisposed individuals. Recent clinical reports seem to link facial malformations to an increased incidence of sacral-caudal malformations in human diabetic pregnancy. The present rat model, which expresses both these aberrations--micrognathia and sacral dysgenesis--may therefore be a useful tool in studies of the aetiological relationships between disturbed maternal metabolism and skeletal malformations in the offspring. Malformations in fetuses of diabetic animals seem to arise from teratogenic insult(s) early in pregnancy. Hyperglycemia and hyperketonemia may both singly, and in combination, be of teratological significance. Insulin itself does not appear to be directly teratogenic. Furthermore, there is evidence to suggest that disturbed levels of trace metals, primarily zinc, may be a significant factor in the production of congenital malformations. The increased rate of malformations in diabetic pregnancy, therefore, appears to be multifactorial in origin.