Serum Insulin-Like Growth Factor-1 (IGF-1) Age-Specific Reference Values for Healthy Adult Population of Serbia

CONTEXT

Insulin-like growth factor-1 (IGF-1) is main serum surrogate marker of growth hormone (GH) secretion, used in diagnostics and treatment of GH deficiency (GHD) and acromegaly. Regional, ethnic, racial or nutritional factors obscure cross-population applicability of IGF-1 reference values. Establishment of population- and assay-specific reference values requires sizable representative cohort of healthy subjects.

SUBJECTS AND METHODS

In representative sample of healthy adult population of Serbia (N=1200, 21-80 years, 1:1 male:female) serum IGF-1 was analyzed by Siemens Immulite 2000 assay under uniform laboratory conditions. Upper and lower limit of reference range (5^th - 95^th percentile) were calculated for each of the 12 quinquennial age intervals. IGF-1 distribution was normalized and standard deviation score (SDS) calculated by Logarithmic and LMS methods.

RESULTS

IGF-1 and age correlated significantly, with most prominent decline at 21-50 years, followed by a plateau up to age of 70. Gender differences were not significant overall. Plateau in age-related IGF-1 decline was less prominent in women. Correlations of IGF-1 with body mass index (BMI) or waist to hip ratio (WHR) were insignificant. Superior IGF-1 SDS transformation was achieved with LMS method, while logarithmic method was simpler to use.

CONCLUSIONS

Normative age-specific serum IGF-1 reference values were established on a representative cohort of healthy adults in Serbia. Our results support recommendations against necessity for gender-specific or BMI- and WHR-specific reference ranges. Population-based data serve to generate IGF-1 SDS, which is valuable in rational application of consensus guidelines, proper longitudinal follow-up, advancement in efficacy and safety and personalization of treatment targets.

FROM DIABETES INSIPIDUS TO SELLAR XANTHOGRANULOMA - A "YELLOW BRICK ROAD" DEMANDING TEAM-WORK

Xanthogranulomas are inflammatory lesions exceptionally rarely occurring in the sellar region. Sellar xanthogranulomas (SXG) result from secondary hemorrhage, infarction, inflammation or necrosis upon existing craniopharyngioma (CP), Rathkès cleft cyst (RCC) or pituitary adenoma (PA), or represent a stage in xanthomatous hypophysitis evolution. "Pure SXG" are independent of a preexisting lesion. A 70 year old male patient, laryngeal cancer survivor, presented with central diabetes insipidus (CDI). MRI revealed an intra-suprasellar mass of uncertain origin. Transsphenoidal surgery resulted in an efficient lesion resection with maximal pituitary sparing. Pathological report has confirmed SXG without conclusive identification of preexisting sellar lesion. Age at presentation and gender were atypical for SXG. The most frequent presenting signs of SXG were absent. Most SXG are initially misdiagnosed as CP, RCC or PA. Preoperative clinical and radiological uncertainty may impact operative planning. Differentiating from CP is crucial, due to divergent operative target goals and prognosis. Intraoperative frozen section analysis could guide surgical extensiveness. Close collaboration must include endocrinologist, neuroradiologist, neurosurgeon and pathologist. Quantity and quality of provided tissue are essential for avoiding bias in pathohistological analysis of cystic or heterogenous lesions. Awareness is needed of new pathological entities in the sellar-parasellar region. SXG should be considered in differential diagnosis of CDI-causing sellar lesions.

Etiology of Hypopituitarism in Adult Patients: The Experience of a Single Center Database in the Serbian Population

There are only a few published studies related to the population-based etiology of hypopituitarism. New risks for developing hypopituitarism have been recognized in the last 10 years. Aim. To present data regarding the etiology of hypopituitarism collected in a tertiary center over the last decade. This is a cross-sectional database study. Patients and Methods. We included 512 patients (pts) with hypopituitarism, with a mean age of 45.9 ± 1.7 yrs (range: 18-82; male: 57.9%). Results. Nonfunctional pituitary adenomas were presented in 205 pts (40.5%), congenital causes in 74 pts (14.6%), while acromegaly and prolactinomas were presented in 37 (7.2%) and 36 (7.0%) patients, respectively. Craniopharyngiomas were detected in 30 pts (5.9%), and head trauma due to trauma brain injury-TBI and subarachnoid hemorrhage-SAH in 27 pts (5.4%). Survivors of hemorrhagic fever with renal syndrome (HFRS) and those with previous cranial irradiation were presented in the same frequency (18 pts, 3.5% each). Conclusion. The most common causes of hypopituitarism in our database are pituitary adenomas. Increased awareness of the other causes of pituitary dysfunction, such as congenital, head trauma, extrapituitary cranial irradiation, and infections, is the reason for a higher frequency of these etiologies of hypopituitarism in the presented database.

Insulin resistance in non-obese women with polycystic ovary syndrome: relation to byproducts of oxidative stress

To get more insight into molecular mechanisms underlying oxidative stress and its link with insulin resistance, oxidative stress parameters, as well as, antioxidant enzyme activities were studied in young, non-obese women with polycystic ovary syndrome (PCOS). Study was performed in 34 PCOS women and 23 age and body mass index (BMI)-matched healthy controls. Plasma nitrotyrosine and malondialdehyde (MDA), representative byproducts of protein and lipid oxidative damage, were determined by enzyme immunoassay. Antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPX) were studied spectrophotometrically. Insulin resistance was calculated using homeostasis assessment model (HOMA-IR). Plasma nitrotyrosine and MDA were increased, but only nitrotyrosine was significantly higher (p < 0.05) in PCOS women compared to controls. Uric acid (surrogate marker of × antine oxidase) was also significantly elevated in PCOS (p < 0.05). Both plasma SOD and GPX activity showed no statistically significant difference between PCOS and controls. Indices of insulin resistance (insulin and HOMAIR) were significantly higher in PCOS group and positively correlated with level of MDA (r = 0.397 and r = 0.523, respectively; p < 0.05) as well as GPX activity (r = 0.531 and r = 0.358, respectively; p < 0.05). Our results indicate that insulin resistance could be responsible for the existence of subtle form of oxidative stress in young, nonobese PCOS women. Hence, presence of insulin resistance, hyperinsulinemia and oxidative damage are likely to accelerate slow development of cardiovascular disease in PCOS.

Collection strategies and cryopreservation of umbilical cord blood

The aim of this study was to compare (a) two different umbilical cord blood (UCB) collection methods while the placenta is still in the uterus (in utero), and (b) to evaluate the efficacy of four cryopreservation protocols based on UCB haematopoiestic stem cell (HSC) recovery. We analysed UCB samples collected with our original collection system designed for active Syringe/Flush/Syringe method or by standard in utero method. For comparing different cryopreservation procedures, dimethyl sulphoxide (DMSO) at final concentration of 5 and 10% was used and combined with our own controlled-rate or uncontrolled-rate cryopreservation. A total of 99 samples were collected. A significantly higher UCB volume, total nucleated cell and mononuclear cell were seen following the first collection strategy (n= 49; mean +/- SD, 103 +/- 35.4 mL; 12.34 +/- 5.27 x 10(8); 595 +/- 3.47 x 10(6)) vs. the second strategy (n= 50; 86 +/- 29.3 mL; 9.87 +/- 4.47; 424 +/- 2.82 x 10(6)) respectively (P < 0.01). The discard rate was 14% for the first and 36% for the second collection strategy (P < 0.01). It was shown that the most efficient procedure was the controlled-rate protocol combined with lower (5%) DMSO concentration. Using active Syringe/Flush/Syringe method, we collected UCB with greater volumes and with lower discard rate compared to the standard by gravity technique. The data presented also showed much better recovery of UCB cells when controlled-rate freezing procedure and 5% DMSO were combined.

The effect of interleukin-17 on hematopoietic cells and cytokine release in mouse spleen

To evaluate whether the response of hematopoietic cells to interleukin-17 (IL-17) depends on the tissue microenvironment in which hematopoiesis occurs, the influence of recombinant mouse IL-17 on spleen hematopoietic cells and cytokine release was assessed in normal mice in vitro and in vivo. In vitro, IL-17 did not significantly affect the growth of granulocyte-macrophage (CFU-GM) and erythroid (BFU-E and CFU-E) derived colonies. A single injection of IL-17 in vivo exhibited stimulatory effects on hematopoietic cells from both granulocytic and erythroid lineages. The increased number of metamyelocytes 48 h after treatment imply to the IL-17-induced stimulation of granulopoiesis. The number of BFU-E was increased at 24 h, while the number of CFU-E increased 6 h and 24 h after treatment. Since the same treatment in the bone marrow decreased the number of CFU-E, it may be concluded that the local microenvironment plays an important role in IL-17-mediated effects on CFU-E. IL-17 increased the release of IL-6 both in vitro and in vivo, but showed tendency to suppress the constitutive secretion of IL-10 by spleen cells. Our results suggest the complexity of target cell response and interplay of secondary induced cytokines by IL-17 in different hematopoietic organs.

[Endoscopic ultrasonography (EUS) in preoperative localization of neuroendocrine tumors (NET) of the pancreas]

BACKGROUND

Preoperative localization of pancreatic neuroendocrine tumours (NET) is usually very difficult. Noninvasive, imaging tests, such as abdominal ultrasound, CT or MRI are not sensitive enough as well as selective angiography. The aim of the study was to clarify the usefulness of the EUS in preoperative localization of the pancreatic NET.

METHODS

From September 1998 March 2005, EUS was performed in 1600 patients. Among them, in 10 (0.7%), this examination was carried out due to previous biochemical tests, which diagnosed the pancreatic NET. We studied the location, the size and echo-pattern of the neoplasm. The results were compared with operation and histology or EUS- FNA guided pancreatic biopsy in 9/10 patients. All EUS examinations were performed using Olympus GIF-130 videoecho-endoscope with 7,5 /12MHz switchable radial probe.

RESULTS

EUS correctly localized the pancreatic NET in 7/8 cases, (sensitivity:87.5%). In 2 patients, EUS accurately exclouded pancreatic NET. There were no false positive findings (specificity 100%). Six tumours were benign (75%), and two were malign (25%). We localized 6 insulinomas and single pancreatic carcinoid tumour. The median tumour size detected by EUS was 21mm.

CONCLUSION

EUS is highly accurate in preoperative localization of the pancreatic NET-s and We confirmed it in our study. EUS presents the method of choice for preoperative localization of the pancreatic NET.

In vivo effects of interleukin-17 on haematopoietic cells and cytokine release in normal mice

In order to gain more insight into mechanisms operating on the haematopoietic activity of the T-cell-derived cytokine, interleukin-17 (IL-17) and target cells that first respond to its action in vivo, the influence of a single intravenous injection of recombinant mouse IL-17 on bone marrow progenitors, further morphologically recognizable cells and peripheral blood cells was assessed in normal mice up to 72 h after treatment. Simultaneously, the release of IL-6, IL-10, IGF-I, IFN-gamma and NO by bone marrow cells was determined. Results showed that, in bone marrow, IL-17 did not affect granulocyte-macrophage (CFU-GM) progenitors, but induced a persistant increase in the number of morphologically recognizable proliferative granulocytes (PG) up to 48 h after treatment. The number of immature erythroid (BFU-E) progenitors was increased at 48 h, while the number of mature erythroid (CFU-E) progenitors was decreased up to 48 h. In peripheral blood, white blood cells were increased 6 h after treatment, mainly because of the increase in the number of lymphocytes. IL-17 also increased IL-6 release and NO production 6 h after administration. Additional in vitro assessment on bone marrow highly enriched Lin- progenitor cells, demonstrated a slightly enhancing effect of IL-17 on CFU-GM and no influence on BFU-E, suggesting the importance of bone marrow accessory cells and secondary induced cytokines for IL-17 mediated effects on progenitor cells. Taken together, these results demonstrate that in vivo IL-17 affects both granulocytic and erythroid lineages, with more mature haematopoietic progenitors responding first to its action. The opposite effects exerted on PG and CFU-E found at the same time indicate that IL-17, as a component of a regulatory network, is able to intervene in mechanisms that shift haematopoiesis from the erythroid to the granulocytic lineage.

Gonadotropin response to clomiphene and plasma leptin levels in weight recovered but amenorrhoeic patients with anorexia nervosa

Anorexia nervosa (AN) is a state of leptin and gonadotropin deficiency. Leptin levels are decreased in normal weight women with hypothalamic amenorrhea and leptin may be a sensitive marker of overall nutritional status. The aim of the study is to provide additional information on plasma leptin levels and on gonadotropin responses after clomiphene testing in patients with AN who recovered weight but were still amenorrheic. We evaluated 17 patients with AN, female age 20+/-1.2 yr who reached goal weight [body mass index (BMI) 14.9+/-0.5 to 19.3+/-0.4 kg/m2]. At diagnosis serum leptin levels were 2.2+/-0.1 microg/l while after behavioural therapy and hypercaloric diet for 6-12 months serum leptin levels rose to 6.4+/-1.4 microg/l significantly lower compared with those in the control (no.=10, age 28+/-6.2 yr, BMI 21.1+/-0.3 kg/m2, leptin 9.3+/-0.7 pg/l; p<0.05). None of the patients resumed spontaneous menstrual cycles after weight gain. They were tested with a 10-day administration of clomiphene citrate. All had a significant rise in LH secretion (from 1.7+/-0.3 IU/l to 8.3+/-0.9 IU/l, p<0.01) and serum estradiol levels (from 19.0+/-5.4 to 937.7+/-241.2 pg/ml, p<0.03). Nine out of 17 patients menstruated after clomiphene. Serum leptin levels were not different in those who menstruated from those who did not (6.4+/-1.4 to 6.8+/-1.4 microg/l, p>0.05). Body compositon was studied in 12 additional carefully matched patients with AN who recovered weight. Six of them resumed spontaneous menstrual cycles. Neither BMI, body fat, nor leptin appeared as significant determinants of menstrual status. In conclusion, relative hypoleptinemia persists, independent of fat mass, in weight recovered patients with AN. A normal response to clomiphene in weight-recovered yet still amenorrhoeic patients with AN, offers reassurance that the axis is intact and that the problem lies in the hypothalamus. It is reasonable to believe that nutritional disturbances, fat intake and persisting psychological factors still affect plasma leptin levels and reproductive functions in weight-recovered patients with amenorrhea.

Hematopoiesis during acute Toxoplasma gondii infection in mice

We studied hematopoiesis in bone marrow and blood of CBA mice following infection with Toxoplasma gondii. Our data showed that acute infection with the virulent RH strain was associated with leucopenia, thrombocytopenia and bone marrow hypoplasia while, in spite of the infection-induced damage of the granulocyte cell lineage, in bone marrow stimulated production of granulocytes was revealed. In peripheral blood, T. gondii infection caused a significant decrease in the total number of white blood cells, reticulocytes and platelets. However, the relative proportion of granulocytes and lymphocytes was changed in favor of granulocytes, as compared to pre-infection levels. The functional activity of granulocytes was also increased. The bone marrow alterations were characterized by a decrease in the total number of nucleated cells due to the reduced numbers in all cell compartments of erythroid and megakaryocytic lineage, as well as in the number of mature granulocytes and lymphocytes. In contrast, femoral granulocytic proliferative compartments, colony forming unite granulocyte-macrophage (CFU-GM) and morphologically recognizable proliferative granulocytes (PG), exhibited stimulated granulopoiesis, while the number of mature monocytes was close to the control value. In summary, we have shown that acute T. gondii infection results in profound alterations of the hematopoietic system that markedly contribute to the clinical onset of the disease and the, ultimately lethal, outcome.

Case report of hypopituitarism with suspected syndrome of inappropriate VP secretion (SIADH) due to a large aneurysm of the internal carotid in the sellar region

Hypopituitarism and hyponatremia, especially when severe, are infrequent findings particularly when the cause of hypopituitarism at presentation is unknown and untreated. Interestingly, hyponatremia is usually seen in elderly patients with hypopituitarism due to various causes. We present a case with unrecognized and untreated hypopituitarism due to a large aneurysm of the internal carotid artery in the sellar region causing the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Loss of gender difference in serum leptin levels and its slow recovery after successful surgery for Leydig cell tumours in two virilized females

One of the factors that predicts serum leptin levels is gender. It has been shown that sex steroid hormones, in particular testosterone, play an important role in the regulation of serum leptin levels. We had the opportunity to examine the effects of acute and chronic changes in serum testosterone levels on serum leptin concentrations in two virilized females harbouring testosterone-secreting ovarian tumours, before and after curative surgery. Chronically elevated basal testosterone levels (46 nmol/l) were associated with suppressed serum leptin levels (1.46 microg/l and 2.56 microg/l) vs. 12 age- and BMI-matched healthy subjects 9.89 +/- 0.64 microg/l. Leptin levels were determined from pooled serum samples assayed by commercial radioimmunoassay. High testosterone levels abolished the well known sexual dimorphism of serum leptin levels. Two weeks after curative resection of these tumours serum leptin levels were unaltered and started to increase progressively after one month. One patient received parenteral conjugated oestrogens while the other resumed spontaneous menstrual cycles. Three months after curative surgery obvious changes in body composition were registered (DEXA). Six months later further rise in serum leptin concentrations occurred without further changes in body composition. In conclusion, leptin levels did not change in spite of rapid changes in the steroid milieu, but in the long term increase in body fat stores, new steroid milieu and maybe other factors are important determining factors of serum leptin levels.

Effects of treatment with interleukin-1 receptor antagonist on endogenous interleukin-1 levels in normal and irradiated mice

The in vivo effects of recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) administration on endogenous IL-1 levels in the circulation and conditioned media (CM) from different immunohematopoietic organ/tissues were studied in CBA mice under steady state and postirradiation conditions. In normal mice, constitutive IL-1 levels were demonstrated in the plasma, CM of peritoneal exudate cells and full-thickness skin explants with low or undetectable levels in CM of splenic and bone marrow cell suspensions. In irradiated mice (2 Gy, X rays) on day 3 post exposure a significant increase of IL-1 levels was seen in the circulation and CM of peritoneal exudate cells, with no significantly different levels in postirradiation bone marrow, spleen and skin. After rhIL-1Ra treatment of the animals (2 x 50 microg/mouse, i.p.), significantly elevated IL-1 levels were observed in the skin and CM of peritoneal exudate cells in normal mice, whereas slightly increased levels were detected in CM of splenic cells. The rhIL-1Ra administration in irradiated mice led to decreased IL-1 concentrations in the circulation, and CM of peritoneal exudate cells and skin. The results pointed out the importance of IL-1 secretion and receptor expression in the maintenance of homeostasis in steady state, as well as during recovery after irradiation. Modulatory effects of IL-1Ra on IL-1 production were dependent on basic endogenous IL-1 concentration.

Effect of IL-17 on in vitro hematopoietic progenitor cells growth and cytokine release in normal and post-irradiated murine bone marrow

The influence of recombinant human IL-17 on granulocyte-macrophage (CFU-GM) and erythroid (BFU-E and CFU-E) progenitors and the release of IL-1alpha/beta, IL-6 and erythropoietin (EPO) was estimated in the bone marrow cells obtained from normal and sublethally irradiated mice. In normal mice IL-17 increased CFU-GM and BFU-E and reduced CFU-E derived colonies numbers and augmented release of IL-6 and EPO. In irradiated mice the effects of IL-17 on hematopoietic progenitors were lineage-dependent, as well as dependent on their stage of differentiation and the time after the irradiation. IL-17 had no major effects on CFU-GM on day 1 and 3, but decreased their number on day 2, while enhanced both BFU-E and CFU-E on day 1 and 2 after irradiation, whereas on day 3 its effect on erythroid progenitors was again as observed in normal mice. After irradiation, IL-17 increased the release of IL-1alpha, IL-6 and EPO. The observed effects suggested the involvement of IL-17 in the regulation of hematopoiesis and indicated that its effects on both hematopoietic progenitors and cytokine release are dependent on the physiological/pathological status of the organism.

Donor leukocyte infusion--the effect of mutual reactivity of donor's and recipient's peripheral blood mononuclear cells on hematopoietic progenitor cells growth

Donor leukocyte infusions are an effective therapy for patients who relapse with leukemia after bone marrow transplantation. We report the case of 14-year-old boy who relapsed 34 months after sibling donor bone marrow transplant for Philadelphia-positive chronic myeloid leukemia. Subsequently, he received three infusions of donor mononuclear cells (DMNC) harvested in steady state hematopoiesis and one G-CSF mobilized-peripheral blood mononuclear cells (PBMC) infusion. Simultaneously, test named as--"Test of Mixed Progenitors" (TMP) was performed for the assessment whether the outcome of donor leukocyte infusion treatment could be predicted. Prior to DMNC infusions, the CFU-GM and BFU-E colony assays were performed for donor's and recipient's PBMC individually, as well as for the mixture of these cells at 1:1 ratio. The cells were plated either directly in the semisolid medium or after 24 h preincubation treatment. Significantly lower values for CFU-GM derived colonies were determined in TMP in comparison to the CFU-GM values obtained for the recipient's cells. The reduced number of CFU-GM was determined both in TMP performed without preincubation treatment, app. 80% and after the 24 h preincubation, app. 55%. The reduced number of BFU-E derived colonies (app. 44%) was observed only related to recipient's cells and after the preincubation treatment of the cells. The patient did not develop GVHD and currently (40 months after the first infusion). He remained well in complete hematological, cytogenetic, molecular and clinical remission, which was the most direct evidence of the GVL effect. The novel in vitro TMP test in which the specific contribution of donor's leukocytes to the growth of recipient's hematopoietic precursor cell growth was determined, correlated with the clinical outcome.

Evaluation of cryopreserved murine and human hematopoietic stem and progenitor cells designated for transplantation

The influence of five different cryopreservation protocols on the quality and/or quantity of frozen cells was investigated on mouse bone marrow cells and human peripheral blood mononuclear cells (MNC). The efficiency of the protocols was evaluated on the basis of the recovery of very primitive pluripotent hematopoietic stem cells (MRA), pluripotent progenitors (CFU-Sd12), committed granulocyte-monocyte progenitors (CFU-GM) of mouse cells after thawing. The recovery of MRA, CFU-Sd12 and CFU-GM varied depending on the type of freezing procedure and cryoprotector (DMSO) concentrations used. It was shown that the controlled-rate protocol was more efficient, enabling better recovery of all categories of progenitor cells in frozen samples. The most efficient was the controlled-rate protocol of the cryopreservation designed to compensate for the release of fusion heat, which enabled the best recovery of CFU-GM (73.0 +/- 8.8%) and CFU-Sd12 (90.0 +/- 15.9%) when combined with 5% DMSO concentration (protocol 4). On the contrary, a better recovery (79.8 +/- 13.5%) of very primitive stem cells (MRA) was achieved only when the higher concentration (10%) DMSO was used in combination with a five-step protocol of cryopreservation (protocol 1). These results pointed out the adequately used controlled-rate freezing to be essential for a highly efficient cryopreservation of some of the categories of hematopoietic stem and progenitor cells. At the same time, it was obvious that a higher DMSO concentration was necessary for the cryopreservation of MRA, but not for more mature progenitor cells (CFU-S, CFU-GM). These results imply the existence of a mechanism that decreases the intracellular concentration of DMSO in MRA cells, which is not the case in less primitive progenitors. For human MNC, the recovery and viability of the cells, as well as the engraftment potential of cryopreserved cells after thawing were investigated. Cryopreservation protocol 1 resulted in better MNC recovery (82.7 +/- 10.4%) than protocol 3 (49.9 +/- 15.1%). The mean recovery of MNCs (collected from patients for autologous transplantation) was 78.5 +/- 7.3% (protocol 1) and 53.1 +/- 26.2% (protocol 3). The obtained favorable recovery of thawed cells and rapid reconstitution of hematopoiesis (on the day 11th following the transplantation) in patients confirmed that the controlled-rate freezing in combination with optimal DMSO concentration was able to obtain sufficient progenitor cryoprotection.

The in vivo effect of liposomes on hematopoiesis

The influence of liposome structure on hematopoiesis in vivo was assessed in relation to the different contents and origins of phospholipids that make up their membrane structures. Changes within different hematopoietic cells and serum tumor necrosis factor alpha (TNF-alpha) levels were estimated up to 14 days following intravenous administration of liposomes made of either pure egg yolk phosphatidylcholine (LEY) or a soybean phospholipid preparation (LSB) into normal CBA mice. In peripheral blood, only transient changes within white blood cells were observed. In bone marrow, a persistent decline in the number of mature granulocytes, monocytes, and lymphocytes was found. The changes within femoral granulocytic proliferative compartments in various stages of differentiation and a maturation compartment pointed out that, parallel with the depletion of the granulocyte-storage pool, stimulation of de novo production of granulocytic cells occurred. Although both types of tested liposomes induced similar cellular changes, only liposomes made of pure egg yolk phosphatidylcholine induced a transient increase in serum TNF-alpha levels.

Cytochemical & ultrastructural alteration of cytoplasmic granules of rat peripheral blood neutrophils induced by chronic alcoholism & malnutrition

The specific influence of malnutrition on the pathophysiologic changes induced by chronic alcoholism is controversial. In an attempt to determine and demarcate the effects of protein malnutrition from those produced by alcoholism and to evaluate the precise effect of alcohol per se on cytochemical and ultrastructural properties of rat polymorphonuclear neutrophil (PMN) granules, we investigated the influence of chronic protein malnutrition or chronic alcoholism alone and in combination, in rats. After a 4 month experimental period various PMN properties, such as cytochemical, morphometrical and ultrastructural, as well as neutrophil functions were studied. It was found that the degree of damage of PMNs induced either by ethanol or protein malnutrition alone was similar whereas their combination led to worsening of all markers of PMN functional ability. Ultrastructural changes of neutrophil granules including reduction, redistribution and atypical accumulation as well as appearance of autophagic vacuoles, confirmed their alteration which was emphasised by the additive pathophysiological interaction of alcoholism and chronic hypoprotein malnutrition.

The cryopreservation protocol optimal for progenitor recovery is not optimal for preservation of marrow repopulating ability

The efficiency of five different cryopreservation protocols (our original controlled-rate and noncontrolled-rate protocols) was evaluated on the basis of the recovery after thawing of very primitive pluripotent hemopoietic stem cells (MRA(CFU-GM), pluripotent progenitors (CFU-Sd12) and committed granulocyte-monocyte progenitors (CFU-GM) in mouse bone marrow. Although the nucleated cell recovery and viability determined immediately after the thawing and washing of the cells were found to be similar, whether controlled-rate or noncontrolled-rate cryopreservation protocols were used, the recovery of MRA(CFU-GM), CFU-Sd12 and CFU-GM varied depending on the type of protocol and the cryoprotector (DMSO) concentrations used. It was shown that the controlled-rate protocol was more efficient, enabling better MRA(CFU-GM), CFU-Sd12 and CFU-GM recovery from frozen samples. The most efficient was the controlled-rate protocol of cryopreservation designed to compensate for the release of fusion heat, which enabled a better survival of CFU-Sd12 and CFU-GM when combined with a lower (5%) DMSO concentration. On the contrary, a satisfactory survival rate of very primitive stem cells (MRA(CFU-GM)) was achieved only when 10% DMSO was included with a five-step protocol of cryopreservation. These results point to adequately used controlled-rate freezing as essential for a highly efficient cryopreservation of some of the categories of hematopoietic stem and progenitor cells. At the same time, it was obvious that a higher DMSO concentration was necessary for the cryopreservation of very primitive stem cells, but not, however, for more mature progenitor cells (CFU-S, CFU-GM). These results imply the existence of a mechanism that decreases the intracellular concentration of DMSO in primitive MRA cells, which is not the case for less primitive progenitors.

Increased incidence of neoplasia in patients with pituitary adenomas. The Pituitary Study Group

OBJECTIVE

The goal of our study was to determine the rate of neoplasms in patients with other pituitary adenomas (non-functioning and prolactinomas) in comparison with acromegaly which is known to favour the development of neoplasia.

DESIGN AND PATIENTS

We reviewed clinical records for 220 patients with acromegaly, 151 patients with non-functioning pituitary adenoma (NF) and 98 patients with prolactinomas. Incidence rates of cancer for patients with pituitary tumours were calculated per person-years of follow-up study. These rates were then compared with sex and age adjusted incidence rates reported by National Tumour Registry. An internal control group of 163 subjects with a non-neoplastic condition, i.e. Graves' disease followed chronically in the same clinic was also studied. The ratios observed to expected were expressed as standardized incidence rates (SIR). The only significant difference between the acromegalic and other pituitary tumours patients was in hypopituitarism, present in 18.2% (acromegaly) 47% (NF) and 18.6% (prolactinomas).

RESULTS

Twenty-three malignant tumours were registered in 19 acromegalics (1 Hodgkin disease, 1 myelogenous leukaemia, 1 lymphocytic leukaemia, 3 papillary thyroid carcinomas, 1 ovarian carcinoma, 2 colorectal carcinoma, 1 renal cell carcinoma, 4 cervical carcinoma, 2 skin cancers, 2 pancreatic carcinoma, 4 breast carcinoma, 1 bladder carcinoma). Three acromegalics harboured two malignancies. Patients with acromegaly had a 3.39-fold increased rate of malignant tumours compared with the general population and a 3.21-fold increased rate compared with our internal control group. Eleven malignant tumours were found in patients with NF-pituitary adenomas and 2 in prolactinoma patients (1 lymphoma, 1 multiple myeloma, 1 colonic cancer, 1 renal cell cancer, 1 stomach cancer, 2 lung cancers, 1 cervix carcinoma, 1 breast cancer, 1 testicular carcinoma and 3 melanoma). Patients with NF pituitary adenomas had a 3.91-fold increased rate of malignant tumours compared with the general population and 4.07-fold increase compared with the internal control group. Patients harbouring prolactinomas did not have an increased incidence rate of malignancy compared with the general population or our internal controls. Female patients with acromegaly and male patients with NF-pituitary adenoma had higher incidences of neoplasia.

CONCLUSION

We have demonstrated that the overall incidence of malignant tumours in patients with non-functioning pituitary adenomas and acromegaly is significantly higher than expected for general population and for our internal control group.

The influence of acute sterile inflammation on erythropoiesis in rats

Many different cell types, coordinated by proinflammatory mediators, take part in the acute inflammatory reaction, but there is a lack of evidence regarding the role of erythroid cells in such conditions. In this study, changes in bone marrow, splenic, and peripheral blood erythroid cells and in erythropoietin (Epo) blood levels were investigated up to 72 hours after polyvinylpyrrolidone (PVP)-induced sterile inflammation in male Wistar rats (two intraperitoneal injections of 15 mL 3.5% PVP at 18-hour intervals). Transient changes within progenitor erythroid cells were observed in the bone marrow. Significant increases in the number of splenic immature erythroid progenitors (BFU-E) 6 hours and mature erythroid progenitors (CFU-E), erythroblasts, and orthochromatic erythroblasts 48 and 72 hours after the induction of inflammation pointed to stimulated splenic erythropoiesis. This was confirmed by semiquantitative assessment of splenic smears, which demonstrated expansion of erythroid cells at hours 48 and 72. The changes observed in the bone marrow and spleen indicated that during acute inflammation erythropoiesis was stimulated and that the spleens of PVP-treated rats were favorable to erythroid development. The significant increase in the percentage of peripheral blood reticulocytes 48 and 72 hours after PVP-induced inflammation provided evidence that effective erythropoiesis occurred. In spite of the stimulated erythropoiesis, serum levels of Epo remained unchanged, implying that other non-Epo regulatory molecules may be responsible for erythroid cellular changes.

Serum leptin and insulin concentrations in patients with insulinoma before and after surgery

Inferential studies suggest that circulating insulin concentrations positively regulate leptin secretion by adipocytes. In humans, however, insulin requires prolonged periods of time, and relatively artificial set-ups before a relationship with leptin can be observed. In the present work, serum leptin concentrations were measured in five patients with insulinoma before and one month after surgery and in five control subjects matched by sex and body mass index (BMI). The control subjects presented a mean serum leptin concentration of 6.7+/-1.5 microg/l and a BMI of 24.9+/-1.1. The mean serum leptin concentration in patients with insulinoma was 11.8+/-3.1 microg/l (P < 0.05 vs controls), with a BMI of 26.3+/-1.9. After surgery, there was a non-significant reduction in BMI (25.8+/-1.7), and a clear reduction in serum leptin concentration (5.6+/-2.4 microg/l, P < 0.05 vs pre surgical values and no difference vs control subjects). The fasting area under the curve (AUC) of insulin concentration (in mU/l per 120 min) before surgery was 14421+/-4981 and after surgery was 1306-/+171 (P < 0.05). Before surgery, serum leptin concentrations significantly correlated with BMI (r = 0.71) and AUC of insulin (r = 0.82), a correlation that was lost after surgery. In conclusion, serum leptin concentrations are significantly elevated in patients with chronically high insulin levels due to insulinoma. After surgical treatment and normalization of insulin values, leptin levels return to normal.

Growth hormone secretagogues in pathological states: diagnostic implications

The identification and cloning of the receptor for synthetic growth hormone (GH) secretagogues, even before the endogenous ligand has been identified or its precise physiological role established, suggests that there is a novel target of action for this class of drug. In an attempt to select patients who will benefit from GH treatment, GH secretagogues are being evaluated for their usefulness in diagnosing GH deficiency. The effects of GH-releasing peptides (GHRPs) on GH release as a function of age and metabolic status, and in different neuroendocrine pathologies, are described, as are the different mechanisms of action, potency and reproducibility of the response to GHRPs compared with GH-releasing hormone (GHRH). GHRPs offer the advantage over GHRH in natural models of deranged GH secretion in that, in various metabolic states (e.g. obesity, anorexia nervosa and non-insulin-dependent diabetes mellitus), the GH response to GHRH is more impaired than it is to GHRPs. However, in some neuroendocrine pathologies, the reverse is true. Thus, both secretagogues provide separate information on the physiological status of somatotrophs.

Pituitary enlargement due to primary hypothyroidism: growth hormone response to GHRH, GHRP-6 and GHRH plus GHRP-6

GH secretion after growth hormone-releasing hormone (GHRH), growth hormone releasing peptide-6 (GHRP-6) and after combined administration of both peptides was studied in a patient with lactotrope and thyrotrope hyperplasia due to primary hypothyroidism. Pituitary pseudotumor disappeared after thyroid hormone replacement; this was evidenced by magnetic resonance imaging (NMR). There was no difference between areas under the curve (AUCzero-120 min) during GHRH test before and after thyroid hormone replacement (136.5 vs 129.0 micrograms/l min). Maximal GH increases over basal values (delta GH) did not change (1.5 and 1.9 micrograms/l). GH secretion induced by GHRP-6 increased after treatment (AUCzero-120 min 197.2 vs 650.4 micrograms/l min). delta GH increments were 4.0 and 18.3 micrograms/l before and after therapy respectively. When the peptides were administered together a synergistic effect on GH secretion was observed but GH release was much more powerful after pituitary pseudotumor disappearance (AUCzero-120 min 1043.2 vs 2046.7 micrograms/l min). This was accompanied by increased delta GH (22.7 vs 35.5 micrograms/l). The synergic action of peptides normalized in euthyroid condition and after the resolution of pituitary pseudotumor mainly due to improved GH response to GHRP-6. Blunted response of GH to GHRP-6 and GHRP-6 plus GHRH were in part due to known effects of hypothyroidism on GH secretion. Hypothalamopituitary disconnection and/or decrease in the synthesis of an unknown factor in the hypothalamus which mediates the effects of GHRP-6 may have participated in the GH responsiveness of this patient. This case adds to in vivo evidence that GHRP-6 operates through a non-GHRH dependent mechanism.

Growth hormone (GH) secretion in active acromegaly after the combined administration of GH-releasing hormone and GH-releasing peptide-6

His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (called GHRP-6) is a synthetic compound that releases GH in a dose-related, specific, and nonspecies-specific manner, through mechanisms different from those of GHRH. Being, normally, more potent than GHRH, GHRP-6 shows a striking synergistic action when administered simultaneously with GHRH, although the mechanisms and point of action of such a potentiating effect are unknown. The aim of the present study was 2-fold: 1) to further characterize the actions and mechanisms of GHRP-6 as well as its synergistic effects, and 2) to study its actions in acromegalic patients. Eleven acromegalic patients and 12 normal subjects, age and sex matched as controls, underwent 3 tests each on separate occasions, being challenged with GHRH (100 micrograms, iv), GHRP-6 (90 micrograms, iv), or GHRH plus GHRP-6. GH was analyzed as the area under the curve (mean +/- SE; micrograms per L/120 min). In normal subjects, GH secretion was 686 +/- 227 after GHRH, 1787 +/- 510 after GHRP-6, and 4111 +/- 671 after GHRH plus GHRP-6; the level of GH secreted after GHRH plus GHRP-6 treatment was significantly (P < 0.05) higher than the arithmetic sum of GH levels after both compounds administered separately. In acromegalic patients, the level of GH secreted after GHRH was 1468 +/- 499, that after GHRP-6 was 2595 +/- 762, and that after GHRH plus GHRP-6 was 4949 +/- 1043; this last value was not significantly different from the arithmetical addition of levels produced by both compounds administered separately. These results indicate that GH-secreting pituitary adenomas respond surprisingly well to either GHRH or GHRP-6 despite being deprived for long periods (even years) of the physiological regulation exerted by the hypothalamus. In addition, the synergistic action of GHRH plus GHRP-6 was observed in normal subjects, but not in acromegalic patients. These results suggest that GHRP-6 does not need to operate through hypothalamic factors to exert its GH-releasing action, even for eliciting a greater response than GHRH. On the other hand, the synergistic effect of GHRH plus GHRP-6 appears to need the cooperation of the hypothalamus, but how this occurs is still undetermined.

Acute sterile inflammation--correlation between cellular changes and extramedullary-produced regulators in vivo

Rats with polyvinylpyrrolidone (PVP)-induced sterile inflammation were used as a model in vivo for investigation of granulopoiesis and extramedullary-produced regulators. The data obtained demonstrated the invasion of massive numbers of granulocytes at the site of inflammation (peritoneal cavity) during the first 24 h of the acute phase of inflammation. To meet the organism's needs for granulocytes the activation of granulopoiesis in bone marrow occurred simultaneously. Accelerated production of granulocytic cells is manifested by involvement of granulocytic proliferative compartment in various stages of differentiation (CFU-GM and morphologically recognizable proliferative granulocytes--PG). Together with cellular changes within the granulocytic cells line, the changes in the content of investigated regulators influencing granulopoiesis were observed. At different time intervals the levels of interleukin-6 (IL-6), colony-stimulating activity (CSA), and granulocytic stimulating activity (GSA) were increased locally at the site of inflammation as well as in serum. The data obtained provide evidence that inducible granulopoiesis during the acute phase of inflammation is under the control of extramedullary-produced regulators, thus confirming their role in the regulation of granulocytic production in vivo.

Further evidence for differential regulation of follicle-stimulating hormone (FSH) and luteinizing hormone (LH): increased FSH and decreased LH levels in a patient with familial pure gonadal dysgenesis

There is experimental evidence that a portion of follicle-stimulating hormone (FSH) secretion is independent of hypothalamic influences. A 29 year old woman with familial pure gonadal dysgenesis developed myelodysplastic syndrome. Endocrine investigations showed discrepancy between serum FSH and luteinizing hormone (LH) levels. FSH levels remained elevated while LH levels decreased. The FSH to LH ratio was 10 (normal 2-2.5). The fall in LH is likely to be due to factor(s) involved directly and specifically in LH synthesis and release. Exogenous LH releasing hormone administration as well as hormonal replacement treatment increased LH levels. The FSH to LH ratio decreased to 7. This case supports the hypothesis of differential regulation of FSH and LH, and that FSH secretion is at least partly autonomous.

GH response to growth hormone releasing hormone and hypoglycaemia is unaltered by high endogenous plasma calcitonin levels in patients with medullary thyroid carcinoma

OBJECTIVE

As it has previously been reported that calcitonin suppresses stimulated growth hormone release, we have studied the serum growth hormone response to growth hormone releasing hormone and insulin-induced hypoglycaemia in patients with high calcitonin levels due to medullary carcinoma of the thyroid.

DESIGN

Growth hormone releasing hormone (100 micrograms i.v.) and insulin (0.15 units/kg i.v.) were given and the growth hormone responses in the patients with medullary carcinoma of the thyroid and normal healthy controls were compared.

PATIENTS

Eight with histologically confirmed medullary thyroid carcinoma, two females and six males, aged 21-77 years, were studied and compared with seven healthy age and sex matched controls.

MEASUREMENTS

Growth hormone and calcitonin were measured.

RESULTS

No significant difference was found between the growth hormone responses observed in patients with medullary carcinoma when compared with normal controls either after GHRH or during insulin-induced hypoglycaemia.

CONCLUSION

We conclude that calcitonin does not alter the pituitary response to GHRH in medullary thyroid carcinoma and is unlikely to play an important role in regulating growth hormone secretion because calcitonin did not modify the release of growth hormone after insulin-induced hypoglycaemia.

Follicle stimulating hormone-secreting pituitary adenoma: inappropriate secretion and effect of pulsatile luteinizing hormone releasing hormone analogue (buserelin) administration

A patient with an FSH secreting pituitary adenoma is reported. Elevated FSH and serum free alpha-subunit (SU) with low levels of LH and testosterone (T) were found. Immunostaining showed the presence of alpha-SU, FSH-beta and LH-beta subunits. LHRH analogue (buserelin) was administered in a pulsatile manner, by portable computerized infusion pump sc for ten days. During the first 24 h of treatment FSH, LH (p less than 0.001) and T (p less than 0.01) rose significantly. Ten days later, the expected desensitization phenomenon did not occur, but further increases of T (8.4 +/- 2.6, mean +/- SD, vs 17.4 +/- 4.1 nmol/l, p less than 0.001) and FSH (58.9 +/- 9.6 vs 70.7 +/- 3.8 mlU/ml, p less than 0.001) were registered. LH decreased (12.5 +/- 2.4 vs 7.1 +/- 0.6 mlU/ml, p less than 0.001) at day 10, but remained higher than basal level (5.0 +/- 0.6, p less than 0.001). Free alpha-SU also rose (2.8 +/- 0.4 vs 4.4 +/- 1.7 mlU/ml, p less than 0.001) after ten days of treatment. The chronic stimulatory effect of analogue on LH with a lack of desensitization suggests tumorous secretion despite a partially preserved negative feedback of testosterone. Low basal LH levels, in some patients with FSH secreting tumors may not be due to tumor mass effect, but rather may be the consequence of altered LH production and/or secretion by the tumor. Although buserelin may not have a therapeutic effect, it is of use in differential diagnosis of hypergonadotropinemia.

Elevated adrenocorticotropic hormone and cortisol levels in a patient with medullary carcinoma of the thyroid containing ectopic immunoreactive corticotropin-releasing hormone and bombesin

Pituitary adrenocorticotropic hormone-dependent Cushing's syndrome due to ectopic production of corticotropin-refeasing hormone (CRH) or bombesin (gastrin-releasing peptide) is an extremely rare cause of pituitary adrenocorticotropic hormone (ACTH) hypersecretion. We report a patient with elevated ACTH and cortisol levels due to ectopic secretion of both bombesin and CRH by metastatic medullary carcinoma of the thyroid (MCT). A 45-year-old man was investigated because of diabetes insipidus and visual field disturbances due to suprasellar metastasis of the MCT. On physical examination, he was a chronically ill man with a body mass index of 18.5 and was darkly pigmented but without other features typical of Cushing's syndrome. Hypogonadotropic hypogonadism, thyroid-stimulating hormone (TSH) deficiency, and hyperprolactinemia were due to pituitary stalk disorder, in light of these deficiencies, we were surprised to find elevated plasma ACTH, cortisol, and growth hormone (GH) levels throughout the day. Plasma ACTH at 9AM was 118 pg/ml and plasma cortisol was 859 nmol/L. At 12PM, ACTH was 89 pg/ml whereas plasma cortisol was 540 nmol/L. Urinary 17 OH CS were elevated (38 nmol/24 hr). The mean of the four-point day curve for GH was elevated. Plasma electrolytes were normal. The presence of both CRH and bombesin was documented by immunocytologic studies in the metastases (lymph node and suprasellar biopsy). ACTH was not found in any of the metastases. Because of the close proximity of the suprasellar metastasis to the portal pituitary circulation, CRH and bombesin could have been readily provided to the pituitary corticotrophs.

Discordance between growth hormone responses after growth hormone-releasing hormone (GHRH) and insulin hypoglycemia in ectopic GHRH syndrome

Dynamic studies of growth hormone (GH) secretion were performed in two patients with ectopic GHRH syndrome. Patient 1 (female, 33 years old) had a growth hormone releasing hormone (GHRH) producing carcinoid of the lung with clinical features of acromegaly while patient 2 (50 years old male) had small cell carcinoma of the lung without acromegaly. Insulin hypoglycemia stimulated GH secretion in both patients (i.e. from a basal level of 10 mU/l to 48 mU/l in patient 1, while the respective values in patient 2 were 5 mU/l and 61 mU/l), TRH acutely stimulated GH in both patients. Synthetic GHRH 1-29 (KABI) i.v. bolus 100 micrograms did not stimulate GH release in either patient (i.e. basal GH 14 mU/l and peak 18 mU/l (patient 1); basal GH 4.6 mU/l and peak 8.8 mU/l (patient 2). It is concluded that: 1. prolonged pituitary exposure to GHRH is associated with chronic GH hypersecretion with or without clinical acromegaly; 2. GH response to TRH may be mediated at the pituitary level and results from prolonged exposure to GHRH; 3. the discordant response of GH after GHRH and insulin induced hypoglycemia might suggest the involvement (at least partially) of somatostatin in the mechanism of GH release after hypoglycemia and after GHRH.