Hepatic Stellate Cells and Liver Retinoid Content in Alcoholic Liver Disease in Humans

Body retinoids are stored in the lipid droplets of hepatic stellate (Ito) cells. In chronic liver disease, the stellate cells differentiate into myo-fibroblast-like cells, a process whereby they lose their retinoid-con-taining lipid droplets. We studied the relation between liver retinoid content, the number of lipid droplets per stellate cell, and the number of stellate cells per mm² in human alcoholic liver disease. Semithin sections of liver biopsies from normal subjects and patients with early (steatosis, inflammation, and mild fibrosis) and late (cirrhosis and cirrhosis with acute alcoholic hepatitis) alcoholic liver disease were morphometrically evaluated. Liver retinoid content was determined by HPLC. In normal patients, liver retinoid content was 901 ± 213 lU/g of liver (mean ± SEM). There was a decrease in liver retinoid content in early alcoholic liver disease (409 ± 50 IU/g) and a further reduction in cirrhosis (153 ± 50 IU/g). In patients with acute alcoholic hepatitis, retinoid content was strikingly low (5.2 ± 1.8 IU/g). There was a progressive decrease in the number of stellate cells per mm² associated with progressive liver damage. We found a fair correlation between the number of stellate cells per mm² and liver retinoid content in all patient groups (overall correlation: 0.71). In normal subjects, the mean number of lipid droplets per stellate cell was 7.4 ± 0.7. In patients with early alcoholic liver disease and in patients with alcoholic cirrhosis, this value was increased to 13.6 ± 0.8 and 10.4 ± 2.0, respectively. In patients with acute alcoholic hepatitis, only a few lipid droplets were present (4.2 ± 0.5). There was a good correlation between liver retinoid content and mean number of lipid droplets in normal patients (r= 0.58). In alcoholic cirrhosis, however, correlation was poor (r= 0.34). In early alcoholic liver disease, the correlation was absent (r= 0.004). In conclusion, the major finding of our study is that the correlation between the mean number of lipid droplets per stellate cell and liver retinoid content varies according to the hepatic pathology considered. Marked lipid droplet accumulation occurs in stellate cells in early alcoholic liver disease and, to a lesser extent, in alcoholic cirrhosis, but there is no correlation between the mean number of lipid droplets per stellate cell and liver retinoid content. Therefore, not retinoids but probably lipids are responsible for the accumulation of lipid droplets. We also find that there is a fair correlation between the number of stellate cells per mm² and liver retinoid content in all patient groups. Finally, we confirm the decrease in hepatic retinoid content that occurs in alcoholic liver disease in humans, even at the early stages of the disease.     

History, heterogeneity, developmental biology, and functions of quiescent hepatic stellate cells

In 1876, von Kupffer described liver Sternzellen (star-shaped cells). The functions of these cells remained enigmatic for 75 years until Ito observed lipid-containing perisinusoidal cells in human liver. In 1971, Wake demonstrated that the Sternzellen of von Kupffer and the fat-storing cells described by Ito were identical. Wake also established that these cells were important sites of vitamin A storage. Soon thereafter, Kent and Popper demonstrated that the stellate cells were intimately linked to the pathogenesis of hepatic fibrosis. Since then, these cells have been studied in detail. Quiescent stellate cells represent 5-8% of the total number of liver cells. They play a cardinal role in storage and controlled release of retinoids. They control extracellular matrix (ECM) turnover in the space of Disse by secreting the correct amounts of a limited number of ECM molecules, and by releasing matrix metalloproteinases and their inhibitors. By virtue of their long cytoplasmic processes, quiescent stellate cells presumably contribute to the control of blood flow through the sinusoidal capillaries. They are important sources of paracrine, autocrine, juxtacrine, and chemoattractant factors that maintain homeostasis in the microenvironment of the hepatic sinusoid.     

The predictive value of the heart rate variability‐derived Analgesia Nociception Index in children anaesthetized with sevoflurane: An observational pilot study

Background

The heart rate variability (HRV)‐derived Analgesia Nociception Index (ANI?) is a continuous noninvasive tool to assess the nociception/antinociception balance in unconscious patients. It has been shown to be superior to haemodynamic variables in detecting insufficient antinociception in children, while little is known about its predictive value.

Methods

The primary objective of this prospective observational pilot study in paediatric surgical patients under sevoflurane anaesthesia was to compare the predictive value of the ANI and heart rate to help decide to give additional opioids. The paediatric anaesthesiologist in charge was blinded to ANI values.

Results

In patients with an ANI value <50 (indicating insufficient antinociception) at the moment of decision, ANI values dropped from ±55 (indicating sufficient antinociception) to ±35, starting 60 s before decision. Within 120 s after administration of fentanyl (1 μg/kg), ANI values returned to ±60. This phenomenon was only observed in the ANI values derived from HRV data averaged over 2 min. Heart rate remained unchanged. In patients with ANI values ≥50 at the time of decision, opioid administration had no effect on ANI or heart rate. The same accounts for morphine for postoperative analgesia and fentanyl in case of intraoperative movement.

Conclusions

This study provides evidence of a better predictive value of the ANI in detecting insufficient antinociception in paediatric surgical patients than heart rate. The same accounts for depicting re‐establishment of sufficient antinociception after opioid drug administration.

Significance

In paediatric surgical patients anaesthetized with sevoflurane, the heart rate variability‐derived Analgesia Nociception Index (ANI) appears to be a better predictor of insufficient antinociception than heart rate. The ANI also appears to depict re‐establishment of sufficient antinociception better than heart rate.

     

A Randomized,Double-Blind,Parallel Study to Evaluate the Dose-Response of Three Different Vitamin D Treatment Schemes on the 25-Hydroxyvitamin D Serum Concentration in Patients with Vitamin D Deficiency

Many people worldwide are vitamin D (VTD) deficient or insufficient, and there is still no consensus on the dose of VTD that should be administered to achieve a 25(OH)D concentration of 20 or 30 ng/mL. In this study, we aimed to determine an adapted supplementation of VTD able to quickly and safely increase the vitamin D status of healthy adults with low 25(OH)D. One hundred and fifty (150) subjects were randomized into three groups, each to receive, orally, a loading dose of 50,000, 100,000 or 200,000 IU of VTD3 at Week 0, followed by 25,000, 50,000 or 100,000 IU at Week 4 and Week 8. Whereas 25(OH)D baseline values were not different between groups (p = 0.42), a significant increase was observed at Week 12 (p < 0.0001) with a mean change from baseline of 7.72 ± 5.08, 13.3 ± 5.88 and 20.12 ± 7.79 ng/mL. A plateau was reached after eight weeks. No related adverse event was recorded. This study demonstrated a linear dose-response relationship with an increase in 25(OH)D levels proportional to the dose administered. In conclusion, a loading dose of 200,000 IU VTD3 followed by a monthly dose of 100,000 IU is the best dosing schedule to quickly and safely correct the VTD status.     

The paddy, the vector and the caregiver: lessons from an ecosystem approach to irrigation and malaria in Northern Côte d'Ivoire

Malaria is one of the most serious public health problems in the world. For the last few decades, numerous studies have focused on the potential links between environmental transformations (such as the expansion of irrigation) and malaria occurrence. Most of these studies have been based on relatively simple models outlining the interactions of the host-vector-parasite triad. In this paper, we investigate the links between the intensification of irrigated rice cultivation and malaria. In an attempt to complement biomedical and entomological approaches we propose a model that recognises the influence of human-vector contacts on transmission processes, but stresses the importance of taking into consideration socio-economic and cultural factors in the management of disease episodes, and how these can be affected by transformations of natural resource management strategies. Using a case study in Northern C?te d'Ivoire, we investigated the complex mechanisms by which agriculture-generated changes in ecosystems and socio-economic organisation influence disease risks and produce new scenarios in the management of disease. Our results show that the socio-economic transformation and gender repositioning induced, or facilitated, by the intensification of lowland irrigated rice cultivation influence the health care system for malaria in the study area. They lead to a reduction of the capacity of women to manage malaria episodes among children and influence their vulnerability to the disease. We argue that these elements contribute to higher malaria prevalence in villages involved in double cropping of rice annually.     

Stent placement or brachytherapy for palliation of dysphagia from esophageal cancer: a prognostic model to guide treatment selection

BACKGROUND: Brachytherapy was found to be preferable to metal stent placement for the palliation of dysphagia because of inoperable esophageal cancer in the randomized SIREC trial. The benefit of brachytherapy, however, only occurred after a relatively long survival. The objective is to develop a model that distinguishes patients with a poor prognosis from those with a relatively good prognosis. METHODS: Survival was analyzed with Cox regression analysis. Dysphagia-adjusted survival (alive with no or mild dysphagia) was studied with Kaplan-Meier analysis. Patient data is from the multicenter, randomized, controlled trial (SIREC, n = 209) and a consecutive series (n = 396). Patients received a stent or single-dose brachytherapy. RESULTS: Significant prognostic factors for survival included tumor length, World Health Organization performance score, and the presence of metastases (multivariable p < 0.001). A simple score, which also included age and gender, could satisfactorily separate patients with a poor, intermediate, and relatively good prognosis within the SIREC trial. For the poor prognosis group, the difference in dysphagia-adjusted survival was 23 days in favor of stent placement compared with brachytherapy (77 vs. 54 days, p = 0.16). For the other prognostic groups, brachytherapy resulted in a better dysphagia-adjusted survival. CONCLUSIONS: A simple prognostic score may help to identify patients with a poor prognosis in whom stent placement is at least equivalent to brachytherapy. If further validated, this score can provide an evidence-based tool for the selection of palliative treatment in esophageal cancer patients.     

Toward the development of a test for growth hormone (GH) abuse: a study of extreme physiological ranges of GH-dependent markers in 813 elite athletes in the postcompetition setting

There is a need to develop a test to detect GH abuse by elite athletes. Measured levels of GH in blood or urine, however, provide little information on the GH-IGF-I axis. Previous studies have identified a series of indirect markers of GH action that are markedly altered by the administration of GH, but to a lesser degree by acute exercise. This study was undertaken to determine the physiological range of these GH-dependent variables in elite athletes after a competitive event to determine whether such values differ from resting values in normal and athletic subjects and to establish whether any adjustments to this range are required on the basis of age, gender, demographic characteristics, or the nature of the exercise performed. Serum samples were collected from 813 elite athletes (537 males and 276 females; age range, 17-64 yr) from 15 sporting disciplines within 2 h of completion of a major competitive event. IGF-I, IGF-binding protein 2 (IGFBP-2), IGFBP-3, acid-labile subunit, and the bone and soft tissue markers, osteocalcin, carboxyl-terminal propeptide of type I procollagen, carboxyl-terminal cross-linked telopeptide of type I collagen, and procollagen type III were measured. Sporting category, gender, age, height, weight, body mass index (BMI), and racial group of the athlete were documented, and results were compared both to normative data and to values obtained from elite athletes under resting conditions. Forty-one percent of IGF-I values in male athletes and 41% of values in female athletes were above the upper limits of 99% reference ranges derived from resting values in a normal population. Postcompetition levels of all variables except carboxyl-terminal propeptide of type I procollagen and carboxyl-terminal cross-linked telopeptide of type I collagen differed from resting values. There was a consistent age-dependent fall in measured levels of all variables (P < 0.0001) with the exception of IGFBP-2, which increased with age (P < 0.0001). BMI, but not height, exerted a small, but significant, influence on several variables. After adjustment for age, there were no significant differences in the levels of any of the measured variables between sporting categories. IGFBP-2 and IGFBP-3 were lower in 35 black athletes compared with those in 35 white athletes matched for age, gender, height, BMI, and sporting category. We have demonstrated that there are predictable age-dependent levels of GH-dependent markers in elite athletes that are consistent even at the extremes of physical exertion and that these are independent of sporting category. Normative data applicable to white athletes are provided. This provides important groundwork for the development of a test for GH abuse, although these values may be specific for the reagents and assays used.