Serum profiles of insulin-like growth factors and their binding proteins in adults with growth hormone receptor deficiency treated with insulin like growth factor I

Six adult patients with growth hormone receptor deficiency (GHRD) (2 men, 4 women) with an identical defect in the growth hormone receptor (GHR) gene, were treated with recombinant human insulin-like growth factor I (IGF-I), 40 μgikg S.C. twice daily, for 7 days. Serum concentrations of IGF peptide and IGF binding protein-3 (IGFBP-3) were measured by specific radioimmunoassays; serum IGFBPs were also measured by Western ligand blotting. The size distribution of both IGF-I and IGF-II was measured in serum following size-exclusion fast-performance liquid chromatography. IGF-I treatment resulted in a normalization of serum IGF-I levels on days 1–7 of treatment and a decrease in serum IGF-II levels. The fall in IGF-II levels and the simultaneous rise in IGF-I levels, however, resulted in an unchanged total serum IGF level. The low IGFBP-3 values did not significantly change during treatment, whereas there was a slight increase in IGFBP-2 levels. Preliminary analysis of size-fractionated sera suggested an increase in IGF-I levels in the 40 and 150 kDa regions at the expense of IGF-II levels. The results suggest that despite the failure of IGF-I treatment to increase IGFBPs significantly, serum IGFBP concentrations were sufficient to maintain normal levels of IGF-I. 0 Laron syndrome, growth hormone receptor deficiency, insulin-like growth factors, insulin-like growth factor binding protein     

Ecstasy cannot be assumed to be 3,4-methylenedioxyamphetamine (MDMA)

LINKED ARTICLES

This is a rebuttal by the authors (Green et al., pp. 1523–1536 of this issue) to a commentary by Parrott, pp. 1518–1520 of this issue. To view the article by Green et al. visit http://dx.doi.org/10.1111/j.1476-5381.2011.01819.x. To view the commentary by Parrott visit http://dx.doi.org/10.1111/j.1476-5381.2012.01941.xWe thank Prof Parrott (Parrott 2012) for his interest in our review (Green et al., 2012). Our main aim was to discuss the problems that arise in interpreting data obtained when administering 3,4-methylenedioxymethamphetamine (MDMA) to experimental animals in terms of possible clinical consequences and vice versa, not to disparage the evidence that Ecstasy is neurotoxic in humans. We presented evidence that the pharmacokinetics of MDMA in rats and primates are fundamentally different from the pharmacokinetics of the drug in humans. Because the plasma half-life of the drug in rats is 10 times shorter than in humans, the acute adverse events in rats may be minimal compared with those in humans, and this includes body temperature and endocrine changes. Conversely, the rapid metabolism of the drug in rats to form neurotoxic metabolites may result in more severe long-term effects in that species than those that may occur in humans.We had no intention of suggesting that there was no evidence for some recreational Ecstasy users presenting with evidence of 5-HT neurotoxicity, albeit it is clear from the literature that some of this evidence remains open to several interpretations. What we did claim was that pure 3,4-methylenedioxymethamphetamine (MDMA) taken alone was unlikely to cause 5-HT neurotoxicity in man. Here we must emphasize the term MDMA, as it is crucial to our discussion. Parrott, in contrast, uses the term ‘Ecstasy/MDMA’ several times when discussing neurotoxicity (Parrott, 2012). This association of Ecstasy with MDMA is one of the major problems of translation that we addressed. The Ecstasy tablet that most recreational users buy and ingest is not necessarily MDMA. Indeed, in many cases, it clearly is not. The tablet is often adulterated with other compounds, and one investigation identified no less than 14 substances other than MDMA in Ecstasy tablets, which users nevertheless presumably believed contained only MDMA (Vogels et al., 2009). Many of the adulterants identified were also psychoactive and included compounds structurally related to MDMA such as 3,4-methylenedioxyethylamphetamine and 2-methylamino-1-(3,4-methylenedioxyphenyl)butane, which have poorly researched pharmacology and toxicology. In addition, most recreational users of Ecstasy also knowingly ingest other psychoactive compounds such as alcohol and cannabis. Alcohol, for example, alters the pharmacokinetics of MDMA (Hamida et al., 2009). While, as Parrott states, clinical studies have attempted to allow for these confounding factors in any examination of the physical and psychological effects of MDMA in humans, such analysis is always limited not only by the other compounds the evaluators are unaware of, but also drugs perhaps not even considered to be relevant by the user and therefore not disclosed. It is unlikely that coffee and ‘energy drinks’ such as Red Bull are always disclosed, but there is now good preclinical evidence that caffeine, which incidentally has also been found as an adulterant in Ecstasy tablets, enhances both the hyperthermia and neurotoxicity induced in rats by MDMA (Camarasa et al., 2006; Vanattou-Saïfoudine et al., 2010). And this brings us to the crux of the problem and weakness of all the clinical data cited by Parrott (2012). A basic tenet of all good clinical pharmacology is accurate knowledge of the doses administered, frequency of administration and any confounding factors such as other drugs being consumed. None of these data are available with any precision in the clinical studies quoted. Of course one has some indication as to dose (although as Vogels et al., (2009) reported, the dose contained in illicitly obtained tablets is highly variable) and frequency of drug ingestion, but this information is generally obtained from the user whose recall is likely to be limited or who decides to obfuscate. Crucially, the information can never take into account the problem of drug tablet adulteration. The fact that hair or urine samples detect MDMA merely shows the user has consumed the drug, not how much or when or what other drugs were taken concurrently.We never suggested that MDMA exposure was not going to be associated with physical or psychological change. However such changes are not necessarily associated with long-term neurotoxic damage. We have shown that long-term behavioural effects can occur in rats both with and without 5-HT neurotoxicity (Fone et al., 2002; Bull et al., 2003; Rodsiri et al., 2011). It is interesting that Parrott approvingly quotes the Verheyden et al. (2003) study in support of his contention that neurotoxic damage has occurred. Because this study noted that the majority of persons reporting chronic psychiatric problems reported ‘improved mental health’ after quitting the drug, this surely allows us to conclude that the drug had produced subacute changes rather than any that could be associated with long-term neurotoxic damage.A further limitation to any clinical study is that one cannot perform prospective studies with the aim of investigating whether long-term neurotoxic events occur, so weaknesses arise with regard to any psychological abnormalities observed. Are persons with high risk of psychiatric problems more likely to misuse the drug, or does the drug induce changes in high-risk individuals? If high risk also happened to be associated with 5-HT abnormalities in the brains, then any conclusion that MDMA has induced neurotoxicity is spurious.We most certainly did not suggest that MDMA acted as a neurotoxin only under conditions of severe hyperthermia as is stated by Parrot in his sixth paragraph (Parrott, 2012). We have been involved in many studies on the effects of MDMA on body temperature in rats (see Docherty and Green, 2010) including one that demonstrated that neurotoxicity can occur in the absence of hyperthermia (O''Shea et al., 1998) and another that showed that hyperthermia worsens neurotoxic damage (Green et al., 2004). In our review, what we did propose was that because of the very different pharmacokinetics of MDMA in rats and humans, it is probable that humans would suffer serious or fatal adverse events at plasma levels below those likely to be required to induce 5-HT neurotoxicity.We emphasize again that we are not denying the clinical observations reviewed by Parrott, but conclude that the effects seen cannot be ascribed solely to the effects of MDMA, as he seems to be proposing. We also repeat our contention that MDMA in combination with other drugs may induce neurotoxicity and this could be said to be supported by the clinical studies quoted by Parrott.Finally, we can but assume that Parrott concurs with our principal conclusion that ‘the doses currently being used to investigate the possible therapeutic benefits of MDMA are unlikely to produce any severe acute or importantly any long-term neurotoxic damage in the human brain’ as he used such a dose (100 mg or approximately 1.4 mg·kg ⁻¹) in one of his recent studies in human volunteers (Parrott et al., 2011).     

Guinea pig MSEL-neurophysin. Sequence comparison of eight mammalian MSEL-neurophysins

The amino acid sequence of guinea pig MSEL-neurophysin has been determined using tryptic peptides derived from the performic acid-oxidized protein and staphylococcal proteinase peptides obtained from the reduced-carboxamidomethylated neur-ophysin. Guinea pig MSEL-neurophysin consists of a 93-residue polypeptide chain that shows 12 substitutions and 2 deletions when compared to bovine MSEL-neurophysin. It displays the highest number of variations among known mammalian MSEL-neurophysins. These variations are mainly found in the C-terminal region (residues 88–93). Moreover guinea pig MSEL-neurophysin, like rat homologous protein, exhibits substitutions in positions 2, 5, 29 and 81 and lacks an arginine in the penultimate position. Comparison between eight mammalian MSEL-neurophysins reveals a highly conserved region (residues 1 to 88) and a hypervariable region (residues 89 to 93/95). On the other hand the eight species examined are endowed with arginine vasopressin except pig, which has a lysine vasopressin. In the vasopressin-MSEL-neurophysin precursor, the hormonal moiety and the MSEL region of neurophysin (residues 1–9) are encoded by a common exon in ox, rat and man; it can be concluded that this exon is evolutionarily conservative in contrast to the one encoding the C-terminal region of MSEL-neurophysin.     

Oral facial clefts and gene polymorphisms in metabolism of folate/one‐carbon and vitamin A: a pathway‐wide association study

An increased risk of facial clefts has been observed among mothers with lower intake of folic acid or vitamin A around conception. We hypothesized that the risk of clefts may be further moderated by genes involved in metabolizing folate or vitamin A. We included 425 case‐parent triads in which the child had either cleft lip with or without cleft palate (CL/P) or cleft palate only (CPO), and no other major defects. We analyzed 108 SNPs and one insertion in 29 genes involved in folate/one‐carbon metabolism and 68 SNPs from 16 genes involved in vitamin A metabolism. Using the Triad Multi‐Marker (TRIMM) approach we performed SNP, gene, chromosomal region, and pathway‐wide association tests of child or maternal genetic effects for both CL/P and CPO. We stratified these analyses on maternal intake of folic acid or vitamin A during the periconceptional period. As expected with this high number of statistical tests, there were many associations with P‐values<0.05; although there were fewer than predicted by chance alone. The strongest association in our data (between fetal FOLH1 and CPO, P=0.0008) is not in agreement with epidemiologic evidence that folic acid reduces the risk of CL/P in these data, not CPO. Despite strong evidence for genetic causes of oral facial clefts and the protective effects of maternal vitamins, we found no convincing indication that polymorphisms in these vitamin metabolism genes play an etiologic role. Genet. Epidemiol. 2009. © 2008 Wiley Liss, Inc.     

The M-OVIN study: does switching treatment to FSH and / or IUI lead to higher pregnancy rates in a subset of women with world health organization type II anovulation not conceiving after six ovulatory cycles with clomiphene citrate – a randomised controlled trial

Background

Clomiphene citrate (CC) is first line treatment in women with World Health Organization (WHO) type II anovulation and polycystic ovary syndrome (PCOS). Whereas 60% to 85% of these women will ovulate on CC, only about one half will have conceived after six cycles. If women do not conceive, treatment can be continued with gonadotropins or intra-uterine insemination (IUI). At present, it is unclear for how many cycles ovulation induction with CC should be repeated, and when to switch to ovulation induction with gonadotropins and/or IUI.

Methods/Design

We started a multicenter randomised controlled trial in the Netherlands comparing six cycles of CC plus intercourse or six cycles of gonadotrophins plus intercourse or six cycles of CC plus IUI or six cycles of gonadotrophins plus IUI.Women with WHO type II anovulation who ovulate but did not conceive after six ovulatory cycles of CC with a maximum of 150 mg daily for five days will be included.Our primary outcome is birth of a healthy child resulting from a pregnancy that was established in the first eight months after randomisation. Secondary outcomes are clinical pregnancy, miscarriage, multiple pregnancy and treatment costs. The analysis will be performed according to the intention to treat principle. Two comparisons will be made, one in which CC is compared to gonadotrophins and one in which the addition of IUI is compared to ovulation induction only. Assuming a live birth rate of 40% after CC, 55% after addition of IUI and 55% after ovulation induction with gonadotrophins, with an alpha of 5% and a power of 80%, we need to recruit 200 women per arm (800 women in total).An independent Data and Safety Monitoring Committee has criticized the data of the first 150 women and concluded that a sample size re-estimation should be performed after including 320 patients (i.e. 80 per arm).

Discussion

The trial will provide evidence on the most effective, safest and most cost effective treatment in women with WHO type II anovulation who do not conceive after six ovulatory cycles with CC with a maximum of 150 mg daily for five days. This evidence could imply the need for changing our guidelines, which may cause a shift in large practice variation to evidence based primary treatment for these women.

Trial registration number

Netherlands Trial register NTR1449

     

Inpatient admissions for interventional radiology: philosophy of patient management

As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.     

Plasma concentration of folate as a biomarker for the intake of fruit and vegetables: the Hordaland Homocysteine Study

BACKGROUND: Nutritional biomarkers may be used to assess dietary exposure without the errors commonly associated with self-reported dietary data. OBJECTIVE: The objective was to examine the association between plasma folate and intake of folate, fruit, and vegetables in a large cohort of healthy adults consuming foods that had not been fortified with folic acid. DESIGN: The present study population included 5533 middle-aged (47-49 y) and old (71-74 y) subjects from the Hordaland Homocysteine Study. The participants completed a food-frequency questionnaire and provided blood samples for chemical analyses. RESULTS: We observed a significant difference in plasma concentrations of folate across increasing quartiles of fruit, vegetable, and orange juice consumption. The difference in plasma folate between the highest and lowest quartiles was 1.97 (95% CI: 1.86, 2.07) nmol/L for fruit intake, 1.79 (95% CI: 1.69, 1.89) nmol/L for vegetable intake, and 2.69 (95% CI: 2.51, 2.87) nmol/L for orange juice intake. A significant inverse relation was observed across increasing quartiles of milk and bread intakes. The difference between the highest and lowest quartiles was -1.03 (95% CI: -1.13, -0.92) nmol/L for milk and -1.60 (95% CI: -1.69, -1.50) nmol/L for bread. CONCLUSION: Plasma folate concentration may be a useful biomarker for the intake of fruit and vegetables in populations consuming unfortified food products. The association can be attenuated by and should be corrected for individual intake of folic acid supplements.     

The controversy over homocysteine and cardiovascular risk

Elevated plasma total homocysteine (tHcy) is a risk factor for occlusive cardiovascular disease (CVD). This concept is based on the observations of premature vascular disease in patients with homocystinuria, the relation between tHcy and both clinical CVD as well as preclinical atherosclerotic disease, the relation between tHcy in children and CVD in their parents or relatives, and reduction in CVD or surrogate endpoints after tHcy-lowering intervention with B vitamins. Plausible mechanisms include the in vivo interference with nitric oxide-dependent reactive vasodilatation. Some observations have raised questions about tHcy as a risk factor. 1) Some prospective studies showed a weak relation or no relation between tHcy and CVD. 2) Several traditional risk factors are associated with tHcy and may confound the relation between tHcy and CVD. 3) tHcy is related to renal function, and hyperhomocysteinemia may reflect early nephrosclerosis. 4) The C677T transition of the methylenetetrahydrofolate reductase gene causes a moderate increase in tHcy but no or only minor increased CVD risk. However, the strength of some of these arguments can be questioned because there is increasing evidence that tHcy is a proximate risk factor provoking the acute event, it strongly interacts with traditional risk factors, and it may predict CVD or death in patients with chronic renal failure. Furthermore, the studies of the C677T polymorphism lack statistical power, and the TT genotype may even modulate CVD risk independently of homocysteine. Thus, only placebo-controlled intervention studies with tHcy-lowering B vitamins and clinical endpoints can provide additional valid arguments for the debate over whether tHcy is a causal CVD risk factor.