A recursive-partitioning model for blood–brain barrier permeation

A series of bagged recursive partitioning models for log(BB) is presented. Using a LGO-CV, three sets of physical property descriptors are evaluated and found to have Q2 values of 0.51 (CPSA), 0.53 (Ro5x) and 0.53 (MOE). Extrapolating these models to Pfizer chemical space is difficult due to P-glycoprotein (P-gp) mediated efflux. Low correlation coefficients for this test set are improved (R2 = 0.39) when compounds known to be P-gp substrates or statistical extrapolations are removed. The use of simple linear models for specific chemical series is also found to improve the correlation over a limited chemical space.

Diagnosing erectile dysfunction: instruments for endocrine diagnosis

Endocrine factors represent an important and potentially treatable cause of sexual dysfunction. The availability of a correct endocrinological diagnosis allows correct identification of most cases of sexual dysfunction in which the endocrine apparatus is involved. Not only the most frequent causes of endocrine sexual dysfunction, such as hypogonadism and hyperprolactinaemia, but almost all extra-gonadal endocrinopathies (hyper-and hypothyroidism, hyper- and hypocortisolism, steroidal secreting tumours, etc.) may have importance to a greater or lesser extent in sexual function. It is, therefore, necessary that the diagnostic process for sexual dysfunctions of an endocrine nature be as integrated and wide as possible, especially as such pathologies are normally extremely responsive to medical or surgical therapy.

The therapeutic dilemma: How to use tadalafil

Tadalafil, a type 5 phosphodiesterase inhibitor, is a new and effective therapy for erectile dysfunction. It has unique pharmacokinetic properties in its drug class, which also includes sildenafil and vardenafil. It is also well tolerated with few side-effects, and can be used in difficult patients such as neuropaths or diabetics.

The effect of adding nitrous oxide on MAC of sevoflurane combined with two target-controlled concentrations of remifentanil in women

BACKGROUND AND OBJECTIVE

The aim of this prospective, randomized, double-blind study was to determine the effects of adding nitrous oxide on sevoflurane requirement for blunting sympathetic responses after surgical incision combined with two different target-controlled concentrations of remifentanil (1 and 3 ng mL(-1)) in female.

METHODS

102 female patients, aged 20-50 yr, ASA I, undergoing general anaesthesia for elective abdominal surgery were enrolled and randomly allocated to receive sevoflurane anaesthesia alone (Group A, n=53), or with the addition of 60% nitrous oxide (Group N, n=49). Patients of both groups were further assigned to receive a target-controlled remifentanil infusion with an effect-site concentration of either 1 ng mL(-1) (Group N1, n=27; Group A1, n=30), or 3 ng mL(-1) (Group N3, n=22; Group A3, n=23). Sympathetic responses to surgical incision were determined after a 20-min period of stable end-tidal sevoflurane and target-controlled remifentanil concentrations. Predetermined end-tidal sevoflurane concentrations and minimum alveolar concentration (MAC) for each group were determined using an up-and-down sequential allocation technique.

RESULTS

The MAC of sevoflurane was 3.96% (95% confidence interval, CI95: 3.69-4.23%) in Group A1 and 1.2% (CI95: 0.9-1.3%) in Group N1 (P < 0.01), while in Groups A3 and N3 the MAC of sevoflurane was 0.36% (CI95: 0.24-0.47%) and 0.18% (CI95: 0.1-0.3%), respectively (P < 0.05).

CONCLUSION

Adding 60% nitrous oxide reduces the MAC of sevoflurane by 70% when using a remifentanil concentration of 1 ng mL(-1) and 50% when using a remifentanil concentration of 3 ng mL(-1).

An Anopheles gambiae salivary gland promoter analysis in Drosophila melanogaster and Anopheles stephensi

Regulatory regions driving gene expression in specific target organs of the African malaria vector Anopheles gambiae are of critical relevance for studies on Plasmodium-Anopheles interactions as well as to devise strategies for blocking malaria parasite development in the mosquito. In order to identify an appropriate salivary gland promoter we analysed the transactivation properties of genomic fragments located just upstream of the An. gambiae female salivary gland-specific genes AgApy and D7r4. An 800 bp fragment from the AgApy gene directed specific expression of the LacZ reporter gene in the salivary glands of transgenic Anopheles stephensi. However, expression levels were lower than expected and the transgene was expressed in the proximal-rather than in the distal-lateral lobes of female glands. Surprisingly, a promoter fragment from the D7r4 gene conferred strong tissue-specific expression in Drosophila melanogaster but only low transcription levels in transgenic An. stephensi. These results imply a certain conservation of gland-specific control elements between the fruit fly and the mosquito suggesting that an increased degree of complexity, probably connected to the evolution of haematophagy, underlies the regulation of tissue-specific expression in mosquito female salivary glands.

Androgens and fertility

Androgens play a pivotal role in the development of the male reproductive tract. The spermatogenesis requires high levels of intratesticular testosterone secreted by the Leydig cells. Testosterone exerts its action through the androgen receptor (AR), which is located both in the cytoplasm and in the nucleus of cells in the target tissue. Severe defects of the AR may result in abnormal male sexual development, while more subtle modifications can be a potential cause of male infertility. Low circulating levels of testosterone can be found in 20-30% of infertile men, but administration of testosterone or gonadotropins does not result in improved sperm production. Abuse of anabolic steroids is a frequent cause of male infertility, and substances such as endocrine disruptors can alter male fertility through an anti androgenic action.

Psychosocial issues of ART in aging male

The role of androgens in human sexuality as regards the mechanism of erection and the pathogenesis of impotence is under debate. In addition, it is difficult to define the psychosocial impact of both hypogonadism and androgen replacement. However, sexual hormones largely influence mood, well-being, and quality of life. For this reason, despite the methodological difficulties of assessment, testosterone replacement has a deep impact on the social, psychological and sexual life of the treated patient. Considering the obvious characteristic of testosterone as an hormone, it appears evident that the endocrinologist is the unique experienced specialist able to diagnose and treat the hypogonadal men, monitoring potential side effects and following the psychosocial issues of androgen therapy.

Intestinal anisakiasis in Italy: case report

A case of intestinal anisakiasis caused by Anisakis sp. larva type I in a woman from Italy who consumed raw marinated anchovies, is reported. The diagnosis was based on the morphological features characteristic of anisakid larval stages, which were readily recognized in a large granuloma removed after emergency surgical treatment.

Hemolytic crisis in a non-ketotic and euglycemic child with glucose-6-phosphate dehydrogenase deficiency and onset of type 1 diabetes mellitus

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy and hemolytic anemia can be triggered by many drugs, by the ingestion of fava beans, and by metabolic imbalances. Nonetheless, only sporadic reports of hemolytic anemia due to G6PD deficiency in patients with type 1 diabetes mellitus (DM1) have been reported to date. We describe an 8 year-old Sicilian boy who suffered from hemolytic anemia some days after admission for DM1. On admission, acid-base equilibrium was normal but 4 days later he presented hemolytic anemia with G6PD deficiency, confirmed by personal and family history and laboratory evaluation. We suggest that the hemolytic crisis in this patient was triggered by the relative hypoglycemia that followed insulin administration. The interference of acidosis, infections, drugs, food or other triggering agents was excluded. This report demonstrates that hemolysis may represent a possible complication of DM treatment in patients with G6PD deficiency and we recommend careful clinical surveillance in these patients.

Might erectile dysfunction be due to the thermolabile variant of methylenetetrahydrofolate reductase?

Hyperhomocysteinemia is considered one of the most important cardiovascular risk factors increasing considerably the risk of stroke and myocardial infarction. With respect to endothelial function, direct effects of hyperhomocysteinemia on vascular endothelial cells have been demonstrated through the reduction of endothelial nitric oxide production. In this paper, we report the case of a young man with homozygote genotype mutated with 5-methylenetetrahydrofolate reductase (MTHFR) thermolabile variant who, in the absence of relational stress, developed an erectile dysfunction (ED) refractory to the vasoactive type-V phosphodiesterase (PDE5) inhibitor therapy. After one month of treatment with 5 mg/day folic acid and 1000 microg/day cyanocobalamin, the patient restarted the assumption of 50 mg sildenafil, obtaining satisfying erections during sexual intercourse. We suggest that hyperhomocysteinemia may interfere with penile blood supply and, thus, be responsible for ED. If this relationship is confirmed, plasma levels and urinary homocysteine (HCy) should be evaluated in selected young patients with vascular ED. Furthermore, careful attention should be given to the risk of ED when dealing with this metabolic disturbance.

Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage

BACKGROUND

Sperm DNA integrity is essential for the accurate transmission of genetic information. The clinical significance of this assessment lies in its association with not only natural conception rates, but also the success of assisted reproduction technology (ART). It has been reported that sperm chromatin structure assay (SCSA) identified thresholds for negative pregnancy outcome after ART when the DNA fragmentation index (DFI), previously known as COMPalphat, was >30%.

METHODS

In a prospective clinical study, we examined 34 male infertile patients, the husbands of women undergoing conventional IVF or ICSI. SCSA and ART were carried out on semen aliquots taken from the same ejaculate. Fertilization rate, embryo quality and pregnancy rates were correlated to SCSA parameters, DFI and highly DNA stainable (HDS) cells.

RESULTS

No differences were seen in SCSA parameter values between patients initiating pregnancies and not doing so in either ICSI or conventional IVF. Pregnancies and normal delivery were obtained even with high levels of DFI.

CONCLUSIONS

There is still controversy over whether analytical techniques currently in use are able to identify the level of damage to spermatozoa. Large-scale studies should be conducted in different clinical settings to determine the effects of sperm DNA damage on the outcome of ART.

Nutritional, glycometabolic and genetic factors affecting menarcheal age in cystic fibrosis

Aims of this study were to investigate menarcheal age (MA) and menarcheal determinants in 25 girls with cystic fibrosis (CF) and to compare their MA with their respective mothers'. Patients' MA (13.3 +/- 1.1 yr) was on average significantly higher (p<0.0005) than that of the respective mothers (12.2 +/- 1.0 yr) and positively related to it (r=0.055, p<0.005). Six girls experienced menarche after 14.2 yr, ie after the uppest limit of their mothers' MA range. The only parameter which significantly differentiated these 6 patients from the remaining 19 cases was body mass percentile (BMP). Moreover, in the entire patient series a negative correlation was found between MA and BMP. None of the other clinical parameters correlated significantly with MA. No differences in terms of MA were detected in the subgroups of patients with a different glucose tolerance (GT) status and the 12 girls with a pathological GT were not older at menarche than those with normal GT. No correlations were found between either glucose or insulin areas during oral GT test and MA. In the subgroups of patients with a different genotype menarche occurred at a similar age, irrespectively of their genotype. On the basis of our findings we conclude that: a) a menarcheal delay of approximately 1 yr exists between CF girls and their mothers; b) menarcheal delay in CF is not related to either genotype or disease severity or glycometabolic status; c) the only two factors which are able to affect MA in CF are maternal MA and nutritional status.

Formation of stacked ER cisternae by low affinity protein interactions

The endoplasmic reticulum (ER) can transform from a network of branching tubules into stacked membrane arrays (termed organized smooth ER [OSER]) in response to elevated levels of specific resident proteins, such as cytochrome b(5). Here, we have tagged OSER-inducing proteins with green fluorescent protein (GFP) to study OSER biogenesis and dynamics in living cells. Overexpression of these proteins induced formation of karmellae, whorls, and crystalloid OSER structures. Photobleaching experiments revealed that OSER-inducing proteins were highly mobile within OSER structures and could exchange between OSER structures and surrounding reticular ER. This indicated that binding interactions between proteins on apposing stacked membranes of OSER structures were not of high affinity. Addition of GFP, which undergoes low affinity, antiparallel dimerization, to the cytoplasmic domains of non–OSER-inducing resident ER proteins was sufficient to induce OSER structures when overexpressed, but addition of a nondimerizing GFP variant was not. These results point to a molecular mechanism for OSER biogenesis that involves weak homotypic interactions between cytoplasmic domains of proteins. This mechanism may underlie the formation of other stacked membrane structures within cells.

Natural history of glucose tolerance, beta-cell function and peripheral insulin sensitivity in cystic fibrosis patients with fasting euglycemia

OBJECTIVE

The loss of pancreatic beta-cells is thought to be one of the principal causes of diabetes mellitus (DM) in cystic fibrosis (CF), but the role of peripheral insulin resistance (IR) in the pathogenesis of DM in CF remains unclear. The aim of this study was to evaluate whether eventual changes of glucose tolerance (GT) over time were associated with modifications of insulin secretion or sensitivity.

METHODS

Plasma glucose and insulin responses to an oral GT test (OGTT) were investigated and reinvestigated 13 Years later in 14 CF patients with initial and persistent fasting euglycemia and no history of insulin treatment. Insulin sensitivity (IS) at both tests was assessed on the basis of insulin and glucose levels both in the fasting state and during OGTTs.

RESULTS

From the 1st to the 2nd OGTT: (a) the prevalence of DM responses significantly increased; (b) the areas beneath the respective glucose and insulin curves significantly increased and decreased respectively; (c) IR and IS indices decreased and increased respectively, even in the patients who developed DM; (d) pulmonary function significantly worsened in the entire series, especially in the patients who developed DM.

CONCLUSIONS

(i) the natural history of glyco-metabolic status in CF is characterized by deteriorating GT over time; (ii) insulinopenia plays a prominent role in the pathogenesis of GT worsening; (iii) IR does not play any significant part in the pathogenesis of DM development; (iv) deterioration of lung function tests is more severe in the subjects who develop DM over time.

Liver glycogenosis as early manifestation in type 1 diabetes mellitus

Clinical symptoms and biochemical findings related to liver dysfunction are not generally reported among the presentation features of Type 1 diabetes mellitus (T1DM) in infancy and childhood. To our knowledge this is the first paper reporting two children with a clinical and biochemical picture of hepatic glycogenosis at the presentation of T1DM. In both cases at beginning of insulin therapy liver function and dimensions were absolutely normal, even though glycometabolic status had been severely altered for many days at T1DM onset. Both hepatomegaly and aminotransferase abnormalities were first found only some days after the institution of treatment with supraphysiological insulin doses. In both patients the improvement of glycometabolic control under insulin therapy was followed within some weeks by a complete physical and biochemical recovery, as typically reported in hepatic glycogenosis. These case reports demonstrate that hepatic glycogenosis can occur at any stage of T1DM and may even be one of its earliest manifestations, together with those classically reported at the onset of T1DM. Since long-standing hyperglycaemia and overinsulinisation are metabolic pre-requisites for hepatic glycogen storage, liver glycogenosis should be expected to be not uncommon during the first phases of T1DM, especially in the cases who are initially treated with supraphysiological insulin doses.

Stress, sexual dysfunctions, and male infertility

Involuntary childlessness is considered to be a chronic stressor for couples suffering from infertility. Stress itself may interfere with spermatogenesis and fertility rate. The long period of diagnostic and treatment procedures may also have a negative impact on the sex life of the infertile couple. In fact, we observed in such patients a higher frequency of male sexual disturbances expressed as erectile dysfunction, ejaculatory disorders, loss of libido and a decrease in the frequency of intercourse. We tried to partially overcome these sexual symptoms by administration of 50 mg of a type-V phosphodiesterase inhibitor (sildenafil) to two selected groups: patients collecting semen for artificial insemination and male partners of couples before post-coital testing. The results of this uncontrolled pilot study suggest that sildenafil is effective in increasing compliance of male patients facing infertile couple management procedures, and also in improving some sperm parameters, above all the number of sperm penetrating the cervical mucus.

Endocrinological diagnosis in sexology

Endocrine factors represent an important and potentially treatable cause of sexual dysfunction. The availability of a correct endocrinological diagnosis allows correct identification of most cases of sexual dysfunction in which the endocrine apparatus is involved. Not only the most frequent causes of endocrine sexual dysfunction, such as hypogonadism and hyperprolactinemia, but almost all extra-gonadal endocrinopathies (hyper- and hypothyroidism, hyper- and hypocortisolism, steroidal secreting tumors, etc.) may play a role to a greater or lesser extent in sexual function. It is therefore necessary that the diagnostic process for sexual dysfunctions of an endocrine nature be as integrated and wide as possible, especially as such pathologies are usually extremely responsive to medical or surgical therapy.

Risk assessment and prediction of rebleeding in bleeding gastroduodenal ulcer

BACKGROUND AND STUDY AIMS

The aims of this study were to identify risk factors for recurrence of hemorrhage in bleeding gastroduodenal ulcers after endoscopic injection therapy, and to develop a simple and relevant prognostic score which could be used to assess the early risk of recurrence and the residual risk of rebleeding.

PATIENTS AND METHODS

A prospective study was conducted from January 1995 to December 1998, in 738 patients who were admitted to our department for acute bleeding peptic ulcer and who underwent endoscopic examination. Ulcers with active bleeding or signs of recent bleeding were treated with injection therapy using epinephrine (1/10,000) and 1% polidocanol.

RESULTS

Multivariate analysis revealed that liver cirrhosis, recent surgery, systolic blood pressure below 100 mmHg, hematemesis, Forrest classification, and ulcer size and site were significantly predictive variables for the recurrence of hemorrhage. Among these, Forrest classification was the most important. The overall accuracy of the predictive model was 71% (95% CI = 63 - 79%). The model showed a better sensitivity of 90% for early rebleeding (< 48 hours) than for late rebleeding (> or = 48 hours) where the sensitivity was 65 %. A prognostic score was obtained and patients were classified into four risk classes: very low (VL), low (L), high (H), and very high (VH). The rebleeding rates for the four classes were 0%, 7.9%, 31.8% and 67.9%, and the mortality rates were 5.9%, 8.6%, 13.9% and 35.7%, respectively. The residual risk of rebleeding after 48 hours was 0%, 3.3%, 10.4%, and 14.3% in the VL, L, H and VH classes, respectively. After 5 days the residual risk was under 4% in all classes.

CONCLUSIONS

This study demonstrates that the proposed prognostic score, which is easily obtained after emergency endoscopy, is useful in clinical practice because it can identify patients with different levels of rebleeding risk. It can be helpful in patient management and decision making for discharge.

Two-year prospective evaluation of the factors affecting honeymoon frequency and duration in children with insulin dependent diabetes mellitus: the key-role of age at diagnosis

The aim of this study was to investigate the influence of pre-treatment variables on subsequent insulin requirement (IR) and partial remission (PR) in children with insulin-dependent diabetes mellitus (T1DM). Sixty-seven children with newly diagnosed T1DM, admitted to our Clinic during a 3-year recruitment period, were longitudinally evaluated for 2 yr. Patients were characterized by sex, age, parental education, duration of symptomatic history at diagnosis, admission duration, ketoacidosis or absence of ketoacidosis and residual beta-cell activity. More than 80% of the children experienced a PR, which lasted more than 12 months in 41.7% and at least 24 months in 16.4% of cases. The prevalence of PR at different ages after T1DM onset was significantly lower in children diagnosed while younger than 5 years than in those diagnosed after 5 years. The mean duration of the remission period was 11.7 +/- 8.9 months, irrespectively of sex, duration of the symptomatic period preceding T1DM diagnosis, parental education, blood pH and base excess, HbA1c concentration and admission duration. Beta-cell residual function evaluated after glucagons stimulation test (basal and 6 min C-peptide) was statistically different in PR patients and in those who experienced no remission. Age at diagnosis was the only pre-treatment factor which, on stepwise regression analysis, affected both PR duration and IR at the end of follow-up. To conclude, honeymoon frequency and duration are strictly conditioned by both residual beta-cell function and IR at T1DM onset. Since IR is higher in younger subjects, early onset of T1DM can be considered the factor with the most detrimental influence on honeymoon incidence. Other pre-treatment variables have no significant impact on PR.

[Acute hemorrhage caused by duodenal ulcer. Results of endoscopic treatment of the first bleeding episode and of recurrences]

BACKGROUND

The aim of this study was to evaluate the impact of immediate endoscopic treatment of bleeding and rebleeding on the clinical outcome of patients with duodenal ulcer hemorrhage.

MATERIALS AND METHODS

Between January 1995 and December 1998, 445 patients with bleeding duodenal ulcers were observed in the First Division of General Surgery--University of Verona. All patients, except two who died for hemorrhage before the endoscopic examination, underwent emergency endoscopy within 2 hours from the admission and ulcers with active or sign of recent bleeding were submitted to injection therapy. History, clinical and endoscopic findings, recurrent bleeding and outcome were prospectively collected and analyzed. Recurrent bleeding underwent immediate endoscopic retreatment as first attempt.

RESULTS

Endoscopic therapy was performed in 277 patients with active bleeding and hemostasis was initially obtained in all patients except one. Rebleeding occurred in 62 patients (14%) and endoscopic treatment was successful in 85% of first rebleeding and in 58% of the cases with 2 or more rebleeding. Multivariate analysis showed that systolic blood pressure at admission, ulcer size and Forrest classification influenced independently the recurrence rate. The 30 days mortality was 12.2% in the whole series: 35 deaths (9.2%) in the group without recurrence and 19 (30.6%) deaths in the rebleeding group (p = 0.001). Only 22 patients (5%) underwent surgical treatment with a higher mortality compared to not operated patients (36.4% versus 10.9%).

CONCLUSIONS

Endoscopic treatment was associated with reductions of the risk of recurrent bleeding and surgery without increasing mortality rate.

Endoscopic treatment of esophageal granular cell tumors

There are no standard guidelines for the treatment of granular cell tumor (GCT). The aim of our study was to describe three cases of esophageal GCT and, on the basis of our experience, analyze the indications for and results of their endoscopic treatment. When deciding whether to proceed with surgical or endoscopic resection, endosonography plays a key role in establishing whether the tumor is confined to the submucosa. All three cases were confined within the hyperechoic layer of the submucosa and were successfully treated by endoscopic excision without complications or signs of relapse during the follow-up period.

[Peptic ulcer hemorrhage in the elderly]

BACKGROUND

The aim of this study was to investigate the efficacy of endoscopic injection therapy on the clinical outcome of elderly patients with peptic ulcer bleeding.

METHODS

From January 1995 to December 1998, 738 patients with acute peptic ulcer bleeding were observed in the First Division of General Surgery, University of Verona: 359 aged <70 years and 379 =/>70 years. History, clinical and endoscopic findings and outcome were prospectively collected and analyzed comparing old (=/>70 yrs) and young (<70 yrs) patients. Ulcers with active or sign of recent bleeding were submitted to injection therapy using epinephrine and 1% polidocanol.

RESULTS

Coexisting diseases were significantly more present in the elderly group except for liver cirrhosis that affected preferentially young patients (12.3 versus 4.0%; p<0.001). Endoscopic treatment was performed in a similar percentage between young and elderly patients (respectively 64.9 e 61.5%) and also the rebleeding rate (14.2 versus 13.2) and the mean duration of hospitalisation were not different. The overall mortality was 12.7% in the elderly group and 8.3% in the young group (p=0.04), whereas mortality after surgery was significantly higher in the young group (respectively 57.1 versus 8.3%; p=0.037).

CONCLUSIONS

The clinical and endoscopic features and reebleeding rate were not different between elderly and young patients. Patients aged 70 years or older have a higher number of associated medical diseases except for liver cirrhosis conditions and a highest overall mortality whereas the risk of death after surgery is lower than in the younger group.