Clinical outcomes in elderly patients with infections caused by NDM-producing Klebsiella pneumoniae: results from a real-life retrospective single center study in an endemic area

Real-life outcomes data for elderly patients with infections caused by Klebsiella pneumoniae producing New Delhi metallo-beta-lactamase (NDM-Kp) are lacking. We conducted a retrospective cohort study enrolling 33 consecutive adult patients (mean age 77.4 years; 48.5% males; mean Charlson Comorbidity Index-CCI 5.9) hospitalized for NDM-Kp infections during a 24-month period in an Italian highly endemic area. 78.8% were admitted to Internal Medicine ward. 45.4% of patients had bloodstream infections (BSI), 39.4% urinary tract infections (UTI) without BSI, 9.1% respiratory tract infections and 6.1% intra-abdominal infections. 93.9% had rectal colonization.Adequate definitive antibiotic therapy (mainly represented by aztreonam plus ceftazidime/avibactam) was provided to 36.4% of cases. Mean age and CCI of patients adequately treated were significantly lower than those inadequately treated (71.2 vs 80.9 years, p = 0.041, and 4.6 vs 6.7, p = 0.040, respectively). Patients adequately treated had a mean hospitalization length significantly higher (28 vs 15 days, p = 0.016). The overall 30-day survival rate of patients adequately and inadequately treated was 83.3% and 57.1%, respectively: this difference was not statistically significant. Mean age and CCI of 22 patients who survived at 30 days were lower than those of 11 patients who died (73.7 vs 84.8 years, p = 0.003, and 5.3 vs 7.2, p = 0.049, respectively). Twelve survivors received an inadequate therapy: 8/12 had UTI. Six of nine patients inadequately treated who died within 30 days, died before microbiological diagnosis. Our study provides real-life data on outcomes of elderly and multimorbid patients hospitalized for infections caused by NDM-Kp. Further studies with larger sample size are warranted.

A Severe Necrotizing Inflammatory Reaction of Leg Wounds Following Autologous Peripheral Blood Total Nucleated Cells Treatment in an Old Patient With Rheumatoid Arthritis and No-Option Chronic Limb-Threatening Ischemia: Is Cell Therapy Suitable for All Patients?

Chronic limb-threatening ischemia (CLTI) represents an unfavorable evolution of peripheral artery disease, characterized by pain at rest, ulceration, and gangrene and also by an increased risk of cardiovascular events, amputations, and death. According to scientific literature, in almost one third of cases affected by CLTI, defined as no-option CLTI patients, revascularization strategies are not feasible. In the past decade, several studies investigated the role of therapeutic angiogenesis through cell autologous therapy, administered through intramuscular injections or multiple local intralesional and perilesional injections. In this article, we report the case of a necrotizing inflammatory reaction in a patient affected by CLTI and chronic leg wounds that occurred on the multiple injection sites after autologous peripheral blood-derived mononuclear cells (PB-TNCs) transplantation. Since the patient was affected by corticosteroid-induced skin atrophy and rheumatoid arthritis, we hypothesize that an increased skin fragility and a mechanism of immune-mediated pathergy could have been main factors leading to worsening of wounds. This case report strongly suggests the urgent need to better define the indications and contraindications of cell therapy, and further studies of adequate methodology are required to definitively assess the efficacy and safety of autologous cell therapy by local injections of PB-TNCs in patients with chronic inflammatory disorder, such as rheumatoid arthritis, especially in case of concomitant marked skin atrophy. Pending definitive evidence from literature, a strong caution is needed in patients affected by chronic systemic inflammatory diseases, since multiple injections, acting as mechanical stimulus and pathergy trigger, might exacerbate a severe and uncontrolled inflammatory response.

Transcranial ultrasonography imaging of a suprasellar meningioma: A case description and technical notes

Background

Computed tomography (CT) and magnetic resonance (MR) represent the gold standard for evaluating intracranial tumours, such as meningiomas; most meningiomas can be managed by surveillance and clinical follow-up, therefore, the ideal technology should be cheap, non-invasive, safe and able to reduce radiation exposure. Transcranial colour-coded duplex sonography (TCCS) can detect space-occupying lesions, but its full potential for clinical practice is still unexpressed.

Aims and Methods

We describe the ability of TCCS to directly and accurately image, in a 77-year-old woman hospitalised for septic shock and coma, a suprasellar meningioma with a spatial resolution very similar to CT.

Results

The meningioma was clearly visualised as a roundish mass, with well-defined borders, heterogeneously hyperechogenic compared with the surrounding brain structures; multiple intralesional calcifications were detectable as highly echogenic spots. Latero-lateral and antero-posterior diameters were well measurable.

Discussion

TCCS should not be considered as an alternative to CT and MR imaging, but it might have a complementary role, useful for use at the bedside in uncooperative or non-transportable patients and for follow-up, when an adequate acoustic window is guaranteed. Neurologists and neuroradiologists should further explore the full potential of this technology.

Detection of a pituitary macroadenoma with transcranial ultrasonography: Principles and potential clinical applications

Transcranial color-coded duplex sonography (TCCS) allows to study intracranial vessels through the intact skull, but the visualization of normal and pathologic brain structures in adults is often suboptimal due to inadequate acoustic window. The full potential of TCCS for clinical practice remains unfulfilled. Here, we describe the ability of TCCS to detect a non-functioning pituitary macroadenoma in a 58-year-old man affected by headache. The macroadenoma was visualized as a roundish, well-defined mass, mildly hyperechogenic compared to the hypoechogenic mesencephalic brainstem but mainly hypoechogenic compared to the surrounding intracranial structures. Intracranial vessels represented useful landmarks. Using tissue harmonic imaging mode, the borders of the macroadenoma were visualized more clearly. Macroadenoma characteristics were confirmed by magnetic resonance imaging. Neurosonologists should be aware of the possibility to incidentally find, during routinary TCCS, pituitary macroadenomas or other brain tumors (as incidentalomas), worthy to be recognized and referred for further investigations.

Skin Ulcers are Predictors of 30-Day Hospital Readmission, But are Under-represented in the DRG Coding: A Retrospective Case-Control Study From an Italian Internal Medicine Unit

This study retrospectively analyzes all consecutive patients who underwent during a year hospital readmissions, defined as an admission to a hospital within 30 days of discharge, to an Italian Internal Medicine ward. All these data were compared with those from patients who underwent only 1 hospital admission in the same period. The aim of this study was to identify potential novel risk factors for hospital readmissions. In 2018, a total of 3012 patients were hospitalized. Among these, 14.1% (n = 426; mean age, 79.7 ± 11.9; range, 23-100) were defined as readmissions; data were compared with controls (n = 420; 13.9%; mean age, 75.9 ± 14.7; range, 22-99) who had only 1 hospitalization. Cases showed a significantly higher prevalence than controls regarding cerebrovascular disease (77.2% vs 48.1%), cognitive impairment (51.8% vs 26.9%), congestive heart failure (47.6% vs 20.2%), chronic kidney disease (31.7% vs 13.1%), and chronic obstructive pulmonary disease (23.0% vs 14.5%). Skin ulcers were significantly more prevalent among cases (45.1% vs 17.6%). Diagnosis-related group (DRG) analysis showed a higher proportion of "infectious disease" (24.4% vs 15.0%) among the cases than in controls. Despite skin ulcers were very frequent among cases and controls (45.1% vs 17.6%), they were codified as "skin wound" DRG only in 1.4% and 0.2%, respectively. At the DRGs analysis, sepsis (31.6% vs 19.1%), pneumonia (17.1% vs 7.6%), and kidney failure (9.6% vs 3.8%) represented the main significant cause of death in cases compared to controls. Our study confirms that readmissions to Internal Medicine departments are related to the severity of chronic diseases affecting patients. Skin ulcers are present in about half of patients who will be early readmitted within 30 days, but they are almost never reported in DRGs, so more accurate coding is needed. Key challenges for the future are sepsis prevention measures and investing resources in chronic disease assistance, including skin ulcer chronic management.

Reinfection of SARS-CoV-2 - analysis of 23 cases from the literature

INTRODUCTION

The duration of immunity after infection from SARS-CoV-2 conferring protection from subsequent COVID-19 episodes is not yet fully understood. We reviewed the literature for cases of documented reinfection.

MATERIALS AND METHODS

A comprehensive computerized search in PubMed, through 15 December 2020, using the following terms in combination: COVID-19, SARS-CoV-2, reinfection, reactivation, recurrence. To exclude cases due to prolonged viral shedding or protracted infection, only cases occurring at least 12 weeks apart or confirmed as being sustained by genetically different viruses by viral genome analysis were included.

RESULTS

We identified 23 cases globally, for which viral genome analysis was performed in 10 cases and serology in 19 cases. The mean interval between the two episodes was 15 weeks. Mean age of cases was 44.5 years, and 10 (43.5%) were women. In 17/23 cases, no comorbidity was observed. In 10 cases, the first episode was more severe than the ensuing episode, whereas in seven cases the ensuing episode was more severe. In four cases, there was no difference in severity and in two cases both episodes were asymptomatic.

CONCLUSIONS

From this sample of 23 cases, a clear pattern of the second episode being less or more severe did not emerge. A better understanding of immunity to SARS-CoV-2, necessary to assess the probability of a second infection and the durability of protection conferred by vaccination, is warranted.

D-Dimer as Biomarker for Early Prediction of Clinical Outcomes in Patients With Severe Invasive Infections Due to Streptococcus Pneumoniae and Neisseria Meningitidis

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection; no current clinical measure adequately reflects the concept of dysregulated response. Coagulation plays a pivotal role in the normal response to pathogens (immunothrombosis), thus the evolution toward sepsis-induced coagulopathy could be individuate through coagulation/fibrinolysis-related biomarkers. We focused on the role of D-dimer assessed within 24 h after admission in predicting clinical outcomes in a cohort of 270 patients hospitalized in a 79 months period for meningitis and/or bloodstream infections due to Streptococcus pneumoniae (n = 162) or Neisseria meningitidis (n = 108). Comparisons were performed with unpaired t-test, Mann-Whitney-test or chi-squared-test with continuity correction, as appropriate, and multivariable logistic regression analysis was performed with Bayesian model averaging. In-hospital mortality was 14.8% for the overall population, significantly higher in S. pneumoniae than in N. meningitidis patients: 19.1 vs. 8.3%, respectively (p = 0.014). At univariable logistic regression analysis the following variables were significantly associated with in-hospital mortality: pneumococcal etiology, female sex, age, ICU admission, SOFA score, septic shock, MODS, and D-dimer levels. At multivariable analysis D-dimer showed an effect only in N. meningitidis subgroup: as 500 ng/mL of D-dimer increased, the probability of unfavorable outcome increased on average by 4%. Median D-dimer was significantly higher in N. meningitidis than in S. pneumoniae patients (1,314 vs. 1,055 ng/mL, p = 0.009). For N. meningitidis in-hospital mortality was 0% for D-dimer <500 ng/mL, very low (3.5%) for D-dimer <7,000 ng/mL, and increased to 26.1% for D-dimer >7,000 ng/mL. Kaplan-Meier analysis of in-hospital mortality showed for N. meningitidis infections a statistically significant difference for D-dimer >7,000 ng/mL compared to values <500 ng/mL (p = 0.021) and 500-3,000 ng/mL (p = 0.002). For S. pneumoniae the mortality risk resulted always high, over 10%, irrespective by D-dimer values. In conclusion, D-dimer is rapid to be obtained, at low cost and available everywhere, and can help stratify the risk of in-hospital mortality and complications in patients with invasive infections due to N. meningitidis: D-dimer <500 ng/mL excludes any further complications, and a cut-off of 7,000 ng/mL seems able to predict a significantly increased mortality risk from much <10% to over 25%.

The Paradox of the Low Prevalence of Current Smokers Among COVID-19 Patients Hospitalized in Nonintensive Care Wards: Results From an Italian Multicenter Case-Control Study

Introduction

COVID-19, a respiratory illness due to SARS-CoV-2 coronavirus, was first described in December 2019 in Wuhan, rapidly evolving into a pandemic. Smoking increases the risk of respiratory infections; thus, cessation represents a huge opportunity for public health. However, there is scarce evidence about if and how smoking affects the risk of SARS-CoV-2 infection.

Methods

We performed an observational case-control study, assessing the single-day point prevalence of smoking among 218 COVID-19 adult patients hospitalized in 7 Italian non-intensive care wards and in a control group of 243 patients admitted for other conditions to 7 general wards COVID-19-free. We compared proportions for categorical variables by using the χ2 test and performed univariate and multivariate logistic regression analyses to identify the variables associated with risk of hospitalization for COVID-19.

Results

The percentages of current smokers (4.1% vs 16%, p=0.00003) and never smokers (71.6% vs 56.8%, p=0.0014) were significantly different between COVID-19 and non-COVID 19 patients. COVID-19 patients had lower mean age (69.5 vs 74.2 years, p=0.00085) and were more frequently males (59.2% vs 44%, p=0.0011). In the logistic regression analysis, current smokers were significantly less likely to be hospitalized for COVID-19 compared with non-smokers (Odds ratio 0.23; 95% CI, 0.11-0.48, p<0.001), even after adjusting for age and gender (OR 0.14; 95% CI, 0.06-0.31, p<0.001).

Conclusions

We reported an unexpectedly low prevalence of current smokers among COVID-19 patients hospitalized in non-intensive care wards. The meaning of these preliminary findings, which are in line with those currently emerging in literature, is unclear; they need to be confirmed by larger studies.

Implications

An unexpectedly low prevalence of current smokers among patients hospitalized for COVID-19 in some Italian non-intensive care wards is reported. This finding could be a stimulus for the generation of novel hypotheses on individual predisposition and possible strategies for reducing the risk of infection from SARS-CoV-2, and needs to be confirmed by further larger studies designed with adequate methodology.

Concentrations of chlorinated pollutants in adipose tissue of yellow-legged gulls (Larus michahellis) from Spain: Role of gender and age

Concentrations of 7 different polychlorinated biphenyl (PCB) congeners, and eleven organochlorine pesticides (OCPs) and metabolites, including DDTs (dichlorodiphenyltrichloroethane), HCHs (hexachlorocyclohexane isomers), Endosulfan, Endosulfan sulfate, Endrin, Dieldrin and HCB (hexachlorobenzene), were determined in adipose tissue of 57 yellow-legged gulls collected from NW and N Spain. Furthermore, the possible differences due to two endogenous factors, age and gender, were determined. All the analyzed PCBs were detected in over 66% of the samples, with levels of 291.9 (PCB 180), 34.5 (PCB 118), 0.7 (PCB 28), 432.6 (PCB 153), 225.5 (PCB 138), 1.3 (PCB 101) and 0.4 (PCB 52) µg/kg of adipose tissue. With respect to the OCPs and metabolites, only 4,4'-DDE and HCB were detected in more than 50% of the samples, with means of 360.6 and 2.5 µg/kg of adipose tissue, respectively. From all the considered contaminants, only 4,4'-DDE levels presented significant differences depending on the gender, with females showing higher values than males (p < 0.01). Significant differences (p < 0.001) were also found related to age for the levels of PCBs 180, 138, 101, 28 and 153, as well as 4,4'-DDE, with adult levels being higher than those in young birds. The results of the present study constitute a baseline to better assess the environmental impacts of PCB and OCP contamination at other coastal sites for future biomonitoring studies, with particular emphasis on gender- and age-related differences.

Halogenated flame retardants in stranded sperm whales (Physeter macrocephalus) from the Mediterranean Sea

In recent years, decline of marine mammals' populations and increased frequency of strandings have arised the interest on the role that pollution may have in these events. The present work aimed at quantifying levels of brominated flame retardants (BFRs) and dechloranes (DECs) in tissues of 3 adult females and one foetus of sperm whales stranded in the Southern Adriatic Sea coasts (Italy). Results proved the presence of different flame retardants (FRs) in tissues of sperm whales, including various polybrominated diphenyl ethers (PBDE) congeners (47, 99, 100, 154, entering the composition of PentaBDE mixture), hexabromocyclodecanes (HBCDs), Dec 602 and methoxylated polibrominated diphenyl ethers (MeO-BDEs). In blubber, a target tissue for contaminant accumulation, ΣPBDEs reached values of 160, 158 and 183 ng/g lw, α-HBCD of 5.75 ng/g lw, Dec 602 of 1632 ng/g lw and MeO-BDEs of 563 ng/g lw. The availability of foetal tissues allowed evaluating the potential maternal transfer on many of these compounds, and to discuss the potential adverse effects on foetal health. To the best of our knowledge, obtained data are the first reporting placental transfer of FRs in sperm whales. PBDE levels detected in foetus suggested a potentially long-term exposure to BFRs, which could cause severe damages to the developing organism, likely at the cerebral, endocrine and immunologic levels. Dec 602, which was detected at the highest concentrations among all FRs considered, could potentially cause dysfunctional effects on the immune system of adult females.

Pyoderma Gangrenosum: A Current Problem as Much as an Unknown One

Pyoderma gangrenosum (PG) is a rare neutrophilic inflammatory skin disease, characterized by recurrent skin ulcers, which in almost 50% of cases are associated with systemic autoimmune disorders, including rheumatoid arthritis, chronic hepatitis, inflammatory bowel disease, paraproteinemias and hematological malignancies. A systematic search of literature for PG was carried out using the PubMed, Embase, and Google Scholar databases for the purpose of this review and 2780 articles were retrieved up to February 2017. Inflammation represents the predominant aspect of the disease, but its pathophysiological mechanisms are not completely clear yet, since there are many studies showing only one or more isolated findings of the disease. The goal of PG treatment is to reduce inflammation in order to promote ulcer healing by minimizing side effects of therapy. Several systemic and local treatments are available, but the lack of large randomized double-blind studies results in an absence of a uniform therapeutic standard: thus, more clinical studies are required in order to make head-to-head comparisons between combination and single-drug therapies and to identify specific combination therapies for distinctive clinical patterns of PG.

Recurrence of Graves' disease in thyroglossal duct remnants: relapse after total thyroidectomy

BACKGROUND

Ectopic thyroid tissue can be found anywhere between the foramen cecum and the normal position of the thyroid gland, most commonly located in the anterior cervical area, the region of the thyroglossal duct. Although thyroid cancer has been described frequently in thyroglossal duct remnants, thyroid dysfunction related to this tissue is rare. We report a patient with recurrent Graves' disease arising in a thyroglossal duct remnant.

SUMMARY

A 40-year-old woman with a history of total thyroidectomy for Graves' disease, presented with a slowly enlarging midline neck mass in association with clinical signs of hyperthyroidism. Serum-free triiodothyronine (6.6 pg/mL) and serum-free thyroxine (2.2 ng/dL) were elevated (normal range, 2.3-4.2 pg/mL and 0.9-1.8 ng/dL, respectively), and thyroid-stimulating hormone was suppressed (<0.01 mIU/mL; normal range, 0.35-5.50 mIU/mL). Neck ultrasonography showed a solid mass, localized at the infrahyoid area; radionuclide scanning confirmed an increased uptake at the same level. A 4 cm solid mass was removed by the Sistrunk technique. Microscopic examination revealed marked follicular hyperplasia, with tall cells, small follicles, scant, and scalloped colloid, in association with patchy lymphocytic infiltrate consistent with Graves' disease.

CONCLUSIONS

There appears to be no reason why thyroid cells within thyroglossal duct remnants should not be influenced by the thyroid-stimulating immunoglobulins of Graves' disease. Thyrotoxicosis resulting from this must be very rare, however, as were unable to find reports of patients with thyrotoxicosis due to Graves' disease in thyroglossal duct remnants. Although some thyroid tissue can be found within the thyroglossal duct in 1.6% to 40% of normal adults, the risk of thyroid dysfunction from this is far too low to justify new therapeutic approaches.

[Laparoscopic approach in acute appendicitis: experience with 501 consecutive cases]

Appendicitis is an acute disease requiring urgent surgical treatment. Acute appendicitis is the most common surgical emergency in children and young adults, with an incidence of about 100-140 cases per 100,000 people. In our study we analyse 501 consecutive appendectomies performed in our department. From June 2003 to December 2008 we performed 501 appendectomies, 287 in male and 214 in female patients. The average age was 27.99 years (range: from 4 to 94 years). We routinely perform a laparoscopic approach with a standard protocol for patient selection. Following a standard protocol, 429 patients were selected for the laparoscopic approach and 72 for an open appendectomy. In 411 patients (95.8%) the surgical procedure was completed in laparoscopy with a conversion rate of about 4.2% (18/429). The conversion rate in the simple appendectomy subgroup was 0.98%, as against about 12.1% in the complex appendectomy subgroup. The open appendectomy group comprised 72 patients, 27 patients treated with an open approach by choice, 26 for necessity and 19 for protocol violation. There were 9 post-appendectomy complications (2.1%) and 3 re-operations (0.5%); the mortality rate was nil. Although 20 years have passed since the first laparoscopic appendectomy, today it is still debated whether or not the laparoscopic approach is the correct surgical procedure for the treatment of acute appendicitis. Several studies have shown that laparoscopic appendectomy presents a number of advantages in terms of a shorter hospital stay, less postoperative pain and fewer wound infections. Some authors, however, have demonstrated that the laparoscopic approach for acute appendicitis is associated with increased operative times and risk of intra-abdominal abscesses (above all if the appendix is perforated). Our experience confirms that the routinely performed laparoscopic approach to treat acute appendicitis is associated with a low rate of abscess complications: in our series some of the complications could be attributed to the surgical learning curve.

Vascular involvement in diabetic subjects with ischemic foot ulcer: a new morphologic categorization of disease severity

OBJECTIVES

Arteriographic lesions of diabetic subjects with critical limb ischemia (CLI) and ischemic foot ulcer were reviewed retrospectively, to provide new criteria for stratification of these patients on the basis of their vascular involvement.

PATIENTS

In 417 consecutive CLI diabetic subjects with ischemic foot ulcer undergoing lower limb angiography, lesions were defined as stenosis or occlusion, localization, and length (<5 cm, 5-10 cm, >10 cm). In a subgroup of 389 subjects, foot arteries also were evaluated. Patients then were categorized into 7 classes of progressive vascular involvement based on angiographic findings.

RESULTS

Of the 2893 found lesions (55% occlusions) 1% were in the iliac arteries, whereas 74% were in below-the-knee (BTK) arteries. Sixty-six % of all BTK lesions were occlusions, and 50% were occlusions >10 cm (p<0.001 vs proximal segments). Occlusions of all BTK were present in 28% of patients, although there was patency of at least one foot artery in 55% of patients. The morphologic Class 4 (two arteries occluded and multiple stenoses of tibial/peroneal and/or femoral/popliteal vessels) was the most common (36%). An inverse correlation between morphologic class and TcPO2 was observed (r=-0.187, p=0.003).

CONCLUSIONS

In CLI diabetic subjects with ischemic foot ulcer, the vascular involvement is extremely diffuse and particularly severe in tibial arteries, with high prevalence of long occlusions. A new morphologic categorization of these patients is proposed.

[Headache caused by analgesic and/or ergotamine abuse]

Headache induced by ergotamine-abuse was described 40 years ago. More recently there is ample evidence suggesting that chronic headache may also be provoked by analgesic abuse. A recent Classification of the International Headache Society has defined this kind of headache as an autonomous disease. It consists in a daily chronic headache with paroxysmal attacks associated with daily or almost daily assumption of analgesics and/or ergotamine. It is debated whether the term "abuse" or "dependence" is correct. Almost 5% of patients of the Headache Centres in Italy were found to be drug abusers. Most of these patients originally suffered from migraine. The therapeutic approach consists in hospitalization, withdrawal of analgesics and/or ergotamine, treatment of the withdrawal headache (which appears within 48 hours and lasts even 1-2 weeks) and finally in a prophylactic therapy. Although several treatments have been suggested for the abstinence syndrome, only fluid replacement, antiemetics, hypnotic-sedative drugs and rarely mild analgesics are necessary. A review of the literature shows the following success rates in the relief of the headache: above 50% relief in more than 60% of patients within a follow up period of 1 to 3.5 years as mean. Even if caffeine and barbiturates, which are often contained in the analgesic and ergotamine preparations, might be considered the cause of the abuse and withdrawal syndrome, they don't seem to play a fundamental role in this syndrome. An impairment of the central antinociceptive system was hypothesized to be involved in the pathogenesis of the headache associated with analgesic and/or ergotamine abuse. Recently there has been evidence of a possible hyposensitivity of the adrenergic and serotoninergic receptors of the central nervous system. It is still to be proved whether drug abuse is the cause or the consequence of the headache chronicization. The remarkable improvement of headache after analgesic withdrawal suggests a causal factor.

Reduced serotonin vascular sensitivity in ergotamine abusers

The action of ergotamine on the 5-hydroxytryptamine (5-HT) venous sensitivity was studied in ergotamine abuser and non-abuser migraine patients. Ergotamine abusers showed reduced 5-HT hand vein contraction during abuse, compared to seven days after ergotamine withdrawal. In non-ergotamine users, the 5-HT venoconstriction was not significantly modified 12 h after a single intramuscular ergotamine (0.25 mg) administration. Even the administration of ergotamine locally into the vein did not change the venospasm of 5-HT given acutely in the same vein. Therefore, it seems that the 5-HT antagonism does not contribute to the therapeutic effect of ergotamine during the migraine attack. Moreover, the reduced 5-HT responsiveness during ergotamine abuse may possibly be compatible with the chronic headache present in some abusers, the withdrawal headache attacks and the abuse itself.

Effects of calcium antagonists on serotonin and noradrenaline venoconstriction in humans

The activity of some calcium antagonists on 5-hydroxytryptamine (5HT) and noradrenaline-induced venoconstriction has been evaluated in humans. Oral doses of nimodipine, 30 mg, and nifedipine, 10 mg, but not of verapamil, 80 mg, and flunarizine, 10 mg, inhibit 5HT-induced venoconstriction of the dorsal hand vein. Nimodipine, but not verapamil and flunarizine, inhibit noradrenaline-induced venoconstriction as well. Verapamil, locally administered into the hand vein, inhibits 5HT and noradrenaline-induced venoconstriction. These results suggest that only calcium antagonists of the dihydropyridine type have antivenoconstrictive activity in the hand vein at oral clinical doses, whereas verapamil is active only if administered by the intravenous route, which probably produces local plasma concentrations higher than those reached with the oral clinical doses.

Somatostatin: peripheral venoconstrictive activity and interaction with monoamines in man

The mechanism of somatostatin venoconstriction and tachyphylaxis in the human hand vein in vivo has been investigated. No cross-tachyphylaxis was observed between somatostatin and 5-hydroxytryptamine, noradrenaline, adrenaline, dopamine or tyramine-induced venoconstriction. Somatostatin potentiates the venoconstrictive activity of noradrenaline, adrenaline and dopamine, but not that of 5-hydroxytryptamine and tyramine. Phentolamine antagonizes the somatostatin-induced venoconstriction, whereas methysergide, haloperidol and morphine do not. It is suggested that somatostatin could act on specific receptors in the hand vein, but the mechanism of somatostatin venoconstriction and interaction with vasoactive monoamines remains to be defined.