Effects of thyroid hormones on liver binding sites for human growth hormone, as studied in the rat.

Several weeks after thyroidectomy (T), female rats stopped growing, and their pituitary GH content had decreased to less than 2--3% of the values found for age-matched controls (C). The liver membranes of such animals were explored with human GH (hGH). It was found that in the severely hypothyroid T rat, the number, but not the affinity, of the lactogenic binding sites was markedly reduced. Treatment of these rats for 3 weeks with 1.75 micrograms or T4 or 0.5 micrograms T3/100 g body weight/day restored growth, increased pituitary GH content and restored the number of liver lactogenic binding sites were practically to normal. As regards the lactogenic binding sites, similar results were obtained when the severely hypothyroid rats were treated with a much lower T4 dose (0.2 microgram/100 g/day): this dose was clearly growth promoting, and restored to normal both the low circulating GH levels and the pituitary PRL content of the severely hypothyroid rat. The changes in plasma PRL were not clear. The lactogenic binding sites on liver membranes from rats which were both thyroidectomized and hypophysectomized were decreased in number. Treatment with 0.5 microgram T3/100 g/day for 30 days (but not for 12 days) resulted in an increase in the number of lactogenic binding sites, though it did not affect growth or the undetectable plasma GH levels. The effect on the lactogenic binding sites was less marked than in T rats with an intact pituitary. It would appear that minute amounts of thyroid hormones are needed for maintenance of liver lactogenic binding sites; it is possible that this not only occurs through mechanism(s) which involve the pituitary, but also through others which do not. The possible role of these receptors in growth processes is not yet clearly understood.     

Thiocyanate induces cell necrosis and fibrosis in selenium- and iodine-deficient rat thyroids: a potential experimental model for myxedematous endemic cretinism in central Africa

Thyroid destruction leading to endemic myxoedematous cretinism is highly prevalent in central Africa, where iodine (I) and selenium (SE) deficiencies as well as thiocyanate (SCN) overload are combined. All three factors have been studied experimentally in the etiology of the disease, but they have never been studied in combination. In a model using rats, we have previously shown that combining I and SE deficiencies increases the sensitivity of the thyroid to necrosis after iodide overload, an event unlikely to occur in the African situation. To develop a model that would more closely fit with the epidemiological findings, we have determined whether an SCN overload would also result in thyroid necrosis as does the I overload. The combination of the three factors increased by 3.5 times the amount of necrotic cells, from 5.5 +/- 0.3% in the I-SE+ thyroids to 18.9 +/- 1.6% in the I-SE-SCN-overloaded ones. Methimazole administration prevented the SCN-induced necrosis. SE- thyroids evolved to fibrosis, whereas SE+ thyroids did not. TGFbeta was prominent in macrophages present in SE- glands. Thyroid destruction in central Africa might therefore originate from the interaction of three factors: I and SE deficiencies by increasing H(2)O(2) accumulation, SE deficiency by decreasing cell defense and promoting fibrosis, and SCN overload by triggering follicular cell necrosis.     

Recommendations from GESIDA/SEFH/PNS to improve adherence to antiviral treatment (2004)

Since the early days of antiretroviral therapy, adherence has emerged as the milestone of success; in fact, it is the most potent predictor of effectiveness. The main factors related to adherence include the complexity of the therapeutic regimen, adverse effects, psychological problems, alcoholism and active addiction to drugs, lack of social and family support and the patient's beliefs and attitudes about the treatment. Adherence monitoring should be part of the HIV patient's regular care, and should be done with feasible, easily applied methods adapted to the different clinical settings. The minimally acceptable measures should include use of a validated questionnaire, together with data from the Pharmacy Department's drug dispensation registry. All patients that begin HAART or undergo a change of treatment should participate in a treatment education program imparted by health professionals with knowledge and experience in the management of patients with HIV infection. The health team (doctors, pharmacists and nursing professionals) should offer maximum availability to solve the doubts and problems that may occur during treatment. When sub-optimal adherence is detected, intervention strategies based on psychological therapy, educational efforts and personal advice should be attempted, in order to adapt the treatment scheme to the patient's habits and provide solutions to the problem of non-compliance. In certain situations, co-morbid conditions will also require attention. Treatment adherence, being a multidimensional problem, needs a multidisciplinary team approach. The choice of therapy, only one aspect of the multidimensional problem of adherence, must be a careful and individualized decision; however, simpler regimens with regard to the number of pills and daily dose are desirable.     

Valvuloplasty with balloon catheter in biologic prosthesis. Reality or illusion

We performed catheter balloon valvuloplasty (CBV) on 8 stenotic operatively-excised bioprosthetic valves (2 Hancock and 6 Ionescu Shiley). Pathology of valves before CBV included degenerative changes: commissural fusion by mounds of calcific deposits (2 valves), fibrotic and focally calcified leaflets (7 valves) and stiff and thick valves (1 valve). Inflation of the balloon resulted in commissural splitting (2 valves), leaflet cracks and fractures (3 valves). Removal of the deflated balloon catheter was associated with debris dislodgement (3 valves). In one case the valve was unable to close with potential for acute regurgitation. Thus, CBV of bioprosthetic valves can split fused commissures by similar mechanisms as in native valves. CBV may fracture calcific deposits causing acute emboli. It can also disrupt the leaflets causing acute insufficiency. The findings suggest a limited role of CBV in the treatment of stenotic bioprosthetic valves in mitral and aortic position.     

Apical Hypertrophic Cardiomyopathy: Preliminary Attempt at Palliation with Use of Subselective Alcohol Ablation

We report a case of severe apical hypertrophic cardiomyopathy in order to discuss the nature of this unusual condition and the possibility of using selective alcohol ablation to effectively treat symptomatic hypertrophic cardiomyopathy that presents with apical aneurysm. A 73-year-old woman with severe, progressive dyspnea and intermittent chest pain was found to have localized left ventricular apical dyskinesia distal to an obstructive mid-distal muscular ring. The ring caused total systolic obliteration of the apical left ventricular cavity. Apical cavity pressure was extremely high, up to 330 mmHg—200 mmHg above that in the main left ventricular cavity. Because of the danger of apical rupture and clot formation, we attempted the experimental use of alcohol ablation for effective palliation. We present our pilot experience, offer a novel interpretation of the nature of this obscure entity, and possibly justify a new catheter treatment. In addition, we discuss the developmental, pathophysiologic, and clinical implications of this unusual form of hypertrophic cardiomyopathy. To our knowledge, ours is the first reported use of subselective, modified-protocol alcohol septal ablation to treat an obstructive mid-apical muscular ring in a patient with apical hypertrophic cardiomyopathy.Key words: Cardiomyopathy, hypertrophic/complications/epidemiology/physiopathology/therapy; ethanol/administration & dosage/therapeutic use; heart septum/pathology; hypertrophy, left ventricular/diagnosis; myocardial ischemia/complications; treatment outcomeHypertrophic obstructive cardiomyopathy (HOCM) is a congenital heart condition characterized by ventricular hypertrophy and a progressive worsening of symptoms, as related to the worsening of the subaortic gradient.^1,2 Either traditional surgical septal myomectomy^3,4 or alcohol septal ablation (ASA)^2,4,5 can be used to treat HOCM by effectively reducing the subaortic gradient.^1,2 We describe the case of an elderly woman who had the rarer variant of hypertrophic cardiomyopathy (HCM)—that with apical aneurysm and mid-ventricular obstruction. We describe in detail the experimental use of subselective alcohol ablation to treat the obstructive mid-apical muscular ring in this patient, and we revisit the nature of apical HCM.     

Tratamiento quirúrgico de la mediastinitis necrosante descendente

Introduction

Descending necrotizing mediastinitis (DNM) is a serious infection which occurs as a complication of oropharyngeal infection. Its surgical management and the routine transthoracic approach remain controversial. In this article we report our experience in the management of this disease, and review the different surgical approaches that have been reported in the medical literature.

Material and methods

A retrospective review was made of the clinical records of 29 patients treated between 1988 and 2009. Several demographic variables were analyzed, origin of the initial infection, stage of the disease according to Endo's classification, surgical technique and outcome.

Results

Surgical treatment consisted of both cervical and mediastinal drainage and radical debridement. The mediastinal drainage was made through a transcervical approach in 10 cases and transthoracic in 19, depending on the extent of the mediastinitis. The outcome was satisfactory in 24 patients and 5 died (mortality 17.2%).

Conclusions

According to our results and the conclusions of the main authors, we recommend a prompt and aggressive surgery with a transthoracic approach in cases of widespread DNM.     

The Waterlow score for risk assessment in surgical patients

Introduction

Perioperative scoring systems aim to predict outcome following surgery and are used in preoperative counselling to guide management and to facilitate internal or external audit. The Waterlow score is used prospectively in many UK hospitals to stratify the risk of decubitus ulcer development. The primary aim of this study was to assess the potential value of this existing scoring system in the prediction of mortality and morbidity in a general surgical and vascular cohort.

Methods

A total of 101 consecutive moderate to high risk emergency and elective surgical patients were identified through a single institution database. The preoperative Waterlow score and outcome data pertaining to that admission were collected. The discriminatory power of the Waterlow score was compared against that of the American Society of Anesthesiologists (ASA) grade and the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM).

Results

The inpatient mortality rate was 17% and the 30-day morbidity rate was 29%. A statistically significant association was demonstrated between the preoperative Waterlow score and inpatient mortality (p<0.0001) and 30-day morbidity (p=0.0002). Using a threshold Waterlow score of 20 to dichotomise risk, accuracies of 0.84 and 0.76 for prediction of mortality and morbidity were demonstrated. In comparison with P-POSSUM, the preoperative Waterlow score performed well on receiver operating characteristic analysis. With respect to mortality, the area under the curve was 0.81 (0.80–0.85) and for morbidity it was 0.72 (0.69–0.76). The ASA grade achieved a similar level of discrimination.

Conclusions

The Waterlow score is collected routinely by nursing staff in many hospitals and might therefore be an attractive means of predicting postoperative morbidity and mortality. It might also function to stratify perioperative risk for comparison of surgical outcome data. A prospective study comparing these risk prediction scores is required to support these findings.