Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials

BACKGROUND: In general practice, acute sinusitis is frequently diagnosed and treated with antibiotics. OBJECTIVE: This study aimed to determine the evidence for the effectiveness of antibiotic treatment in acute maxillary sinusitis in adults by assessing the methodological quality of placebo-controlled double-blind randomized trials. METHOD: An evaluation by four raters through a 35-item scoring-scale for internal and external validity of all placebo-controlled double-blind randomized trials on acute sinusitis found between January 1966 and July 1996. RESULTS: Eighty-five trials were excluded because they were not placebo-controlled, double-blind, randomized, or were carried out in patients with chronic sinusitis or in children. The three remaining trials were performed in different populations (one in general practice) between 1973 and 1978. Only one study claimed superiority of antibiotic treatment. Different inclusion criteria and major outcome measures were used by the authors. The reliability of major outcome events was reported poorly or not at all and in two studies outcome measures were clinically inappropriate. The studies scored 30-62% of the maximum attainable score for internal validity and 10-20% for external validity. CONCLUSION: The effectiveness of antibiotic treatment in acute maxillary sinusitis in a general practice population is not based sufficiently on evidence.      

Convergence of occipital nerve and superior sagittal sinus input in the cervical spinal cord of the cat

Co-existence of facial and occipital pain may occur in occipital neuralgia, migraine and cluster headache; suggesting convergence of trigeminal and cervical afferents. Such convergence has been shown in humans and other animals, but the site and extent of this are uncertain. In anaesthetized adult cats, the superior sagittal sinus and occipital nerve were stimulated electrically, and extracellular recordings made in the dorsolateral area of the upper cervical cord using glass-coated tungsten electrodes. Of 49 units in 10 cats, 33 (67%) had input from the superior sagittal sinus and the occipital nerve. Thirteen (27%) had superior sagittal sinus input and 3 (6%) had occipital nerve input. Convergent receptive fields were identified mechanically in 7 units. These experiments in cats show convergent input from occipital nerve and superior sagittal sinus on dorsolateral area units in two-thirds of cases studied. This experimental site of trigeminocervical convergence may relate to referral of pain in occipital neuralgia and other headaches.     

Nonsteroidal anti-inflammatory drugs (NSAIDs) and the kidney

In patients with PG-dependent renal function, NSAID administration constantly reduces GFR and RBF in a dose-dependent fashion. In this situation, the risk of overt acute renal failure is high and should be taken into proper account. In contrast, the incidence of NSAID-related renal structural alterations appears to be very low, yet the absolute number of patients may be significant considering the wide use of such drugs. Concerning the antiproteinuric effect of NSAIDs, the unfavourable ratio risk/benefit does not seem to support their indication in proteinuric nephropathies. The development of PGHS-2 selective inhibitors is promising, and may open new therapeutical strategies in the treatment of the progression of renal disease.      

Insulin, chemotherapy, and the mechanisms of malignancy: the design and the demise of cancer

The endogenous molecular biology of cancer cells involves autocrine and paracrine secretion of insulin and insulin-like growth-factors I and II, which subserve energy production and growth stimulation, respectively, in these cells. These activities confer on cancer its malignant potential, working as they do autonomously, free from higher levels of integrated control. Taking advantage of cancer's mechanisms of malignancy by employing exogenous insulin as a biologic response modifier, it is possible to potentiate the cytotoxic effects of chemotherapeutic agents for improved treatment of cancer. A synergy between certain membrane and metabolic effects of insulin on cancer cell molecular biology increases anticancer drug efficacy, and it does so with reduced doses of the drugs, enhancing their safety. This treatment strategy has been applied abroad over the last five decades with very promising clinical results.     

双—对二甲氨基苯甲醛缩二胺类希夫碱合成、表征及抗菌活性

目的：合成双－对二甲氨基苯甲醛缩二胺类希夫碱,并对其抗菌活性进行研究。方法：以对二甲氨基苯甲醛和二胺类为原料,经缩合反应,制得4种相应希夫碱。结果：结构经元素分析、红外光谱、核磁共振谱确定,4种化合物均未见文献报道,抗菌活性测试表明,它们具有一定抗菌活性。结论：乙酸是催化剂,对缩合反应有利,希夫碱化合物具有一定抗菌活性。     

Psychotic symptoms, aggression and restlessness in dementia

The current article reviews the literature pertaining to psychosis, aggression and restlessness in dementia sufferers examining frequency, course and associations as well as treatment considerations. All of these problems are highly prevalent, with a high impact upon dementia sufferers and their carers. Although there has been an expansion in this literature over the last few years there are still very few studies describing the natural course of behavioural and psychological symptoms in dementia (BPSD) and a paucity of data relating to non-Alzheimer dementias. Several large treatment studies have recently been completed, but there are still very few double blind controlled trials focusing upon BPSD in particular respect to non-pharmacological interventions.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: FUNCTIONS OF ANGIOTENSIN PEPTIDES IN THE ROSTRAL VENTROLATERAL MEDULLA

• 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
• 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
• 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
• 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.

     

Paradoxical effects of viscosity on the VentrAssist rotary blood pump

The ability of the VentrAssist blood pump to perform at its optimum design point is determined by a number of factors such as geometry of the pump, surface roughness, and fluid properties. Once the fluid properties are known, the performance characteristics of the pump can be optimized for that fluid. It is important to understand the effects of dynamic viscosity mu (called simply viscosity hereafter) on the performance characteristics and stability of the pump. The performance envelope of the pump and the needs of the patient must be matched. The VentrAssist pump has no shaft, seals, or fixed bearings and relies on the fluid-dynamic forces to maintain its effective performance. A number of different fluids have been tested to determine the effects of viscosity and density on pump performance. These include aqueous glycerol, red blood cells (RBCs) suspended in phosphate buffered saline solution (PBS), and Haemaccel. The effects of viscosity on the bearing stiffness, stage efficiency, and the pressure-flow rate (HQ) are characterized. The experimental results show a slight increase in the pressure rise across the pump shown as a positive upward shift of the H-Q curves with a decrease in viscosity; however, this is relatively small. A paradox in system efficiency exists: for a given fluid asymptotic viscosity, the system efficiency (product of magnetic and stage efficiency) using Haemaccel or PBS is greater than for the same viscosity of aqueous glycerol.     

Sensorless flow and head estimation in the VentrAssist rotary blood pump

Flow rate and pressure difference (or head) are key variables needed in the control of implantable rotary blood pumps. However, use of flow and/or pressure probes can decrease reliability and increase system power consumption and expense. For a given fluid viscosity, the flow state is determined by any 2 of the 4 pump variables: Flow, pressure difference, speed, and motor input power can be used. Thus, if viscosity is known or if its influence is sufficiently small, flow rate and pressure difference can be estimated from the motor speed and motor input power. For the VentrAssist centrifugal blood pump, which uses a hydrodynamic bearing, sensorless flow and pressure head estimation accuracy of 2 of our impeller designs were compared for a viscosity range of 1.2 to 4.5 mPas. This showed impeller design optimization can improve estimation accuracy. We also compared estimation accuracy using 2 blood analogues used in vitro, aqueous glycerol and red blood cells suspended in Haemaccel. The nature of the blood analogue and not only the viscosity of the fluid seems to influence estimation accuracy in our pump.