Local neuromuscular characteristics associated with patellofemoral pain: A systematic review and meta-analysis.

BACKGROUND: Local neuromuscular deficits have been reported in people with patellofemoral pain. We synthesised the neuromuscular characteristics associated with patellofemoral pain to help identify interventional targets and potential mechanisms. METHODS: Five databases were searched for local neuromuscular characteristics in case-control studies. Electromyography, flexibility, muscle performance and cross-sectional area data were derived from functional or isolated task investigations and synthesised accordingly. An evidence gap map was constructed. FINDINGS: Sixty-seven studies were included. In functional tasks, electromyographic investigations showed moderate evidence of small effect for vastus medialis onset-delays relative to vastus lateralis (0.44 [0.03, 0.85]) during stepping/stair negotiation tasks, and higher biceps femoris mean excitation amplitudes (0.55 [0.06, 1.04]) in single-leg triple-hop test. In isolated tasks, we found moderate evidence of medium effect for lower Hoffman-reflex amplitude of vastus medialis (-1.12 [-1.56, -0.67]). Muscle performance investigations showed; strong evidence with medium and small effects for lower extensors concentric (-0.61 [-0.81, -0.40]) and eccentric (-0.56 [-0.79, -0.33]) strength, and moderate evidence of medium effect of lower isometric (-0.64 [-0.87, -0.41]) strength, moderate evidence with small effect for rate of force development to 30% (-0.55[-0.89, -0.21]), 60% (-0.57[-0.90, -0.25]) and medium effect to 90% (-0.76[-1.43, -0.10]) of maximum voluntary contraction, and small effect for lower flexors concentric strength (-0.46 [-0.74, -0.19]) and extensors total work (-0.48 [-0.90, -0.07]). Flexibility investigations showed tighter hamstrings (-0.57 [-0.99, -0.14]). INTERPRETATION: Differences within quadriceps and hamstrings motor-control, hamstrings tightness, and quadriceps and hamstrings weakness are associated with patellofemoral pain, and can be used to guide investigations of treatment effects.

Microfluidics-assisted generation of stimuli-responsive hydrogels based on alginates incorporated with thermo-responsive and amphiphilic polymers as novel biomaterials.

We used a droplet-based microfluidics technique to produce monodisperse responsive alginate-block-polyetheramine copolymer microgels. The polyetheramine group (PEA), corresponding to a propylene oxide /ethylene oxide ratio (PO/EO) of 29/6 (Jeffamine(®) M2005), was condensed, via the amine link, to alginates with various mannuronic/guluronic acids ratios and using two alginate:jeffamine mass ratios. The size of the grafted-alginate microgels varied from 60 to 80 µm depending on the type of alginate used and the degree of substitution. The droplet-based microfluidics technique offered exquisite control of both the dimension and physical chemical properties of the grafted-alginate microgels. These microgels were therefore comparable to isolated grafted-alginate chains in retaining both their amphiphilic and thermo-sensitive properties. Amphiphilicity was demonstrated at the oil-water interface where grafted-alginate microgels were found to decrease interfacial tension by ∼ 50%. The thermo-sensitivity of microgels was clearly demonstrated and a 10 to 20% reduction in size between was evidenced on increasing the temperature above the lower critical solution temperature (TLCST) of Jeffamine. In addition, the reversibility of thermo-sensitivity was demonstrated by studying the oil-water affinity of microgels with temperature after Congo red labeling. Finally, droplet-based microfluidics was found to be a good and promising tool for generating responsive biobased hydrogels for drug delivery applications and potential new colloidal stabilizers for dispersed systems such as Pickering emulsions.

Cold gelation of alginates induced by monovalent cations.

A new reversible gelation pathway is described for alginates in aqueous media. From various samples differing by their mannuronic/guluronic content (M/G), both enthalpic and viscoelastic experiments demonstrate that alginates having a high M content are able to form thermoreversible assemblies in the presence of potassium salts. The aggregation behavior is driven by the low solubility of M-blocks at low temperature and high ionic strength. In semidilute solutions, responsive assemblies induce a strong increase of the viscosity below a critical temperature. A true physical gel is obtained in the entangled regime, although the length scale of specific interactions between M-blocks decreases with increasing density of entanglements. Cold setting takes place at low temperatures, below 0 °C for potassium concentrations lower than 0.2 mol/kg, but the aggregation process can be easily shifted to higher temperatures by increasing the salt concentration. The self-assembling process of alginates in solution of potassium salts is characterized by a sharp gelation exotherm and a broad melting endotherm with a large hysteresis of 20-30 °C between the transition temperatures. The viscoelastic properties of alginate gels in potassium salts closely depend on thermal treatment (rate of cooling, time, and temperature of storage), polymer and salt concentrations, and monomer composition as well. In the case of alginates with a high G content, a similar aggregation behavior is also evidenced at higher salt concentrations, but the extent of the self-assembling process remains too weak to develop a true gelation behavior in solution.

Synthesis and rheological properties of responsive thickeners based on polysaccharide architectures.

New thermothickening copolymers were synthesized by grafting responsive poly(ethylene oxide-co-propylene oxide) [PEPO] onto three different polysaccharide backbones: carboxymethylcellulose [CMC], alginate [ALG], and carboxylated dextran [DEX]. The coupling reaction between carboxylic groups of biopolymers and the terminal amine of PEPO was activated at low temperature ( T < 10 degrees C) in water by using carbodiimide and N-hydroxysuccinimide. In these conditions it was shown that the formation of amide bonds strongly depends on the concentration of reactive groups, which is limited by the viscosity of the polymer sample. While a full conversion was obtained for the low molecular weight dextran, the efficiency of grafting remains low (between 30 to 40%) for CMC and alginate, which give a solution of high viscosity even at low concentration. When studied in the semidilute regime, all the copolymer solutions clearly exhibit thermothickening behavior with a large and reversible increase of viscosity upon heating. The association temperature and the gelation threshold were shown to depend on polymer concentration as it is expected from the phase diagram of PEPO precursor. Similarly, the influence of added salt on PEPO solubility in water has been used to control the self-assembling behavior of copolymer formulations. The relative comparison between the three copolymers reveals that the amplitude of the viscosity jump induced by heating mainly depends on the proportion of responsive material inside the macromolecular architecture rather than the dimensions of the main chain. The high increase of viscosity, which can reach several orders of magnitude between 20 degrees C and body temperature, clearly demonstrates the potentiality of these copolymers in biomedical applications like injectable gels for tissue engineering.

Flumazenil-precipitated panic and dysphoria in patients dependent on benzodiazepines: a possible aid to abstinence.

Ten long-term users of benzodiazepines (average daily dose, 20 mg of diazepam or equivalent) who had experienced problems in withdrawing from the drugs were given an i.v. challenge with either the benzodiazepine antagonist flumazenil (1 mg injected over 30 s) or placebo (vehicle solution) in a randomized double-blind design. There were no 'pseudo withdrawal' responses to either single-blind or double-blind placebo injections, whereas flumazenil produced dramatic panic reactions in all four subjects tested, followed by characteristic benzodiazepine withdrawal symptoms. There were also small but significant rises in pulse rate and blood pressure, but no change in serum cortisol. Flumazenil-induced panic could not be entirely accounted for by a past or present diagnosis of panic disorder, and did not seem to be related to previous withdrawal problems, present benzodiazepine dosage, or to the severity of withdrawal symptoms precipitated by flumazenil in the same challenge test. Attempts to reduce benzodiazepine intake over the next 3 weeks tended to be more successful in the flumazenil group. The results are discussed with reference to possible changes in the GABA-benzodiazepine system in long-term benzodiazepine users.

[Disorders of proprioception of the arthrotic knee joint]. / Propriozeptionsstörung am arthrotischen Kniegelenk.

We measured proprioception of the knee joint by an active and a passive method in 40 subjects under 30 years of age and in 80 subjects older than 50 years with no evidence of knee joint disease. Joint position sense was also determined in an additional 59 patients with osteoarthrosis of the knee. Proprioception was found to decline with increasing age. In the osteoarthritic knee the measured values were significantly higher than in both groups without knee-joint involvement. An elastic bandage had a positive effect. There was a positive correlation between proprioception and clinical parameters. Walking ability and range of motion did not significantly influence the proprioception. Patients receiving physical therapy showed an improved joint position sense.

Early intervention in psychiatric emergencies: a controlled clinical trial.

In the UK, psychiatric care of patients with acute and chronic disorders has increasingly moved from hospital to the community. We have evaluated in a controlled trial patients with severe mental illness, who were assigned to early intervention by community services or to standard hospital treatment. 100 patients aged 16 to 65 years presenting as psychiatric emergencies to an inner London teaching hospital were randomly allocated to a multidisciplinary community-based team (n = 48) or conventional hospital-based psychiatric services (n = 52) and assessed over a 3-month period. Ratings of psychopathology and social functioning were made before treatment and after 2, 4, and 12 weeks by independent assessors. 85 patients completed all assessments, and all patients had evaluable data beyond 2 weeks. 3 patients died during the study, 2 from natural causes and 1 from an accident. Patients referred to the community service showed greater improvement in symptoms and were more satisfied with services than those in the hospital-based service. Patients treated in the hospital-based service spent eight times as many days as psychiatric inpatients as those treated in the community-based service. Patients both prefer and seem to benefit from community-based psychiatric care, and our early-intervention community service might be a good model for such care.

[Benign tumors of the stomach]. / Tumorile benigne ale stomacului.

In 19 cases of benign tumors of the stomach (representing 4,8% of a total of 417 cases of gastric tumors hospitalized between 1969 and 1975) the authors stress the difficulties of the early diagnosis, the non-characteristic symptomatology, as well as the fact that the patients are hospitalized mostly for acute complications (upper digestive hemorhages). The type of expresis depends on the location and the extension of the tumors.

Living with the dying: use of the technique of participant observation.

Through participant observation, questions concerning optimal care of dying patients and needs of their families were answered. A general surgical ward and a palliative care unit were the sites of observation. The observations support the belief that a palliative care unit, specifically designed to meet the known needs of dying patients and their families, is preferable to a general surgical ward. The main findings, of less concern in the palliative care unit than on the surgical ward, were the following: the importance of patient-to-patient support; the discomfort of sick-role behaviour; the impersonal and sometimes intimidating nature of patient care; the limitation of the patient's need (as a person) to give as well as to receive; and the value of families, student nurses and volunteers in total care. These findings emphasize the importance of personal interest in relieving the distress suffered by many terminally ill patients.