Droplet applicator module for reproducible and controlled endoscopic laryngeal adductor reflex stimulation.

This work presents a droplet applicator module to generate stable droplets with different muzzle energies for the reproducible endoscopic stimulation of the laryngeal adductor reflex (LAR). The LAR is a protective reflex of the human larynx; an abnormal LAR performance may cause aspiration pneumonia. A pathological LAR can be detected by evaluating its onset latency. The reflex can be triggered by shooting a droplet onto the laryngeal mucosa, which is referred to as Microdroplet Impulse Testing of the LAR (MIT-LAR). Stimulation intensity variation is desired as the reflex threshold may vary inter-individually. The kinetic energy of a droplet after detachment from the nozzle, i.e., its muzzle energy, is considered an appropriate metric for the LAR stimulation intensity. In this work, a suitable nozzle channel geometry is identified based on the experimental evaluation of droplet formation using three different nozzle channel geometries. Two nontoxic additives are evaluated regarding their effect on fluid properties and droplet formation. The range of achievable droplet muzzle energies is determined by high-speed cinematography in association with a physically motivated model of the macroscopic droplet motion. The experimental results show that sodium chloride is a suitable additive to enhance droplet stability in the studied parameter range with the proposed system. Droplet muzzle energy variation from 0.02 µ J to 1.37 µ J was achieved while preserving the formation of a single stimulation droplet. These results are an important prerequisite for a safe and reproducible LAR stimulation by MIT-LAR, which could also help to further elucidate the physiological mechanisms underlying this laryngeal reflex.

[Cases from the area between geriatrics and trauma surgery. Examples from the medical arbitration board]. / Fälle aus dem Grenzgebiet zwischen Geriatrie und Unfallchirurgie. Aus der Arbeit der Schlichtungsstelle.

Medical arbitration boards ("Schlichtungsstellen", expert panels for extrajudicial malpractice claim resolution) try to settle claims of suspected malpractice between patients and their physicians and to avoid court trials. Numerous studies found an increasing incidence of adverse events with rising age. Injuries that occur in the hospital are frequently beyond the specialty of the treating physician. Therefore, the physician has to broaden his diagnostic view beyond the borders of his own specialty to recognize injuries in his patients and to prevent malpractice claims.In this paper, we report on adverse events in elderly patients where the geriatrician/internist was accused of negligence for not having promptly recognized a fracture after a fall or having chosen an inadequate operative procedure. For example, the importance of weight bearing osteosynthesis, mandatory in hip fractures in the elderly population to prevent long-term immobilization, is discussed.Adverse events due to negligence are more frequent among the elderly; the reasons are discussed. They will never be entirely preventable. The data presented in this report may be helpful to recognize fractures in time and to ensure adequate treatment, in order to reduce the number of court claims.

Valsartan versus ACE inhibition after bare metal stent implantation--results of the VALVACE trial.

The use of ACE inhibitors (ACE-i) represents an Ia recommendation in the treatment of patients with STEMI and NSTEMI. However, results of smaller studies suggest an increase of in-stent-restenosis under ACE-i administration. The effects of ACE-i and valsartan after bare metal stent implantation of the culprit type B2/C lesion should be compared. Seven hundred patients were treated either by ACE-i in cases of LVEF<50% or 80 mg valsartan in cases of LVEF> or =50%. Restenosis rates after 6 months were analysed in 399 patients under valsartan and 224 patients under ACE-i with control angiography and major adverse cardiac events (death, infarction, reintervention) in a follow-up of up to 4 (mean 2.6) years in all patients. In-stent-restenosis was found in 19.5% under valsartan and in 34% under ACE-i (p<0.005). In diabetic patients, restenosis occurred in 24% under valsartan and in 43% under ACE-i (p<0.01). In initial acute coronary syndrome (ACS), restenosis rate was 14% under valsartan and 43% under ACE-i (p<0.0001). In stable angina, restenosis rates were 26.5% and 27.5%, respectively. Total MACE rates revealed significant differences in ACS due to reintervention rates of 22% and 7% under ACE-i and valsartan (p<0.0001). The administration of 80 mg valsartan after bare metal stent implantation leads to a reduction of in-stent-restenosis compared to ACE-i. This effect is mainly due to beneficial effects of valsartan in cases with initial ACS. Major differences between ACE-i and valsartan are discussed including inflammation, activation of neutrophils, mode of bradykinin activation, AT2 receptor stimulation and apoptosis of smooth muscle cells.

Biomechanical qualities of threaded acetabular cups.

We examined 25 different threaded cups using a specific biomechanical procedure. Great differences between the tested cups concerning their biomechanical parameters could be found. There is some evidence that the design of several cups might be inappropriate for stable acetabular fixation, and this may be the reason for early loosening. The new procedure is the first to allow biomechanical assessment of threaded cups by using quantified data, which correspond to long-term stability of the cup.

Mycoses in AIDS.

Major changes are occurring in the epidemiology of opportunistic infections (OI) in patients with acquired immune deficiency syndrome (AIDS) and treated with highly active antiretroviral therapy (HAART). A marked decrease of minor and major OI was observed and clinical resistance of thrush to antifungal agents became extremely rare. Primary and secondary prophylaxis against Pneumocystis carinii infections can be stopped; however, the situation is less clear for other OI such as cryptococcosis or endemic mycoses. The epidemiology is dramatically different in the countries which cannot afford the cost of HAART for the majority of patients, such as South Africa. These topics will be discussed in this paper.

Functional treatment of humeral shaft fractures: indications and results.

OBJECTIVE: To determine effectiveness of closed functional bracing for humeral shaft fractures. DESIGN: Retrospective. SETTING: University. PATIENTS: Eighty-seven patients with humeral shaft fractures. INTERVENTION: All patients were treated with closed functional bracing. MAIN OUTCOMES MEASURED: Both subjective and objective criteria were measured. Objective criteria consisted of range of motion and radiographic measurements. Subjective data were recorded using the Hannover Shoulder Score. RESULTS: Eighty-six percent of the follow-up group showed no restrictions in the movement of their shoulder and elbow joints. On the basis of subjective criteria, 95% of the patients were content with the functional treatment, 65% claimed to be pain free in their daily activities and at work, and 35% felt pain only when doing vigorous activities or heavy physical work. Although malposition with an angulation greater than 10 degrees was observed in ten patients (12.6%), functional outcome was good or excellent in two thirds of the cases followed up. CONCLUSIONS: When the correct indications are present, functional treatment of humeral shaft fractures has proven to be an excellent method that is both reliable and cost effective.

[Functional fracture treatment of the forearm. The indications and results]. / Die funktionelle Knochenbruchbehandlung am Unterarm. Indikationen und Ergebnisse.

In a retrospective study from 1986 to 1995, 64 forearm fractures were treated with brace. Clinical and roentgenographic follow-up data were available for 49 patients (76.6%). There were 49.0% ulna shaft, 38.9% radius and 12.2% forearm fractures. The average time to healing was 10.2 weeks. Functional results were excellent in 57.1%, good in 34.7% and poor in 8.2% of cases. Two (4.1%) fractures (radius, forearm shaft) were not considered as healed and were re-operated with plate osteosynthesis. The ideal indication for fracture bracing is ulna shaft fracture. Radius and forearm shaft fractures can also be treated, but patients must be informed about the long time to healing and operative alternatives.

[Sarmiento function fracture treatment of the tibia]. / Die funktionelle Knochenbruch-Behandlung am Unterschenkel (nach Sarmiento).

Sarmiento's functional brace treatment of tibial bone fractures is introduced and discussed. After fixation with a plaster cast and extension, the injured limb is fitted into a synthetic brace until complete bony union is achieved. Our four years of experience with 73 patients and the distribution of age, sex, localization, and cause are presented, as are the reexamination results. The possible complications and their treatment are demonstrated. The results justify extensive use of this method.

[Biochemical characterization and differentiation of dopaminergic supersensitivity in the rat]. / Zur Frage der biochemischen Charakterisierung und Differenzierung der dopaminergen Supersensitivität bei der Ratte.

Parameters of dopamine turnover were measured after developing different forms of behaviour facilitation. The state of denervation supersensitivity is characterized biochemically by diminished dopamine turnover and enhanced receptor sensitivity whereas forms of innervation supersensitivity did not show such alterations.

[Effect of sodium nitroprusside and nitroglycerin on the resistance and capacitance system in cardiac surgery interventions]. / Die Wirkung von Natriumnitroprussid und Nitroglycerin auf das Widerstands- und Kapazitätssystem bei kardiochirurgischen Eingriffen.

The whole-body arterial and venous dilating properties of nitroglycerin (NTG) and sodium nitroprusside (SNP) were investigated during extracorporeal circulation and normal circulation in patients undergoing coronary bypass surgery. SNP was found to lower preload and afterload for the time of drug administration. During extracorporeal circulation and normal circulation, an average volume of 340 ml was stored in the capacitance vessels when the mean arterial pressure was lowered for 20 mm Hg. When the reduction in preload was compensated by a volume load (blood transfusions), this resulted in a pure impedance reduction by SNP. NTG showed more complex effects. Even with the continuous infusion of NTG only a short-termed, self-limiting afterload reduction occurred during extracorporeal circulation. During normal circulation, the reduction in preload was more extensive with NTG than with SNP, an average volume of 600 ml was stored in the capacitance vessels when the mean arterial pressure was lowered for 20 mm Hg by NTG. While the volume storage by SNP was reversible after termination of the infusion, this was not the case with NTG, where the volume was stored for 1-2 hours. The volume storage by NTG became smaller with an increased filling of the capacitance system. Additionally, the venous resistance of the cardiopulmonary bypass showed different effects on the volume storage by SNP and NTG. In conclusion, the different effects of NTG and SNP cannot be explained by a single, homogenous compartment model of the peripheral circulation but by affecting two different compartments of the capacitance system.

[Dopamine sensitivity of brain-induced behavior after repeated administration of dopamine agonists and antagonists]. / Dopaminsensitivität von Hirngebieten nach wiederholter Gabe von Dopaminagonisten und -antagonisten.

Comparative investigations were carried out on dopamine sensitivity, as judged by the rotational behavior of rats, of different nuclear areas of the central nervous system following repeated application of dopaminergic agonists, or the dopamine antagonist, haloperidol. In the mesolimbic area and in the Nucleus caudatoputamen, repeated pretreatment with amphetamine alone or in combination with another agonist did not result in a change of sensitivity to dopamine. In contrast, dopamine sensitivity of these target areas increased strongly by repeated pretreatment with haloperidol. Pretreatment with dopaminergic agonists distinctly increased the rotation intensity following dopamine injection into the Globus pallidus and Substantia nigra, whereas haloperidole pretreatment reversed the rotational direction after pallidally injected dopamine, and left unaffected the sensitivity of the Substantia nigra. Thus, repeated treatment with dopaminergic agonists produces different patterns of sensibilization. This does lend support to the hypothesis that behavioral facilitation and dopaminergic supersensitivity are mediated differently.

[The effects of REM sleep deprivation on the motor behavior of rats]. / Auswirkungen des REM-Schlafentzuges auf das motorische Verhalten von Ratten.

The effects of rapid-eye-movement (REM) sleep deprivation for 72 h on motor behaviour of rats have been studied. It has been shown both an increased spontaneous locomotor activity and an enhanced rotational behaviour after unilateral intrastriatal injection of dopamine 24 h and 48 h after the end of REM sleep deprivation. The enhancement of motor activity after REM sleep deprivation points to changes in the dopaminergic transmission system. But it is not yet clear, if the main cause of these effects is the development of a super-sensitivity of postsynaptic dopaminergic receptors. In the same way interactions between the dopaminergic system and other inhibitory transmission systems may play an important role, explaining effects of REM sleep deprivation.

[Dopaminergic sensitivity after ethanol pretreatment and its relation to alcohol preference]. / Dopaminerge Sensitivitätsänderungen nach Athanolvorbehandlung und ihre Beziehung zur Alkoholpräferenz.

The interactions between ethanol and the central dopaminergic synaptic transmission also refer to the ethanol drinking behaviour. In mice the alteration of the locomotoric activity induced by apomorphine is influenced by ethanol pretreatment for 28 days in a different way referring to drinking behaviour. Ethanol preferent animals do not differ significantly from the ethanol untreated animals in respect to the apomorphine induced locomotion. The nonpreferent animals show, by comparison, a decrease of the sedative effect of low apomorphine doses (0.25 mg/kg; i.p.) and an increase of the stimulating effect of higher doses (1.0 mg/kg; i.p.). These behavioural alterations may be understood as an expression of dopaminergic presynaptic subsensitivity and of a postsynaptic supersensitivity in ethanol pretreated nonpreferent animals.

[Learning behavior in rats after chronic haloperidol treatment]. / Lernverhalten von Ratten nach chronischer Haloperidolvorbehandlung.

The effect of 3 week chronic haloperidol treatment has been investigated in rats by retention of active avoidance (pole jumping). In the period of dopaminergic supersensitivity, i.e. after withdrawal of haloperidol, pretreated rats showed a better retention of the learned reaction than controls. The results demonstrate that the neuroleptic-induced supersensitivity enhanced not only the spontaneous and stimulated locomotor activity, but also improved the retention of an active avoidance reaction.

Effects of nootropic drugs on dopaminergic systems in the CNS.

The effect of 3 nootropic drugs, meclofenoxat (MEC), piracetam (PIR) and orotic acid (methylglucamine orotate, MGO), on locomotor activity and on rotational behavior after intracerebral injection of dopamine was tested in female Wistar rats. Whereas MGO-pretreatment increased the dopaminergic supersensitivity following repeated haloperidol in both behavioral tests, the other nootropics were without influence on intensity and duration of supersensitivity. Stimulating and sedative action of apomorphine on locomotion (following 2 mg/kg and 40 micrograms/kg apomorphine sc, respectively) was found to be unchanged after single doses of nootropics (300 mg/kg PIR or MEC, 225 mg/kg MGO, 30 min before apomorphine). Preceding systemic application of nootropics did not change the rotational behavior following application of dopamine (200 micrograms/2 microliters) into nucleus accumbens or nucleus caudatoputamen. The results show that nootropic drugs are without influence on spontaneous and dopaminergically stimulated locomotor activity but in contrast to PIR and MEC, MGO is able to facilitate the dopaminergic supersensitivity.

Do cholinomimetics specifically antagonize rotational behavior?

Asymmetries of body posture and movement (rotational behavior) following intracerebral application of dopamine (DA, 200 micrograms/2 microliters) or carbachol (30 and 60 micrograms/2 microliters) were diminished by systemically applied oxotremorine (0.5-1.0 mg/kg IP). The combined intracerebral injections of DA and carbachol show localization-specific effects in caudate nucleus, substantia nigra and globus pallidus. The experiments point to specific dopaminergic-cholinergic interaction in different brain regions. Systemically applied cholinomimetics exert a generally suppressive action on motoric effects.

[Age related alterations of motor behavior and release of dopaminergic supersensitivity in rats]. / Altersbedingte Veränderungen des motorischen Verhaltens und der Auslösbarkeit der dopaminergen Supersensitivität bei Ratten.

Rats aged greater than or equal to 18 months show, aside from clearly diminished motor parameters (exploratory behavior, resting activity, nocturnal activity profile, rotation behavior), after intracerebral dopamine injection a considerably lower apomorphine hypermotility than young animals. The characteristic alteration of activity occurring in young rats during and following chronic administration of haloperidol (1 mg/kg . day, s.c. for 21 days) as an expression of developing dopaminergic supersensitivity does not appear in older animals. Repeated application of amphetamine (2 X 2 mg/kg daily) caused a significant increase in hypermotility. The results are interpreted as the consequence of a age-related reduction of the activity of central-dopaminergic transmission systems and are discussed with regard to possible differences in the realization of agonist- or antagonist-induced supersensitivity.