Detection and differentiation of Vibrio spp. in seafood and fish samples with cultural and molecular methods.

Vibrio spp. as natural inhabitants of sea- and brackwater of both tropical and temperate regions of the world are commonly found in different kinds of seafood. Even among the three main human pathogenic species Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus most of the isolates from seafood do not carry the different virulence factors responsible for foodborne infections. Therefore, the risk assessment of Vibrio spp. in seafood is currently based mainly on the knowledge of the genetic setting of foodborne strains. For the detection and differentiation of Vibrio spp. (V. parahaemolyticus, V. cholerae and V. vulnificus) three probe-based multiplex real-time PCR systems were developed and validated. One real-time PCR system simultaneously detects V. parahaemolyticus, V. cholerae and V. vulnificus on genus level combined with an Internal Amplification Control. The detection limit for the system was between 1cfu/mL and 10cfu/mL in pure culture and in different artificially contaminated sample material, e. g. prawns or Alaska Pollock. The other two PCR systems were implemented for the detection of different virulence genes of V. parahaemolyticus and V. cholerae isolates. The molecular detection systems were applied for the investigation of 338 raw and cooked seafood and fish samples for the presence of the different Vibrio spp. The collected data indicate that the PCR systems can be useful for rapid detection and differentiation of Vibrio spp. in different food matrices as basis for a preventive consumer protection policy.

The biomechanics of a thumb carpometacarpal immobilization splint: design and fitting.

Splinting for the common osteoarthritis of the carpometacarpal (CMC) joint of the thumb is infrequently described in the literature, but the few splints that are described include one or both adjacent joints. This paper describes the design and biomechanics of a custom-molded thumb CMC immobilization splint that excludes the thumb metacarpophalangeal and wrist joints. The problem of the imbalance of extrinsic extensor/abductor forces against the intrinsic flexor/adductor forces is described. The accompanying weakening of the thumb CMC capsule allows dorsal shifting of the proximal end of the metacarpal, producing pain. The splint described in this paper 1) prevents motion of the first metacarpal in relation to the other metacarpals, 2) prevents tilting (flexion) of the first metacarpal during pinch, and 3) allows unrestricted thumb metacarpal and wrist joint motion. Attention to detail during construction is required for an accurate pattern, precise positioning of the CMC joint during molding, accurate molding around the first metacarpal, and well-distributed pressure. This design may also be used for protection following thumb CMC arthroplasty or thumb CMC sprain or strain and as a base for thumb metacarpophalangeal and/or interphalangeal mobilization splinting.

Effect of chronic pulmonary denervation on ventilatory responses to exercise.

To assess the role of intrapulmonary receptors on the ventilatory responses to exercise we studied six beagle dogs before and after chronic pulmonary denervation and five dogs before and after sham thoracotomies. Each exercise challenge consisted of 6 min of treadmill exercise with measurements taken during the third minute at 3.2 km/h, 0% grade, and during the third minute at 5.0 km/h, 0% grade. Inspiratory and expiratory airflows were monitored with a low-dead-space latex mask and pneumotachographs coupled to differential pressure transducers. Both pre- and postsurgery, all dogs exhibited a significant arterial hypocapnia and alkalosis during exercise. Denervation of the lungs had no significant effect on minute ventilation at rest or during exercise, although there was a lower frequency and higher tidal volume in the lung-denervated dogs at all measurement periods. Breathing frequency increased significantly during exercise in lung-denervated dogs but to a lesser magnitude than in the control dogs. The changes that occurred in breathing frequency in all animals were due predominantly to the shortening of expiratory time. Inspiratory time did not shorten significantly during exercise following lung denervation. We conclude from these data that intrapulmonary receptors which are deafferented by sectioning the vagi at the hilum are not responsible for setting the level of ventilation during rest or exercise but are involved in determining the pattern of breathing.

Bone injuries: treatment and rehabilitation.

Solid bony union with full range of painless motion is accomplished by correct early diagnosis, adequate reduction, stable fixation, prevention of edema, and institution of early motion programs. The degree of bony injury and involvement of multiple tissues will dictate the type of fixation and length of immobilization. Restoration of a stable skeleton with a functional range of joint motion must always be accomplished.

Effects of chronic right-to-left cardiac shunt on hypoxic sensitivity of mongrel dogs.

Resting ventilation (VI), blood gases, hypoxic sensitivity, and the ventilatory responses to intravenous sodium cyanide (NaCN, 100 micrograms/kg), doxapram (DOX, 500 micrograms/kg), and dopamine (DOPA, 20 micrograms/kg) were analyzed in four normal mongrel dogs (group I-N) and seven mongrel dogs with chronic (5-11 yr) right-to-left cardiac shunt (group II). The group I-N animals were also studied during steady-state isocapnic hypoxia (group I-H). The shunt procedure used for these studies produced a model for ventilatory studies during chronic shunt hypoxemia. The increases in VI per percent decrease in O2 saturation, which occurred during a four-breath N2 test, were 30, 43, and 13 ml X kg-1 X min-1 in groups I-N, I-H, and II, respectively. The decrease in hypoxic sensitivity of the group II animals, compared with groups I-N and I-H, occurred in the presence of an increase in PaCO2 from 21.9 to 26.0 Torr during the four-breath N2 test. A decrease in PaCO2 from 34.7 to 30.0 and from 33.6 to 30.4 Torr was observed in groups I-N and I-H. The response to DOX, a general analeptic agent, was greatest in group II and least in group I-N. However, the ventilatory responses to NaCN and DOPA were not sufficiently different among the three groups to suggest a difference in carotid body function as assessed by these drugs.

Effects of isoflurane on the baroreceptor reflex.

The baroreceptor reflex has been found to be attenuated during anesthesia, but the effects of the relatively new anesthetic, isoflurane, on baroreflex function have not been examined thoroughly. This study was performed to determine the effects of isoflurane on each component of the baroreceptor reflex arc, including the receptors, afferent and efferent nerve pathways, central integratory centers, peripheral ganglia, and the heart. Baroreflex effects on heart rate initiated by systemic pressure changes were examined in conscious and anesthetized dogs (1.3% and 2.6% isoflurane). The effects on individual components of the reflex arc were determined by examining carotid sinus baroreceptor afferent activity, sympathetic efferent nerve activity, and heart rate response to direct sympathetic and parasympathetic efferent nerve stimulation in anesthetized dogs. Preganglionic and postganglionic nerve activities were recorded simultaneously during baroreflex activation to determine ganglionic effects of isoflurane. Baroreflex-induced changes in heart rate were not depressed significantly until 2.6% isoflurane if blood pressure changes due to anesthetic administration were prevented. Significant decreases in baseline sympathetic efferent nerve activity were found at 1.3% and 2.6% isoflurane, with depression of postganglionic activity significantly greater than preganglionic activity at 2.6% isoflurane, indicating a ganglionic effect of isoflurane. Cardiac chronotropic responses to direct stimulation of sympathetic and vagal fibers were attenuated significantly by isoflurane, with sympathetic stimulation showing the greater sensitivity to the anesthetic. Carotid baroreceptor afferent activity was increased by isoflurane, and this sensitization of the baroreceptors appeared to contribute to the decreased levels of sympathetic tone. Therefore, although isoflurane was found to alter the baroreceptor reflex through its effects at multiple sites of the baroreflex arc, significant depression of the cardiac chronotropic component of the reflex was seen only at 2.6% isoflurane.

Lidocaine and bupivacaine differential blockade of isolated canine nerves.

In vitro studies of pharmacologic actions of local anesthetics are usually performed at room temperature using amphibian nerves exposed to local anesthetics for substantial periods of time. We performed in vitro studies of pharmacologic responses of motor A fibers and sensory C fibers to lidocaine and bupivacaine in clinically effective concentrations using a canine nerve preparation at body temperature with short exposure times to evaluate responses under clinically relevant conditions. Differential blockade of isolated, desheathed phrenic and vagus nerves was achieved with bupivacaine (0.58 mM), C fibers being blocked before A fibers (P less than 0.05). Lidocaine (2.8 mM) did not block A and C fibers differentially.

Pulmonary denervation in the dog.

To produce a chronically lung-denervated animal model, a single-stage surgical procedure was performed on five beagle dogs. A left thoracotomy allowed hilar stripping of the pulmonary contributions to the left vagus nerve and transection of the right vagal trunk. The criterion for denervation was defined as the absence of the Hering-Breuer reflex (HBR). The five denervated dogs (DD) as well as five control dogs (CD) were evaluated for presence of the HBR under pentobarbital sodium (Nembutal, 30 mg/kg) anesthesia. Between the 3rd and 8th wk postsurgery, the HBR was clearly abolished in the DD but present in the CD. By the 12th-14th wk postsurgery, the HBR was again present in the DD. This relatively uncomplicated surgical procedure effectively produced a lung-denervated animal model. However, reinnervation occurred relatively soon, thus demonstrating the importance of regular frequent evaluation of the HBR when using this and any other surgically produced pulmonary denervation model.

Low profile dynamic splinting of the injured hand.

Dynamic splinting is a well-accepted modality in gaining joint motion in the injured hand. Presented is a splinting design system referred to as "low profile" dynamic splinting whereby high outriggers are avoided. A review of the literature reveals that this technique is based on the original design approach used by Dr. Sterling Bunnell. Described are the basic principles of the low profile design system, with illustrations of the system in specific splints and specific construction details. This splinting system is indicated for a stiff hand that has sustained direct trauma. Hands with a muscle imbalance secondary to a central nervous system or peripheral nerve lesion require a different splinting approach, which is not within the scope of this paper.

Reflex effects of thoracic sympathetic afferent nerve stimulation on the kidney.

Thoracic sympathetic afferents may play a role in the reflex control of renal vascular resistance during hypotension. Mongrel dogs were anesthetized with ketamine hydrochloride and maintained on a 50-50, O2-N2O mixture supplemented with 0.5%-1.0% halothane. Systemic arterial blood pressure was lowered to 50 mmHg with use of a constant pressure hemorrhage technique. The renal circulation was perfused with a constant-flow perfusion system. Low-frequency (3 Hz) stimulation of thoracic sympathetic afferents produced renal vasodilation. A reduction of renal vascular resistance was measured as a decrease in constant-flow perfusion pressure. Vagotomy accentuated the dilator response to stimulation. High-frequency (30 Hz) afferent stimulation produced renal vasoconstriction. Renal efferent nerve activity and renal blood flow responded to afferent stimulation (3 Hz) by transient inhibition of efferent activity and increases in renal blood flow. Afferent stimulation (30 Hz) caused increases in renal efferent nerve activity and decreases in renal blood flow. The thoracic sympathetic afferents carry information from cardiopulmonary structures that alter renal efferent nerve activity and renal hemodynamics during hypotension.