Distribution of sole Pacinian corpuscles: a histological study using near-term human feet.

INTRODUCTION: Fast-adapting afferent input from the sole Pacinian corpuscles (PCs) is essential for walking. However, the distribution of PCs in the plantar subcutaneous tissue remains unknown. MATERIALS AND METHODS: Using histological sections tangential to the plantar skin of eight near-term fetuses, we counted 528-900 PCs per sole. RESULTS: Almost half of the sole PCs existed at the level of the proximal phalanx, especially on the superficial side of the long flexor tendons and flexor digitorum brevis. Conversely, the distribution was less evident on the posterior side of the foot. The medial margin of the sole contained fewer PCs than the lateral margin, possibly due to the transverse arch. In contrast to a cluster formation in the anterior foot, posterior PCs were almost always solitary, with a distance greater than 0.5 mm to the nearest PC. DISCUSSION AND CONCLUSION: Because a receptive field of PCs is larger than that of the other receptors, fewer solitary PCs might cover the posterior sole. In infants, the amount of anterior sole PCs seemed to determine the initial walking pattern using the anterior foot without heel contact. Anterior PCs concentrated along flexor tendons might play a transient role as tendon organs during the initial learning of walking. During a lesson in infants, mechanical stress from the tendon and muscle was likely to degrade the PCs. In the near term, the sole PCs seemed not to be a mini-version of the adult morphology but suggested an infant-specific function.

[Damage to subcutaneous nerves in endovenous laser coagulation of the great saphenous vein]. / Povrezhdenie podkozhnykh nervov pri éndovenoznoi lazernoi koaguliatsii bol'shoi podkozhnoi veny.

The purpose of this study was to assess the incidence of the development of symptoms of damage to subcutaneous nerves after endovenous laser coagulation (EVLC) of the great saphenous vein (GSV), as well as to determine the effect of these symptoms on quality of life (QoL) of patients. Our retrospective study enrolled a total of 119 patients (mean age 50±13.9 years) subjected to 151 isolated EVLC of the GSV. The average volume of the injected anaesthetic per 1 cm of the vein's length amounted to 8.5±1.9 ml. Puncture of the GSV at the level of the thigh was performed in 37 (24.5%) cases, at the level of the crus in 114 (75.5%) cases. The intervention was performed at the power 5-10 W and linear density of energy approximately 70 J/cm. The median of the follow up period amounted to 264 days. The patients were interrogated by phone. The questionnaire included leading, understandable for patients questions about the presence of postoperative complaints characteristic of damage to subcutaneous nerves, as well as the question about the effect of these complaints on quality of life. The complaints characteristic of damage to subcutaneous nerves were reported for 61 (40.4%) operated limbs, with these symptoms decreasing quality of life only in 7 (4.6%) cases. All respondents noted gradual regression of the symptoms with time. The median of symptom relief amounted to 2 months. The analysis of interrelationship between the level of puncture by the thirds of the femur and crus and the damage of subcutaneous nerves demonstrated no statistically significant association (p=0.108), unlike the analysis by the femur/crus level, wherein the infragenicular puncture significantly increased the risk of traumatisation of subcutaneous nerves (p=0.022). No statistically significant differences by the frequency of damage to subcutaneous nerves depending on the power of energy were revealed (p=0.662). The obtained findings make it possible to recommend EVLC, including with puncture of the GSV below the knee, for patients with varicose veins in this basin.

SMAS Fusion Zones Determine the Subfascial and Subcutaneous Anatomy of the Human Face: Fascial Spaces, Fat Compartments, and Models of Facial Aging.

BACKGROUND: Fusion zones between superficial fascia and deep fascia have been recognized by surgical anatomists since 1938. Anatomical dissection performed by the author suggested that additional superficial fascia fusion zones exist. OBJECTIVES: A study was performed to evaluate and define fusion zones between the superficial and the deep fascia. METHODS: Dissection of fresh and minimally preserved cadavers was performed using the accepted technique for defining anatomic spaces: dye injection combined with cross-sectional anatomical dissection. RESULTS: This study identified bilaminar membranes traveling from deep to superficial fascia at consistent locations in all specimens. These membranes exist as fusion zones between superficial and deep fascia, and are referred to as SMAS fusion zones. CONCLUSIONS: Nerves, blood vessels and lymphatics transition between the deep and superficial fascia of the face by traveling along and within these membranes, a construct that provides stability and minimizes shear. Bilaminar subfascial membranes continue into the subcutaneous tissues as unilaminar septa on their way to skin. This three-dimensional lattice of interlocking horizontal, vertical, and oblique membranes defines the anatomic boundaries of the fascial spaces as well as the deep and superficial fat compartments of the face. This information facilitates accurate volume augmentation; helps to avoid facial nerve injury; and provides the conceptual basis for understanding jowls as a manifestation of enlargement of the buccal space that occurs with age.

Neuroanatomical characteristics of deep and superficial needling using LI11 as an example.

OBJECTIVES: To compare the neuroanatomical characteristics of the deep and superficial tissues at acupuncture point LI11 using a neural tracing technique, in order to examine the neural basis of potential differences between deep and superficial needling techniques. METHODS: In order to mimic the situations of the deep and superficial needling, the retrograde neural tracer Alexa Fluor 488 conjugate of cholera toxin subunit B (AF488-CTB) was injected into the muscle or subcutaneous tissue, respectively, at acupuncture point LI11 in eight rats (n=4 each). Three days following injection, the distribution of motor and sensory neurons labelled with AF488-CTB was examined in the spinal cord and dorsal root ganglia (DRG) under a fluorescent microscope. RESULTS: For both types of injection, labelled motor and sensory neurons were distributed on the side ipsilateral to the injection in the spinal cord and DRG between spinal levels C5 and T1. The number of labelled motor neurons following intramuscular injection was significantly higher than subcutaneous injection. By contrast, the number of labelled sensory neurons following subcutaneous injection was significantly higher in number and extended over a greater number of spinal segments compared to intramuscular injection. CONCLUSIONS: These data indicate that the motor and sensory innervation of muscle and subcutaneous tissue beneath LI11 differ, and suggest that acupuncture signals induced by deep and superficial needling stimulation may be transmitted through different neural pathways.

The use of rat spinal reflexes to quantify injection pain.

Pain caused by subcutaneous injections is unpleasant, which may limit patient compliance. The objective of this study was to use spinal reflexes to quantify subcutaneous injection pain. Spinal reflexes were measured using an electromyogram (EMG) test. The effects of injection volume, pH and osmotic pressure were investigated. The EMG responses increased with injection volume and the acidity of the solution but did not depend on the osmotic pressure of the solution. The EMG responses differed for subcutaneously injected sodium chloride and glucose over the same range of osmotic pressures. Pain caused by the subcutaneous injections was unrelated to the osmotic ratio up to approximately 5. The injection pain caused by therapeutic protein solutions was also evaluated. We compared the EMG responses of the adalimumab and etanercept, as the injection of adalimumab is more painful than that of etanercept in humans. The EMG magnitude for adalimumab was twice that induced by etanercept as observed for the EMG tests performed in rats. Therapeutic proteins account for an increasingly large proportion of pharmaceutical drugs. When a high dose of therapeutic proteins is required, the protein solution must often be highly concentrated to reduce the injection volume. For patient comfort, it is critical to reduce injection pain. The EMG test reported here allows subcutaneous injection pain to be quantified and may be useful for optimizing drug formulations.

True and 'choke' anastomoses between perforator angiosomes: part i. anatomical location.

BACKGROUND: Reports of more than two cutaneous perforator angiosome territories being raised successfully in distally based sural flaps are appearing in the literature. Previous anatomical studies have noted that cutaneous arteries, connected by true anastomosis without change in caliber, frequently parallel cutaneous nerves. METHODS: Twenty-four (48 sides) total body lead oxide cadaver injection studies, including seven arterial and two venous neurovascular, were examined, and the results were compared with clinical thermography in Part II. RESULTS: Long branches of cutaneous perforators, connected in a series by true anastomoses, paralleled at variable distances the main trunks of cutaneous nerves in the head, neck, torso, and upper and lower extremities. Specifically, in the leg, an average of 3.2 true anastomoses (range, 1 to 5) connected perforators that paralleled the sural nerve on the back of the calf; and 2.5 (range, 1 to 4) connected perforators on the medial side of the leg. These vascular freeways were paralleled by the short and long saphenous veins, respectively. CONCLUSIONS: True anastomoses frequently connect skin perforators that course in parallel with cutaneous nerves and veins. They provide an explanation for the long viable flaps noted in the leg, and it will be shown in Part II that they can be detected preoperatively with thermography.

Tissue regeneration in vivo within recombinant spidroin 1 scaffolds.

One of the major tasks of tissue engineering is to produce tissue grafts for the replacement or regeneration of damaged tissue, and natural and recombinant silk-based polymer scaffolds are promising candidates for such grafts. Here, we compared two porous scaffolds made from different silk proteins, fibroin of Bombyx mori and a recombinant analog of Nephila clavipes spidroin 1 known as rS1/9, and their biocompatibility and degradation behavior in vitro and in vivo. The vascularization and intergrowth of the connective tissue, which was penetrated with nerve fibers, at 8 weeks after subcutaneous implantation in Balb/c mice was more profound using the rS1/9 scaffolds. Implantation of both scaffolds into bone defects in Wistar rats accelerated repair compared to controls with no implanted scaffold at 4 weeks. Based on the number of macrophages and multinuclear giant cells in the subcutaneous area and the number of osteoclasts in the bone, regeneration was determined to be more effective after the rS1/9 scaffolds were implanted. Microscopic examination of the morphology of the matrices revealed differences in their internal microstructures. In contrast to fibroin-based scaffolds, the walls of the rS1/9 scaffolds were visibly thicker and contained specific micropores. We suggest that the porous inner structure of the rS1/9 scaffolds provided a better micro-environment for the regenerating tissue, which makes the matrices derived from the recombinant rS1/9 protein favorable candidates for future in vivo applications.

Lymph node compression of the lesser occipital nerve: a cause of migraine.

Recent investigation has focussed on the concept of peripherally triggered migraine headaches caused by compression, irritation or entrapment of the sensory nerves in the head and neck. We report a case of a 52-year-old male suffering from an occipitoparietal migraine that presented with a mass in the right occipital area. The mass was found in the deep layer of subcutaneous tissue just over the semispinalis muscle, sitting on top of the lesser occipital nerve, which was preserved through delicate dissection using loupe magnification. Histopathological findings of the mass reported benign, reactive hyperplasia of the lymph node. After removal of the mass, the patient reported complete resolution of headaches. Sensation of the scalp was not altered. This is the first report of a case of hyperplastic lymph node causing migraine through physical compression of a peripheral nerve.

The spatial and segmental innervation of somatic acupoint - a study of canine Shen-Shu point (BL-23).

Although an acupuncture needle penetrates the skin, subcutaneous tissue, and underlying muscle, the most effective locus for the somatic acupoint on the needle path is not well established. We therefore investigated the sensory innervations of tissues in the needle path of the canine Shen-Shu point and evaluated their roles in initiating an acupunctural signal. Horseradish peroxidase solution was injected at all three levels within the acupoint. Only a few peroxidase-positive neurons were observed in the L1 dorsal root ganglion following intradermal injection. Following subcutaneous injection, peroxidase-labeled neurons were detected extending from spinal levels T10 to L2, with maximal labeling at T12 (46.3%). Approximately 95% of positive neurons were at spinal levels T11, T12, T13, and L1. As a result of an intramuscular injection, labeled neurons were observed at spinal levels T12 to L3, with most labeling occurring at L1 (39.9%). Approximately 95% of positive neurons were at spinal levels T13, L1, and L2. The results suggest that most afferent terminals are in the subcutaneous tissue rather than the muscular tissue, with an approximate ratio of 3.75:1. The data provide solid evidence that sensory innervation to a somatic acupoint is confined to a spinal segment and spatially organized, and we speculate that to cause a maximum effect, the centripetally transmitted signal from needling a somatic acupoint is spatio-segmental and divergently amplified.

Evidence that peripheral rather than intracranial thermal signals induce thermoregulation.

Numerous effector mechanisms have been discovered, which change body temperature and thus serve to maintain the thermal integrity of homeothermic animals. These mechanisms are driven by thermal signals that are processed by neurons in the hypothalamic preoptic area. To keep a tight control over body temperature, these neurons have to receive accurate thermal information. Although in vitro studies have shown the direct thermosensitive ability of neurons in the preoptic area, other observations suggest the existence of peripheral thermosensation and an ascending thermal pathway to the thermoregulatory center. Direct evidences for either one, or both are still missing. In the present study, brain, rectal, subcutaneous and skin surface temperatures were measured during 15, 30, 60 and 120 min of cold exposure (4 degrees C) in rats and compared with neuronal activation due to cold stress shown by c-fos in situ hybridization histochemistry. Subcutaneous and skin surface temperatures dropped continuously throughout the 120 min of cold exposure by 1.4 degrees C and 6.5 degrees C, respectively. However, during the first 30 min, brain and rectal temperatures increased by 0.3 degrees C and 0.25 degrees C, respectively, and even after 60 min of cold stress, brain temperature did not decrease under the level measured at 0 min. Since the brain temperature did not decrease, it is unlikely that intracranial thermoreceptors are involved in the transmission of "cold" thermal signal to induce thermoregulation. At 30 min of cold exposure, neurons in all known thermoregulatory areas (like the ventrolateral part of the medial preoptic nucleus, the lateral retrochiasmatic area, the lateral parabrachial nucleus and the peritrigeminal nucleus) were already maximally activated. These observations clearly indicate that the activation of neurons in the preoptic and several other thermoregulatory nuclei is induced in vivo by thermal signals originating in the periphery, and not in the CNS.

Temporal summation of pain evoked by mechanical stimulation in deep and superficial tissue.

UNLABELLED: Temporal summation of deep tissue pain has been suggested to be facilitated in chronic musculoskeletal pain syndromes. This study aimed to test whether temporal summation of mechanical induced pressure pain is (1) more pronounced at short (1 second) interstimulus intervals (ISIs) compared with long ISI (30 seconds), (2) more potent than summation elicited by pure skin stimulation, and (3) attenuated in women compared with men. Twelve age-matched men and 12 women were included. A computer-controlled pressure stimulator with a probe surface of 1 cm2 was used to give 10 stimulations to the tibialis anterior, tibia periosteum, and the first web of the hand. Sequential stimulation at pressure pain threshold intensity was applied with different ISIs (1, 3, 5, 10, and 30 seconds). The pain intensity was assessed on a visual analog scale (VAS) after each individual stimulus. The VAS scores after the 10th stimulation with 1-second ISI were increased (P < .05) by 418% +/- 77%, 378% +/- 89%, and 234% +/- 66% compared with the first stimulation for tibia, tibialis anterior, and web, respectively. Temporal summation of pain was observed for all ISIs in tibialis anterior and tibia, eg, 30-second ISI evoked a VAS increase of 192% +/- 71 % (tibia) and 117% +/- 42% (tibialis anterior) compared with the first stimulation. The VAS score after the 10th web stimulation was smaller (P < .05) than that of the 10th tibialis anterior or tibia stimulation. A regression analysis between stimulation number and VAS score showed that the pain intensity increased progressively (1) more for 1-second ISIs compared with longer ISIs (P < .01) and (2) faster in deep tissue compared with skin (P < .01). No gender difference was observed. The temporal summation might be related to both central and peripheral mechanisms. PERSPECTIVE: Pain originating in deep tissue influences central pain processing systems more than superficial tissue. This might be of importance in patients with musculoskeletal pain.

Plexiform vascular structures in the human digital dermal layer: a SEM--corrosion casting morphological study.

This study aimed to describe the impressive diversity of vascular plexiform structures of the hypodermal layer of human skin. We chose the human body site with the highest concentration of dermal corpuscles, the human digit, and processed it with the corrosion casting technique and scanning electron microscopy analysis (SEM). This approach proved to be the best tool to study these microvascular architectures, free from any interference by surrounding tissues. We took high-definition pictures of the vascular network of sweat glands, thermoreceptorial and tactile corpuscles, the vessels constituting the glomic bodies and those feeding the hair follicles. We observed that the three-dimensional disposition of these vessels strictly depends on the shape of the corpuscles supplied. We could see the tubular vascularization of the excretory duct of sweat glands and the ovoid one feeding their bodies, sometimes made up of two lobes. In some cases, knowledge of these morphological data regarding the normal disposition in space and intrinsic vascularization structure of the dermal corpuscles can help to explain many of the physiopathological changes occurring during chronic microangiopathic diseases.

[Microanatomy study of facial nerve distribution at the temporal region for safe facelifting].

OBJECTIVE: To investigate the route and scope of the facial nerve in the temporal region for clinical applications. METHODS: Temporal region dissection was performed on 12 cadavers (24 sides) under light microscope. RESULTS: There are two branches of the facial nerve in the temporal region from the superior margin of the parotid: the temporal branch and the zygomatic branch. Each of them has two to five branches, which run in the deep layer of the superficial temporal fascia. The temporal branch crosses the zygomatic arch to the temporal region, innervating the frontal muscle, the orbicularis oculi muscle, the corrugator supercilii muscle, and the muscle surrounding the ear, etc. The zygomatic branch goes to the lateral canthus, innervating the orbicularis oculi muscle, the upper and lower eyelid and zygomatic muscles. There are communicating branches among the temporal branches, the zygomatic branches and the supraorbital and lacrimal nerves of the ophthalmic nerve. CONCLUSION: The temporal branches and zygomatic branches of the facial nerve run between the deep zone of the superficial temporal fascia and the superficial layer of the profound temporal fascia, where dissection should be avoided during rhytidectomy in order not to damage the facial nerve branches.