Normal embryonic development of the greater horseshoe bat Rhinolophus ferrumequinum,with special reference to nose leaf formation

The order Chiroptera (bats) is the second largest group of mammals, composed of more than 1,300 species. Although powered flight and echolocation in bats have attracted many biologists, diversity in bat facial morphology has been almost neglected. Some bat species have a “nose leaf,” a leaf-like epithelial appendage around their nostrils. The nose leaf appears to have been acquired at least three times independently in bat evolution, and its morphology is highly diverse among bats species. Internal tissue morphology of nose-leaves has been investigated through histological analyses of late-stage fetuses of some bat species possessing the nose leaf. However, the proximate factors that bring about chiropteran nose-leaves have not been identified. As an initial step to address the question above, we describe the normal embryonic development of the greater horseshoe bat Rhinolophus ferrumequinum, and examine development of the tissues associated with their nose leaf during embryogenesis through histological analyses. We found that the nose leaf of R. ferrumequinum is formed through two phases. First, the primordium of the nose leaf appears as two tissue bulges aligned top and bottom on the face at embryonic stages 15–16. Second, the sub-regions of the nose leaf are differentiated through ingrowth as well as outgrowth of the epithelium at stage 17. In embryogenesis of Carollia perspicillata, a phyllostomid species with a nose leaf, the nose leaf primordium is formed as a small tissue bulge on the nostril at stage 17. This tissue bulge grows into a dorsally projected thin epithelial structure. Such differences in the nose leaf developmental process between chiropteran lineages may suggest that distinct developmental mechanisms have been employed in each lineage's nose leaf evolution.     

Role of the nose in resistive load detection

Previous resistive load detection (RLD) studies have ignored the nose, the usual route of breathing. Weber's law predicts the delta R50 (the added load detectable on 50% of presentations) to be a fixed percent of the background resistance (R0) and thus the delta R50/R0 ratio (the Weber fraction) is constant. We have noted the nose to be sensitive to added load, we wondered if the nose might play a role in RLD. To determine whether this was true and to characterize the effects of changes in R0 in the range of normal nasal resistance (RN), we determined R0 and delta R50 using standard techniques under the following conditions: nose vs. decongested nose, nose vs. nose with added external R0 (3.0 and 8.0 cmH2O X l-1 X s), nose vs. anesthetized nose, nose vs. mouth, and mouth vs. mouth with added load (3 cmH2O X l-1 X s). We found that decongestant decreased RN [4.3 +/- 0.6 (SE) to 3.1 +/- 0.5 cmH2O X l-1 X s, P less than 0.05] and delta R50 (1.7 +/- 0.5 to 1.1 +/- 0.3 cmH2O X l-1 X s, P less than 0.05). When an external load of 3 cmH2O X l-1 X s was added to the nose, delta R50 did not change significantly (1.4 +/- 0.2 to 1.1 +/- 0.2 cmH2O X l-1 X s), but the Weber fraction decreased (0.28 +/- 0.05 to 0.15 +/- 0.03, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Respiratory volume perception through the nose and mouth determined noninvasively

The relative importance of the nose vs. the mouth in the perception of respiratory volumes has never been assessed, nor have previous respiratory perception studies been performed noninvasively. Using respiratory inductive plethysmography, we monitored 12 normal subjects noninvasively when breathing either exclusively through the nose or mouth. The sensation of inspired volume mouth breathing was compared with that of nose breathing over a wide range of the inspiratory capacity. The psychophysical techniques of tidal volume duplication, tidal volume doubling, and magnitude estimation were utilized. A just noticeable difference was calculated from the constant error of the tidal volume duplication trials. The exponents for magnitude estimation were 1.06 and 1.07 for nose and mouth breathing, respectively. The other psychophysical techniques also revealed no differences in nose and mouth volume perception. These results suggest that tidal volume changes are perceived equally well through the nose and mouth. Furthermore, the location of the receptors, important in volume perception, is probably at a distal point common to the nose and mouth.     

Morphologic and genetic studies of the nose

The aim of this paper is to find metrical and morphological shape variants of the nose, which are highly determined by heredity. For this, 67 monozygotic and 59 dizygotic twins were measured and the morphological details of the nasal region were recorded and documented by taking photographs in the three standard views of the nose. The study of shape variants in our population was based on 160 control persons, who were not related. Out of this group 61 control pairs were put together by random selection with regard to sex and age. From every examined person data of 9 metrical and 43 well distinguishable morphological variants of the nose were gathered. They had been worked out of numerous observable forms. It could be shown that two measures (breadth of the nose, breadth of the tip of the nose) and eight other morphological features of the nose are of good heredity.     

The axial frontonasal flap revisited

After 15 years of experience and 50 cases, we think that the axial frontonasal flap is of great value for the repair of large skin defects of the nose. This flap mobilizes all the skin cover of the nose located above the defect and the adjacent frontal skin and rotates it on a vascular pedicle existing at the level of the inner canthi. The excess of skin of the glabella is then transferred to the nose, and this large flap allows coverage of the defect without tension or distortion. The long-term results are very good, with a hardly visible repair in 26 of 50 patients, the long scar being very well hidden at the periphery of the nose.     

Family resemblance for cranio-facial measurements in Velanti Brahmins from Andhra Pradesh, India

Maximum likelihood estimates of familial correlations are presented for 12 cranio-facial measurements taken on 399 nuclear families from Southern India. Marital resemblance is significantly different from zero for head circumference, head breadth, minimum frontal breadth, bizygomatic breadth, total facial height, and nasal height, but not for bigonial breadth, nose breadth, nose depth, or ear dimensions. All other familial correlations are significantly greater than zero except for the father-daughter correlation for nasal depth. Path analysis with a TAU transmission model with sex effects reveals that family resemblance for head circumference, head length, bigonial breadth, total facial height, and nasal height, but not for bigonial breadth, nose breadth, nose depth, or ear dimensions. All other familial correlations are significantly greater than zero except for the father-daughter correlation for nasal depth. Path analysis with a TAU transmission model with sex effects breadth, and sex effects in transmission were found for head breadth and nose dimensions. Sex effects in this sample may be due to the fact that different anthropometrists were used for male and female subjects.     

Sniffing and spatiotemporal coding in olfaction

The act of sniffing increases the air velocity and changes the duration of airflow in the nose. It is not yet clear how these changes interact with the intrinsic timing within the olfactory bulb, but this is a matter of current research activity. An action of sniffing in generating a high velocity that alters the sorption of odorants onto the lining of the nasal cavity is expected from the established work on odorant properties and sorption in the frog nose. Recent work indicates that the receptor properties in the olfactory epithelium and olfactory bulb are correlated with the receptor gene expression zones. The responses in both the epithelium and the olfactory bulb are predictable to a considerable extent by the hydrophobicity of odorants. Furthermore, receptor expression in both rodent and salamander nose interacts with the shapes of the nasal cavity to place the receptor sensitivity to odorants in optimal places according to the aerodynamic properties of the nose.     

Lengthening the aesthetically short nose

An aesthetically short nose is defined as a developmental deformity in which the nose appears foreshortened. It is characterized by a decreased distance from the nasofrontal angle (NFA) to the tip-defining points (TDP) and an increased nasolabial angle with increased nostril show. A method is described and illustrated for lengthening the aesthetically short nose by rotating the nasal tip in an inferior direction. This rotation results in an actual lengthening, as well as an illusion of lengthening of the nose.     

Lateral facilitation between primary mechanosensory neurons controls nose touch perception in C. elegans

The nematode C. elegans senses head and nose touch using multiple classes of mechanoreceptor neurons that are electrically coupled through a network of gap junctions. Using in?vivo neuroimaging, we have found that multidendritic nociceptors in the head respond to harsh touch throughout their receptive field but respond to gentle touch only at the tip of the nose. Whereas the harsh touch response depends solely on cell-autonomous mechanosensory channels, gentle nose touch responses require facilitation by additional nose touch mechanoreceptors, which couple electrically to the nociceptors in a hub-and-spoke gap junction network. Conversely, nociceptor activity indirectly facilitates activation of the nose touch neurons, demonstrating that information flow across the network is bidirectional. Thus, a simple gap-junction circuit acts as a coincidence detector that allows primary sensory neurons to integrate information from neighboring mechanoreceptors and generate somatosensory perception.     

Lengthening of the postoperative short nose: combined use of a gull-wing concha composite graft and a rib costochondral dorsal onlay graft

Several causes of short nose are known: congenital anomaly, developmental problem, trauma, and various types of rhinoplasty-the postoperative short nose being one of the most difficult problems to correct in plastic surgery. Contracted skin envelope, tissue deficiency of cartilage and mucosal lining, and poor circulation make postoperative short nose difficult to lengthen and susceptible to recurrence. Thus, for effective lengthening and long-term maintenance of it, specific grafts should be used to supplement the missing lining and cartilage and a mechanical support also is needed to withstand the skin contraction. The nose consists of three structural layers: the outer skin envelope, middle osteocartilaginous framework, and inner mucosal lining. Many methods have been proposed to correct short nose deformity. Those procedures lengthen the nose slightly, but none of them take into account the unique characteristics of postoperative causes and the structural concept of the nose. The procedures have resulted in only limited success. On the basis of the above clinical findings and the structural concept, we developed a surgical technique to correct postoperative short nose according to the structural layers. Our method consists of three main surgical maneuvers: (1) a gull-wing concha chondrocutaneous composite graft to supplement the deficient middle and inner layers, (2) a rib costochondral onlay graft on the dorsum to reinforce the framework, and (3) wide dissection of the outer skin envelope to cover the lengthened framework without tension. We prefer a closed surgical approach rather than an open approach to avoid too much tension on the columellar incision site and to allay patients' fear of an additional scar. From 1988 to 1998, we performed our lengthening technique on six female patients. All six patients demonstrated a significant lengthening and improved appearance postoperatively. After the lengthening procedure, the average nasolabial angle improved from 116 degrees to 104 degrees. The mean follow-up period was 8.7 months, with a range of 3 to 17 months. Sometimes, epidermal sloughing in the vertical strut of the gull-wing     

Nasal flow-resistive responses to challenge with cold dry air.

Recent studies have suggested that the inhalation of cold air through the nose is associated with the subsequent release of mediators of immediate hypersensitivity. To determine if mucosal surface heat and water loss influence the nasal functional response to cold air, we measured nasal resistance by posterior rhinomanometry before and 1, 5, and 10 min after a 4-min period of isocapnic hyperventilation (30 l/min) through the nose in nine healthy subjects (5 males, 4 females; aged 25-39 yr) while they inhaled air at 0 degrees C. During the challenge period, the subjects breathed either in and out of the nose or in through the nose and out through the mouth. No changes in nasal resistance developed when subjects breathed exclusively through the nose; however, when subjects breathed in through the nose and out through the mouth, nasal resistance was increased 200% at 1 min (P less than 0.01) after the challenge and returned to baseline values by 10 min after cessation of the challenge. These data indicate that nasal functional responses to cold dry air are dependent on the pattern of the ventilatory challenge. If the heat given up from the nasal mucosa to the incoming air is not recovered during expiration (as is the case with inspiration through the nose and expiration through the mouth), nasal obstruction will occur. Hyperpnea of cold air, per se, does not influence nasal resistance.     

An alternate strategy for reducing the large nasal base

The position of the dorsum directly influences the apparent size of the nasal base: the higher the bridge, the smaller the nasal base seems. This powerful optical illusion provides the surgeon with an alternate strategy for creating harmony in the nose with a low, straight dorsum and a disproportionately large nasal base. Instead of reducing the lower nose, the surgeon can augment the upper nose (and make whatever nasal base changes are independently necessary). This alternate strategy limits the amount of nasal skeletal reduction necessary, thereby limiting the potential for postoperative change and soft-tissue distortion and directly increasing the surgeon's control over the result.     

Monitoring growth of the methanogenic archaea Methanobacterium formicicum using an electronic nose

Growth of the methanogenic archaea, Methanobacterium formicicum, in pure culture was monitored by analysing samples from the gas phase with an array of chemical gas sensors (an `electronic nose'). Analyses of the methane and protein formation rates were used as independent parameters of growth, and the data obtained from the electronic nose were evaluated using principal component analysis (PCA). We found that different growth phases can be distinguished with the electronic nose followed by PCA evaluation. The fast response of the sensors in combination with the high correlations with other parameters measuring growth show that the electronic nose can be a useful tool to rapidly determine methanogenic growth.     

Air entry in infant resuscitation: oral or nasal routes?

Wilson-Davis, S. L., S. L. Tonkin, and T. R. Gunn. Air entry in infant resuscitation: oral ornasal routes?. J. Appl. Physiol.82(1): 152-155, 1997.The current recommendation for resuscitation of infants is to blow air into both the nose and mouth.We have observed that mothers cannot cover both the nose and mouth oftheir infants. We compared postmortem tracheal and esophageal air entryby using the nose, combined nose and mouth, and mouth routes in eightinfants. Air entry into the trachea occurred at lower pressures(P < 0.05) via a nose mask than via a combined nose and mouth mask or via a mouth mask. Air entry into thetrachea occurred at lower pressures (P < 0.05) via the nose route in the neutral and extended neck positionscompared with the flexed position. We were unable to demonstrate aneffect of the route of air entry on esophageal air entry. The findings indicate that the nasal route of air entry is more effective than thecombined nose and mouth or mouth routes and that neck flexion impedesair entry. We recommend that parents are taught to blow air into theirinfants' noses if the infant stops breathing.

     

PHYSIOLOGIC BASIS OF NASAL OPERATIONS

To be successful, intranasal operations must be so designed as to restore the normal physiologic function of the nose. It is impossible with impunity to operate upon the interior of the nose as though it were simply an air flue and on the sinuses as though they were boxes.     

A clinical definition of an ideal nasal radix

The authors developed a system of simple soft-tissue measurements to define the ideal proportions of the nose. These measurements provide the surgeon the parameters to assess when a nose is "balanced" and to define when the radix should be raised or lowered. A ratio of 2:1:1:0.75 for length, projection, height, and radix, respectively, defines the ideally balanced Caucasian nose.     

In search of the ideal nose

The proportions of the so-called ideal nasal shape and the operations designed to achieve this have been the subject of innumerable papers. The vast majority of patients in the authors' practices desire a more refined version of the nose and do not want the so-called nosejob look with ideal proportions. A total of 2930 cosmetic rhinoplasties performed over the past 20 years, based on the philosophy of refining the more unrefined features of the nose according to the patients' wishes, have been reviewed, and almost all of these patients were satisfied with the long-term shape of their nose, even though in many cases these noses would be considered less than ideal by some of the newer criteria.     

Nasal reconstruction using both cranial bone and ear cartilage

In this article, an anatomic reconstruction is described using cranial bone graft for the bony part of the nose while reconstructing the cartilaginous part with ear cartilage. This modification provides protection of the nose from the traumatic forces creating a flexible nasal tip. A modification is described and compared with the nasal reconstruction by calvarial bone itself.     

Recent advances in the development of bioelectronic nose

The olfactory system has the ability to discriminate and identify thousands of odorant compounds at very low concentrations. Recently, many researchers have been trying to develop artificial sensing devices that are based on the olfactory system. A bioelectronic nose, which uses olfactory receptors (ORs) as sensing elements, would benefit naturally optimized molecular recognition. Accordingly, ORs can be effectively used as a biological element in bioelectronic noses. Bioelectronic nose can be classified into cell-based and protein-based biosensors. The cell-based biosensor uses living cells that express olfactory receptors as the biological sensing elements and the protein-based biosensor uses the olfactory receptor protein. The binding of odorant molecules to the ORs can be measured using various methods such as piezoelectric, optic, and electric devices. Thus, bioelectronic nose can be developed by combining the biological sensing elements with these non-biological devices. The application of bioelectronic nose in a wide range of different scientific and medical fields is essentially dependent on the development of highly sensitive and selective biosensors. These sensor systems for the rapid detection of specific odorants are crucial for environmental monitoring, anti-bioterrorism, disease diagnostics, and food safety. In this article, we reviewed recent advances in the development of bioelectronic nose.