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PubMed2000

In vitro organogenesis of pancreas in Xenopus laevis dorsal lips treated with retinoic acid.

Dorsal lips of Xenopus laevis may differentiate into pancreas after treatment with retinoic acid in vitro. The dorsal lip region is fated to be dorsal mesoderm and anterior endoderm. Dorsal lip cells isolated from stage 10 early gastrula differentiate into tissues such as notochord, muscle and pharynx. However, in the present study, dorsal lips treated with 10(-4) M retinoic acid for 3 h differentiated into pancreas-like structures accompanied by notochord and thick endodermal epithelium. Sections of the explants showed that some cells gathered and formed an acinus-like structure as observed under microscopes. In addition to the morphological changes, expressions of the pancreas-specific molecular markers, XIHbox8 and insulin, were induced in retinoic acid-treated dorsal lip explants. Therefore, it is suggested that retinoic acid may induce the dorsal lip cells to differentiate into a functional pancreas. However, continuous treatment with retinoic acid did not induce pancreas differentiation at any concentration. Dorsal lips treated with retinoic acid within 5 h after isolation differentiated into pancreas-like cells, while those treated after 15 h or more did not. The present study provided a suitable test system for analyzing pancreas differentiation in early vertebrate development.

Animals↗
PubMed2004

Lip anatomy and its implications for the pollination mechanisms of Bulbophyllum species (Orchidaceae).

BACKGROUND AND AIMS: The lip structure of six Brazilian and one Asiatic species of Bulbophyllum with wind-assisted fly pollination (B. involutum, B. ipanemense and B. weddellii) and non-wind-assisted fly pollination (B. epiphytum, B. glutinosum, B. regnellii and B. rothschildianum) was studied to investigate the presence of secretory tissues related to these pollination mechanisms. METHODS: The lip study was carried out through scanning electron microscopy (lip surface) and light microscopy (anatomical features). KEY RESULTS: In most of the species studied, the osmophores (odour glands) were located in the lobes and in the upper surface of the lip callus. Differences in the lip structure were observed between the two groups (the presence of a nectary and the extent of osmophore surface), depending on the mechanism of pollination. Nectaries were found in the cavity callus in B. ipanemense, B. involutum and B. weddellii, even though their pollinators were presumably attracted by the instinct to oviposit. CONCLUSIONS: These findings corroborate the hypothesis that, because pollination in these species is dependent on an unpredictable external factor (wind), nectar is necessary to keep the insect in the flower for a long period. Despite the occurrence of a liquid-like nectar in the flowers of B. epiphytum, B. glutinosum, B. regnelli and B. rothschildianum, no anatomical evidence for nectaries was found in the lips of these species, although a similar structure may occur in another region of the flowers. This observation agrees with the fact that pollination by lip movement in the latter species requires only gravity, with no additional mechanism being needed to keep the flies in the flower.

Flowers↗
PubMed1997

Cloning and overexpression of two cDNAs encoding the low-CO2-inducible chloroplast envelope protein LIP-36 from Chlamydomonas reinhardtii.

Chlamydomonas reinhardtii, a unicellular green alga, grows photoautotrophically at very low concentrations of inorganic carbon due to the presence of an inducible CO2-concentrating mechanism. During the induction of the CO2-concentrating mechanism at low-CO2 growth conditions, at least five polypeptides that are either absent or present in low amounts in cells grown on high-CO2 concentrations are induced. One of these induced polypeptides with a molecular mass of 36 kD, LIP-36, has been localized to the chloroplast envelope. The protein was purified and the partial internal amino acid sequences were obtained through lys-C digestion. Two cDNAs encoding LIP-36 have been cloned using degenerate primers based on the amino acid sequences. The two genes encoding LIP-36 are highly homologous in the coding region but are completely different in the 5'-end and 3'-end untranslated regions. The deduced protein sequences show strong homology to the mitochondrial carrier protein superfamily, suggesting that LIP-36 is a chloroplast carrier protein. The regulation of the expression of these two genes at high- and low-CO2 growth conditions is also different. Both genes were highly expressed under low-CO2 growth conditions, with the steady-state level of LIP-36 G1 mRNA more abundant. However, neither gene was expressed at high-CO2 growth conditions. The gene products of both clones expressed in Escherichia coli were recognized by an antibody raised against LIP-36, confirming that the two cDNAs indeed encode the C. reinhardtii chloroplast envelope carrier protein LIP-36.

Amino Acid Sequence↗
PubMed2000

Memory activity of LIP neurons for sequential eye movements simulated with neural networks.

Many neurons in macaque lateral intraparietal cortex (LIP) maintain elevated activity induced by visual or auditory targets during tasks in which monkeys are required to withhold one or more planned eye movements. We studied the mechanisms for such memory activity with neural network modeling. Recurrent connections among simulated LIP neurons were used to model memory responses of LIP neurons. The connection weights were computed using an optimization procedure to produce desired outputs in memory-saccade tasks. One constraint for the training process is the "single-purpose" rule, which mimics the fact that once LIP neurons hold the memory activity of a saccade, they are insensitive to further stimuli until the motor action is completed. After training, excitatory connections were developed between units with similar preferred saccade directions, while inhibitory connections were formed between units with dissimilar directions. This "push-pull" mechanism enables the network to encode the next intended eye movement and is essential for programming sequential saccades. In simulating double saccades, the push-pull connections locked the on-going activity in the network for the first saccade until the saccade was made, then a new population of units became active to prepare for the second saccade. The simulated LIP neurons exhibited sensory responses and memory activities similar to those recorded in LIP neurons. We propose that push-pull recurrent connections might be the basic structure mediating the memory activity of area LIP in planning sequential eye movements.

Animals↗
PubMed2006

Unipolar brush cells of the cerebellum are produced in the rhombic lip and migrate through developing white matter.

Unipolar brush cells (UBCs) are glutamatergic interneurons in the cerebellar cortex and dorsal cochlear nucleus. We studied the development of UBCs, using transcription factor Tbr2/Eomes as a marker for UBCs and their progenitors in embryonic and postnatal mouse cerebellum. Tbr2+ UBCs appeared to migrate out of the upper rhombic lip via two cellular streams: a dorsal pathway into developing cerebellar white matter, where the migrating cells dispersed widely before entering the internal granular layer, and a rostral pathway along the cerebellar ventricular zone toward the brainstem. Ablation of the rhombic lip in organotypic slice cultures substantially reduced the production of Tbr2+ UBCs. In coculture experiments, Tbr2+ UBCs migrated from rhombic lip explants directly into the developing white matter of adjacent cerebellar slices. The origin of Tbr2+ UBCs was confirmed by colocalization with beta-galactosidase expressed from the Math1 locus, a molecular marker of rhombic lip lineages. Moreover, the production of Tbr2+ UBCs was Math1 dependent, as Tbr2+ UBCs were severely reduced in Math1-null cerebellum. In reeler mutant mice, Tbr2+ UBCs accumulated near the rhombic lip, consistent with impaired migration through developing white matter. Our results suggest that UBCs arise from the rhombic lip and migrate via novel pathways to their final destinations in the cerebellum and dorsal cochlear nucleus. Our findings support a model of cerebellar neurogenesis, in which glutamatergic and GABAergic neurons are produced from separate progenitor pools located mainly in the rhombic lip and the cerebellar ventricular zone, respectively.

Animals↗
PubMed2005

Analysis of 109 Japanese children's lip and nose shapes using 3-dimensional digitizer.

We assessed lip and nose shapes, which played an important role in performance evaluations, before and after cleft lip and nose surgery. We used a noncontact-type semiconductor laser 3-dimensional measurement system on normal Japanese children to obtain 3-dimensional images of noses and lips, which were accurate enough to measure facial shapes. We could rotate these images on the computer, therefore we measured the following points: the distance between the peaks of the Cupid's bow and the width of the labial fissure (frontal view), and the width of the nose and the nasal tip protrusion (basal view). Lip and nose shapes were evaluated for each gender. Additionally, nasolabial angles (NLA) were measured on the lateral views of faces. We classified the morphology of the philtral columns into four types; (1) triangular type, (2) parallel type, (3) concave type, and (4) flat type. We also classified nostril shapes into four types: (1) teardrop type, (2) heart shaped type, (3) round type, and (4) triangular type. We calculated the average of the 3-dimensional coordinate values for each landmark, and created standard facial models of normal Japanese children. Moreover, we invented a new morphological evaluation method before and after cleft lip and nose surgery, using the 3-dimensional data converting and editing software. The method was more feasible to evaluate the assessment cleft lip and nose surgery, by quantifying the surface areas of right and left nostrils and the surface areas of upper and lower vermilions, even now by measuring with the eyes and comparing them.

Anthropometry↗
PubMed2006

Upper lip reconstruction with the alar crescent flap: A new approach.

PURPOSE: The alar crescent advancement flap technique has been widely used for repair of large central defects of the upper lip and base of the nose because of its 1-stage procedural simplicity and good results. Several more complicated and multiple staged procedures that respect either structure or function, often compromising one to achieve the other, have become popular and have recently taken its place. However, these procedures are more complex and in many cases require a staged approach. In this study, we present a series of 33 patients who underwent reconstruction of large upper lip defects utilizing alar crescent flaps between 1992 and 2002. PATIENTS AND METHODS: A series of 20 patients underwent reconstruction of large upper lip defects using alar crescent flaps between 1992 and 2002. Malignant etiologies were responsible for the defect in all patients. Reconstruction was performed as a 1-staged procedure in 19 cases. In 1 patient with a total upper lip defect, bilateral alar crescent flaps were used in conjunction with a cross lip flap that was later divided in a second stage procedure. RESULTS: All patients tolerated the procedure well with no major complications. Minor complications not requiring surgical intervention occurred in 5 patients. During the 12- to 60-month follow-up, all patients were found to be satisfied with the functional result. However, 7 patients underwent minor surgical procedures for esthetic improvement. There was no recurrence of disease in the 20 patients who underwent resection of malignancy. CONCLUSIONS: In these 20 cases, we have shown the utility of the alar crescent flap for varying length partial and full-thickness reconstruction of upper lip defects. This simple and straightforward technique provided good functional and esthetic results. The disadvantage of this procedure is the loss of philtral anatomic detail. Its primary advantage is that it is a single-stage procedure with a relatively low morbidity and patient inconvenience. As a single-stage technique it satisfies concerns over cost containment over more complex and staged procedures while still providing a good functional and cosmetic result. Furthermore, for those same reasons, this procedure is a good first choice in the elderly.

Adult↗
PubMed1998

The lips. Excision and repair.

Dermatologists commonly encounter lesions arising on the lips that require excision either for biopsy or treatment. Several surgical techniques used for excision and repair of the lip in the treatment of these conditions are reviewed. Topics covered include the importance of the lip, lip anatomy as it pertains to cutaneous surgery, techniques for obtaining lip anesthesia, partial-thickness and full-thickness lip excision and repair, surgical vermilionectomy, and carbon dioxide laser vermilionectomy. Emphasis will be placed on those surgical techniques that might commonly be used in a general dermatology practice.

Esthetics↗
PubMed1994

Soft tissue changes following maxillary osteotomies in cleft lip and palate and non-cleft patients.

A retrospective study of 25 patients with unilateral cleft lip and palate and 25 patients with hypoplastic maxillae without a cleft was carried out to evaluate the effects of maxillary osteotomies at the Le Fort I level on the lip and nose profile. The pre-surgical cephalometric tracing was superimposed twice on the post-surgical cephalogram, on the cranial structures and the anterior maxillary structures, for landmark movement measurement. Results showed statistically significant correlations between soft and hard tissue movement in the cleft group. On average, the ratios of horizontal nasal tip, nasal base and lip movement to underlying hard tissue movement were approximately one fourth, one half and two thirds respectively. The ratio of vertical lip to incisor movement was about one half. The correlations were less significant in the non-cleft group, only the upper lip movement showed statistically significant correlation with hard tissue movement, with a ratio of one half horizontally and one third vertically. It was concluded that in maxillary osteotomy, the cleft group showed a higher soft tissue to hard tissue movement ratio. The correlation between soft and hard tissue movements were more statistically significant in the cleft group than in the non-cleft group. However, though statistically significant, the level of correlation was not strong on an individual basis except in the horizontal lip response of the cleft group. Individual variation was wide and clinical judgement needs to be considered accordingly.

Adult↗
PubMed1998

Secondary correction of bilateral cleft lip deformity with simultaneous Abbé flap and nasal repair.

For secondary repair of a bilateral cleft lip deformity with a short columella and defective upper lip, simultaneous correction of the lip and nose is ideal. We perform a nasal repair through a bilateral reverse-U incision and columella elongation using the upper lip. An Abbé flap is then transferred to the upper lip defect. This procedure enables total reconstruction of characteristic bilateral cleft lip deformities in one stage. We have applied this method to 15 patients (9 males and 6 females) with an average age of 18.7 years. Although some patients need jaw surgery, all have been satisfied with the results.

Adolescent↗
PubMed2001

The partial-thickness cross-lip flap for correction of postoncologic surgical defects.

PURPOSE: Abbe and Estlander cross-lip flaps have been described and designed as a full-thickness flap to reconstruct a full-thickness excisional defect. Some Mohs surgical excisions and other serial excisions leave partial-thickness defects. This article reviews a series of partial-thickness cross-lip flaps, which included some orbicularis oris muscle in the vermilion region but otherwise was a subcutaneous flap. PATIENTS AND METHODS: In the last 7 years, 110 patients with lip cancer had their postsurgical defects reconstructed 24 to 72 hours after the resection. In all cases, negative margins were established by histologic evaluation or Mohs micrographic surgery. Twenty of 29 patients had Abbe- and Estlander- (lip-switch) type flaps, which were composed of a musculomucosal pedicle of 1.25 to 1.50 cm and an attached skin/subcutaneous flap trimmed to fit the defect. The remainder had full-thickness lip-switch flaps. RESULTS: There were no vascular complications in either group. Four patients had notching or trapdoor- type bulking, which were revised after 3 to 6 months. CONCLUSION: The partial-thickness cross-lip flap has the same viability as the full-thickness flap within 1 cm from the inferior border of the mandible.

Humans↗
PubMed1995

Increased prevalence of dysplastic and malignant lip lesions in renal-transplant recipients.

BACKGROUND: Renal-transplant recipients are known to have increased rates of skin cancer associated with exposure to the sun. Little is known, however, about the prevalence and histologic features of lesions of the lips in these patients, or about risk factors for such lesions. METHODS: We examined the lips of 160 renal-transplant recipients (105 men and 55 women; mean [+/- SD] age, 48 +/- 13 years) and 160 normal subjects matched with the transplant recipients for age, sex, and skin type. The mean length of time between transplantation and the examination was 69 +/- 52 months; 58 percent of the recipients had received their grafts more than 60 months earlier. RESULTS: Among the 160 renal-transplant recipients, 21 (13 percent) had leukoplakia; in 2 (1.2 percent) the leukoplakia contained squamous-cell carcinoma. In contrast, only one normal subject (0.6 percent) had leukoplakia. Histologically, 13 of the 21 leukoplakias (62 percent) in the renal-transplant recipients who underwent biopsy were dysplastic, and 2 (10 percent) contained squamous-cell carcinoma. Actinic change was evident in 91 percent of the dysplastic lesions but not in the nondysplastic lesions (P < 0.001). Exposure to the sun and smoking were risk factors for dysplastic and malignant lip lesions in the renal-transplant recipients (P < 0.001 and P = 0.003, respectively). Among these recipients, only men had dysplastic or malignant lip lesions (P = 0.006); lipstick was used frequently by 73 percent of the women. The clinical appearance of lip lesions did not predict the presence of dysplasia or cancer. CONCLUSIONS: Renal-transplant recipients have an increased prevalence of leukoplakia, dysplasia, and cancer of the lip.

Adolescent↗
PubMed2002

An anthropometric analysis of indices of severity in the unilateral cleft lip.

The aim of this study was to analyze the relationships among three key anthropometric parameters in the unilateral cleft lip to determine the correlations, if any, among these indices of severity. Using a standardized anthropometric documentation protocol, preoperative measurements of 125 unilateral cleft lips (103 complete and 22 incomplete) were performed under general anesthesia by a single surgeon at the time of primary lip repair at the age of 3 months. The following key measurements were analyzed statistically: (1) the philtral height difference (PHD) between the cleft and noncleft sides, (2) the nasal floor width difference (NFWD) between the cleft and noncleft sides, and (3) the cleft width (CW). The mean values of all three indices were greater in the complete group versus the incomplete group. These differences were statistically significant. Linear relationships were obtained between NFWD and GAP, between PHD and GAP, and between PHD and NFWD in the complete group. In contrast, the relationships between PHD and GAP, and between PHD and NFWD were nonlinear in the incomplete group. These findings suggest that there was a strong correlation between the transverse and vertical tissue deficiencies in the complete cleft lip. In incomplete clefts, however, this correlation did not exist. In other words, the incomplete cleft lip can be associated with a severely short philtrum even in the presence of a relatively mild transverse tissue deficit. Therefore, it is not necessarily easier to repair an incomplete cleft lip in terms of the correction of the vertical tissue deficiency.

Cephalometry↗
PubMed1986

Growth of the cleft lip following a triangular flap repair.

This study involves 50 children who had a triangular flap repair for unilateral cleft lip. They have been followed for 5 to 14 years by serial measurements, photographs, and clinical evaluation. During the first 5 years, the lips were designed to allow for future growth. The expected growth did not occur. During the second 5 years, the lip length was designed equal to the normal side with the belief that unequal growth does not occur. In this group, the results supported the premise that deviation from the correct lip length would now be equally divided between too long and too short. None of the entire group has a lip which started too short becoming equal or starting equal to become too long. It is the conclusion of the authors that a repaired unilateral cleft lip retains the configuration and length determined at the time of the initial repair.

Adolescent↗
PubMed2001

Reconstruction of the superior labial sulcus in secondary bilateral cleft lip deformities: an inverted U-shaped flap.

A shallow buccal sulcus deformity following bilateral cleft lip repair is not rare. A variety of techniques are described for the secondary reconstruction of a deficient sulcus. Most of these are associated with a variable amount of contraction with subsequent obliteration of the sulcus. In this article, an inverted U-shaped flap is described for the secondary reconstruction of the deficient sublabial sulcus. In these patients, mobility of the upper lip was severely restricted, so orthodontic treatment was not possible. This technique was used in nine patients whose primary cleft lip repairs were performed in different institutions. The amount of re-adhesion or contraction was negligible, because a bare surface was not left behind and skin or mucosal grafts were not used. By advancing the lateral segments of the lip medially, projection of the upper lip was increased. The procedure resulted in adequate upper lip mobility for all patients, and sufficient sulcus was maintained during 1 to 6 years of follow-up. The patients experienced no difficulty with orthodontic appliances after this reconstruction.

Adolescent↗
PubMed2005

Mulliken method of bilateral cleft lip repair: anthropometric evaluation.

BACKGROUND: Simultaneous surgical correction of bilateral cleft lip and nasal deformity is becoming more common. This is a major change from the conventional strategy of secondary nasal correction. METHODS: Thirty patients with bilateral cleft lip and nasal deformity were repaired using the Mulliken method between July of 1997 and December of 2002. This series was composed of 10 infants with bilateral complete cleft lip, 12 with bilateral incomplete cleft lip, and eight with bilateral asymmetric cleft lip, defined as complete on one side and incomplete on the other. A preoperative orthopedic appliance was employed in five infants who had severe collapse of the lateral maxillary segments. Mean age at the time of repair was 3.8 months. RESULT: Postoperative results were evaluated anthropometrically. The mean follow-up period was 3.8 years (range, 1.2 to 5.5 years). Nasal tip protrusion was low; interalar dimension was wide; columellar length was slightly short; upper cutaneous labial height was short; and vermilion-mucosal height was near normal. All anthropometric values approached controls by 5 years. CONCLUSION: Our modified Mulliken method is effective in correction of all forms of bilateral cleft lip and nasal deformity. Further evaluation is needed for possible differences in outcome based on race and age at the time of operation.

Anthropometry↗
PubMed1982

Surgical treatment of lip cancer: the long term prognosis and functional results.

This paper presents a long term review of the prognosis and surgical results in carcinoma of the lip. The results are based on the examinations of 75 patients treated at the Peter MacCallum Clinic in Melbourne followed up for a minimum of 11 years. Surgical excision is considered to be the treatment of choice for carcinoma of the lip. Radical local excision, combined with neck dissection for involved nodes, is shown to result in a good, long term prognosis. Functional and cosmetic results have been examined closely. The simple procedures of wedge excision and vermilionectomy produce a virtually normal lip. Cross lip Abbé flaps, used to reconstruct larger lip defects, are shown to provide a durable, functional lip.

Adult↗
PubMed2006

Cleft lip and palate in mice treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin: a morphological in vivo study.

It is well-known that TCDD (2,3,7,8, tetrachloridedibenzo-p-dioxin) induces cleft palates (CPs) in pregnant C57BL mice. However, it is unclear if TCDD is a possible teratogen for cleft lip. We examined maxillofacial malformations including cleft lip in three animal strains: A/J mice, C57BL/6J mice and ICR mice. The A/J mouse develops cleft lip and palate spontaneously at a 5-10% rate. TCDD was administered in olive oil on gestation day (GD) 12.5 with gastric tubes at 10 microg/kg, 20 microg/kg, or 40 microg/kg to examine the dose-response, and on a single day from GD 8.5-14.5 to examine the timing effects of TCDD administration on lip and palate formation. Furthermore, the palatal shelf movements during GD 8.5-14.5 were observed with a stereoscopic microscope. All embryos had cleft palates when the TCDD was administered just before palatogenesis (GD11.5-GD12.5). With respect to the TCDD effects, there were large differences among the strains. In the A/J mice, the difference between a lethal dose and a dose that could induce a cleft palate was close. Cleft lips were not induced, even when the TCDD was given just before labiogenesis. Morphologically, both palatal shelves contacted perfectly along their lengths, but separated and formed cleft palates. In conclusion, TCDD is a strong inducer of cleft palates, and interferes with the fusion phase of the secondary palate, but has no effect on the lip.

Abnormalities, Drug-Induced↗