Population risk factors for nulliparous, term, singleton, vertex caesarean birth: a national cross-sectional study.

OBJECTIVE: To characterise medical, obstetric and demographic risk factors associated with nulliparous, term, singleton, vertex (NTSV) caesarean birth. STUDY DESIGN: Cross-sectional study. SETTING: United States delivery hospitalisations. POPULATION: NTSV births in 2016-18 US natality data. METHODS: This study analysed a national sample of natality data generated by the United States National Vital Statistics System. NTSV deliveries were identified. The primary outcome was caesarean birth. Risk factors including maternal age, body mass index (BMI) and pregestational diabetes were analysed. Multivariable log-linear regression models analysed factors associated with NTSV caesarean with adjusted risk ratios (aRR) as measures of effect. RESULTS: Of 11 622 400 deliveries, 3 764 707 met NTSV criteria, and their caesarean section rate was 25.9%. Maternal age 35-39 years (aRR 1.51, 95% CI 1.50-1.52) and 40-54 years (aRR 2.03, 95% 2.00-2.05) compared with age 19-34 years; BMI 25 to <30 kg/m2 (aRR 1.32, 95% CI 1.31-1.33), 30 to <35 kg/m2 (aRR 1.57 95% CI 1.56-1.58), 35 to <40 kg/m2 (aRR 1.82, 95% CI 1.80-1.83) and ≥40 kg/m2 (aRR 2.17, 95% CI 2.15-2.19) compared with BMI 18.5-24.9 kg/m2; and pregestational diabetes (aRR 1.54, 95% CI 1.51-1.57) were all associated with increased risk. Risk factors allowed stratification of patients into high-risk versus low-risk groups. The NTSV caesarean rate was 37.9% in women who had one or more of the following characteristics: age ≥35 years, BMI ≥30 kg/m2 or pregestational diabetes. In comparison, the NTSV caesarean rate was 20.8% among women without any of these three risk factors (P < 0.01). CONCLUSION: Among NTSV births, BMI, maternal age and medical conditions are important risk factors for caesarean delivery.

Evaluation of fracture resistance of ceramic veneers with different preparation designs and loading conditions: An in vitro study.

PURPOSE: The purpose of this study was to evaluate the effect of incisal butt joint and incisal overlap design on the fracture resistance of ceramic veneers under two different loading conditions, i.e., 125° and 60° representing protrusive and intercuspal movements, respectively. MATERIALS AND METHODS: Thirty-two maxillary central incisors were divided into two groups of sixteen specimens each and were prepared with incisal butt joint and incisal overlap design. Ceramic veneers were fabricated and cemented. Both the groups were further divided and mechanical testing to evaluate the fracture resistance were done using the universal testing machine. The values were recorded in Newton along with the assessment of the failure mode of both veneer and the tooth. RESULTS: Unpaired t-test showed a significant difference (P < 0.05) with butt joint design having higher fracture resistance than palatal overlap design with the mean value of 409.50N at 60° angle and 473.37N at 125° angle. Paired t-test depicted a significant difference for both the designs at 125° than at 60° angle (P < 0.05). Chi-square analysis showed more number of intact veneers with butt joint design; however, there was no significant difference (P > 0.05). Failure mode of teeth showed more number of coronal fracture followed by cervical fracture and root fracture, but there was no significant difference between the two groups (P > 0.05). CONCLUSION: Butt joint design had higher fracture resistance than palatal overlap design. Under functional loads for both designs, fracture resistance was higher at 125° than at 60° angle.

Ca2+-dependent protein kinases and stress signal transduction in plants.

Stress responses in plants involve changes in the transcription of specific genes. The constitutively active mutants of two related Ca2+-dependent protein kinases (CDPK1 and CDPK1a) activate a stress-inducible promoter, bypassing stress signals. Six other plant protein kinases, including two distinct CDPKs, fail to mimic this stress signaling. The activation is abolished by a CDPK1 mutation in the kinase domain and diminished by a constitutively active protein phosphatase 2C that is capable of blocking responses to the stress hormone abscisic acid. A variety of functions are mediated by different CDPKs. CDPK1 and CDPK1a may be positive regulators controlling stress signal transduction in plants.

Radiographic diagnosis of small intestinal obstruction in pet rabbits (Oryctolagus cuniculus): 63 cases.

OBJECTIVES: To identify radiographic features that can be used to aid in the diagnosis of small intestinal obstruction in pet rabbits. MATERIALS AND METHODS: Retrospective study comparing radiographic features of 63 cases of confirmed intestinal obstruction with 50 abdominal radiographs taken of rabbits without gastrointestinal disease. Abdominal radiographs were examined for gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum. RESULTS: Gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum were all features that differed between rabbits with small intestinal obstruction and rabbits without gastrointestinal disease. Radiographic features associated with small intestinal obstruction included severe gastric dilation, gastric contents primarily consisting of liquid and gas, small intestinal dilation and absence of large amounts of gas in the caecum and large intestine. CLINICAL SIGNIFICANCE: Observation on gastric size, small intestinal dilatation and gas within the large intestine and caecum aid in radiological diagnosis of small intestinal obstruction in rabbits and so can guide appropriate treatment.

Osseous versus Nonosseous Spinal Epidural Arteriovenous Fistulas: Experiences of 13 Patients.

BACKGROUND AND PURPOSE: Spinal epidural arteriovenous fistulas are rare vascular malformations. We present 13 patients with spinal epidural arteriovenous fistulas, noting the various presenting symptom patterns, imaging findings related to bone involvement, and outcomes. MATERIALS AND METHODS: Among 111 patients with spinal vascular malformations in the institutional data base from 1993 to 2017, thirteen patients (11.7%) had spinal epidural arteriovenous fistulas. We evaluated presenting symptoms and imaging findings, including bone involvement and mode of treatment. To assess the treatment outcome, we compared initial and follow-up clinical status using the modified Aminoff and Logue Scale of Disability and the modified Rankin Scale. RESULTS: The presenting symptoms were lower back pain (n = 2), radiculopathy (n = 5), and myelopathy (n = 7). There is overlap of symptoms in 1 patient (No. 11). Distribution of spinal epidural arteriovenous fistulas was cervical (n = 3), thoracic (n = 2), lumbar (n = 6), and sacral (n = 2). Intradural venous reflux was identified in 7 patients with congestive venous myelopathy. The fistulas were successfully treated in all patients who underwent treatment (endovascular embolization, n = 10; operation, n = 1) except 2 patients who refused treatment due to tolerable symptoms. Transarterial glue (n = 7) was used in nonosseous types; and transvenous coils (n = 3), in osseous type. After 19 months of median follow-up, the patients showed symptom improvement after treatment. CONCLUSIONS: Although presenting symptoms were diverse, myelopathy caused by intradural venous reflux was the main target of treatment. Endovascular treatment was considered via an arterial approach in nonosseous types and via a venous approach in osseous types.

Cannulation of Occluded Inferior Petrosal Sinuses for the Transvenous Embolization of Cavernous Sinus Dural Arteriovenous Fistulas: Usefulness of a Frontier-Wire Probing Technique.

BACKGROUND AND PURPOSE: Pursuing an alternative access route for transvenous embolization of cavernous sinus dural arteriovenous fistulas can be challenging in patients with an occluded inferior petrosal sinus. We found that cannulation of even a completely occluded inferior petrosal sinus is feasible, especially when using a standard hydrophilic-polymer-jacketed 0.035-inch guidewire as a frontier-wire for probing. MATERIALS AND METHODS: From 2002 to 2017, the frontier-wire technique was tried in 52 patients with occluded inferior petrosal sinuses for transvenous embolization of cavernous sinus dural arteriovenous fistulas at our center. Technical success was defined as access into the affected cavernous sinus compartment with a microcatheter through the occluded inferior petrosal sinus and deployment of at least 1 coil. The complications and treatment outcomes were analyzed. RESULTS: The frontier-wire technique was applied in 52 patients with 57 occluded inferior petrosal sinuses (52 ipsilateral and 5 contralateral inferior petrosal sinuses). Technical success rates were 80.8% (42/52) of patients and 73.7% (42/57) of inferior petrosal sinuses. Alternative transvenous routes were used in 3 patients, and transarterial access was used in 7 patients. Complete embolization of fistulas was achieved in 82.2% (37/45) of patients in the transvenous embolization group and in 14.3% (1/7) of patients in the transarterial group. No procedure-related morbidity or mortality was observed. CONCLUSIONS: Transvenous embolization of cavernous sinus dural arteriovenous fistulas, even through a completely occluded inferior petrosal sinus, is feasible. The difficulty of passing the microcatheter can be minimized by prior probing of the occluded inferior petrosal sinus using a standard 0.035-inch guidewire; the trace of the guidewire on the roadmap image serves as a guide for microcatheter navigation through the inferior petrosal sinus on fluoroscopy.

Engineered GFP as a vital reporter in plants.

BACKGROUND: The green-fluorescent protein (GFP) of the jellyfish Aequorea victoria has recently been used as a universal reporter in a broad range of heterologous living cells and organisms. Although successful in some plant transient expression assays based on strong promoters or high copy number viral vectors, further improvement of expression efficiency and fluorescent intensity are required for GFP to be useful as a marker in intact plants. Here, we report that an extensively modified GFP is a versatile and sensitive reporter in a variety of living plant cells and in transgenic plants. RESULTS: We show that a re-engineered GFP gene sequence, with the favored codons of highly expressed human proteins, gives 20-fold higher GFP expression in maize leaf cells than the original jellyfish GFP sequence. When combined with a mutation in the chromophore, the replacement of the serine at position 65 with a threonine, the new GFP sequence gives more than 100-fold brighter fluorescent signals upon excitation with 490 nm (blue) light, and swifter chromophore formation. We also show that this modified GFP has a broad use in various transient expression systems, and allows the easy detection of weak promoter activity, visualization of protein targeting into the nucleus and various plastids, and analysis of signal transduction pathways in living single cells and in transgenic plants. CONCLUSIONS: The modified GFP is a simple and economical new tool for the direct visualization of promoter activities with a broad range of strength and cell specificity. It can be used to measure dynamic responses of signal transduction pathways, transfection efficiency, and subcellular localization of chimeric proteins, and should be suitable for many other applications in genetically modified living cells and tissues of higher plants. The data also suggest that the codon usage effect might be universal, allowing the design of recombinant proteins with high expression efficiency in evolutionarily distant species such as humans and maize.

Sugars as signaling molecules.

Recent studies indicate that, in a manner similar to classical plant hormones, sugars can act as signaling molecules that control gene expression and developmental processes in plants. Crucial evidence includes uncoupling glucose signaling from its metabolism, identification of glucose sensors, and isolation and characterization of mutants and other regulatory components in plant sugar signal transduction pathways. The emerging scenario points to the existence of a complex signaling network that interconnects transduction pathways from sugars and other hormone and nutrient signals.

Plant mitogen-activated protein kinase signaling cascades.

Mitogen-activated protein kinase (MAPK) cascades have emerged as a universal signal transduction mechanism that connects diverse receptors/sensors to cellular and nuclear responses in eukaryotes. Recent studies in plants indicate that MAPK cascades are vital to fundamental physiological functions involved in hormonal responses, cell cycle regulation, abiotic stress signaling, and defense mechanisms. New findings have revealed the complexity and redundancy of the signaling components, the antagonistic nature of distinct pathways, and the use of both positive and negative regulatory mechanisms.

cDNA cloning and prokaryotic expression of maize calcium-dependent protein kinases.

Using degenerate oligonucleotide primers corresponding to conserved regions of the calcium-dependent protein kinase (CDPK) family, we carried out a polymerase chain reaction and obtained four distinct partial-length cDNAs from a maize leaf library. We then used these clones as probes for conventional screening and isolated 19 longer clones from another cDNA library of maize seedlings. These clones were classified into four groups based on their DNA cross-hybridization. Two full-length cDNAs, designated as ZmCDPK9 and ZmCDPK7, were sequenced and characterized. The predicted protein of each clone was a typical CDPK with eleven canonical subdomains of protein kinases, and four EF-hand calcium-binding motifs in its N-terminal and C-terminal halves, respectively. The catalytic and regulatory domains were linked by a well-conserved junction domain. The N-terminus of the protein also contained a consensus sequence for an N-myristoylation signal. Northern blot analysis showed that the transcription level of each gene was higher in roots and etiolated leaves than in green leaves. To confirm the calcium dependency of the maize enzymes, the entire coding region of ZmCDPK9 was subcloned into an expression vector so that it was in frame with the vector-encoded peptide tags. A cell-free extract of Escherichia coli transformed with the recombinant plasmid exhibited calcium-dependent phosphorylation activity, using casein as a substrate.

A simple phase-extraction assay for chloramphenicol acyltransferase activity.

A simple and convenient phase extraction assay for chloramphenicol (Cm) acetyltransferase (CAT) activity has been developed, based on the enzymatic butyrylation of radiolabelled Cm. The assay is linear over two to three orders of magnitude of enzyme concentration, is highly sensitive, and substantially less expensive than all presently available alternatives. Methods for convenient CAT assay, adapted for mammalian cells, plant protoplasts, and mammalian cell culture supernatants, are described. These methods should also simplify measurement of CAT activity in other organisms, such as yeast and bacteria. In addition, a simple pre-extraction procedure is presented for purifying radiolabelled Cm which allows a 25-fold increase in sensitivity using tritiated substrates.

Molecular identification of phenylalanine ammonia-lyase as a substrate of a specific constitutively active Arabidopsis CDPK expressed in maize protoplasts.

Phenylalanine ammonia-lyase (PAL) is a key enzyme in pathogen defence, stress response and secondary metabolism and is subject to post-translational phosphorylation. In order to address the significance of this phenomenon it is necessary to identify the protein kinase (PK) responsible and place it in its regulatory circuit. Using protoplast transient expression of Arabidopsis kinase genes coupled to immunocomplex kinase assay, it has been possible to screen for specific PAL kinase. We show here that AtCPK1 (calcium dependent PK), but not other closely related PKs could phosphorylate both a recombinant PAL protein and a peptide (SRVAKTRTLTTA) that is a site phosphorylated in vivo. Identification of the specific CDPK as a PAL kinase now opens up the possibility of exploring the calcium link in biotic stress signalling, salicylate and phytoalexin production as well as the significance of PAL phosphorylation. The protoplast transient expression system is a potentially powerful method to determine and screen for plant gene functions utilising genomic and proteomic data.

Structural analysis of chromophore-labeled disaccharides by capillary electrophoresis tandem mass spectrometry using ion trap mass spectrometry.

Disaccharides tagged with p-aminobenzoic acid (ABA) were separated by capillary electrophoresis (CE) and analyzed on-line with negative ion electrospray ionization tandem mass spectrometry (ESI/MS/MS). The formation of glycosylamine instead of reductive amination was selected as the derivatization reaction. In negative ion ESI, the glycosylamine approach provides more information on linkage and anomeric configuration than reductive amination. In CE analysis of ABA-labeled disaccharides, alpha-cyclodextrin (CD) was found to play a crucial role in the separation of linkage isomers. Although ammonium acetate/alpha-CD provided the best resolution of linkage isomers, the borate buffer was superior to alpha-CD in the separation of disaccharides with the same linkage but different anomeric configuration and/or monosaccharide composition. Both alpha-CD and borate suppressed the ion signal in ESI, and operational conditions were successfully obtained using 10 mM alpha-CD or 10 mM borate.

Spreader graft: a method of reconstructing the roof of the middle nasal vault following rhinoplasty.

Submucosal placement of strips of cartilage along the anterior border of the septum--the spreader graft--has proved to be an effective method for reconstructing the roof of the middle vault. It is recommended in all primary rhinoplasty patients in whom resection of the roof of the upper cartilaginous vault is a necessary part of the surgical plan.

Secondary rhinoplasty.

Secondary rhinoplasty is a highly complex, judgmental type of surgery. It is only through analysis of the successful treatment of various problems in secondary rhinoplasty that meaningful information can be obtained.

Rhinoplasty: personal evolution and milestones.

Over the past 35 years, aesthetic rhinoplasty has evolved from a generic, reductive operation to a highly individualized, problem-specific operation that often combines augmentation with reduction. The author's experience has been marked by the following conceptual and technical milestones that have contributed to an ongoing exploration and advancement of nasal surgery: (1) vestibular stenosis: diagnosis of a surgical consequence; (2) etiology and treatment of supratip deformity: the dynamic relationship of soft-tissue contour to skeleton; (3) etiology and treatment of the tip with inadequate projection: tip graft design; (4) practical aesthetics of balance: the augmentation-reduction approach to rhinoplasty; (5) support of the middle vault: functional and aesthetic effects; (6) malposition of the lateral crura: recognition and management; and (7) the significance of the middle crura: clinical and aesthetic considerations.

Tip graft: a 20-year retrospective.

This paper chronicles a personal experience with nasal tip grafts over 20 years. In the first period (1968-1975), the original graft was designed for use in secondary rhinoplasty cases to obtain both projection of the tip and increased angulation at the columellar-lobular junction. The use was soon expanded to primary patients with inadequate tip projection. During the middle period (1975-1982), the applications for tip grafting were expanded to include many kinds of tip problems (both primary and secondary), cleft lip noses, and various ethnic noses, especially those with thick skin. The incidence of postoperative displacement and/or visibility of the graft was reduced as multiple grafts of solid, bruised, and crushed cartilage became routine. Ear cartilage was first used and ethmoid was abandoned as a primary graft. The incidence of infection was significantly reduced. The current period (1982-1991) is marked by refinements in technique and materials. Greater versatility with graft composition and materials makes possible a variety of tip configurations, custom-made for individual requirements.

Tarsal fixation in lower blepharoplasty.

Proceeding from the premise that a "youthful" eyelid has a pretarsal bulge while a "senile" eyelid has a pretarsal flatness, the tarsal fixation technique for lower blepharoplasty has been introduced--to reposition part of the orbicularis in front of the tarsus to produce a pretarsal bulge. The technique is presented as a suggested adjunct to the usual types of lower blepharoplasty.

A change in the technique of supratarsal fixation in upper blepharoplasty.

Fixation of the orbicularis muscle to the levator muscle in an upper blepharoplasty can create a higher supratarsal fold in selected caucasians. The technique that I introduced two years ago has been refined to eliminate one of the major problems (postoperative morbidity).

The expert teaching system: a new method for learning rhinoplasty using interactive computer graphics.

We have developed software that employs interactive computer graphics to simulate the surgical experience of rhinoplasty by allowing the surgeon to experiment within a model of nasal behavior. For any of three preoperative noses, the surgeon can choose and see the effects of dorsal resection, modification of nasal spine or caudal septum, alar cartilage resection, osteotomy, alar wedge resection, and a variety of nasal grafts. The available choices and views total nearly 3000 images, or approximately 200 different surgical solutions. The surgeon can get textual analysis at any time or see accelerated healing to the projected nasal appearance at 1 year. We believe that the ability to experiment without risk, to safely learn the biological laws governing nasal behavior, should augment the development of surgical judgement in rhinoplasty.