Quality of Life After Lower Leg Reconstruction With the Latissimus Dorsi Free Flap in Pediatric Patients

BACKGROUND

The latissimus dorsi free flap is a widely used reconstructive technique for complex lower leg defects in the pediatric population due to its reliability and anatomical features. However, the impact of this technique on the postoperative quality of life in children and adolescents, who require appropriate lower extremity function during their developmental period, remains to be analyzed.

METHODS

Patients who underwent microsurgical lower leg reconstruction using the latissimus dorsi flap were analyzed retrospectively. The quality of life of these patients was assessed prospectively using the Lower Extremity Functional Scale (LEFS) at a minimum of 18 months after surgical reconstruction.

RESULTS

Sixteen pediatric patients who had severe lower extremity injuries and underwent latissimus dorsi free flap reconstruction met the inclusion criteria. The mean follow-up period was 33.9 months (22-64 months). Two patients experienced postoperative complications: one had partial flap necrosis and surgical site infection, while the other developed a surgical site infection. The LEFS scores ranged from 26 to 80, with a mean score of 64.6. Remarkably, 14 of 16 patients achieved LEFS scores consistent with at least the 10th percentile when compared with normative data. Patients with severe associated fractures presented with the lowest scores.

CONCLUSIONS

Based on our findings, the latissimus dorsi flap is reaffirmed to be an excellent choice for lower leg reconstruction in the pediatric population. It effectively restores the quality of life in patients who have experienced moderate to severe lower extremity injuries.

Staged Phrenic Nerve Elongation and Free Functional Gracilis Muscle Transplantation-A Possible Option for Late Reconstruction in Chronic Brachial Plexus Injury

PURPOSE

In patients with late brachial plexus birth injuries, sequelae after acute flaccid myelitis, or chronic adult brachial plexus injury, donor nerves for functioning muscle transplantation are often scarce. We present the results of a potential strategy using the phrenic nerve with staged free gracilis transplantation for upper extremity reanimation in these scenarios.

METHODS

A retrospective review was performed on an institutional database of brachial plexus injury or patients with palsy. All patients underwent a staged reconstruction in which the ipsilateral phrenic nerve was extended by an autogenous nerve graft (PhNG), followed by free-functioning gracilis transplantation (PhNG-gracilis).

RESULTS

Nine patients (6 cases of late brachial plexus birth injuries, 2 of acute flaccid myelitis, and 1 of adult chronic brachial plexus injury) were included in this study. The median follow-up period following the PhNG-gracilis procedure was 27 months (range, 12-72 months). The goals of the staged PhNG and PhNG-gracilis were primarily finger extension or finger flexion. In some patients, the technique was used to improve both elbow and finger function, tunneling the muscle through the flexor compartment of the upper arm and under the mobile wad at the elbow. All patients exhibited improvement of muscle strength, including in finger extension (4 patients) from M0 to M2; finger flexion (3 patients) from M0 to M3; elbow extension (1 patient) from M0 to M2; and elbow flexion (1 patient) from M2 to M4.

CONCLUSIONS

A 2-stage PhNG-gracilis may restore or enhance the residual elbow and/or finger paralysis in chronic brachial plexus injuries. A minimum follow-up period of 3 years is recommended. This technique may remain useful as one of the last reconstructive options to increase power in patients with scarce donor nerves.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Reconstruction of cervico-thoracic defect with bipedicled deep inferior epigastric perforator free flap following resection of a giant recurrent thyroid tumor: a case report and review of literature

The bipedicled Deep Inferior Epigastric Perforator (DIEP) flap, originally described and primarily utilized in autologous breast reconstruction for specific cases, has expanded its applications to encompass diverse anatomical regions in recent years. This report presents the case of a 69-year-old woman with a recurrent giant thyroid tumor who underwent surgical resection, resulting in a large cervico-thoracic defect effectively reconstructed using a bipedicled DIEP flap. The patient's postoperative recovery was uneventful, and the follow-up assessments revealed a healthy, well-perfused flap that provided sufficient coverage to critical structures, adequate restoration of the region contour, and enough volume to offset potential adverse effects of subsequent radiation therapy. In addition, this report incorporates a concise literature review highlighting the expanding indications of the bipedicled DIEP flap beyond breast reconstruction, showing the versatility and efficacy of the bipedicled DIEP flap in addressing complex soft-tissue defects in various anatomical areas.

Supercharge End-to-Side Sensory Transfer to A Long Nerve Graft to Enhance Motor Regeneration in A Brachial Plexus Model—An Experimental Rat Study

Background Long nerve grafts will affect muscle recovery. Aim of this study is to investigate if supercharged end-to-side (SETS) sensory nerve transfer to long nerve graft can enhance functional outcomes in brachial plexus animal model.

Methods A reversed long nerve graft (20–23-mm) was interposed between C6 and musculocutaneous nerve (MCN) in 48 SD rats. The sensory nerves adjacent to the proximal and distal coaptation sites of the nerve graft were used for SETS. There were four groups with 12 rats in each: (A) nerve graft alone, (B) proximal SETS sensory transfer, (C) distal SETS sensory transfer, and (D) combined proximal and distal SETS sensory transfers. Grooming test at 4, 8, 12 and 16 weeks, and compound muscle action potentials (CMAP), biceps tetanic muscle contraction force, muscle weight and MCN axon histomorphologic analysis at 16 weeks were assessed.

Results Grooming test was significantly better in group C and D at 8 weeks (p = 0.02 and p = 0.04) and still superior at 16 weeks. There was no significant difference in CMAP, tetanic muscle contraction force, or muscle weight. The axon counts showed all experimental arms were significantly higher than the unoperated arms. Although the axon count was lowest in group C and highest in group D (p = 0.02), the nerve morphology tended to be better in group C overall.

Conclusion Distal sensory SETS transfer to a long nerve graft showed benefits of functional muscle recovery and better target nerve morphology. Proximal sensory inputs do not benefit the outcomes at all.

Safety and Effectiveness of Single Session Mega Volume Fat Grafting for Breast Augmentation: A Space-Creating Concept and Clinical Experiences

BACKGROUND

The main drawback of fat transfer breast augmentation is the need for multiple sessions of fat injection. For approximately 15 years, stem cells and the Brava device for breast expansion have been discussed and extensively investigated to address relevant challenges. However, the safety and effectiveness of autologous fat transfer as a single-session primary breast augmentation technique has not yet been standardized.

OBJECTIVES

The aim of this study was to achieve mega volume fat breast augmentation in a single session by developing a "space-creating" approach that emphasizes the use of highly purified fat to achieve an optimized surgical outcome with large-volume breast augmentation.

METHODS

Female patients who underwent aesthetic breast augmentation (October 2013-October 2020) involving the application of this space-creating technique for mega volume autologous fat transfer were retrospectively enrolled. Inclusion criteria were patients with hypomastia, breast asymmetry, and volume replacement following implant removal with BMI ≥18.5 kg/m2. After macrospace creation, highly purified fat was injected in several rounds during the procedure. A breast massage was performed between each stage (microspace creation). Breast circumference, nipple-inframammary fold distance, and cup size were recorded during 6 months of follow-up.

RESULTS

Three hundred fifty-eight patients met the inclusion criteria. Average fat injection volumes of 510.9 mL in the right breast and 490.8 mL in the left breast resulted in at least a 2 cup size increase. The significant outcome remained stable at 6 months after surgery.

CONCLUSIONS

The space-creating technique and the injection of highly purified fat achieves stable cosmetic outcomes of mega volume breast augmentation in a single session.

LEVEL OF EVIDENCE: 4

Speech and swallowing function following microsurgical reconstruction of palatal defects in a series of six pediatric patients

BACKGROUND

Reconstruction of extensive palatal defects in growing patients aims to restore speech intelligibility and swallowing function while avoiding excessive scarring formation that may cause growth disturbances in the palate and midface region. Free flaps transfer healthy, well-vascularized tissue to the defect area, and their combination with pharyngeal flaps allow for restoration of the velopharyngeal function. We examined speech and swallowing after microsurgical palate reconstruction in a series of six pediatric patients.

METHODS

Radial forearm free flaps were used in all cases, in combination with a superiorly based pharyngeal flap in five cases. Mean age at surgery was 10.7 years. Etiologies included recurrent oronasal fistula due to failed primary cleft palate repair (n = 4), embryonal rhabdomyosarcoma of the maxilla (n = 1), and inflammatory fibrous hyperplasia (n = 1). Speech evaluations (with the Hirose standard and listener ratings) and swallowing assessments (based on videofluoroscopy swallowing studies and patient-reported swallowing and diet) were performed in average 44 months postoperatively.

RESULTS

All flaps survived without major postoperative complications. Speech intelligibility was graded as "excellent" in four patients and "moderate" in two. Hypernasality and nasal obstruction were each judged as "none/minimal" in five cases and "moderate" in one case. All patients tolerated oral diet without significant nasal regurgitation. In five of six patients, the swallowing assessment showed good motion and velopharyngeal closure.

CONCLUSION

Microsurgical reconstruction of extensive palatal defects using radial forearm free flap, with or without a superiorly based pharyngeal flap, is a reliable technique that can deliver substantial improvement of speech and swallowing in pediatric patients.

Chimerization of Monitor Flap in a Vascularized Ulnar Nerve Flap Is an Efficient Way for Vascularity Monitoring and the Reinnervation Checkup after Its Transplantation

Background Free vascularized ulnar nerve flaps (VUNF) are effective method for long nerve defects reconstruction. However, the monitorization of its microvascular circulation and the nerve regrowth can be challenging since it is usually designed as a buried flap. We designed a skin paddle based on a septocutaneous perforator from the ulnar artery that can be dissected and raised in conjunction with the vascularized ulnar nerve flap, which aims to improve postoperative monitorization to optimizing the clinical results.

Methods We retrospectively reviewed 10 cases with long nerve defects who underwent reconstruction using VUNF between June 2018 and June 2019, including eight acute brachial plexus injuries, 1 multiple nerve injury due to a rolling machine accident, and 1 sequalae of nerve injury after arm replantation. All the demographic data, surgical details, outcomes, and perioperative complications were recorded.

Results We evaluated 10 male patients, with a mean age of 34 ± 16 years. Cases included 5 antegrade, 4 retrograde, and 1 U-shaped VUNF. All chimeric skin paddles survived, and all of the underlying nerves presented with adequate circulation and functional improvement. There were no intraoperative or microvascular complications. One skin paddle had a transitory postoperative circulation compromise due to external compression (bandage) which resolved spontaneously after pressure release.

Conclusion VUNF chimerization of a septocutaneous perforator skin flap is a relatively easy and efficient method for postoperative monitorization of the nerve’s microvascular circulation as well as beneficial for postoperative Tinel’s sign checkup to confirm the success of the nerve coaptation. The outcome is potentially improved.

Pediatric Mandibular Reconstruction Using the Vascularized Fibula Free Flap: Functional Outcomes in 34 Consecutive Patients

BACKGROUND

The vascularized fibula free flap is a workhorse flap in pediatric mandibular reconstruction. This study aimed to address functional outcomes, complications, and morbidity associated with the fibula resection in a consecutive series of mandibular reconstruction using this technique in skeletally immature patients.

METHODS

Functional outcomes in terms of maximal mouth opening capacity, patient-reported eating ability, occlusion, and gait were retrospectively reviewed in 34 consecutive pediatric patients (18 males, 16 females) who underwent mandibular reconstruction using the vascularized free fibula flap. Data regarding donor and recipient site complications were also retrieved.

RESULTS

The mean follow-up period was 50.6 months (range, 12-108 months). The average age was 10.3 years (range, 2-15 years). Underlying pathologies included ossifying fibroma, ameloblastoma, mandibular arteriovenous malformation, fibrous dysplasia, Goldenhar syndrome, dentigerous cyst, mandibular lymphoma, odontogenic fibroma, adenomatoid odontogenic tumor, aneurysmal bone cyst, neurogenic sarcoma, and central giant cell granuloma. Defect length ranged from 8 to 17 cm. Mean return to normal ambulation was achieved 12 days postoperatively. All patients reported ability to eat solids and liquids, with 29 of 34 achieving normal mouth opening. Normal or minimally disturbed occlusion was maintained postoperatively in most patients. Temporomandibular joint ankylosis and condylar displacement were each developed in one patient. Two patients reported gait disturbances that receded after physical therapy. No other major donor site complications, including flexion contracture of the great toe, were identified.

CONCLUSIONS

The vascularized fibula free flap is reaffirmed to be the criterion standard for mandible reconstruction in pediatric patients, providing satisfactory functional results and adequate adaptation to the growing facial skeleton with minimal sequelae. Complications regarding hallux function may be prevented by assessing the vascularity of the flexor hallucis longus intraoperatively and ensuring tension-free closure of the donor site.

Double Fascicular Transfer Using Partially Injured Donor Nerves: Is It Powerful Enough to Restore Elbow Flexion in Acute Brachial Plexus Injuries?

BACKGROUND

 Loss of elbow flexion is a common sequela of acute brachial plexus injuries (BPIs). The Mackinnon/Oberlin-II double fascicular transfer (DFT) is a widely used method to restore this function in acute C5-6 or C5-7 injuries. This study attempted to evaluate if this technique can be applied reliably for cases involving C8 and/or T1 injuries.

METHODS

 Adult patients with acute BPIs who underwent the Mackinnon/Oberlin-II DFT in our center between 2008 and 2018 were retrospectively identified. Group I (n = 37) included patients with only C5-6 or C5-7 injury, while group II (n = 32) patients presented C5-8 ± T1 injuries. The demographic data, pre- and postoperative neurologic evaluations, electrodiagnostic studies, and grip strength assessment were collected.

RESULTS

 A total of 69 patients met the inclusion criteria. Preoperatively, the patients in group II presented poorer nerve conduction and electromyography in both the median and the ulnar nerves and the supply muscles. The percentage of M3 achievement in both groups was 91.9 versus 87.5% and M4 was 73.0 and 71.9%, respectively, which both were not statically significant but the achievement of group II was slower than the group I, 1 to 2 months slower, respectively. Both groups had 57.57 and 46.0% of the postoperative grip power compared with the healthy side, the result of shoulder abduction was not different (p = 0.480).

CONCLUSION

 With careful preoperative evaluation, early intervention, appropriate intraoperative functional fascicle selection, and aggressive postoperative rehabilitation, indications for the Mackinnon/Oberlin-II DFT technique can safely include acute C5-8 injuries and even partial T1 acute BPIs.

Reconstruction of mandibular defects involving the central segment with fibula osteoseptocutaneous free flap following ameloblastoma resection: Patient-reported outcomes

OBJECTIVES

Mandibular defects involving the central segment are challenging. This study analyzes the impact of defect extent and reconstruction method on quality of life (QOL) and obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Twenty-nine ameloblastoma patients received segmental mandibulectomy involving the C-segment and immediate fibula free flap reconstruction were recruited. Defects: (C: 2, LC: 11, LCL: 19). Mean defect length: 8.79 cm (± 2.34). Inset: Low-single-barrel (n: 19), with secondary distraction osteogenesis (n: 8/19), high-single-barrel (n: 7), double barrel (n: 3). Patients were surveyed using University of Washington Quality of Life (UW-QOL) and Berlin risk of postoperative sleep apnea questionnaires.

RESULTS

Flap failure: None. Mean follow-up: 109.6 ± 92.8 months.

UW-QOL

Physical function 91.83 (± 14.92); social function 90.17 (± 17.19). No statistical difference between C, LC, and LCL was found, but C group which received low-single-barrel had the lowest score in appearance and chewing domains. In health-related QOL (HR-QOL) compared with 1 month before cancer, 69% reported best results. "Appearance" was the most important issue for the past 7 days, followed by "Chewing," prevailing in LC and C groups that predominately reconstructed by low-single-barrel. Berlin score: 7 patients (4 LCL, 3 LC≥8 cm) were at high risk for postoperative OSA.

CONCLUSION

"Like-with-like" reconstruction with immediate endosteal dental implants yields the best results. Inset of fibula bone could affect outcomes, favoring double-barrel or single-high-barrel inset. Appearance and chewing remain the main concerns, largely, in those with low-single-barrel inset and no dental restoration. After long/extensive LCL and LC mandibulectomies, postoperative OSA warrants further investigation, and modification of resection/reconstruction techniques.

The Combined Use of Curcumin and Platelet-Rich Plasma Enhances Axonal Regeneration in Acute Nerve Injuries: An Experimental Study in a Rat Model

Introduction  The aim of this study was to determine if the combined use of curcumin and platelet-rich plasma (PRP) improves the axonal regeneration process in acutely repaired nerve injuries. Materials and Methods  The right sciatic nerves of 32 Holtzman albino rats were transected and immediately repaired. Four treatments were randomly allocated: (1) nerve repair only; (2) nerve repair + local PRP; (3) nerve repair + intraperitoneal curcumin; and (4) nerve repair + local PRP + intraperitoneal curcumin. Clinical (estimation of sciatic functional index) and electrophysiological outcomes were assessed 4 and 12 weeks after surgery, and histologic evaluations performed 12 weeks after surgery. Results  Group IV (PRP + curcumin) resulted in significantly better outcomes across all the evaluation parameters, compared with the other three groups ( p  < 0.05). Additionally, when used as single adjuvants, both the curcumin (group III) and PRP (group II) groups showed significant improvement over the control group ( p  < 0.05). No significant differences were found between PRP and curcumin when used as sole adjuvants. Conclusion  The combined administration of curcumin + PRP as adjuvants to nerve repair could enhance axonal regeneration in terms of clinical, electrophysiological, and histological parameters in a rat model of acute sciatic nerve injury.

MHC gene configuration variation in geographically disparate populations of California sea lions (Zalophus californianus)

Major histocompatibility complex (MHC) class II DRB genotypes were examined in two geographically isolated populations of California sea lions (Zalophus californianus) (Gulf of California and California coastal Pacific Ocean). Genomic DNA from 227 California sea lions was examined using eight sequence-specific primer (SSP) pairs flanking the putative peptide-binding site. A total of 40 different Zaca-DRB genotype configurations were identified among the 227 individuals. Using SSP-PCR, significant differences were found between coastal California and Gulf of California Zalophus populations in numbers of DRB sequences per individual and configuration of sequences within individuals. Additionally, unique local patterns of MHC diversity were identified among the Midriff Island animals. These population differences are consistent with either ecologically distinct patterns of selection pressures and/or geographical isolation. The consequences of these partitioned MHC configurations at the population level are as yet unknown; however, the worldwide increase in emerging marine diseases lends urgency to their examination.

Accuracy of laparoscopic diagnosis of endometriosis

BACKGROUND AND OBJECTIVE

Laparoscopy is the standard method to visually identify endometriotic lesions under magnification within and outside the minor pelvis. The aim of this study was to analyze the accuracy of laparoscopic visualization in diagnosing the various endometriotic sites as confirmed histologically.

METHOD

Presumed endometriotic sites were observed in 164 patients operated on under the clinical suspicion of endometriosis. Targeted biopsies were performed for histologic corroboration, comparing the laparoscopic findings and diagnosis to the histological results.

RESULT

The histological reports of the biopsies confirmed the presence of endometriosis in 138 patients (84.1%), but in 26 patients (15.9%), no evidence of endometriosis was observed. 100% of "red" lesions, 92% of "black" lesions, and 31% of "white" lesions turned out to be endometriosis. Of the 264 various suspected endometriotic sites observed, 142 (53.8%) were confirmed histologically. The most accurate diagnosis was in lesions on the parietal peritoneum of the pelvis, confirmed in 9/9 cases (100%); the ovarian fossa, confirmed in 8/12 cases (66.7%); and the uterosacral ligaments and posterior surface of the broad ligament, confirmed in 83/138 cases (60.1%). As for the other sites, the histologic confirmation rates in the ovarian surface, bowel serosa, and vesicouterine fold of the peritoneum were 48%, 40%, and 13%, respectively.

CONCLUSION

Endometriosis has a multiple appearance, and the lesions may be confused with nonendometriotic lesions. It is clear that a nonhistology-based diagnosis may lead to unnecessary prolonged medical treatment and operations and may delay the proper treatment measures from being applied. Therefore, a meticulous histological confirmation should still be the first step in the laparoscopic diagnosis and treatment of suspected endometriosis.

Evidence for translational selection in codon usage in Echinococcus spp

We analysed the intragenomic variation in codon usage in Echinococcus spp. by correspondence analysis. This approach detected a trend among genes which was correlated with expression levels. Among the (presumed) highly expressed sequences we found an increased usage of a subset of codons, almost all of them G- or C- ending. Since an increase in these bases at the synonymous sites is against the mutational bias (these genomes are slightly A+-T- rich), we conclude that codon usage in Echinococcus is the result of an equilibrium between compositional pressure and selection, the latter acting at the level of translation, mainly on highly expressed genes. This is the first report where translational selection for codon usage is detected among Platyhelminthes.

Translational selection shapes codon usage in the GC-rich genome of Chlamydomonas reinhardtii

In unicellular species codon usage is determined by mutational biases and natural selection. Among prokaryotes, the influence of these factors is different if the genome is skewed towards AT or GC, since in AT-rich organisms translational selection is absent. On the other hand, in AT-rich unicellular eukaryotes the two factors are present. In order to understand if GC-rich genomes display a similar behavior, the case of Chlamydomonas reinhardtii was studied. Since we found that translational selection strongly influences codon usage in this species, we conclude that there is not a common pattern among unicellular organisms.

Codon usage in Chlamydia trachomatis is the result of strand-specific mutational biases and a complex pattern of selective forces

The patterns of synonymous codon choices of the completely sequenced genome of the bacterium Chlamydia trachomatis were analysed. We found that the most important source of variation among the genes results from whether the sequence is located on the leading or lagging strand of replication, resulting in an over representation of G or C, respectively. This can be explained by different mutational biases associated to the different enzymes that replicate each strand. Next we found that most highly expressed sequences are located on the leading strand of replication. From this result, replicational-transcriptional selection can be invoked. Then, when the genes located on the leading strand are studied separately, the correspondence analysis detects a principal trend which discriminates between lowly and highly expressed sequences, the latter displaying a different codon usage pattern than the former, suggesting selection for translation, which is reinforced by the fact that Ks values between orthologous sequences from C. trachomatis and Chlamydia pneumoniae are much smaller in highly expressed genes. Finally, synonymous codon choices appear to be influenced by the hydropathy of each encoded protein and by the degree of amino acid conservation. Therefore, synonymous codon usage in C.trachomatis seems to be the result of a very complex balance among different factors, which rises the problem of whether the forces driving codon usage patterns among microorganisms are rather more complex than generally accepted.

[Medical-surgical experience of intestinal intussusception. Experience of a university institution]

BACKGROUND

Management of intestinal intussusception in children has evolved from exclusively surgical treatments to nonoperative reduction under fluoroscopic monitoring.

AIM

To report a 10 year experience in a University Hospital in the management of intestinal intussusception.

PATIENTS AND METHODS

Seventy two patients, aged 2 to 72 months of age, with an uncomplicated intussusception, that were treated by barium or air enema, were studied.

RESULTS

The success rate was 73% with barium reductions, and 100% with air reductions. In 17 patients (24%), enema reduction was unsuccessful and were subjected to a surgical reduction.

CONCLUSIONS

Nonsurgical reduction is safe and effective as the initial treatment of uncomplicated intussusception in children.

Compositional pressure and translational selection determine codon usage in the extremely GC-poor unicellular eukaryote Entamoeba histolytica

It is widely accepted that the compositional pressure is the only factor shaping codon usage in unicellular species displaying extremely biased genomic compositions. This seems to be the case in the prokaryotes Mycoplasma capricolum, Rickettsia prowasekii and Borrelia burgdorferi (GC-poor), and in Micrococcus luteus (GC-rich). However, in the GC-poor unicellular eukaryotes Dictyostelium discoideum and Plasmodium falciparum, there is evidence that selection, acting at the level of translation, influences codon choices. This is a twofold intriguing finding, since (1) the genomic GC levels of the above mentioned eukaryotes are lower than the GC% of any studied bacteria, and (2) bacteria usually have larger effective population sizes than eukaryotes, and hence natural selection is expected to overcome more efficiently the randomizing effects of genetic drift among prokaryotes than among eukaryotes. In order to gain a new insight about this problem, we analysed the patterns of codon preferences of the nuclear genes of Entamoeba histolytica, a unicellular eukaryote characterised by an extremely AT-rich genome (GC = 25%). The overall codon usage is strongly biased towards A and T in the third codon positions, and among the presumed highly expressed sequences, there is an increased relative usage of a subset of codons, many of which are C-ending. Since an increase in C in third codon positions is 'against' the compositional bias, we conclude that codon usage in E. histolytica, as happens in D. discoideum and P. falciparum, is the result of an equilibrium between compositional pressure and selection. These findings raise the question of why strongly compositionally biased eukaryotic cells may be more sensitive to the (presumed) slight differences among synonymous codons than compositionally biased bacteria.

Compositional correlations in the chicken genome

This paper analyses the compositional correlations that hold in the chicken genome. Significant linear correlations were found among the regions studied-coding sequences (and their first, second, and third codon positions), flanking regions (5' and 3'), and introns-as is the case in the human genome. We found that these compositional correlations are not limited to global GC levels but even extend to individual bases. Furthermore, an analysis of 1037 coding sequences has confirmed a correlation among GC(3), GC(2), and GC(1). The implications of these results are discussed.

Optimal imaging time for delayed images in the diagnosis of abnormal parathyroid tissue with Tc-99m sestamibi

PURPOSE

Double-phase scintigraphy with Tc-99m sestamibi is a good method to detect hyperfunctioning parathyroid glands. This study tried to determine the best time for delayed images: 2 or 4 hours.

METHODS

Fifty-six patients were studied, and 35 of them had primary hyperparathyroidism (mean age, 53 +/- 13 years; 54% were women). Cervical ultrasonography was performed on 29 of 56 (52%) patients and surgery in 16 of 56 (29%) patients. The dose was 740 MBq (20 mCi) given intravenously, and the acquisition was performed at 10 minutes, 2 h, and 4 h using anterior views, including the mediastinum. Studies that had positive results were analyzed blindly by two independent observers, who selected the best definition for abnormal activity.

RESULTS

Nineteen of 56 (34%) studies were negative and 37 of 56 (66%) were positive, 25 of them with one focus and 12 with two or more parathyroid foci. Analysis revealed 76% agreement between the observers (the rest was classified by consensus). In 70% of the cases, the best delayed image was obtained at 2 hours, in 16% at 4 hours (P < 0.00001), and in 14% both images were similar. In those cases with better images at 4 hours, the 2-hour images also showed the lesions. In two patients, lesions were seen only at 2 hours. These results could be explained by tracer decay, washout of parathyroid activity, or both.

CONCLUSIONS

The best protocol should include the early 10-minute image and the 2-hour delayed view. Further controls do not appear necessary. This may be important for patient throughput.

Synonymous codon choices in the extremely GC-poor genome of Plasmodium falciparum: compositional constraints and translational selection

We have analyzed the patterns of synonymous codon preferences of the nuclear genes of Plasmodium falciparum, a unicellular parasite characterized by an extremely GC-poor genome. When all genes are considered, codon usage is strongly biased toward A and T in third codon positions, as expected, but multivariate statistical analysis detects a major trend among genes. At one end genes display codon choices determined mainly by the extreme genome composition of this parasite, and very probably their expression level is low. At the other end a few genes exhibit an increased relative usage of a particular subset of codons, many of which are C-ending. Since the majority of these few genes is putatively highly expressed, we postulate that the increased C-ending codons are translationally optimal. In conclusion, while codon usage of the majority of P. falciparum genes is determined mainly by compositional constraints, a small number of genes exhibit translational selection.

Is the addition of ECG gating to technetium-99m sestamibi SPET of value in the assessment of myocardial viability? An evaluation based on two-dimensional echocardiography following revascularization

The main goal of this study was to evaluate whether the addition of ECG gating to technetium-99m sestamibi single-photon emission tomographic (SPET) perfusion imaging assists the prediction of recovery of regional wall motion abnormalities after revascularization. Thirty-six patients with coronary artery disease were included in the study. All had wall motion abnormalities, and 31 (86%) had a clinical history of myocardial infarction. Coronary artery bypass surgery was performed in 18 patients and angioplasty in the remainder. All underwent ECG-gated and non-gated SPET at rest and after intravenous dipyridamole. Two-dimensional echocardiography was performed at a mean of 27 days before revascularization and at a mean of 69 days following revascularization to assess segmental wall motion changes. Perfusion prior to revascularization was analysed qualitatively and quantitatively on gated and non-gated SPET, and the results compared with those of echocardiography. Bullseye parameters were obtained from a normal database, generated from data in 40 normal volunteers, using dipyridamole ECG-gated and non-gated sestamibi SPET. There was good concordance between gated and non-gated qualitative analysis (79% with kappa=0.65) for normal, viable or necrotic segments. Gated SPET predicted functional recovery in 27 of 35 (77%) segments showing echocardiographic improvement while non-gated SPET did so in 30 of 39 (77%) such segments. Gated SPET predicted no functional recovery in 20 of 45 (44%) segments that did not show improved wall motion after revascularization, while with non-gated SPET the figure was 18 of 51 (35%). The positive predictive values of gated and non-gated SPET with regard to the recovery of wall motion following revascularization were 52% and 48%, while the negative predictive values were 71% and 67%, respectively. 99mTc-sestamibi had a low predictive value for recovery of function if visual assessment was used in the analysis of SPET data. Quantitative bullseye sestamibi parameters (defect extension and severity, reversibility and percentage change in extension), from gated or non-gated studies, appear best to distinguish which segments will display improved motility on the echocardiogram after revascularization. The addition of ECG gating does not significantly increase the predictive value of SPET imaging with regard to recovery of function.

Sex steroid regulation of chin-marking behavior in male New Zealand rabbits

Chin-marking behavior (chinning) was evaluated daily in nine intact adult male rabbits. All subjects (Ss) displayed chinning (mean of means +/- SE = 61 +/- 7 marks/10 min) but the frequency of this behavior varied largely across them (range of mean chinning frequency = 19-84 marks/10 min). Chinning frequency showed abrupt variations at intervals of 2-3 days, but periodogram analysis did not reveal the existence of an endogenous rhythm in this behavior. Castration significantly decreased (mean of means +/- SE = 29 +/- 9 marks/10 min; p < 0.01). but did not suppress chinning. Testosterone propionate (TP; 1 mg/day for 16 days) restored chinning in castrated Ss to slightly below precastration levels (mean +/- S.E. V 53 +/- 13 marks/10 min). The daily administration of 1 microgram estradiol benzoate (EB) plus 1 mg dihydrotestosterone propionate (DHTP) stimulated chinning within 2 days (mean increase = 147%; p < 0.005). DHTP (1 mg/day) given alone stimulated chinning only after 11 days of treatment (mean increase = 475%; p < 0.01). At higher doses, both DHTP (10 mg/day) and EB (10 or 50 micrograms/day) stimulated chinning by 450%, 80%, and 100%, respectively, over baseline values. Results indicate that chinning largely depends on testicular steroids. Androgen receptor occupation by T or DHT, which is enhanced by E, optimally activates chinning.

Chin-marking behavior in male and female New Zealand rabbits: onset, development, and activation by steroids

Chin marking (chinning) frequency was determined daily in 25 male and 24 female New Zealand rabbits aged 31-150 days. Chinning appeared earlier in females (mean +/- SD = 41 +/- 16 days) than in males (47 +/- 13 days). Between days 30-50, females displayed chinning more frequently than males. Thereafter, chinning increased steadily in both sexes up to day 100. Chinning curves levelled on days 100 and 140 in males and females, respectively. Profile analysis of male and female chinning curves showed significant differences in their slopes and in their population means (p < 0.001). At 7 months of age (days 210-224), both sexes displayed adult chinning frequencies: mean of means +/- SD = 103 +/- 18 and 79 +/- 14 marks/10 min in males (n = 8) and females (n = 8), respectively. The administration of testosterone propionate (TP, 1 mg/day) or estradiol benzoate (EB, 1 microgram/day) to males and females, respectively, from days 31-50, stimulated higher chinning frequencies than those displayed by untreated animals. Results suggest that chinning frequency increases throughout development largely as a consequence of a concomitant increase in sex steroid secretion.

[Patients with liver cirrhosis: mouth-cecum transit time and gastric emptying of solid foods]

As altered gastrointestinal motility could be involved in the pathogenesis of small intestinal bacterial overgrowth observed in liver cirrhosis, we investigated mouth to caecum transit time (MCTT) and solid meal gastric emptying (SMGE) in patients with cirrhosis. MCTT was estimated in 20 cirrhotics and 12 healthy controls using lactulose hydrogen breath test. SMGE was measured in 12 patients with cirrhosis and 27 controls by means of 99-m Tc-sulphur colloid labelling egg albumin and gamma scintigraphy. T1/2 and percentage of marker remaining in stomach (MRS) at 60, 90, and 120 min were calculated. MCTT was prolonged in patients with cirrhosis (111 +/- 7 min) compared to controls (83 +/- 6 min; p < 0.02). No significant differences were demonstrated in SMGE t1/2 between controls (84 +/- 5 min) and cirrhotics (91 +/- 6 min). Also, MRS was similar in patients with cirrhosis and healthy controls at 60, 90 and 120 min. We conclude that MCTT is prolonged in patients with cirrhosis. In addition, our data suggest that pyloruscaecum component plays the main role in delaying orocaecal transit time in cirrhosis.

Variations in chin-marking behavior of New Zealand female rabbits throughout the whole reproductive cycle

Chin-marking (chinning) was measured daily in intact New Zealand female rabbits across their whole reproductive cycle. In Experiment 1 does displayed during estrus (48 days studied) three phases, adaptation, growth and plateau, characterized by progressively higher chinning scores (mean +/- SE = 3.6 +/- 1.1; 17.7 +/- 6.3; 26.6 +/- 4.9 marks/10 min, respectively). Despite great quantitative differences among individuals, these 3 phases and the occurrence of chinning "peaks" at 4-6 day intervals were consistently observed in all subjects (Ss). Mating provoked, within one hour, a dramatic decrease in chinning. Both pregnant and pseudopregnant Ss showed low chinning scores for the first 13 days after mating (combined mean +/- SE = 7.3 +/- 3.8 marks/10 min). From days 14 to 30 postcoitus chinning gradually rose in the pseudopregnant Ss (mean +/- SE = 12.7 +/- 5.4 marks/10 min) while remaining low in the pregnant ones (mean +/- SE = 2.6 +/- 1.9 marks/10 min). Parturition allowed a gradual rise in chinning scores. In Experiment 2 the same Ss were explored across a second reproductive cycle that included lactation. In contrast to Experiment 1, no significant variations in chinning were displayed along estrus, Ss showing high chinning scores already on the first day of observation (mean +/- SE from 12 days = 19.2 +/- 6.7 marks/10 min). In agreement with Experiment 1, mating drastically reduced chinning scores. Low levels were maintained throughout pregnancy (mean +/- SE = 3.4 +/- 2.4 marks/10 min) and lactation (mean +/- SE = 3.3 +/- 4.8 marks/10 min). Weaning allowed a gradual increase in chinning scores.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of component- total task relations: order of component- total task practice and total task predictability

The Complex Coordination Test was used to examine component-total task relationships when component tasks are practiced in different orders. Sixty subjects practiced (two trials of two minutes each) on six component tasks and on the total task, practicing these in various orders. Part-tasks were three single-level (one rudder and two stick control) tasks and three double-level (one stick-stick and two rudder-stick) tasks. Correlational analyses were performed to determine component-total task relationships and component to total task predictability. It was found that order of part-task practice affects total task proficiency. Also, part-task scores can be combined in a statistically independent manner to yield prediction scores on a more complex task only when a specific double-level task is combined with a specific single-level task. It was also found that observed and predicted total task scores agree better when double-level tasks are practiced before rather than after the total task. Finally, prior practice on double-level tasks led to better total task proficiency than did prior practice on single-level tasks.

Human dermo-optical perception: colors of objects and of projected light differentiated with fingers

It has been popularly reported that some persons can discriminate nonvisually among stimulus objects usually requiring visual cues. A female S ( A) was reported to possess the ability of so-called “finger-sight” or “dermo-optical perception.” To determine whether there was anything unusual about her sensory behavior, S and three controls were tested using plastic discs, projected light and playing cards as stimuli. The stimuli were presented so as to prevent use of visual cues for identification. Results indicated that S performed reliably above chance and above the level of the controls as a group in discriminating colored plastic discs, colored projected lights, and in discriminating the suit and number of playing cards. Some controls also performed reliably above chance but below A.

Studies of helicopter pilot performance. II. The analysis of task dimensions

Measures of helicopter pilot proficiency were obtained on several hundred student pilots in the Primary and Basic training phases. Measures were based on students' performance on 75 and 76 tasks (items), for the Primary and Basic phases, respectively. Intercorrelations of tasks in each phase were subjected to factor analysis. The 12 factor rotation solutions were presented in detail for each phase, and the 18 and 24 factor rotations solutions were described briefly. In almost all cases the same tasks (e.g., RPM; Altitude) tended to cluster together across different maneuvers. The factors are interpreted in terms of the operations performed for each task, and the theoretical and practical implications of the findings are discussed.

Studies of helicopter pilot performance. I. The analysis of maneuver dimensions

Measures of helicopter pilot proficiency were obtained on samples of student pilots in two training phases. Measures were based on students' performance on 16 and 12 separate maneuvers in the Primary and Basic training phases respectively. Intercorrelatitons of maneuvers in each phase were subjected to factor analysis. In both phases maneuver performance could be described in terms of six or seven clearly interpretable common factors. The results were discussed in terms of the implications for understanding the structure and measurement of skilled psychomotor performance.