Skin-sparing mastectomy and immediate reconstruction with a deep inferior epigastric perforator flap

BACKGROUND: It is important for breast reconstruction after mastectomy to recreate immediately good breast symmetry with an adequate amount of soft tissue. METHODS: Eight patients with breast cancer underwent skin-sparing mastectomy and immediate reconstruction with a deep inferior epigastric perforator flap. This operative technique, and the results, advantages, and disadvantages of the technique were assessed. RESULTS: Seven patients had stage IIA disease, and one patient had stage I disease. An arc-shaped incision was made just at the lateral border of the breast in all patients. Three patients had a separate periareolar incision, and one had a circumferential nipple incision. There was 100% flap survival, and good breast symmetry was achieved in all patients. No major perioperative complications occurred in this series. A small amount of fat necrosis occurred in one flap. One patient had slight abdominal bulging. Minor wound-healing problems at the lateral breast skin envelope occurred in two patients. CONCLUSION: These data indicate that skin-sparing mastectomy and immediate reconstruction with a DIEP flap is a reliable and safe technique. This method is a potentially useful surgical technique, which has achieved very promising results.     

Nav1.1 channels with mutations of severe myoclonic epilepsy in infancy display attenuated currents

Severe myoclonic epilepsy in infancy (SMEI) is characterized by intractable febrile and afebrile seizures, severe mental decline, and onset during the first year of life. Nonsense, frameshift, and missense mutations of SCN1A gene encoding the voltage-gated Na(+) channel alpha-subunit type I (Na(v)1.1) have been identified in patients with SMEI. Here, we performed whole-cell patch-clamp analyses on HEK293 cells expressing human Na(v)1.1 channels bearing SMEI nonsense and missense mutations. The mutant channels showed remarkably attenuated or barely detectable inward sodium currents. Our findings indicate that SMEI mutations lead to loss-of-function and may contribute to the development of SMEI phenotypes.     

Long-Term Course of Childhood Epilepsy with Intractable Grand Mal Seizures

Abstract: Twenty-nine children with childhood epilepsy characterized by frequent grand mal (generalized tonic-clonic) seizures in spite of maximal doses of antiepileptic drugs and by an early onset of seizures (before 1 :year of age) were followed up for more than 5 :years. The children were divided into 3 :groups: severe myoclonic epilepsy in infancy (SME), no SME, and intractable childhood epilepsy with generalized tonic-clonic seizures (GTC). In all the 3 :groups, the grand mal seizures persisted, whereas the other types of seizures tended to disappear as the patients aged, and the prognosis for mental development was poor. In the majority of cases in all the 3 :groups, the waking grand mal seizures altered to sleep grand mal seizures with aging. Two pairs of monozygotic twins with SME suggested that genetic factors play a role in this epileptic syndrome. Intractable childhood epilepsy with GTC is distinguished by the absence of other types of generalized seizures. It cannot be regarded as an epileptic syndrome, but its pathogenesis and treatment require further studies.     

REFRACTORY DIVERTICULAR COLITIS WITH PROGRESSIVE ULCERATIVE COLITIS‐LIKE CHANGES EXTENDING TO THE RECTUM

A 68‐year‐old man visited our department because of diarrhea and bloody stools. Colonoscopy revealed diverticula scattered in the sigmoid colon with localized mucosal edema and reddening. The mucosa became somewhat rough 9 months later, and had an erosive, ulcerative colitis (UC)‐like appearance after a further 6 months, with these changes extending to the rectum. These findings led to a diagnosis of diverticular colitis (DC) with UC‐like changes. The condition was refractory to treatment including drug therapy and was thus surgically treated. No cases of DC have been reported in Japan, and a refractory case of DC with progressive UC‐like changes extending to the rectum is rare even in Europe and the USA.     

Calcineurin/NFAT Pathway: A Novel Regulator of Parturition

Problem  The oxytocin (OT)–oxytocin receptor (OTR) system plays an important role in mammalian parturition. However, we found OTR-deficient (OTRKO) mice are fertile and deliver at term without birth defects, thus alternative pathways inducing parturition can be hypothesized.
Methods of study  We tested the gene expression profile of OTRKO mice using suppressive subtractive hybridization, and focused on the calcineurin/nuclear factor of activated T cells (NFAT) pathway. We examined the expression and localization of this pathway in mouse parturition.
Results  Calcineurin and NFATc1 were detected in the decidua of pregnant uteri at term using immunohistochemistry (IHC). We identified higher activation levels of NFATc1 in wild type (WT) than in OTRKO mice and increased calcineurin A and NFATc1 mRNA levels during pregnancy. Moreover, injection of FK506, the inhibitor of this pathway, prolonged the delivery of the first pup.
Conclusion  Our findings suggested that the calcineurin/NFAT pathway might play a substantial role in initiation of labor.     

Myelin-associated glycoprotein reduces axonal branching and enhances functional recovery after sciatic nerve transection in rats

The mature peripheral nervous system (PNS) generally shows better regeneration of injured axons as opposed to the central nervous system (CNS). However, complete functional recovery is rarely achieved even in the PNS although morphologically good axonal regeneration often occurs. This mainly results from aberrant reinnervation due to extensive branching of cut axons with consequent failure of synchronized movements of the muscles. Myelin-associated glycoprotein (MAG), a well-characterized molecule existing both in the CNS and PNS myelin, is considered to be a potent inhibitor of axonal regeneration especially in the CNS. In the present study, we investigated whether MAG has any effects not only on axonal elongation, but also on axonal branching. We show herein that MAG minimized branching of the peripheral axons both in vitro and in vivo via activation of RhoA. Furthermore, after sciatic nerve transection in rats, focal and temporary application of MAG to the lesion dramatically enhanced the functional recovery. Using double retrograde labeling and preoperative/postoperative labeling of spinal neurons, reduced hyperinnervation and improved accuracy of target reinnervation was confirmed, respectively. In conclusion, as MAG significantly improves the quality of axonal regeneration, it can be used as a new therapeutic approach for peripheral nerve repair with possible focal and temporary application.     

Axonal supercharging technique using reverse end-to-side neurorrhaphy in peripheral nerve repair: an experimental study in the rat model

OBJECT: In an attempt to improve peripheral nerve repair, the influence of the addition of reverse end-to-side neurorrhaphy for an injured peripheral nerve was investigated in the rat sciatic nerve transection model. METHODS: Twelve Sprague-Dawley rats were divided into two groups (six rats in each group). In Group I, the right sciatic nerve was cut at a point distal to the gluteal notch and repaired using end-to-end neurorrhaphy with four 10-0 nylon epineurial sutures. In Group II, after performing the same procedure as in Group I, the left sciatic nerve was cut distally and passed through a subcutaneous tunnel to the right side. The proximal stump of the left sciatic nerve was coapted to the epineurial window of the right sciatic nerve distal to the injured point in an end-to-side fashion using 10-0 nylon epineurial sutures. The effects were evaluated using analgesimeter recordings for the hind paw, electrophysiological tests, measurement of the muscle contraction force, a double-labeling technique, weight measurement and histological examination of the gastrocnemius muscle, histological examination of the bilateral sciatic nerves, and immunofluorescent staining. RESULTS: Results from the many tests used to evaluate the reverse end-to-side neurorrhaphy technique indicated that functional recovery of the denervated target organs was promoted by axonal augmentation. CONCLUSIONS: The reverse end-to-side neurorrhaphy technique could be useful in peripheral nerve repair.     

Whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography images before and after chemotherapy for Kaposi sarcoma and highly active antiretrovirus therapy

Kaposi sarcoma is an acquired immunodeficiency syndrome-related disease that mainly involves the skin, gastrointestinal gut, and lungs. Whole-body 18F-fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT) scanning is useful for simultaneous detection of multiple lesions of Kaposi sarcoma. We present a 67-year-old man with a history of infection with human immunodeficiency virus who presented with numerous cutaneous lesions. FDG-PET/CT images showed lesions in the skin, lung, and lymph nodes. The gastrointestinal lesions were detected using gastric fiberscopy (GF) and colon fiberscopy (CF). After Kaposi sarcoma therapy, the uptake in the lesions of the skin, lung, and lymph nodes decreased, but new lesions were detected in the pancreas and lumbar spine. He had pancreatitis and Candida spondilitis. Whole-body FDG-PET/CT is useful for detecting lesions and determining the extension to which the disease has spread, adding the gastrointestinal lesions by GF and CF. After therapy, FDG-PET/CT can be used to demonstrate which lesions remain active and to determine the overall response to treatment. In this case, we show how useful FDG-PET/CT is and how difficult it is to treat Kaposi sarcoma.     

Structure of the Pseudomonas aeruginosa transamidosome reveals unique aspects of bacterial tRNA-dependent asparagine biosynthesis

Many prokaryotes lack a tRNA synthetase to attach asparagine to its cognate tRNA^Asn, and instead synthesize asparagine from tRNA^Asn-bound aspartate. This conversion involves two enzymes: a nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) that forms Asp-tRNA^Asn, and a heterotrimeric amidotransferase GatCAB that amidates Asp-tRNA^Asn to form Asn-tRNA^Asn for use in protein synthesis. ND-AspRS, GatCAB, and tRNA^Asn may assemble in an ∼400-kDa complex, known as the Asn-transamidosome, which couples the two steps of asparagine biosynthesis in space and time to yield Asn-tRNA^Asn. We report the 3.7-Å resolution crystal structure of the Pseudomonas aeruginosa Asn-transamidosome, which represents the most common machinery for asparagine biosynthesis in bacteria. We show that, in contrast to a previously described archaeal-type transamidosome, a bacteria-specific GAD domain of ND-AspRS provokes a principally new architecture of the complex. Both tRNA^Asn molecules in the transamidosome simultaneously serve as substrates and scaffolds for the complex assembly. This architecture rationalizes an elevated dynamic and a greater turnover of ND-AspRS within bacterial-type transamidosomes, and possibly may explain a different evolutionary pathway of GatCAB in organisms with bacterial-type vs. archaeal-type Asn-transamidosomes. Importantly, because the two-step pathway for Asn-tRNA^Asn formation evolutionarily preceded the direct attachment of Asn to tRNA^Asn, our structure also may reflect the mechanism by which asparagine was initially added to the genetic code.Accurate translation of the genetic code into a protein sequence relies on a covalent attachment of amino acids to cognate tRNAs that are later used in protein synthesis (1). This attachment is catalyzed by aminoacyl-tRNA synthetases (aaRSs), each specific to one amino acid and a set of tRNA isoacceptors (2). However, the majority of prokaryotes lack several tRNA synthetases, particularly asparaginyl-tRNA synthetase (AsnRS), which ligates asparagine to tRNA^Asn (3, 4). In these organisms, asparagine is synthesized in a two-step, tRNA-dependent pathway (5). First, a nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) attaches aspartate to tRNA^Asn to form Asp-tRNA^Asn (6, 7). Then the tRNA-bound aspartate is converted to asparagine by the amidotransferase (AdT) GatCAB to yield the final product, Asn-tRNA^Asn (6, 8–13). Likewise, in prokaryotes lacking glutaminyl-tRNA synthetase (GlnRS), Gln-tRNA^Gln is formed by the sequential actions of a nondiscriminating glutamyl-tRNA synthetase (ND-GluRS) (14) and an AdT (5). In bacteria, the role of AdT is played by GatCAB (15), whereas in archaea, it is played by GatDE (16, 17).More than 25 years ago (18), it was proposed that ND-aaRSs and AdTs may form a complex—now called a transamidosome—to couple the two steps of Asn-tRNA^Asn formation in space and time and allow efficient transfer of Asp-tRNA^Asn from the aaRS to the AdT. The first characterized transamidosome was the Asn-transamidosome from Thermus thermophilus (TtAsn-transamidosome) (19, 20). This complex was identified as a tRNA-dependent association of AspRS2 (TtAspRS2) and GatCAB in a 2:2:2 ratio. It was shown that transamidosome formation stabilizes interactions between subunits of GatCAB (21) and protects Asn-tRNA^Asn from hydrolysis, with product release being rate-limiting (19). In the complex, the AspRS forms a dimer with only one catalytic site active at a time (21). It was suggested that the key advantages of asparagine formation by the transamidosome compared with separate enzymes are enhanced aspartylation of tRNA^Asn and better prevention of the misacylated Asp-tRNA^Asn from use in translation, because this would compromise the fidelity of protein synthesis (19–21).Importantly, TtAspRS2 was acquired through horizontal gene transfer from archaea (10), and lacks the GAD domain typical of bacterial AspRSs (22). The TtAsn-transamidosome crystal structure suggests that a complex between bacterial ND-AspRS and GatCAB should be less stable and more structurally distinct than the T. thermophilus complex, owing to the presence of the GAD domain in bacterial ND-AspRS (21, 23). Consistent with this notion, the stable association of the Helicobacter pylori ND-AspRS (HpND-AspRS) with GatCAB requires the presence of an auxiliary factor, Hp0100 (23, 24). In the complex, the activity of the HpND-AspRS is unchanged, although the activity of GatCAB increases (23); however, Hp0100 is phylogenetically limited to ε-proteobacteria (23). Therefore, most bacteria have a structurally and, possibly, functionally distinct class of transamidosomes than those described by the T. thermophilus and H. pylori complexes.In the bacterium Pseudomonas aeruginosa, Asn-tRNA^Asn formation is catalyzed by GatCAB and bacterial ND-AspRS, and thus represents the most common type of bacterial Asn-transamidosome (25). Here we report the crystal structure of the P. aeruginosa Asn-transamidosome (PaAsn-transamidosome), which represents the transamidation state of the Asn-tRNA^Asn formation. The structure suggests that the additional GAD domain within the ND-AspRS changes the overall architecture of the complex relative to the previously described TtAsn-transamidosome. Consistent with the structure, our in vitro measurements show that PaAsn-transamidosome has unique kinetic properties and functions primarily to enhance tRNA^Asn turnover and facilitate Asp-tRNA^Asn handoff from AspRS to GatCAB.