Three developmental compartments involved in rib formation

When the thoracic somitic mesoderm was separated from the neural tube and the notochord with a piece of aluminum foil in two-day chick embryos, seven days after the operation ribs lacked their proximal part. The embryos were rescued by co-transplanting the notochord, the ventral half of neural tube, or QT6 cells transformed with Shh, on the somite side of the aluminum foil insert. Thus, proximal rib development depends on the notochord and the ventral neural tube, an effect which might be mediated through Shh secreted by these axial tissues. On the other hand, when the thoracic somitic mesoderm was separated from the surface ectoderm by a piece of polyethylene terephthalate film, the distal parts of the ribs were missing, suggesting that distal rib development depends on surface ectoderm. In these embryos, expression of Pax3 was weak and perturbed showing that the dermomyotome developed abnormally. It is not clear whether the development of distal rib is mediated by the dermomyotome, or the ectoderm. It has previously been shown that sternal rib development depends on lateral plate mesoderm. As to the distal rib, it is considered to be composed of two parts. Thus, the rib is composed of three developmental compartments, in agreement with a recently presented classification of somite derivatives as primaxial and abaxial.

A comparative study of the efficacy and safety profiles between fluvoxamine and nortriptyline in Japanese patients with major depression

OBJECTIVE

The aim of this study was to compare the efficacy and safety profiles between fluvoxamine and nortriptyline in Japanese patients with major depression.

METHODS

The efficacy and safety profiles of fluvoxamine, a selective serotonin-reuptake inhibitor, and nortriptyline were compared under a single-blind fashion in 74 Japanese patients with major depression. The efficacy was assessed using the 17-item Hamilton Rating Scale for Depression (HAM-D), Clinical Global Impression Scale (CGI) severity and improvement scores, while the safety profiles were assessed using the UKU Side Effect Rating Scale at baseline, and on days 7, 14, 28 and 56. Moreover, with the aim of determining the distinct efficacy profiles of each drug, the effects on each of the factor scores extracted by the principal component analysis performed for HAM-D scores were compared between drugs.

RESULTS

Both drug groups showed significant amelioration of depressive symptomatology over the trial period lasting for 8 weeks. Statistical analyses revealed no significant between-group differences regarding the efficacy assessed by either HAM-D or CGI scores; however, the efficacy of nortriptyline tended to appear earlier than that of fluvoxamine. Moreover, no significant differences were obtained for the factor scores, representing 'depressed mood', 'physical symptoms' or 'sleep disturbances', although 'sleep disturbances' appeared to improve earlier in the nortriptyline group than in the fluvoxamine group. As for the safety profiles, the nortriptyline group scored a significantly higher incidence of adverse events such as dysarthria or orthostatic dizziness, as well as increased heart rate.

CONCLUSIONS

These findings suggest that fluvoxamine is generally comparable to nortriptyline in its efficacy and superior in its safety profile, in accordance with findings obtained in previous comparative clinical trials conducted in Caucasian populations.

Enterocele associated with rectocele revealed by dynamic pelvic CT

Enterocele is often associated with other pelvic floor disorders but it is not always possible to detect by clinical examination. Defecography with peritoneography and/or barium meal intake has recently been developed as a new method to identify enterocele, but this method is an invasive procedure. Multislice computed tomography was performed at rest and during simulated defecation to evaluate an 80-year-old female patient who had a defecation disorder and was diagnosed as having rectocele based on results from defecography and clinical findings. Multiplanar reconstruction images were generated for image evaluation. Using this novel method of dynamic pelvic computed tomography, a third-degree enterocele was clearly demonstrated in this case.

Somite development without influence of the surface ectoderm in the chick embryo: the compartments of a somite responsible for distal rib development

In the development of the somite, signals from neighboring tissues have been suggested to play critical roles. We have found that when interaction between the ectoderm and the somite is blocked by inserting a piece of polyethylene terephatalate film between them in 2-day-chicken embryo, one of the derivatives of somite, the distal rib, did not form. We examined somite development after the operation, to know the correlation between somite development and distal rib formation. In the operated embryo, the dermomyotome was medio-laterally shorter than in the normal embryo, and Pax3 and Sim1 expressions that are seen in the lateral part of normal dermomyotomes were not found, suggesting that the lateral part of the dermomyotome was missing. Although the sclerotome appeared to be normal in its histology and Pax1 expression pattern in the operated embryo, we could not detect the expression of either Scleraxis nor gamma-FBP that are expressed in the cells around the boundaries between the adjacent dermomyotomes in normal embryos. Thus, under the influence of surface ectoderm, the lateral part of dermomyotome and/or the mesenchyme around rostral and caudal edges of dermomyotomes are suggested to play an important role in the distal rib development.

Effects of toremifene (TOR) and tamoxifen (TAM) on serum lipids in postmenopausal patients with breast cancer

This study clarified the difference in the effects on serum lipids between toremifene (TOR) and tamoxifen (TAM). To remove influencing factors, we investigated adjuvant therapy for hormone receptor-positive patients with breast cancer without lymph node metastasis. The subjects were 65 patients who were enrolled in a multicenter randomized comparative study between April 1997 and March 2001. As adjuvant therapy, 20 mg of TAM or 40 mg of TOR was administered for 1 year. The levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A-1 (Apo A-1), apolipoprotein A(Apo B), and lipoprotein a (Lp(a)) were measured prior to administration and 3, 6, and 12 months after the start of administration. TC, LDL-C, Lp(a) and Apo B significantly decreased from the third month of administration compared with values before the start of administration in both the TOR and TAM groups. HDL-C significantly increased from the third month only in the TOR group. TG significantly increased in the TAM group but significantly decreased in the TOR group in the 12th month of administration. When these two groups were compared, HDL-C was significantly higher (p < 0.01) and TG was significantly lower (p < 0.01) in the TOR group in the 12th month. Improvement of abnormal values of TG, HDL-C and LDL-C was better in the TOR group than in the TAM group after administration for 12 months. The effect on lipid metabolism showed different profiles between the two selective estrogen receptor modulators (SERMs), and TOR gave better results than TAM.

Formaldehyde concentration in the air and in cadavers at the gross anatomy laboratory in Hiroshima University

The formaldehyde concentration in the air and in various tissues of 35 human cadavers were measured during a gross anatomy course held at the Faculty of Medicine of Hiroshima University in the 2003 educational year. Atmospheric formaldehyde levels were 0.25-0.55 ppm and thus less than the upper limit of the guideline for formaldehyde exposure (0.5 ppm) set by the Japan Society for Occupational Health (1988) except for one out of 10 measurements. The formaldehyde concentrations in tissues were as follows: the lung, 0.12 +/- 0.09% (n=29); the liver, 0.12 +/- 0.09% (n=29); and the brachioradialis muscle, 0.11 +/- 0.09% (n=30). Considerable variation was found among the cadavers and these values were lower than those of Tsurumi University which provided the only other data (average formaldehyde concentrations ranged from 0.27 to 0.32%). At Hiroshima University, blood is allowed to drain during embalming, whereas it is not at Tsurumi University. Differences in the embalming procedure are thus responsible for low and fluctuating formaldehyde concentrations in cadavers at Hiroshima University, and it is conceivable that relatively low formaldehyde levels in the air result from low formaldehyde concentrations in cadavers and good room ventilation (10 room-air changes per hour). However, the Japanese Ministry of Health and Welfare recommended lower formaldehyde exposure levels (0.08 or 0.25 ppm) in 2002. Thus, it may be necessary to further reduce formaldehyde levels in the gross anatomy laboratory by means of such measures as neutralizing formaldehyde with ammonium carbonate; using a locally ventilated dissection work-table, etc.

Monokaryotic chloroplast mutation has no effect on non-Mendelian transmission of chloroplast and mitochondrial DNA in Chlamydomonas species

We studied whether the monokaryotic chloroplast (moc) mutation affects the transmission of chloroplast and mitochondrial DNA in Chlamydomonas species. We used a previously isolated moc mutant from our cell line G33, which had only one large chloroplast nucleus. To obtain zygotes, we crossed the mutant cells with wild-type cells, and mutant cells with receptive mates (females [mt+] with males [mt-]). In these zygotes, we recorded preferential dissolution of mt- parental chloroplast nuclei and fusion of the two cell nuclei. Antibiotic-resistance markers of chloroplast DNA were maternally transmitted in all crosses. PCR analysis of the cytochrome b (cob) gene sequence showed that the mitochondrial DNA was paternally transmitted to offspring. These results suggest that the moc mutation did not affect the organelle DNA transmission.

Local correction of a transverse loop colostomy prolapse by means of a stapler device

Prolapse is a common complication in patients with a transverse loop colostomy. In most cases, the prolapse can be managed conservatively awaiting time for closure eventually. However, loop stoma may also be intentionally permanent or the patient may be too fragile to have the colostomy closed and in these cases a laparotomy is required for correction of the prolapse. A simple method allowing local correction of the prolapsed loop stoma is described.

Pathophysiology and prevention of loop stomal prolapse in the transverse colon

We investigated both pathogenesis and prevention of loop transverse stomal prolapse. Seven patients with reducible prolapsed stoma were studied under fluoroscopy after staining the prolapsed stoma and the colon by barium medium while prolapsing or reducing the stoma with or without the stomal wall pressed on to the abdominal wall of fascial plane. All prolapses occurred in the distal limbs of the loop stoma with the distal transverse colons redundant. The prolapse started around the mucocutaneous suture with the stoma inflated and the colon in it depressed and proceeded in accordance with an addition of abdominal pressure, but did not occur by pressing of the stomal wall. Prolapse of transverse loop stoma occurs when redundant colon invades the stoma with an abdominal pressure. Stomal prolapse might be prevented by fixation of the colon to the fascia.

Strict paternal transmission of mitochondrial DNA of Chlamydomonas species is explained by selection against maternal nucleoids

The non-Mendelian inheritance of organelle DNA is common in most plants and animals. Here we examined inheritance mechanisms involved in the transfer of mitochondrial DNA. We successively backcrossed (to F(5)) two interfertile strains of the unicellular isogamous haploid algae Chlamydomonas reinhardtii and Chlamydomonas smithii to match nuclear backgrounds and examine transmission patterns of mitochondrial DNA by PCR analysis of cob gene sequences. Mitochondrial DNA was strictly transmitted paternally. To investigate the behavior of parental mitochondrial DNA, we used F(5) progeny to form zygotes and isolated single zygotes. The results showed selective disappearance of maternal mitochondrial nucleoids occurred between 3 and 6 h after zygote formation.

Relationship of the fistulas to the rectum and genitourinary tract in mouse fetuses with high anorectal malformations induced by all-trans retinoic acid

Since high anorectal malformations with fistulae in human embryos and fetuses of successive developmental stages have not been reported, the embryologic relationship between the rectal fistula (RF) and the genitourinary tract (GUT) in high anorectal agenesis (ARA) remains to be elucidated. This study investigates the developmental relationship between the RF and the GUT in male and female fetuses with high ARA using our established model for high ARA with fistula in mice. Pregnant mice received all-trans retinoic acid suspended in corn oil (5 mg/ml) 100 mg/kg i.p. on day 9 of pregnancy. All fetuses were removed from the uterus on a single day from days 12 to 18 of pregnancy. The caudal regions were analyzed histologically with hematoxylin and eosin staining. All fetuses examined had high ARA with fistula. On day 12 of pregnancy, an anomalous communication was seen between the urogenital sinus (UGS) and the rectum. In the affected female fetuses, on day 14 of pregnancy the paramesonephric (müllerian) ducts and müllerian tubercle were located above the rectocloacal fistula (RCF), and on day 18 of pregnancy the uterovaginal canal was located between the cloaca and the RCF. In the male fetuses, on day 14 of pregnancy the junction between the mesonephric (wolffian) duct and the UGS was located away from the junction between the rectum and the UGS. On day 18 of pregnancy the ejaculatory duct was located between the urinary bladder and the rectourethral fistula. The results of our experiment clearly show the embryologic relationship between the RF and the GUT with high ARA. The anomalous communication between the UGS and the rectum may interfere with normal caudal migration along the dorsal wall of the UGS at the junction between the UGS and the mesonephric or paramesonephric duct.