Effective and selective stretching of the medial head of the gastrocnemius.

Muscle injury frequently occurs in the medial head of the gastrocnemius (MG), and stretching is used for treatment. However, there are no studies based on anatomical considerations and biomechanics. This study therefore examined the macroscopic anatomical structure of the triceps surae muscle to design an effective and selective MG stretching method, before quantitatively verifying that method by ultrasonography. The macroscopic anatomy was analyzed in 16 Japanese cadavers (25 legs). Based on the anatomical findings and the arrangement of fascicles in the MG, we concluded that ankle inversion might be advantageous for selective stretching of the tendon fiber bundles into which the MG inserts. We devised a method in which the limb was initially positioned with the knee joint in extension and the ankle joint in plantar flexion. Then, the ankle was dorsiflexed and inverted. The proposed method was compared with standard stretching and verified by ultrasonography in eight healthy adult males. This method effectively and selectively stretched the MG, producing a significantly decreased pennation angle and increased muscle fiber length. This method may be beneficial for preventing future injuries and may enhance the effect of therapy on the MG.

A KOH-collagenase digestion method for scanning electron microscopic studies of vascular smooth muscle fibers in the human heart.

The three-dimensional cytoarchitecture of smooth muscle fibers of human cardiac arterial vessels was studied by scanning electron microscopy after removal of extracellular connective tissue matrices with a KOH-collagenase digestion method. Arterioles with an outer diameter of 30-100 microm had a well-developed compact media consisting commonly of circularly oriented smooth muscle fibers. There were also arterioles with oblique or longitudinal muscle fibers in some places. In terminal arterioles with an outer diameter of less than 30 microm, muscle fibers became branched and commonly encircled the endothelial tube. There were some terminal arterioles covered with obliquely arranged smooth muscle fibers. The presence of the regional difference in arrangement of vascular smooth muscle fibers indicates the heterogeneity of blood flows in the level of cardiac microcirculation.

Length and width of the tendinous portion of the palmaris longus: a cadaver study of adult Japanese.

We examined 72 forearms of 36 cadavers to measure the length and width of the tendinous portion of the palmaris longus in adult Japanese. The palmaris longus muscles were absent in both arms in 1 cadaver and in a unilateral arm in 1 cadaver. Double palmaris longus muscles were found in 1 arm in another cadaver. Most cadavers had a typical palmaris longus muscle and tendon shape. The mean length and width of the tendons were 124.6 +/- 17.0 and 4.5 +/- 0.7 mm, respectively, in male specimens and 108.3 +/- 16.4 and 4.0 +/- 0.7 mm in female specimens, respectively. The mean lengths of the forearms were 240.0 +/- 12.6 mm in male specimens and 218.8 +/- 14.6 mm in female specimens. There was a statistically significant correlation between the lengths of the palmaris longus tendon and forearm. These results indicate that one can estimate the length of palmaris longus tendons before surgical intervention.

A rare muscular anomaly in the upper arm--the chondroepitrochlearis muscle with an aberrant type of the muscular arch of axilla.

A rare muscular anomaly was found in the right arm of a 92-year-old man at Nagoya University in 1995. The anomalous muscle had two heads, one ventral and one dorsal. The ventral head was a continuation of the abdominal part of the pectoralis major muscle, and the dorsal head arose from the lateral surface of the latissimus dorsi muscle. The two heads united at the medical surface of the upper third of the arm to form a common tendon, which descended on the medial surface of the upper arm parallel with a long tendon of the coracobrachialis muscle and attached to the medial epicondyle of the humerus. This anomalous muscle was supplied by the most caudal branch of the pectoral ansa (caudal pectoral nerve) and the intercostobrachial nerve (Th2). This pectoral nerve first innervated the ventral head, and next the greater part of the dorsal head. The intercostobrachial nerve (Th2) innervated a small part of the dorsal head. The present anomaly looked quite similar to the case reported by Yokoh as the coexistence of the chondroepitrochlearis and the dorsoepitrochlearis muscles. However, judging from the muscular origin, insertion and innervation, the ventral head was considered to be the chondroepitrochlearis muscle, whereas the dorsal head was not dorsoepitrochlearis muscle but an aberrant type of the muscular arch of axilla.

In vivo nuclear uptake of a vitamin D analog (OCT) in different tumor cell populations of FA-6 cancer xenograft in nude mice by receptor autoradiography.

1 alpha, 25-dihydroxyvitamin D3 [1 alpha, 25(OH)2D3] and its analogs have been shown to repress the production of parathyroid hormone-related peptide (PTHrP) in tumors, which is a major factor causing humoral hypercalcemia associated with various cancers. Since vitamin D analogs may be applicable to the treatment of cancer patients, the present study was undertaken to examine whether OCT, an analog with little calcemic activity, is incorporated into tumor tissues, and to identify cellular and subcellular sites of its specific uptake and retention. [26-3H]OCT was injected i.v. into nude mice inoculated with a human pancreatic carcinoma cell line (FA-6). At 1 hour after the injection, intracellular concentration of radioactivity was visualized by receptor (thaw-mount) autoradiography. The results indicate a heterogeneous distribution of radioactivity in nuclei of certain large cancer cells as well as in single or clustered small and elongated cells within the tumor, while connective tissue cells outside of the tumor remained free of nuclear labeling. The data suggest that OCT acts selectively at the genome of cancer cells during a certain maturational stage and also of a second population of small fibroblast-like cells that may have been transplanted with the tumor or are host-derived.

In vivo dose-related receptor binding of the vitamin D analogue [3H]-1,25-dihydroxy-22-oxavitamin D3 (OCT) in rat parathyroid, kidney distal and proximal tubules, duodenum, and skin, studied by quantitative receptor autoradiography.

1,25-Dihydroxy-22-oxavitamin D3 (OCT) is a new synthetic analogue of 1,25(OH)2D3 with a low calcemic effect. This study utilized quantitative receptor autoradiography to determine the dose-related receptor binding and saturation among the vitamin D target cells: parathyroid chief cells, kidney distal and proximal tubule epithelium, duodenal absorptive epithelium, and epidermal keratinocytes. Rats were injected with 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, or 16.0 microgram/kg bw of [26-3H]-OCT and sacrificed 1 hr afterwards. Then autoradiographs were prepared under identical conditions. In these target cells, nuclear uptake of radioactivity increased with dose and then achieved a plateau. However, their saturation doses showed differences: parathyroid chief cells 1-2 microgram duodenal absorptive epithelium, distal tubule epithelium, and epidermal keratinocytes 4-6 microgram proximal tubule epithelium 8 microgram (per kg bw). In contrast, in nontarget cells, such as liver and duodenal smooth muscle, radioactivity did not concentrate in the nuclei but increased in the cytoplasm with dose, without plateauing. These results provide the first information on the relative saturabilities of various target cell populations with a vitamin D ligand. Parathyroid chief cells required the relatively lowest receptor saturation dose. This suggests a high sensitivity and response to OCT treatment with related therapeutic potential for the regulation of parathyroid function.

In vivo metabolism of the vitamin D analog, 22-oxacalcitriol: evidence for side-chain truncation and 17-hydroxylation.

After intravenous administration of the vitamin D3 analog, 22-oxacalcitriol (OCT), to normal rats plasma metabolites were investigated by HPLC, GC-MS and LC-MS. Five side-chain oxidation metabolites, 24R(OH)OCT, 24S(OH)OCT, (25R)-26(OH)OCT, (25S)-26(OH)OCT and 24oxoOCT, were identified by comparison with the corresponding synthetic compounds. These side-chain oxidation metabolites were similar to those of calcitriol [1alpha,25(OH)2 vitamin D3] described previously. Besides these five metabolites, two unique side-chain cleavage metabolites, 20S(OH)-hexanor-OCT and 17,20S(OH)2-hexanor-OCT, were identified as main metabolites in plasma by GC-MS and LC-MS using a specific chemical reaction. Our studies suggest that OCT is extensively metabolized and circulates in blood as a number of metabolites as well as unchanged OCT. This metabolism includes both unique pathways of C23-O22 cleavage and 17-hydroxylation, in addition to the side-chain oxidation metabolites similar to those of 1alpha,25-(OH)2D3.

Metabolism of 2(R,S)-1,2-bis(nicotinamido)propane, a new agent with anti-vasospasm activity, in rats and rabbits.

1. The metabolic fate of the new Anti-vasospasm Substance (AVS), 2(R,S)-1,2-bis(nicotinamido)propane (CAS 79455-30-4), was studied using 14C-labelled drug in rats and rabbits by thinlayer chromatography, mass spectrometry and nuclear magnetic resonance. 2. More than 75% of the radioactivity was observed in the urine when 14C-AVS was given intravenously to rabbits and rats, showing that the major route of excretion of AVS and its metabolites is via the kidney. 3. Marked species differences were observed in the metabolism of AVS in rats and rabbits. In rabbits, the major metabolites were 6- or 6'-monopyridone (23.5% of dose), and there were a few minor metabolites such as the mono N- or N1-oxide of two pyridine rings. In rats, however, only approximately 5% of the radioactivity was due to metabolites, mainly the N-oxide. 4. Formation of AVS monopyridone by rabbit liver cytosol was much higher than in rats, and was markedly inhibited by the aldehyde oxidase inhibitor, menadione. The difference between rats and rabbits in oxidase activity giving the AVS monopyridone metabolite correlated well with that measured by the general assay method for aldehyde oxidase. These results suggest that the species difference in AVS metabolism between rats and rabbits is mainly due to the difference in aldehyde oxidase activity, which is involved in formation of the monopyridone.

Determination of 22-oxacalcitriol, a new analog of 1alpha,25-dihydroxyvitamin D3, in human serum by liquid chromatography-mass spectrometry.

A sensitive and specific liquid chromatographic-mass spectrometric assay has been developed for the determination of 22-oxacalcitriol (OCT), which is a new analog of 1alpha,25-dihydroxyvitamin D3. The analyte was isolated from serum by two solid-phase extraction steps on a C18 cartridge and NH2 cartridge. The recovery of OCT through two extraction steps was more than 90%. A related substance (ED-94), i.e. OCT with the side-chain shortened by one carbon, was used as an internal standard. Extracts were chromatographed on a C18 reversed-phase column interfaced to the electrospray ionization source. The mass spectrometer was operated in the positive-ion mode of selected reaction monitoring. The chromatographic run-time for one injection was less than 6 min. The intra- and inter-assay coefficients of variation for the lowest concentration examined (30 pg ml[-1]) were 9.83 and 10.67, respectively. And the analytical recovery of OCT added to serum was quantitative. Assay linearity was obtained in the range of 20-640 pg ml(-1).

Pharmacokinetics of erythropoietin in genetically anemic mice.

We examined the pharmacokinetics of recombinant human erythropoietin (rh-EPO) in genetically anemic mice (W/Wv genotype) to clarify its disposition mechanism in hematopoietic injury such as occurs in aplastic anemia. After rh-EPO was administered to W/Wv and control (+/+ genotype) mice once a day for 1 week at different doses, both the hematocrit (Hct) and tissue uptake clearance (CLup) of 125I-rh-EPO by spleen and bone marrow in the femur were estimated on the eighth day. The hematocrit increased on eighth day, depending on the dose administered. Compared with +/+ mice 10 times more rh-EPO was needed in W/Wv mice to produce an almost equivalent pharmacological effect. In +/+ mice, the CLup of 125I-rh-EPO by spleen increased to 4-fold that of controls after treatment with rh-EPO, 4.8 microg/kg, whereas that by bone marrow remained unchanged, irrespective of the dose administered. On the other hand, the increase in both the Hct and CLup in spleen was minimal in W/Wv mice. The CLup by bone marrow and spleen in both types of mice showed saturation with similar Km values (389-619 pM), comparable with the dissociation constant of the EPO receptor. In addition, the Hct correlated with the sum of the CLup by bone marrow and spleen in both types of mice, and the correlation lines were superimposable. These results suggest that the pharmacological receptors govern the saturable tissue uptake not only in normal mice but also in those that are anemic.

Differential time course of induction of 1alpha,25-dihydroxyvitamin D3-24-hydroxylase mRNA expression in rats by 1alpha,25-dihydroxyvitamin D3 and its analogs.

In order to investigate the in vivo mechanisms of target gene activation by vitamin D3 analogs, we compared the effects of two vitamin D3 analogs, 22-oxa-1alpha,25-(OH)2D3 (OCT) and 2beta (3-hydroxypropoxy) -1alpha,25-(OH)2D3 (ED-71) with that of 1alpha,25-(OH)2D3 on 1alpha,25-(OH)2D3 -24-hydroxylase[24(OH)ase] mRNA expression in the kidney and intestine of normal rats. In these experiments, all three compounds induced 24(OH)ase mRNA, but the time course of induction for each respective treatment was clearly different. OCT caused the most rapid onset of increased 24(OH)ase mRNA expression and its subsequent return to pre-injection levels. In marked contrast, ED-71 was the slowest to increase expression which was prolonged over that observed with the other compounds tested. These differences probably relate to the pharmacokinetic properties of these analogs, which are mainly generated by the affinity of analogs for the vitamin D-binding protein(DBP).

Inhibitory effect of heliantriol C; a component of edible Chrysanthemum, on tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin.

Two hydroxy taraxastane-type triterpenes, faradiol and heliantriol C, have been isolated from the ligulate flowers of Chrysanthemum morifolium Ramat. var. sinense Makino fa. esculentum Makino, the edible Chrysanthemum. These compounds showed strong inhibitory activity against 12-O-tetradecanoyl-phorbol-13-aetate (TPA)-induced inflammation in mice. At 0.2 µmol/mouse, these compounds markedly inhibited the promoting effect of TPA (1 µg/mouse) on skin tumor formation followed by 7,12-dimethylbenz[a]anthracene (50 µg/mouse).

Mechanism for the nonlinear pharmacokinetics of erythropoietin in rats.

The contribution of erythropoietin- (EPO) receptors in target tissues, such as bone marrow and spleen, to the nonlinear pharmacokinetics of recombinant human EPO (rh-EPO) was evaluated in rats. The total body clearance after i.v. administration of rh-EPO (0.2-5 microg/kg) decreased as the dose of rh-EPO increased, approaching a plateau at high doses. The uptake clearance of 125I-rh-EPO by the target tissues, bone marrow and spleen, exhibited clear saturation. The Km values ranged from 240 to 450 pM, which are comparable with the reported value for the dissociation constant of EPO binding to EPO-receptors (180 pM) in rat bone marrow cells. A single s.c. administration of a large dose of rh-EPO (1 microg/kg) caused a reduction in tissue uptake clearance of 125I-rh-EPO by bone marrow and spleen (down-regulation). Furthermore, repeated intravenous injection of rh-EPO caused up-regulation of the tissue uptake clearance of 125I-rh-EPO, especially by the spleen, in a dose-dependent manner. Hematopoietic parameters such as hematocrit and hemoglobin concentration were also increased by repeated rh-EPO treatment and significantly correlated with the sum of the tissue uptake clearances in bone marrow and spleen. These findings suggest that the pharmacological receptor could be an important factor in defining the nonlinear pharmacokinetics of rh-EPO.

Immunological response to repeated administration of recombinant human erythropoietin in rats: biphasic effect on its pharmacokinetics.

We studied changes in the pharmacokinetics of 125I-recombinant human erythropoietin (125I-rh-EPO) after repeated subcutaneous administration once a week for 4 weeks. The plasma level of trichloroacetic acid-precipitable radioactivity after the fourth administration of 125I-rh-EPO was minimal in 8 of 10 rats, whereas in the other two rats, the plasma level was almost the same or somewhat higher than that in control rats that had received the vehicle solution 3 times instead of the first three sequential administrations. Antibody against rh-EPO in serum was detected in all 10 rats receiving multiple administrations of 125I-rh-EPO. However, the binding capacity for 125I-rh-EPO in the latter two rats, assessed by an in vitro serum binding study, was lower than for the other eight rats, suggesting that the antibody level in these two was lower. The effect of intravenous preinjection of various volumes of anti-rh-EPO antiserum on the pharmacokinetics of 125I-rh-EPO was examined. The half-life in the beta-phase was prolonged at lower doses of antiserum. When the pretreatment dose of antiserum was further increased, the half-life in the beta-phase rather shortened and the total body clearance (CL(total) increased. These results suggest that repeated administration of rh-EPO induces the production of antibody against rh-EPO that affects the pharmacokinetics of rh-EPO in a biphasic manner; CL(total) was reduced when a small amount of antibody was produced, and CL(total) was increased when a large amount of antibody was produced.

Characteristics of mass spectrometric analyses coupled to gas chromatography and liquid chromatography for 22-oxacalcitriol, a vitamin D3 analog, and related compounds.

The characteristics of the mass spectra of vitamin D3 related compounds were investigated by GC-MS and LC-MS using 22-oxacalcitriol (OCT), an analog of 1,25-dihydroxyvitamin D3, and related compounds. Fragmentation during GC-MS (electron impact ionization) of TMS-derivatives of OCT and the postulated metabolites gave useful structural information concerning the vitamin D3-skeleton and its side-chain, especially with respect to the oxidation positions of metabolites. In contrast, few fragment ions were observed in LC-MS (atmospheric pressure chemical ionization), showing that LC-MS gave poor structural information, except for molecular mass. However, when comparing the signal-to-noise ratio (S/N) observed during GC-MS and LC-MS analysis for OCT in plasma extracts, the S/N in LC-MS was over ten-times greater than in GC-MS, possibly due to the low recovery on derivatization and thermal-isomerization in GC-MS. Furthermore, both the GC-MS and the LC-MS allowed the analysis of many postulated metabolites in a single injection without any prior isolation of target metabolites from biological fluids by LC. These results suggest that GC-MS and LC-MS analysis for vitamin D3 related compounds such as OCT each have unique and distinct advantages. Therefore, the complementary use of both techniques enables the rapid and detailed characterization of vitamin D3 related compounds.

Triterpene alcohols from the flowers of compositae and their anti-inflammatory effects.

Eleven tabular and nine ligulate flowers from 15 species of Compositae plants were investigated for their triterpene alcohol constituents. This led to the isolation and identification of 11 triterpene alcohols as follows: heliaol, taraxasterol, psi-taraxasterol, alpha-amyrin, beta-amyrin, lupeol, taraxerol, cycloartenol, 24-methyl-enecycloartanol, tirucalla-7,24-dienol and dammaradienol. The tabular flowers of Calendula officinalis, Carthamus tinctorius, Cosmos bipinnatus, Chrysanthemum morifolium, Helianthus annuus and Matricaria matricarioides showed a characteristic feature by containing helianol as the most predominant component (29-86%) in the triterpene alcohol fractions. The triterpene alcohols from Compositae flowers were evaluated with respect to their anti-inflammatory activity against 12-O-tetradecanoylphorbol-13-acetate-induced inflammation (1 microgram per ear) in mice. All of these showed marked inhibitory activity, and their 50% inhibitory dose was 0.1-0.8 mg per ear.

The 69-84 amino acid region of the parathyroid hormone molecule is essential for the interaction of the hormone with the binding sites with carboxyl-terminal specificity.

We evaluated the competitive inhibitory effect of intact PTH, the amino-terminal PTH(1-34) fragment, and a series of truncated carboxyl-terminal PTH fragments on the binding of internally 35S-labeled human PTH(1-84) ([35S]hPTH(1-84)) to osteoblastic cells (ROS 17/2.8), in order to identify the minimum and critical elements within the PTH molecule for the interaction with the binding sites specific for the carboxyl-terminal region of the hormone. When the amino-terminal region of the PTH molecule was truncated stepwise, hPTH(35-84), hPTH(53-84) and hPTH(69-84), but not hPTH(70-84), significantly inhibited the [35S]hPTH(1-84) binding. On the other hand, the simple deletion of the carboxyl-terminal glutamine at position 84 of hPTH(53-84) [hPTH(53-83)] resulted in blunting the inhibitory effect of the peptide on the [35S]hPTH(1-84) binding. Furthermore, hPTH(35-84), hPTH(53-84) and hPTH(69-84), but not hPTH(70-84) nor hPTH(53-83), augmented the inhibitory effect of the amino-terminal PTH fragment [hPTH(1-34)] on the [35S]hPTH(1-84) binding. Of special interest was that the combination of hPTH(1-34) and hPTH(35-84) reproduced the inhibitory effect of unlabeled hPTH(1-84) on the [35S]hPTH(1-84) binding, on an equimolar basis. The 69-84 region of the PTH molecule thus appears to be crucial for binding to the carboxyl-terminal specific binding sites for PTH in osteoblasts. The interaction of the amino-terminal and carboxyl-terminal regions of a PTH molecule with their own respective binding sites seemed to occur in a fairly independent manner.

Inhibitory effect of Di- and trihydroxy triterpenes from the flowers of compositae on 12-O-tetradecanoylphorbol-13-acetate-induced inflammation in mice.

Ten dihydroxy- and trihydroxy triterpenes, viz., four taraxastanes: faradiol, heliantriol B0, heliantriol C and arnidiol; two lupanes: calenduladiol and heliantriol B2; two oleananes: maniladiol and longispinogenin; and two ursanes: brein and uvaol, isolated from the nonsaponifiable lipids of the flower extracts of Compositae plants were evaluated with respect to their anti-inflammatory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. All the triterpenes were found to possess marked inhibitory activity. The 50% inhibitory dose of these compounds with respect to TPA-inflammation (1 microgram) was 0.03-0.2 mg/ear.

Inhibitory effect of taraxastane-type triterpenes on tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin.

Two taraxastane-type hydroxy triterpenes, taraxasterol and faradiol, isolated from the flowers of Compositae plants Cynara scolymus (artichoke) and Chrysanthemum morifilolium (chrysanthemum), respectively, showed strong inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. At 2.0 mumol/mouse, these compounds inhibited markedly the tumor-promoting effect of TPA (1 microgram/mouse) on skin tumor formation following initiation with 7,12-dimethylbenz[alpha]anthracene (50 micrograms/mouse).

[The courses and the segmental origins of the cutaneous branches of the thoracic dorsal rami].

It is described in many textbooks that the medial cutaneous branches (RCM) from the medial branches of the upper six thoracic dorsal rami supply the upper half of the back of the body, the lateral cutaneous branches (RCL) from the lateral branches of the lower six thoracic dorsal rami supply the lower half of it, and the area supplied by both branches is limited to a few segments. Unlike those descriptions, we had frequently observed RCL from the second or the third thoracic dorsal ramus penetrating the rhomboideus muscle during previous research concerning the double innervation of the superficial muscles of the back by both the ventral and the dorsal rami (Kumaki et al., 1984). To make clear the origin of the discrepancy between the description in the textbooks and our observations, we examined the segmental origins, the courses, and the distributions of both the medial and the lateral branches of the thoracic dorsal rami on 20 sides of 11 bodies dissected in the years 1986 and 1989. Consequently, RCL from the second thoracic dorsal ramus (Th 2) was observed in 25% of the cases and RCL from Th 3 and Th 4 were observed in 50% and in 70%, respectively. The highest segment of RCL was Th 2 in 25%, Th 3 in 25%, Th 4 in 35%, Th 6 in 10%, or Th 8 in 5%, and the mean was Th 3.65 +/- 1.53. On the other hand, the lowest segment of RCM was Th 6 (15%), Th 7 (35%), Th 8 (25%), Th 9 (15%), or Th 10 (10%), and the mean was Th 7.70 +/- 1.19. The mean number of the segments at which the dorsal ramus of the thoracic nerve sent both RCM and RCL was 4.55 +/- 1.50 (Max: 9 segments). Thus, we made clear that RCL from the upper thoracic nerves were commonly observed and that the number of segments sending both RCM and RCL was larger than hitherto described. The course of the upper RCL was bent at the points where the RCL penetrated the superficial muscles of the back forming a "Z"-shape, i.e., RCL changed its course from an infero-lateral to an infero-medial direction at the point of penetrating the rhomboid muscle and from an infero-medial to a lateral direction at the point of penetrating the trapezius muscle or the latissimus dorsi muscle. These directions might be associated with the development of the muscles. Sometimes RCL was sharply pulled in a medial direction by the trapezius muscle to penetrate the muscle near the median plane and appeared as RCM. Therefore, we supposed that the main reason why the upper RCL had been overlooked was because the complicated zigzag course of the RCL was damaged by the inadequate dissection or RCL was mistaken for the RCM. While the points where the cutaneous branches penetrated the superficial muscles were variable, the points where they penetrated the thoraco-lumbar fascia were relatively stable. This point of the RCM was generally near the tip of the spinal process of the same segmental number of the nerve, and the same point of RCL was generally at the gap between the longissimus and the iliocostal muscles in the intercostal space one segment lower than the segment of the RCL. The RCL from the last thoracic to the third lumbar dorsal rami communicated with one another to form a nerve plexus under the lumbo-dorsal aponeurosis, then penetrated that aponeurosis forming several nerve bundles, crossed over the iliac crest and supplied the hip skin as the superior cluneal nerves. Therefore, each bundle was not equivalent to each segment, but was composed of two or more segments.