Crystal structure of beta-amylase from Bacillus cereus var. mycoides at 2.2 A resolution

The crystal structure of beta-amylase from Bacillus cereus var. mycoides was determined by the multiple isomorphous replacement method. The structure was refined to a final R-factor of 0.186 for 102,807 independent reflections with F/sigma(F) > or = 2.0 at 2.2 A resolution with root-mean-square deviations from ideality in bond lengths, and bond angles of 0.014 A and 3.00 degrees, respectively. The asymmetric unit comprises four molecules exhibiting a dimer-of-dimers structure. The enzyme, however, acts as a monomer in solution. The beta-amylase molecule folds into three domains; the first one is the N-terminal catalytic domain with a (beta/alpha)8 barrel, the second one is the excursion part from the first one, and the third one is the C-terminal domain with two almost anti-parallel beta-sheets. The active site cleft, including two putative catalytic residues (Glu172 and Glu367), is located on the carboxyl side of the central beta-sheet in the (beta/alpha)8 barrel, as in most amylases. The active site structure of the enzyme resembles that of soybean beta-amylase with slight differences. One calcium ion is bound per molecule far from the active site. The C-terminal domain has a fold similar to the raw starch binding domains of cyclodextrin glycosyltransferase and glucoamylase.

The usefulness of pharmacokinetic modulating chemotherapy (UFT plus 5FU) in the treatment of unresectable colorectal carcinomas

This study was performed to improve the prognosis of unresectable (primary non-curative and recurrent) colorectal carcinoma by using pharmacokinetic modulating chemotherapy (PMC), a combination of oral UFT and continuous venous 5FU infusion. The subjects were 120 patients who were prospectively selected for this study. The patients selected PMC or alternative treatment. Fifty-six patients received PMC. The PMC group received 200-400 mg/body/ day UFT orally 5-7 days per week and 600 mg/m2/24 h 5FU infusion once a week. PMC markedly improved the median survival period (26.6 months vs. 9.2 months P<0.000001). This significant improvement as observed in unresectable primary colorectal carcinoma (P=0.0003), recurrent tumors (P<0.00001), local extension (P=0.01), lung metastases (P=0. 03), liver metastases (P=0.0001), and peritoneal seedings (P=0.02). One of 56 patients who received PMC developed grade 4 toxicity. PMC significantly improved the prognosis of unresectable colorectal carcinoma which has a low survival rate. PMC also indicated tolerable compliance and cost effectiveness.

Transanal mucosectomy using an ultrasonically activated scalpel for ulcerative colitis

We describe herein our technique of using an ultrasonically activated scalpel (Harmonic Scalpel [HS]) to simplify the procedure of anorectal mucosectomy for ulcerative colitis (UC). This technique was successfully employed to perform restorative proctocolectomy and ileoanal anastomosis (IAA) in ten patients with UC. By using the HS, thermal injury of the internal anal sphincter was avoided during mucosectomy, and we were able to dissect the inflamed mucosa sharply without causing bleeding. HS reduced the operative time and blood loss compared with the traditional forceps-coagulation technique. These results indicate that the introduction of this new scalpel will facilitate an increase in the number of cases of mucosectomy for IAA.

Possible development of idiopathic sclerosing encapsulating peritonitis

We report a rare case of idiopathic sclerosing encapsulating peritonitis (SEP). During a laparotomy before undergoing a distal gastrectomy with Billroth II reconstruction for early gastric cancer, the patient was found to have a membranous encapsulation wrapping each small bowel loop, unlike peritoneal encapsulation or typical SEP. He had complained of persistent heartburn, distension and diarrhea for 2 months in the post-operative course. The second laparotomy, which was performed to improve prolonged transit, revealed typical SEP with a thick and fibrotic membrane that encased the small bowel entirely. Stripping of the sclerosing encasing membrane, separation of the adherent loops of the proximal small bowel, and Braun's anastomosis were performed. The patient complained of epigastric fullness and diarrhea after he was relieved from the complete bowel obstruction for 45 days post-operatively. Trimebutine maleate was administrated 5 months after the second operation and this markedly improved his symptoms. This case might reflect the developmental process of idiopathic SEP. In addition, the use of a motility regulator may improve symptoms related to the abnormal intestinal motility by this disease.

Massive pleural effusion and ascites resulting from esophagectomy with extensive lymphadenectomy for cancer of the abdominal esophagus

Chylothorax is an uncommon but well recognized complication of esophagectomy. We present the case of a 57 year-old man with squamous cell carcinoma of the abdominal esophagus who underwent subtotal esophagectomy by right thoracotomy. Post-operatively, the volume of pleural effusion from the right chest was increased (1600-2000 ml/day). The effusion was straw colored, not changing to milky after meals. The characteristics and composition of the pleural fluid were similar to those of chyle. We therefore treated this patient using methods for treatment of chylothorax, conservatively, by administration of OK-432 and minocycline/hydrochloride into the pleural cavity from the chest tube with success. We discuss the pathophysiology of this unusual condition and its treatment.

Marginal adaptation of commercial compomers in dentin cavity

The dentin cavity adaptation and setting characteristics of four commercial compomers were evaluated by measuring the wall-to-wall contraction gap width in the cylindrical dentin cavity and measuring the compressive strength for a maximum of 14 days after setting. The dentin cavity wall was pretreated by the dentin adhesives according to each manufacturer's instructions or the experimental contraction gap-free dentin bonding system. Complete marginal integrity was obtained in only one compomer and two resin composites which were combined with the experimental dentin bonding system. The compressive strength of two resin composites and two compomers ten minutes after setting was comparable to that after 14 days which indicated that the compomers exhibited setting characteristics as rapidly as the resin composite. It was concluded that a high efficacy dentin bonding system is required for commercial compomers to prevent gap formation during irradiation caused by the rapid setting shrinkage.

Effects of pharmacokinetic modulating chemotherapy using oral UFT and continuous venous 5FU infusion on the prognosis of irradiated rectal carcinomas with p53 overexpression

We previously found that patients with irradiated rectal carcinomas with p53 overexpression had poor prognoses after radical resection. In the present study, we attempted to improve the prognosis by the introduction of adjuvant chemotherapy. We administered pharmacokinetic modulating chemotherapy, based on the concept that the benefit of a continuous venous 5-fluorouracil (5FU) infusion can be potentiated by low-dose oral UFT, a combination of 1-(2-tetrahydrofuryl)-5-fluorouracil (tegafur) and uracil at a molar ratio of 1:4. Forty-two of 107 patients examined between January 1992 and December 1997 with an irradiated rectal carcinoma (39%) showed positive immunohistochemical staining for p53. Among them, 14 patients received adjuvant chemotherapy (CT group). The percentage of highly malignant tumors in the CT group was higher than that in the no-chemotherapy (NCT) group (n=28). However, the rate of cumulative local recurrence in the CT group was 0%, while that in the NCT group was 28.6% (p=0.0392). The distant recurrence rate in the CT group was also significantly lower than that in the NCT group (7.1% vs. 42.9%, p=0.0376). The cumulative 3-year survival rate was 100% in the CT group and 64.3% in the NCT group (p=0.0245). These results suggested that the antitumor property of 5FU enhanced by pharmacokinetic modulation might have a lethal effect on rectal tumors with a loss of the p53-related apoptosis pathway. These preliminary findings are encouraging for the treatment of rectal cancers with possible poor prognosis.

Magnetic resonance imaging in the diagnosis of jejunal leiomyoblastoma

We report a case of large leiomyoblastoma of the jejunum. The sagittal views in pre-operative magnetic resonance imaging (MRI) indicated that a cystic tumor with solid component was present, sequential from the small bowel. We suspected a smooth muscle tumor of the small bowel, but did not rule out the malignancy. The operative diagnosis was smooth muscle tumor of the proximal jejunum, and partial resection of the small bowel was performed. The pathological examination revealed benign leiomyoblastoma of the jejunum without metastasis. MRI contributed to the pre-operative diagnosis of the origin of this rare tumor, in a non-invasive fashion.

Usefulness of bipolar scissors for total colectomy

PURPOSE

Total colectomy is frequently used in colorectal surgery. We evaluated the usefulness of bipolar scissors in this operation.

METHODS

Twenty patients with ulcerative colitis underwent total colectomy at Hyogo College Hospital. Bipolar scissors were used in ten randomly chosen colectomies. The resected major vessels of the colonic mesentery were stained by hematoxylin and eosin. The bursting pressure of the artery weld was measured with a water-filled, open-tip catheter.

RESULTS

Both number of ligations and operating time were reduced by use of bipolar scissors. The cut edge of the major artery was occluded by the weld created, with a mean bursting pressure of 213 (range, 175-250) mmHg.

CONCLUSION

Use of bipolar scissors was safe and had the advantage of shortening the operating time by decreasing the number of clamping and ligating procedures.

Neural coding of 3D features of objects for hand action in the parietal cortex of the monkey

In our previous studies of hand manipulation task-related neurons, we found many neurons of the parietal association cortex which responded to the sight of three-dimensional (3D) objects. Most of the task-related neurons in the AIP area (the lateral bank of the anterior intraparietal sulcus) were visually responsive and half of them responded to objects for manipulation. Most of these neurons were selective for the 3D features of the objects. More recently, we have found binocular visual neurons in the lateral bank of the caudal intraparietal sulcus (c-IPS area) that preferentially respond to a luminous bar or place at a particular orientation in space. We studied the responses of axis-orientation selective (AOS) neurons and surface-orientation selective (SOS) neurons in this area with stimuli presented on a 3D computer graphics display. The AOS neurons showed a stronger response to elongated stimuli and showed tuning to the orientation of the longitudinal axis. Many of them preferred a tilted stimulus in depth and appeared to be sensitive to orientation disparity and/or width disparity. The SOS neurons showed a stronger response to a flat than to an elongated stimulus and showed tuning to the 3D orientation of the surface. Their responses increased with the width or length of the stimulus. A considerable number of SOS neurons responded to a square in a random dot stereogram and were tuned to orientation in depth, suggesting their sensitivity to the gradient of disparity. We also found several SOS neurons that responded to a square with tilted or slanted contours, suggesting their sensitivity to orientation disparity and/or width disparity. Area c-IPS is likely to send visual signals of the 3D features of an object to area AIP for the visual guidance of hand actions.

Effect of site directed mutagenesis in the CMGCC region of the alpha-subunit on immunoreactive human thyrotropin

The cDNA of the common alpha-subunit of human glycoprotein hormone was mutated by site directed mutagenesis in the CMGCC region composed of cysteine-methionine-glycine-cysteine-cysteine (position 28-32). The cDNA of wild-type human thyrotropin (hTSH) beta-subunit and that of wild-type or mutant common alpha-subunits were co-transfected into COS-I cells. The concentration of hTSH determined by two immunoradiometric assay systems was detectable in culture media of COS-I cells transfected with wild-type (CMGCC) and a mutant (CRGCC) alpha-subunits but not four other mutants (YMGCC) (CMRCC) (CMACC) (CMDCC). The present data with the other studies on wild-type or mutant glycoprotein hormones support our hypothesis that an amino acid motif of "C-X-G-X-C" in the common alpha-(CMGCC in human) and beta-(CAGYC in human) subunits play an important role in biosynthesis of glycoprotein hormones in all species.

Folding motifs induced and stabilized by distinct cystine frameworks

Bioactive peptides of different sources and biological functionalities, like endothelins, sarafotoxins, bee and scorpion venom toxins, contain a consensus cystine framework, Cys-(X)1-Cys/Cys-(X)3-Cys, which has been found to induce and stabilize a homologous folding motif named the cystine-stabilized alpha-helix (CSH). This is composed of an alpha-helical segment spanning the Cys-(X)3-Cys sequence portion that is crosslinked by two disulfide bridges to the sequence portion Cys-(X)1-Cys, itself folded in an extended beta-strand type structure. Search for sequence homologies of peptides and proteins in the SWISS-PROT and PDB data banks provided additional multiple examples of this type of cystine framework in serine proteinase inhibitors, in insect and plant defense proteins, as well as in members of the growth factor family with the cystine-knot. A comparative analysis of the known 3D-structures of these peptides and proteins confirmed that the presence of this peculiar cystine framework leads in all cases to a high degree of local structural homology that consists of the CSH motif, except for the cystine-knot, of the superfamily of the growth factors. In this case the cyclic structure formed by the parallel cysteine connectivities of Cys-(X)1-Cys/Cys-(X)3-Cys framework is penetrated by a third disulfide bond with formation of a concatenated knot, and the two disulfide-bridged peptide chains Cys-(X)1-Cys and Cys-(X)3-Cys are located in beta-strands. Conversely, peptides and proteins containing Cys-(X)m-Cys/Cys-(X)n-Cys cystine frameworks that differ from m/n = 1/3 were found to fold only sporadically into local alpha-helical structures.

The effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients with type 2 diabetes

OBJECTIVE

The present study was undertaken to reveal the effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients.

SUBJECTS AND METHODS

Seven obese men with Type 2 diabetes (OBDM) and seven healthy young men (HY) participated in this study. The glucose infusion rate (GIR) was determined by glucose clamp procedure at an insulin infusion rate of 40 mU m-2 min-1 (plasma insulin concentrations: 700-800 pmol l-1). Confirming stabilized GIR, a 30-min bicycle exercise was performed during the glucose clamp which was continued for 120 min after exercise.

RESULTS

Average GIR in OBDM for last 30 min prior to exercise were significantly lower than HY (28.3 +/- 1.7, 47.4 +/- 1.8 mumol kg-1 min-1 respectively, P < 0.05). GIR abruptly increased during exercise and gradually decreased after exercise to the nadir almost at the time from 30 to 60 min in recovery period in both groups. GIR in OBDM, however, gradually increased significantly over pre-exercise levels (P < 0.05), following exercise and reached the same levels compared to HY after 80 min of recovery period.

CONCLUSION

These results indicated that in obese Type 2 diabetes, 30 min of low intensity bicycle exercise significantly enhances the lower level of insulin-induced glucose uptake shortly after exercise and might be useful for the treatment of post-prandial hyperglycemia.

The relationship between stapling doughnuts: characteristics and functional results after total gastrectomy

BACKGROUND/AIMS

The objective of this study was to determine whether the thickness of the esophageal doughnut is related to postoperative results in total gastrectomy.

METHODOLOGY

Thirty-eight total gastrectomy patients were studied, including 18 who underwent jejunal pouch reconstruction and 20 who did not have pouch reconstruction. We used the Proximate-ILS circular stapler, with purse-string suturing at the cut end of the esophagus performing only the mucosal layer manually in all cases. We divided the esophageal doughnuts after stapling into two groups: Group A: doughnut involving muscle tissue of 0-25% of the esophageal circumference; Group B: doughnut involved muscle tissue of 25-100% of the esophageal circumference. Reflux scores and the scintigraphic reflux index were determined.

RESULTS

No significant difference was found between the two groups in reflux score or scintigraphic reflux index.

CONCLUSIONS

These findings indicate that the degree of postoperative reflux esophagitis was not affected by the amount of the muscular layer included in the esophageal doughnut. Continuity, and not variability of the degree of involved muscle in the esophageal doughnut, is an important factor at the time of stapling.

Simulation of S2-state multiline EPR signal in oriented photosystem II membranes: structural implications for the manganese cluster in an oxygen-evolving complex

High-quality angular-dependent spectra of multiline electron paramagnetic resonance (EPR) signals from the S2-state Mn cluster in a photosynthetic oxygen-evolving complex (OEC) were obtained for partially oriented photosystem (PS) II membranes, and the magnetic structure of the Mn cluster has been studied by simulation analysis. The angular-dependent multiline spectra were simulated by taking into account the anisotropic properties of both hyperfine tensors of intrinsic Mn ions and g-tensor of the cluster in a tetranuclear model. The best-fit parameters for the simulation indicate that (a) the oxidation state of the S2-state Mn cluster is Mn(III, IV, IV, IV), (b) the electronic orbital configuration of the Mn(III) ion is (dpi)3[dz2(sigma))]1, (c) the effective g-tensor of the Mn cluster and the hyperfine tensor of the Mn(III) ion are axially symmetric, and their principal z-axes are nearly collinear each other, and (d) the z-axis of the dz2 orbital of the Mn(III) ion and the normal of the thylakoid membrane are at an angle of 50.1 +/- 1.8 degrees. The results are compatible with those of the oriented XAFS study [Mukerji, I., et al. (1994) Biochemistry 33, 9712-9721], and indicate that the O-O vector of the putative di-mu-oxo bridged Mn(III)-Mn(IV) dimer unit in the Mn cluster tilts by 43-56 degrees with respect to the normal of thylakoid membrane. A model of the arrangement of the di-mu-oxo bridged Mn(III)-Mn(IV) unit with respect to the thylakoid membrane is proposed.

A lipoprotein lipase activator, NO-1886, improves endothelium-dependent relaxation of rat aorta associated with aging

Endothelial function is closely related to development of atherosclerosis and is impaired with aging. The novel compound NO-1886, 4-diethoxyphosphorylmethyl-N-(4-bromo-2-cyanophenyl)benzamid e, is a lipoprotein lipase activator and its long term administration protects against the development of experimental atherosclerosis in animals. The aim of this study was to ascertain whether NO-1886 ameliorates the impaired endothelium-dependent relaxation of rat aorta associated with aging. NO-1886 (50 mg/kg p.o.) was administered to 7-month old rats for 3 months. Plasma lipid, glucose and insulin levels in old control rats (10 months of age) were significantly higher than those of young rats (2 months of age). NO- 1886 decreased plasma triglyceride levels (old rats, 233+/-10 mg/dl; old rats + NO-1886, 172+/-16 mg/dl, P < 0.01) and increased plasma high density lipoprotein (HDL) cholesterol level (old rats, 72+/-6 mg/dl; old rats + NO-1886, 142+/-6 mg/dl, P < 0.001) in old rats, but had no effects on plasma glucose or insulin. The endothelium-dependent relaxation of the thoracic aorta caused by histamine was significantly impaired in old rats (% relaxation at 10(-5.5) M histamine: young rats 25.4+/-3.1%; old rats 14.1+/-1.9%, P < 0.01), an effect completely prevented by NO-1886 (old rats + NO-1886; 22.8+/-2.8%, P < 0.05 vs. old rats). In contrast, NO-1886 showed no effect on the endothelium-independent relaxation by sodium nitroprusside. These results indicate that NO-1886 improves impaired endothelium-dependent relaxation of rat aorta associated with aging, possibly by correcting lipid metabolism.

The prediction of the prognosis for rectal carcinoma down-staged by pre-operative radiotherapy by transrectal ultrasonography

BACKGROUND

We attempted to determine whether the results of transrectal ultrasonography (TRUS) could provide any prognostic information about patients with rectal carcinoma treated with pre-operative radiotherapy (RT).

METHODS

Ninety-eight patients with rectal carcinoma were treated with pre-operative RT and radical surgery. We categorized the TRUS results with respect to TNM classification before the RT (Pre-RT staging), those after the RT (Post-RT staging), and the results of the pathological examination (Post-OP staging). We analysed the associations among these three stagings, and the survival time of the patients.

RESULTS

The prevalence of under T2-stage (TNM classification) in the pre-RT staging was significantly lower than that in both the Post-RT and Post-OP staging. The number of tumours diagnosed as T4 stage in both the Post-RT and Post-OP staging was significantly lower than that before irradiation. The survival periods of the patients with tumours remaining as T4 after radiation were significantly shorter than those of the patients diagnosed as having T4 tumours at the Pre-RT staging (Pre-RT versus Post-RT, p = 0.019; Pre-RT versus Post-OP, p = 0.030). These results suggested that radio-insensitive residual cells might associate with the poor prognosis.

CONCLUSION

We could predict the possible prognosis in rectal carcinoma patients treated with pre-operative radiotherapy before operation by TRUS.

The actions of a novel lipoprotein lipase activator, NO-1886, in hypertriglyceridemic fructose-fed rats

High circulating fasting and prandial triglyceride levels are associated with both insulin resistance and the development of cardiovascular disease. The aim of this investigation was to study the effects of NO-1886, a novel lipoprotein lipase (LPL) activator, on triglyceride levels, fat oxidation, and glucose tolerance in fructose-fed rats, a hypertriglyceridemic model of insulin resistance. Adult male Wistar rats were fed for 4 weeks with a high-starch diet or a high-fructose diet without and with NO-1886 (50 mg x kg[-1] x d[-1] orally). Fructose feeding increased plasma triglyceride levels, an effect that was ameliorated by NO-1886 treatment (week 1/week 4: starch-fed, 2.4 +/- 0.1/2.8 +/- 0.2 mmol/L; fructose-fed, 3.6 +/- 0.5/5.5 +/- 0.5; fructose + NO-1886, 2.7 +/- 0.2/3.6 +/- 0.3). The mean 24-hour respiratory quotient (RQ) was significantly lower in the fructose + NO-1886 group compared with fructose-fed rats, indicating increased oxidation of fat. Fructose feeding elevated liver triglyceride levels by 74% (P < .01), an effect not altered by NO-1886. Red and white quadriceps hindlimb muscle triglyceride levels were not different between groups. Glucose tolerance (intravenous test in long-term cannulated rats) was mildly deteriorated and fasting insulin and glucose levels were elevated in fructose-fed rats, effects which were ameliorated by NO-1886. In conclusion, in the fructose-fed rat model of hypertriglyceridemia and insulin resistance, addition of a LPL activator reduced circulating triglyceride levels without causing increased muscle triglyceride accumulation or deterioration in glucose tolerance. LPL activators may prove to be a fruitful avenue to explore in the search for new therapeutic agents in the treatment of dyslipidemias and insulin resistance.

Length measuring device for transrectal ultrasonography of anorectal lesions

We, herein, describe an attachable measuring device for transrectal ultrasonography. It is a useful piece of equipment for measuring the precise length of a lesion and for fixing the position of the transducer under examination for sphincteric dynamics.

The representation of visual salience in monkey parietal cortex

When natural scenes are viewed, a multitude of objects that are stable in their environments are brought in and out of view by eye movements. The posterior parietal cortex is crucial for the analysis of space, visual attention and movement. Neurons in one of its subdivisions, the lateral intraparietal area (LIP), have visual responses to stimuli appearing abruptly at particular retinal locations (their receptive fields). We have tested the responses of LIP neurons to stimuli that entered their receptive field by saccades. Neurons had little or no response to stimuli brought into their receptive field by saccades, unless the stimuli were behaviourally significant. We established behavioural significance in two ways: either by making a stable stimulus task-relevant, or by taking advantage of the attentional attraction of an abruptly appearing stimulus. Our results show that under ordinary circumstances the entire visual world is only weakly represented in LIP. The visual representation in LIP is sparse, with only the most salient or behaviourally relevant objects being strongly represented.

Gastroesophageal reflux after distal gastrectomy: possible significance of the angle of His

OBJECTIVE

We investigated whether the angle of His influences gastroesophageal reflux after distal gastrectomy.

METHODS

Thirty-eight patients having distal gastrectomy and 10 controls underwent upper gastroesophageal fluoroscopy to measure the angle of His, and gastroesophageal reflux was assessed by scintigraphy. The association between scintigraphic reflux and the angle of His was then evaluated.

RESULTS

In distal gastrectomy patients with and without reflux symptoms, the angle was 108.82 +/- 21.88 degrees and 96.07 +/- 13.25 degrees, respectively; it was 74.14 +/- 10.85 degrees in the controls. The angle was significantly larger in the patients than in the controls (p < 0.01). In addition, the angle in the symptomatic gastrectomy group tended to be larger than in the asymptomatic group. The angle was also significantly larger in patients with a scintigraphic reflux index > or =6% than in those with an index <6% (p < 0.05).

CONCLUSIONS

These findings suggest that the angle of His plays a role in reflux after distal gastrectomy and that the severity of reflux may be estimated by measuring this angle.

Involvement of the nervous system in the control of glucose uptake in contracting hindlimb muscle in the rat

To probe into the possibility of neural control of glucose uptake in contracting peripheral skeletal muscle, rats were divided into two groups: one group is the "normal" (N) group in which the nervous system is intact, and the other is the "denervation" (D) group in which all nerves innervating the hindlimb were cut. The immediate changes in blood glucose (BG) and plasma insulin (PI) levels were measured at the commencement and termination of hindlimb muscle contraction induced with electrical stimulation of the sciatic nerve (distal part in D group). BG in N group temporarily but significantly decreased (p < 0.01) immediately after starting the stimulation, while BG in D group remained unchanged. And the difference between the changes in BG observed in 2 groups was significant (p < 0.03). PI did not change in either group during the sample period. On the other hand, PI temporarily but significantly decreased (p < 0.03) immediately after terminating the stimulation in both groups. The results suggest that the nervous system has some role in controlling glucose uptake in contracting peripheral muscle, at least in the early stage of contraction, that some feedback loop, including the central nervous system, is considered essential for the control, and that some local mechanism promotes an increase in insulin binding to receptors on muscle cells immediately after terminating the contraction.