Indole alkaloids of Alstonia scholaris (L.) R. Br. alleviated nonalcoholic fatty liver disease in mice fed with high-fat diet

Alstonia scholaris (L.) R. Br (Apocynaceae) is a well-documented medicinal plant for treating respiratory diseases, liver diseases and diabetes traditionally. The current study aimed to investigate the effects of TA on non-alcoholic fatty liver disease (NAFLD). A NAFLD model was established using mice fed a high-fat diet (HFD) and administered with TA (7.5, 15 and 30 mg/kg) orally for 6 weeks. The biochemical parameters, expressions of lipid metabolism-related genes or proteins were analyzed. Furthermore, histopathological examinations were evaluated with Hematoxylin-Eosin and MASSON staining. TA treatment significantly decreased the bodyweight of HFD mice. The concentrations of low-density lipoprotein (LDL), triglyceride (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also decreased significantly in TA-treated mice group, accompanied by an increase in high-density lipoprotein (HDL). Furthermore, TA alleviated hepatic steatosis injury and lipid droplet accumulation of liver tissues. The liver mRNA levels involved in hepatic lipid synthesis such as sterol regulatory element-binding protein 1C (SREBP-1C), regulators of liver X receptor α (LXRα), peroxisome proliferator activated receptor (PPAR)γ, acetyl-CoA carboxylase (ACC1) and stearyl coenzyme A dehydrogenase-1 (SCD1), were markedly decreased, while the expressions involved in the regulation of fatty acid oxidation, PPARα, carnitine palmitoyl transterase 1 (CPT1A), and acyl coenzyme A oxidase 1 (ACOX1) were increased in TA-treated mice. TA might attenuate NAFLD by regulating hepatic lipogenesis and fatty acid oxidation.

[Evaluation of curative effect of VNG and VEMP in patients with severe sudden hearing loss]

Objective:To evaluate the relationship between vestibular function and curative effect in patients with severe sudden hearing loss.Method:The vestibular function of 79 patients with severe hearing loss was examined by video-nystagmography (VNG) and vestibular evoked myogenic potential (VEMP).Result:There were significant differences between the two test outcomes (P<0.01) in the severe group (27 cases). The effective rate of both VNG and VEMP normal group was 100%, the effective rate that both VNG and VEMP were abnormal was 41.7%. In the profound severe group (52 cases) there was also a significant difference between the two test results and the therapeutic effect (P<0.01). The effective rate of both VNG and VEMP normal group was 76.9%. The effective rate was 34.6% with both VNG and VEMP abnormal. There was no significant difference between hearing loss degree and curative effect.Conclusion:The VNG and VEMP examinations in patients with severe sudden hearing loss are valuable in evaluating the efficacy. Both VNG and VEMP were abnormal with the worst curative effect.

Improved anchoring nails: design and analysis of resistance ability : Tensile test and finite element analysis (FEA) of improved anchoring nails used in temporomandibular joint (TMJ) disc anchor

Background

Anchorage is one of the most important treatments for severe temporomandibular joint disorder (TMD). Anchoring nails have shown great success in clinical trials; however, they can break under pressure and are difficult to remove. In this study, we aimed to evaluate an improved anchoring nail and its mechanical stability.

Methods

The experiment consisted of two parts: a tensile test and finite element analysis (FEA). First, traditional and improved anchoring nails were implanted into the condylar cortical bone and their tensile strength was measured using a tension meter. Second, a three-dimensional finite element model of the condyles with implants was established and FEA was performed with forces from three different directions.

Results

The FEA results showed that the total force of the traditional and improved anchoring nails is 48.2 N and 200 N, respectively. The mean (±s.d.) maximum tensile strength of the traditional anchoring nail with a 3–0 suture was 27.53 ± 5.47 N. For the improved anchoring nail with a 3–0 suture it was 25.89 ± 2.64 N and with a 2–0 suture it was above 50 N. The tensile strengths of the traditional and improved anchoring nails with a 3–0 suture was significantly different (P = 0.033–< 0.05). Furthermore, the difference between the traditional anchoring nail with a 3–0 suture and the improved anchoring nail with a 2–0 suture was also significantly different (P = 0.000–< 0.01).

Conclusion

The improved anchoring nail, especially when combined with a 2–0 suture, showed better resistance ability compared with the traditional anchoring nail.

An instrument for measuring scintillators efficiently based on silicon photomultipliers

An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

Independent and joint effects of the IL-6 and IL-10 gene polymorphisms in pulmonary tuberculosis among the Chinese Han population

We investigated the association between interleukin (IL)-6 and IL-10 gene polymorphisms and the susceptibility to pulmonary tuberculosis (PTB). DNA samples were obtained from 191 Han Chinese patients with PTB and 191 healthy control subjects. IL-6 (-572, -174, -597) and IL-10 (-1082, -819) polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism. The IL-6 -572 C/C and IL-10 -819 T/T genotypes were observed less frequently in the case group than in the control group, with crude odds ratios of 0.591 [95% confidence interval (CI) = 0.381-0.917] and 0.401 (95%CI = 0.257-0.627), respectively. A significant association remained after adjusting for environmental factors in multivariate logistic analysis. The homozygote genotypes of IL-6 -572 and IL-10 -819 had an adjusted OR of 0.565 (95%CI = 0.356-0.898) and 0.341 (95%CI = 0.210-0.553), respectively. These results indicate that the mutant heterozygote IL-10 -1082 A/ G+G/G genotype and the homozygote IL-10 -819 T/T genotype have a combined effect on PTB. These results suggest that the IL-6 -572 C/C and IL-10 -819 T/T genotype polymorphisms are protective factors against PTB.

Stronger in vitro phagocytosis by monocytes-macrophages is indicative of greater pathogen clearance and antibody levels in vivo

Monocytes-macrophages are crucial players in specific and nonspecific immune responses to protect organisms from invasion of bacteria or viruses. In this study, monocytes in circulation from 2 lines of Silky and Starbro chickens with different disease resistance were separated and cultured in vitro. After identification with acridine orange (AO), Giemsa staining, and CD14 immunostaining, monocytes-macrophages were used for adherence and phagocytosis test. The overall percentages of adherence of Silky monocytes was 1.5 times greater than that of Starbro (P < 0.01), which were 26.85% +/- 8.24% and 18.34% +/- 8.15%, respectively (mean +/- SD). The monocytes-macrophages phagocytic index, phagocytic product, and percentage of phagocytosis in Silkies were greater than in Star-bros, respectively. The difference of phagocytic index was significant (P < 0.05), that is, 3.70 +/- 1.75 and 1.97 +/- 0.31, respectively (mean +/- SD). Then, 20 Silkies were divided into 2 groups according to phagocytic index: high phagocytic index (HPI) group and low phagocytic index (LPI) group, to study the relationship between phagocytic activity in vitro and pathogen clearance. After being challenged against Salmonella Pullorum C79-13, the Silky birds with HPI produced a 3-fold greater level of specific antibodies compared with those with LPI (P < 0.01), 50.21 +/- 6.67 and 16.85 +/- 4.52, respectively (mean +/- SD). In contrast to LPI birds, HPI birds shed less Salmonella Pullorum bacteria (P < 0.05), that is, 168.98 x 10(8) +/- 294.74 x 10(8) compared to 385.40 x 10(8) +/- 399.94 x 10(8) (mean +/- SD), and the shedding peak of Salmonella Pullorum in the test span appeared 4 d earlier. These results indicated that phagocytosis of monocytes-macrophages had strong effects on antibody titer and bacteria shedding postchallenge, which could be used to predict the disease resistance in animals.

Ventilation and hypoxic ventilatory responsiveness in Chinese-Tibetan residents at 3,658 m

When breathing ambient air at rest at 3,658 m altitude, Tibetan lifelong residents of 3,658 m ventilate as much as newcomers acclimatized to high altitude; they also ventilate more and have greater hypoxic ventilatory responses (HVRs) than do Han ("Chinese") long-term residents at 3,658 m. This suggests that Tibetan ancestry is advantageous in protecting resting ventilation levels during years of hypoxic exposure and is of interest in light of the permissive role of hypoventilation in the development of chronic mountain sickness, which is nearly absent among Tibetans. The existence of individuals with mixed Tibetan-Chinese ancestry (Han-Tibetans) residing at 3,658 m affords an opportunity to test this hypothesis. Eighteen men born in Lhasa, Tibet, China (3,658 m) to Tibetan mothers and Han fathers were compared with 27 Tibetan men and 30 Han men residing at 3,658 m who were previously studied. We used the same study procedures (minute ventilation was measured with a dry-gas flowmeter during room air breathing and hyperoxia and with a 13-liter spirometer-rebreathing system during the hypoxic and hypercapnic tests). During room air breathing at 3,658 m (inspired O2 pressure = 93 Torr), Han-Tibetans resembled Tibetans in ventilation (12.1 +/- 0.6 vs. 11.5+/- 0.5 l/min BTPS, respectively) but had HVR that were blunted (63 +/- 16 vs. 121 +/- 13, respectively, for HVR shape parameter A) and declined with increasing duration of high-altitude residence. During administered hyperoxia (inspired O2 pressure = 310 Torr) at 3,658 m, the paradoxical hyperventilation previously seen in Tibetan but not Han residents at 3,658 m (11.8 +/- 0.5 vs. 10.1 +/- 0.5 l/min BTPS) was absent in these Han-Tibetans (9.8 +/- 0.6 l/min BTPS). Thus, although longer duration of high-altitude residence appears to progressively blunt HVR among Han-Tibetans born and residing at 3, 658 m, their Tibetan ancestry appears protective in their maintenance of high resting ventilation levels despite diminished chemosensitivity.

Are Tibetans better adapted?

Evidence is reviewed from our recent (1987-1991) investigations which demonstrate better high-altitude adaptation among Tibetans than in acclimatized newcomers or other lifelong high-altitude residents. Characteristics of oxygen transport contributing to the Tibetans' remarkable exercise performance are described.

Increased vital and total lung capacities in Tibetan compared to Han residents of Lhasa (3,658 m)

Larger chest dimensions and lung volumes have been reported for Andean high-altitude natives compared with sea-level residents and implicated in raising lung diffusing capacity. Studies conducted in Nepal suggested that lifelong Himalayan residents did not have enlarged chest dimensions. To determine if high-altitude Himalayans (Tibetans) had larger lung volumes than acclimatized newcomers (Han "Chinese"), we studied 38 Tibetan and 43 Han residents of Lhasa, Tibet Autonomous Region, China (elevation 3,658 m) matched for age, height, weight, and smoking history. The Tibetan compared with the Han subjects had a larger total lung capacity [6.80 +/- 0.19 (mean +/- SEM) vs 6.24 +/- 0.18 l BTPS, P less than 0.05], vital capacity (5.00 +/- 0.08 vs 4.51 +/- 0.10 1 BTPS, P less than 0.05), and tended to have a greater residual volume (1.86 +/- 0.12 vs 1.56 +/- 0.09 1 BTPS, P less than 0.06). Chest circumference was greater in the Tibetan than the Han subjects (85 +/- 1 vs 82 +/- 1 cm, P less than 0.05) and correlated with vital capacity in each group as well as in the two groups combined (r = 0.69, P less than 0.05). Han who had migrated to high altitude as children (less than or equal to 5 years old, n = 6) compared to Han adult migrants (greater than or equal to 18 years old, n = 26) were shorter but had similar lung volumes and capacities when normalized for body size. The Tibetans' vital capacity and total lung capacity in relation to body size were similar to values reported previously for lifelong residents of high altitude in South and North America. Thus, Tibetans, like North and South American high-altitude residents, have larger lung volumes. This may be important for raising lung diffusing capacity and preserving arterial oxygen saturation during exercise.

Decreased ventilation and hypoxic ventilatory responsiveness are not reversed by naloxone in Lhasa residents with chronic mountain sickness

Persons with chronic mountain sickness (CMS) hypoventilate and are more hypoxemic than normal individuals, but the cause of the hypoventilation is unclear. Studies of 14 patients with CMS and 11 healthy age-matched control subjects residing in Lhasa, Tibet, China (3,658 m) were conducted to test the hypothesis that hypoventilation, blunted hypoxic ventilatory responsiveness (HVR), and hypoxic ventilatory depression of CMS were due to increased endogenous opioid production. Patients with CMS compared with control subjects exhibited hypoventilation (end-tidal carbon dioxide pressure [PETCO2] = 36.6 +/- 1.0 versus 31.5 +/- 0.5 mm Hg, p less than 0.05), lower tidal volume (VT = 0.54 +/- 0.02 versus 0.61 +/- 0.02 ml BTPS, p less than 0.05), blunted HVR (shape parameter A = 17 +/- 8 versus 114 +/- 22 mm Hg/L BTPS/min, p less than 0.05), and a depressant effect of ambient hypoxia on ventilation (delta PETCO2 with acute hyperoxia = -3.5 +/- 0.5 versus -1.0 +/- 0.6 mm Hg, p less than 0.05). Reduced forced expiratory volume in 1 s to vital capacity ratios (FEV1/VC) and a higher proportion of cigarette smokers in the group of patients with CMS compared with control subjects suggested that at least some patients with CMS had mild airway obstructive lung disease. Naloxone infusion (0.14 mg/kg) to six patients with CMS did not change resting VT, PETCO2, HVR, or SaO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Greater maximal O2 uptakes and vital capacities in Tibetan than Han residents of Lhasa

Maximal O2 uptake provides an index of the integrated functioning of the O2 transport system. Whether lifelong high altitude residents have greater maximal exercise capacities than acclimatized newcomers is of interest for determining whether years to generations of high altitude exposure influence maximal O2 uptake and, if so, what components of O2 transport are involved. We studied 16 Tibetan lifelong residents of Lhasa, Tibet, China (3658 m) and 20 Han ("Chinese") 8 +/- 1 year residents of the same altitude who were matched for age, height, weight and lack of exercise training. At maximal effort, the Tibetans compared to the Hans had greater O2 uptakes (51 +/- 1 vs 46 +/- 1 ml STPD.min-1.(kg bw)-1, P less than 0.05), exercise workloads (177 +/- 5 vs 155 +/- 6 watts, P less than 0.05), minute ventilations (149 +/- 6 vs 126 +/- 4 IBTPS/min, P less than 0.01) and O2 pulse (15.2 +/- 0.4 vs 13.3 +/- 0.5 ml O2 consumption/heart beat, P less than 0.05). Equally high heart rates were present at maximal effort (191 +/- 3 vs 187 +/- 3 beats/min, P = NS), supporting the likelihood that true maxima were achieved in both groups. The greater minute ventilation in the Tibetans resulted from greater tidal volume and the greater maximal tidal volume correlated positively with the resting vital capacity. We concluded that the Tibetans achieved a higher maximal O2 uptake than the Hans, implying an increased capacity for O2 transport to the working muscle.

Prevention of myocardial reperfusion injury with free radical scavengers. An experimental study

The changes in endogenous superoxide dismutase (ESOD) during myocardial ischemia and reperfusion and the efficacy of oxygen free radical scavengers in myocardial protection were investigated in an isolated heart model connected with the recirculating nonpulsatile perfusion circuit. Subjected to a 2-hour period of global ischemia (27 C), the heart was reperfused with 37 C oxygen diluted auto-blood for 60 minutes. Superoxide dismutase plus catalase was added into the cardioplegic solution and reperfusates. ESOD activity was measured by pyrogallol method. The results of the experiment showed that ESOD activity after ischemia and reperfusion was decreased and the addition of oxygen free radical scavengers (SOD and CAT) to the cardioplegic solution and the reperfusates greatly reduced the leakage of myocardial enzymes, coronary vascular resistance, and the ultrastructural damages of the myocardium. These results suggest that the use of SOD and CAT may inhibit myocardial reperfusion injury by scavenging oxygen-derived free radicals.

Circular dichroism of bovine serum albumin in divalent salt solutions

The circular dichroism of bovine serum albumin in divalent salt solutions was investigated. The salts selected were magnesium chloride and calcium chloride. Their effects on the secondary and tertiary structures of the protein were compared with that of lithium chloride. It is well known that the elements Ca, Mg, and Li have many properties in common. The results show the similarity of their ions in the capacity of deforming protein, in spite of their characteristic pharmacological functions.

Diabetic thoracic radiculopathy: electrodiagnostic study

We investigated the diagnostic value of electromyographic (EMG) examination of the anterior abdominal wall muscles (AWMS) in thoracic radiculopathy and compared it with examination of thoracic paraspinal muscles (TPSM). Technically, examination of AWMS was much easier compared to TPSM. In eight patients with thoracic diabetic radiculopathy at the level of T7-T12, AWMS was abnormal in all and was considered to be diagnostic, whereas AWMS was normal in diabetic lumbar radiculopathy, patients with diabetes mellitus without radiculopathy, patients with unspecified gastrointestinal pain, and patients with musculoskeletal-type back pain. We conclude that EMG evaluation for possible thoracic radiculopathy should include examination of AWMS, and if abnormal, would be of great diagnostic help in patients with unspecified gastrointestinal symptoms.

Mitral valve prolapse in myotonic dystrophy

Forty-three patients with myotonic dystrophy (MyD) and 43 age- and sex-matched controls were prospectively evaluated for mitral valve prolapse (MVP) using both cardiac auscultation and echocardiography (ECHO). Prevalence of MVP was significantly increased in MyD patients when using either abnormal auscultation plus abnormal ECHO (23.3%, P less than 0.02) or abnormal ECHO alone (30%, P less than 0.01) as diagnostic criteria for MVP. Frequency of MVP was even more increased in patients with a thin, flat chest compared with patients with normal physical appearance (P less than 0.007). These findings are in support of the concept that the increased frequency of MVP in neuromuscular disorders is likely due to geometrical changes of the heart caused by thorax deformities, rather than structural changes of the mitral valve. For this reason, MVP in MyD probably belongs to the entity of so-called benign, secondary MVP. This is further supported by the absence of symptoms of "systemic" complications of MVP in our patient population.

Myotonic dystrophy: obstetric and neonatal complications

Myotonic dystrophy is a relatively common disorder. Since the clinical expression is highly variable, diagnosis is often made only after the birth of an infant with severe congenital myotonic dystrophy. Seven such cases are described. A history of obstetric complications was present in the six multiparous mothers. Neither the neonatal features nor the pregnancy complications are specific, but their combinations should suggest the diagnosis, which can be confirmed by neurologic evaluation of the infant's mother.

Distal ulnar neuropathy. Clinical and electrophysiologic aspects

Nine patients with distal ulnar neuropathy were studied. Weakness of the hand muscles was the only abnormality in six patients; abnormal sensation was present in two patients. The cause was known in seven patients: chronic "occupational" nerve compression occurred in three meat packers and two long-distance bicyclists--acute blunt trauma to the palm of the hand in two patients. Our study indicates that electromyographic abnormalities in distal ulnar neuropathy are more variable than reported. The electromyographic findings indicated predominant axonal degeneration of motor nerve fibers, contrasting also to electromyographic abnormalities seen in entrapment neuropathies. The reasons for these differences are discussed.

Distal ulnar neuropathy in meat packers. An occupational disease?

Distal ulnar neuropathy at the wrist level was observed in three meat packers. The diagnosis was confirmed electromyographically, by follow-up, and with surgical exploration. Compression neuropathy of the distal ulnar nerve has been a well-recognized occupational hazard and is cause by chronic and repeated compression of the ulnar nerve at the level of Guyon's canal; pathogenetic mechanisms differ from those observed in the more common carpal tunnel syndrome.

Study of binding of warfarin to serum albumins by high-performance liquid chromatography

The binding of warfarin to human serum albumin and bovine serum albumin, respectively, was studied by high-performance liquid chromatography (HPLC). Based upon the Hummel - Dreyer method, two techniques were developed: the internal calibration and the external calibration. The results obtained by the HPLC method and those obtained by the classical method (equilibrium dialysis) were compared. The external calibration method seems to be superior to others for its simplicity, speed and convenience.

Hypertrophic form of peroneal muscular atrophy (PMA): unusual nerve conduction results

A family with a hypertrophic form of peroneal muscular atrophy (PMA) was studied with typical clinical and electrophysiological abnormalities in the propositus and her child. The propositus' father was asymptomatic and slowing of nerve conduction velocities was limited to the peroneal nerves. Actual parentage was confirmed by 22 different serologic and electrophoretic marker systems.

Distribution of electrical myotonia in myotonic muscular dystrophy

Twenty-five successive patients with myotonic dystrophy were examined to determine the anatomical distribution of electrical myotonia. Proximal and distal limb muscles and orbicularis oris and masseter muscles were examined. Electrical myotonia was present in all muscles examined in only 3 patients. Moreover, of the 15 muscles examined, none showed myotonic discharges in every patient, the highest individual muscle involvement being 96%.

Myotonic dystrophy: limited electromyographic abnormalities in 2 definite cases

Two women, aged 37 and 38, with definite myotonic dystrophy are presented. Neither patient had clinical myotonia although both experienced intermittent jaw tightness. Electromyographic (EMG) myotonia was seen only in the masseter muscle in one and in the masseter and flexor pollicis longus muscle in the other patient. The detection rate of EMG-myotonia in clinically normal heterozygotes increases if distal, proximal and cranial nerve innervated muscles are examined.

Autosomal recessive generalized myotonia

Two siblings and a first degree cousin of a consanguinous marriage were afflicted with recessive generalized myotonia (RGMy). All had muscle weakness which was particularly prominent after rest, thinning of the forearms, weakness of anterior compartment muscles, and muscular contractures. The first degree cousin was the most severely afflicted with congenital myotonia. Muscle biopsy and electromyography were consistent with a myopathy. Exercise after rest demonstrated a marked reduction in muscle membrane excitability in all patients.

Toe extensor weakness resulting from trivial athletic trauma. Report of three unusual cases

Three patients exhibited variable weakness of toe extensors after trivial injuries. The first patient suffered an acute, partial anterior compartment syndrome during a prolonged motorbike ride; the second a traction injury of the deep peroneal nerve while slipping during a racquetball game. The third patient developed a compression injury of the peroneal nerve on the basis of a generalized demyelinating polyneuropathy. The major clues for diagnosis and management came from electromyographic (EMG) examination.

Brachial plexopathy in patients with breast cancer: unusual electromyographic findings in two patients

2 patients with breast cancer developed progressive brachial plexopathy. The unusual electrographic finding in both patients was conduction block (neuropraxia) along the medial cord of the brachial plexus. The plexus was explored in 1 patient. Constrictive connective tissue or another source of nerve entrapment was not identified. The exact cause of the conduction block remains unclear; its presence neither indicates a good prognosis nor an indication for surgical exploration.

Notalgia paresthetica owing to compression neuropathy: case presentation including electrodiagnostic studies

A patient developed numbness over the upper part of his back, following prolonged bed rest in a supine position. Sweat test, clinical and electromyographic examination indicated neuropathies of the primary dorsal rami of the spinal nerves from T2 to T6. The literature is reviewed and anatomical considerations discussed.

Injection injury of the sciatic nerve: unusual anatomic distribution of nerve damage

Sciatic nerve damage by intragluteal injections tends to injure the peroneal nerve trunk more severely than the other components of the sciatic nerve. 2 patients with predominant or sole damage to the posterior tibial nerve trunk were observed. This distribution was documented electrophysiologically. Our cases are unusual and point to a wider spectrum of such injuries. It is also suggested that internal fibrosis of the nerve is of greatest importance as a pathogenetic mechanism in these injuries.

Diabetic thoracoabdominal neuropathy: clinical and electrodiagnostic features

Five diabetic patients developed upper back or abdominal pain associated with substantial weight loss in three. Electrophysiological evidence of associated thoracoabdominal somatic neuropathy was found in all cases. Signs of a generalized neuropathy were present in two patients, and four had asymmetrical proximal leg weakness. At least two have improved spontaneously. The syndrome is closely related to diabetic amyotrophy; it is probably more common than is recognized.

Structural studies on the succinylated bovine serum albumin

An analysis of succinylated bovine serum albumin showed that all of the 62 epsilon-amino groups of lysine residues, 13 hydroxyamino acid residues and 12 tyrosin residues were succinylated, but the succinylated tyrosines were later deacylated. Structural properties of the modified protein have been studied with circular dichroism and sedimentation velocity. At neutral pH (pH 7.60) and in a salt-free aqueous solution the modified protein is in an expanded form and its helical content is only 30% of that of unmodified protein. The increase of ionic strength restores the original conformation of the protein, whereas the increase of pH further disorganizes the structure of the protein. The results suggest that the electrostatic force alone is responsible for the compact structure of the protein molecule. The same mechanism is believed to underlie the effect of H3O+ and the effect of succinylation of the side chain groups on the conformation of bovine serum albumin.