Genetic variation in the gene encoding calpain-10 is associated with type 2 diabetes mellitus

Type 2 or non-insulin-dependent diabetes mellitus (NIDDM) is the most common form of diabetes worldwide, affecting approximately 4% of the world's adult population. It is multifactorial in origin with both genetic and environmental factors contributing to its development. A genome-wide screen for type 2 diabetes genes carried out in Mexican Americans localized a susceptibility gene, designated NIDDM1, to chromosome 2. Here we describe the positional cloning of a gene located in the NIDDM1 region that shows association with type 2 diabetes in Mexican Americans and a Northern European population from the Botnia region of Finland. This putative diabetes-susceptibility gene encodes a ubiquitously expressed member of the calpain-like cysteine protease family, calpain-10 (CAPN10). This finding suggests a novel pathway that may contribute to the development of type 2 diabetes.

Mutations in the hepatocyte nuclear factor-1alpha gene in maturity-onset diabetes of the young (MODY3)

The disease non-insulin-dependent (type 2) diabetes mellitus (NIDDM) is characterized by abnormally high blood glucose resulting from a relative deficiency of insulin. It affects about 2% of the world's population and treatment of diabetes and its complications are an increasing health-care burden. Genetic factors are important in the aetiology of NIDDM, and linkage studies are starting to localize some of the genes that influence the development of this disorder. Maturity-onset diabetes of the young (MODY), a single-gene disorder responsible for 2-5% of NIDDM, is characterized by autosomal dominant inheritance and an age of onset of 25 years or younger. MODY genes have been localized to chromosomes 7, 12 and 20 (refs 5, 7, 8) and clinical studies indicate that mutations in these genes are associated with abnormal patterns of glucose-stimulated insulin secretion. The gene on chromosome 7 (MODY2) encodes the glycolytic enzyme glucokinases which plays a key role in generating the metabolic signal for insulin secretion and in integrating hepatic glucose uptake. Here we show that subjects with the MODY3-form of NIDDM have mutations in the gene encoding hepatocyte nuclear factor-1alpha (HNF-1alpha, which is encoded by the gene TCF1). HNF-1alpha is a transcription factor that helps in the tissue-specific regulation of the expression of several liver genes and also functions as a weak transactivator of the rat insulin-I gene.

A genome-wide search for human non-insulin-dependent (type 2) diabetes genes reveals a major susceptibility locus on chromosome 2

Non-insulin-dependent (type 2) diabetes mellitus (NIDDM) is a common disorder of middle-aged individuals characterized by high blood glucose levels which, if untreated, can cause serious medical complications and lead to early death. Genetic factors play an important role in determining susceptibility to this disorder. However, the number of genes involved, their chromosomal location and the magnitude of their effect on NIDDM susceptibility are unknown. We have screened the human genome for susceptibility genes for NIDDM using non-and quasi-parametric linkage analysis methods in a group of Mexican American affected sib pairs. One marker, D2S125, showed significant evidence of linkage to NIDDM and appears to be a major factor affecting the development of diabetes mellitus in Mexican Americans. We propose that this locus be designated NIDDM1.

The Pro12 -->Ala substitution in PPAR-gamma is associated with resistance to development of diabetes in the general population: possible involvement in impairment of insulin secretion in individuals with type 2 diabetes

The allele frequencies for a Pro12-->Ala substitution in peroxisome proliferator-activated receptor-gamma differ among ethnic groups, and its relationship with diabetes and associated diseases is controversial. The prevalence of this polymorphism and its effects on clinical characteristics have now been evaluated with a large number of Japanese individuals with type 2 diabetes (n = 2,201) and normal control subjects (n = 1,212) recruited by 10 institutions located in seven different cities in Japan. The allele frequency for the Ala12 variant was significantly lower in the type 2 diabetic group than in the control group (2.39 vs. 4.13%, P = 0.000054). However, compared with subjects without the Ala12 variant, the diabetic subjects with this variant exhibited a significantly higher serum concentration of total cholesterol (P = 0.001), manifested a reduced capacity for insulin secretion as evaluated by homeostasis model assessment (P = 0.007), and tended to possess a higher level of HbA1c. These data suggest that the Ala12 variant is associated with a reduced risk for the development of diabetes in the general population, but that it may be also a risk factor for insulin deficiency and disease severity in individuals with type 2 diabetes.

Significant evidence for linkage of febrile seizures to chromosome 5q14-q15

Febrile seizures (FSs) represent the most common form of childhood seizure. In the Japanese population, the incidence rate is as high as 7%. It has been recognized that there is a significant genetic component for susceptibility to this type of seizure. Two putative FS loci, FEB1 (chromosome 8q13-q21) and FEB2 (chromosome 19p), have been mapped. Furthermore, a mutation in the voltage-gated sodium (Na(+))-channel beta1 subunit gene ( SCN1B ) at chromosome 19q13.1 was identified in a family with a clinical subset, termed generalized epilepsy with febrile seizures plus (GEFS(+)). These loci are linked to some large families. In this study, we conducted a genome-wide linkage search for FS in one large family with subsequent linkage confirmation in 39 nuclear families. Significant linkage was found at D5S644 by multipoint non-parametric analysis using GENEHUNTER ( P = 5.4 x 10(-6)). Estimated lambda(s)at D5S644 was 2.5 according to maximum likelihood analysis. Significant linkage disequilibria with FS were observed at the markers D5S644, D5S652 and D5S2079 in 47 families by transmission disequilibrium tests. These findings indicate that there is a gene on chromosome 5q14-q15 that confers susceptibility to FSs and we call this gene FEB4.

Normal hip joint contact pressure distribution in single-leg standing--effect of gender and anatomic parameters

A practical and easy-to-use analysis technique that can study the patient's hip joint contact force/pressure distribution would be useful to assess the effect of abnormal biomechanical conditions and anatomical deformities on joint contact stress for treatment planning purpose. This technique can also help to establish the normative database on hip joint contact pressure distribution in men and women in different age groups. Twelve anatomic parameters and seven biomechanical parameters of the hip joint in a normal population (41 females, 15 males) were calculated. The inter-parameter correlations were investigated. The pressure distribution in the hip joint was calculated using a three-dimensional discrete element analysis (DEA) technique. The 3D contact geometry of the hip joint was estimated from a 2D radiograph by assuming that the femoral head and the acetabular surface were spherical in shape. The head-trochanter ratio (HT), femoral head radius, pelvic height, the joint contact area, the normalized peak contact pressure, abductor force, and the joint contact force were significantly different between men and women. The normalized peak contact pressure was correlated both with acetabular coverage and head-trochanter ratio. Change of abductor force direction within normal variation did not affect the joint peak contact pressure. However, in simulated dysplastic conditions when the CE angle is small or negative, abductor muscle direction becomes very sensitive in joint contact pressure estimation. The models and the results presented can be used as the reference base in computer simulation for preoperative planning in pelvic or femoral osteotomy.

Formation and lateralization of internal representations underlying motor commands during precision grip

The capability to store and retrieve weight-related information from a lift to scale the force output during a subsequent lift was examined in 10 healthy adults and 50 children (age 2-10 years), as well as a 22-year-old patient with corpus callosum agenesis. Subjects lifted a test object between the thumb and index finger while the isometric fingertip forces were measured. The results suggest that both healthy children and adults can transfer weight-related information between the right and left hand, although a lateralization was found. Also, the storage and retrieval of weight-related information appears to be a dynamic process dependent on both previous sensory information and knowledge of future movements. Late maturation of interhemispheric connections and asymmetric loss of some information during the transfer between hemispheres suggest a lateralization of the internal representation. The patient with a corpus callosum agenesis supported this hypothesis.

Vascularised fibular grafts. An experience of 102 patients

The results and complications of 104 vascularised fibular grafts in 102 patients are presented. Bony union was ultimately achieved in 97 patients, with primary union in 84 (84%). The mean time to union was 15.5 weeks (8 to 40). In 13 patients, primary union was achieved at one end of the fibula and secondary union at the other end. In these patients, the mean time to union was 31.1 weeks (24 to 40). Five patients failed to achieve union, with a resultant pseudarthrosis (3 patients) or amputation (2 patients). There were various complications. Immediate thrombosis occurred in 14 cases. In two of 23 patients with osteomyelitis, infection recurred at two and six months after surgery, respectively. Both patients had active osteomyelitis less than one month before the operation. Bony infection occurred in a patient with a synovial sarcoma of the forearm one year after surgery. In 15 patients, 19 fractures of the fibular graft occurred after bony union, all except one within one year after union. In patients in whom an external fixator had been used, fracture occurred soon after its removal. Union was difficult to achieve in cases of congenital pseudarthrosis of the tibia. Appropriate alignment of the fibular graft is an important factor in preventing stress fracture. The vascularised fibula should be protected during the first year after union. Postoperative complications at the donor site included transient palsy of the superficial peroneal nerve in three patients, contracture of flexor hallucis longus in two and valgus deformity of the ankle in three. Vascularised fibular grafts are useful in the reconstruction of massive bony defects. We believe that meticulous preoperative planning, including choosing which vessels to select in the recipient and the type of fixation devices to use, and care in the introduction of the vascularised fibula, can improve the results and prevent complications.

Biomechanical analysis of limited intercarpal fusion for the treatment of Kienböck's disease: a three-dimensional theoretical study

Although several types of intercarpal fusion have been advocated for the treatment of Kienbock's disease, the clinical outcome of each procedure is still inconclusive. The joint load and ligament tension based on a three-dimensional model were measured to determine which intercarpal fusion procedures unload the lunate and whether they alter the force transmission through the entire wrist joint. Ten theoretical models of wrists were used to simulate three different operative procedures: capitate-hamate fusion, scapho-trapezial-trapezoidal fusion, and scaphocapitate fusion. A discrete element analysis technique was used to perform these investigations. The joint force and ligament tension of normal wrists and of simulated operative procedures were calculated according to the deformation of each spring element, simulating the articular cartilage and the carpal ligaments. Scaphocapitate and scapho-trapezial-trapezoidal fusions significantly decreased the joint force at the radiolunate joint and the lunocapitate joint compared with the intact wrist. In contrast, these fusions significantly increased this value at the radioscaphoid joint in comparison with the intact wrist. In the midcarpal joint, scaphocapitate fusion also increased the joint force at the scapho-trapezial-trapezoidal joints and at the triquetral-hamate joint, whereas scapho-trapezial-trapezoidal fusion increased it at the scapho-capitate joint. Capitate-hamate fusion yielded no significant changes of the joint forces through the entire wrist joint. In the analysis of ligament tension, scaphocapitate and scapho-trapezial-trapezoidal fusions significantly decreased the tension only in the dorsal scapholunate ligament. These findings demonstrate that scaph-ocapitate and scapho-trapezial-trapezoidal fusions are effective in decompressing the lunate. By contrast, capitate-hamate fusion is ineffective in reducing lunate compression. Although scaphocapitate and scapho-trapezial-trapezoidal fusions are recommended for the treatment of Kienbock's disease, clinicians should consider that the increase of force transmission through the radioscaphoid and the midcarpal joints may lead to early degenerative changes after these procedures have been performed.

Impaired sensory-motor integration during grasping in writer's cramp

Six subjects with writer's cramp and six healthy control subjects were examined while lifting a small instrumented object with variable weight and friction using the precision grip. The isometric grip and load forces were sampled at 400 Hz and stored in a flexible laboratory computer system for later analysis. Quantitative measurement of vibration and temperature sensibility showed normal sensory perception in the writer's cramp subjects. They exhibited an impaired programming of the grip-lift force co-ordination, while the ability to generate unimodal force-rate trajectories and to characterize the pattern of the force output according to memory representations of weight and friction of the object were intact. The capacity to terminate quickly the programmed grip force in lifts erroneously programmed too high was impaired. Writer's cramp subjects also employed excessive grip force during the static phase of the lift, and some patients had a short grip force latency after sudden unpredicted load increases, indicating a disinhibited spinal reflex response. The results indicate an impaired capacity in writer's cramp subjects to integrate sensory information in the motor programming and force regulation during precision grip tasks, despite a normal sensibility.

Vascularised fibular grafts

The results and complications of 104 vascularised fibular grafts in 102 patients are presented. Bony union was ultimately achieved in 97 patients, with primary union in 84 (84%). The mean time to union was 15.5 weeks (8 to 40). In 13 patients, primary union was achieved at one end of the fibula and secondary union at the other end. In these patients, the mean time to union was 31.1 weeks (24 to 40). Five patients failed to achieve union, with a resultant pseudarthrosis (3 patients) or amputation (2 patients).

There were various complications. Immediate thrombosis occurred in 14 cases. In two of 23 patients with osteomyelitis, infection recurred at two and six months after surgery, respectively. Both patients had active osteomyelitis less than one month before the operation. Bony infection occurred in a patient with a synovial sarcoma of the forearm one year after surgery. In 15 patients, 19 fractures of the fibular graft occurred after bony union, all except one within one year after union. In patients in whom an external fixator had been used, fracture occurred soon after its removal. Union was difficult to achieve in cases of congenital pseudarthrosis of the tibia. Appropriate alignment of the fibular graft is an important factor in preventing stress fracture. The vascularised fibula should be protected during the first year after union.

Postoperative complications at the donor site included transient palsy of the superficial peroneal nerve in three patients, contracture of flexor hallucis longus in two and valgus deformity of the ankle in three.

Vascularised fibular grafts are useful in the reconstruction of massive bony defects. We believe that meticulous preoperative planning, including choosing which vessels to select in the recipient and the type of fixation devices to use, and care in the introduction of the vascularised fibula, can improve the results and prevent complications.

Liver and kidney function in Japanese patients with maturity-onset diabetes of the young

OBJECTIVE

Heterozygous mutations in the transcription factors hepatocyte nuclear factor (HNF)-1 alpha, HNF-1 beta, and HNF-4 alpha are associated with maturity-onset diabetes of the young (MODY) and are believed to cause this form of diabetes by impairing pancreatic beta-cell function. The HNFs also play a central role in the tissue-specific regulation of gene expression in liver and kidney, suggesting that patients with MODY due to a mutation in HNF-1 alpha, HNF-1 beta, or HNF-4 alpha may exhibit abnormal liver or kidney function. Here, we have examined liver and kidney function in a series of Japanese patients with HNF-4 alpha/MODY1, HNF-1 alpha/MODY3, and HNF-1 beta/MODY5 diabetes.

RESEARCH DESIGN AND METHODS

Clinical and biochemical data were obtained from Japanese subjects with HNF-1 alpha, HNF-1 beta, and HNF-4 alpha diabetes. The clinical data included information on BMI, age at diagnosis, current treatment, and the presence and nature of any complications. The biochemical studies examined liver and kidney function and included measures of alanine and aspartate aminotransferase, gamma-glutamyl transpeptidase, blood urea nitrogen, creatinine, uric acid, total and HDL cholesterol, triglycerides, and 17 serum proteins.

RESULTS

The present age and duration of diabetes were similar in patients with HNF-1 alpha, HNF-1 beta, or HNF-4 alpha diabetes, as was the age at diagnosis of diabetes in the youngest generation. All subjects were lean. Of the subjects with HNF-1 alpha and HNF-4 alpha diabetes, 50% were treated with insulin, as were all three subjects with HNF-1 beta diabetes. Retinopathy was present in patients with each form of diabetes. None of the subjects with HNF-4 alpha diabetes had evidence of nephropathy, whereas 36% of the patients with HNF-1 alpha diabetes and 100% of those with HNF-1 beta diabetes showed diminished kidney function. The three subjects with HNF-1 beta diabetes also had abnormally high serum creatinine, uric acid, and blood urea nitrogen levels, which are consistent with impaired kidney function, and one of seven subjects with HNF-1 alpha diabetes had a mild elevation in creatinine and blood urea nitrogen levels. These values were within the normal range in the three patients with HNF-4 alpha diabetes. Although the HNFs play a role in regulating the expression of the genes for most, if not all, serum proteins, there was no decrease in the levels of any of the 17 serum proteins examined, and most were within or slightly above the normal range. Lipoprotein(a) [Lp(a)] levels were elevated in the three patients with HNF-4 alpha diabetes and in one patient with HNF-1 beta diabetes, and in a second patient with HNF-1 beta diabetes, Lp(a) was at the upper limit of normal.

CONCLUSIONS

The results indicate that as in white patients, MODY resulting from mutations in the HNF-1 alpha, HNF-1 beta, and HNF-4 alpha genes in Japanese patients may be a severe disease similar to classic type 2 diabetes. In addition, they suggest that patients with HNF-1 beta diabetes may be characterized by diminished kidney function and perhaps abnormal liver function. Further studies are needed to determine whether tests of liver and kidney function will be useful in the diagnosis and subclassification of MODY.

Chondroprotective effects of high-molecular-weight cross-linked hyaluronic acid in a rabbit knee osteoarthritis model

OBJECTIVES

We hypothesized that high-molecular-weight (MW) cross-linked (CL) hyaluronic acid (HA) improves joint lubrication and has an enhanced chondroprotective effect. We examined the histopathological changes and friction coefficients in osteoarthritic knee joints after injecting high-MW CL HA.

DESIGN

A bilateral anterior cruciate ligament transection (ACLT) model in 20 Japanese white rabbits was used. From week 5 after transection, low-MW HA (0.8 × 10(6) Da; HA80) or high-MW CL HA (6 × 10(6) Da; HA600) was injected weekly into 10 right knee for 3 weeks; normal saline (NS) was injected into the 10 left knee. A sham operation was undertaken to exclude spontaneous osteoarthritis (OA) in five knees. Results were evaluated with macroscopy, histopathology (Kikuchi's score), biomechanical testing, and rheological assessment of the joint fluid viscoelasticity. Statistical analysis was performed using one-way analysis of variance with a 95% confidence interval (CI) (P < 0.05).

RESULTS

The macroscopic findings showed severely damaged cartilage in 30% of the NS group and 20% of the HA80 and HA600 groups and intact cartilage in 100% of the sham group. The histological scores and friction coefficients of the HA600 group were significantly lower than those of the NS group (P = 0.007 and P = 0.002, respectively). Viscoelasticity measurements of the joint fluid showed no significant differences between the three treatment groups.

CONCLUSION

High-MW CL HA exerts potential chondroprotective effects and produces superior friction coefficients. Our results suggest that HA600 delays the progression of OA effectively and improves joint lubrication significantly.

Organization and partial sequence of the hepatocyte nuclear factor-4 alpha/MODY1 gene and identification of a missense mutation, R127W, in a Japanese family with MODY

Hepatocyte nuclear factor-4 alpha (HNF-4 alpha) is a member of the nuclear receptor superfamily, a class of ligand-activated transcription factors. A nonsense mutation in the gene encoding this transcription factor was recently found in a white family with one form of maturity-onset diabetes of the young, MODY1. Here, we report the exon-intron organization and partial sequence of the human HNF-4 alpha gene. In addition, we have screened the 12 exons, flanking introns and minimal promoter region for mutations in a group of 57 unrelated Japanese subjects with early-onset NIDDM/MODY of unknown cause. Eight nucleotide substitutions were noted, of which one resulted in the mutation of a conserved arginine residue, Arg127 (CGG)-->Trp (TGG) (designated R127W), located in the T-box, a region of the protein that may play a role in HNF-4 alpha dimerization and DNA binding. This mutation was not found in 214 unrelated nondiabetic subjects (53 Japanese, 53 Chinese, 51 white, and 57 African-American). The R127W mutation was only present in three of five diabetic members in this family, indicating that it is not the only cause of diabetes in this family. The remaining seven nucleotide substitutions were located in the proximal promoter region and introns. They are not predicted to affect the transcription of the gene or mRNA processing and represent polymorphisms and rare variants. The results suggest that mutations in the HNF-4 alpha gene may cause early-onset NIDDM/MODY in Japanese but they are less common than mutations in the HNF-1 alpha/MODY3 gene. The information on the sequence of the HNF-4 alpha gene and its promoter region will facilitate the search for mutations in other populations and studies of the role of this gene in determining normal pancreatic beta-cell function.

Linkage and association of febrile seizures to the IMPA2 gene on human chromosome 18

BACKGROUND

Febrile seizures (FSs) are the most common form of childhood seizures, and genetic factors play a role in susceptibility to FS.

OBJECTIVE

To identify novel loci and genes associated with susceptibility to FS.

METHODS

Study participants were the FS probands and family members of 59 Japanese nuclear families (223 members including 112 affected children). Forty-eight of these families had at least two affected children for which genome-wide linkage screening was carried out. The Genehunter software was used to perform nonparametric multipoint linkage analysis. Mutational and association analyses were conducted in all 59 Japanese FS families.

RESULTS

Genotyping data of 407 microsatellite markers suggested linkage of FSs to chromosome 18p11.2 (non-parametric linkage score = 3.68, p = 0.0001). This region includes the IMPA2 gene, which encodes myo-inositol monophosphatase (IMPase) 2. In the phosphatidylinositol-signaling pathway, IMPase is inhibited by lithium, which has a proconvulsant effect, and is stimulated by carbamazepine, an anticonvulsant. A systematic search was performed for mutations in IMPA2 in 24 unrelated randomly selected Japanese FS patients; seven variants were detected. Haplotype analysis revealed an association of a common haplotype in IMPA2 with FSs (p = 0.0009).

CONCLUSION

The authors found a novel locus on chromosome 18p11.2 for febrile seizures (FSs). IMPA2 is likely to be an FS susceptibility gene.

Mutations in the hepatocyte nuclear factor-1alpha/MODY3 gene in Japanese subjects with early- and late-onset NIDDM

Recent studies have shown that mutations in the hepatocyte nuclear factor (HNF)-1alpha gene are the cause of maturity-onset diabetes of the young type 3 (MODY3). We have screened 193 unrelated Japanese subjects with NIDDM for mutations in this gene: 83 with early-onset NIDDM (diagnosis at <30 years of age) and 110 with late-onset NIDDM (diagnosis > or = 30 years of age). All of the members of the latter group also had at least one sibling with NIDDM. The 10 exons, flanking introns, and promoter region were amplified using polymerase chain reaction and were sequenced directly. Mutations were found in 7 of the 83 (8%) unrelated subjects with early-onset NIDDM. The mutations were each different and included four missense mutations (L12H, R131Q, K205Q, and R263C) and three frameshift mutations (P379fsdelCT, T392fsdelA, and L584S585fsinsTC). One of the 110 subjects with late-onset NIDDM was heterozygous for the missense mutation G191D. This subject, who was diagnosed with NIDDM at 64 years of age, also had a brother with NIDDM (age at diagnosis, 54 years) who carried the same mutation, suggesting that this mutation contributed to the development of NIDDM in these two siblings. None of these mutations were present in 50 unrelated subjects with normal glucose tolerance (100 normal chromosomes). Mutations in the HNF-1alpha gene occur in Japanese subjects with NIDDM and appear to be an important cause of early-onset NIDDM in this population. In addition, they are present in about 1% of subjects with late-onset NIDDM.

A quantitative study of the progress of myelination in the rat central nervous system, using the immunohistochemical method for proteolipid protein

The temporal changes in intensity of myelination of the nervous pathways in 0 to 42-day-old Wistar rats were quantitatively analyzed by immunohistochemistry with anti-proteolipid protein and compared with that obtained by immunohistochemistry with anti-myelin basic protein. Immunohistochemistry was performed on paraffin-embedded tissue according to the standard ABC technique. Intensity of myelination was examined by an image analyzing system. We analyzed nine nervous pathways: corpus callosum, optic tract, internal capsule, spinal tract of the trigeminal nerve, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract, medial longitudinal fasciculus, and cuneate fasciculus. The presence of immunoreactive fibers for proteolipid protein (PLP) in the spinal tract of the trigeminal nerve, medial longitudinal fasciculus and cuneate fasciculus was noted on postnatal day 0. Those of the corpus callosum, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract and internal capsule were noted on day 7, and that of optic tract on day 14. The time required to reach the intensity of myelination of day 42 was day 14 for the cuneate fasciculus, day 21 for the spinal tract of the trigeminal nerve, inferior cerebellar peduncle and medial longitudinal fasciculus, day 28 for the optic and pyramidal tracts, day 35 for the corpus callosum and day 42 for the internal capsule and cerebellar white matter. The appearance of immunoreactive fibers for PLP was usually earlier than that for myelin basic protein (MBP) and the pattern of difference between PLP and MBP can be classified into three groups: (1) their time of appearance and progress are almost the same, as in the optic tract; (2) the appearance and progress of PLP occurs earlier than those of MBP, as in the pyramidal tract; (3) the appearance of PLP occurs earlier than that of MBP, but their progress is the same. Our findings revealed that the time of appearance and progress of myelination as measured by PLP are different among the nervous pathways, and that there is also a difference between PLP and MBP. This difference between PLP and MBP may indicate a functional difference between them.

Increased plasma endothelin in NIDDM patients with retinopathy

OBJECTIVE

To elucidate the significance of ET in diabetic microvascular disease.

RESEARCH DESIGN AND METHODS

We determined plasma levels of ir-ET-1 in 25 NIDDM patients without hypertension and/or renal dysfunction.

RESULTS

The plasma levels of ir-ET-1 in NIDDM patients with simple (n = 8) and proliferative (n = 8) retinopathy were 0.58 +/- 0.04 pM and 0.60 +/- 0.04 pM, respectively, which were significantly higher than those in normal, nondiabetic subjects (0.24 +/- 0.02 pM [n = 31]) and NIDDM patients without retinopathy (0.30 +/- 0.05 pM [n = 9]).

CONCLUSIONS

These results suggest that plasma ET-1 is related to diabetic microvascular disease.

Action tremor during object manipulation in Parkinson's disease

In previous studies of fingertip forces during precision grip in subjects with Parkinson's disease (PD), we observed regular oscillations in isometric force. The present study characterizes the nature of these oscillations. Fingertip forces were recorded from the index finger and thumb during precision grip-lifts with a 300 g and 900 g object in 10 subjects with PD and 20 healthy control subjects. Fourier analysis confirmed that all subjects with PD exhibited force oscillations with a clearly definable frequency (approximately 7-11 Hz). Five of these subjects also exhibited a second lower frequency peak (approximately 5 Hz). Approximately half of the 20 control subjects displayed a single frequency peak (approximately 8-12 Hz), which was generally lower in amplitude than in the subjects with PD (representing enhanced physiological tremor), whereas the remaining control subjects had low-amplitude, broad-based spectra (representing physiological tremor). The amplitude of the force oscillations was higher for lifts with the heavier object in both the control subjects and subjects with PD. L-Dopa resulted in a decreased tremor amplitude but did not influence the frequency. The force oscillations of the two opposing digits normal to the grip surfaces were in phase, whereas the oscillations tangential to the grip surfaces were often out of phase. The results suggest that the multipeaked force rate trajectories reported previously are caused by action tremor. The similarity of force oscillations in subjects with PD and healthy control subjects suggests common tremor-generating mechanisms and supports the notion that the parkinsonian action tremor (AT) is an exaggerated form of physiological tremor. These findings provide insight into the impaired hand function observed in individuals with PD.

Modification of the Sauvé-Kapandji procedure with extensor carpi ulnaris tenodesis

The Sauvé-Kapandji procedure is a useful treatment option for osteoarthritis of the distal radioulnar joint. Recent reports of a painful unstable proximal ulnar stump prompted us to develop a method of stabilizing the proximal stump of the ulna during the Sauvé-Kapandji procedure by using a half-slip of the extensor carpi ulnaris. Thirteen osteoarthritic wrists (8 primary and 5 traumatic) in 8 men and 5 women with an average age of 50 years were treated by this method. The length of the follow-up periods averaged 36 months. Pain improved in all patients after surgery but pain was elicited over 1 ulnar stump by direct pressure. Both pronation/supination and flexion/extension had statistically significant improvement with the exception of flexion. Grip strength improved in all wrists after surgery. Postoperative x-rays improved alignment in both coronal and lateral planes. Stabilization of the proximal ulnar stump associated with Sauvé-Kapandji procedure is a useful procedure to prevent an unstable ulnar stump in the treatment of osteoarthritis of the distal radioulnar joint.

Effects of bisphosphonate on matrix metalloproteinase enzymes in human periodontal ligament cells

BACKGROUND

The host response is a critical component in the pathogenesis of periodontitis. In fact, the clinical benefits associated with regulating the host response have been demonstrated in studies using several different classes of drugs. Biophosphates are one host-modulating class of drugs that has demonstrated this ability. These drugs are clinically effective at reducing bone resorption and have shown the ability to inhibit host degradative enzymes, specifically the matrix metalloproteinases (MMPs). Therefore, the purpose of this study was to investigate the regulatory effects of a bisphosphonate, tiludronate, on MMP levels and activity in human periodontal cells.

METHODS

MMP-1 and MMP-3 were assessed in cultured human periodontal ligament cells treated with a bisphosphonate, tiludronate. Reverse transcription-polymerase chain reaction was used to identify mRNA levels for both enzymes, and also for tissue inhibitors (TIMP-1). Enzyme immunoassay (EIA) and immunocytochemistry were used to assess MMP proteins in these cell cultures. Enzyme activity was assessed using FITC-conjugated substrates and quantitated using spectrophotofluorometry.

RESULTS

Tiludronate significantly inhibited both MMP-1 and MMP-3 activity in a concentration-dependent manner. A maximal reduction in activity of 35% was achieved for each of the enzymes at a 10(-4) M concentration. Tiludronate did not have a significant effect on the mRNA levels for MMP-1, MMP-3, or TIMP-1. Similarly, there were no effects noted for either MMP-1 or MMP-3 on the protein level.

CONCLUSIONS

This study demonstrates an inhibitory effect of tiludronate on the activity of both MMP-1 and MMP-3. These effects appear to occur without altering either mRNA or protein levels for these enzymes, supporting a possible mechanism of action that involves the ability of bisphosphonates to chelate cations from the MMPs. Furthermore, these results support the continued investigation of these drugs as potential therapeutic agents in periodontal disease.

Force distribution through the wrist joint in patients with different stages of Kienböck's disease: using computed tomography osteoabsorptiometry

The pattern of subchondral bone density has been considered to reflect the stress distribution that occurs under physiologic loading conditions. To determine the force distribution through the wrist joint with Kienböck's disease in living subjects, we applied a computed tomography osteoabsorptiometry and investigated the subchondral bone density pattern across the radio-carpal joint of 6 normal subjects and 10 patients suffering from Kienböck's disease (Lichtman's stage IIIA, 5 patients; stage IIIB, 5 patients). A single density maximum was found in each scaphoid and lunate fossa in all normal subjects. Among the subjects with Kienböck's disease, the current analysis demonstrated that the density maximum area significantly increased in the scaphoid fossa and decreased in the lunate fossa from stage IIIA to IIIB group. These findings indicate that the load is shifted away from the lunate to the scaphoid with the progression of Kienböck's disease in living subjects.