Rate of hydrolysis of the phosphate esters of B vitamins is reduced by zinc deficiency: In vitro and in vivo.

Extracellular hydrolysis of the phosphate esters of B vitamins (B1, B2, and B6) is crucial for their cellular uptake and metabolism. Although a few zinc-dependent enzymes have been implicated in these processes, their exact mechanisms of action remain largely unknown. This study investigated the potential involvement of phosphate group hydrolyzing enzymes in the hydrolysis of B vitamin phosphate esters. We evaluated enzyme activity in membrane lysates prepared from cells transiently transfected with these enzymes or those endogenously expressing them. Specifically, we investigated how zinc deficiency affects the rate of hydrolysis of B vitamin phosphate esters in cellular lysates. Assessment of the activities of zinc-dependent ectoenzymes in the lysates prepared from cells cultured in zinc-deficient conditions and in the serum of rats fed zinc-deficient diets revealed that zinc deficiency reduced the extracellular hydrolysis activity of B vitamin phosphate esters. Furthermore, our findings explain the similarities between several symptoms of B vitamin and zinc deficiencies. Collectively, this study provides novel insights into the diverse symptoms of zinc deficiency and could guide the development of appropriate clinical strategies.

Reconstruction of Acute Patellar Tendon Rupture after Patellectomy.

Acute rupture of the knee extensor mechanism after patellectomy is extremely rare. We present the case of a patient with acute patellar tendon rupture who had undergone patellectomy 53 years before. Twelve days after the injury, the ruptured patellar tendon was repaired with end-to-end suture. Postoperatively, we splinted the knee for 6 weeks but permitted the patient to walk without limiting weight bearing at 1 week postoperatively. At one-year follow-up, the patient is able to move his knee almost full range of motion and the Lysholm knee score is 81. The patient is satisfied with the outcome. This is the first report to treat acute rupture of the patellar tendon in a patient who had undergone patellectomy. Although careful rehabilitation is required, end-to-end suture might be an adequate surgical procedure for acute rupture of the knee extensor mechanism after patellectomy.

Mid-term clinical results of primary total knee arthroplasty using metal block augmentation and stem extension in patients with rheumatoid arthritis.

BACKGROUND: Despite recent advancements in rheumatoid arthritis (RA) pharmacotherapy, surgeons still encounter severely damaged knees. The purpose of the present study was to analyze the mid-term clinical results of total knee arthroplasty (TKA) with metal block augmentation and stem extension. METHODS: A total of 26 knees in 21 patients who underwent primary TKA with metal block augmentation and stem extension were retrospectively reviewed. All patients with a mean age of 63 years had RA for a mean duration of 15 years. Functional and radiographic results as well as complications were evaluated at the mean follow-up period of 6 years after TKA. Eight knees were lost follow-up after the two-year evaluation. RESULTS: Tibial bone defects with average depth of 19 mm were preoperatively recognized in all 26 knees. The postoperative joint line was reconstructed on average 11 mm above the fibular head using average thickness of 11 mm tibial inserts and 9 mm metal blocks with stem extension. Significant improvements (p < 0.05 for all comparisons) were observed postoperatively in maximum extension angle from -10° to -1°, range of motion from 101 ° to 115 °, and Knee Society Score (knee score/function score) from 35/18 to 90/64. Non-progressive radiolucent lines beneath the metal block and osteosclerotic changes around the medullary stem were found in 16 knees (62%) and 14 knees (54%), respectively. There was two failures (8%): fragile supracondylar femur fractures and knee instability. No knees showed any radiographic implant loosening, dislocation, polyethylene insert breakage, peroneal palsy, or infection. CONCLUSIONS: Primary TKA with metal block augmentation and stem extension could effectively restore function in RA patients with advanced forms of knee joint destruction, and be reliable and durable for a mean postoperative period of 6 years. Further study is needed to determine the long-term results of TKA using metal block augmentation and stem extension.

Disc regeneration therapy using marrow mesenchymal cell transplantation: a report of two case studies.

STUDY DESIGN: Marrow mesenchymal cells (MSCs) contain stem cells and possess the ability to regenerate bone, cartilage, and fibrous tissues. Here, we applied this regenerative ability to intervertebral disc regeneration therapy in an attempt to develop a new spinal surgery technique. OBJECTIVE: We analyzed the regenerative restoration ability of autologous MSCs in the markedly degenerated intervertebral discs. SUMMARY OF BACKGROUND DATA: Fusion for lumbar intervertebral disc instability improves lumbago. However, fused intervertebral discs lack the natural and physiologic functions of intervertebral discs. If intervertebral discs can be regenerated and repaired, then damage to adjacent intervertebral discs can be avoided. We verified the regenerative ability of MSCs by animal studies, and for the first time, performed therapeutic intervertebral disc regeneration therapy in patients and obtained favorable findings. METHODS: Subjects were 2 women aged 70 and 67 years; both patients had lumbago, leg pain, and numbness. Myelography and magnetic resonance imaging showed lumbar spinal canal stenosis, and radiograph confirmed the vacuum phenomenon with instability. From the ilium of each patient, marrow fluid was collected, and MSCs were cultured using the medium containing autogenous serum. In surgery, fenestration was performed on the stenosed spinal canal and then pieces of collagen sponge containing autologous MSCs were grafted percutaneously to degenerated intervertebral discs. RESULTS: At 2 years after surgery, radiograph and computed tomography showed improvements in the vacuum phenomenon in both patients. On T2-weighted magnetic resonance imaging, signal intensity of intervertebral discs with cell grafts was high, thus indicating high moisture contents. Roentgenkymography showed that lumbar disc instability improved. Symptom was alleviated in both patients. CONCLUSION: The intervertebral disc regeneration therapy using MSC brought about favorable results in these 2 cases. It seems to be a promising minimally invasive treatment.

Temporal changes in the tensile strength of ultra-high-molecular-weight polyethylene cable embedded in muscle tissue.

BACKGROUND: Wires and cables have been used extensively for spinal sublaminar wiring, but damages to the spinal cord due to compression by metal wires have been reported. We have used more flexible ultra-high-molecular-weight polyethylene cable (Tekmilon tape) instead of metal wires since 1999 and have obtained good clinical outcomes. Although the initial strength of Tekmilon tape is equivalent to metal wires, the temporal changes in the strength of Tekmilon tape in the body should be investigated to show that sufficient strength is maintained over time until bone union is complete. METHODS: Tekmilon tape was embedded into the paravertebral muscle of 10-week-old male Japanese white rabbits. Samples were embedded for 0, 1, 3, 6 or 12 months. At the end of each period, sequential straight tensile strength and sequential knot-pull tensile strength were measured. FINDINGS: The initial strength of Tekmilon tape in muscle tissue was maintained over time, with 92% straight tensile strength and 104% knot-pull tensile strength at 6months, and values of 77% and 100% at 12 months, respectively. Since single knot is clinically relevant, it is very important that the knot-pull tensile strength did not decrease over a 12-month period. This suggests that temporal changes in the tensile strength of Tekmilon tape are negligible at 1 year. INTERPRETATION: Tekmilon tape maintains sufficient strength in vivo until bone union has occurred. It is useful for sublaminar wiring instead of metal materials due to its flexibility and strength and may reduce the risk of neurological damage.

Surgical treatment of congenital kyphosis associated with progressive spastic paralysis in an adult patient.

A 38-year-old man presented with untreated congenital kyphosis associated with progressive spastic gait. To prevent progression of the spastic paralysis, rigid correction of the severe spinal deformity arising from the congenital kyphosis was performed by one-stage posterior closing-wedge osteotomy, without occurrence of neurological complications. Progression of the paralysis has not been identified for 30 months after the operation and a slight improvement in gait was recognized. The current case is categorized as type I deformity of congenital kyphosis in the upper thoracic spine, which is normally treated surgically before the adolescent growth phase begins.

Cervical laminoplasty combined with muscle release in patients with athetoid cerebral palsy.

STUDY DESIGN: A retrospective study comparing cervical laminoplasty with or without muscle release for the treatment of cervical myelopathy resulting from athetoid cerebral palsy. OBJECTIVE: To assess the effectiveness of muscle release in the treatment of athetoid cerebral palsy. SUMMARY OF BACKGROUND DATA: While anterior and/or posterior spinal fusion has been generally accepted as necessary in surgical treatment for cervical myelopathy due to athetoid cerebral palsy, several studies have shown relatively favorable results following laminoplasty. Better results can be obtained by combining muscle release. METHODS.: Study participants were 10 patients who underwent cervical laminoplasty combined with muscle release (mean age, 44.6 years) and 15 patients who underwent cervical laminoplasty alone (mean age, 48.2 years). Therapeutic outcomes 1 year after surgery, as assessed by Kurokawa's methods and JOA scores, were compared between groups. RESULTS: Recovery rate 1 year after surgery was significantly higher for the muscle release group than for the control group. In both groups, recovery rates were significantly better for patients who could walk before surgery. CONCLUSIONS: Cervical laminoplasty combined with muscle release for the treatment of cervical myelopathy due to athetoid cerebral palsy is effective in simplifying postoperative therapy and improving JOA scores.