Surgical management of primary hyperparathyroidixsm

Bilateral neck explorations for primary hyperparathyroidism have a high cure rate (> 95%) and a low rate of morbidity when performed by experienced surgeons. Despite this. there have been many efforts to minimize the procedure in terms of length and region of incision. cost, extent of exploration, and length of hospital stay, while maintaining an excellent outcome. A renewed interest in unilateral neck exploration for primary hyperparathyroidism developed upon the introduction of sestamibi scintigrams as a new preoperative localization technique. The localization of adenomas using this technique was much more accurate than that of previous localization studies. allowing unilateral procedures to become feasible. Several surgeons have advocated a unilateral approach using preoperative sestamibi scanning. Sestamibi-guided parathyroidectomies enable parathyroidectomies to be performed much more rapidly through a significantly less invasive dissection. This procedure results in a very high cure rate with fewer complications, a smaller neck incision, and less use of post-operative narcotics. In patients with hyperparathyroidism. the intraoperative quick PTH assay allows the success of the procedure to be predicted intraoperatively. The intraoperative quick PTH assay is not only helpful in standard initial parathyroidectomies, but also improves the success rate of reoperative procedures. Its use is mandatory in all minimally invasive procedures. Initial reports regarding this innovation have been extremely positive. Nevertheless, some questions have been raised regarding the accuracy and utility of this procedure. Endoscopic parathyroidectomies offer several opportunities for innovation. Various approaches have been shown to be technically feasible, such as endoscopic procedures that rely on CO, insufflation to create a working space or video-assisted procedures in which the working space is maintained through conventional external retraction.

Endoscopic parathyroidectomy

During the last three years, minimally invasive procedures have been adopted for the surgical treatment of primary hyperparathyroidism, because preoperative localization studies such as a high-resolution ultrasonography and sestamibi scintigraphy. guidance by intraoperative scans and the use of a quick, intraoperative PTH assay, have improved. Therefore, endoscopic parathyroidectomy can be performed for patients with primary hyperparathyroidism. The endoscopic procedures range from the 'pure' endoscopic approach characterized by constant gas insufflation and video-assisted gasless techniques. Then, we regard the cosmetic result as important, and adopted the 'pure endoscopic approach because a small incision can be made far from the neck region. We report our technique with no scars in the neck region for endoscopic unilateral neck exploration with primary hyperparathyroidism by an axillary approach and for endoscopic bilateral neck exploration with renal hyperparathyroidism by an anterior chest approach.

Experimental parathyroid transplantation: human parathyroid grafts survived and functioned in mice treated with anti-CD4 monoclonal antibody

Permanent hypoparathyroidism is one of the most difficult of all endocrine disorders to treat medically. To examine the possibility that xenotransplantation can be used to treat hypoparathyroidism, human parathyroid tissues were transplanted into mice. Human parathyroid tissue was taken from specimens excised from patients with hyperparathyroidism. Fresh human parathyroid tissue was implanted under kidney capsule of CBA (H2k) mice. Some mice were treated intraperitoneally with depleting anti-CD4 monoclonal antibody (mAb, YTA 3.1, 100 microg/dose, days -1. 0. 1, 2, 3, and 5). Mice were killed 30 days after transplantation. Survival of parathyroid grafts was examined microscopically and human parathyroid hormone in serum was measured by ELISA. All parathyroid grafts survived under kidney capsule and human parathyroid hormone was strongly detected in serum (621 +/- 576 pg/mL) when recipients were treated with short-course treatment of anti-CD4 mAb. Conversely, no parathyroid tissue was seen microscopically in any recipient mice without anti-CD4 mAb treatment. Human parathyroid hormone was undetectable by ELISA in naive mice and mice transplanted with human parathyroid tissue without short-course treatment of anti-CD4 mAb. Xenogeneic human parathyroid tissue survived and functioned in mice treated with short-course treatment of anti-CD4 mAb.

Familial hyperparathyroidism

Familial hyperparathyroidism (HPT) is a hereditary disease in which HPT is transmitted in an autosomal dominant fashion. It includes a variety of diseases: multiple endocrine neoplasia (MEN) type 1 and type 2, and familial isolated hyperparathyroidism (FIHPT). We screened for MEN 1 mutations by direct nucleotide sequencing of all protein-coding regions and identified the germline mutations of the MEN 1 gene in two families with familial HPT. Patients with FIHPT have multiple abnormal parathyroid glands and are prone to both recurrent and persistent HPT. They frequently present with profound hypercalcemia, in contrast to patients with MEN-associated HPT or sporadic HPT. We recommend subtotal or total parathyroidectomy plus autotransplantation in patients with MEN-associated HPT and patients with FIHPT. Because parathyroid remains or supernumerary glands are often present in the thymus or perithymic tissue, we advocate routine bilateral dissection of the central zone with bilateral cervical thymectomy.

PCNA and Ki-67 as prognostic markers in human parathyroid carcinomas

BACKGROUND

It is widely accepted that histological diagnosis of parathyroid tumors is established with great difficulty. Carcinomas cannot be reliably separated from adenomas by histology alone. In this study, immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and Ki-67 was determined in 10 cases of parathyroid carcinomas, labeling indices (LIs) were calculated, and the results were correlated with the clinical outcomes.

METHODS

Ten cases of formalin-fixed, paraffin-embedded tissue with surgically resected parathyroid carcinoma were used. Immunohistochemical staining for PCNA and Ki-67 was performed and the LIs were calculated. We also examined whether LI could become a useful marker for parathyroid carcinomas.

RESULTS

Although nine patients with minimally invasive growth without recurrence of the tumor showed a low LI for both markers, one patient with a widely invasive neoplasm, and who died, had a high LI.

CONCLUSIONS

These results suggested that the LI of PCNA and Ki-67, in addition to the histological appearance, may be markers of the biological behavior of parathyroid carcinomas. However, this study was on a small scale, so it may be valuable to repeat these studies in a larger group of patients with better defined histological criteria.

Scaphoid nonunion treated by open reduction, anterior inlay bone grafting, and Kirschner-wire fixation

Forty-three patients with ununited fractures of the scaphoid were treated by open reduction, anterior inlay bone grafting and Kirschner wire fixation. All but one achieved bone union. The one failure was successfully treated with a second anterior inlay bone grafting procedure. The average period of cast immobilization was 7 weeks. The presence of an unstable nonunion did not adversely affect the results. In cases with carpal instability, we used a longer corticocancellous graft to restore a more normal alignment of the scaphoid by opening up the volar cortex. Preoperatively, carpal instability was present in 25 patients. In these cases, carpal alignment demonstrated by the radiolunate and scapholunate angle was improved significantly after surgery: the radiolunate angle from 15 degrees before surgery to 2 degrees after surgery, and the scapholunate angle from 67 degrees to 54 degrees, respectively. Pain, restricted motion of the wrist, and the grip strength were improved after surgery.

Secondary acute nonlymphocytic leukemia following successful chemotherapy combining cisplatin, doxorubicin, and cyclophosphamide for stage IV epithelial ovarian cancer

Although chemotherapy is indispensable for the treatment of ovarian cancer, secondary acute leukemia has become increasingly important as one of the most unfavorable late effects according to widespread long-term chemotherapy. We report a patient suffering from acute nonlymphocytic leukemia (ANLL) 3 years after treatment for stage IV ovarian cancer began.

Analysis of the genome of an alkaliphilic Bacillus strain from an industrial point of view

Bacillus species and other microbes with pH optima for growth higher than pH 9 are defined as alkaliphiles. A large number of alkaliphilic Bacillus strains producing useful enzymes, have been isolated from various environments. Some of these enzymes, such as proteases and cellulases from alkaliphilic Bacillus strains, have been commercialized and have brought great advantages to industry and domestic life. To support further development of the enzyme industry, we initiated analysis of the genome of Bacillus halodurans C-125, which is 4.25Mb in size, and constructed a physical and genetic map for comparison with the Bacillus subtilis chromosome. Systematic sequencing of the whole genome of Bacillus halodurans C-125 has been automated since the beginning of May 1998, and sequencing of 98% of the whole genome has been done so far. Through genome analysis, it became apparent that the genome organization of alkaliphilic Bacillus halodurans C-125 is totally different from that of B. subtilis orthologues.

Synthesis of tricyclic compounds as steroid 5alpha-reductase inhibitors

A series of 4-phenoxybutyric acid derivatives attached to a tricyclic skeleton were prepared and evaluated as 5alpha-reductase inhibitors. Structure activity relationships for these compounds in terms of rat epididymis (type 2) 5alpha-reductase inhibitory activities reveal that 1) the substitution pattern at the 11-position of dibenz[b,e]oxepin influenced potency, 2) higher lipophilicity of the tricyclic skeleton improved potency, whereas the existence of a basic nitrogen atom in this skeleton was detrimental to potency, and 3) isobutyl substitution at the 8 positon of the azepine skeleton was tolerated. Among the tricyclic compounds studied, 4-[3-[5-benzyl-8-(2-methyl)propyl-10,11-dihydrodibenz[b,f]azepine- 2-carboxamido]phenoxy]butyric acid (26) was the most potent inhibitor of rat type 2 5alpha-reductase at 0.1 microM.

An automated system for genome analysis to support microbial whole-genome shotgun sequencing

We developed a semi-automated genome analysis system called GAMBLER in order to support the current whole-genome sequencing project focusing on alkaliphilic Bacillus halodurans C-125. GAMBLER was designed to reduce the human intervention required and to reduce the complications in annotating thousands of ORFs in the microbial genome. GAMBLER automates three major routines: analyzing assembly results provided by genome assembler software, assigning ORFs, and homology searching. GAMBLER is equipped with an interface for convenience of annotation. All processes and options are manipulatable through a WWW browser that enables scientists to share their genome analysis results without choosing computer platforms.

Operative treatment of mallet finger due to intra-articular fracture of the distal phalanx

Treatment of a mallet finger due to an intra-articular fracture of the distal phalanx involving one-third or more of the articular surface is controversial. Thirty-three digits with such fractures were treated by open reduction and internal fixation with Kirschner wires. Of these 33 fractures, 13 were associated with subluxation of the distal phalanx. After an average follow-up period of 29 months, the average loss of extension of the distal phalanx was 4 degrees, and the average flexion of the distal interphalangeal joint was 67 degrees. Radiographs of the distal joint in 27 digits appeared normal, while in the remaining 6 digits, slight degenerative changes were noted. In one there was a minor surgical complication. By using the operative technique described, a congruous reduction of the inta-articular fracture and satisfactory function were achieved.

Reidentification of facultatively alkaliphilic Bacillus firmus OF4 as Bacillus pseudofirmus OF4

With a view toward verifying the original classification of alkaliphilic Bacillus firmus OF4, physiological and biochemical characteristics were more extensively catalogued than in original studies, and this catalog was supplemented with 16S rDNA sequence homology and more extensive DNA-DNA hybridization analyses. Phylogenetic analysis of this alkaliphile based on the comparison of multiple 16S rDNA sequences from Bacillus species indicated that this strain is most closely related to Bacillus pseudofirmus. Consistently, in the DNA-DNA hybridization analysis of the alkaliphile and Bacillus reference strains, the highest level of DNA-DNA relatedness (96%) was found between the alkaliphile and the B. pseudofirmus type strain (DSM 8715(T)). The findings support the conclusion that this alkaliphile strain is more closely related to B. pseudofirmus than to B. firmus, and we propose the future use of the designation B. pseudofirmus OF4.

Effects of hydrostatic pressure and temperature on growth and lipid composition of the inner membrane of barotolerant Pseudomonas sp. BT1 isolated from the deep-sea

A barotolerant member of the genus Pseudomonas was isolated from deep-sea sediment obtained from the Japan Trench, at a depth of 4418 m. The growth temperature was found to affect the hydrostatic pressure range in which the bacterium could grow; the optimum hydrostatic pressure for growth shifted to a higher pressure with increasing temperature. We examined the lipid composition of the inner membrane of cells grown at various hydrostatic pressures and temperatures. The fatty acid components of the inner membrane lipids were C16:0, C16:1, C18:0, and C18:1. The phospholipid components of the inner membrane were phosphatidylethanolamine, cardiolipin, phosphatidylglycerol, and phosphatidylserine. It is evident that the effects of elevated hydrostatic pressure are comparable to the effects of low temperature on both the fatty acid composition of the inner membrane lipids and the phospholipid composition of the inner membrane of this bacterium.

Percutaneous myocardial ablation in double-chamber right ventricle

Double-chamber right ventricle (DCRV) exhibits intracavitary outflow obstruction. We report the first case of percutaneous myocardial ablation of DCRV in a 73-year-old patient. An alcohol-induced conus branch occlusion provided the reduction of pressure gradient from 81 to 48 mm Hg and clinical improvement. This strategy may be an alternative therapy to surgery in the adult patients with DCRV. Cathet. Cardiovasc. Intervent. 49:97-101, 2000.

Combined resection of the aorta for an esophageal carcinoma invading the aorta through a right transthoracic approach

The prognosis of esophageal carcinoma invading the thoracic aorta has been extremely poor, as it has been either not resected or only palliatively resected. In recent years a remarkable improvement in survival has been achieved in advanced esophageal carcinoma through an aggressive dissection of the upper mediastinal lymph nodes. This implied that resection only of the aorta without lymph node dissection in these patients was not adequate for curability. Although a resection of the aorta would seem to be performed more easily through a left thoracotomy than through a right thoracotomy, the upper mediastinal lymph node dissection was unsatisfactory through a left thoracotomy. Therefore, we performed combined resection of the aorta using a temporary aorta-aorta bypass together with upper mediastinal lymph node dissection through a right thoracotomy for four patients with the esophageal carcinoma invading the thoracic aorta. This operative procedure was performed safely, and had the advantage that full observation on the extent of the carcinoma was attained together with subsequent radical lymph node dissection in the same field through only the right thoracic approach. This operation may provide a possibility for cure to patients with an esophageal carcinoma invading the aorta, who would otherwise receive only palliative treatment.

Perlecan is essential for cartilage and cephalic development

Perlecan, a large, multi-domain, heparan sulfate proteoglycan originally identified in basement membrane, interacts with extracellular matrix proteins, growth factors and receptors, and influences cellular signalling. Perlecan is present in a variety of basement membranes and in other extracellular matrix structures. We have disrupted the gene encoding perlecan (Hspg2) in mice. Approximately 40% of Hspg2-/- mice died at embryonic day (E) 10.5 with defective cephalic development. The remaining Hspg2-/- mice died just after birth with skeletal dysplasia characterized by micromelia with broad and bowed long bones, narrow thorax and craniofacial abnormalities. Only 6% of Hspg2-/- mice developed both exencephaly and chondrodysplasia. Hspg2-/- cartilage showed severe disorganization of the columnar structures of chondrocytes and defective endochondral ossification. Hspg2-/- cartilage matrix contained reduced and disorganized collagen fibrils and glycosaminoglycans, suggesting that perlecan has an important role in matrix structure. In Hspg2-/- cartilage, proliferation of chondrocytes was reduced and the prehypertrophic zone was diminished. The abnormal phenotypes of the Hspg2-/- skeleton are similar to those of thanatophoric dysplasia (TD) type I, which is caused by activating mutations in FGFR3 (refs 7, 8, 9), and to those of Fgfr3 gain-of-function mice. Our findings suggest that these molecules affect similar signalling pathways.

Reidentification of the keratinase-producing facultatively alkaliphilic Bacillus sp. AH-101 as Bacillus halodurans

Alkaliphilic Bacillus sp. AH-101 was characterized in terms of physiological and biochemical characteristics, and 16S rDNA sequence homology and DNA-DNA hybridization analyses were performed. Phylogenetic analysis of strain AH-101 based on comparison of 16S rDNA sequences revealed that this strain is closely related to Bacillus halodurans. DNA-DNA hybridization of AH-101 and related Bacillus reference strains showed that the highest level of DNA-DNA relatedness (88%) was found between strain AH-101 and the B. halodurans type strain (DSM497). Our findings demonstrate that strain AH-101 is a member of the species B. halodurans.

DNA cytofluorometric analysis using HP/DAPI double staining of parathyroid carcinoma arising in a patient with chronic renal failure and secondary hyperparathyroidism

A 55-year old female patient on long-term hemodialysis began to suffer from pain in her knees and ankles. An ultrasonographic study showed enlargement of all four parathyroid glands. Serum parathyroid hormone and calcium levels were increased. Parathyroidectomy was performed. The right superior gland was enlarged and adherent to surrounding tissues. The other three glands were slightly enlarged. Histologically, the largest gland was a parathyroid carcinoma because capsular and vascular invasion were observed. To our knowledge, there have been only 13 cases of parathyroid carcinomas arising in patients with chronic renal failure reported in the English literature. To evaluate the characteristics of this tumor, we measured nuclear DNA and protein content using stains for HP (hematoporphyrin)/DAPI (4,6-diamidino-2-phenylindole dihydroporphyrin chloride). The nuclear DNA pattern was typically diploid or tetraploid. The cellular protein content was similar to that seen in the controls. The discrepancy between the histology, indicative of malignancy and the cytofluorometrical findings show that it is difficult to determine the prognosis for patients with secondary hyperparathyroidism and parathyroid carcinomas solely from the results of tumor DNA cytometry.

Pre-operative localization and tissue uptake study in parathyroid imaging with technetium-99m-sestamibi

BACKGROUND

The diagnostic ability of 99mTc-sestamibi was compared with other techniques and the mechanism of parathyroid uptake was investigated.

METHODS

Double-phase 99mTc-sestamibi scanning was performed in 52 primary and 28 renal hyperparathyroidism patients. Gene expressions of mdr1 and mrp were examined by reverse transcriptase polymerase chain reaction in parathyroid tissue.

RESULTS

The sensitivity of 99Tc-sestamibi in primary and renal hyperparathyroidism was 91% and 75%, respectively, higher than for ultrasonography, T1/Tc subtraction scintigraphy, or computed tomography. Early 99mTc-sestamibi uptake was washed out in delayed images in 7% and 30% of glands in primary and renal hyperparathyroidism, respectively. Expression of mdr1 and mrp mRNA was found in 5 of 23 and 16 of 31 glands, respectively, and their expression correlated with washout in delayed images.

CONCLUSION

99mTc-sestamibi was the best localization test. mdr1 and mrp were associated with 99Tc-sestamibi washout, but their role in the parathyroid remains unclear.