Asymmetric synthesis of functionalized carbocycles and heterocycles

Anions of 1-halo-4-hexenyl phosphonamides derived from chiral, enantiopure C2 symmetrical 1,2-diamino cyclohexane react at the gamma-position in conjugate addition reactions with alpha, beta-unsaturated carbonyl compounds such as cyclopentenone, 4-(H)-furanone, pyrroline-2-one, and cinnamates to give functionalized adducts. Addition to imines is also possible. The adducts can be transformed into enantiopure or enriched carbocyclic and heterocyclic compounds bearing useable functionality.

Predictors of functional outcomes following limb salvage surgery for lower-extremity soft tissue sarcoma

BACKGROUND AND OBJECTIVES

Patient function has been conceptualized by clinical measures such as joint motion, muscle strength, disability, and general health status. The purpose of the current study was to evaluate tumor and treatment variables predictive of these conceptually different posttreatment functional outcomes in patients treated with limb preservation surgery for lower-extremity soft tissue sarcoma.

METHODS

One hundred seventy-two patients with minimum 1-year follow-up were evaluated using the following outcomes: impairment, measured by the 1987 and 1993 versions of the Musculoskeletal Tumor Society Rating Scale (MSTS); disability, measured by the Toronto Extremity Salvage Score (TESS); and general health status, using the Short Form-36 (SF-36). Tumor and treatment-related variables (age, gender, presenting disease status, anatomic site, tumor size, grade, depth, prior excision, irradiation, bone resection, motor nerve sacrifice, and complications) were extracted from the STS database.

RESULTS

Large tumor size, bone resection, motor nerve resection, and complications were predictive of lower MSTS 1987 and 1993 scores. Patients with large, high-grade tumors who required motor nerve resection were more disabled, as reflected by lower TESS scores. Only age and prior surgery were adverse predictors of SF-36 score.

CONCLUSIONS

These results demonstrate that different factors are predictive of different patient outcomes, specifically, impairment, disability, and general health status. It is important to define function when counseling patients regarding their potential recovery based on tumor and treatment-related variables. J. Surg. Oncol. 2000;73:206-211.

Predictors of functional outcomes following limb salvage surgery for lower-extremity soft tissue sarcoma

BACKGROUND AND OBJECTIVES

Patient function has been conceptualized by clinical measures such as joint motion, muscle strength, disability, and general health status. The purpose of the current study was to evaluate tumor and treatment variables predictive of these conceptually different posttreatment functional outcomes in patients treated with limb preservation surgery for lower-extremity soft tissue sarcoma.

METHODS

One hundred seventy-two patients with minimum 1-year follow-up were evaluated using the following outcomes: impairment, measured by the 1987 and 1993 versions of the Musculoskeletal Tumor Society Rating Scale (MSTS); disability, measured by the Toronto Extremity Salvage Score (TESS); and general health status, using the Short Form-36 (SF-36). Tumor and treatment-related variables (age, gender, presenting disease status, anatomic site, tumor size, grade, depth, prior excision, irradiation, bone resection, motor nerve sacrifice, and complications) were extracted from the STS database.

RESULTS

Large tumor size, bone resection, motor nerve resection, and complications were predictive of lower MSTS 1987 and 1993 scores. Patients with large, high-grade tumors who required motor nerve resection were more disabled, as reflected by lower TESS scores. Only age and prior surgery were adverse predictors of SF-36 score.

CONCLUSIONS

These results demonstrate that different factors are predictive of different patient outcomes, specifically, impairment, disability, and general health status. It is important to define function when counseling patients regarding their potential recovery based on tumor and treatment-related variables. J. Surg. Oncol. 2000;73:206-211.

Periprosthetic bone remodelling around a prosthesis for distal femoral tumours. Measurement by dual-energy X-ray absorptiometry (DEXA)

We used dual-energy x-ray absorptiometry (DEXA) to evaluate the extent of periprosthetic bone remodelling around a prosthesis for distal femoral reconstruction, the Kotz modular femoral tibial replacement (KMFTR; Howmedica, Rutherford, New Jersey). A total of 23 patients was entered into the study which had four parts: 1) 17 patients were scanned three times on both the implant and contralateral legs to determine whether the precision of DEXA measurements was adequate to estimate bone loss surrounding the anchorage piece of the KMFTR; 2) in 23 patients the bone mineral density (BMD) in different regions of interest surrounding the diaphyseal anchorage was compared with that of the contralateral femur at the same location to test whether there was consistent evidence of loss of BMD adjacent to the prosthetic stem; 3) in 12 patients sequential studies were performed about one year apart to compare bone loss; and 4) bone loss was compared in ten patients with implants fixed by three screws and in 13 without screws. The mean coefficients of variation (SD/mean) for the 17 sets of repeated scans ranged from 2.9% to 7.8% at different regions of interest in the KMFTR leg and from 1.4% to 2.5% in the contralateral leg. BMD was decreased in the KMFTR leg relative to the contralateral limb and the percentage of BMD loss in general increased as the region of interest moved distally in the femur. Studies done after one year showed no consistent pattern of progressive bone loss between the two measurements. The ten patients with implants fixed by screws were found to have a mean loss of BMD of 42% in the most distal part of the femur, while the 13 without screw fixation had a mean loss of 11%. DEXA was shown to have adequate precision to evaluate loss of BMD around the KMFTR. This was evident relative to the contralateral leg in all patients and generally increased in the most distal part of the femur. In general, it stabilised between two measurements taken one year apart and was greater surrounding implants fixed by cross-locking screws.

Generation of a novel polysaccharide by inactivation of the aceP gene from the acetan biosynthetic pathway in Acetobacter xylinum

The acetan biosynthetic pathway in Acetobacter xylinum is an ideal model system for engineering novel bacterial polysaccharides. To genetically manipulate this pathway, an Acetobacter strain (CKE5), more susceptible to gene-transfer methodologies, was developed. A new gene, aceP, involved in acetan biosynthesis was identified, sequenced and shown to have homology at the amino acid level with beta-D-glucosyl transferases from a number of different organisms. Disruption of aceP in strain CKE5 confirmed the function assigned above and was used to engineer a novel polysaccharide with a pentasaccharide repeat unit.

Functional outcome in amputation versus limb sparing of patients with lower extremity sarcoma: a matched case-control study

OBJECTIVE

To quantify the differences in physical disability and handicap experienced by patients with lower extremity sarcoma who required amputation for their primary tumor as compared with those treated by limb-sparing surgery.

DESIGN

Matched case-control study. Twelve patients with amputation were matched with 24 patients treated by limb-sparing surgery on the following variables: age, gender, length of follow-up, bone versus soft-tissue tumor, anatomic site, and treatment with adjuvant chemotherapy.

PATIENTS

Patients who underwent above-knee amputation (AKA) or below-knee amputation (BKA) for primary soft-tissue or bone sarcoma, who had not developed local or systemic recurrence, and who had been followed up for at least 1 year since surgery.

MAIN OUTCOME MEASURES

The Toronto Extremity Salvage Score (TESS), a measure of physical disability; the Shortform-36 (SF-36), a generic health status measure; and the Reintegration to Normal Living (RNL), a measure of handicap.

RESULTS

Mean TESS score for the patients with amputations was 74.5 versus 85.1 for the limb-sparing patients. (p = .15). Only the physical function subscale of the SF-36 showed statistically significant differences, with means of 45 and 71.1 for the amputation versus limb-sparing groups, respectively (p = .03). The RNL for the amputation group was 84.4 versus 97 for the limb-sparing group (p = .05). Seven of the 12 patients with amputations experienced ongoing difficulty with the soft tissues overlying their stumps.

CONCLUSIONS

There was a trend toward increased disability for those in the amputation group versus those in the limb-sparing group, with the amputation group showing significantly higher levels of handicap. These data suggest that the differences in disability between amputation and limb-sparing patients are smaller than anticipated. The differences may be more notable in measuring handicap.

Capsular replacement with synthetic mesh: effectiveness in preventing postoperative dislocation after wide resection of proximal femoral tumors and prosthetic reconstruction

We describe a surgical technique for replacing the hip joint capsule using synthetic mesh after oncological resections of the proximal femur that resulted in gross intraoperative instability of the prosthetic reconstruction. The results of its use in 13 patients, 6 of whom also had pelvic resections, are described. These patients were selected from a total group of 88 patients undergoing proximal femoral replacement, 75 of whom did not require capsular replacement (none of these 75 patients have experienced dislocation). In the group requiring capsular reconstruction, 1 of 4 patients with bipolar hemiarthroplasty and 4 of 9 patients with total hip replacements experienced dislocation after operation. Of the dislocated total hip replacements, 1 remains chronically dislocated, and 3 were successfully stabilized by open reduction with further capsular augmentation. Given that the resections involved removal of most of the soft tissues stabilizing the hip joint, we believe that the technique of capsular reconstruction is useful in this difficult group of patients.

A novel fluid resuscitation therapy for hemorrhagic shock

Fluid resuscitation is the usual therapy for hemorrhagic shock, and frequently consists of the infusion of large volumes of electrolyte solutions. However, to be successful, this therapy should be implemented soon after injury. A new treatment method in which the infusion could be delayed might result in a greater survival rate. Reducing the volume of fluid needed is also important. Both of these aspects of fluid resuscitation therapy were addressed in this study by supplementing the electrolyte solution with trans-sodium crocetinate (TSC). Rats were subjected to a severe hemorrhage, with 55% (or greater) of the estimated blood volume being removed over a period of approximately 10 min. There were five animals in each treatment group, and two types of experiments were done. In one, a bolus injection of TSC (or saline control) was given immediately after hemorrhage, followed 30 min later with an infusion of isotonic saline. In the other experiments, reduced infusion volumes of a TSC-saline infusion fluid were used. In both cases, TSC resulted in the survival of the animals while the controls all died. Whole-body oxygen consumption also increased with TSC, reaching 75% of the normal resting value after about 15 min. This correlates well with the increased survival rates seen, since mortality after hemorrhagic shock is associated with decreased oxygen consumption. These results suggest that the use of TSC could allow for later implementation of fluid resuscitation therapy as well as reducing the volume needed.

Bone sarcoma diagnosed at the time of reconstructive hip surgery

OBJECTIVE

To describe the clinical course of a group of patients in whom sarcoma of the proximal femur was diagnosed at the time of reconstructive hip surgery.

DESIGN

A retrospective case series.

SETTING

Final management of all patients took place at a tertiary care centre.

PATIENTS AND INTERVENTIONS

Six consecutive patients with sarcoma of the proximal femur diagnosed at the time of reconstructive hip surgery. The mistaken diagnoses made before surgery were benign tumour (2 patients), avascular necrosis (2 patients), subtrochanteric fracture due to metastasis (1 patient) and granuloma from a loose hip implant (1 patient). The final diagnosis was osteosarcoma in 3 patients and chondrosarcoma in 3. Three patients with high-grade sarcoma received neoadjuvant chemotherapy followed by femoral or pelvic resection, or both, and reconstruction. Two patients with chondrosarcoma underwent wide excision of the tumour with allograft or modular implant reconstruction. One patient with widespread metastasis received only palliative chemotherapy.

MAIN OUTCOME MEASURES

Overall survival with respect to oncologic and functional results of treatment.

RESULTS

Two patients (1 who received only palliative chemotherapy) died after 5 and 21 months' followup, respectively. Average follow-up for the remaining 4 patients was 65.2 months (range from 51 to 75 months). They were disease free at latest follow-up. One patient required amputation for septic complications related to the reconstruction.

CONCLUSIONS

Limb salvage surgery for sarcoma of the proximal femur is challenging when the diagnosis is made at the time of reconstructive surgery rather than through an appropriately planned biopsy. However, this series suggests that limb preservation is feasible and that hindquarter amputation is not the only solution.

Function after subtotal scapulectomy for neoplasm of bone and soft tissue

We describe the functional results in 14 patients (7 men, 7 women) after subtotal scapulectomy for primary bone and soft-tissue tumours at a specialist musculoskeletal oncology unit. Eight had chondrosarcomas, two Ewing's sarcomas, one aggressive fibromatosis and three soft-tissue sarcomas. The mean follow-up was 52 months (6 to 120). Analysis of residual symptoms and of range and strength of movement by physicians used the Musculoskeletal Tumour Society rating scale (MSTS). Physical disability was measured by the patients using the Toronto Extremity Salvage Score (TESS). All 14 patients are still alive, two with systemic disease. Nine had more than 80% of their scapula resected but the glenohumeral joint was preserved in all cases. Eight had full movement and another two achieved 90 degrees of flexion. The mean functional results were good to excellent in all except three patients (mean MSTS = 71.6 and TESS = 79.9). Two of these three patients had considerable pain as a result of brachial neuropathy. Scapulectomy gives an excellent functional result if the glenohumeral joint is preserved. The rotator cuff could be removed without a severe functional deficit provided that the deltoid was reattached to the scapular remnant and the trapezius.

The IL1 receptor accessory protein is responsible for the recruitment of the interleukin-1 receptor associated kinase to the IL1/IL1 receptor I complex

Following interleukin-1 (IL1) stimulation, an IL1 receptor associated kinase (IRAK) is rapidly recruited to the receptor complex. However, it is not understood if IRAK is able to interact directly with the intracellular portion of the IL1-RI or if its recruitment is mediated by a different molecule. Using the yeast two-hybrid system, we have analysed possible protein-protein interactions between IRAK, IL1-RI and IL1-RAcP. We found that IRAK is able to interact with the equivalent cytoplasmic region of the IL1-RAcP but is unable to interact with the cytoplasmic region of the IL1-RI. Immunoprecipitation of the IL1-RAcP followed by Western blot analysis using anti-IRAK antibodies revealed that IRAK co-precipitated with the IL1-RAcP. We propose that, in non-stimulated cells, IRAK is bound to the IL1-RAcP and therefore, following IL1 stimulation, both molecules are recruited simultaneously to the ILI-RI complex.

Cloning of the aceF gene encoding the phosphomannose isomerase and GDP-mannose pyrophosphorylase activities involved in acetan biosynthesis in Acetobacter xylinum

The aceF gene from Acetobacter xylinum was identified and cloned from a genomic DNA library. The complete DNA sequence was determined and computer analysis of the translated gene sequence revealed homology with the deduced amino acid sequence of xanB from Xanthomonas campestris. Therefore aceF is likely to encode a bifunctional enzyme with mannose-6-phosphate isomerase (PMI) and GDP-mannose pyrophosphorylase (GMP) activities. PMI and GMP activities were detected in strains of Escherichia coli expressing the cloned aceF gene.

Primary patellar tumors

Eight cases of primary tumors of the patella were identified in a consecutive series of 587 patients treated surgically for benign or malignant bone tumors. Six cases were benign (5 giant cell tumors and 1 chondroblastoma), and there were 2 malignant tumors (osteosarcoma and malignant fibrous histiocytoma). Both patients with malignant lesions had Rothmund-Thomson syndrome. Benign pulmonary metastases developed in 2 of the patients with giant cell tumor and 1 patient now is deceased 72 months after surgery. Two patients were treated before referral to a tertiary care center; 1 with patellectomy before histologic diagnosis and 1 with curettage. Both resulted in extension of disease into the knee joint. Tumors of the patella require careful assessment before surgical management. Conservation of the bone can be achieved in benign lesions that have adequate residual bone remaining at the articular surface. Conservation of the extremity is possible in malignant tumors, but reconstruction of the extensor mechanism is difficult.

The cpsABCDE genes involved in polysaccharide production in Streptococcus salivarius ssp. thermophilus strain NCBF 2393

A 4074-bp EcoRI fragment of Streptococcus salivarius ssp. thermophilus (S. thermophilus) chromosomal DNA containing genes involved in exocellular polysaccharide (EPS) was identified and cloned. The nucleotide sequence of this fragment was determined and found to contain one partial and four complete open reading frames. These were designated cpsA, cpsB, cpsC, cpsD and cpsE and encoded proteins of > 130, 243, 230, 246 and 455 amino acids, respectively, that showed homology with the genes of the cps cluster, involved in polysaccharide biosynthesis, in Streptococcus pneumoniae Type 19F. The cpsA gene is predicted to encode a transcriptional regulator, while cpsC and cpsD are predicted to encode proteins involved in polysaccharide polymerization and export. The cpsE gene is likely to encode the phosphate-prenyl glycosyl-1-phosphate transferase catalyzing the first step in polysaccharide biosynthesis in S. thermophilus. Southern blot analysis revealed that cpsE is found only in polysaccharide producing strains of S. thermophilus.

When the diagnosis is cancer: patient communication experiences and preferences

BACKGROUND

Discrepancies exist between reported experiences of patients when they have been given a diagnosis of cancer, published guidelines for telling a diagnosis, and patterns of communication patients rate as favorable. Several studies have identified what happened and what is important to cancer patients when told their diagnosis, but no studies have addressed subsequent communications concerning the implications of the diagnosis and treatment choices. This study extended previous research by investigating the experiences and preferences for communication about diagnosis, prognosis, and treatment of patients diagnosed with breast cancer or melanoma.

METHODS

A self-report questionnaire was designed for this study based on previous research and qualitative data generated from focus groups. Patients with breast cancer or melanoma answered questions about their experiences with communication at the time of diagnosis and concerning prognosis, treatment and related issues. Comparisons were made between patient experiences, preferences and published guidelines. Differences between the experiences of breast cancer and melanoma patients were tested and the relationship between communication and subsequent psychological adjustment to cancer was assessed.

RESULTS

Patient preferences for communication during diagnostic consultation were not always consistent with published guidelines. Type of cancer did not significantly affect patient preferences. Psychological adjustment was related to patient ratings of the quality of doctor discussion about treatment options, but not about the diagnosis of cancer and its implications. Patients who wanted more emotional support at the time of diagnosis subsequently experienced poorer psychological adjustment.

CONCLUSIONS

The differences in patient preferences show that a list of prescriptions for how to disclose a cancer diagnosis is too simplistic. Guidelines for clinicians should be derived from patient-based data rather than be limited only to clinical opinion. Guidelines concerning communication at the time of diagnosis also need to address discussions concerning the implications of the diagnosis and making treatment decisions.

Identification, cloning and sequencing the aceA gene involved in acetan biosynthesis in Acetobacter xylinum

The aceA gene from Acetobacter xylinum was identified and cloned from a genomic DNA library. The complete DNA sequence was determined and computer analysis of the translated gene sequence revealed homology with the deduced amino acid sequence of gumD from Xanthomonas campestris. Therefore aceA is likely to encode the phosphate-prenyl glucose l-phosphate transferase catalyzing the first step in acetan biosynthesis in A. xylinum.

On the receiving end. V: Patient perceptions of the side effects of cancer chemotherapy in 1993

BACKGROUND

A study conducted in 1983 to identify and rank the symptoms experienced by patients receiving cancer chemotherapy reported that vomiting and nausea were the most important symptoms experienced. With the advent of new antiemetic regimens and changes in cancer chemotherapy, it was anticipated that changes may have occurred in patient perception of symptoms. The study was therefore repeated in 1993.

PATIENTS AND METHODS

One hundred and fifty-five cancer patients receiving chemotherapy at a large urban teaching hospital participated in the study. Patients selected from cards listing symptoms all those experienced and the five most troublesome.

RESULTS

Patients reported experiencing an average of 20 symptoms (13 physical and 7 psychosocial). Nausea was reported as the most severe symptom followed by tiredness and loss of hair. Vomiting which was the most severe symptom in 1983, now ranked 5th. Differences were detected in the symptoms experienced and reported as most severe, between chemotherapy regimens, between older and younger patients and between males and females.

CONCLUSIONS

The results suggest a reduction in the severity of some symptoms experienced while receiving chemotherapy and a shift from concerns about physical to psychosocial issues.

Genetic analysis of the acetan biosynthetic pathway in Acetobacter xylinum: nucleotide sequence analysis of the aceB, aceC, aceD and aceE genes

Sequence analysis of a 5.323 kb chromosomal DNA fragment from Acetobacter xylinum involved in the biosynthesis of the exopolysaccharide acetan, revealed the presence of four ace genes designated aceB, aceC, aceD and aceE. Comparison of translated gene sequences to the databanks was used to assign putative gene functions. AceB displayed strong homology to a glucose-diphosphoprenyl beta, D-glucose transferase from Xanthomonas campestris, while AceC was homologous to a cellobiosyl-diphosphoprenyl alpha, D-mannose transferase from the same organism. Thus these genes encode enzymes catalyzing the second and third steps of the acetan biosynthetic pathway. AceD and AceE were homologous to ExoP and ExoT respectively from Rhizobium meliloti and are likely to be involved in acetan polymerization and export.

Giant cell tumor of the proximal fibula: surgical management

Five patients with giant cell tumor of the proximal fibula were treated with intralesional excision of the lesion, preservation of the peroneal nerve, and reconstruction of the lateral collateral ligament. At minimum 24-month follow-up there have been no local recurrences. Four patients exhibit normal function of the peroneal nerve and one has grade 4 strength of the muscles innervated by this nerve. No patient demonstrated varus instability. Marginal excision with nerve preservation and reconstruction of the ligament is a worthwhile procedure for treatment of this relatively uncommon lesion.

The effect of intramedullary cement on intercalary allograft reconstruction of bone defects after tumour resection: a pilot study

OBJECTIVE

A pilot study to evaluate the surgical and functional results of resection and reconstruction of diaphyseal bone tumours with cemented and uncemented intercalary allografts.

DESIGN

A retrospective case series.

SETTING

A quaternary care unit within a teaching hospital.

PATIENTS

Twenty-two patients with diaphyseal bone tumours treated between 1988 and 1992, with mean follow-up of 38 months (range from 20 to 70 months).

INTERVENTIONS

Diagnostic biopsy in all patients. Preoperative and postoperative chemotherapy in patients with high-grade sarcoma. En-bloc excision of all tumours. Reconstruction of the defect with cemented (15 patients) or uncemented (7 patients) intercalary allografts.

MAIN OUTCOME MEASURES

Nonunion at one or both osteosynthesis sites, death from systemic disease, amputation.

RESULTS

Six of the 22 patients died of systemic disease with the graft intact, and 3 subsequently had amputation for either local recurrence (2 patients) or failure of free tissue transfer (1 patient), leaving 13 patients alive with the allograft in situ at an average of 36 months (range from 24 to 64 months). There were no revision procedures to remove or replace the original allograft. Five patients had nonunion at one or more osteosynthesis sites on plain radiographs 9 months after resection. Four patients with nonunion were in the cemented group of 13 patients available for assessment at 9 months, and 1 was in the uncemented group of 5 patients available for assessment at 9 months. There were two graft fractures, both in the uncemented group.

CONCLUSION

The results of this pilot study offer guarded support for the use of pressurized cement in allografts prior to reconstruction of intercalary defects.

Genetic analysis of the acetan biosynthetic pathway in Acetobacter xylinum

We have identified, cloned and sequenced an 8422 base pair fragment of Acetobacter xylinum genomic DNA containing part of the acetan biosynthetic gene cluster. Computer analysis of the nucleotide sequence data generated revealed the presence of six open reading frames. Comparison of the translated sequences of putative genes to the amino acid sequences of genes from other organisms was used to assign functions to the aceA, aceC and manB genes. These genes were predicted to encode a UDP-glycosyl transferase, a GDP-mannosyl transferase and a phosphomannose isomerase/GDP-mannose pyrophosphorylase, respectively.