A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field

A new multi-line cusp magnetic field plasma device consisting of electromagnets with core material has been constructed with a capability to experimentally control the relative volume fractions of magnetized to unmagnetized plasma volume as well as accurate control on the gradient length scales of mean density and temperature profiles. Argon plasma has been produced using a hot tungsten cathode over a wide range of pressures 5 × 10^-5 -1 × 10^-3 mbar, achieving plasma densities ranging from 10⁹ to 10¹¹ cm^-3 and the electron temperature in the range 1-8 eV. The radial profiles of plasma parameters measured along the non-cusp region (in between two consecutive magnets) show a finite region with uniform and quiescent plasma, where the magnetic field is very low such that the ions are unmagnetized. Beyond that region, both plasma species are magnetized and the profiles show gradients both in temperature and density. The electrostatic fluctuation measured using a Langmuir probe radially along the non-cusp region shows less than 1% (δI_isat/I_isat < 1%). The plasma thus produced will be used to study new and hitherto unexplored physics parameter space relevant to both laboratory multi-scale plasmas and astrophysical plasmas.

Pioneering technique using Acellular Dermal Matrix in the rescue of a radiation ulcer

BACKGROUND

Radiotherapy as an adjuvant to mastectomy is integral to the treatment of breast cancer, but can result in skin ulceration. Skin ulceration following radiotherapy is traditionally managed by removing the implant and allowing the skin to heal by secondary intention.

CASE REPORT

A 42-year-old woman underwent radiotherapy following a breast reconstruction. She developed a 2 x 3cm radiation ulcer. The ulcer was managed by removing the implant and performing capsulectomy. A Beckers 50 expander was placed and reinforced with acellular dermal matrix inferolaterally. At follow-up the patient had a good cosmetic outcome.

CONCLUSION

Post-radiation skin ulcers present a challenge to treat with no current standardised management. The use of acellular dermal matrix may present a new technique to promote healing in these testing cases.

Temperature-dependent ideal strength and stacking fault energy of fcc Ni: a first-principles study of shear deformation

Variations of energy, stress, and magnetic moment of fcc Ni as a response to shear deformation and the associated ideal shear strength (τ(IS)), intrinsic (γ(SF)) and unstable (γ(US)) stacking fault energies have been studied in terms of first-principles calculations under both the alias and affine shear regimes within the {111} slip plane along the <112> and <110> directions. It is found that (i) the intrinsic stacking fault energy γ(SF) is nearly independent of the shear deformation regimes used, albeit a slightly smaller value is predicted by pure shear (with relaxation) compared to the one from simple shear (without relaxation); (ii) the minimum ideal shear strength τ(IS) is obtained by pure alias shear of {111}<112>; and (iii) the dissociation of the 1/2[110] dislocation into two partial Shockley dislocations (1/6[211] + 1/6[121]) is observed under pure alias shear of {111}<110>. Based on the quasiharmonic approach from first-principles phonon calculations, the predicted γ(SF) has been extended to finite temperatures. In particular, using a proposed quasistatic approach on the basis of the predicted volume versus temperature relation, the temperature dependence of τ(IS) is also obtained. Both the γ(SF) and the τ(IS) of fcc Ni decrease with increasing temperature. The computed ideal shear strengths as well as the intrinsic and unstable stacking fault energies are in favorable accord with experiments and other predictions in the literature.

Skin puckering as a sign of humeral neck fracture

To the best of our knowledge, this is the first clinical report of skin puckering associated with fractured neck of humerus. Its significance may vary in different locations and its presence should be added to other physical and radiological signs to aid decision making.

Continuous compartment pressure monitoring vs. clinical monitoring in tibial diaphyseal fractures

A cohort of 109 consecutive patients with a tibial fracture who underwent continuous compartment pressure monitoring of the anterior compartment of the leg were reviewed and compared to a historical control group of the immediate previous 109 patients who were clinically monitored. Of these patients 33 underwent fasciotomies for acute compartment syndrome in association with tibial diaphyseal fractures. Seventeen patients had continuous compartment pressure monitoring and 16 clinical assessments alone. The fasciotomy rate of patients who underwent continuous compartment pressure monitoring was 15.6%. Patients who were not monitored had a fasciotomy rate of 14.7%. The mean time delay from injury to fasciotomy was 22 h in the monitored group and 23 h in the non-monitored group. Continuous compartment pressure monitoring did not increase the rate of unnecessary fasciotomies. We could not demonstrate a significant difference in terms of clinical outcome and time delay from injury to fasciotomy.

Relationship of body mass index to early complications in knee replacement surgery

BACKGROUND

The purpose of this study was to evaluate the relationship between body mass index and early complications following knee replacement.

METHODS

Five hundred and twenty-seven patients who underwent primary knee replacement were recruited. All these patients were subjected to a pre-operative assessment and follow-up at 6 weeks and 1 year following surgery. Any complication occurring during this period was recorded. Complications were grouped into systemic and local, minor and major.

RESULTS

12.1% (N = 64) patients had an early complication following knee replacement surgery; 9.2% (N = 48) patients had a major complication. Overall BMI did not seem to influence significantly the rate of complication with a P-value of 0.338. A stronger correlation was found between the surgeon and presence of complication with a P-value of 0.004.

CONCLUSIONS

BMI has a weak correlation to early complications following joint replacement surgery. The operating surgeon seems to have a stronger correlation to early complications as compared with BMI.

Outcome of traumatic subtrochanteric femoral fractures fixed using cephalo-medullary nails

We performed a retrospective review of 101 patients sustaining 102 traumatic, non-pathological subtrochanteric fractures treated with cephalo-medullary nailing over a period of 6 years from 1999 to 2005. Mean follow up was 24 weeks (range: 6-96). Twenty patients were lost to follow up and 21 died, whilst 57 of 60 fractures were followed to union. There were 19 fractures fixed in varus, as defined as a varus angulation of greater than 10 degrees at the fracture site. Implant failure, 9 of the 10 malunions and all 3 of the non-unions occurred in the varus group whilst only 1 malunion occurred in the satisfactory reduction group. This difference in outcome is statistically significant (p<0.0001). Twenty four of the 60 patients had undergone open reduction at the time of fixation. There were three malunions and one non-union in the open reduction group compared with six and two, respectively in the closed group (p>0.05). Post-operative recovery rates, infection rates and other complications were similar for both groups. We therefore advocate the use of open reduction where necessary to avoid varus malreduction to avoid such complications, particularly as open reduction was not associated with a higher complication rate in this series. The study supports the use of cephalo-medullary nailing for subtrochanteric fractures with a union rate of 95%.

Prosodic discrimination in patients with schizophrenia

Fifteen patients with prominent positive symptoms of schizophrenia and 15 normal controls performed verbal prosodic and pure musical discrimination tasks, with changes in pitch and timing parameters. The patients' performance was comparable to that of controls on the discrimination of terminal pitch changes, but significantly poorer on the more difficult internal pitch discrimination. The latter deficit was positively correlated with the severity of their positive symptoms. The results suggest that patients have a deficit in processing fundamental aspects of prosody, which is associated with the presence of positive symptoms.

Bone morphogenetic proteins in orthopaedic trauma: recent clinical findings with human bone morphogenetic protein-2 (rhBMP-2)

This article introduces papers based on presentations from a symposium entitled "Bone Morphogenic Protein Advisory Meeting in Orthopaedic Trauma", where recent clinical findings with human bone morphogenetic protein-2 (rhBMP-2) were reviewed. It also presents two case studies which illustrate the clinical problems with the potential morbidity of tibial fractures and the potential benefits of the use of rhBMP-2 at surgery. The article concludes with a summary of the symposium. Tibial shaft fracture repair is associated with a significant financial burden on the patient, the health care providers and the medical insurance companies. It is anticipated that the clinical advantages of rhBMP-2 could lead to cost savings both inside and outside the hospital setting.

Ghrelin stimulates insulin-induced glucose uptake in adipocytes

The gastric and hypothalamic hormone ghrelin is the endogenous agonist of the growth hormone secretagogue receptor GHS-R1(a). Ghrelin stimulates growth hormone release and appetite via the hypothalamus. However, putative direct peripheral effects of ghrelin remain poorly understood. Rat adipose tissue expresses GHS-R1(a) mRNA, suggesting ghrelin may directly influence adipocyte function. We have investigated the effects of ghrelin on insulin-stimulated glucose uptake in isolated white adipocytes in vitro. RT-PCR confirmed the expression of GHS-R1(a) mRNA in epididymal adipose tissue. However, GHS-R1(a) expression was not detected in the peri-renal fat pads. Ghrelin increased insulin-stimulated deoxyglucose uptake in isolated white adipocytes extracted from the epididymal fat pads of male Wistar rats. Ghrelin 1000 nM significantly increased deoxyglucose uptake by 55% in the presence of 0.1 nM insulin. However, ghrelin administration in the absence of insulin had no effect on adipocyte deoxyglucose uptake, suggesting that ghrelin acts synergistically with insulin. Des-acyl ghrelin, a major circulating non-octanylated form of ghrelin, had no effect on insulin-stimulated glucose uptake. Furthermore, acylated ghrelin had no effect on deoxyglucose uptake in adipocytes from peri-renal fat pads suggesting that ghrelin may influence glucose uptake via the GHS-R1(a). Ghrelin therefore appears to directly potentiate adipocyte insulin-stimulated glucose uptake in selective adipocyte populations. Ghrelin may play a role in adipocyte regulation of glucose homeostasis.

A new approach for plate fixation of midshaft clavicular fractures

The majority of midshaft clavicle fractures unite uneventfully. Although the indications for operative intervention are limited and reported complication rates high, there are circumstances in which surgery is required. We describe a new, infraclavicular surgical approach to the clavicle used in a series of 89 patients over 9 years. Average time to union was 13.5 weeks. There was one case of deep infection and one of non-union, both of which resolved with further treatment. These results compare very favourably with previously published series and we submit that this operative approach allows safe management of an otherwise potentially hazardous procedure.

Human pitch perception is reflected in the timing of stimulus-related cortical activity

'Pitch' refers to a sound's subjective highness or lowness, as distinct from 'frequency,' which refers to a sound's physical structure. In speech, music and other natural contexts, complex tones are often perceived with a single pitch. Using whole-head magnetoencephalography (MEG) and stimuli that dissociate pitch from frequency, we studied cortical dynamics in normal individuals who extracted different pitches from the same tone complexes. Whereas all subjects showed similar spatial distributions in the magnitude of their brain responses to the stimuli, subjects who heard different pitches exhibited contrasting temporal patterns of brain activity in their right but not their left hemispheres. These data demonstrate a specific relationship between pitch perception and the timing (phase) of dynamic patterns of cortical activity.

Low-level determination of polymorph composition in physical mixtures by near-infrared reflectance spectroscopy

Near-infrared reflectance spectroscopy (NIRS) was employed to quantify sulfathiazole (STZ) forms I and III in binary physical mixtures in which one form was the dominant component. Physical mixtures of the polymorph pair were made by weight, ranging from 0 to 5% STZ form I mixed with STZ form III, and near-infrared spectra of the powder samples contained in glass vials were obtained over the wavelength region of 1100 to 2500 nm. A calibration plot was constructed by plotting STZ form I weight percent against a ratio of second-derivative values of log (1/R') (where R' is the relative reflectance) versus wavelength. The coefficients of determination, R(2), were > 0.9983 and standard errors were low for these calibration models. The instrument reproducibility, method error, and limits of detection (LOD) and quantification (LOQ) of the method were assessed. The LOD and LOQ were determined from the standard deviation of the response of the 0% analyte sample (0% STZ form I containing 100% STZ form III). The LOQ was subsequently validated with independently prepared samples. The results show that polymorphs can be quantified in binary physical mixtures in the 0.3% polymorph composition range. These studies indicate that NIRS is a precise and accurate quantitative tool for determination of polymorphs in the solid state, is comparable to other characterization techniques, and is more convenient to use than many other methods.

Thyroglobulin messenger ribonucleic acid levels in the peripheral blood of children with benign and malignant thyroid disease

Reverse transcriptase-PCR has identified thyroglobulin mRNA (Tg mRNA) in peripheral blood of normal adults and adults with thyroid cancer. However, no children were studied. The primary objective of this study was to determine whether whole blood Tg mRNA levels differ between benign and malignant thyroid disease in children. The secondary goals were to determine whether whole blood Tg mRNA levels vary with age or pubertal development among children with thyroid disease. Whole blood Tg mRNA levels were determined in 38 children (29 girls, nine boys; median age, 14.5 y; range, 4.8-20.4 y) with benign and malignant thyroid disease and correlated with diagnosis, age, pubertal status, thyroid size, and serum levels of free thyroxine, TSH, and Tg protein. Tg mRNA levels ranged from 3.3 to 104 pg Eq/microg total thyroid RNA (mean, 28 +/- 20.2 pg Eq/microg total thyroid RNA) and were similar in benign and malignant disorders (p = 0.67). However, in children with previously treated papillary thyroid cancer, Tg mRNA levels directly correlated with total body (131)I uptake (p = 0.026) and serum Tg protein (p = 0.037). There was no difference between boys and girls, and no change with pubertal maturation. In children with benign thyroid disease, Tg mRNA levels correlated with serum TSH (p = 0.031), but not with diagnosis, age, Tanner stage, or thyroid size. We conclude that Tg mRNA levels are similar in children with benign and malignant thyroid disease and unchanged by age or pubertal status, but correlated with tumor burden in previously treated papillary thyroid cancer.

Calcaneal compartment syndrome after tibial fractures

Compartment syndrome of the newly discovered calcaneal compartment of the foot is a theoretical possibility following tibial fracture due to the communication with the deep posterior compartment of the calf. Forty-nine patients were reviewed at least 18 months after open or closed tibial shaft fractures treated with tibial nailing in order to determine the prevalence of foot deformities secondary to previously undetected calcaneal or leg compartment syndromes. Ankle movements, foot height, length of feet and degree of clawing of the toes were all measured and compared with the unaffected opposite side. None of the patients complained of any symptoms from their feet and none had any significant foot deformities. Calcaneal compartment syndrome is rare after tibial fracture and routine measurement of calcaneal compartment pressures after such injuries is not indicated.

Quantitative analysis of polymorphs in binary and multi-component powder mixtures by near-infrared reflectance spectroscopy

Near-infrared reflectance spectroscopy was employed to quantify polymorphs in binary and multi-component powder mixtures. Sulfamethoxazole (SMZ) forms I and II were used as model polymorphs for this study. The instrument reproducibility, method error, precision, and limits of detection and quantification of the method were assessed. Physical mixtures of the polymorph pair were made by weight, ranging from 0 to 100% SMZ form I in II. Near-infrared spectra of the powder samples contained in glass vials were obtained over the wavelength region of 1100-2500 nm. A calibration plot was constructed by plotting SMZ form I weight percent against a ratio of second derivative values of log(1/R') (where R' is the relative reflectance) versus wavelength. The coefficients of determination, R(2), were generally greater than 0.9997 and standard errors were low for all the systems. Instrument error was assessed by analyzing a sample 10 times without perturbation. Method error was assessed in the same manner except the sample was re-mixed between analyses. A precision study was conducted by analyzing aliquots from a larger homogeneous sample. Limits of detection (LOD) and quantification (LOQ) were determined from the standard deviation of the response of the blank samples (100% SMZ form II, undiluted or diluted with 60% lactose). These limits were subsequently validated with independent samples. The results show that polymorphs can be quantified in binary and multi-component mixtures in the 2% polymorph composition range. These studies indicate that NIRS is a precise and accurate quantitative tool for determination of polymorphs in the solid-state, is comparable to other characterization techniques, and is more convenient to use than many other methods.

Temporal patterns of human cortical activity reflect tone sequence structure

Despite growing interest in temporal aspects of auditory neural processing, little is known about large-scale timing patterns of brain activity during the perception of auditory sequences. This is partly because it has not been possible to distinguish stimulus-related activity from other, endogenous brain signals recorded by electrical or magnetic sensors. Here we use amplitude modulation of unfamiliar, approximately 1-minute-long tone sequences to label stimulus-related magnetoencephalographic neural activity in human subjects. We show that temporal patterns of activity recorded over particular brain regions track the pitch contour of tone sequences, with the accuracy of tracking increasing as tone sequences become more predictable in structure. In contrast, temporal synchronization between recording locations, particularly between sites over the left posterior hemisphere and the rest of the brain, is greatest when sequences have melody-like statistical properties, which may reflect the perceptual integration of local and global pitch patterns in melody-like sequences. This method is particularly well suited to studying temporal neural correlates of complex auditory sequences (such as speech or music) which engage multiple brain areas as perception unfolds in time.

Routine radiography following ankle fracture fixation: a case for limiting its use

The use of fluoroscopic screening in the orthopaedic theatre is a necessary operative aid in many procedures. Modern systems give good image resolution and allow the production of per-operative hard-copy prints. This study was performed to compare these prints with postoperative radiographs in 41 patients who underwent internal fixation for an ankle fracture in a 6-month period. The hard-copy prints and the postoperative X-ray films were independently assessed for several features, which included status of the tibiofibular syndesmosis, fibular length, talo-crural angle, talar tilt, presence and size of a posterior malleolar fracture, and abnormality of the medial clear space. Information was also recorded as to whether there had been a change in postoperative management plan after review of the check X-ray. Of the 41 cases, 30 were suitable for full assessment. In 25 of these cases there was no difference in the information provided by the hard-copy prints from fluoroscopic images and the postoperative check X-rays. In the other five cases, the differences were not significant. In none of the cases did the check X-ray effect a change in postoperative management. We therefore suggest that if per-operative hard-copy prints are obtained from the fluoroscopic images, postoperative radiographs of the ankle are only necessary in exceptional circumstances.

Quantitative reverse transcription-PCR measurement of thyroglobulin mRNA in peripheral blood of healthy subjects

BACKGROUND

Thyroglobulin mRNA can be detected qualitatively in the peripheral blood of patients with metastatic thyroid cancer, thyroid cancer patients with residual thyroid bed uptake, and individuals with no known thyroid disease with intact thyroid glands by use of a lengthy, highly sensitive extraction technique. To improve and broaden the clinical usefulness of this assay, we developed a quantitative reverse transcription (RT)-PCR assay for thyroglobulin mRNA, using RNA recovered from whole blood with a simplified extraction technique.

METHODS

Whole blood was drawn from 32 healthy subjects in standard EDTA blood collection tubes. Total RNA was extracted from whole blood, using the PUREscript RNA Isolation Kit. RT-PCR using intron-spanning primers was used to quantitatively amplify thyroglobulin mRNA, using the ABI PRISM 7700 Sequence Detection System with a fluorescent-labeled, thyroglobulin-specific oligonucleotide probe. Thyroid RNA calibration curves were created using total RNA recovered from a single nondiseased thyroid gland.

RESULTS

Qualitative RT-PCR demonstrated the presence of thyroglobulin mRNA in the whole blood sample of each healthy subject. The mean concentration of thyroglobulin mRNA detected in these subjects was 433 +/- 69 ng of total thyroid RNA per liter of whole blood (range, 26-1502 ng/L). Overall assay imprecision (CV) was 24% for five samples analyzed 10 times each in separate analytical runs on different days.

CONCLUSIONS

Thyroglobulin mRNA can be accurately detected and quantified in peripheral blood from healthy subjects. This new quantitative technique may improve the clinical utility of circulating thyroglobulin mRNA detection in patients with thyroid disease.

Processing syntactic relations in language and music: an event-related potential study

In order to test the language-specificity of a known neural correlate of syntactic processing [the P600 event-related brain potential (ERP) component], this study directly compared ERPs elicited by syntactic incongruities in language and music. Using principles of phrase structure for language and principles of harmony and key-relatedness for music, sequences were constructed in which an element was either congruous, moderately incongruous, or highly incongruous with the preceding structural context. A within-subjects design using 15 musically educated adults revealed that linguistic and musical structural incongruities elicited positivities that were statistically indistinguishable in a specified latency range. In contrast, a music-specific ERP component was observed that showed antero-temporal right-hemisphere lateralization. The results argue against the language-specificity of the P600 and suggest that language and music can be studied in parallel to address questions of neural specificity in cognitive processing.

Processing prosodic and musical patterns: a neuropsychological investigation

To explore the relationship between the processing of melodic and rhythmic patterns in speech and music, we tested the prosodic and musical discrimination abilities of two "amusic" subjects who suffered from music perception deficits secondary to bilateral brain damage. Prosodic discrimination was assessed with sentence pairs where members of a pair differed by intonation or rhythm, and musical discrimination was tested using musical-phrase pairs derived from the prosody of the sentence pairs. This novel technique was chosen to make task demands as comparable as possible across domains. One amusic subject showed good performance on both linguistic and musical discrimination tasks, while the other had difficulty with both tasks. In both subjects, level of performance was statistically similar across domains, suggesting shared neural resource for prosody and music. Further tests suggested that prosody and music may overlap in the processes used to maintain auditory patterns in working memory.

Ongoing immunologic activity after short courses of pulse cyclophosphamide in the NZB/W murine model of systemic lupus erythematosus

OBJECTIVE

Short courses of intermittent pulse cyclophosphamide (CY) have mitigated ovarian toxicity but have also led to incomplete or unsustained remissions of active systemic lupus erythematosus (SLE) in many patients, prompting an evaluation of the immunologic effects of this regimen in the NZB/W female mouse (B/W) model of human SLE.

METHODS

Phenotypic and functional characteristics of spleen lymphocytes from B/W mice treated with short courses of intraperitoneal (i.p.) CY were compared to those from untreated control B/W mice.

RESULTS

After a single dose (250 mg/kg) of i.p. CY, spleen lymphocyte subpopulations fell abruptly but recovered within 4 weeks. Four monthly doses of i.p. CY (starting at 5 months of age) led to a sustained reduction in spleen lymphocyte subpopulations and a parallel decrease in the number of spleen cells spontaneously secreting immunoglobulin and anti-DNA antibody to about 30% of the number seen in untreated control B/W mice. Lipopolysaccharide induced secretion of total IgG and IgG anti-DNA by cultured spleen cells was not diminished one month after the 4 month course of i.p. CY.

CONCLUSION

The 4 month course of i.p. CY produced a marked reduction in the number of activated B cells producing autoantibody, but did not achieve sustained immunomodulation judged by the unaltered proportion of spleen B cells spontaneously secreting immunoglobulin and anti-DNA, as well as the response to polyclonal activators of B cells. These results suggest a continued susceptibility to flares of SLE activity after brief courses of intensive immunosuppressive therapy.

Differential requirement of protein tyrosine kinase and protein kinase C in the generation of IL-2-induced LAK cell and alpha CD3-induced CD3-AK cell responses

This study examined the role of protein tyrosine kinase (PTK) and protein kinase C (PKC) in the signal transduction pathways for lymphocyte activation through IL-2R to generate LAK cells and through TCR-CD3 to generate CD3-AK cells. Two PTK inhibitors [herbimycin A and genistein (PTK-I)] and two PKC inhibitors [calphositin C and staurosporine (PKC-I)] were used in the experiments. It was found that the primary activation pathway through IL-2R was PTK-dependent; that is, generation of both the IL-2-induced proliferative and the cytotoxic responses was completely abrogated by PTK-I and not by PKC-I. Quite different results were obtained with the alpha CD3-induced CD3-AK cell response. First, the alpha CD3-induced proliferation was only partially inhibited by PTK-I or PKC-I alone. Second, generation of CD3-AK cytotoxic response was primarily PKC-dependent; that is, only PKC-I induced significant inhibition. Genistein was found to reduce protein tyrosine phosphorylation in both LAK cells and CD3-AK cells, indicating that CD3-AK cells were also susceptible to PTK-I treatment. Further studies showed that PTK-I and not PKC-I suppressed perforin mRNA expression and N-2-benzyoxycarbonyl-L-lysine thiobeneylester esterase production in LAK cells, and the opposite was true for CD3-AK cells. These results indicate that different pathways were employed in lymphocyte activation through IL-2R and TCR-CD3. The former pathway is primarily PTK-dependent. Activation through TCR-CD3 is a more complex event.(ABSTRACT TRUNCATED AT 250 WORDS)

External fixator pin placement in the forearm: how safe is it? An anatomical study

An anatomical study was undertaken using cadaveric forearms to identify the best technique and angle of pin placement for external fixator pins. We have found that inserting pins through stab incisions risks transfixion of the underlying structures and leads to an increased morbidity. We conclude that inserting pins under direct vision is much safer and that the optimum angle of pin insertion is in the coronal plane, parallel to the plane of the metacarpals.

Fixation of intertrochanteric fractures of the femur. A randomised prospective comparison of the gamma nail and the dynamic hip screw

We have prospectively compared the fixation of 100 intertrochanteric fractures of the proximal femur in elderly patients with random use of either a Dynamic Hip Screw (DHS) or a new intramedullary device, the Gamma nail. We found no difference in operating time, blood loss, wound complications, stay in hospital, place of eventual discharge, or the patients' mobility at final review. There was no difference in failure of proximal fixation: cut-out occurred in three cases with the DHS, and twice with the Gamma nail. However, in four cases fracture of the femur occurred close to the Gamma nail, requiring further major surgery. In the absence of these complications, union was seen by six months in both groups.

Interactions between murine B lymphocyte surface membrane molecules. Loaded but not free receptors for complement and the Fc portion of IgG co-cap independently with cross-linked surface Ig

We have investigated the possible physical interactions between CR, receptors for the Fc gamma R and surface Ig (sIg) on the surface membrane of murine B lymphocytes. We used the rat mAb to murine CR, 8C12, and 7G6, as CR ligands, and soluble Ag-antibody complexes as FcR ligands; and F(ab')2 fragments of rabbit antibodies specific for mouse IgM and IgD as sIg ligands. We have found that: 1) sIg, CR, and Fc gamma R are not directly linked, because capping of any one did not affect the expression of the others; 2) the mAb 8C12 and 7G6 failed by themselves to cross-link CR; 3) soluble Ag-antibody complexes crosslinked some, Fc gamma R on a minority of Fc gamma R+ lymphocytes; 4) once loaded with anti-CR mAb, CR co-capped with sIg when sIg was cross-linked; 5) once loaded with Ag-antibody complexes, Fc gamma R also co-capped with sIg when sIg was sIg was cross-linked; 6) loading of Fc gamma R did not affect the co-capping of surface CR with cross-linked sIg and conversely, loading of CR did not affect the co-capping of Fc gamma R with cross-linked sIg; only loaded CR or Fc gamma R co-capped with sIg regardless of the status of the other surface molecule; 7) neither loaded nor free CR co-capped with cross-linked Fc gamma R, and neither loaded nor free Fc gamma R co-capped with cross-linked CR. These results demonstrate that both Fc gamma R and CR independently become associated with sIg when either receptor is loaded and sIg is cross-linked.

Interactions between murine B lymphocyte surface membrane molecules. Loaded but not free receptors for complement and the Fc portion of IgG co-cap independently with cross-linked surface Ig

We have investigated the possible physical interactions between CR, receptors for the Fc gamma R and surface Ig (sIg) on the surface membrane of murine B lymphocytes. We used the rat mAb to murine CR, 8C12, and 7G6, as CR ligands, and soluble Ag-antibody complexes as FcR ligands; and F(ab')2 fragments of rabbit antibodies specific for mouse IgM and IgD as sIg ligands. We have found that: 1) sIg, CR, and Fc gamma R are not directly linked, because capping of any one did not affect the expression of the others; 2) the mAb 8C12 and 7G6 failed by themselves to cross-link CR; 3) soluble Ag-antibody complexes crosslinked some, Fc gamma R on a minority of Fc gamma R+ lymphocytes; 4) once loaded with anti-CR mAb, CR co-capped with sIg when sIg was cross-linked; 5) once loaded with Ag-antibody complexes, Fc gamma R also co-capped with sIg when sIg was sIg was cross-linked; 6) loading of Fc gamma R did not affect the co-capping of surface CR with cross-linked sIg and conversely, loading of CR did not affect the co-capping of Fc gamma R with cross-linked sIg; only loaded CR or Fc gamma R co-capped with sIg regardless of the status of the other surface molecule; 7) neither loaded nor free CR co-capped with cross-linked Fc gamma R, and neither loaded nor free Fc gamma R co-capped with cross-linked CR. These results demonstrate that both Fc gamma R and CR independently become associated with sIg when either receptor is loaded and sIg is cross-linked.

Human polyclonal and monoclonal IgG and IgM complement 3 nephritic factors: evidence for idiotypic commonality

Complement 3 nephritic factors (C3NeF) were isolated from the sera of patients with membranoproliferative glomerulonephritis (MPGN) and the supernatants of pokeweed mitogen-stimulated mononuclear cells from patients with MPGN. Three human monoclonal C3NeF antibodies (two IgGs, CK and PH, and one IgM, K3C4) were established. Using an exhaustive series of affinity columns, we isolated anti-C3NeF idiotypic antibodies (anti-IdNeF) (three from normal and two from patient sera). Anti-IdNeF preparations bound to F(ab')2-NeF and prevented its ability to stabilize C3bBb convertase. We have used the above reagents to address questions on the genesis and the diversity of C3NeF antibodies. The following results were obtained: All anti-IdNeF preparations bound to C3NeF isolated from patient sera, cell culture supernatants, and IgG and IgM monoclonal C3NeF. None of the monoclonal C3NeF bound to an extensive battery of common antigens, including Fc portion of IgG, TNP, beta-galactosidase, DNA, and bacterial products. These data indicate that C3NeF express one common idiotype and that these antibodies are not raised in response to an obvious antigen.

Use of adenine nucleotide derivatives to assess the potential of exo-active-site-directed reagents as species- or isozyme-specific enzyme inactivators. 3. Synthesis of adenosine 5'-triphosphate derivatives with N6- or 8-substituents bearing iodoacetyl groups

Several series of N6- or 8-substituted derivatives of adenosine 5'-triphosphate (ATP) were synthesized. N6-(omega-Aminoalkyl) derivatives of adenosine 5'-monophosphate (AMP) were converted into their omega-N-carbobenzyloxy derivatives, and these were converted, via the 2',3'-O-carbonyl derivatives of their 5'-phosphorimidazolidates, into the corresponding ATP derivatives. Hydrogenolytic removal of the carbobenzyloxy groups, followed by iodoacetylation of the omega-amino groups with N-(iodoacetoxy)succinimide, gave N6-R-ATP, where R = (CH2)nNHCOCH2I (n = 2--8) or (CH2)nCON)CH3)(CH2)mN(CH3)CO(CH2)nNHCOCH2I (n = m = 3; n = 3, m = 4; n = 4, m = 3; n = m = 4). Condensation of N6-(omega-aminoalkyl) derivatives of AMP with N-hydroxysuccinimide esters of omega-[N-(carbobenzyloxy)amino] carboxylic acids gave N6-(CH2)nNHCO(CH2)mNH-Cbz derivatives of AMP which, upon conversion to the corresponding derivatives of ATP, followed by removal of the carbobenzyloxy group and iodoacetylation, as described above, gave N6-(CH2)nNHCO(CH2)mNHCOCH2I-ATP derivatives (n = 3, m = 5 or 6; n = 4, m = 5; n = 6, m = 1--6). The same sequence of reactions starting with N6-[omega-(methylamino)alkyl] derivatives of N6-CH3-AMP gave N6-CH3, N6-(CH2)nH(CH3)CO(CH2)mNHCOCH2I derivatives of ATP (n = 4, m = 3, 5 or 6; n = 6, m = 5 or 6). Reaction of alpha, omega-diaminoalkanes with 8-Br-ATP gave 8-NH(CH2)nNH2 derivatives of ATP, which upon iodoacetylation gave 8-NH(CH2)nNHCOCH2I derivatives of ATP (n = 2, 4, 6, or 8). Substrate and inhibitor properties indicated that the ATP derivatives are potential exco-ATP-site-directed inactivators of hexokinases, adenylate kinases, and pyruvate kinases.

Use of adenine nucleotide derivatives to assess the potential of exo-active-site-directed reagents as species- or isozyme-specific enzyme inactivators. 5. Interactions of adenosine 5'-triphosphate derivatives with rat pyruvate kinases, Escherichia coli thymidine kinase, and yeast and rat hexokinases

Adenosine 5'-triphosphate (ATP) derivatives of the types N6-R-ATP [R = (CH2)nNHCOCH2I, (CH2)nNHCO-(CH2)mNHCOCH2I, or (CH2)nCON(Me)(CH2)mN(Me)CO(CH2)nNHCOCH2I], N6-Me-N6-R-ATP [R = (CH2)nN-(Me)CO(CH2)mNHCOCH2I], and 8-R-ATP [R = NM(CH2)nNHCOCH2I] with 5--19 spacer atoms between N6 or C-8 and iodine have been evaluated as potential exo-ATP-site-directed reagents for phosphokinases. Substrate and inhibitor properties indicated that the compounds possessed affinity for the ATP sites of the muscle (M), kidney (K), and liver (L) isozymes of rat pyruvate kinase (PK), of E. coli thymidine kinase (TK), and of yeast hexokinase (HK) and rat KH I, II, and III isozymes. Tests for time-dependent loss of enzyme activity (inactivation) were performed under conditions in which a large proportion of each phosphokinase was present as an enzyme-inhibitor complex. No ATP-site-directed inactivations resulted when the M, L, or K isozymes of PK were exposed for 8 h, 22 degrees C, to 5 mM levels of 18 ATP derivatives or 6 analogous ADP derivatives or when yeast HK or rat KH I, II, or III was exposed for 6 h, 22 degrees C, to 5 mM levels of 28 ATP derivatives. Escherichia coli TK was inactivated by 6 of 25 ATP derivatives tested at 10 mM, 6 h, 0 degrees C; inactivation was slowed by MgATP in the case of N6-CH3-N6-R-ATP [R = (CH2)4N(CH3)CO(CH2)5NHCOCH2I]. Only 1% of 298 enzyme-inhibitor combinations exhibited ATP-site-directed inactivation, signifying that few suitably positioned and sufficiently reactive nucleophilic groups were present near the enzymic ATP sites. Studies have now shown that exo-active-site-directed reagents can act as isozyme- or species-selective enzyme inhibitors. The present survey indicates that in many cases such reagents may be difficult of access when data are not available regarding structural or physicochemical features of the target enzyme adjacent to its catalytic site.

Formation of ribonucleotide 2',3'-cyclic carbonates during conversion of ribonucleoside 5'-phosphates to diphosphates and triphosphates by the phosphorimidazolidate procedure

Ribo- and 2'-deoxyribonucleoside 5'-di- or triphosphates are commonly synthesized by reaction of inorganic phosphate or pyrophosphate with phosphorimidazolidates obtained by reaction of nucleoside 5'-phosphates with 1,1'-carbonyldiimidazole. The latter reaction, however, converted UMP, CMP, IMP, GMP, and AMP in high yield to the 2',3'-cyclic carbonate derivatives of their phosphorimidazolidates. Acidic treatment of the product from AMP gave AMP 2',3'-cyclic carbonate dihydrate; this was characterized by its uv, ir, and pmr spectra and by its conversion to adenosine 2',3'-cyclic carbonate by acid phosphatase and to AMP by basic hydrolysis. ADP or ATP synthesized by the phosphorimidazolidate method contained equal or greater amounts of their respective 2',3'-cyclic carbonates. The latter could be quantitatively converted to ADP and ATP, respectively, by 4-hr hydrolysis at pH 10.5, 22 degrees. ADP or ATP can be synthesized without concomitant 2',3'-cyclic carbonate formation by reaction of AMP with phosphorimidazolidates of inorganic phosphate or pyrophosphate.