Abstract A41: Small molecule inhibition of PTPN2/1 inflames the tumour microenvironment and unleashes potent CD8+ T cell immunity

Immune checkpoint blockade is effective for a subset of patients across many cancers, but most patients are refractory to current immunotherapies and new approaches are needed to overcome resistance. The protein tyrosine phosphatase PTPN2 is a central regulator of inflammation, and genetic deletion of PTPN2 on either tumour cells or host immune cells promotes anti-tumour immunity. However, inhibitors of PTPN2 with suitable pharmacokinetic properties for oral administration have not been described. Here, we present the characterization of ABBV-CLS-484 (A484), a potent active site inhibitor of PTPN2 and the closely related phosphatase PTPN1. A484 treatment in vitro amplifies the response to interferon gamma, and monotherapy A484 treatment generates robust anti-tumour immunity in several murine cancer models. Through in vivo studies and single cell transcriptional profiling of tumour-infiltrating lymphocytes (TIL) from A484-treated mice, we show that A484 inflames the tumour microenvironment and promotes CD8+ T cell function by enhancing cytokine signaling and decreasing T cell exhaustion and dysfunction. Our results demonstrate that oral administration of small molecule inhibitors of PTPN2/N1 can induce potent anti-tumour immunity in mouse models. PTPN2/N1 inhibitors offer a promising new strategy for cancer immunotherapy and are currently being evaluated clinically in patients with advanced solid tumours (NCT04777994). More broadly, our study shows that small molecule inhibitors of key intracellular immune regulators can achieve efficacy comparable to current antibody-based immune checkpoint blockade in preclinical models. Finally, to our knowledge A484 represents the first active-site phosphatase inhibitor to enter clinical evaluation for cancer immunotherapy and may pave the way for additional therapeutics targeting this important class of enzymes.

Citation Format: Hakimeh Ebrahimi-Nik, Arvin Iracheta-Vellve, Kira E. Olander, Thomas R.G. Davis, Sarah Y. Kim, Mitchell D. Yeary, James C. Patti, Tyler M. Balon, Omar Ismail Avila, Cun Lan Chuong, Meng-Ju Wu, Christina K. Baumgartner, Keith M. Hamel, Kathleen A. McGuire, Rebecca Mathew, Carey Backus, Ian C. Kohnle, Zhaoming Xiong, Elliot P. Farney, Jennifer M. Frost, Geoff T. Halvorsen, Matthew Rees, Andrew Boghossian, Melissa Ronan, Jennifer A. Roth, Todd R. Golub, Gabriel K. Griffin, Nabeel El-Bardeesy, Clay C. Beauregard, Philip R. Kym, Kathleen B. Yates, Robert T. Manguso. Small molecule inhibition of PTPN2/1 inflames the tumour microenvironment and unleashes potent CD8+ T cell immunity [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A41.

Combining bio-telemetry and underwater imagery to elucidate the reproductive behaviour of a large, long-lived Australian freshwater teleost

Murray cod Maccullochella peelii (Mitchell) have a key ecological role in ensuring the health of Australia's largest inland waterway, but many aspects surrounding its reproductive strategies in the wild are unknown. From 2015 to 2019 within the Northern Murray-Darling Basin, Australia, we used a combination of bio-telemetry and underwater imagery to quantify the behaviour of Murray cod across their breeding cycle in a natural riverine environment. In most years, breeding behaviour including nest site selection was observed from early-August and spawning from late-August through to late-October, which is considerably earlier than previously reported. There was a positive correlation between the onset of breeding behaviour and week-of-year, and spawning was correlated with moon-phase. Whilst some nesting sites were amongst woody debris and in hollow logs, the majority were located in shallow water on hard substrate underneath undercuts along the riverbank edge. Nests were frequently established in isolated and disconnected pools with little or no measurable flow, suggesting that river hydraulics is not a key component driving spawning of Murray cod across at least some areas of its range. Larvae were observed actively swimming and controlling their position within and near nests and used a scatter tactic when dispersing. We also established that disturbing nesting Murray cod had a negative impact on egg and larval survival. We suggest a review of current regulations to safeguard the long-term conservation of the species across all sections of its range.

Climate refugia for kelp within an ocean warming hotspot revealed by stacked species distribution modelling

Canopy forming macroalgae are declining globally due to climate change and the identification of refuges for these habitats is crucial for their conservation. This is particularly pertinent in ocean warming hotspots where significant range contractions of kelp have occurred and are projected to continue. We developed a stacked urchin-kelp species distribution model (SDM) to predict climate refugia for kelp (Ecklonia radiata) in an ocean warming hotspot, south-eastern Australia. The optimal stacked-SDM incorporated biotic and abiotic explanatory covariates and was validated using an independent dataset. Density of the urchin Centrostephanus rodgersii, summer bottom temperature and photosynthetically available radiation at the seabed were significant predictors of kelp cover, highlighting the physiological and ecological influence of these variables on the distribution of kelp. Our optimal stacked-SDM predicted three spatially distinct refuge areas, where kelp occurs in deeper waters than surrounding seascapes. The presence of kelp at two of these refuge areas was confirmed using independent data. The identification of these refuge areas is crucial for conservation, as they are likely to facilitate the persistence of ecologically and economically important kelp forests as waters warm in shallow areas and kelp retreat to depth under climate change. Furthermore, identification of refugia will enable proactive spatial planning that prioritises new locations for protection to ensure that key kelp habitats can persist in a future of increasing stress.

The treatment of dorsal fracture-dislocation of the proximal interphalangeal joint by closed reduction and Kirschner wire fixation: a 16-year follow up

Ten patients who had sustained 11 unstable dorsal fracture-dislocations of finger proximal interphalangeal joints were reviewed at a mean follow-up of 16 years. All had been treated acutely by closed reduction and transarticular Kirschner wire fixation of the proximal interphalangeal joint, without any attempt at reduction of the fracture of the base of the middle phalanx, which probably involved 30-60% of the articular surface. Seven of the ten patients complained of no finger pain or stiffness, and none complained of severe pain. There was a mean fixed flexion deformity of 8 degrees at the proximal interphalangeal joint, which had a mean arc of movement of 85 degrees. Although subchondral sclerosis and mild joint space narrowing were observed in some instances, there were no severe degenerative changes. These results confirm that this technique is a reliable treatment method for these injuries, and produces satisfactory long-term results.

Trapezial space height after trapeziectomy: mechanism of formation and benefits

Seventy-three thumbs in 67 women with osteoarthritis of the trapeziometacarpal joint were assessed prospectively. The patients were randomly allocated for treatment by either trapeziectomy alone (n = 26) or trapeziectomy with tendon interposition (n = 23) or ligament reconstruction (n = 24). A K-wire was passed through the thumb metacarpal base and across the trapezial space into the distal pole of the scaphoid in all procedures; this held the base of the metacarpal away from the scaphoid for 4 weeks. Standard thumb radiographs were used to calculate the trapezial space ratio before surgery and at 1-year follow-up examination. The trapezial space ratio decreased significantly from a preoperative mean of 0.40 (range, 0.20-0.56) to a mean of 0.18 (range, 0.08-0.30) after trapeziectomy, 0.16 (range, 0.07-0.30) after trapeziectomy with tendon interposition, and 0.20 (range, 0.00-0.33) after trapeziectomy with ligament reconstruction. There was no significant difference between these 1-year follow-up trapezial space ratios, suggesting that the placement of a K-wire across the trapezial void is as effective as tendon interposition or ligament reconstruction in creating a trapezial space in the short term at least. However, the need to create a trapezial space and maintain thumb length is questioned because the trapezial space height did not correlate with thumb strength at 1-year follow-up examination.

Scaphoid blood flow and acute fracture healing. A dynamic MRI study with enhancement with gadolinium

We have investigated whether assessment of blood flow to the proximal scaphoid can be used to predict nonunion in acute fractures of the scaphoid. We studied 32 fractures of the scaphoid one to two weeks after injury, by dynamic fat-suppressed T1-weighted gradient-echo MRI after the intravenous administration of gadopentetate dimeglumine (0.1 mmol/kg body-weight). Steepest slope values (SSV) and percentage enhancement values (%E) were calculated for the distal and proximal fragments and poles. All the fractures were treated by immobilisation in a cast, and union was assessed by CT at 12 weeks. Nonunion occurred in four fractures (12%), and there was no statistically significant difference between the proximal fragment SSV and %E values for the fractures which united and those with nonunion. The difference between the proximal pole SSV and %E values for the union and nonunion groups reached statistical significance (p < 0.05), but with higher enhancement parameters for the nonunion group. Our results suggest that poor proximal vascularity is not an important determinant of union in fractures of the scaphoid.

Ganglia: the patient's perception

This study investigates the concerns of 50 patients with ganglia and their reasons for primary care consultation and referral to a hand unit. Although a minority of patients sought advice and treatment because of pain, more (38%) were concerned about the cosmetic appearance and a significant number (28%) were concerned that their ganglion was a malignant growth. The general practitioners referred 70% of patients to the hand clinic for "excision of the ganglion" and 30% for further "advice and treatment". However, 74% of patients were satisfied with aspiration of the ganglion and general advice.

Outcome of distal radial fractures in young adults

The outcome of 169 fractures of the distal radius in adults under the age of 50 were assessed at least 18 months after injury (mean follow-up, 4.9 years) using a validated, patient-based outcome questionnaire. The questionnaire responses demonstrated that neither the Frykman nor the Mayo classifications of distal radial fractures predicted outcome. Fracture union with more than 10 degrees of dorsal tilt was associated with increased difficulty with everyday activities and work, while union with a step in the radiocarpal articular surface was associated with loss of wrist mobility and difficulty with fine dextrous tasks. No measure of either intra- or extra-articular malunion influenced the severity or frequency of persistent wrist pain.

Factors influencing the outcome of bone grafting surgery for scaphoid fracture non-union

The results of a consecutive series of bone-grafting procedures for non-union of scaphoid fractures were assessed in order to investigate whether the patient's age or the delay between acute fracture and bone-graft surgery influenced the outcome. One hundred and thirty-four patients with a mean follow up of 2.6 years from bone-graft surgery for scaphoid fracture non-union were assessed for post-operative pain and radiographic evidence of union. No association was found between the union rate following surgery and either the patients' ages or the interval between the original injury and subsequent non-union surgery.

Rapid repeat testing of grip strength for detection of faked hand weakness

This study assessed the use of rapid, repeated measurement of grip strength to detect feigned hand weakness. Normal participants, performing with maximum effort or feigning hand weakness, and patients recovering from carpal tunnel surgery were asked to grip a Jamar dynamometer alternately with each hand on ten occasions. The results showed that grip strength fatigued by an average of 23% during the test in the normal participants, 18% in participants faking weakness, and increased by 2% in the carpal tunnel decompression patients. An increase in grip strength after the first effort was found in 39% of normal participants, 52% of participants faking hand weakness and in 69% of the carpal tunnel decompression patients. These results suggest that rapid, repeated measurement of grip strength is not a reliable discriminator of true and faked hand weakness.

Influence of baculovirus-host cell interactions on complex N-linked glycosylation of a recombinant human protein

The conditions required for mammalian-type complex N-linked glycosylation of human proteins produced in insect cells with the baculovirus expression vector system were investigated. Marked alterations to N-linked glycosylation of human placental secreted alkaline phosphatase (SEAP) were observed with different baculovirus species, insect cell lines, and cell culture media. When a recombinant Autographa californica nucleopolyhedrovirus (AcMNPV) was used to produce SEAP in Trichoplusia ni (Tn-4h) cells cultured in serum-free medium, structural analyses indicated <1% hybrid and no complex oligosaccharides attached to SEAP, a typical result with the baculovirus expression vector system. However, when fetal bovine serum was added to the culture medium, 48 +/- 4% of the oligosaccharides were hybrid or complex (but asialylated) glycans. When a recombinant T. ni nucleopolyhedrovirus (TnSNPV) was similarly used to express SEAP in Tn-4h cells cultured in serum-containing medium, only 24 +/- 3% of the glycans contained terminal N-acetylglucosamine and/or galactose residues. In contrast, SEAP produced in Sf9 cells grown in serum-containing medium with AcMNPV contained <1% hybrid oligosaccharides and no complex oligosaccharides. The results illustrate that baculovirus type, host cell type, and the growth medium all have a strong influence on the glycosylation pathway in insect cells, resulting in significant alterations in structures and relative abundance of N-linked glycoforms. Although the addition of sialic acid residues to the SEAP glycans was not detected, possible approaches to obtain sialylated glycans are discussed.

The prognostic value and reproducibility of the radiological features of the fractured scaphoid

We investigated whether the radiological features of the fractured scaphoid could be reproducibly measured and used to predict the likelihood of union with conservative plaster cast immobilization. We found that the inter- and intra-observer reproducibility of the Compson, Herbert and Russe classification systems were only fair and that none predicted fracture union. Assessments of fracture level, comminution and displacement showed moderate inter- and intra-observer reproducibility but did not predict the likelihood of fracture union. We conclude that the radiological features of acute scaphoid fractures cannot be used to predict the likelihood of fracture union.

Work practices and histopathological changes in the tenosynovium and flexor retinaculum in carpal tunnel syndrome in women

We studied 58 women of employable age with the carpal tunnel syndrome in order to determine whether the histological appearances of the carpal tunnel, tenosynovium and flexor retinaculum are influenced by work practices. Age, body mass index and the duration of symptoms did not correlate with the extent of oedema or fibrosis within the tenosynovium. The incidence of abnormality on histological examination of the tenosynovium was the same in employed and unemployed patients (p = 1.0), and was not influenced by the level of repetition (p = 0.89) or force (p = 0.29) of work. Myxoid degeneration within the flexor retinaculum was, however, more common in women undertaking 'high-force' work. Apart from this finding, the results suggest that work practices do not affect tenosynovial thickening, fibrosis or oedema in patients with carpal tunnel syndrome.

The detection of feigned hand weakness using the five position grip strength test

This study assessed the sensitivity and specificity of the five-position grip strength test (5PGST) for detecting feigned hand weakness in healthy volunteers. The 5PGST reliably detected feigned hand weakness in only 15% of cases. Thirty-three per cent of volunteers demonstrated an entirely normal pattern of grip strength when feigning weakness.

Follow-up after carpal tunnel decompression - general practitioner surgery or hand clinic? A randomized prospective study

We prospectively randomized 100 patients following carpal tunnel decompression who were having a 2-week postoperative assessment and removal of stitches to either their local general practitioner (GP) or the hospital outpatient department. All patients were seen at hospital 6 weeks postoperatively for a final assessment. The waiting time for assessment and suture removal was shorter at the GP surgery than in the outpatient department (mean 13 min and 28 min respectively) but significantly more patients were diagnosed as having wound infections (14% and 0% respectively); most were given antibiotics, perhaps unnecessarily.

Do repetitive tasks give rise to musculoskeletal disorders?

Repetitive tasks can undoubtedly cause discomfort and pain, but whether they cause or worsen the pathology causing the pain is most uncertain. Research in this area is difficult as the 'work-related upper limb disorders' do not occur exclusively in workers and because there is no simple, reliable and reproducible test for most 'work-related upper limb disorders'. Furthermore many studies are difficult to interpret as they detect disease by the presence of symptoms: one would expect manual workers to complain of more symptoms than sedentary workers and symptom aggravation does not tell one anything about the causation of the underlying pathology.

A prospective study of two conservative treatments for ganglia of the wrist

This randomized prospective study assessed whether multiple puncture of the ganglion wall improves the results of simple ganglion aspiration. We found that 32% of ganglia resolved after aspiration alone in comparison with 22% after aspiration and multiple puncture. This difference was not significant. However, only 18% of patients requested formal surgical excision, suggesting that aspiration allays fears of malignancy and allows the patient to accept a minor cosmetic embarrassment.

Percutaneous intramedullary fixation of metacarpal shaft fractures

Twenty-two displaced metacarpal shaft fractures in 19 patients were stabilized with multiple intramedullary K-wires. These were inserted percutaneously through a small window in the base of the metacarpal and were buried in the bone. No external splintage was routinely used postoperatively and all patients were encouraged to mobilize their fingers immediately: formal physiotherapy was not usually required. All the fractures that we were able to follow-up united, but the K-wires bent at the fracture site in two instances, producing 20 degrees angular deformities. The buried K-wires had to be removed in one instance as a result of protrusion into the carpometacarpal joint.

Acute fractures of the scaphoid. Treatment by cast immobilisation with the wrist in flexion or extension?

Acute fractures of the scaphoid were randomly allocated for conservative treatment in a Colles'-type plaster cast with the wrist immobilised in either 20 degrees flexion or 20 degrees extension. The position of the wrist did not influence the rate of union of the fracture (89%) but when reviewed after six months the wrists which had been immobilised in flexion had a greater restriction of extension. We recommend that acute fractures of the scaphoid should be treated in a Colles'-type cast with the wrist in slight extension.

Dupuytren's disease and frozen shoulder induced by treatment with a matrix metalloproteinase inhibitor

In a series of 12 patients with inoperable gastric carcinoma who had treatment with a synthetic matrix metalloproteinase inhibitor (Marimastat) for more than one month, six developed a frozen shoulder or a condition resembling Dupuytren's disease. This suggests that the matrix metalloproteinases, a family of naturally occurring proteinases, may be involved in the pathogenesis of these two conditions. Our observation opens avenues for further research which could lead to local or systemic therapeutic interventions for frozen shoulder and Dupuytren's disease.

Is occupation an aetiological factor in the development of trigger finger?

We investigated the occupation histories of 178 patients with idiopathic trigger finger. When compared with the 1991 Census data, the distribution of their occupations was not significantly different from the local general population. It is concluded that the vast majority of trigger fingers develop for reasons other than occupation.

Pollicisation of the index finger. A 27-year follow-up study

We have reviewed 11 patients with congenital absence of the thumb, treated by pollicisation of the index finger, after follow-up for 20 to 38 years. Seven of the hands also had an associated radial club-hand deformity. Function as assessed by the Percival score was excellent in six, good in three, fair in two and poor in four; three of the poor results were in patients with radial club hand. Ten of the 15 transfers were used as normal thumbs, but in five hands function required trick movements. Of the seven unilateral cases, two transplants were used as the dominant hand, and in another two thumb strength was more than 50% of that on the opposite side. For patients with isolated congenital absence of the thumb, pollicisation of the index finger gives good functional and cosmetic results which are maintained. The results are less reliable for those with radial club hand.

Baculovirus expression of an insect gene that encodes multiple neuropeptides

Sex pheromone production in the corn earworm, Helicoverpa zea, is regulated by a 33-amino-acid neuropeptide named Hez-PBAN (pheromone biosynthesis activating neuropeptide). Hez-PBAN is encoded in a preprohormone that also contains four other structurally related peptides. Two recombinant baculoviruses that contain two different sequences of Hez-PBAN cDNA under the control of a strong polyhedrin promotor were constructed. The first virus, AcWT-PBAN, contains the entire prepro-Hez-PBAN coding sequence. The second virus, AcBX-PBAN, contains a synthetic chimera gene encoding a bombyxin signal peptide sequence fused to a pro-Hez-PBAN sequence. Cell extracts, culture medium of BTI-TN-5B1-4 cells, and hemolymph from 4th instar Trichoplusia ni larvae, all infected with AcBX-PBAN, showed a high level of pheromonotropic activity. Pheromonotropic activity was not detected in the cells infected with AcWT-PBAN. Results of chromatographic and immunochemical studies showed that some of the potential processing sites in the expressed pro-Hez-PBAN sequence were not used during posttranslational processing in the AcBX-PBAN-4-infected BTI-TN-5B1-4 cells and 4th instar T. ni larvae. However, the processing pattern of the recombinant pro-Hez-PBAN in AcBX-PBAN-infected 4th instar T. ni larvae was similar to that exhibited in the central nervous system of H. zea adult females, since a PBAN-like immunoreactive-peptide-band was found in the hemolymph of Ac-BX-PBAN-4-infected 4th instar T. ni larvae. In a droplet feeding assay, neonate and 3rd instar T. ni larvae infected with AcBX-PBAN-4 showed a significant reduction in survival time (26% and 19%, respectively) when compared to control larvae that were infected with a polyhedrin-deficient virus, Ac-E10.

Conservatively managed tibial shaft fractures in Nottingham, UK: are pain, osteoarthritis, and disability long-term complications?

OBJECTIVES

To investigate longterm pain and disability subsequent to a tibial shaft fracture treated conservatively.

DESIGN AND SETTING

Subjects who had sustained a tibial shaft fracture more than 27 years ago were compared with those who had not.

SUBJECTS

572 fracture patients (identified from the records of the plaster room) aged over 16 at the time of injury were contracted and were compared with 2285 randomly selected subjects matched for age, sex, and general practice.

MAIN OUTCOME MEASURES

Self reported knee pain; self reported GP's diagnosis of osteoarthritis; ability to climb stairs, walk 100 yards, to bend, kneel, or stoop; and SF-36 physical functioning score.

RESULTS

Subjects were reviewed between 27 and 41 years after tibial shaft fracture (mean 35 years). Fracture patients were more likely to suffer chronic knee pain (odds ratio 1.23; 95% confidence interval (CI) 1.00, 1.51) and report being given a diagnosis of osteoarthritis by their GP (odds ratio 1.46; 95% CI 1.08, 1.97). The ability to climb stairs, walk 100 yards, and bend, kneel, or stoop was less in the fracture group than the other subjects. The SF-36 physical function score was significantly lower in the fracture group.

CONCLUSIONS

More than 27 years after a tibial shaft fracture, subjects have more knee pain than the rest of the population. They also have greater difficulty performing everyday physical activities. The excess morbidity may be due to injury factors or treatment factors, and further research is needed to investigate this important association further.

Trapeziectomy alone, with tendon interposition or with ligament reconstruction?

This randomized prospective study compared the results of trapeziectomy alone, or combined with tendon interposition or ligament reconstruction in 76 women with basal thumb osteoarthritis. At 3 month and 1 year follow-up the results of the three procedures were indistinguishable in terms of pain relief, hand function and thumb strength. In the short term at least, tendon interposition and ligament reconstruction do not improve the results of trapeziectomy.

Conservative management of wrist ganglia. Aspiration versus steroid infiltration

Wrist ganglia were randomly allocated for conservative treatment by either aspiration or aspiration and injection of steroid. Both treatment methods had 33% success rates. Almost all ganglia which recurred after one aspiration did not resolve with further aspirations. After aspiration and explanation of the benign nature of ganglia, only a quarter of patients requested surgical treatment.

A comparison of the relative costs of cast treatment and intramedullary nailing for tibial diaphyseal fractures in the UK

A retrospective study was undertaken to compare the costs of treating tibial diaphyseal fractures non-operatively in a cast or operatively with locked intramedullary nailing. In total 39 patients with isolated closed or grade I open, two-part, displaced tibial diaphyseal fractures were studied. Of these, 18 were treated by manipulation under anaesthesia and cast immobilization, and 21 by closed, reamed, locked intramedullary nailing. A detailed analysis of the cost of treatment of each patient was performed and analysed in terms of the in-hospital costs and the overall costs, taking into account time off work. The mean hospital costs were 2226 pounds for plaster treatment and 3727 pounds for intramedullary nailing (significantly different, p < 0.05). The mean time off work was 9 weeks longer in the plaster group and when the cost of lost production through time off work was added to the hospital costs, the overall costs of plaster treatment and intramedullary nailing were 6810 Pounds and 6592 Pounds (difference not significant). This study suggests that the cost to the hospital of treating these fractures is less with plaster treatment but that the overall cost to the community is no different.

Palmar plate interposition (Tupper) arthroplasty for post-traumatic metacarpophalangeal osteoarthritis

We report the results of five interposition palmar plate (Tupper) arthroplasties for post-traumatic or post-infection osteoarthritis of metacarpophalangeal joints. All were pain free at a median follow-up of 4 years. The mean arc of joint flexion was 55 degrees and finger to thumb tip pinch was 60% of normal. All patients had reduced grip strength, but were satisfied with the procedure.

In vitro characterization of a Trichoplusia ni single nucleocapsid nuclear polyhedrosis virus

A Trichoplusia ni single nucleocapsid nuclear polyhedrosis virus (TnSNPV) isolate was cloned and its replication studied in the BTI-Tn-5B1-4 insect cell line. The BTI-Tn-5B1-4 cells were highly susceptible to TnSNPV infection, with 99% of the cells containing viable polyhedra by 30 h post-inoculation. Viral DNA synthesis was detected by 9 h post-infection (p.i.). Infectious budded virus (BV) was first detected at 13 h p.i. and reached an average maximum titre of 3.875 x 10(6) p.f.u./ml 27 h p.i. A total of 25 BV structural proteins having apparent molecular masses ranging from 27.5 kDa to 86 kDa were identified. Using [35S]methionine pulse-labelling, 19 virus-induced proteins with molecular masses ranging from 27 kDa to 106 kDa were detected from 4 to 28 h p.i. Host cell protein synthesis continued throughout virus replication, although at gradually decreasing rates. Thirty-two structural proteins of occlusion-derived virus ranging in apparent molecular masses from 11 kDa to 98 kDa were identified using silver staining procedures. Digestion of viral DNA with the restriction endonucleases EcoRI, HindIII and BamHI generated 31, 26 and 12 fragments, respectively. Estimates for the molecular mass of the TnSNPV genome ranged from 115.5 to 119.2 kbp. In bioassays performed with neonate T. ni larvae, the mean LD50s for the TnSNPV and Autographa californica MNPV were 1.5 (+/- 0.3) and 11.0 (+/- 4.0) polyhedra per larva, respectively.

Intrinsic glycosylation potentials of insect cell cultures and insect larvae

The glycosylation and subsequent processing of native and recombinant glycoproteins expressed in established insect cell lines and insect larvae were compared. The Spodoptera frugiperda (Sf21) and Trichoplusia ni (TN-368 and BTI-Tn-5B1-4) cell lines possessed several intrinsic glycoproteins that are modified with both N- and O-linked oligosaccharides. The N-linked oligosaccharides were identified as both the simple (high mannose) and complex (containing sialic acid) types. Similarly, the T. ni larvae also possessed intrinsic glycoproteins that were modified with O-linked and simple and complex N-linked oligosaccharides. Additionally, human placental, secreted alkaline phosphatase (SEAP) produced during replication of a recombinant baculovirus in T. ni larvae was modified with complex oligosaccharide having sialic acid linked alpha(2-6) to galactose.

Results of extensor tendon repair performed by junior accident and emergency staff

The results of 46 extensor tendon repairs performed by junior accident and emergency doctors were assessed, with a minimum follow up of 6 months. Based on Miller's assessment, 80 per cent of the proximal injuries achieved excellent or good results. Only 18 per cent of distal injuries achieved excellent or good results. Neither grip or fingertip pinch strength were significantly reduced. Sixty-seven per cent of patients complained of no residual pain and only 7 per cent complained of the injured digit getting in the way.

Clinical signs in scaphoid fractures

In a prospective study we investigated 12 clinical features for scaphoid fractures in 52 patients: 23 in whom a fracture of the scaphoid was diagnosed radiologically and 29 patients in whom a fracture was clinically suspected but could not be confirmed by radiography or scintigraphy. The signs were tested within a few days of injury and again 2 weeks later. None was reliable in diagnosing a scaphoid fracture.

Scintigraphy in the evaluation of the "clinical" scaphoid fracture

In a prospective study we performed bone scans on 84 patients who had sustained a wrist injury and in whom a scaphoid fracture was clinically suspected but could not be confirmed on the original set of five routine "scaphoid view" radiographs. In 40 patients the bone scan was normal and in 25 there was increased uptake in areas other than the scaphoid. In 19 there was localized increased uptake in the scaphoid bone. In seven of these a scaphoid fracture was subsequently demonstrated on repeat radiographs (five cases) or a CT scan (two cases). In the remaining 12 no fracture could be demonstrated.

Excision of the trapezium for osteoarthritis at the base of the thumb

We have assessed the results of 34 simple excisions of the trapezium, with no additional soft-tissue procedures, in 30 patients. At a median follow-up of five years (2 to 22), 16 thumbs (47%) were completely painfree and a further 10 (29%) were slightly painful after use. Nineteen thumbs (56%) had no functional disability, but thumb-pinch strength was reduced by about 20%. No patient had painful degeneration at the scaphotrapezial pseudarthrosis.

Excision of the trapezium for osteoarthritis at the base of the thumb

We have assessed the results of 34 simple excisions of the trapezium, with no additional soft-tissue procedures, in 30 patients. At a median follow-up of five years (2 to 22), 16 thumbs (47%) were completely painfree and a further 10 (29%) were slightly painful after use. Nineteen thumbs (56%) had no functional disability, but thumb-pinch strength was reduced by about 20%. No patient had painful degeneration at the scaphotrapezial pseudarthrosis.

The prevalence of degenerative arthritis of the base of the thumb in post-menopausal women

The prevalence of basal thumb osteoarthritis was assessed in 143 post-menopausal women. The radiological prevalences of isolated carpometacarpal and scapho-trapezial osteoarthritis were 25% and 2% respectively. The prevalence of combined carpometacarpal and scapho-trapezial osteoarthritis was 8%. 28% of women with isolated carpometacarpal osteoarthritis and 55% with combined carpometacarpal and scapho-trapezial osteoarthritis complained of basal thumb pain.

Volar dislocation of the lunate causing multiple flexor tendon ruptures. An unusual manifestation of pyrophosphate arthropathy

A case of volar dislocation of the lunate, associated with multiple rupture of the flexor tendons of the fingers, is described in a 76-year-old man with calcium pyrophosphate arthropathy.

The effects of acidosis and alkalosis on long bone vascular resistance

This study used an ex vivo perfusion model to investigate the direct effects of acidosis and alkalosis on the vascular resistance of the canine tibia. Baseline vascular resistance (BVR) and the vascular smooth muscle response to bolus doses of norepinephrine (NE) (0.025-3.2 nmol) and periarterial sympathetic nerve stimulation (NS) (10-25 Hz: 9 V, 2 ms pulses, 10 s) were studied. In Group I, these parameters were measured at normal pH (duration 7.34-7.44) and then during acidosis (pH 7.2-7.33). In Group II, they were measured at normal pH and then during alkalosis (pH 7.47-7.58). In Group III (control), they were measured serially at a normal pH. Alkalosis increased BVR by 56% (p < 0.0001). Acidosis attenuated (18% reduction) and alkalosis enhanced (66% increase) the vasoconstrictor action of NE (p < 0.0001). Acidosis also attenuated (11% reduction) the effect of sympathetic NS (p = 0.012). It is concluded that perfusion pH influences the sensitivity of long bone resistance vessels to circulating NE and sympathetic NS. Thus, local concentration of hydrogen ions may provide bone with a mechanism to autoregulate blood flow.

Comparison of oligosaccharide processing among various insect cell lines expressing a secreted glycoprotein

The processing of the N-linked oligosaccharide modifying a secreted alkaline phosphatase glycoprotein (SEAP) expressed with a recombinant Autographa californica nuclear polyhedrosis virus was evaluated in insect cell lines established from Spodoptera frugiperda, Trichoplusia ni, and Mamestra brassicae. Studies with Endoglycosidase H (Endo H), which removes high-mannose oligosaccharides, revealed that 79% of the intracellular SEAP produced in the M. brassicae-derived MB0503 cell line was Endo H resistant. The commonly used S. frugiperda Sf21 and Sf9 cell lines produced 44 and 21% Endo H-resistant intracellular SEAP, respectively. Detection of oligosaccharide moieties with lectins, which selectively recognize terminal sugars, identified only mannose residues on SEAP expressed in the six insect cell lines. However, the oligosaccharide moiety of SEAP expressed in a Chinese hamster ovary cell line contained sialic acid. Therefore, when expressed in mammalian cells, the oligosaccharide present on SEAP is processed into complex oligosaccharide, but in insect cells it is of the high-mannose type. Studies with inhibitors of the initial oligosaccharide processing steps demonstrated that all six cell lines possessed glycosidase I/II and mannosidase I activity and that glycosylation was required for secretion.

Comparative recombinant protein production of eight insect cell lines

A recombinant Autographa californica baculovirus expressing secreted alkaline phosphatase (SEAP) gene was used to evaluate the expression of a secreted glycoprotein in eight insect cell lines derived from Spodoptera frugiperda, Trichoplusia ni, Mamestra brassicae and Estigmene acrea. Because cell density was found to influence protein production, SEAP production was evaluated at optimal cell densities for each cell line on both a per cell and per milliliter basis. On a per cell basis, the T. ni-derived BTI-TN-5B1-4 cells produced a minimum of 20-fold more SEAP than the S. frugiperda-derived Sf9 or Sf2l cell lines and a minimum of 9-fold more than any of the other cell lines growing in serum-containing medium. On a per milliliter basis, BTI-TN-5B1-4 cells produced a minimum of fivefold more SEAP than any of the other cell lines tested. Using cell lines that were adapted to serum-free medium, SEAP yields were the same or better than their counterparts in serum-containing medium. At 3 days postinoculation, extracellular SEAP activity ranged from 59 to 85% of total SEAP activity with cell lines grown in serum-free and serum-containing media.

Baculovirus Expression of Alkaline Phosphatase as a Reporter Gene for Evaluation of Production, Glycosylation and Secretion

We have devised a simple and efficient baculovirus expression vector system to evaluate insect tissue culture cells for their capacity to express, glycosylate and secrete foreign proteins. A truncated placental alkaline phosphatase (SEAP) gene was inserted into the Autographa californica nuclear polyhedrosis virus (AcMNPV) genome under the transcriptional control of the polyhedrin gene promoter. Production levels, glycosylation, and secretion of the recombinant protein were examined in Trichoplusia ni (BTI-TN-5B1-4) and Spodoptera frugiperda (Sf9) cell lines. The assay for SEAP activity, which is fast, inexpensive, and quantitative to concentrations of 20 picograms per milliliter, was used to assess cell-associated and secreted SEAP activity. The proportion of SEAP which is modified with N-linked oligosaccharide can also be determined due to the difference in mobilities during SDS-PAGE between the glycosylated and nonglycosylated forms of the protein.

Xenon washout from the rabbit femur during short hyperbaric exposures

133Xenon washout from the femora of 5 anesthetized rabbits was recorded during short hyperbaric exposures (3 atm abs). Equipment tests showed that the scintillation counter was heat sensitive. The recorded count rate from a constant source of 133xenon decreased during compression (temperature rose 5 degrees C) and increased during decompression (temperature fell 5 degrees C). When the scintillation counter was thermally insulated, the rate of xenon washout from the femur remained unchanged in all rabbits during these hyperbaric exposures. The conclusion is that the rate of xenon washout from the femur is not affected by changes in ambient pressure. As most scintillation counters are heat sensitive, it is possible that the previous report of such changes was erroneous and caused by heat sensitivity of the recording equipment.

Endothelial control of long bone vascular resistance

This in vitro study investigates whether intraosseous endothelial cells can regulate long bone blood flow by secretion of vasodilator prostaglandin and EDRF (endothelium-derived relaxing factor). Canine tibia were perfused through the nutrient artery at a constant flow rate, and the increases in perfusion pressure caused by standard doses of norepinephrine were recorded first under control conditions and then during acetylcholine infusion. Acetylcholine attenuated the norepinephrine pressure responses (-62 +/- 3%). This attenuating effect of acetylcholine was partially abolished by inhibition of prostaglandin synthesis (-20 +/- 6%) and completely abolished by inhibition of EDRF synthesis (+73 +/- 43%) or combined inhibition of prostaglandin and EDRF synthesis (+134 +/- 30%). These results are statistically significant (p less than 0.0001) and suggest that both EDRF and vasodilator prostaglandin are synthesized by intraosseous endothelial cells, and can modify long bone vascular resistance. Thus, as in other organs, intraosseous endothelial cells may provide bone with an autoregulatory control mechanism and enable it to respond to a diverse group of vasodilator stimuli.

A comparison study of pain associated with endocervical sampling techniques

Endocervical curettage (ECC) is an important tool in the diagnosis and treatment of cervical neoplasia. Its use has been limited, however, because of the pain it can cause. We show that the use of a soft plastic curette cause statistically less pain without compromising the quantity or quality of the sample.

The effect of hypothermic ischemia on the alpha-adrenergic mechanisms of the canine tibia vascular bed

The effect of hypothermic ischemia on alpha-1 and -2 adrenergic receptor mediated vasoconstriction has been studied in an in vitro perfused canine tibia preparation. Bones were perfused at a constant rate with aerated (95% O2, 5% CO2) modified Krebs Ringer solution and the effect of bolus injections of norepinephrine (0.025-6.4 nmol) on the perfusion pressure was studied. For all bones the first dose-response curve was produced under control conditions. In one group the second dose-response curve was generated during a constant infusion of prazosin (alpha-1 adrenergic antagonist); in another it was produced during a constant infusion of rauwolscine (alpha-2 adrenergic antagonist); in the control group it was generated under control conditions. The results demonstrate that, after 48 h of hypothermic ischemia, alpha-1 adrenergic-mediated vasoconstriction was significantly attenuated (p less than 0.001). However, alpha-2 adrenergic-mediated vasoconstriction was unaffected by increasing periods of hypothermic ischemia.

The effects of ischemia on long bone vascular resistance

An in vitro canine tibia model was used to assess the effects of 48 h of hypothermic (4 degrees C) ischemia on bone vascular resistance and on responsiveness of intraosseous blood vessels to circulating norepinephrine. Three groups of bones were studied: Group I (n = 11), 48 h hypothermic ischemia; Group II (n = 11), 48 h hypothermic ischemia with pretreatment with allopurinol and oxypurinol; and Group III (n = 10), no ischemia. Resting vascular resistance in both ischemic groups (79 and 74 mmHg/ml/min) was significantly higher (p less than 0.0001) than in the nonischemic group (22 mmHg/ml/min). Effects of norepinephrine on vascular resistance were significantly greater in both ischemic groups (p less than 0.004). In all three groups, acetylcholine infusion attenuated the increases in perfusion pressure caused by norepinephrine. This demonstrates secretion of endothelial-mediated relaxing factors (EDRF) and prostaglandin for up to 48 h of hypothermic ischemia. As no significant differences were detected between the two ischemic groups, this study failed to demonstrate any protective effect of xanthine oxidase inhibitors.