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Levels of misonidazole in human tumours, normal tissues and blood have been measured in patients given a 1g oral dose of drug before surgery or biopsy. The results show that 50--70% of the blood level was found in a wide range of tumours and that similar levels were found in adjacent normal tissues. Good penetration of drug was achieved within tumours, and up to 90--100% of the blood level was found in the necrotic cyst fluid at the centre of some tumours. CSF studies showed free diffusion into the CNS, which was confirmed by finding 50--70% of the blood level within brain tumours. A delay of passage of drugs into the CSF was noted, which was not found for drug diffusion into bile and saliva.

A survey of members of the Federation of Prosthodontic Organizations was done to determine their opinions about various preprosthetic surgical procedures used to treat patients with alveolar atrophy of the maxilla and mandible. In most instances there was lack of consensus, indicating a need for consultation and close cooperation between the oral and maxillofacial surgeon and the prosthodontist in the management of individual patients.

Electron paramagnetic resonance spectroscopy has been used to investigate the structure of the complex of manganous ion with the phosphorylated form of pyruvate,phosphate dikinase (Ep) and the inhibitor oxalate. Oxalate, an analogue of the enolate of pyruvate, is competitive with respect to pyruvate in binding to the phosphorylated form of the enzyme [Michaels, G., Milner, Y., & Reed, G.H. (1975) Biochemistry 14, 3213-3219]. Superhyperfine coupling between the unpaired electrons of Mn(II) and ligands specifically labeled with 17O has been used to identify oxygen ligands to Mn(II) in the complex with oxalate and the phosphorylated form of the enzyme. Oxalate binds at the active site as a bidentate chelate with Mn(II). An oxygen from the 3'-N-phosphohistidyl residue of the protein is in the coordination sphere of Mn(II), and at least two water molecules are also bound to Mn(II) in the complex. Oxalate also binds directly to Mn(II) in a complex with nonphosphorylated enzyme. The structure for the Ep-Mn(II)-oxalate complex implies that simultaneous coordination of a phospho group and of the attacking nucleophile to the divalent cation is likely an important factor in catalysis of this phospho-transfer reaction.

The survival pattern of 60 patients is reported and clinical details given. It has been possible to show significantly poorer survival in those patients whose tumour was incompletely enclosed by the 90% isodose, and the reasons for this have been discussed. The demonstration of pelvic lymph node enlargement has also been shown to be an indicator of poor prognosis.

A modified purification procedure has been developed for dopamine beta-hydroxylase isolated from bovine adrenal medulla. Catalase is included in the homogenization step starting with a suspension of either chromaffin granules or adrenal medulla tissue. With this precaution, the enzyme remains stable in the supernatant solution in preparation for the subsequent purification step involving concanavalin A-Sepharose chromatography. The homogeneous enzyme has a specific activity in the range of 60-70 mumol O2 consumed/min/mg. Using radiolabeled metal ion chelators, it was determined that several of the chelators remained tightly bound to the enzyme after removal of the copper leading to difficulties in establishing stoichiometry of enzyme-bound metal ions.

Pyruvate kinase from rabbit muscle catalyzes an ATP-dependent phosphorylation of glycolate to yield 2-phosphoglycolate (F. J. Kayne (1974) Biochem. Biophys. Res. Commun. 59, 8-13). An investigation of anologous reactions with other alpha-substituted carboxylic acids reveals several new substrates for such a phosphorylation reaction. Thus the alpha-hydroxy carboxylic acids L-lactate, D-lactate, DL-alpha-hydroxybutyrate, DL-alpha-hydroxyvalerate, L-glycerate, D-glycerate, DL-nitrolactate, and DL-beta-chlorolactate are phosphorylated on the alpha-hydroxy group to give the corresponding phosphoesters. Thioglycolate is also a slow substrate for phosphorylation of the thiol group to give the phosphothioglycolate, and DL-thiolactate is phosphorylated in a very slow reaction to give phosphothiolactate. beta-Hydroxypyruvate is a substrate; but, unlike the reaction with pyruvate, with beta-hydroxypyruvate the equilibrium for the reaction lies in favor of ADP and the phosphorylated product which appears from 31P NMR data to be tartronate-semialdehyde-2-phosphate. 31P NMR spectroscopy has been used to verify the identity of the products for all of the reactions. Steady-state kinetic constants have been obtained for some of the more rapid reactions. The reactions with glycolate, L-glycerate, and beta-hydroxypyruvate have kcat values that are close to that for phosphorylation of pyruvate in the reverse of the physiological reaction.

The enhancement of the longitudinal proton relaxation rate of solvent water protons which occurs when Mn(II) is bound to the "tight" metal ion site of unadenylylated glutamine synthetase (GS) was used to determine the binding constant of L-methionine (SR)-sulfoximine to GS-Mn(II) complexes. The binary enhancement for GS-Mn(II) is 22 at 24 MHz, 25 degrees C. The enhancement is lowered in the presence of the sulfoximine and the computed dissociation constant is 30 muM with epsilont, the enhancement for the ternary complex, equal to 3.0. Titration curves for the sulfoximine were also obtained in the presence of Mg-ADP, Mg-ADP plus Pi, and Mg-ATP. The dissociation constants were 9, 5, and 0.8 muM, respectively. The progressive tightening of the dissociation constants is symptomatic of conformational changes at the active site as the total subsite occupied by ATP is filled. The number of rapidly exchanging water molecules drops from 2 to approximately 0.1 when saturating concentrations of L-methionine (SR)-sulfoximine and nucleotide are present. The kinetically determined KI value of approximately 4 muM for the sulfoximine is about three orders of magnitude tighter than thee Km' value of approximately 3 mM for L-glutamate. The previously mentioned dissociation constants obtained by enhancement titrations are also orders of magnitude tighter than Km'. These data suggest that L-methionine (SR)-sulfoximine is a "transition-state" analogue for the glutamine synthetase reaction. ...

Phenylacetone, 4-phenyl-2-butanone, and 4-oxopentyltrimethylammonium chloride were tested as potential transition state analogs for eel acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7). Phenylacetone is a competitive inhibitor of the enzyme but not a transition state analog, since its binding constant is similar to that for the substrate phenyl acetate. 4-Phenyl-2-butanone binds 6-18 times more tightly than the inhibitors 4-phenyl-2-butanol and N-benzylacetamide and the substrate benzyl acetate and also blocks inactivation of the enzyme with methanesulfonyl fluoride. However, its binding is independent of pH in the range 5-7.5, whereas both V and V/Km for benzyl acetate hydrolysis decrease with decreasing pH in this range. These data indicate a specific but weak interaction between the ketone carbonyl and the enzyme, but probably do not justify considering this compound a transition state analog. 4-oxopentyltrimethylammonium iodide has previously been shown to bind about 125 times more strongly than the substrate acetylcholamine. It also binds about 375 times more strongly than the alcohol 4-hydroxypentyltrimethylammonium iodide. Furthermore, the ketone protects the enzyme from inactivation by methansulfony fluoride, while the corresponding quaternary ammonium alcohol accelerates this inactivation reaction. This additional information confirms that the ketone is a transition state analog.

A number of C4--C9 aliphatic ketones are acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) inhibitors, with Ki values in the 0.7--5 mM range. Comparison to analogous substrates would suggest that these ketones are transition state analogs; e.g. 2-pentanone binds to the enzyme approx. 550 times more tightly than ethylacetate. However, a number of other criteria contradict this conclusions: (1) the binding is insensitive to ketone structure: isomeric ketones, cycloalkanones, and sterically hindered ketones have similar inhibitory potencies. (2) Analogous alcohols are also good inhibitors even though they cannot form hemiketals with the enzyme. (3) Representative ketones are relatively ineffective at blocking inactivation of the enzyme by methylsulfonyl fluoride, indicating that ketones do not bind principally at the hydrolytic site. (4) A competition experiment shows that binding of tetramethylammonium chloride excludes binding of 2-pentanone, suggesting that ketones bind to the anionic rather than the hydrolytic site. Thus, observation of tight binding relative to a substrate is not a sufficient criterion to establish that an inhibitor is a transition state analog.

Dopamine beta-hydroxylase was incubated with p-hydroxybenzyl cyanide, ascorbate, and O2 and the products of the hydroxylation reaction were monitored by high performance liquid chromatography. At early times, p-hydroxymandelonitrile was the sole product but this compound slowly decomposed to p-hydroxybenzaldehyde and cyanide. Dopamine beta-hydroxylase was also inhibited under these reaction conditions but the amount of cyanide produced was insufficient to account for the extent of enzyme inhibition. Incubation of dopamine beta-hydroxylase with [ring-3H]p-hydroxybenzyl cyanide, ascorbate, and O2 resulted in incorporation of detectable radiolabel into enzyme only when 100% O2 (0.4 X Km) was present. The amount of incorporated radiolabel was substoichiometric with respect to enzyme subunits (approximately 30%) and also did not correlate with the total amount of inhibited dopamine beta-hydroxylase. These data suggest two different modes of inhibition: covalent-adduct formation at early times and inhibition due to cyanide generated at the active site. Separate K14CN binding studies with dopamine beta-hydroxylase corroborated the latter suggestion since 2 mol of cyanide were bound per tetramer. Tyramine stabilized [14C]cyanide binding to dopamine beta-hydroxylase, consistent with the lack of enzyme reactivation observed under certain conditions (Colombo, G., Giedroc, D. P., Rajashekhar, B., and Villafranca, J. J. 1984) J. Biol. Chem. 259, 1601-1606). EPR data for dopamine beta-hydroxylase-bound Cu2+ directly demonstrated that a quaternary complex with tyramine and cyanide was formed, since the spectrum of dopamine beta-hydroxylase-Cu2+-tyramine-cyanide is distinct from that of dopamine beta-hydroxylase-Cu2+-cyanide and dopamine beta-hydroxylase-Cu2+-tyramine. A comprehensive mechanism for dopamine beta-hydroxylase inhibition by benzyl cyanides is presented.

Ten cases of angiofibroma treated by irradiation are reported. Relief of symptoms occurred by the end of treatment in eight patients. Objective regression was much slower, six having visible disease for greater than 6 months and four for at least 1 year. Only one was symptomatic. Radiological resolution lagged behind clinical improvement and was complete in only one of three asymptomatic patients evaluated by computed tomography (CT) at between 2 and 3 years after treatment. The significance of these residual masses seen on CT is unclear.

Patients with multiple measurable metastases can be used as their own perfectly matched controls to study the effect of different treatments on their metastases. Response to treatment may be assessed by sequential measurement of the regression and regrowth of the metastases and by assessment of the growth delay produced by each treatment. Three patients are described who have been studied in this way to investigate the addition of misonidazole to radiation. The results suggest that it is possible to obtain quantitative data that will discriminate between relatively small doses of radiation and provide interesting clinical information on tumour response. The problems of the method and its possible applications are discussed.

The five enzymes responsible for the conversion of L-aspartate to L-threonine in Escherichia coli were purified to homogeneity and subsequently reconstituted in vitro in ratios approximating those found in vivo. 31P NMR was used to conveniently monitor the rates of consumption of the substrates ATP and NADPH, the accumulation of the intermediates beta-aspartyl phosphate and homoserine phosphate, and the formation of the products ADP, NADP+, and Pi in a single experiment. By this method, the flux of aspartic acid through the enzymes of the pathway was monitored in the absence and in the presence of several alternative substrates and inhibitors. Several known antimetabolites were found to be alternative substrates that ultimately became inhibitors of pathway flux. L-threo-3-Hydroxyaspartic acid was converted to 3-hydroxyhomoserine phosphate by the first four enzymes of the pathway. The antimetabolite L-threo-3-hydroxyhomoserine was found to bind to and inhibit aspartokinase-homoserine dehydrogenase I in a cooperative fashion (I 0.5 = 3 mM, nH = 2.5), similar to the action of the allosteric end product inhibitor L-threonine (I 0.5 = 0.36 mM, nH = 2.4). In the presence of the remaining enzymes of the pathway, however, L-threo-3-hydroxyhomoserine was phosphorylated to the apparent ultimate antimetabolite L-threo-3-hydroxyhomoserine phosphate that was a potent inhibitor of threonine synthase and consequently of L-threonine biosynthesis. When aspartic acid alone was examined as a substrate of the enzymes of the pathway, no accumulation of the beta-aspartyl phosphate and homoserine phosphate intermediates was observed. However, in the presence of either 5 mM L-threo-3-hydroxyhomoserine or 5 mM L-threo-3-hydroxyhomoserine phosphate, homoserine phosphate was found to accumulate. In contrast to the homoserine phosphate and 3-hydroxyhomoserine phosphate intermediates, both of which were very stable, the acylphosphate intermediates beta-aspartyl phosphate and beta-3-hydroxyaspartyl phosphate were highly susceptible to hydrolysis, with first-order rate constants of 4.6 X 10(-3) min-1 and 4.5 X 10(-2) min-1 (pH 7.8, 25 degrees C), respectively.

The coordination sphere of Mn(II) in the complex with GDP and elongation factor Tu from Escherichia coli has been probed by EPR spectroscopy with 17O-labeled ligands. Inhomogeneous broadening in the EPR signals for Mn(II) due to unresolved superhyperfine coupling to the 17O nucleus was used to identify directly bound oxygen ligands. Results with GDP selectively enriched with 17O either in the alpha-phosphate or in the beta-phosphate revealed that GDP was a beta-monodentate ligand for Mn(II) in the complex with the protein. Results with 17O-enriched water showed that two water molecules are coordinated to the Mn(II). The EPR spectrum for the complex is characteristic of octahedral coordination for Mn(II). Hence, three ligands from the protein are required to complete the sextet of ligands.

Over a 2-year period, 17 patients with histologically proven squamous cell carcinoma of the bronchus, assessed as inoperable or incurable on surgical or medical grounds, were treated with palliative radiotherapy and a concurrent 120-h infusion of 5-flurouracil, at a dosage of 1 g/day. The treatment was found to be well tolerated with no major toxicity. The degree of palliation and survival obtained was found to be no different to that of a historical matched control group, treated with radiotherapy alone, with median survival in the two groups of 35 weeks and 42 weeks respectively (log rank test P greater than 0.69). We conclude that although a non-toxic treatment regime, no benefit was obtained by the addition of 5-flurouracil to palliative radiotherapy.

Pyruvate kinase catalyzes the phosphorylation of 3-nitro-2-hydroxypropionate by ATP. The product (3-nitro-2-phosphopropionate) decomposes nonenzymatically and inactivates the enzyme. The inactivation process is irreversible and the enzyme is completely protected against inactivation by mercaptoethanol or the competitive inhibitor oxalate. The Km for 3-nitro-2-hydroxypropionate (DL) is 40 mM and kcat = 5 s-1 at pH 8.6. In terms of kcat/km, 3-nitro-2-hydroxypropionate is a fourfold better substrate than glycolate.

A retrospective study was performed to determine the appropriateness and efficiency of preoperative blood ordering practices in orthognathic surgery. Results obtained showed that preoperative blood typing and crossmatching should be performed on patients who will be receiving combined maxillary and mandibular osteotomies with iliac crest grafts. Patients receiving all other types of osteotomies should have only preoperative blood typing and screening. This will serve to reduce cost to the patient, blood wastage, and the laboratory work load.

One hundred and eighty-four patients with T0-T2, N0-N1b, M0 breast cancer were treated by local excision and radical radiotherapy. Short-term morbidity and cosmetic assessment are reported after a median follow-up of 21 months. At 1 year 80% of women considered the cosmetic result very good or excellent, whereas only 63% of their consultants gave a similar assessment. Mild or moderate arm oedema developed in 22% of patients, radiation pneumonitis in 9% and oesophagitis in 11%. Mild discomfort in the treated breast was reported by 39% and moderate by 17%. Oedema of the breast was noted in 20%. It is too early to comment on long term disease control or final cosmetic result but to date the morbidity has been considered acceptable and measures to reduce it further are being implemented.

Although acute renal failure is a well recognized complication of several extra-hepatic biliary tract diseases especially biliary tract surgery in the presence of obstructive jaundice, there is little information concerning renal failure in acute cholecystitis. Renal function was assessed in 14 patients with acute cholecystitis and two with acute cholangitis. Six patients had no evidence of renal impairment, four had modest elevations of plasma urea and creatinine concentrations and six had acute reversible renal failure of whom three required peritoneal dialysis. Only one patient was hypovolaemic and in the remainder there was evidence that intravasular coagulation was responsible for the renal failure. It is suggested that bacteraemia was the initiating factor. The therapeutic implications of these findings are discussed.

Eleven patients with measurable subcutaneous or pulmonary metastases were selected for a study of the effectiveness of the radiosensitizer misonidazole (MIS). Evaluable data were obtained in 6 patients and radiosensitization demonstrated in 5. Patients were irradiated either before or after MIS, and each patient acted as his own control. Response to treatment in 5 cases was assessed in terms of growth delay, and radiation doses were selected in expectation of enhancement ratios of 1.2 to 1.5. In 1 case evidence of sensitization was obtained from differential tumour clearance from 2 areas of skin irradiated before or after MIS. Results in 4/5 growth-delay studies indicated enhancement ratios ranging from 1.1 to greater than 1.5. An enhancement ratio of 1.3 was measured in a case of squamous carcinoma treated by a 10-fraction course of irradiation. Evidence of sensitization was obtained in breast carcinoma, osteosarcoma, leiomyosarcoma, prostatic carcinoma and synoviosarcoma. The results of this study support the view that MIS may improve the radiotherapeutic management of a wide range of tumours, although more extensive data are required to identify those categories of disease in which greatest benefit will be obtained, and to indicate the optimum radiation schedule.

Ligands in the first coordination sphere of Mn(II) in the complex of MnADP with myosin subfragment 1 from rabbit skeletal muscle have been investigated. EPR spectroscopy was used to detect superhyperfine coupling between unpaired electrons of the metal ion and the nuclei of oxygen atoms specifically labeled with oxygen 17. The results show that ADP is a beta-monodentate ligand for Mn(II) and that there are probably two water oxygens directly bound to Mn(II). The inhibitory complex of vanadate with subfragment 1 . MnADP was also investigated. Vanadate-dependent changes in the EPR spectra for enzyme-bound Mn(II) indicate that the coordination sphere of MN(II) changes upon binding of vanadate. ADP remains a beta-monodenate ligand in the complex and experiments with 17O-labeled water indicate that two oxygen atoms originally in water are ligands in the complex. However, the oxygens of vanadate equilibrate with those of water during sample preparation so that one of these ligands may be a vanadate oxygen. Three additional ligands, probably from the protein, are required to complete the sextet of ligands to Mn(II) in both complexes studied.

Glutamic acid 1-semialdehyde hydrochloride was synthesized and purified. Its prior structural characterization was extended and confirmed by 1H NMR spectroscopy and chemical analyses. In aqueous solution at pH 1 to 2 glutamic acid 1-semialdehyde exists in a stable hydrated form, but at pH 8.0 it has a half-life of 3 to 4 min. Spontaneous degradation of the material at pH 8.0 generated some undefined condensation products, but coincidentally a significant amount isomerized to 5-aminolevulinate. At pH 6.8 to 7.0, glutamate 1-semialdehyde is sufficiently stable to permit routine and reproducible assay for glutamate 1-semialdehyde aminotransferase activity. Only about 20% of the enzyme extracted from chloroplasts was sensitive to inactivation by gabaculine with no pretreatment. However, when the enzyme was exposed to 5-aminolevulinate, levulinate or 4,5-dioxovalerate in the absence of glutamate 1-semialdehyde, it was completely inactivated by gabaculine; 4,6-dioxoheptanoate had no effect on the enzyme. These results lead to the hypothesis that the aminotransferase exists in the chloroplast in a complex with pyridoxamine phosphate, which must be converted to the pyridoxal form before it can form a stable adduct with gabaculine. We propose that the enzyme catalyzes the conversion of glutamate 1-semialdehyde to 5-aminolevulinate via 4,5-diaminovalerate.

Determined whether individuals who adapted well or poorly to the loss of their vision could be differentiated on the basis of the Cattell 16PF. Well adjusted individuals were defined as those who displayed minimal depression and high social independence, while poorly adjusted individuals were highly depressed and socially dependent. By the use of discriminant analysis based upon the standard 16PF, 84.5% of highly depressed and 81% of the minimally depressed group were classified accurately. In a second analysis, 75% of socially independent and 73% of socially dependent individuals were classified correctly. Premorbid characteristics of well and poorly adjusted blind Ss were described.

Ninety-six patients with inoperable carcinoma of the bronchus were entered into a prospective study of the effectiveness of palliative radiotherapy. The median survival of the group as a whole was 38 weeks. Major symptoms such as cough, dyspnoea and haemoptysis were well controlled at 3 months and 6 months follow-up. There was no significant effect on performance status. Dysphagia and tiredness occurred in 81% of patients, but were classed as mild in 41% and 47% respectively, lasting less than 4 weeks in 86%. There was no correlation between the radiotherapy dose received and symptom control. Fourteen per cent of patients were dead within approximately 3 months of treatment and were unlikely to have benefited from therapy. Careful selection of patients for palliative radiotherapy is recommended.

The question of the stoichiometry of copper bound to dopamine beta-hydroxylase and the number of copper atoms required for maximal activity was addressed in this study. Incubation of tetrameric enzyme from bovine adrenal medulla with 64Cu2+ followed by rapid gel filtration yielded an enzyme containing 8.3-8.9 mol of Cu/mol of tetramer. An identical stoichiometry was obtained by analysis of bound copper by atomic absorption methods. NMR and EPR were used to monitor titrations of the enzyme with Cu2+ and showed that the longitudinal relaxation rate of solvent water protons and the amplitude of the signal at g approximately 2 increased linearly up to a copper to protein ratio of approximately 8. Additional titrations also indicate that an enzyme-Cu2+-tyramine-CN- inhibitory complex was formed when 8 mol of Cu2+ are bound per mol of enzyme. The rate of inactivation of dopamine beta-hydroxylase by the mechanism-based inhibitor 2-Br-3-(p-hydroxyphenyl)-1-propene was measured and used as a method to follow enzymatic catalysis. An increase in rate was observed with increasing Cu2+ up to a protein to Cu2+ ratio of 8 Cu/tetramer. The rate becomes constant after this ratio is achieved. These data indicate that dopamine beta-hydroxylase specifically binds 8 mol of Cu/tetramer and that this stoichiometry is required for maximal activity.

Three incidents are reported, from different radiotherapy centres, in which an implanted iridium-192 wire remained in the tissues of a patient after withdrawal of the plastic tubing in which it was contained. In each case the instrument used to cut the wire had probably formed a hook on the end of the wire which caused it to catch in the tissues. Detailed recommendations are made for avoiding such incidents in the future, the most important of which is that the patient should be effectively monitored after the supposed removal of all radioactive sources.

As a result of almost 20 years' experience using 192Ir wires in interstitial radiation therapy, a new method of dose calculation has been evolved, which is especially suitable for the techniques employed. Because this system was developed and brought into routine use in Paris, it was called the Paris System. Its basic principles are outlined in this report and the manner in which it is used in clinical practise is explained.

We wished to explore the relationship between certain blinding eye diseases, residual vision and psychosocial adjustment, including acceptance of blindness. One hundred and fourteen patients were grouped according to level of vision, age, type of disease, general physical health and duration of blindness. Psychological symptoms were measured by the Minnesota Multiphasic Personality Inventory (M.M.P.I.) and social function by an adaptation to blindness of the Gunzberg Progress Chart of Social Function. Social adjustment was best and psychological morbidity least in those with non-diabetic retinal disorders, those who had the best vision and those who accepted their blindness. Non-acceptance of blindness was associated with the most psychological distress and the lowest scores in social adjustment. People with glaucoma and diabetic retinal disorders seemed more poorly adjusted. An attempt should be made to identify those most prone to maladjustment so as to assist them in rehabilitation.

Six patients with a total of 34 assessible subcutaneous or cutaneous lesions were treated with photodynamic therapy using 1.0, 1.5 or 2.0 mg kg-1 of photofrin II and 25-100 J cm-2 of red light (630 nm). The incidence of complete tumour response and skin necrosis were used to try to assess the therapeutic ratio of photodynamic therapy. The tumour response rate was 47%. The rate of tumour control and necrosis increased in parallel with dose of photosensitizer and light used, implying a low therapeutic ratio. However, the use of necrosis with eschar formation as an end-point for severe normal tissue damage is questioned as the skin healed completely in all cases and with minimal discomfort to the patients.