Mass spectrometric evidence for the anomalous chemical behavior of 11-dehydrothromboxane B2

When we subjected 11-dehydrothromboxane B2 (11-DTXB2), a metabolite of arachidonic acid, to standard chemical derivatization procedures we obtained a mixture of several products. Separation of the components was carried out by gas chromatography and their identification was accomplished through the study of their mass spectra, which are presented here. Anomalous behaviors include methylation of allylic and alcoholic hydroxyl groups by diazomethane, unusually slow derivatization of one of the hydroxyl groups with N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) and etherification of another with ethanol. The underlying causes of these abnormal behaviors are not obvious, but appear to be related, at least in part, to the opening/closure of a lactone ring in the molecule. These observations have some bearing on the development of valid procedures for GC-MS quantification of this important marker of thromboxane A2 synthesis in vivo, and of similar compounds.

Evaluation of respiratory system resistance in mechanically ventilated patients: the role of the endotracheal tube

OBJECTIVE

To investigate the role played by the endotracheal tube (ETT) in the correct evaluation of respiratory system mechanics with the end inflation occlusion method during constant flow controlled mechanical ventilation.

SETTING

General ICU, university of Rome "La Sapienza".

PATIENTS

12 consecutive patients undergoing controlled mechanical ventilation.

METHODS

We compared the values of minimal resistance of the respiratory system (i.e. airway resistance) (RRS min) obtained: i) subtracting the theoretical value of ETT resistance from the difference between P max and P1, measured on airway pressure tracings obtained from the distal end of the ETT; ii) directly measuring airway pressure 2 cm below the ETT, thus automatically excluding ETT resistance from the data. RESULTS. The values of RRS min obtained by measuring airway pressure below the ETT were significantly lower than those obtained by measuring airway pressure at the distal end of the ETT and subtracting the theoretical ETT resistance (4.5 +/- 2.8 versus 2.5 +/- 1.6 cm H2O/l/s, p < 0.01).

CONCLUSION

When precise measurements of ohmic resistances are required in mechanically ventilated patients, the measurements must be obtained from airways pressure data obtained at tracheal level. The "in vivo" positioning of ETT significantly increases the airflow resistance of the ETT.

Assay of urinary 2,3-dinor-6-oxo prostaglandin F1 alpha by gas chromatography-tandem mass spectrometry

Prostacyclin (PGI2), an important determinant of cardiovascular biology, is produced from arachidonic acid by endothelial cells. Measurement of its stable urinary metabolite, 2,3-dinor-6-oxo prostaglandin F1 alpha (PGI2-M), is the approach of choice to assess variations of the endogenous synthesis of PGI2 that occur in response to dietary, pharmacological and pathological alterations. We developed a relatively simple stable isotope dilution assay for PGI2-M which involves solid-phase extraction of 10 ml of urine with Chem Elut disposable columns, water/solvent partitioning from basic and acidic environments with ethyl acetate and methylene chloride, derivatization to 1-pentafluorobenzyl ester followed by TLC, methoximation and trimethylsilylation. Quantification was achieved, for the first time for PGI2-M, by capillary GC-electron capture negative ion MS-MS with a triple quadrupole mass spectrometer operated in the negative ion detection mode with methane as moderating gas. The mean inter-assay R.S.D., determined on 12 different urine samples, was 5.1 (range 0.4% to 10.5%). The excretion of PGI2-M in 34 healthy male subjects (age 26 to 57) was 156.2 +/- 65.2 (mean +/- S.D.) ng/24 h.

Detection of neutral active phosphatidylcholine-specific phospholipase C in Friend leukemia cells before and after erythroid differentiation

With respect to normal tissues, 31P NMR spectra of tumors usually exhibit elevated phosphomonoester (PME) and phosphodiester (PDE) signals, arising from phospholipid metabolites such as phosphocholine (PCho) and glycerophosphocholine (GroPCho) (and/or ethanolamine analogues). PME and PDE resonances may undergo significant alterations during tumor growth, at early stages of tumor response to treatment or following cell differentiation and maturation. The enzymatic mechanisms which regulate these alterations are scarcely understood. Recent studies on agonist-induced phosphatidylcholine (PC) hydrolysis by PC-specific phospholipase C (PC-plc) in cells stimulated by hormones or growth factors suggest the hypothesis that repeated transient activations of this enzyme may also contribute to the elevation of PCho levels in tumor NMR spectra. This paper reports the first direct evidence on neutral active PC-plc activity in a tumour cell system, Friend leukemia cells, either in the undifferentiated (FLC) or differentiated state (dFLC). Cell homogenates were incubated in the presence of mixed diheptanoylphosphatidylcholine/sphingomyelin unilamellar vesicles (SLUV), which were previously shown to represent a good substrate for bacterial plc. 31P NMR analyses allowed the simultaneous detection and quantification of phosphorylated metabolites produced in tumor cell homogenates by PC-plc activity, as well by enzymes active in the PC deacylation pathway. With respect to FLC, dFLC homogenates exhibited higher PC-plc activity and lower accumulation of a deacylation product, GroPCho, in agreement with the elevation in the [PCho]/[GroPCho] ratio, already reported in 31P NMR spectra of intact differentiated cells. The direct detection of PC-plc in this cell system opens novel biochemical interpretations on a series of oncological observations, such as a) transient increases in the levels of PCho and PC-derived diacylglycerols reported in immature or in transformed cells in response to agonist-receptor interactions and b) accumulation of mobile lipids in tumor cell membranes and tissues.

Pentose phosphate pathway alterations in multi-drug resistant leukemic T-cells: 31P NMR and enzymatic studies

31P NMR studies were carried out on the parental drug-sensitive human T-lymphoblastoid cell line CCRI-CEM (CEM) and its multi-drug-resistant (MDR) CEM-VBL100 variants, to assess the role of the pentose phosphate (PP) in MDR expression. CEM and CEM-VBL100 were incubated in the presence of 2-deoxyglucose, as recently proposed by our group (Clin. Chim. Acta 208: 39, 1992). Accumulation of 2-deoxyglucose 6-phosphate was much lower in the drug-resistant than in sensitive cells, indicating PP shunt activation in the MDR variants. This result was confirmed by enzymatic analyses, which demonstrated that, with respect to the parental line, the MDR variant was characterized by a) unaltered hexokinase activity; b) higher glucose 6-phosphate dehydrogenase activity; c) increased levels of reduced glutathione and marked increase of glutathione peroxidase activity after cell exposure to an oxidizing agent (tert-butylhydroperoxide). These results support the view that cell detoxification mechanisms mediated by the pentose phosphate pathway may contribute to the expression of MDR in tumours.

Ingestion of marine oil reduces excretion of 11-dehydrothromboxane B2, an index of intravascular production of thromboxane A2

We evaluated the effect of anchovy oil supplementation on the endogenous production of thromboxane A2 by measuring the excretion of its stable metabolite, 11-dehydrothromboxane B2 (11-DTXB2), in 24-h urine. In a longitudinal study, 35 male volunteers consumed a controlled basal diet for two experimental periods lasting a total of 20 weeks. During period 1 (10 weeks) the diet was supplemented with placebo (PO) capsules (15 x 1 g/d) consisting of a blend of fats approaching the fatty acid profile of the basal diet. During period 2 the subjects received 15 x 1 g/d capsules of fish oil concentrate (FOC). PO and FOC capsules contained 1 mg alpha-tocopherol per gram of fat as antioxidant. A 38% reduction of 11-DTXB2 excretion was observed after 10 weeks of FOC supplementation (period 2, n-6/n-3 PUFA ratio = 2.3), compared to an identical period of PO supplementation (period 1, n-6/n-3 = 12.5), p = 0.0001. The 11-DTXB2 excretion reduction (delta) fits the quadratic equation delta = 136.0038-0.3178(tx1)-0.0002(tx1)2, (R2 = 0.8944), where tx1 is the excretion rate at the end of period 1. This finding supports the hypothesis that the antithrombotic effect of marine oil is mediated, at least in part, by diet-induced shifts in the eicosanoid system.

Arthroscopic treatment of flexion deformity after ACL reconstruction

After anterior cruciate ligament (ACL) reconstruction, one frequent complication is the restriction of the range of motion and loss of extension. In addition to the presence of adhesions in the suprapatellar pouch, it is possible to detect two different pathological findings in the intercondylar notch: a misplacement of graft causing an intercondylar impingement, or the presence of hypertrophic tissue originating from the graft that blocks the last degrees of extension, causing an "anterior impingement." We reviewed 18 consecutive cases treated by arthroscopic release. All patients had knee range-of-motion restriction after an ACL procedure. The follow-up at 1 and at 6 months shows that good results have been obtained in cases of anterior impingement, whereas in cases of intercondylar impingement a restricted range of motion, especially of flexion, did remain. In all cases, after arthroscopic treatment the postoperative extension was between 5 and 10 degrees, but this deficit regressed after 6 months in 12 patients, whereas a dropout case was necessary in the remaining 6 patients.

GC/MS/MS quantification of 11-dehydrothromboxane B2 in human urine

A fully validated stable isotope dilution method for rapid quantification of 11-dehydrothromboxane B2 by gas chromatography/negative chemical ionization tandem mass spectrometry is reported. The interassay coefficient of variation was 1.3%. The relative recovery of synthetic, underivatized 11-dehydrothromboxane B2 added to urine was 84.6 +/- 2.5% (mean +/- SEM, N = 9). The equation of the regression plot correlating the amounts added and recovered was Y = 0.894X-0.23, with R = 0.9963. The late introduction of the pentafluorobenzyl moiety at C11 afforded distinct advantages in the cleanup stage of the assay and during the GC/MS analysis as well. The pair of daughter fragments at m/z 345 and 349 of the parent fragment ions at m/z 615 and 619 were monitored. Excretion values of 11-dehydrothromboxane B2 in 3 healthy male subjects were 975, 615 and 822 ng/24 h. Excretion was reduced to 751, 387 and 465 ng/24 h, respectively, after administration of a fish oil supplement (15 g/day) for 10 weeks.

13C and 31P NMR studies of glucose and 2-deoxyglucose metabolism in normal and enzyme-deficient human erythrocytes

The flux of 13C-labeled glucose through the Embden-Meyerhof and pentose phosphate pathways was studied by 13C NMR in intact erythrocytes isolated from normal subjects or from patients suffering of glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) deficiency. Similar rates of glucose catabolism and similar fluxes of the 13C-label into 2,3-bisphosphoglycerate and lactate were found, under basal conditions, in normal and in G6PD-deficient erythrocytes incubated in the presence of either [1-13C]- or D[6-13C]glucose. Exposure to oxidative stress by preincubation with tert-butylhydroperoxide induced in normal, but not in G6PD-deficient erythrocytes, a significant enhancement of glucose consumption, as well as a substantial reduction in 13C-label transfer from C1-glucose into lactate. It was also possible, by 31P NMR, to evaluate the conversion of 2-deoxyglucose to its phosphate-containing metabolites. The oxidation and subsequent decarboxylation of 2-deoxyglucose-6-phosphate was assessed in reconstituted systems and could subsequently be evidenced also in ethanolic extracts from normal (but not from G6PD-deficient) erythrocytes which had been exposed to oxidative stress. The results indicate that, in terms of glucose flux through the glycolytic pathway, there is little or no difference between normal and G6PD-deficient erythrocytes, regardless of previous exposure to oxidative stress. Faster consumption of either glucose or 2-deoxyglucose is induced, only in normal cells, by treatment with tert-butylhydroperoxide, essentially as a consequence of the activation of the pentose-phosphate pathway.

Knee ligament injuries in volleyball players

The authors report a series of 52 cases of serious knee ligament injuries in volleyball players. The most frequent mechanism of injury was landing from a jump in the attack zone. Women were more affected than men. Injuries were more frequent during games than training. Volleyball must then be considered among high-risk sports according to the frequency and gravity of our surgical findings. Results are similar to those obtained in athletes in other sports who underwent the same surgical procedure.

Osteoarthritis of the knee after ACL reconstruction

One hundred and fourteen knees with deficiency of the anterior cruciate ligament (ACL) which had undergone reconstruction of the ligament using semitendinosus and gracilis were reviewed at a mean of 61 months after operation. Radiological and clinical evaluation was undertaken. A significant correlation was found between the number of meniscectomies performed in acute cases and those undertaken on the chronic knee. There was also significant correlation between meniscectomy and the Fairbank grading of degenerative changes seen on the radiographs. There was no correlation between the clinical results, residual laxity and the development of osteoarthritis. In ACL deficient knees with irreparable meniscal tears, or in which meniscectomy had been undertaken, the development of osteoarthritis seemed independent of the degree of stability, but in such knees with no meniscal tear or meniscal repair, reconstruction appeared to save the menisci and preserve the joint.

PGE1 compared to PGE2/PGF2 alpha ratio as a marker for seminal fluid contamination of urine in studies of renal prostaglandin biosynthesis

Occasional and unpredictable seminal plasma leakage (SPL) into the urinary system severely limits the usefulness of primary prostaglandin (PG) excretion rates as markers of renal synthesis in male subjects. Although reports to this effect appeared first some 10 years ago, no specific study has been done to define the magnitude of the problem, while several investigators persisted in the use of primary PG excretion rates, disregarding SPL as a confounding factor. We conducted a systematic study with a group of 5 healthy adult subjects who collected 24-h urine with an average frequency of one collection every other week for a total of 20 weeks. 35% of the urine collected contained seminal plasma. It is imperative to be able to disqualify compromised urine specimens in biological studies. With this objective in mind, we developed a method to identify contaminated samples based on the presence of PGE1. This is a major prostanoid in seminal plasma but is normally absent in 'clear' urine.

Effect of fish oil supplementation on the excretion of the major metabolite of prostaglandin E in healthy male subjects

We investigated the effect of fish oil supplementation on the synthesis of prostaglandin E (PGE) in vivo by measuring the excretion of its catabolite, PGE-M, in 24-hr urine by gas chromatography/mass spectrometry. Forty healthy male volunteers (24-57 years of age) consumed a controlled basal diet providing 40% of energy from fat (P/S ratio about 0.8:1), 130 mg/1000 kcal cholesterol, and a minimum of 22 mg/day of alpha-tocopherol (alpha-T), for three experimental periods lasting a total of 28 weeks. During period 1 (10 weeks) the diet was supplemented with placebo (PO) capsules (15 X 1 g/day) consisting of a blend of fats approaching the fatty acid profile of the basal diet. This was followed by a second 10-week period during which the subjects received 15 X 1 g/day capsules of fish oil concentrate (FOC). During period 3 (8 weeks) they continued the 15 g/day intake of FOC but received an additional 200 mg/day of alpha-T. PO and FOC capsules contained 1 mg alpha-T/g fat as antioxidant. A 14% reduction of PGE-M excretion was observed after 10 weeks of FOC supplementation (period 2), compared to an identical period of placebo supplementation (period 1), P = 0.009. PGE-M excretion during the last week of period 3 was not significantly different from that at the end of period 2. The reduction in PGE synthesis in response to the relatively high marine oil supplementation was large in many subjects participating in this study.

Third-degree lesions of the external compartment of the ankle: results of conservative treatment

Ankle sprains are one of the most common lesions of the musculo-skeletal system. In some sports they are the most common reason that athletes seek medical care. For this reason many publications are dedicated to this subject, and specifically to the treatment of lesions of the external compartment, which account for about 85% of all ligamentous lesions of the ankle (O'Donoghue, 1958). The treatment of these lesions is very controversial. Some orthopedists propose early surgical treatment to restore normal healing with minimal functional lengthening. Others favor conservative treatment, while still others recommend functional treatment with the objective of accelerating the recovery of proprioceptive reflexes affected by the ligamentous lesion as well as stimulating healing by movement. The authors' diagnostic and therapeutic approach to lesions of the external compartment of the ankle is explained with special reference to lesions in athletes, who must be guaranteed perfect joint stability in order to tolerate the intense stress of sports activity without danger of relapse.

Chondromalacia and chronic anterior instabilities of the knee

In this study, we surveyed a consecutive series of 500 patients who had undergone an open procedure for chronic anteromedial and/or anterolateral instabilities. Those patients who had an open arthrotomy were separated for analysis. All of the patients were examined before and during surgery. A knee sheet, based on the kind used at the Hughston Orthopaedic Clinic in Columbus, Georgia, was used to record all clinical findings. Chondromalacia of the articular surface of the femur was detected at surgery in 161 patients (32%). A statistical analysis showed that the variables directly influencing degenerative changes of the cartilage are: a previous surgery that did not sufficiently restore joint kinematics (chi square = 20.238, P less than 0.001) and a time lapse of more than 30 months between first trauma and surgery (chi square = 21.736; P = 0.001). A higher score on dynamic (jerk or pivot shift) and static (internal and external anterior drawer) tests, indicating instability, or a meniscal tear alone do not statistically correlate with chondromalacia, but together they influence degenerative changes of the cartilage.

Results of reconstruction of the anterior cruciate ligament with the tendons of semitendinosus and gracilis in acute capsulo-ligamentous lesions of the knee

This report presents the mid-term results of 55 cases of anterior cruciate ligament (ACL) lesions surgically treated in "acute phase" using intra-articular transfer of the semitendinosus and gracilis tendons, performed at the First Orthopedic Clinic of "La Sapienza" University in Rome since 1979. The follow-up is based on clinical (point system comprising subjective and objective criteria), instrumental (KT-1000 arthrometer), and radiographic (comparative AP view radiographic exam of the knees under load) data. On the basis of the results obtained, ACL reconstruction with the semitendinosus and gracilis tendons in the treatment of acute lesions can provide the patient with a good possibility of complete functional recovery of the knee.

Modification of prostaglandin metabolism in vivo by long-chain omega-3 polyunsaturates

In a pilot study conducted with a healthy male volunteer we determined that short-term dietary supplementation with fish oil markedly suppresses the systemic production of prostaglandin E (P = 0.04). This biochemical effect is observable after an incubation period of several days. The potential consequences of a reduced PGE synthetic rate on renal function, immune system and vascular dynamics, must be considered in the overall evaluation of the safety of fish oil supplements.

Knee injuries in volleyball

The knee is the most frequent site of injury in volleyball players. More than 40% of high level players suffer overuse injuries during this activity; this particularly painful syndrome is caused by the amount of jumping typical in volleyball play, and in its training which aims at strengthening the quadriceps muscle. In volleyball players the extensor apparatus is subject to continuously high stress and the bone tendon junction, being the weakest point, is susceptible to lesion. The prevention and treatment of 'jumper's knee' requires a high degree of cooperation among trainers, doctors and athletes. Although volleyball is a sport without contact between players, traumatic acute injuries are more frequent and more serious than would be expected. It is therefore important to emphasise that volleyball must be considered among the high risk sports that expose the knee not only to twisting, but also to contact with other players. Generally, the lesions are caused by frequent jumps with loss of balance and a consequent 'one-footed' landing. There is no specific method of preventing knee instability. Accurate diagnoses, rest and rapid surgical treatment after the first injury are recommended in order to avoid chronic knee instability with subsequent meniscal lesions and post-traumatic osteoarthritis.

The results of reconstruction of the anterior cruciate ligament with semitendinosus and gracilis tendons in chronic laxity of the knee

The authors report the medium term results (41 months) in 88 patients submitted to surgery for reconstruction of the anterior cruciate ligament according to the method currently in use at our Clinic which uses the semitendinosus and gracilis tendons. The results were evaluated according to a score card method and in 28 patients a KT-1000 arthrometer was also used. The method gives a probability of full success in approximately 85% of cases, with significantly better results in patients not submitted to meniscectomy. A comparison with other methods of autogenous transplant and prosthetic substitution, even on the basis of the data provided by the KT-1000, still places the semitendinosus and gracilis method at the forefront.

Interleukin-1 beta induces tumor necrosis and early morphologic and metabolic changes in transplantable mouse tumors. Similarities with the anti-tumor effects of tumor necrosis factor alpha or beta

Peri-tumoral injection of recombinant human interleukin-1 beta in mice transplanted s.c. with Friend erythroleukemia cells (FLC) resulted in marked inhibition of tumor growth and increased survival. However, in vitro treatment of FLC (745 or 3Cl-8) with IL-1 beta barely inhibited cell multiplication. IL-1 beta, injected into established solid tumors, induced marked morphologic changes. Vascular congestion and focal extravasation of erythrocytes were observed as early as 6 hr after injection with IL-1 beta of FLC and L1210 tumors and HeJ16 fibrosarcomas. Focal areas of disaggregation of tumor cells and tumor necrosis were observed 6 and 24 hr after IL-1 injection. These morphologic changes were similar to those observed in FLC tumors or HeJ16 fibrosarcomas treated with TNF-alpha or beta. These cytokines determined morphological changes in tumor blood vessels of FLC tumors within 1 hr of injection. Freshly dissected FLC tumors and their tissue extracts were studied by Nuclear Magnetic Resonance (NMR) spectroscopy, shortly after peri-tumoral injection of IL-1 beta or TNF-beta. After 6 hr, both cytokines induced a 3-fold reduction in the levels of two catabolites, glycerophosphorylcholine and glycerophosphorylethanolamine, an accumulation of sn-glycerol 3-phosphate and a more than 10-fold increase in the choline/phosphorylcholine ratio. These results are similar to those reported for TNF-alpha, and can be interpreted on the basis of an activation of glycerophosphorylcholine phosphodiesterase (EC 3.1.4.2) and partial inhibition of choline kinase (EC 2.7.1.32). IL-1 beta and TNF-beta (like TNF-alpha) also induced alkaline shifts (0.10-0.25 units) in the average intratumoral pH value. We suggest that alterations of tumor blood vessels may be the primary events in solid tumors treated with IL-1 beta or TNF. Such alterations lead to early changes in tumor metabolism and subsequent tumor cell degeneration.

Modulating influence of dietary lipid intake on the prostaglandin system in adult men

We evaluated the effect of moderate dietary changes on the prostaglandin system by measuring the urinary excretion of 7 alpha-hydroxy-5,11-dioxo-tetranorprostane-1,16-dioic acid (PGE-M). In a crossover design, twenty-four free-living male subjects in good health (24 to 54 years of age) were fed two diets: (i) Regular (R) diet, 41% energy (en%) from fat, P/S 0.59, M/S 0.96; (ii) Experimental (E) diet, 19 en% from fat, P/S 1.31, M/S 1.48. Diet R contained 13.9 g/day of neutral detergent fiber (NDF) and about 600 mg/day of cholesterol per 3200 kcal; Diet E contained 35.5 g/day NDF and about 280 mg/day cholesterol. Each controlled-diet period lasted ten weeks. The menu cycle was 7 days, and all diets were calculated to provide adequate amounts of essential nutrients. The PGE-M excretion rates were determined in 24-hr urine by stable-isotope dilution gas chromatography-mass spectrometry in the selected ion-monitoring mode. Low-fat Diet E, with an intake of 6.6 en% from polyunsaturates, was associated with an average 14.2% reduction in PGE-M daily output, compared to high-fat Diet R with a 9.3 en% from polyunsaturates (P = 0.046). These results support the view that dietary lipid changes can significantly alter the in vivo production of E-series prostaglandins. We cannot conclude, however, if this apparent diet effect was brought about by the change in linoleate intake alone or was the result of complex biochemical interactions among individual fatty acids, both saturated and unsaturated.

Arthroscopic arthrolysis of the knee

The authors report their experience in the arthroscopic treatment of joint-related stiffness of the knee. Arthroscopic arthrolysis is the treatment of choice for numerous conditions (stiffness subsequent to inflammatory processes, stiffness associated with marked osteoporosis, etc.) in which open arthrolysis is contraindicated. The totally atraumatic nature of arthroscopy and the more accurate lysis of the adhesions allow for postoperative management without complications or pain. This is of particular importance as it permits passive and active kinesitherapy from the moment the patient recovers from anaesthesia, without pain and therefore with greater commitment on his part. Furthermore, arthroscopic arthrolysis can be used successfully to treat extensor muscle stiffness where endoscopic study has revealed the presence of adhesions or calcification in the anterior compartments.

Reconstruction of the anterior cruciate ligament by semitendinosus transfer in chronic anterior instability of the knee

Between 1979 and 1983, 127 chronic anteromedial or anterolateral instabilities of the knee were submitted to surgical treatment (Hughston et al., 1976; Imbert, 1984). The central pivot was reconstructed by the semitendinosus tendon, using our own modification of the original Hughston technique (Puddu et al., 1986). On the medial side we advanced the posterior oblique ligament and reflex tendon of semimembranosus in cases submitted to medial meniscectomy at the same time. Laterally, we always advanced the biceps. As this method produced excellent results very quickly, it was later improved by associating the gracilis tendon with the semitendinosus. Assessment of the results was based on an average follow-up of 5 years (minimum 4, maximum 7). Of the 127 patients we personally interviewed 108 and clinically evaluated 88 professional sportsmen. The results in the latter group were excellent or good in 76.

Occurrence of prostaglandin E3 in human urine as a result of marine oil ingestion: gas chromatographic-mass spectrometric evidence

This pilot study is an effort to elucidate the metabolic fate of dietary eicosapentaenoate in vivo and its influence on arachidonate cyclooxygenation at the renal level. The ultimate objective is to shed light on the biochemical mechanisms responsible for the physiologic effects of marine oil on humans. We found prostaglandin E3 (PGE3) in urine of a female volunteer who ingested 10-50 g/day of MaxEPA fish oil concentrate for 4 years. PGE3, a cyclooxygenase metabolite of eicosapentaenoate, could not be detected in 24-h urine pools from the same subject 16 weeks after fish oil supplementation ended. The appearance of PGE3 was concurrent with a reduction of urinary PGE2. Identification of the trienoic prostaglandin was based on comparison of chromatographic behavior of three distinct derivatives of endogenous PGE3 with that of authentic material, and on selected ion monitoring mass spectrometry.

Prognostic value of brainstem auditory evoked potentials in pediatric patients with traumatic coma

This paper studies the auditory evoked potentials of the brainstem (BAEPs) in 30 pediatric patients with serious head trauma admitted to a particular hospital. The results have shown the importance of BAEPs especially in those patients whose prognoses are uncertain.

Evaluation of the results of extensor mechanism reconstruction

One hundred sixteen patients underwent extensor mechanism reconstruction. Ninety-four returned at followup (3 to 11 years after surgery). Twenty-two patients were lost to followup. Subjectively, 74% of the patients had either an excellent or good result and 26% either a fair or poor result. We found retrospectively, that the patients with either fair or poor results had a stable or only mildly unstable patella preoperatively.

Stable isotope dilution assay for prostaglandin E metabolite: 24-hour urinary output in healthy male subjects

A stable isotope dilution assay for the major urinary metabolite of prostaglandins E1 and E2 (PGE-M) was developed. After extraction and purification, the compound was converted to the dimethyl ester bis(O-methyloxime)-trimethylsilyl ether derivative and quantified with the 13C-labeled dimethyl ester analog as internal standard. The interassay coefficient of variation was 0.8%, and the intraassay coefficient of variation ranged from 0.9 to 1.7%. The recovery of authentic, underivatized PGE-M added to urine was 99.5 +/- 3.2% (mean +/- SE, N = 9). The equation of the regression curve correlating the amounts added and recovered was Y = 1.05X - 5.84, with R = 0.998. The level of excreted metabolite in healthy male subjects was 13.86 +/- 1.46 micrograms/24 h (N = 24), in good agreement with data from other sources.

Suprascapular neuropathy in volleyball players

We examined ninety-six top-level volleyball players from eight teams that competed during the 1985 European Championships, and twelve players were found to have asymptomatic isolated paralysis of the infraspinatus of the dominant side. Three players were studied with electromyography and Cybex-II isokinetic dynamometry. The results revealed denervation of the infraspinatus and approximately a 22 per cent loss of strength of the affected arm during external rotation. These findings were attributed to repeated stress due to stretching of the nerve during cocking of the arm and follow-through when the athlete was serving.

Isokinetic evaluation of the knee after arthroscopic meniscectomy: comparison between anterolateral and central approaches

Twenty patients had undergone arthroscopic meniscectomy for medial bucket-handle meniscal tears. Half had undergone meniscectomy with central approach, and half had been treated by anterolateral technique. Isokinetic evaluation, with a Cybex II isokinetic dynamometer, was done preoperatively and at 14 and 28 days postoperatively. Two weeks after operation, there was only a slight and insignificant decrease of quadriceps function with the central approach as compared with the anterolateral. However, at 4 weeks, no differences were shown between the two portals. The flexor muscles generally recovered more rapidly with the central technique.

Nephropathy associated with Wilms' tumor. A case of a 13-year-old girl

The association of nephropathy with Wilms' tumor and male pseudohermaphroditism is known as Drash's syndrome. The absence of either pseudohermaphroditism or Wilms' tumor has also been reported. The nephropathy, characterized by proteinuria or nephrotic syndrome, leads rapidly and inevitably to renal failure. The renal findings are those of a chronic glomerulopathy with mesangial hypercellularity, glomerular sclerosis, interstitial infiltration and marked tubular dilation. This infrequent syndrome usually appears in early life, between 1 and 3 years of age. The case of nephropathy associated with Wilms' tumor we present here is characterized by age and onset: an abrupt onset of renal insufficiency without previous signs of nephropathy in a 13-year-old girl.

Long-term assessment of negative arthroscopies

A study of 75 patients was performed to assess the accuracy of arthroscopy carried out for clinical diagnosis of meniscal tear. In these patients, arthroscopy did not detect any intraarticular pathology that could explain the preoperative symptoms. Of the 75 patients, seven were subsequently reoperated on, but in 68 the typical symptoms of meniscal tear improved after the diagnostic arthroscopy.

Mass spectrometric evidence for the conversion of exogenous adrenate to dihomo-prostaglandins by seminal vesicle cyclo-oxygenase. A comparative study of two animal species

We present conclusive mass spectrometric evidence for the synthesis of 1a,1b-dihomoprostaglandin E2 and 1a,1b-dihomoprostaglandin F2 alpha by sheep seminal vesicle microsomes and swine whole vesicular homogenates. Swine microsomes prepared according to standard procedure were catalytically inactive, possibly due to autoinactivation of the cyclo-oxygenase caused by metabolism of endogenous substrate released during the isolation procedure. Cyclo-oxygenase activity could be demonstrated, however, when the porcine vesicles were homogenized in the presence of exogenous substrate. Chemical and mass spectrometric evidence presented here allow unequivocal structural assignments.

Epidemiology of jumper's knee

Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

Chronic anterior laxity of the knee: classification and coding of the results of surgical treatment

Between April 1976 and December 1983 we treated 578 cases of anterior capsuloligamentous laxity of the knee surgically (148 acute and 430 chronic). The chronic cases were treated by a variety of techniques; peripheral plastic repair (191 cases), reconstruction of the anterior cruciate ligament with semitendinosus (127 cases), and with semintendinosus and gracilis (112 cases). To achieve uniformity of classification in such a large number of cases it was necessary to simplify and consolidate the data relative to history, objective examination, operative findings and criteria of evaluation of the results. A personal computer was used to provide rapid processing.

Moderate changes in linoleate intake do not influence the systemic production of E prostaglandins

A pilot study was undertaken to determine if moderate changes in linoleate (18:2 omega 6) intake would modulate the prostaglandin E turnover concurrently with, or independently of, changes in the plasma prostaglandin (PG) precursor levels. Four adult male volunteers in good health were fed two controlled diets containing 35% of energy from fat, with either 10 (diet L) or 30 g (diet H) linoleate/day, 30 to 50 g saturated fatty acids/day, and the balance mainly monounsaturated fatty acids. All four subjects were consuming sufficient amounts of polyunsaturates before the study. Protein (13-14%) and carbohydrate (51-53%) contribution to total caloric intake was kept constant. The menu cycle was 7 days, and all diets were calculated to provide adequate amounts of nutrients known to be required by man when data were available. Plasma fatty acids were determined by gas-liquid chromatography, and the turnover of E prostaglandins was assessed by measuring the urinary output of the major metabolite of PGE1 + PGE2 (PGE-M). Whereas we found a clear correlation between 18:2 omega 6 intake and 18:2 omega 6 concentrations in the neutral lipid (P = 0.007) and phosphoglyceride (P = 0.012) fractions of plasma, arachidonate (20:4 omega 6) concentrations in those same plasma fractions did not respond significantly to changes in linoleate intake. Moreover, we could not detect an influence of moderate changes in dietary levels of 18:2 omega 6 on the systemic production of PGE as measured by the daily urinary output of PGE-M.