Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings

AIM

To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury.

MATERIALS AND METHODS

Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard.

RESULTS

The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%.

CONCLUSION

This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.

The evolution of trauma services at Beaumont Hospital

OBJECTIVE

To review and examine the epidemiology, severity and management of trauma admissions at the national neurosurgical teaching hospital.

METHODS

An extensive audit of volume, type and severity of injury and the management requirements of the trauma population admitted to the hospital.

RESULTS

The vast majority of severely injured patients were referred from outside the catchment area of the hospital with only 26% being admitted directly through the Emergency Department. As a consequence, 73% of patients arrived out of normal working hours, which posed problems in providing skilled trauma specialists.

CONCLUSIONS

The management of patients with serious injury is complex. The large proportion of patients with critical injuries, some of whom were paediatric, highlighted the need for 24 h cover by senior trauma personnel and the provision of radiology and operating facilities to meet their needs. The inclusion of indicators of alterations in innate or adaptive immune responses may improve the predictive power of severity of injury scores.

Weekly lometrexol with daily oral folic acid is appropriate for phase II evaluation

PURPOSE

Lometrexol [(6R)-5,10-dideaza-5,6,7,8-tetrahydrofolate] is the prototype folate antimetabolite that targets the de novo purine synthesis pathway. Early phase I trials were confounded by cumulative myelosuppression that prevented repetitive administration. Subsequent preclinical and clinical studies suggested that coadministration of folic acid might favorably modulate lometrexol toxicity without eliminating potential antitumor activity. We set out to determine if concurrent folic acid would allow administration of lometrexol on a weekly schedule, and, if so, to identify an appropriate dose combination for phase II trials. Pharmacokinetic and metabolism studies were undertaken in an attempt to improve our understanding of lometrexol pharmacodynamics.

METHODS

Patients with advanced cancer received daily oral folic acid beginning 7 days before lometrexol and continuing for 7 days beyond the last lometrexol dose. Lometrexol was administered by short i.v. infusion weekly for 8 weeks. Scheduled lometrexol doses were omitted for toxicity of more than grade 2 present on the day of treatment, and dose-limiting toxicity was prospectively defined in terms of frequency of dose omission as well as the occurrence of severe toxic events. Plasma and whole blood total lometrexol contents (lometrexol plus lometrexol polyglutamates) were measured in samples taken just prior to each lometrexol dose.

RESULTS

A total of 18 patients were treated at five lometrexol dose levels. The maximum tolerated dose was identified by frequent dose omission due to thrombocytopenia and mucositis. The recommended phase II dose combination is lometrexol 10.4 mg/m(2) per week i.v. with folic acid 3 mg/m(2) per day orally. One patient with melanoma experienced a partial response, and three patients, two with melanoma and one with renal cell carcinoma, experienced stable disease. Lometrexol was not detectable in any predose plasma sample tested. The total red blood cell content of lometrexol increased over several weeks and then appeared to plateau.

CONCLUSIONS

Weekly administration of lometrexol is feasible and well-tolerated when coadministered with daily oral folic acid. The nature of the interaction between natural folates and lometrexol that renders this schedule feasible remains unclear. A definition of dose-limiting toxicity that incorporated attention to dose omissions allowed efficient identification of a recommended phase II dose that reflects the maximum feasible dose intensity for a weekly schedule. Lometrexol is a promising, anticancer agent.

The effects of telomerase inhibitors on lymphocyte function

BACKGROUND

Telomerase is an enzyme that is present in both cancerous cells and lymphocytes. Telomerase inhibitors block tumor cell growth and are being considered for chemotherapy. This study tested whether telomerase inhibitors suppress growth of leukemic cell lines and blood lymphocytes (PBMC).

RESULTS

Reverse transcriptase inhibitors azidothymidine (AZT) and 3'-deoxy-2:3'-didehydrothymidine (d4T) decreased growth of all cells while dideoxyinosine (ddI) had no effect on Jurkat cells but increased growth of PBMC. The oligonucleotide (TTAGGG)3, which mimics the telomeric sequence, decreased growth of all cells. Inhibition by AZT, d4T and (TTAGGG)3 was manifested at 48-96 hours after addition to the cultures but not at 24 hours. The inhibition was partially to totally reversible upon inhibitor removal, indicating that the compounds were not cytotoxic but only suppressed cell growth temporarily.

CONCLUSIONS

Immunosuppression may result from the use of telomerase inhibitors during chemotherapy but should only be temporary.

Intra-articular tenoxicam improves postoperative analgesia in knee arthroscopy

PURPOSE

Non Steroidal Anti-inflammatory drugs have a well documented benefit in the relief of postoperative pain. This study was designed to compare the analgesic effect of intra-articular tenoxicam 20 mg with intravenous tenoxicam on postoperative pain in 88 patients undergoing day case knee arthroscopy.

METHODS

A prospective, double blind, randomized trial was performed. All patients received a standard general anesthetic. Patients in group A received 20 mg tenoxicam made up to 40 ml with normal saline intra-articularly (ia) and 2 ml normal saline i.v. Patients in group B received 40 ml normal saline intra-articularly and 2 ml, 20 mg of tenoxicam, i.v.

RESULTS

Both groups of patients were similar with respect to age, weight, sex and tourniquet inflation time. Patients receiving ia tenoxicam had lower pain scores (at rest and upon movement) at 30, 60, 120 and 180 min postoperatively (0.8+/-0.2 vs. 2.5+/-0.2 at rest and 1.24+/-0.2 vs. 3.4+/-0.2 at movement at 60 min; P< 0.0001). Fewer patients required additional analgesia in the first four hours postoperatively (33% vs. 84%; P<0.00001) and the time to first analgesia (23.7+/-11.2 vs. 9.4+/-0.6; P<0.02) was longer in those receiving ia tenoxicam.

CONCLUSION

Intra-articular tenoxicam provides superior postoperative analgesia and reduces postoperative analgesic requirements compared with i.v. tenoxicam in patients undergoing day case knee arthroscopy.

Chromosomes of villadia and altamiranoa (crassulaceae)

Villadia, ranging from Texas to Peru with some 25 species, has a rather distinctive thyrsoid to spicate inflorescence, and we keep it as a genus separate from Sedum. Twenty species show every gametic chromosome number from 9 to 17 and also 20-22 and higher. Chromosome pairing in hybrids shows that the species differ by many translocations and that species with 21 or lower are effectively diploid. More specialized species tend to have fewer and larger chromosomes, suggesting that through time translocations have rearranged the ancestral genome into fewer units. We suspect that relocated genes may be programmed differently, affecting phenotype. Thus Villadia is like Echeveria in having a remarkably long descending series of evidently diploid chromosome numbers. Altamiranoa, often included in Villadia, with about 15 species from Mexico south, more closely resembles Sedum in its broadly cymose inflorescence. It appears polyphyletic, with no clear boundary from Sedum, and we disperse its species in Sedum. The ten species studied have gametic numbers from 20 to 29 that probably are effectively diploid, with a few higher and probably polyploid. Again, chromosome pairing in hybrids shows that the species differ by many translocations. Putative relatives in Sedum section Leptosedum have n = 26 to 31. Thus cytologically as well as morphologically Altamiranoa has remained more similar than Villadia to its Sedum relatives.

Evaluation and treatment of childhood obesity

The prevalence of childhood obesity in the United States has risen dramatically in the past several decades. Although 25 to 30 percent of children are affected, this condition is underdiagnosed and undertreated. Hormonal and genetic factors are rarely the cause of childhood obesity; unnecessary diagnostic evaluations can be avoided with a careful history and physical examination. Because obese children may suffer life-long physical and emotional consequences, it is imperative to discuss prevention with parents during well-child examinations. All obese children should be screened for cardiac risk factors, as well as for possible orthopedic, dermatologic and psychiatric sequelae. Treatment should be initiated when the trend in increasing weight obviously surpasses the trend in increasing height. Treatment plans should include reasonable weight-loss goals, dietary and physical activity management, behavior modification and family involvement, which may include weight loss in the parents. Anorexiant medications are not approved by the U.S. Food and Drug Administration for use in pediatric populations.

Better continence care through use of research in clinical practice

A two-year project in Wigan to introduce evidence-based practice in continence care resulted in a better service and falling costs. The strategy involved changing management, introducing audit and assessment procedures, training and establishing a continence advisory service.

Congenital dislocation of the patella in Rubinstein Taybi syndrome

Two patients with Rubinstein Taybi Syndrome (RTS) were found to have congenital dislocation of the patella (CDP). The dislocation was bilateral in one patient. Both underwent surgical reduction and stabilisation. The dislocation recurred in one patient who had associated genu valgum and external tibial torsion at the time of stabilisation. We feel that early diagnosis of CDP in patients with RTS is important to help early mobilisation and avoid secondary degenerative knee changes occurring.

Developmental stages of cucumber seedlings: kinetics of chlorophyll accumulation and other growth parameters

The changes in morphology during dark germination and subsequent growth of cucumber (Cucumis sativus) seedlings in the light go through three different phases described as latent, active, and steady-state. This pattern is consistently observed for several related developmental processes. The latent period lasts about 2 days following water imbibition after which the following capabilities appear in concert: (a) root and stem elongation, (b) pigment synthesis including protochlorophyll, chlorophyll, carotenoid, and phytochrome, (c) synthesis of ribulose-1,5-bisphosphate carboxylase/oxygenase, and (d) enhancement of greening by excision. Following the active phase, which lasts for another 2 to 3 days, these processes slow to a steady-state. Inhibition of chlorphyll accumulation by SO(2) was only observed for seedlings in the steady-state phase.

Rotatory atlantoaxial subluxation following pharyngoplasty

Atlantoaxial rotatory subluxation often presents in childhood as a stiff, painful neck with associated torticollis. It can occur spontaneously following minor trauma or an inflammatory process in the cervical tissues. Failure to recognise the condition may result in a fixed rotatory subluxation which can be difficult to treat. The authors report on two cases of atlantoaxial rotatory subluxation which occurred following pharyngoplasty and discuss the clinical presentation and management of these cases. The literature on this subject is briefly reviewed.

The aetiology of degenerative disease of the hip. A review of 400 cases

Four-hundred and forty patients who presented for Total Hip Replacement to the Orthopaedic Hospital, Cappagh were included in this study. Each case was classified into radiographic and aetiologic groups on the basis of the patients history, the results of special investigations, and the radiographic appearance of the hips. This classification allowed a further differentiation into primary and secondary osteoarthritis. Primary or idiopathic osteoarthritis was the single most common aetiologic group. A surprisingly high percentage of patients with secondary osteoarthritis had congenital dysplasia. It is suggested that this faulty biomechanical situation is the initiator of subsequent joint degeneration due to stress loading on the supero-lateral border of the hip. The reasons why such changes may be delayed until the 6th and 7th decades are unclear but degeneration once started progresses quickly. The possible place of surgical correction of the underlying biomechanical fault in delaying or preventing the onset of osteoarthritis is demonstrated and discussed.

The multidisciplinary feeding profile: a statistically based protocol for assessment of dependent feeders

The development of the multidisciplinary feeding profile entailed a level of statistical analyses not commonly utilized in test development. This paper describes the statistical analyses and offers an explanation of why specific statistical tests were chosen. It also serves to identify where clinical knowledge and experience overrode specific statistical tests.

Development of a multidisciplinary feeding profile for children who are dependent feeders

The multidisciplinary feeding profile (MFP) is the first statistically based protocol for the quantitative assessment of feeding disorders in severely disabled children. This assessment can be completed in 30-45 min with foods and facilities that are available in homes, hospitals, and chronic care units. This paper describes the state of current testing methods, the parameters of successful feeding activity, the development of the test protocol, and the results of statistical analyses.

The diagnostic value of facet joint injections

This study evaluates the specificity of facet joint injections in diagnosing symptomatic facet joint pain. Fifty-four patients had 143 facet joint injections performed in a prospective study. Pain provocation and pain relief were used to confirm the diagnosis. All patients had symptoms and signs considered suggestive of facet joint pain. Less than 1.5 ml of bupivacaine was injected into each joint to prevent extravasation. Only nine patients (16.7%) had the diagnosis confirmed, significantly lower than most published results. An anatomic study performed suggests that extravasation into the epidural space occurs following rupture of the joint capsule. This provides an explanation by which good therapeutic results can be obtained if large volumes of therapeutic agent are used.

Scaphoid fractures treated by Herbert screw fixation

Forty-one scaphoid fractures had Herbert screw fixation. There were three acutely displaced fractures (Type B), nine delayed unions (Type C), and 29 non-unions (Type D). All procedures were carried out by the senior author between December 1983 and May 1987. The average time from injury to surgery was 19 months. All Type D fractures were bone-grafted. Six of the 29 Type D fractures failed to unite radiologically following surgery. Incorrect screw placement was a factor in two cases. The average time from injury to surgery in three of the others was seven years. Radiological evidence of screw loosening was present within two months of mobilising these cases. We feel that Herbert screw fixation may not be adequate when dealing with longstanding scaphoid non-unions, and stronger fixation or prolonged cast immobilisation may be necessary.

Scaphoid Fractures Treated by Herbert Screw Fixation

Forty-one scaphoid fractures had Herbert screw fixation. There were three acutely displace fractures (Type B), nine delayed unions (Type C), and 29 non-unions (Type D). All procedures were carried out by the senior author between December 1983 and May 1987. The average time from injury to surgery was 19 months. All Type D fractures were bone-grafted.

Six of the 29 Type D fractures failed to unite radiologically following surgery. Incorrect screw placement was a factor in two cases. The average time from injury to surgery in three of the others was seven years. Radiological evidence of screw loosening was present within two months of mobilising these cases. We feel that Herbert screw fixation may not be adequate when dealing with longstanding scaphoid non-unions, and stronger fixation or prolonged cast immobilisation may be necessary.

Synthesis and pharmacological activity of angiotensin converting enzyme inhibitors: N-(mercaptoacyl)-4-substituted-(S)-prolines

The synthesis of a series of N-(mercaptoacyl)-4-substituted-(S)-prolines (2 and 3) is described. These compounds were evaluated in vitro for inhibition of angiotensin-converting enzyme (ACE), and selected compounds were evaluated in vivo for ACE inhibition. The most potent compounds in vitro are 108, 109, 111, 114, and 116, having relative potencies of 1.0, 1.0, 1.3, 1.1, and 2.6 as compared to the potency of captopril. The most potent compounds in vivo intravenously are 108, 111, 114, 116, 117, and 97.

Childhood Menetrier's disease: four new cases and discussion of the literature

Four cases of childhood Menetrier's disease are presented and their clinical and laboratory findings are compared with the other childhood cases reported in the literature. Children with Menetrier's disease usually present with abdominal pain or nausea and vomiting associated with peripheral edema, ascites, or pleural effusion; these symptoms are due to gastrointestinal protein loss and resultant hypoproteinemia. There is no evidence of urinary protein loss. The favorable clinical course as well as distinctive laboratory and roentgenologic findings distinguish this entity from other causes of these symptoms. Supportive therapy is normally all that is required since the symptoms resolve spontaneously in weeks to months. Surgery may be needed in rare cases of active gastrointestinal hemorrhage.

Detection of 5-bromodeoxyuridine (BrdUrd) incorporation by monoclonal antibodies: role of the DNA denaturation step

Immunochemical detection of cells that incorporate 5-bromodeoxyuridine (BrdUrd) requires prior denaturation of DNA in situ to make BrdUrd binding sites accessible to the antibodies. A technique is described in which the DNA denaturation step is facilitated by a) prior dissociation of histones from DNA and b) the use of low ionic strength buffer in which the cells are suspended during heating. Dissociation of histones is achieved by cell treatment with 0.08N HCl at 0 degree C, which a) increases accessibility of DNA to propidium iodide (and following the denaturation to the antibodies); b) lowers stability of DNA to thermal denaturation; c) decreases differences between various cell types due to variability in chromatin structure; and d) ensures more complete DNA denaturation. Cell heating (80-95 degrees C) at low ionic strength (1 mM Na+) eliminates the need for formamide and results in extensive and rapid DNA denaturation. The method was applied in Friend leukemia, L1210 and HL-60 cell lines, and to bone marrow, experimental animal tumor and primary human tumor cells.

The drooling patient: team evaluation and management

Drooling is a common problem in neurologically damaged individuals. A surgeon, speech pathologist, physiotherapist and dentist created a "team" to evaluate affected patients. Management by consensus involves both non-surgical and surgical modalities. Bilateral submandibular duct relocation has become the surgical procedure of choice.

Simultaneous MR imaging of both breasts using a dedicated receiver coil

We have designed and built a dedicated magnetic resonance (MR) coil that images both breasts simultaneously with the patient in a prone position, incorporates imaging advantages of surface coils, and benefits from having separate transmitter and receiver coils. This coil is compatible with a 0.15-T (6.3 MHz) resistive-magnet unit. It works as a simple plug-in replacement for the standard receiver coil. The unit's triple-coil structure consists of two outer coils that lie close to the lateral surface of the right and left breast and a central coil positioned between the breasts. A two-chambered box supports the coils. Breast-coil image-reception sensitivity is three to seven times greater than values obtained with a whole-body coil and shows a smooth spatial variation without oscillatory or sharply breaking behaviors. Increased sensitivity for breast tissue allows us, with a given imaging time, to use thinner sections (5 mm thick) than are possible with the whole-body coil. Since the coil is insensitive to organs such as heart and lung, motion artifact is eliminated, and image quality and resolution are further increased. Simultaneous imaging of both breasts allows direct comparison and increases patient throughput.

Angiotensin-converting enzyme inhibitory activity of SCH 31846, a new non-sulfhydryl inhibitor

SCH 31846, 1-(N-[1(S)-(ethoxycarbonyl)-3-phenylpropyl]-(S)-alanyl)-cis, syn-octahydro-(H-indole-2-S)-carboxylic acid; CI-907; PD 109, 763-2, is a new non-sulfhydryl-containing, angiotensin-converting enzyme (ACE) inhibitor. The present investigation describes its ACE inhibitory properties and compares them to those of MK 421. The diacid of SCH 31846 inhibited rabbit pulmonary ACE with an IC50 of 2.2 nM (MK 421 diacid 2.5 nM). The drug behaved as a competitive and specific inhibitor in vitro. SCH 31846 and its diacid effectively inhibited pressor actions of intravenous injection of angiotensin I (AI) in anesthetized rats. ID50 values were 27 and 11 micrograms/kg for SCH 31846 and SCH 31846 diacid, respectively (MK 421 and MK 421 diacid 57 and 15 micrograms/kg, respectively). Oral administration of SCH 31846 (0.03-1 mg/kg) inhibited pressor actions of AI in conscious rats with a duration of over 16 h at 0.3 and 1 mg/kg. SCH 31846 was 2.2 times as potent as MK 421 in this regard. The diacid of SCH 31846 was considerably less potent than the ester, implying poor oral absorption of the former. Effective ACE inhibition, as judged by attenuation of pressor actions of AI, was noted in dogs after both intravenous and oral administrations of SCH 31846. Onset of action was more rapid than that of MK 421. Intravenous administration of SCH 31846 inhibited the renal vascular actions of intrarenal injection of AI, indicating effective blockade of the renal enzyme. Intracerebroventricular administration of SCH 31846 diacid blocked pressor responses to intracerebroventricular AI, whereas oral administration of SCH 31846 (10 mg/kg) did not, implying that SCH 31846 inhibits brain ACE but does not gain access to the cerebral enzyme when administered orally. These data indicate that SCH 31846 is a potent and specific non-sulfhydryl ACE inhibitor. As such, it should be useful in the treatment of hypertension and heart failure.

Formulae for determination of chlorophyllous pigments extracted with n,n-dimethylformamide

The extraction of chlorophylls in higher plant tissue using N,N-dimethylformamide expedites the process and enables the determination of small samples with low pigment level.Absorption spectra of Chl a, Chl b, and Pchl and of their acidified derivatives, the phaeophytins, were recorded. Conversion of Chl b to its corresponding acidified product occurs much more slowly than that of Chl a and Pchl. When acidified, Pchl differs from Chl a and Chl b by the disappearance of the red band in the absorption spectrum. Specific extinction coefficients were determined and formulae for quantitative determination of pigments concentrations were developed. When concentrations of pigments are low, as in etiolated plant material, the absorption spectra of the chlorophylls can be distorted due to the presence of other substances simultaneously extracted; formulae for pigment determination under such circumstances were also derived.

Estrogen receptor heterogeneity and the relationship between estrogen receptor and the tritiated thymidine labeling index in human breast cancer

Tissue from 54 patients with breast cancer was analyzed for estrogen receptor (ER). From 38 patients, tissue from multiple tumor sites was analyzed to determine ER heterogeneity. In 13 patients (34%) both positive and negative ER values were obtained. ER negative (ER-) results were observed more frequently in metastatic lesions. In 28 patients both the ER and [3H]-thymidine labeling index (LI) were measured in the metastatic lesion. [3H]-Thymidine was administered in vivo. There was a positive correlation between ER positivity and low LI. The mean LI of 8 ER positive (ER+) tumors was 3.4 in contrast to a mean LI of 10.0 for 14 ER- tumors (p less than 0.01). LI of 6 mixed ER tumors (ER+/-) was intermediate (mean 5.7). High LI (greater than or equal to 8) was associated with decreased survival regardless of the stage of disease at the time of study. ER with LI may provide an improved basis for treatment selection.

Chemotherapy and cyclic radiation therapy in locally advanced non-small cell lung carcinoma

Nine patients with non-small cell lung carcinoma (4 squamous, 4 adenocarcinoma, 1 large cell) were treated with a combination of radiation therapy and cyclic chemotherapy with 5-fluorouracil, methotrexate and platinum. Four previously untreated patients had stage III, 2 having distant metastases, 5 previously treated patients were restaged as stage III with distant metastasis in one. Moderate hematologic toxicity was noted. Objective responses occurred in 67 per cent, regardless of previous treatment or performance status. Responders survived for a median of 11 months with one complete response patients surviving at 14 months while 5 partial response patients survived for a median of 10 months. This regimen is feasible and its utility as the initial treatment of locally advanced disease should be further investigated.

Influence of angiotensin converting enzyme inhibition with captopril on blood pressure and adrenergic function in normal and sodium restricted rats

Observations with both captopril and teprotide suggest interplay of the renin angiotensin and sympathetic nervous systems during sodium depletion. We therefore examined adrenergic responses in normal or sodium restricted (8 days low sodium chow; trichlormethiazide 3 mg/kg, p.o., days 5-7) normotensive rats orally pretreated with placebo and captopril (3 or 10 mg/kg; twice on day 7, once on day 8) and pithed 2 hrs after the last dose. Consistent hypotension in conscious intact animals was observed only in sodium-depleted groups receiving captopril. Pressor responses to low frequency (2.5 Hz--5 sec) sympathetic stimulation and phenylephrine were reduced in normal sodium, pithed normotensive Sprague-Dawley rats receiving 10, but not 3 mg/kg captopril and low sodium animals receiving both doses. Suppression of phenylephrine by captopril was accentuated in sodium-depleted groups. Pressor responses to angiotensin II were less in all salt-depleted animals receiving either placebo or captopril. Captopril failed to reduce tachycardia to either sympathetic nerve stimulation or isoproterenol. These effects of captopril suggest that angiotensin plays a role in maintenance of vascular, but not cardiac adrenergic function. This role is manifested at a post-junctional site and becomes critical in the sodium deficient state.

Chlorophyll determination in intact tissues using n,n-dimethylformamide

Photosynthetic pigments from etiolated cucumber (Cucumis sativus var. Beit Alpha improved, Hazera Co., Gedera) cotyledons were extracted by direct immersion of the intact cotyledons into the solvent N,N-dimethylformamide (DMF). The solvent is especially efficient when pigment concentration is low; time and tools are saved and the loss of pigment that usually occurs in more complicated extraction procedures is prevented. The specific absorption coefficient of chlorophyll a in DMF was also determined.