[Clinical relevance of whole body skeletal scintigraphy in multiple injury and polytrauma patients]

The provision of care to polytraumatised patients is a particular diagnostic and therapeutic challenge. The examination data of 162 polytraumatised patients were retrospectively investigated to determine the diagnostic gain provided by skeletal scintigraphy with 99mTc-HMDP. It was found that every fresh fracture (with the exception of fractures to the skull) led to a scintigraphically clearly demonstrable remodelling reaction within ten to 14 days. The timing of the examination was of decisive importance for the information yield. Not until about the tenth to 12th day did also those fractures that showed a delayed uptake show adequately signal-intensive areas of uptake in the scintigram. Typical examples were additional fractures of the spine and pelvis in patients immobilised by fractures of the limbs. At this time, with the aim of skeletal scintigraphy, an additional fracture was found in half of all patients, and was subsequently verified radiologically. Additional diagnostic information is independent of the ability of the patient to cooperate. This was of particular importance in the case of the very severely injured and old patients. Skeletal scintigraphy can be employed with equal efficacy to reliably exclude bone injuries. Thus, skeletal scintigraphy if of particular significance in the determination of the extent of bone injury in polytraumatised patients. This applies in particular to the preparation of an expertise. Thus, as in the case of staging of malignomas, the additional performance of bone scanning twelve to 14 days after traumatisation should form part of routine care offered to polytraumatised patients.

[Symptomatic cholecystolithiasis: 1992 therapy options]

Modern treatment of symptomatic cholecystolithiasis requires a knowledge of several nonsurgical and surgical treatment options. Extracorporeal shock-wave lithotripsy and oral bile acid therapy offer the possibilities of noninvasive, outpatient treatment in approximately 20% of all symptomatic gallstone patients at a low complication rate. The percutaneous interventional techniques such as contact dissolution by means of ether or mechanical stone removal may in principle be used in a higher percentage of patients but are considerably more invasive. None of the nonsurgical techniques can exclude the relative risk of gallstone recurrence. Laparoscopic cholecystectomy constitutes a major progress in the surgical treatment of gallstone disease, since it is much less invasive than conventional cholecystectomy and requires a much shorter hospital stay and recovery time. The laparoscopic technique is primarily indicated in patients with symptomatic, uncomplicated cholecystolithiasis. Nevertheless, the range of indications is expanding as experience with this technique increases. Under certain circumstances, laparoscopic cholecystectomy is already being combined with endoscopic sphincterotomy in the presence of bile duct calculi. Conventional cholecystectomy remains the treatment of choice for complicated cases.

Pharmacokinetics of nimodipine in multimorbid elderly patients with chronic brain failure

Twenty-one elderly patients with chronic brain failure received a single 30 mg oral dose of the calcium channel blocker nimodipine followed by two weeks of 30 mg three times a day (t.i.d.) administration. The aim of this study was to assess if drug accumulation occurred in our frail elderly subjects under this dose regimen. Plasma concentrations of nimodipine and three main metabolites were determined by gas chromatography. During the 2-week period we did not find significant changes in peak plasma concentrations and corresponding areas under the plasma concentration-time curves. Trough nimodipine plasma concentrations before administration of the morning dose were similar on days 7 and 14. Therefore, no evidence of drug accumulation was found. Blood pressure and heart rate remained stable throughout the study period and no adverse effects were observed. During the study period, there was a decline in the proportion of patients who complained about dizziness and insomnia. Overall, our data suggest that there is no need to alter the usual adult dose of nimodipine if this drug is administered to multimorbid frail elderly patients suffering from chronic brain failure.

[Leipzig Medical Society (founded in 1829)]

The Leipzig Medical Society was founded in 1829 by Justus Radius. More than 100 years this interdisciplinary association was a scientific and cultural centre which promoted scientific life and professional training of the municipal physicians and the university staff. Therefore the Leipzig Medical Society contributed to reputation of Leipzig as an cultural and scientific centre during the last years of the 19th and the beginning of the 20th century.

Preliminary studies on the vascular anatomy of the equine superficial digital flexor tendon

The vascular and microvascular anatomy of normal equine superficial digital flexor tendons was studied by dissection of vinyl-perfused specimens and by microangiography on high detail film. The presence of an extensive intratendinous vascular latticework was confirmed, and a 'nutrient artery' described closely associated with the accessory ligament of the superficial digital flexor tendon (proximal check ligament). Circumferential stripping of the paratenon from the tendon to eliminate afferent vessels was performed bilaterally in three horses and unilaterally in a fourth, followed by a treadmill training regimen. No resulting intratendinous lesions could be documented on gross post mortem and histological examination at three, 10, or 35 days post operatively. There was mild paratendinous proliferation in all instances. In one horse, four intratendinous ligatures were placed within the medial and lateral borders of the contralateral tendon to isolate further from its blood supply a 10 cm segment. Gross lesions at 35 days post operatively included a marked paratendinous response involving the entire 10 cm segment, and a darkened, soft focus within the core of the tendon. Histopathology and electron microscopy demonstrated focal degeneration. It was concluded that the blood supply of the normal equine superficial digital flexor tendon is primarily intratendinous, rather than paratendinous as previously thought. The lesions in one horse similar to those in naturally occurring tendinitis supported a vascular aetiology of the disease, and set the groundwork for studies aimed at the development of a clinically relevant tendinitis model.

[Clinical pharmacokinetics of lidocaine after intraoral nerve block]

Aim of this study was to show the time course of plasma concentrations of 2% lignocaine with adrenalin at a concentration of 1:100,000. Four retinated third molars were removed in one session in 23 patients. For local anaesthesia in each patient we used 10 ml of Xylocaine 2% (Astra), which is commonly used in dentistry. The plasma-concentration was measured for the first 30 minutes after injection of the local anaesthetic using high pressure liquid chromatography (HPLC). Our results suggest that partially intravascular injection could not be avoided although careful aspiration was carried out before injecting. Neither subjective nor objective adverse central nervous effects were seen in our patients. Nevertheless we consider a peripheral intravenous cannula and ECG-monitoring strongly recommended in all major operations under local anaesthesia.

Fatal injuries at work in California

We examined deaths due to injury on the job reported from three readily accessible data sources in California for a 1-year period. Of 682 deaths identified as of February 1990 as having occurred on the job in 1983, county coroners identified 607 (89.0%), workers' compensation records identified 294 (43.1%), and the California Occupational Safety and Health Administration investigated 141 (20.7%). Most fatal injuries at work resulted from events that are not covered by current California Occupational Safety and Health Administration standards: transportation vehicle accidents and homicides. Demographic patterns suggest that fatal injuries on the job are nonrandom events, which may be prevented by additions to existing standards or increased enforcement of workplace safety standards and by efforts to target groups at highest risk. Improved surveillance of fatal occupational injuries will require changes in existing reporting mechanisms, similar to those proposed by the US Bureau of Labor Statistics.

Comparison of iohexol with barium in gastrointestinal studies of infants and children

This study evaluates iohexol as a contrast agent in the gastrointestinal tract in children. In the first part of the study, iohexol in concentrations of 180 and 300 mg l/ml was compared in double-blind manner with barium. Sixty-four patients were studied. No significant difference in changes of blood pressure and pulse rate was found between the three groups of patients studied. Diarrhea was significantly more common in the children receiving iohexol than in children receiving barium. The diarrhea was not due to previously identified high-risk factors in the children, nor was it due to concurrent medication. When image quality was assessed in each anatomic region of the gastrointestinal tract, fewer nondiagnostic ratings occurred with barium than with iohexol. With barium, fewer ratings of poor mucosal coating and slightly fewer ratings of suboptimal contrast density occurred. The second part of the study was an open evaluation of iohexol 180 mg l/ml in 18 patients in whom barium was clinically contraindicated. Three of 53 assessments were nondiagnostic. Mucosal coating was poor in 6%, and contrast density was suboptimal in 8% of patients. The results of this study indicate that barium is the preferred contrast agent for routine evaluation of the gastrointestinal tract in children. Good-quality images can be obtained, however, with iohexol in concentrations of 180 or 300 mg l/ml, and iohexol is an excellent contrast agent for evaluation of the gastrointestinal tract in those patients in whom barium is relatively or absolutely contraindicated.

The community hospital-based stroke programs in North Carolina, Oregon and New York--V. Stroke diagnosis: factors influencing the diagnostic evaluation of patients following acute stroke

Among the 4129 patients of the Community Hospital-based Stroke Program, 30% had an unspecified stroke diagnosis. Since specific diagnosis and, perhaps, eventual treatment, derives in part from diagnostic testing, we examined the effect of clinical condition, geographic and demographic factors on the incidence of certain diagnostic tests after acute stroke. In this multivariable analysis, race, sex, history of hypertension and history of diabetes did not influence the chance of having any test, but older age strongly reduced the chances of receiving extensive evaluation. When CT scanning was available, the utilization of a CT as well as other diagnostic studies including cerebral angiography, radionuclide brain scan, EEG and EKG was increased. The odds of receiving a CT scan increased if the patient was married, and decreased with a history of previous stroke. A history of previous TIA increased the chance of having a cerebral angiogram while a history of cardiac disease decreased the chance. There were striking regional geographic differences in the use of CT, radionuclide brain scanning and cerebral angiography which may, in part, reflect differences between the availability of these technologies in urban and rural hospitals. These results indicate that evaluation of stroke patients remains heterogenous.

Acute hamstring injuries in rugby players: The influence of positioning during ice therapy on muscle length

The effect on muscle length of positioning with ice application to acute hamstring injuries in rugby players was examined. Ice was applied with the hamstring muscle group in either the lengthened or the shortened position. Players with grade I or II hamstring injuries were randomly allocated (via the randomized block method) to the different treatment methods. The active hamstring length of the injured leg was measured by means of knee extension before and after treatment on days 1, 2 and 3 post-injury. The uninjured leg was measured on days 1 and 3.The discussion of results covered only the clinical observations since the experimental group was too small for statistical analysis.

Differential expression by nerve growth factor of two types of Ca2+ channels in rat phaeochromocytoma cell lines

1. Two clones of rat phaeochromocytoma PC12 cells have been used to study the expression of Ca2+ channels and their possible involvement in neuronal differentiation. One clone differentiated morphologically when exposed to nerve growth factor (NGF) for 4 days (PC12 cells), while the other clone was insensitive to NGF, but differentiated morphologically in the presence of ouabain (0.1 mM) for 7 days (PC12-mutant cells). 2. Whole-cell Ba2+ currents through Ca2+ channels were measured in PC12 cells at a test potential (Et) of +10 mV, from two holding potentials (Eh) of -90 and -30 mV (I-90 and I-30). NGF-induced differentiation increased I-90 by 248% and I-30 by 133%. The cells that differentiate in the presence of ouabain had only small, if any, Ba2+ currents that did not appear to change during morphological differentiation or after the addition of NGF. 3. Barium currents in PC12 cells could be separated into two components by selective antagonists. The component of I-90 that could be inhibited by omega-conotoxin GVIA (omega-CgTX) in NGF-differentiated cells was 458 +/- 84 pA (mean +/- S.E.M.), compared with 79 +/- 44 pA in native cells. I-30 was reduced by 50 +/- 17 pA in NGF-treated cells and was virtually insensitive to the toxin in native cells. By contrast, the dihydropyridine (DHP) isradipine reduced I-30 in NGF-treated cells by 30 +/- 8 pA and in native cells by 20 +/- 3 pA. 4. Radioligand binding studies with 125I-omega-CgTX in PC12 cell membrane fragments and in PC12 cells showed a 2- to 3-fold increase in maximal binding capacity after NGF exposure, while mutant cells showed no such change in binding capacity after treatment with NGF or ouabain. Staurosporine inhibited the effect of NGF on 125I-omega-CgTX binding. [3H](+)-isradipine binding capacity was increased 1.8-fold by NGF in depolarized PC12 cells while no change was observed in mutant cells after NGF or ouabain. There was no interaction between omega-CgTX and DHP binding sites. 5. Both the electrophysiological and the binding data indicate a preferential expression of omega-CgTX-sensitive Ca2+ channels (N type) over isradipine-sensitive channels (L type) in PC12 cells treated with NGF. By contrast, ouabain-induced differentiation of a mutant PC12 cell line, that lacks functional NFG receptors, was not associated with the expression of Ca2+ channels.

Community hospital-based stroke programs in North Carolina, Oregon, and New York. IV. Stroke diagnosis and its relation to demographics, risk factors, and clinical status after stroke

The use of diagnostic tests, the accuracy of stroke type diagnosis, and their relationship to outcome are important from the standpoint of patient management and health care costs. To address this issue, we examined the differences between stroke types in terms of demographics, risk factors, diagnostic tests, and clinical outcome in the 4,129 patients who comprise the Community Hospital-Based Stroke Program. Previous transient ischemic attacks were equally frequent among patients with embolic and those with thrombotic stroke. For all stroke types, previous stroke was as frequent as previous transient ischemic attacks. Hypertension and cardiac disease were the most common risk factors, but 10% of all stroke patients had no recognized risk factors. Intracerebral hemorrhage was most often associated with death (45%). There was a strong direct relation between in-hospital mortality and a decreased level of consciousness at admission. Overall, 30% of patients did not receive a specific stroke type diagnosis; these patients were elderly, usually nonwhite, and often had an altered level of consciousness at admission but had a risk factor profile similar to that of patients who received a specific stroke type diagnosis. In summary, our findings suggest the continued need for physician education about and refinement of stroke type diagnosis.

Inhibition of palmitoyl co-enzyme A hydrolase in mitochondria and microsomes by pharmaceutical organic anions

Rat microsomes and mitochondria were isolated and incubated with selected pharmaceutical organic anions at concentrations of 0, 0.2, 0.5, 1.0, and 2 mM. Activity of palmitoyl CoA hydrolase (PCAH) was shown to be reduced in a dose-dependent manner in microsomes by ibuprofen, valproate, acetyl salicylate, 2,4-dichlorophenoxyacetate (2,4-D), and 4-pentenoate, but not salicylate. Mitochondrial PCAH activity was inhibited by clofibrate, ibuprofen, valproate, and 2,4-D. Mitochondrial oxidative phosphorylation was impaired or uncoupled by each of the mitochondrial PCAH inhibitors. The inhibition of PCAH by some of these agents may lead to fatty acyl CoA accumulation. Very low concentrations of fatty acyl CoA are known to cause mitochondrial uncoupling and increase permeability. This action may play a role in the mitochondrial injury caused by some of these agents or related disease processes.

The effects of a progestin-only oral contraceptive (levonorgestrel 0.03 mg) on breast-feeding

This study was a non-randomized clinical trial which compared the breast-feeding experience of 250 Argentine women taking levonorgestrel 0.03 mg daily (begun one week after delivery) with that of 250 women using non-hormonal contraceptives. Weight gain of unsupplemented infants, the most important of the several criteria used to assess breast-feeding performance, was similar for the two contraceptive groups. Levonorgestrel users began supplementary feeding of their infants significantly later than did non-hormonal users; levonorgestrel users were also somewhat less likely to discontinue breast-feeding during the study period. The two contraceptive groups were similar with regard to several other measures of breast-feeding performance: growth of all infants (regardless of supplementation), patterns of contraceptive discontinuation, mothers' subjective impressions of breast-milk sufficiency, and comparison of supplementation initiation with previous experience.

Increased muscle regeneration after repair of divided motor nerve with neuronotrophic factors containing glue

Neuronotrophic factors (NTFs) directed to spinal cord motor neurons were collected in rats within silicone nerve regeneration chambers according to LONGO et al. (1983b). Unilateral addition of NTFs to the fibrin glue used for the repair of divided sciatic nerves improved locally nerve regeneration without affecting the controlateral side. Nerve regeneration was assessed by weight gain of the reinnervated muscles and by radioactive labelling of the acid-soluble phosphate fractions of both nerve Schwann cells and reinnervated muscle cells. Fast gastrocnemius and slow soleus muscles, the motor nerve of which had been repaired with added NTFs, were significantly heavier (21 and 28%) than their controlateral controls, and the metabolic dedifferentiation attendant on post-division nerve repair was less marked. It is suggested that this experimental nerve regeneration model is suitable to test potential nerve-active agents in vivo, under conditions close to the usual clinical setting, with, as ultimate goal, the improvement of the end-results of microsurgical repair of peripheral nerve in man.

Changes in survival following stroke in five North Carolina counties observed during two different periods

We evaluated survival following stroke for patients from a five-county area of rural North Carolina enrolled in either of two community hospital-based stroke survey programs. In this area, the first program enrolled 843 stroke patients between 1970 and 1973 and the second program enrolled 786 stroke patients between 1979 and 1980. One-year survival increased from 49% in the first program to 62% in the second for all stroke patients, from 54% to 68% for patients with cerebral infarction, and from 18% to 55% for patients with cerebral hemorrhage. While other reports have attributed declining stroke mortality to a decline in the incidence of stroke, our study suggests that increased survival after stroke may account for a large portion of the decrease in stroke mortality.

Using chromatography in downstream processing

This article concludes the series on the use of chromatography for downstream processing. Although it has only scratched the surface when considering the number of parameters involved in process chromatography, it does give a broad overview including the choice of components through process standards. Pharmacia LKB Biotechnology has had more than 15 years experience in the design development and running of large scale chromatographic processes. During this time the company has gathered a vast amount of experience and information on the key points to successful product purification. Pharmacia LKB can advise on the choice of techniques and the development of a separation process up to full production scale.

Potential-dependent allosteric modulation of 1,4-dihydropyridine binding by d-(cis)-diltiazem and (+/-)-verapamil in living cardiac cells

We have studied allosteric effects of the Ca channel blockers d-(cis)-diltiazem, (+/-)-verapamil, and (S)- and (R)-devapamil on the specific binding of the 1,4-dihydropyridine derivative (+)-[3H]PN 200-110 to intact tissue cultured rat heart cells. In polarized cells (membrane potential, -38 +/- 4 mV) d-(cis)-diltiazem (5 microM) increased the affinity of the radiolabel 2-4-fold causing 100-187% enhancement of binding at (+)-PN 200-110 concentrations below 0.5 nM. (+/-)-Verapamil (0.1-3 microM) had a similar, although smaller, effect on (+)-PN 200-110 binding. The two enantiomers of devapamil were without effect. In depolarized cells (membrane potential, 0 mV) d-(cis)-diltiazem had a small and the phenylalkylamines a strong inhibitory effect on (+)-PN 200-110 binding, mainly due to a reduction of binding affinity. At 50% receptor occupation by the radioligand, (R)-devapamil, (+/-)-verapamil, and (S)-devapamil displaced 40, 55, and 75%, respectively, of specifically bound radiolabel. Half-maximal effects were reached with 50, 20, and 4.5 nM, respectively, of the three compounds. Compared with nominally Ca-free medium (containing 3-5 microM Ca), addition of 1.25 mM CaCl2 caused an increase in the maximal binding capacity for (+)-PN 200-110 in both polarized and depolarized cells. However, Ca had only marginal effects on the allosteric interactions between (+)-PN 200-110, d-(cis)-diltiazem, and verapamil. We conclude from our results that positive cooperative interactions between Ca channel blockers prevail under conditions in which the voltage-dependent Ca channel can fluctuate between closed, open, and inactivated states. Negative cooperativity is usually observed under conditions in which all channels are inactivated (depolarized cells, fragmented membranes). Therefore, it is impossible to predict the type and the extent of allosteric interactions in vivo from studies in cell homogenates.

[The ulnar flap]

A new skin or fascial flap is described, based on the dorsal ulnar artery. In hundred fresh cadaveric forearms this vessel was constant with a diameter of 1 to 1.3 mm, passing dorsally from the ulnar artery deep to the flexor carpi ulnaris muscle. It supplies the skin and the fascia in the distal two thirds of the ulnar side of the forearm (length from 9 to 20 cm; width 1.5 to 10 cm). A flap based on this vessel can cover defects of the dorsal and palmar aspects of the hand and wrist, the thenar and the hypothenar eminence. It can be used as a fascial flap to avoid fibrosis around the median nerve and the tendons. The authors show the anatomy and some clinical cases.

A blind trial of silicone chamber fluid in nerve regeneration in the rat

The nerve growth-promoting effects of the fluid accumulating in vivo from 1 to 28 days within silicone chambers were tested on the sciatic nerves of rats. We measured the elongation of sensory axons following nerve transection repaired by means of fibrin sealant allowing local application of the fluid. We found no difference between transections treated with chamber fluid and controls.

[The cubital flap]

The authors describe a flap with a pedicle derived from the dorsal branch of the ulnar artery. The ulnar artery gives rise to the dorsal ulnar artery 2 to 5 cm before the pisiform. This artery passes under the flexor carpi ulnaris muscle, accompanied by the dorsal branch of the ulnar nerve. It supplies an area 10 to 20 cm long by 5 to 9 cm wide on the ulnar side of the forearm and it also supplies the skin lying over the last three metacarpals on the dorsum of the hand and the Vth abductor. This artery also sends a branch to flexor carpi ulnaris and to the pisiform. It is now possible to trace a large flap in the forearm without interrupting the arterial axis. Large defects of the dorsum of the hand, wrist, thenar and hypothenar eminences can be covered by this pedicle or island flap. This artery is remarkably constant. Five clinical cases are presented.

Pericardial effusion causes interstitial pulmonary edema in dogs

The pulmonary effects of pericardial effusion were studied in eight anesthetized dogs, with emphasis on lung mechanics, O2 exchange, and extravascular thermal lung volume (ETV) accumulation, while warm saline was instilled into the pericardium to elevate pericardial pressure. The results were compared with those from four time-controlled and sham-operated dogs. ETV, as measured by a double-indicator technique, increased from 8.1 +/- 0.8 ml/kg at a pericardial pressure of 0 mm Hg to 12.9 +/- 2.1 ml/kg at 11.0 mm Hg (p less than .01). In the control group, ETV increased from 6.5 +/- 0.7 to 8.2 +/- 0.5 ml/kg over an equal time span. This increase in ETV in the experimental dogs was inversely related to pulmonary compliance, which decreased by 29% as ETV increased (p less than .05), whereas in the time-controlled group of animals it decreased by 8.8%. Arterial PO2 did not deteriorate during the protocol in either group. Histologic examination showed increased interstitial fluid, but neither alveolar fluid nor septal edema, and gravimetric measurements of lung liquid were also consistent with interstitial fluid accumulation in experimental but not control animals. These findings are concordant with the clinical observation that alveolar edema is rarely seen in the presence of pericardial tamponade. Conceivably, progression from interstitial to alveolar edema did not occur both because of the low pulmonary blood flow that occurs as part of pericardial tamponade physiology and/or because the hydrostatic pressures were not elevated enough to produce higher rates of fluid transudation.

Mutagenicity experiments on agroclavines, new natural antineoplastic compounds

Agroclavine, an alkaloid produced by some species of fungi and dicotyledon plants, and its 1-alkylated derivatives are potentially useful as antineoplastic drugs, since they exert potent and selective cytostatic effects. In the present study, we have investigated agroclavine and its 1-propyl and 1-pentyl derivatives for mutagenicity. The genetic end point studied was the reversion of strains of Salmonella typhimurium (TA 100, TA 98, TA 1537) and Escherichia coli (WP2 uvrA), auxotrophic for histidine and tryptophan, respectively. The compounds were tested directly and in the presence of a mammalian xenobiotic-metabolizing system. In the direct test, agroclavine and the two alkylated derivatives examined exhibited substantial bacteriotoxicity but no mutagenicity. Addition of NADPH-fortified postmitochondrial supernatant fraction of rat liver homogenate led to a clear-cut decrease in bacteriotoxicity and to the formation of mutagenic products. Each compound was effective in all three strains of S. typhimurium used. In E. coli only spurious effects were seen. 1-Pentylagroclavine, the most hydrophobic compound in the series, was the strongest mutagen. Agroclavine, the least hydrophobic compound, was the weakest. The mutagenic potencies and efficacies of all these test compounds were much weaker than those of the positive controls, which were known mutagens and carcinogens. Moreover, the differential effect of metabolism by liver enzymes demonstrates that the toxicity and mutagenicity of agroclavine and its derivatives are caused by different chemical species. Hence, it may be possible to develop derivatives that are cytotoxic but not mutagenic.

Differential effects of various secretagogues on quantal transmitter release from mouse motor nerve terminals treated with botulinum A and tetanus toxin

Electrophysiological and electron microscopic techniques were used to investigate the actions of potassium depolarization, black widow venom (BWSV), Ca2+-ionophore A 23187 and hyperosmotic solution on mouse hemidiaphragms poisoned in vitro with botulinum A toxin (BoTx) and tetanus toxin (TeTx). These neurotoxins reduced the frequency of miniature endplate potentials (m.e.p.ps) from 5/s of the control to 2/min and 21/min, respectively. High potassium (25 mmol/l) increased the m.e.p.p.-frequency at BoTx- and TeTx-poisoned endplates to 30/min and 50/s, respectively. The ultrastructure of endplates showed no obvious changes. BWSV (0.04 glands/ml) was just as effective in promoting transmitter release from BoTx-treated endplates as in control preparations. Electron micrographs revealed depletion of vesicles as well as swollen and disrupted mitochondria. When preparations were pretreated with TeTx, BWSV only moderately increased transmitter release and no alterations of the ultrastructure could be observed. At TeTx- or BoTx-poisoned endplates Ca2+-ionophore A 23187 usually produced an extreme reduction of m.e.p.p.-frequency (0.005/s), sometimes preceded by a short burst-like release. The ultrastructure of these endplates was not obviously affected. Application of hyperosmotic solution to BoTx- or TeTx-poisoned preparations further reduced the already low m.e.p.p.-frequency. These results further demonstrate that TeTx and BoTx act at different sites in the transmitter releasing process.

Studies on Ca channels in intact cardiac cells: voltage-dependent effects and cooperative interactions of dihydropyridine enantiomers

We have investigated the effects of two oppositely acting enantiomers of the 1,4-dihydropyridine derivative 202-791 on voltage-dependent Ca channels by combining electrophysiological techniques and binding studies. The (S)-enantiomer of 202-791 promoting prolonged openings of single Ca channels, and thereby increasing transmembrane Ba currents, was classified as channel activator. The (R)-enantiomer favoring a closed state of the channel, and thereby reducing Ba currents, was classified as a channel blocker. Both compounds shifted the steady state current inactivation curve toward more negative potentials. At holding potentials positive to -20 mV, the Ca channel-activating effect of the (S)-enantiomer turned over into a blocking effect. In cells with normal resting potential the combination of the two enantiomers revealed a possible positive cooperative effect resulting in an enhancement of the open state probability of the channels. At depolarized holding potentials the activator enhanced the inhibitory effect of the blocker. Binding studies in intact cells were performed by using the radiolabeled channel-blocking dihydropyridine 3H-(+)-PN 200-110. The results showed a strong increase in binding affinity but no change in binding capacity when the cells were depolarized. Analysis of the interactions of (S)- and (R)-202-791 with this radioligand indicated stimulation of 3H-(+)-PN 200-110 binding by the (S)-enantiomer in polarized cells (membrane potential -38 +/- 4 mV). This effect could be attributed to an increase in binding affinity. The (R)-enantiomer had no such positive cooperative effect, but acted as a purely competitive ligand. Depolarization to 0 mV increased the apparent affinity of both enantiomers by factors of 38 (blocker) and 12 (activator), but abolished the cooperative effect of (S)-202-791 on the binding of the radioligand. Ca ions had little effect on the binding of 3H-(+)-PN 200-110 in polarized cells. However, in the presence of the activating (S)-enantiomer, Ca transformed the usual hyperbolic binding isotherm of the radioligand into a strongly sigmoid curve. Sigmoidicity was minimal with 3-5 microM Ca and maximal with 0.5 mM Ca. Together these data demonstrate homotropic and heterotropic cooperative interactions between channel activator and channel blocker. They indicate that at least two high affinity binding sites for dihydropyridines are associated with voltage-dependent Ca channels. Voltage dependence of both--binding affinity and cooperativity--suggests that these binding sites are located close to a structural component of the channel which is involved in the potential-sensitive gating process.

Clavines as antitumor agents, 3: Cytostatic activity and structure/activity relationships of 1-alkyl agroclavines and 6-alkyl 6-noragroclavines

The cytostatic potential of twenty antibiotic agroclavines has been examined in the L5178y mouse lymphoma cell system. Twelve of these compounds are described for the first time. It is shown that the substituent at N-1 of agroclavine is very important whereas the substituent at N-6 is of less influence if it is not hydrogen. Incorporation studies in the presence of 1-propylagroclavine suggest that DNA synthesis in the lymphoma cells is inhibited. The effect on the corresponding [3H]thymidine incorporation in murine spleen lymphocytes is comparably low. Neither a significant change of mRNA efflux nor of DNA polymerase alpha and beta activities was caused. The mechanism of action seems to be a fundamentally new one for ergoline compounds as interactions with alpha-adrenoceptors, dopamine and 5-hydroxytryptamine receptors are not involved.

Evaluation of the North Carolina Stroke Care Program

A study of 774 patients in eastern North Carolina was undertaken to determine the effects of a coordinated program of care and follow-up on recovery from stroke. The program was designed to coordinate and improve in-hospital stroke care and rehabilitation, to provide for education and training of the family for post-hospital care, and to coordinate and facilitate continued access to services after discharge. As measured by the Barthel Index at discharge, three, six and 12 months, the impact of the program was found to be minimal. Patients' scores throughout follow-up were influenced by age, whether the stroke event was new or recurrent, and the state of consciousness at admission. Follow-up Barthel scores were also related to scores obtained at discharge.

Community Hospital-based Stroke Programs: North Carolina, Oregon, and New York. I: Goals, objectives, and data collection procedures

In order to assess the impact of variations in stroke care on outcomes, and to make geographic comparisons, the three Community Hospital-Based Stroke Programs in North Carolina, Oregon, and New York, aggregated their data on 4,132 hospitalized stroke patients. Complete demographic data or "Major Profile" were obtained on 2,390 (57.8%) of the 4,132 stroke patients. This includes those patients on whom informed patient and physician consents were obtained during the hospitalization. Of the major profile patients, 1,490 (62.3%) were followed for periods up to one year, 502 (21.0%) were lost to followup and 398 (16.6%) died within the one year followup period. Incomplete demographic data or "Minor Profile" were observed on 1,742 (42.1%) of the 4,132 patients. Minor profile includes those who died before comprehensive interviews were completed or those for whom informed consent for an interview could not be obtained. Of the minor profile group, 813 (46.7%) died in hospital, and 929 (53.3%) were alive when discharged from the hospital. This paper, which describes the programs, data collection procedures, and study cases, also highlights specific issues on stroke diagnosis, risk factors associated with stroke, and the influence of interventions on stroke outcomes. We conclude that: 1) the merging of data on hospitalized stroke cases from rural and urban hospitals in geographically distinct regions can be used in the study of stroke diagnosis, the use of diagnostic tests, and the effect of interventions on stroke outcomes; and 2) these data are consistent with the hypothesis that part of the national decline in mortality from stroke is due to a decline in stroke severity.

Community Hospital-based Stroke Programs: North Carolina, Oregon, and New York. II: Description of study population

The three Community Hospital-based Stroke Programs collected data on 4132 stroke patients admitted to acute care hospitals during 1979 and 1980. White female stroke patients were older than the white male, nonwhite female and nonwhite male stroke patients. Nearly one-fourth (23%) of stroke patients were employed at the time of the event. Most (77%) of the patients were hospitalized for first stroke episodes. Eighty-three percent of the patients had at least one of the four major risk factors for stroke, namely, hypertension, diabetes, transient ischemic attacks and cardiac disease. Half (49%) of the patients were alert at the time of admission. The three diagnostic categories included infarction (60%), stroke not otherwise specified (30%) and hemorrhage (10%). Fourteen days was the median length of hospitalization; 50% of the stroke patients were discharged to a home setting, 31% were institutionalized and 19% died while in the hospital. The mean Barthel Index score for 2400 patients at the time of discharge was 61.8 (normal is 100). Of those patients who were working at the time of the stroke, 22% returned to work. In comparison to the patients in the National Survey of Stroke, patients in this Study were less severe at the time of admission (49% of patients in the National Survey of Stroke were stuporous or comatose compared to 21% of the patients in the current Study). The inhospital fatality was 30.7% in the National Survey of Stroke, and 19.7% in the current Study.

Community Hospital-based Stroke Programs: North Carolina, Oregon, and New York. III. Factors influencing survival after stroke: proportional hazards analysis of 4219 patients

The possible effect of age, race, sex, consciousness upon admission, geographic location, and history of selected risk factors on the survival after stroke due to infarction or hemorrhage was determined using proportional hazards analysis (Cox regression). For each diagnostic category the most significant prognostic factor was consciousness upon admission. Increasing age, cardiac disease, or previous stroke also decreased the survival time of patients with infarctions. For patients with cerebral hemorrhage, no other variable was significant after control for consciousness level.

Pilot survey of urinary porphyrins from persons transiently exposed to a PCB transformer fire

In rats and humans chronically exposed to large amounts of PCB (polychlorinated biphenyls) and PCDF (polychlorinated dibenzofurans), the urinary excretion of uroporphyrin and coproporphyrin are altered. However, porphyrin excretion in humans after acute transient low level exposure has not been evaluated. Following such an exposure in which bystanders and firefighters were in contact with smoke from a PCB transformer fire, we surveyed 90 self-referred individuals by questionnaire and by determining single 24 hour urinary excretion of uroporphyrin and coproporphyrin 2-4 weeks after the fire. Questionnaire variables that assessed exposure were not associated with the magnitude of either uroporphyrin or coproporphyrin excretion. Uroporphyrin excretion was slightly elevated in nine subjects (range 66-106 micrograms/24 hours, normal less than 60), which is much less than in clinical cases of porphyria cutanea tarda. Uroporphyrin excretion was inversely correlated with coproporphyrin excretion (r = -0.3844, p = 0.0002). For 5 subjects (3 with elevated initial uroporphyrin excretion) retested at 3-4 weeks after the fire, all 5 showed increases in uroporphyrin and decreases in coproporphyrin excretion when compared to initial determinations. These two reciprocal relationships would be the expected result from inhibition of uroporphyrinogen decarboxylase, a known experimental effect of PCB and PCDF in mice. Overall, urinary porphyrin excretions were not altered or sensitive measures of exposure.

Acute effects of routine firefighting on lung function

We undertook a study to determine the acute effects of routine firefighting on lung function and the relationship between these acute effects and nonspecific airway responsiveness. For 29 firefighters from a single fire station, we calculated the concentration of methacholine aerosol that caused a 100% increase in specific airway resistance (Pc100). Over an 8-week period we than measured FEV1 and FVC in each firefighter before and after each 24-hr workshift and after every fire. From 199 individual workshifts without fires, we calculated the mean +/- 2 SD across-workshift change in FEV1 and FVC for each firefighter. Eighteen of 76 measurements obtained within 2 hr after a fire (24%) showed a greater than 2 SD fall in FEV1 and/or FVC compared to two of 199 obtained after routine workshifts without fires (1%; p less than .001). On 13 of 18 occasions when spirometry decreased significantly, we obtained repeat spirometry (postshift) 3-18.5 hr after fires, and on four of these occasions FEV1 and/or FVC were still more than 2 SD below baseline. Decrements in spirometry occurred as often in firefighters with high Pc100s as in those with low Pc100s. In two firefighters in whom FEV1 and FVC fell by more than 10% after fires, we repeated measurements of methacholine sensitivity, and it was increased over the prestudy baseline. These findings suggest that routine firefighting is associated with a high incidence of acute decrements in lung function.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro combination-effect of temocillin with ticarcillin and aminoglycosides on gram-negative and gram-positive bacteria

The in vitro efficacy of temocillin in combination with ticarcillin and with gentamicin, tobramycin, amikacin and netilmicin against 80 Gram-negative and 20 Gram-positive bacterial strains was compared by use of the checkerboard agar dilution technique. No synergistic or additive effect was seen on the Gram-positive strains. Great variations occurred between the different bacterial species, and the temocillin-ticarcillin combination had only little effect against the Pseudomonas strains tested. On average, only 12% of all strains tested were inhibited synergistically by temocillin-gentamicin combinations, and only 7 to 10% by combinations of temocillin with the other aminoglycosides. However, 25% of Gram-negative strains were inhibited synergistically and 40% of Gram-negative strains were inhibited additively by the combination of temocillin-gentamicin.

Avarol, a cytostatically active compound from the marine sponge Dysidea avara

A main metabolic product of the sponge Dysidea avara was isolated and purified and subsequently identified as avarol by applying a series of analytical techniques, e.g. [13C]NMR, [1H]NMR and i.r. spectroscopy. This sesquiterpenoid hydroquinone was found to possess strong cytostatic activity. Using the L5178y mouse lymphoma cell system in vitro (roller tube assays) avarol reduced cell growth to 50% at a concentration of 0.9 microM. Avarol treated cells did not show "unbalanced growth". Avarol interfered with mitotic processes, preventing telophase formation. Incorporation studies with precursors for DNA, RNA, protein and glycoprotein syntheses revealed increased incorporation rates in response to avarol treatment. From these results and further autoradiographical experiments it is suggested that inhibition of cell growth is due to changes of the intracellular pools and/or alterations of the permeability properties of the cell membrane for the precursors. Avarol diacetate caused the same cytostatic effect as avarol.

[Peripheral nerve repair: value of biological glues and epiperineural suture in late interventions. Experimental study in rats]

In order to approximate as close as possible genuine clinical conditions, the sciatic nerve of the rat was divided and then repaired after a delay of one or seven days either by application of a biological glue or by an epiperineural suture technique. The metabolic activity of the sciatic nerve Schwann cells - whether located in the distal or the proximal ends - and that of the (fast acting) white gastrocnemius and (slow acting) red soleus muscle were assessed using 32P-radiolabeled acid-soluble phosphates. Delayed repair, as judged by our biochemical criteria, was equivalent whatever method, biological glue or suture, was used. The frozen and lyophilized forms of the biological glue provided similar results.