NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson's disease

Nicotinamide adenine dinucleotide (NAD) replenishment therapy using nicotinamide riboside (NR) shows promise for Parkinson's disease (PD) and other neurodegenerative disorders. However, the optimal dose of NR remains unknown, and doses exceeding 2000 mg daily have not been tested in humans. To evaluate the safety of high-dose NR therapy, we conducted a single-center, randomized, placebo-controlled, double-blind, phase I trial on 20 individuals with PD, randomized 1:1 on NR 1500 mg twice daily (n = 10) or placebo (n = 10) for four weeks. The trial was conducted at the Department of Neurology, Haukeland University Hospital, Bergen, Norway. The primary outcome was safety, defined as the frequency of moderate and severe adverse events. Secondary outcomes were tolerability defined as frequency of mild adverse events, change in the whole blood and urine NAD metabolome, and change in the clinical severity of PD, measured by MDS-UPDRS. All 20 participants completed the trial. The trial met all prespecified outcomes. NR therapy was well tolerated with no moderate or severe adverse events, and no significant difference in mild adverse events. NR therapy was associated with clinical improvement of total MDS-UPDRS scores. However, this change was also associated with a shorter interval since the last levodopa dose. NR greatly augmented the blood NAD metabolome with up to 5-fold increase in blood NAD+ levels. While NR-recipients exhibited a slight initial rise in serum homocysteine levels, the integrity of the methyl donor pool remained intact. Our results support extending the dose range of NR in phase II clinical trials to 3000 mg per day, with appropriate safety monitoring. Clinicaltrials.gov identifier: NCT05344404.

Distigmine bromide induced acute psychotic disorder in a patient with multiple sclerosis

A female patient with multiple sclerosis (MS) suffered from an acute psychotic disorder after taking distigmine bromide for detrusor dysfunction. She showed a dramatic relief of her symptoms after the medication, distigmine bromide, was stopped. Distigmine is not supposed to penetrate the blood-brain barrier (BBB). However, in MS patients a leakage of the BBB could be hypothesized.

[Bowel obstruction-induced cholinergic crisis with progressive respiratory failure following distigmine bromide treatment]

A 54-year-old female experienced rapid respiratory failure while being transported in an ambulance to our emergency department for evaluation and management of constipation and abdominal pain. The patient was on treatment with distigmine bromide for postoperative urination disorder and magnesium oxide for constipation. Increased salivary secretions, diminished respiratory excursion, type 2 respiratory failure (PaCO2 : 65 mmHg), low serum cholinesterase, and hypermagnesemia were detected. Imaging studies revealed that the patient had bilateral aspiration pneumonia, fecal impaction in the rectum, and a distended colon causing ileus. The patient was mechanically ventilated and was weaned off the ventilator on day 3. Therapeutic drug monitoring after discharge revealed that the serum level of distigmine bromide on admission was markedly elevated (377.8 ng/mL vs. the normal therapeutic level of 5-10 ng/mL). Distigmine bromide induced a cholinergic crisis with a resultant increase in airway secretions and respiratory failure. In this particular case, orally administered distigmine bromide was excessively absorbed because of prolonged intestinal transit time secondary to fecal impaction and sluggish bowel movement; this caused a cholinergic crisis and hypermagnesemia contributing to respiratory failure. Clinicians should be aware that bowel obstruction in a patient treated with distigmine bromide can increase the risk of a cholinergic crisis.

HI-6 oxime (an acetylcholinesterase reactivator): blood plasma pharmacokinetics and organ distribution in experimental pigs

OBJECTIVES

Oxime HI-6 DMS (dimethanesulfonate) is an asymmetric bis-pyridinium aldoxime and essential acetylcholinesterase (AChE) reactivator. The high effectiveness is due to its wide spectrum of therapeutic activity against different structures of nerve agents. Aim of this study was to compare plasma time profiles and tissue distribution (to delimitation of potential toxicity risks) after its intramuscular (i.m.) and intragastric (i.g.) administration to experimental pigs.

METHODS

The study entered female Landrace pigs (Sus scrofa f. domestica), 4-5 months old animals, 29 ± 3.2 kg of body weight. Before the HI-6 DMS administration (i.m. injection or i.g. using a gastric tube), vena auricularis was cannulated (under general anaesthesia) for collection of blood samples. The tissue distribution study was carried out at expected t-max. Concentrations of HI-6 DMS in blood plasma and other tissue samples were detected by means of HPLC method.

RESULTS

Fast absorption after i.m. administration, relatively slow absorption and no even elimination after i.g. administration were found. Tissue distribution showed low accumulation in the liver, but a higher content in the kidneys and high concentrations in the brain and gastrointestinal wall.

CONCLUSIONS

Plasma time profiles after i.g. administration has a prolonged pharmacokinetics. Tissue distribution study showed potential side effects to the stomach due to a higher accumulation of HI-6 in this tissue after i.g. administration but not after a standard i.m. administration. Higher content of HI-6 in the kidneys after i.m. administration suggests the main way of the oxime elimination.

[Acute respiratory failure associated with cholinergic crisis: report of five cases and review of the literature]

Distigmine bromide is a cholinesterase inhibitor widely used for the treatment of hypotonic neurogenic bladder. However, this drug is also known to cause cholinergic crisis, a rare but serious adverse reaction. Cholinergic crisis is an excessive amount of acetylcholine due to the systemic inhibition of cholinesterase activity, characterized by parasympathetic symptoms such as sweating, salivation, miosis, bradycardia, diarrhea and circulatory and respiratory failure. The incidence of cholinergic crisis has been estimated at approximately 0.2%, and the majority of the patients are elderly with underlying conditions such as cerebrovascular disease. Since 2004, we have encountered 5 cases of acute respiratory failure associated with cholinergic crisis induced by the administration of a normal oral dose of distigmine. We present these cases here and review an additional 23 cases from the literature in Japan. In these 28 cases, mechanical ventilation was required for 57%, with a mean duration of 5.1 days and a mortality rate of 11%. Pneumonia was observed in half of the cases in the acute phase, and relapse due to the readministration of distigmine was reported in 20% of cases. It is important to remember that cholinergic crisis in the elderly is often misdiagnosed and is occasionally treated as simple aspiration pneumonia.

Novel nontoxic mitochondrial probe for confocal fluorescence microscopy

We propose a 2,5-Bis[1-(4-N-methylpyridinium)ethen-2-yl)]-N-methylpyrrole ditriflate (PEPEP) as a novel nontoxic, nonpotentiometric mitochondrial probe for confocal fluorescence microscopy. PEPEP is a representative chromophore of a large family of heterocyclic fluorescent dyes that show fluorescence emission in aqueous media and great DNA affinity. We check its cytotoxicity and intracellular localization in mammalian and yeast cell cultures. We demonstrate that PEPEP is a very efficient dye for fluorescence confocal microscopy and a valuable alternative to the most frequently used mitochondrial stains.

Potent antitumor activity of a novel cationic pyridinium-ceramide alone or in combination with gemcitabine against human head and neck squamous cell carcinomas in vitro and in vivo

In this study, a cationic water-soluble ceramide analog L-threo-C6-pyridinium-ceramide-bromide (L-t-C6-Pyr-Cer), which exhibits high solubility and bioavailability, inhibited the growth of various human head and neck squamous cell carcinoma (HNSCC) cell lines at low IC50 concentrations, independent of their p53 status. Consistent with its design to target negatively charged intracellular compartments, L-t-C6-Pyr-Cer accumulated mainly in mitochondria-, and nuclei-enriched fractions upon treatment of human UM-SCC-22A cells [human squamous cell carcinoma (SCC) of the hypopharynx] at 1 to 6 h. In addition to its growth-inhibitory function as a single agent, the supra-additive interaction of L-t-C6-Pyr-Cer with gemcitabine (GMZ), a chemotherapeutic agent used in HNSCC, was determined using isobologram studies. Then, the effects of this ceramide, alone or in combination with GMZ, on the growth of UM-SCC-22A xenografts in SCID mice was assessed following the determination of preclinical parameters, such as maximum tolerated dose, clearance from the blood, and bioaccumulation. Results demonstrated that treatment with L-t-C6-Pyr-Cer in combination with GMZ significantly prevented the growth of HNSCC tumors in vivo. The therapeutic efficacy of L-t-C6-Pyr-Cer/GMZ combination against HNSCC tumors was approximately 2.5-fold better than that of the combination of 5-fluorouracil/cis-platin. In addition, liquid chromatography/mass spectroscopy analysis showed that the levels of L-t-C6-Pyr-Cer in HNSCC tumors were significantly higher than its levels in the liver and intestines; interestingly, the combination with GMZ increased the sustained accumulation of this ceramide by approximately 40%. Moreover, treatment with L-t-C6-Pyr-Cer/GMZ combination resulted in a significant inhibition of telomerase activity and decrease in telomere length in vivo, which are among downstream targets of ceramide.

[Distigmine bromide induced Parkinsonism. A case report]

A 74-year-old man became unable to walk two days following the initiation of administration of oral distigmine bromide, 10 mg per day, for his constipation. Neurological examination revealed bradykinesia, rigidity and fine postural tremor without laterality. T2 weighted MRI showed mild front-temporal atrophy and multiple hyperintensities in both deep white matters. His symptoms fully improved one week after discontinuance of distigmine bromide. This is the first case report of distigmine bromide induced Parkinsonism.

[Cholinergic crisis following administration of distigmine bromide: a case report]

The long-acting anticholinesterase, distigmine bromide (Ubretid), is widely used for the treatment of underactive neurogenic bladder. Therefore, we emphasize its hazardable side-effect of cholinergic crisis. A 78-year-old man with duodenal ulcer complained of nocturia, and was administered distigmine bromide 10 mg daily under the diagnosis of mild benign prostatic hypertrophy with underactive neurogenic bladder. It seemed that administration slightly improved his symptom but he developed bradycardia, dyspnea and drowsiness suddenly on the 4th day. Blood examination revealed extremely low cholinesterase in his serum, suggesting distigmine bromide intoxication. He was treated intensively with several intravenous injections of atropine, high-concentration oxygen and transfusion of fresh frozen plasma. Nevertheless, his condition did not recover, resulting in death of "cholinergic crisis" on the 6th day.

Effect of a platelet-activating factor receptor antagonist, E5880, on cerebral vasospasm after aneurysmal subarachnoid hemorrhage--open clinical trial to investigate efficacy and safety

The efficacy and safety of a new platelet-activating factor receptor antagonist, E5880, were investigated for preventing cerebral vasospasm after subarachnoid hemorrhage (SAH) in 71 patients with SAH who underwent surgery for ruptured aneurysms within 3 days. Intravenous E5880 administration (300 micrograms or 1200 micrograms twice daily) was begun within 4 days and continued for 14 days. The incidence of symptomatic vasospasm, low-density area on computed tomography, and angiographic vasospasm was lower than in placebo groups in previous studies. Clinical outcome was favorable compared with previous studies. No clinically important adverse events were observed. These results suggest that E5880 is safe and effective in the treatment of patients with cerebral vasospasm due to SAH.

Decreased organ failure in patients with severe SIRS and septic shock treated with the platelet-activating factor antagonist TCV-309: a prospective, multicenter, double-blind, randomized phase II trial. TCV-309 Septic Shock Study Group

Sepsis and organ failure remain the main cause of death on the ICU. Sepsis is characterized by a severe inflammatory response, in which platelet-activating factor (PAF) is considered to play an important role. This study investigated whether treatment with the PAF-antagonist TCV-309 reduces morbidity and mortality in patients with septic shock. The study was conducted as a double-blind, randomized, placebo controlled multicenter study. The included patients had to fulfill the SIRS criteria with a clinical suspicion of infection, an admission APACHE II score greater than 15, and shock, defined as a mean arterial pressure <70 mmHg and/or a decrease > or =40 mmHg despite adequate fluid resuscitation. Patients received 1.0 mg/kg TCV-309 or placebo, twice daily, intravenously during 14 days. The prospectively set goals were MOF score, recovery from shock, mortality, and assessment of the safety of the medication. A total of 98 patients were included of which 97 were analyzed on an intention-to-treat basis. The overall survival at day 56 of TCV-309 treated patients was similar compared to placebo treated patients (51.0% vs. 41.7%, P = 0.47). In contrast, the mean percentage of failed organs per patient present after 14 days in the TCV-309 treated patients was significantly lower compared to the placebo treated patients (11.9% vs. 25.1%, P = 0.04), leading to a reduced need for vasopressors, dialysis, and ventilatory support. Furthermore, the mean APACHE-II score during treatment with TCV-309 was significantly lower and the number of patients recovered from shock after day 14 was significantly higher in the TCV-309 treated patient group (2/32 vs. 9/29, P = 0.01). The number of adverse events was not significantly different between the TCV-309 and placebo treated patients. TCV-309 did not change overall mortality of septic shock, however a substantial reduction in organ dysfunction and morbidity, frequently associated with septic shock was achieved, without significant adverse events.

Absolute bioavailability, pharmacokinetics, renal and biliary clearance of distigmine after a single oral dose in comparison to i.v. administration of 14C-distigmine-bromide in healthy volunteers

AIM

The aim of the study was to determine the absolute bioavailability and pharmacokinetics after a single dose oral administration in comparison to i.v. administration of 14C-labelled distigmine-bromide (14C-Ubretid) in healthy male volunteers.

RESULTS

After the intravenous administration, distigmine is eliminated from the body by renal excretion (85%), and for a small fraction by biliary excretion in the feces (4%). This situation is reversed after an oral administration, where 6.5% of the dose is recovered from the urine and 88% from the feces. This means that distigmine after oral administration is hardly absorbed, the calculated bioavailability is 4.65%.

CONCLUSION

The mean absorption time (MAT) after oral administration was 10 h, influencing the t(1/2alpha) (1.4 vs 4.5 h) and the t(1/2beta) (60 vs 70 h) to higher values than after the i.v. administration (p < 0.05).

[Relationship between cholinergic symptoms caused by distigmine and the activities of serum AChE and BChE]

Distigmine is widely used for the treatment of dysuria, which is caused by various types of psychotropic medications. Distigmine, however, is also known to induce adverse cholinergic effects, such as diarrhea and salivation, with a decreased level of serum cholinesterase. We evaluated the possibility of using serum acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) as specific clinical markers for the adverse cholinergic effects of distigmine. Of the twelve patients treated with distigmine for dysuria caused by psychotropic drugs six patients presented both adverse cholinergic effects and decreased levels of serum AChE and BChE. The other six presented neither of these changes. This study suggests that the values of serum AChE and BChE may be useful markers for the manifestation of adverse cholinergic effects caused by distigmine.

Influence of dopaminergic medication on automatic postural responses and balance impairment in Parkinson's disease

It is still unclear why balance impairment in Parkinson's disease (PD) often responds insufficiently to dopaminergic medication. We have studied this issue in 23 patients with idiopathic PD and 24 healthy controls. Our specific purposes were (a) to investigate the contribution of abnormal automatic postural responses to balance impairment in PD and (b) to assess the influence of dopaminergic medication on abnormal automatic postural responses and balance impairment. Standing subjects received 4 degrees "toe-up" rotational perturbations of a supporting forceplate. We bilaterally recorded posturally destabilizing medium latency (ML) responses from the stretched gastrocnemius muscles and functionally corrective long latency (LL) responses from the shortened tibialis anterior (TA) muscles. We also assessed changes in the center of foot pressure (CFP) and the center of gravity (COG). All patients were tested in the "off" and "on" phases. All controls were tested and retested after 1 h. During the off phase, we found enlarged ML amplitudes and diminished LL amplitudes in patients, together with a markedly increased posterior displacement of the COG. The abnormal ML and LL responses were partially responsible for the increased body sway in patients because the initial forward (destabilizing) displacement of the CFP was increased, while the subsequent backward displacement of the CFP (a measure of the corrective braking action of LL responses) was delayed. Abnormal late automatic or possibly more voluntary postural corrections also contributed substantially to the increased body sway. During the on phase, ML amplitudes were reduced in patients but remained increased compared with controls. LL amplitudes no longer differed between both groups due to a modest, possibly dopamine-related increase in patients and a simultaneous decrease in controls. The abnormal CFP displacement was only partially improved by dopaminergic medication. The later postural corrections were not improved at all. Consequently, the increased posterior COG displacement was not ameliorated during the on phase. We conclude that (a) a combination of abnormal automatic and perhaps more voluntary postural corrections contributes to increased body sway in PD and (b) dopaminergic medication fails to improve balance impairment in PD because early automatic postural responses are only partially corrected, while later occurring postural corrections are not improved at all. These electrophysiological results support clinical observations and suggest that nondopaminergic lesions play a significant role in the pathophysiology of postural abnormalities in PD.

Cholinergic crisis following treatment of postoperative urinary retention with distigmine bromide

Distigmine bromide is a long-acting anticholinesterase, available for the treatment of postoperative urinary retention. Its effectiveness is unproven and administration may be hazardous. We describe a case in which oral distigmine bromide was used for postoperative retention, resulting in a potentially life-threatening 'cholinergic crisis'. We review the literature and conclude that the use of oral distigmine bromide in postoperative urinary retention is not justified.

Identification of a pyridinium metabolite in human urine following a single oral dose of 1-[2-[bis[4-(trifluoromethyl)phenyl]methoxy]ethyl]- 1,2,5,6-tetrahydro-3-pyridinecarboxylic acid monohydrochloride, a gamma-aminobutyric acid uptake inhibitor

Single-dose administration of 50 mg of 1-[2-[bis[4- (trifluoromethyl)phenyl]methoxy]ethyl]-1,2,5,6-tetrahydro-3- pyridinecarboxylic acid monohydrochloride resulted in temporary neurological and psychological symptoms in two subjects. Because of the nature of adverse effects, urine from a subject who received CI-966 orally was extracted to investigate the metabolism of CI-966 in man. An unknown urinary component was identified as a pyridinium metabolite of CI-966 based on HPLC-MS and 1H and 19F NMR. Structural confirmation was achieved by chromatographic and spectroscopic comparisons to a reference standard. In several in vitro screens and preclinical studies, the pyridinium metabolite appears to possess minimal pharmacological activity.

Oral forms of the oxime HI-6: a study of pharmacokinetics and tolerance after administration to healthy volunteers

New pharmaceutical formulations of the oxime HI-6 as sustained-release and conventional tablets were studied in healthy volunteers. Twenty-six subjects, divided into 3 groups, received 3784 mg or 7568 mg doses of HI-6 conventional tablets or 4027 mg of the oxime in the form of sustained-release tablets. Peak plasma concentrations of HI-6 were reached within 0.6 h (10.2 mumol/l) and 1.6 h (21.4 mumol/l) following the ingestion of conventional tablets. Elimination half-lives were similar (1.7 h and 1.3 h) and the respective urinary recoveries amounted to 3.2% and 2.9%. After the administration of sustained-release tablets of HI-6, maximal concentration (8.8 mumol/l) was attained in 2.2 h, elimination half-life was 1.9 h and 4.2% of the dose was excreted unchanged in urine. Undesirable side effects were not reported by the subjects or revealed by clinical or laboratory tests. The results indicate low bioavailability of the oral formulations of HI-6 in man.

[Anaphylactic shock after sucking on a throat lozenge]

A few minutes after sucking a lozenge for a sore throat a 68-year-old man developed an anaphylactic shock. At a heart rate of 110/min there was no palpable blood pressure. A red confluent exanthem, predominantly of the trunk, was noted. After brief intensive-care treatment the patient was completely well again and diagnostic tests for allergy were performed. The prick test for the 14 individual ingredients of the throat lozenge produced massive reddening and urticaria on the test arm with carbowax, a polyethylene glycol which serves as a vehicle in the remedy and does not have to be listed. Later there were an urge to cough and urticaria all over the trunk. There was no systemic reaction. Neither specific IgE antibodies nor any complement-consuming reaction could be demonstrated. Thus the precipitating mechanism remains unexplained.

The use and effects of vital fluorescent dyes: observation of motor nerve terminals and satellite cells in living frog muscles

Several different fluorescent mitochondrial dyes were tested as vital stains for motor nerve terminals and other cells in frog skeletal muscles. It was found that 3,3' diethyloxadicarbocyanine iodide and 4-(4-diethylaminostyryl)-N-methylpyridinium iodide were most useful. Both dyes labelled motor nerve terminals with high reliability. Electrophysiological and morphological control experiments showed that these dyes could be used to repeatedly observe neuromuscular junctions in living animals without affecting synaptic growth or remodelling. The importance of appropriate controls was emphasized by the finding that illumination, if excessively intense or prolonged, can cause physiological and structural damage to nerve terminals. Additional observations indicated that these dyes may be useful for determining the mitochondrial content, and therefore oxidative capacity, of living muscle fibres. It was also found that the fluorescent dyes labelled cells identified as muscle satellite cells, and that these myoblast precursors could be visualized in fixed whole mounts with a nitroblue tetrazolium stain. Both methods were used to study reactive cells that were closely associated with muscle fibres in lesioned muscles. Mitochondrial dyes also labelled the microvasculature, associated axons and other cells.

Histopathological changes in gastrocnemius muscles of rabbits injected with HI-6 in saline

The gastrocnemius muscles of rabbits were injected with HI-6 in saline. Macroscopic and histopathological examinations of injection sites and regional lymph nodes revealed that HI-6 in saline produced muscle necrosis. Macroscopic examinations of muscles injected with a low dose of HI-6 (50 mg/kg) showed no lesions on Day 7. However, histopathological examinations disclosed lesions on some animals but with evidence of healing processes by Day 7; lesions disappeared by Day 14. Further macroscopic and histopathological examinations revealed that lesions associated with the high dose (200 mg/kg) were still prominent on Day 14 but with evidence of healing. Similar lesions seen in muscles injected with saline were significantly less persistent than those associated with HI-6.

Side effects of therapeutic drugs against organophosphate poisoning

The possible side effects of therapeutic drugs against organophosphate poisoning were investigated. First, dose-effect curves were obtained with atropine sulphate (AS), P2S, obidoxime, aprophen, N-methylatropine nitrate and HI-6. The first three drugs are currently used in the therapy of organophosphate poisoning, the others are potentially useful candidates. Automated tests measuring open field behavior, motor coordination and shuttlebox performance, as well as neurophysiological techniques such as the quantified EEG (qEEG) and visual evoked responses were used. The sign-free doses of these compounds were determined; it appeared that open field behavior and the qEEG were the most sensitive methods for these drugs. Subsequently, these two methods were used to investigate the effects of the combinations of AS and P2S, AS and obidoxime or AS and HI-6, each compound given in a sign-free dose. Synergistic or additive effects were found with the combination of AS and P2S, which were smaller with the combination of AS and obidoxime and absent with the combination of AS and HI-6. These results indicate that the untimely use (false alarm, panic) of the current drug combinations may cause undesirable side effects.

Effect of fazadinium on respiratory functions and its correlation with neuromuscular transmission in children

Effects of fazadinium in doses of 0.75, 1.0 and 1.25 mg/kg and pancuronium 0.1 mg/kg on respiratory functions (tidal volume, minute volume and inspiratory force) and correlation between respiratory functions and neuromuscular transmission were evaluated in 64 children aged 6 months to 12 years undergoing various types of elective surgery. Neuromuscular transmission was evaluated by a digitial EMG system using train-of-four stimuli calculating T1 and T4 ratios. Time to apnea, duration of apnea, time and mode of recovery of respiratory functions and neuromuscular transmission when spontaneous respiration started and recovered completely were recorded. The speed, depth and duration of effect of fazadinium on respiration were dose related, 0.75 mg/kg being inadequate to produce apnea in the majority of cases. Duration of apnea increased significantly with increasing dosage (13 +/- 2, 17 +/- 2, 23 +/- 2 minutes respectively). At the end of surgery respiratory measurements reached control values either spontaneously or after reversal. Spontaneous recovery took significantly longer times (34 +/- 3, 51 +/- 5, 95 +/- 10 minutes respectively) depending on dosage. In the remaining patients recovery was complete within five minutes after reversal. Pancuronium could be placed between 1.0 and 1.25 mg/kg fazadinium regarding aspects other than speed of onset of effect. Neuromuscular transmission was still markedly depressed when spontaneous respiration started (T4/T1 of 7-24%) and recovered (T4/T1 of 35-57%) indicating that when recovery from neuromuscular blockade is to be evaluated clinically, adequancy of ventilation by itself should not be taken as a sign of recovery from the effect of relaxant.

[Effect of pyrithiamine on rat sciatic nerve. (II) Morphological changes during the last stages of thiamine deficiency (author's transl)]

We observed under light and electron microscopes morphological changes in the rat sciatic nerve during the last stages of a thiamine deficient state as induced by pyrithiamine (PT: 50 microgram/100g X 11 days) and thiamine deficient diet (TDD), in which rats experienced severe tetanic convulsions. Experiments were undertaken with normal control, PT (PT treated rats) and PTD (PT treated rats fed a TDD) groups. Grossly, 4 out of 9 rats in the PTD group had severe tetanic convulsions on the 12th day and there were no neurologic signs in the PT group. Microscopically, many of the myelinated axons in the animals in the PT group showed shrinkage with myelin ovoids and folds, but in the PTD group, there was swelling as well as shrinkage. Despite the difference in general-symptoms between the PT and the PTD groups, axonal degeneration in the both groups, as determined electron microscopically was almost to the same degree and the convulsed rats in the PTD group showed the severest changes in the myelin sheath. These ultrastructural changes included swelling or vacuolation of Schwann cells, axonal degeneration with the appearance of a myelin like structure, collection of neuro-tubules or vacuoles, invasion of Schwann cell or/and myelin fragments into the periaxonal space, and active phagocytosis by the macrophages. These results suggest that PT directly affects the nervous system and that the dysfunction of the sciatic nerve following PT-induced thiamine deficiency originates from the central nervous system.

[Effect of pyrithiamine on rat sciatic nerve. (I) Morphological changes during the early stage of thiamine deficiency (author's transl)]

We observed under light and electron microscopes morphological changes in the rat sciatic nerve during the early stages of a thiamine deficient state as induced by a pyrithiamine (PT: 50 microgram/100g X 6 days) and thiamine deficient diet (TDD). We simultaneously determined thiamine levels in the whole sciatic nerve of rats. Experiments were undertaken with normal control, TDD (rats fed a TDD), PT (PT treated rats) and PTD (PT treated rats fed a TDD) groups. Microscopically, there were numerous shrunken myelinated axons with myelin ovoids of folds in the PT group and many swollen ones in the PTD group. Electron microscopically, we found more advanced lesions in the PTD group than in the other groups. These ultrastructural changes were swelling of Schwann cells, enlarged rough-surfaced endoplasmic reticulum, axonal degeneration with shrinkage, loss of organelle or abnormal myelin sheath, and proliferation of fibroblasts. The thiamine level in the PTD group decreased to 18 approximately 30% that of control in proportion to the morphological changes. On the other hand, the thiamine level in the PT group (55 approximately 61%) decreased slightly more than that of the TDD group (50 approximately 56%), but changes in morphology were vice versa. These results suggest that the morphological changes in the sciatic nerve caused by PT-induced thiamine deficiency differs from changes seen in cases of dying-back neuropathy caused by TDD-induced deficiency, and that PT itself directly affects the nervous system

[Treatment of drug-induced dryness of mouth in psychiatric pateints--a controlled comparative study (author's transl)]

The present study examined the effects of various substances on salivary secretion in 25 psychiatric inpatients suffering from depression or schizoprenic disorders. It is well known that tricyclic neuroleptics and anti-depressants lower the rate of salivary excretion and lead to hyposalivation and a dry mouth. The following methods were studied on their effect to compensate hyposalivation: Distigminbromid, sweets, Glandosane, a new synthetic saliva, and water which was gustatory adopted. Salivary flow was measured according to Matzker (7). Subjective feelings of thirst and mouth dryness were recorded by selfconstructed tests. Only Glandosane and Distigminbromid compensated mouth dryness. The recorded amount of salivary flow was within the range of normal controls. There were no significant correlations between the subjective test answers and the objective measurement of salivary rate. Improvement of depression by application of Glandosane could not be observed. Patients treated with Glandosane felt most comfortable whereas in those treated with Distigminbromid side effects as digestive disorders, urinary disorders and changes in perspiration were observed.

Adverse reactions following fazadinium-thiopentone induction

Three cases of hypersensitivity to an anaesthetic induction with fazadinium and thiopentone are described. One reaction was fatal. Two patients had documented and the third presumptive previous exposure to thiopentone, and all had a history of allergy (skin rash) to penicillin. None of the patients had received fazadinium before. The possibility that fazadinium contributed to the severity of the reactions is conjectural.

[Hemodynamic effects of a new antidepolarizing agent: fazadinium bromide]

Studies concerning the hemodynamic effects of this new antidepolarizing agent are scarce and difficult to interpret because of drug interactions, and of an accentuation of vagal tonus related to the use of morphinomimetic analgesics. For a better approach of the effects proper to fazadinium, we have tried to perform a study freed, to a maximum, from any drug interference. We studied the hemodynamic effects to a single dose of 1 mg.kg-1 of fazadinium bromide during 35 minutes in coronary patients normal hemodynamically or rhythmically, non-premedicated, ventilated with 50 p. 100 nitrous oxide in oxygen, and bebore any surgical procedure. All hemodynamic modifications are moderate and maximal 10 minutes after injection. The stroke index decreases 16 p. 100, heart rate increases 6 p. 100 and cardiac index falls 10 p. 100. Total peripheral resistance remains unchanged and mean arterial pressure drops 10 p. 100. Finally pulmonary wedge pressure decreases slightly. None of these modifications are statistically significant. One may, therefore, conclude that fazadinium tolerance, when the drug is freed from any drug interference, in coronary patients normal hemodynamically and free from rhythm disorders is excellent from a hemodynamic and rhythmic point of view. However, other isolated observations of hypovolemic subjects, or patients with atrial fibrillation receiving fazadinium and studied hemodynamically suggest a poorer tolerance in these cases.

Fazadinium in anaesthesia

The clinical use of the neuromuscular blocking agent fazadinium was investigated in a survey of 500 patients. Rapid conditions for tracheal intubation followed by excellent relaxation and easy antagonism were obtained. It is suggested that these findings commend it as an alternative to suxamethonium. Tachycardia appeared to be the only disadvantage associated with its use.

The use of AH8165 for Caesarian section

The use of AH8165, a new non-depolarising relaxant, for Caesarian section is reported. The rapidity of action and the absence of significant placental transfer of the drug were confirmed. AH8165 has a definite place in obstetric anaesthesia.