Dynamics of pyruvate metabolism in Lactococcus lactis.

The pyruvate metabolism in the lactic acid bacterium Lactococcus lactis was studied in anaerobic cultures under transient conditions. During growth of L. lactis in continuous culture at high dilution rate, homolactic product formation was observed, i.e., lactate was produced as the major end product. At a lower dilution rate, the pyruvate metabolism shifted towards mixed acid-product formation where formate, acetate, and ethanol were produced in addition to lactate. The regulation of the shift in pyruvate metabolism was investigated by monitoring the dynamic behavior of L. lactis in continuous cultures subjected to step changes in dilution rate. Both shift-up and shift-down experiments were carried out, and these experiments showed that the enzyme pyruvate formate-lyase (PFL) plays a key role in the regulation of the shift. Pyruvate formate-lyase in vivo activity was regulated both at the level of gene expression and by allosteric modulation of the enzyme. A simple mathematical model was proposed to estimate the relative significance of the regulatory mechanisms involved.

Metabolic behavior of Lactococcus lactis MG1363 in microaerobic continuous cultivation at a low dilution rate.

Minute amounts of oxygen were supplied to a continuous cultivation of Lactococcus lactis subsp. cremoris MG1363 grown on a defined glucose-limited medium at a dilution rate of 0.1 h(-1). More than 80% of the carbon supplied with glucose ended up in fermentation products other than lactate. Addition of even minute amounts of oxygen increased the yield of biomass on glucose by more than 10% compared to that obtained under anaerobic conditions and had a dramatic impact on catabolic enzyme activities and hence on the distribution of carbon at the pyruvate branch point. Increasing aeration caused carbon dioxide and acetate to replace formate and ethanol as catabolic end products while hardly affecting the production of either acetoin or lactate. The negative impact of oxygen on the synthesis of pyruvate formate lyase was confirmed. Moreover, oxygen was shown to down regulate the protein level of alcohol dehydrogenase while increasing the enzyme activity levels of the pyruvate dehydrogenase complex, alpha-acetolactate synthase, and the NADH oxidases. Lactate dehydrogenase and glyceraldehyde dehydrogenase enzyme activity levels were unaffected by aeration.

Determination of the phosphorylated sugars of the Embden-Meyerhoff-Parnas pathway in Lactococcus lactis using a fast sampling technique and solid phase extraction.

An experimental procedure for the determination of intracellular concentrations of the phosphorylated sugars in the lactic acid bacterium Lactococcus lactis is presented. The first step of the procedure is a rapid sampling of a small volume of the growth medium into 60% (v/v) methanol precooled to -35 degrees C, bringing about a fast and complete stop of all metabolic activity. In contrast to yeast the metabolites leak out of the cells when these are brought into contact with methanol and are present in the medium and in the biomass after the quenching. A liquid-liquid extraction with chloroform at -25 degrees C ensures a total permeability of the cellular membrane towards the metabolites of interest as well as the inactivation of enzymes liable to alter their levels. The final step of the procedure consists in a solid phase extraction using columns with a high affinity for phosphorylated components. The internal standard was recovered to an extent of 85-95%.

Pen injected apomorphine against off phenomena in late Parkinson's disease: a double blind, placebo controlled study.

The effect, therapeutic dose range, and pharmacokinetics of apomorphine, given as subcutaneous injections by a single use pen, were evaluated in the treatment of off phenomena in 22 patients with idiopathic Parkinson's disease. At study entry a placebo controlled apomorphine test was performed, and apomorphine doses were then individually titrated (mean 3.4 (range 0.8-6.0) mg) and compared with placebo in a double blind cross over phase. With apomorphine compared with placebo the mean daily duration of off periods was reduced by 51% as assessed by the patients and by 58% as assessed by the staff. The severity of off periods was also significantly reduced. The effect was unchanged after a maintenance phase of eight weeks. At study termination 13 of 14 patients were able to inject themselves and 11 of 14 patients found that their feeling of freedom had increased. The most common adverse events were nausea, subcutaneous nodules, and increased frequency of involuntary movements. Pharmacokinetics were linear and did not change with repeat dosing. The tmax ranged from five to 45 minutes (16 patients). It is concluded that pen injected apomorphine is a valuable treatment for patients with advanced Parkinson's disease with on-off phenomena.

[Apomorphine in the treatment of Parkinson disease]. / Apomorfin i behandlingen af Parkinson's sygdom.

In later stages of the disease, patients with Parkinson's disease treated with levodopa may become severely disabled by pronounced and sudden motor fluctuations called "the on-off syndrome". In spite of optimal individual adjustment of doses and combinations, orally administered antiparkinson drugs are often not able to eliminate the off-conditions which may last from minutes to hours and sometimes are accompanied by dystonic pain. Apomorphine, a potent dopamine receptor agonist, administered subcutaneously as single injections or continuously by means of a pump, quickly passes on to striatal dopamine receptors. With suitable individually adjusted doses, a rapid, and in some cases, more stable anti-parkinson effect may be achieved. Peripheral side-effects can be avoided by concomitant treatment with domperidone. Nine levodopa treated patients with Parkinson's disease and severe on-off syndrome received apomorphine. Seven experienced considerable and long-term improvement of the disabling symptoms, and some patients reduction of levodopa and/or bromocriptine doses. Treatment with apomorphine should only be considered in patients whose on-conditions are not accompanied by pronounced dyskinesias and/or impairment of balance or to patients suffering from severe dystonic pain.

Survival of patients with amyotrophic lateral sclerosis in 2 Danish counties.

We investigated the survival of patients with amyotrophic lateral sclerosis (ALS) in a follow-up study of all patients hospitalized with the disease in 2 Danish counties during the period 1974 to 1986. There were 186 patients, with a mean age at diagnosis of 64.3 years. The median survival time was 12 months from diagnosis, the 3-year survival rate was 12%, and the 5-year survival rate 4%. (The corresponding figures from onset were 23 months, 26%, and 7%). Old age and bulbar findings at onset were negative prognostic factors. For each clinical category, the annual death rate remained constant throughout the observation period, indicating the effects of a steadily progressing degenerative disorder. We found no evidence of the existence of a separate variety of ALS, associated with long survival.

Incidence and prevalence of motor neuron disease in two Danish counties.

A total of 186 cases of motor neuron disease (MND) was identified in two Danish counties during the period 1974-1986. The average annual incidence rate was 1.4/100,000 population, and the male:female ratio of incidence rates was 1.5. Mean age at diagnosis was 64.3 +/- 10.0 years. The incidence rates increased significantly with advancing age and reached a maximum at age 60-79 years, followed by a nonsignificant decrease. The average point prevalence was 3.1/100,000 population. Bulbar symptoms were part of the initial symptoms in 65% of cases, and patients with bulbar onset were older than patients with spinal onset. Age- and sex-specific incidence rates indicated a marked male preponderance amongst the youngest patients, in contrast to a female preponderance in patients above 60 years with bulbar onset of MND. Familial MND accounted for 2.7% of cases.

CSF somatostatin in multiple sclerosis: reversible loss of diurnal oscillation in relapses.

CSF and venous blood were sampled hourly during 24 hours in 6 control subjects and in 12 patients with MS, 5 of whom were in stable phase and 7 in relapse. CSF somatostatin immunoreactivity was 166 +/- 5.3 (SFM) pg/ml in controls at noon and rose around midnight to 208 +/- 3.8 pg/ml, then decreased to basal levels at about 5 hours and exhibited another small peak 3 hours later. Almost identical patterns were found in patients with MS during stable phase. During relapse, CSF somatostatin was reduced to 99 +/- 9.2 pg/ml and showed no variation from this value. CSF albumin was similar in the three groups and exhibited no fluctuations. Diurnal patterns of serum growth hormone were similar and unrelated to the oscillations in CSF somatostatin, indicating that hypothalamic release was insignificant in the overall production and in variations. The observation that the CNS releases somatostatin at lower levels during relapse in MS and that these do not oscillate may suggest that the constant low contents represent passive spillover from somatostatin-containing neurons, while the undulating levels above them are representative of active, yet unknown neurophysiologic (eg, neurotransmitter) functions which become reversibly extinct in relapse.

Chronic paroxysmal hemicrania: continued remission of symptoms after discontinuation of indomethacin.

Discontinuation of indomethacin in chronic paroxysmal hemicrania (CPH) usually causes relapse of symptoms within a few days. A patient with characteristic symptoms of CPH is reported. The patient had daily attacks of unilateral headache accompanied by ipsilateral lacrimation and conjunctival injection, a frequency of attacks between four and fourteen per day, and never a headache-free day. He was treated with indomethacin, and all symptoms disappeared within 24 h. After three months indomethacin was discontinued. Six months after that the patient was still symptom-free.

Breast tumour. An unusual manifestation of a carcinoma of the stomach.

A 59-year-old woman presented with an infiltration in the left breast and a large mass of enlarged lymph nodes on the left side of the neck. Radiological and histological examinations showed that the breast involvement was a mastitis carcinomatosa secondary to a carcinoma of the stomach. A review of the literature revealed ten earlier cases of metastases to the breast from a primary carcinoma of the stomach. The cases are discussed especially concerning the way of tumour spread.

Acute effect of intravenous labetalol in the treatment of systemic arterial hypertension.

1 The acute anti-hypertensive effect of intravenously administered labetalol, a combined alpha- and beta-adrenoreceptor antagonist, has been assessed in a pilot study involving 17 hypertensive patients. 2 In 11 patients with mild to moderately severe hypertension, there was a decrease in mean arterial pressure (24 mmHg) after a single intravenous dose of 50 mg labetalol. The peak response occurred approximately 4 min after administration of the drug. 3 In six patients with severe hypertension, there was a reduction in mean arterial pressure of 19 mmHg, but this was achieved after a further 50-mg dose administered 30 min after the initial injection. 4 In neither group was there any clinically significant decrease in heart rate, and drug-related side-effects were insignificant. 5 Labetalol reduced the blood pressure when administered intravenously and thus merits further investigation as a treatment for acute hypertensive crises.