Determination of the prognostic value of cyclin D1 overexpression in breast cancer

Cyclin D1 plays a critical role in the timing of the initiation of DNA synthesis in the normal cell cycle of mammalian cells. Deregulated expression of this protein has been seen in a variety of tumours either as a result of gene amplification or chromosomal translocation, in breast cancer and B cell malignancies respectively. In order to determine the role this putative oncoprotein plays in breast cancer, we have applied a new monoclonal antibody, recently produced in our laboratory, in an immunohistochemical study of 93 primary breast carcinomas. We show that approximately 28% of the cases displayed enhanced expression of the cyclin D1 protein. Furthermore, either cyclin D1, cyclin D3, or both, were expressed in 69% of cases, suggesting that overexpression of any one member of this family may relieve cancer cells of their mitogenic stimulatory requirement. In addition, we show that those patients whose breast cancers co-express cyclin D1 with either epidermal growth factor receptor (EGFR) or the retinoblastoma protein (pRB) have a significantly poorer prognosis in comparison to those expressing cyclin D1 alone. Our observations indicate that, in a subset of breast cancers, aberrant cyclin D1 expression is a contributory factor to tumorigenesis and in association with EGFR or pRB expression, identify those tumours which may require more aggressive therapy.

Reliability of auditory brainstem responses from sequenced high-frequency (> or = 8 kHz) tonebursts

An auditory brainstem response method is described for evoking responses to 4 high-frequency (8, 10, 12 and 14 kHz) tonebursts in the same amount of time normally required to obtain responses to single tonebursts. Reliability of responses to high-frequency toneburst stimuli presented in the conventional manner (one at a time) has been previously documented. In the present study, high-frequency tonebursts were presented to 20 normal-hearing subjects singly and in a 4-stimulus sequence. The reliability of resulting responses did not differ significantly between single- and multiple-stimulus test conditions. It is concluded that this sequenced-stimulus concept could be developed for use in serial monitoring of individuals receiving ototoxic agents as well as being broadly applicable to clinical situations in which patients cannot or will not respond voluntarily.

Prevention of drug absorption in simulated theophylline overdose

1. The effects of emesis, gastric lavage and oral activated charcoal on theophylline absorption were compared in healthy volunteers. 2. One of four regimes (ipecacuanha-induced emesis, gastric lavage, oral activated charcoal and no treatment) was randomly chosen one hour after a simulated overdose with sustained-release theophylline on four separate occasions in twelve healthy volunteers. 3. Syrup of ipecacuanha produced emesis in all twelve volunteers but only seven vomited any tablets. Gastric lavage yielded tablets in only one volunteer. 4. The mean systemic availabilities (areas under the concentration-time curves relative to control) of theophylline for ipecacuanha-induced emesis, gastric lavage and charcoal, were 107.1%, 101.1% and 16.9%, respectively. 5. Oral activated charcoal was thus highly effective, while gastric lavage and emesis were ineffective in preventing theophylline absorption. Activated charcoal is potentially the most effective first-line treatment for acute overdosage with sustained-release theophylline tablets.

Relative mortality from overdose of antidepressants

OBJECTIVE

To compare the fatal toxicities of antidepressant drugs in 1987-92.

DESIGN

Retrospective epidemiological review of prescription data of the Department of Health, Scottish Office Home and Health Department, and Welsh Health Common Services Authority (excluding data from most private general practices and most hospitals), and mortality data from the Office of Population Censuses and Surveys and General Register Office in Scotland.

SETTING

General practice, England, Scotland, and Wales.

MAIN OUTCOME MEASURES

Deaths per million prescriptions and deaths per defined daily dose.

RESULTS

81.6% (1310/1606) of deaths from antidepressant overdose were due to two drugs, amitriptyline and dothiepin. The overall average of deaths per million prescriptions was 30.1. The overall rate for tricyclic drugs was 34.14 (95% confidence interval 32.47 to 38.86; P < 0.001), monoamine oxidase inhibitors 13.48 (6.93 to 22.19; P < 0.001), atypical drugs 6.19 (4.04 to 8.80; P < 0.001), and selective serotonin reuptake inhibitors 2.02 (0.64 to 4.17; P < 0.001). The numbers of deaths per million prescriptions of amoxapine, dothiepin, and amitriptyline were significantly higher than expected, while nine drugs had a significantly lower number of deaths per million prescriptions than expected. Analysis of deaths per defined daily dose showed a similar pattern.

CONCLUSIONS

Safety in overdose should be considered in risk-benefit and cost-benefit considerations of antidepressants. A switch in prescribing, from drugs with a high number of deaths per million prescriptions to drugs with a low number, could reduce the numbers of deaths from overdose. Although this form of suicide prevention can be implemented easily and immediately, its introduction needs to be considered against the higher costs of some of the newer drugs.

Response to glucagon in imipramine overdose

A 25-year-old woman, severely hypotensive following a massive imipramine overdose, had an immediate and sustained rise in blood pressure following intravenous glucagon (10 mg bolus followed by an infusion of 10 mg over 6 h). The QRS interval on the electrocardiogram shortened from 129 to 89 msec. Glucagon should be considered in hypotension following tricyclic antidepressant overdose; it may also be antiarrhythmic.

Prevention of drug absorption in simulated theophylline overdose

To assess the effectiveness of oral activated charcoal and catharsis in preventing theophylline absorption, 12 healthy subjects, aged 20-35 years, received 3 x 200 mg sustained-release theophylline tablets and 16 radio-opaque placebo tablets on six occasions. On each occasion, they received either no treatment (control) or one of five treatments. Treatments were a) oral activated charcoal (Carbomix): 50 g at 1 h, 25 g at 5 h and 9 h; b) sorbitol 70%: 150 mL at 1 h; c) activated charcoal: 50 g at 6 h, 25 g at 10 h and 14 h; d) sorbitol 70%: 150 mL at 6 h; e) charcoal commencing at 6 h plus sorbitol at 6 h (i.e. a combination of treatments c and d). Plasma theophylline concentrations were measured and all stools collected over 36 h to assess placebo tablet recovery by radiography. Charcoal administration at 1 h was 91.2% effective in preventing theophylline absorption and at 6 h was 57.3% effective, while combined charcoal and catharsis at 6 h was 63.3% effective. Sorbitol-induced catharsis at 1 h and 6 h did not reduce theophylline absorption despite greater tablet recovery. Oral activated charcoal may be the most effective treatment for sustained-release theophylline overdose, with maximum benefit when administered soon after an overdose, though later administration might still be of value. Sorbitol catharsis is of no benefit either alone or in combination with charcoal.

High-frequency toneburst-evoked ABR latency-intensity functions in sensorineural hearing-impaired humans

The latency-intensity functions (LIFs) of ABRs elicited by high-frequency (8, 10, 12, and 14 kHz) toneburst stimuli were evaluated in 20 subjects with confirmed 'moderate' high-frequency sensorineural hearing loss. Wave V results from clicks and tonebursts revealed all intra- and intersession data to be reliable (p > 0.05). Linear regression curves were highly significant (p < or = 0.0001), indicating linear relationships for all stimuli analyzed. Comparisons between the linear regression curves from a previously reported normal-hearing subject group and this sensorineural hearing-impaired group showed no significant differences. This study demonstrated that tonebursts at 8, 10, and 12 kHz evoked ABRs which decreased in latency as a function of increasing intensity and that these LIFs were consistent and orderly (14 kHz was not determinable). These results will contribute information to facilitate the establishment of change criteria used to predict change in hearing during treatment with ototoxic medications.

Relationships between pharmacokinetics and nonpulmonary pharmacodynamic effects of theophylline

Concentration-effect relationships between oral theophylline and its nonpulmonary pharmacodynamic effects were examined in a double-blind, randomized, two-way crossover study in which 10 healthy subjects received a single dose of 500 mg ordinary-release theophylline or placebo. Mean plasma theophylline concentrations rose to 16.1 mg.L-1 at 1 hour and 16.8 mg.L-1 at 2 hours. Maximum decreases in plasma potassium (0.33 mmol.L-1) and magnesium (0.039 mmol.L-1) and increases in supine (11.1 mm Hg) and standing (8.0 mm Hg) diastolic blood pressure and plasma total cholesterol (0.59 mmol.L-1) occurred after the achievement of peak plasma theophylline concentrations (negative hysteresis). This delay is consistent with the intracellularly mediated effects of theophylline and with compartmental shifts of electrolytes. Discrepancies between the pharmacokinetic profile and pharmacodynamic effects should be borne in mind when assessing the duration of action of a drug.

Acute arsenic poisoning: absence of polyneuropathy after treatment with 2,3-dimercaptopropanesulphonate (DMPS)

Two men aged 19 and 21 years ingested 1 g and 4 g respectively from 3 kg of a white crystalline powder that they thought was a substance of abuse. It was later identified as almost pure arsenic trioxide. Both had nausea and vomiting and one developed acute renal failure. Each was treated with 2,3-dimercaptopropanesulphonate (DMPS), and made a full recovery with no evidence of prolonged renal or neurological impairment. The DMPS-arsenic complex is probably associated with lower penetration into the CNS and as a consequence treatment with DMPS may result in lower acute and chronic neurotoxicity than treatment with the currently standard recommended chelating agent dimercaprol (British Anti-Lewisite; BAL).

Pharmacotherapy of the depressed patient with cardiovascular and/or cerebrovascular illness

Cardiovascular and cerebrovascular disease are associated with a high incidence of depressive disorder. Despite this high level of co-morbidity, depressive disorders appear to go largely unrecognised and remain untreated. This may have serious consequences, as concomitant depression worsens the prognosis in patients with cardiovascular or cerebrovascular disease, increases medical costs, and delays return to work. Treatment with traditional tricyclic antidepressants is difficult in these patients because of the known cardiac effects. The favourable side-effect profiles of the 5-HT reuptake inhibitors suggest that they may offer therapeutic advantages, as they have little or no effect on cardiac conduction, do not cause orthostatic hypotension, and lack serious sequelae in overdose. The pharmacological profiles and the reduced potential of these newer antidepressant drugs to cause drug interaction show important differences that may be of clinical relevance in this patient population.

Intravenous pyridoxine in acute ethanol intoxication

Intravenous pyridoxine was evaluated as an agent for the reversal of ethanol-induced central nervous depression in a randomised double blind controlled study of 108 patients presenting with a clinical diagnosis of acute ethanol intoxication to two accident and emergency departments. Level of consciousness, measured by a modified Glasgow coma scale, showed no significant change after a single 1 g dose of intravenous pyridoxine when compared to controls given saline. The mean fall in blood alcohol concentration after one hour was 33 mg dl-1 (7.2 mmol l-1) in both groups suggesting that pyridoxine has no antidotal action and no short term effect on the rate of metabolism of ethanol.

Multiple-stimulus method for rapid collection of auditory brainstem responses using high-frequency (> or = 8 kHz) tone bursts

Auditory brainstem responses (ABR) to high-frequency (> or = 8 kHz) tone-burst stimuli have shown potential for objective early detection of ototoxicity. In the case of ill, unresponsive, or otherwise difficult-to-test individuals, the patient group for whom this test is targeted, a threshold-seeking process can be too lengthy. A new method is described for obtaining responses to several high-frequency tone bursts in the same amount of time as that used in obtaining a single responses. Using 10 normal-hearing subjects, four high-frequency tone-burst stimuli (14, 12, 10, and 8 kHz) were presented singly, then in a multiple-stimulus sequence with onsets separated by 10 msec. Wave V response latencies from the multiple-stimulus sequences are compared to those presented singly, with small but statistically significant longer latencies observed for all stimuli following the initial stimulus (14 kHz) in the multiple sequence. Test-retest reliability was comparable between multiple and single conditions. These findings support the development of this technique for clinical auditory monitoring.

Interaction between ethanol and opioids in a protozoan assay

Ethanol excess combined with opioids can be fatal due to their toxic interaction, yet the nature of the interaction is little documented. Since ethanol and some opioids have membrane stabilizing activity, the present study used a protozoan motility model to test the possibility that ethanol may interact with some opioids on this basis. The EC50 in motility reduction for ethanol, dextropropoxyphene, methadone and pethidine was 522.0 +/- 36.7 mM, 0.59 +/- 0.08 mM, 0.40 +/- 0.09 mM and 4.57 +/- 0.36 mM, respectively. When ethanol was combined with one of the three drugs in equitoxic doses at a ratio of 0.5:0.5, the predicted/observed EC50 values for ethanol-dextropropoxyphene, ethanol-methadone and ethanol-pethidine were 1.37, 1.11 and 1.00, each being close to unity, indicating an additive interaction. The interaction between ethanol and dextropropoxyphene was further explored at 0.25:0.75 and 0.75:0.25 equitoxic dose ratios, with the predicted/observed EC50 values of 0.98 and 0.97, also showing an additive interaction. This suggests that a non-specific interaction between ethanol and opioids may also take place in vivo, which could cause increased toxicity over and above the involvement of opioid receptors. Information from this study should aid understanding of the mechanism of interactions in human poisoning by agents with membrane stabilizing activity.

Folinic acid and enhanced renal elimination in formic acid intoxication

Ingestion of over 60 g of formic acid by an adult is potentially fatal. We report a case of a 36-year-old woman with a history of depression who ingested 110 g of formic acid. She survived a complicated intensive care hospitalization following usage of intravenous folinic acid, urinary alkalinization, intravenous furosemide and supportive care. We suggest a management protocol aimed at minimizing formate toxicity by enhancing hepatic formate degradation via the folinic acid 'one carbon pool' and by enhanced renal elimination of formate.

Subarachnoid haemorrhage associated with MDMA abuse

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Thromboxane A2 receptor antagonism and synthase inhibition in essential hypertension

Short-term effects of ridogrel, a combined thromboxane synthase inhibitor and receptor antagonist, were investigated in 16 patients with uncomplicated essential hypertension. After a 2-week placebo period without antihypertensive medication, patients were admitted to the hospital overnight on two occasions 3 weeks apart. On each occasion, they received two doses of either placebo or ridogrel (300 mg) 12 hours apart according to a double-blind crossover protocol. Renal and systemic thromboxane A2 and prostacyclin biosynthesis were investigated by measuring urinary excretion of thromboxane B2, 6-oxo-prostaglandin F1 alpha, and their respective 2,3-dinor metabolites using gas chromatography/mass spectrometry. Responses of platelets to a thromboxane A2 mimetic and to adenosine diphosphate were studied turbidometrically. Blood pressure was measured automatically at 20-minute intervals. Ridogrel reduced excretion of 2,3-dinor-thromboxane B2 and thromboxane B2 compared with placebo (21 +/- 6 versus 279 +/- 28 and 14 +/- 4 versus 39 +/- 9 ng/g creatinine, respectively; P < .0001 and P < .05). Excretion of 2,3-dinor-6-oxoprostaglandin F1 alpha and 6-oxoprostaglandin F1 alpha was increased by ridogrel compared with placebo (184 +/- 20 versus 146 +/- 11 and 86 +/- 9 versus 58 +/- 6 ng/g creatinine, respectively; P < .05). Ridogrel selectively antagonized platelet aggregation to the thromboxane mimetic (P < .0001). Blood pressure did not differ significantly between ridogrel and placebo treatment periods. Thus, in patients with essential hypertension, acute administration of ridogrel reduces renal and extrarenal thromboxane A2 biosynthesis, increases renal and extrarenal prostacyclin biosynthesis, inhibits thromboxane receptor-activated platelet aggregation, but has no effect on systemic arterial pressure.

Debits and credits in the management of depression

Concern over the cost of health care is playing an increasing role in Great Britain, but evaluation of benefit is generally inadequate. This is particularly true in the case of depression, for which the cost of drugs is 1.9% of the National Health Service pharmaceutical budget. Since differences in effectiveness between antidepressant drugs are difficult to demonstrate, quality-of-life studies may help to identify outcome differences. At present, the worst outcome of depressive illness--suicide--absolves carers from further costs. An assessment is needed which takes into account both the direct and indirect costs of depression; this should include the costs of investment into improving diagnosis. Even without financial analyses, it is clear that some cases of suicide can be prevented by prescribing less toxic drugs, but research is needed to investigate whether use of these drugs also reduces the costs of overdose.

High-frequency monitoring for early detection of cisplatin ototoxicity

Cisplatin can cause irreversible hearing loss initially detectable as impairment of high-frequency hearing with progression to lower frequencies. Many patients receiving cisplatin are too ill to tolerate lengthy audiometric testing. Therefore, a rapid and sensitive high-frequency monitoring strategy to detect cisplatin-induced ototoxicity is needed. Serial conventional (0.25 to 8 kHz) and high-frequency (> or = 8 kHz) threshold monitoring was performed in patients receiving cisplatin, resulting in 84% of ears showing hearing loss, of which 71% were detected first in frequencies of 8 kHz or greater. By analysis according to an individualized, specific high-frequency range, early identification of hearing loss occurred in 94% of ears showing change. This five-frequency procedure is a sensitive detector of ototoxicity and is proposed as an alternative monitoring protocol for patients receiving cisplatin who cannot tolerate extended testing.

Monoclonal plasmacytic ulcerative stomatitis. A plasma cell dyscrasia?

We report a case of extramedullary plasmacytoma that appeared in an uncharacteristic manner as an ulcerative stomatitis affecting particularly the tongue and buccal mucosa. The lesions were associated with a transient lichenoid skin rash. The literature is reviewed and comparisons made between this tumor and the related plasma cell dyscrasias of multiple myeloma and monoclonal gammopathy.