Effects of OKY-046 and nifedipine in cyclosporine-induced renal dysfunction in rats

Cyclosporine (CsA) (37.4 mumol/kg per day for 7 days) treated female Wistar rats exhibited significantly decreased creatinine clearance (Ccr) and body weight loss (BWL), but had neither proteinuria (PU) nor alteration in their urine volume (V). Light microscopic (LM) sections of rat kidneys showed that all kidneys were affected by lesions, mainly diffuse vacuolization. These changes were associated with decreased urinary excretion ratios of 6-ketoprostaglandin F1 alpha to thromboxane B2 (6kPGF1 alpha/TXB2) and prostaglandin E2 to TXB2 (PGE2/TXB2). When OKY-046, a TXA2-synthetase inhibitor or nifedipine (NFD), a calcium channel blocker and an antagonist of endotheline (ET), were administered in addition to CsA, they restored Ccr and increased urine V but they did not prevent BWL. LM sections showed that only 5 or 7 out of 9 kidneys of animals were affected, respectively. These changes were associated with prevention of the diminished ratios of urinary PGE2/TXB2 and 6kPGF1 alpha/TXB2 mainly in the OKY-046 treated animals. In conclusion, our results suggest that inhibitors of TXA2 or antagonists and/or inhibitors of endothelin play a protective role in the development of the dysfunction induced by CsA. However, the protection observed using OKY-046 and NFD did not reach that obtained by evening primrose oil (EPO) or Ketanserine (KTS), substances which prevented the fall of Ccr and BWL. Furthermore, with these protective agents only 5 out of 9 kidneys were affected and the lesions were of minor importance.

'Too tired to go to the support group': a health needs assessment of myalgic encephalomyelitis

BACKGROUND

Myalgic encephalomyelitis (ME) is a mysterious and controversial condition. Debate has centred upon its causation, and the purchasing question-which services to commission for people with ME-has not been addressed.

METHODS

A health needs assessment was made of people with ME in Wakefield, based upon published (including grey) literature, and local informants.

RESULTS

Previous studies have mostly reflected institutional outbreaks; local needs will reflect community, sporadic cases but there is little information about these. The very wide estimates of prevalence (between zero and 57000 for a district the size of Wakefield) indicate a fundamental problem over the validity of the concept of ME. Four sets of health needs emerged from the literature and from local informants: a medical diagnosis, rest, specific treatments and social care. All four are highly debatable.

CONCLUSION

There are no proven services or interventions which the health authority should purchase for people with ME. Purchasing, being a blunt tool for service change, is unlikely to improve health care given the disagreements over the condition.

Effectiveness of natural oils as sources of gamma-linolenic acid to correct peripheral nerve conduction velocity abnormalities in diabetic rats: modulation by thromboxane A2 inhibition

Reduced nerve conduction velocity (NCV) in experimental diabetes can be prevented by evening primrose oil (EP), which is rich in gamma-linolenic acid (GLA). This study examined the efficacy of natural GLA sources, blackcurrant (BC), borage (BO) and fungal (FU) oils, compared with EP, in correcting motor and sensory NCV deficits in streptozotocin-diabetic rats, and any potential contribution of thromboxane (TX) A2 synthesis using the TX antagonist, ZD1542, alone and jointly with GLA-rich oils. Sciatic motor NCV, 20% reduced by 8 weeks of diabetes, was partially (16%) corrected by 2 weeks ZD1542 treatment. 1% BC, BO, FU and EP dietary supplementation caused 11%, 32%, 41% and 53% NCV ameliorations, respectively. A 2% EP diet, more closely matching the GLA intake from the other oils, caused 67% correction. Joint oil/ZD1542 treatment produced further motor NCV improvements for BC and, particularly, BO. A 13% sensory saphenous NCV deficit in diabetic rats was ameliorated by 31%, 24%, 49%, 81%, 70% and 94% for ZD1542, BC, BO, FU, EP and 2% EP, respectively. Joint ZD1542-oil treatment further improved NCV, particularly for BO. Therefore, efficacy against experimental diabetic neuropathy is not predictable from the GLA content of natural oils, EP consistently outperforming BC, BO and FU. Increased TXA2 with diabetes made a minor contribution to NCV deficits, but blockade improved the response to BO.

Essential fatty acid supplementation in chronic hepatitis B

BACKGROUND

Dietary supplementation with essential fatty acids and polyunsaturated lecithin may improve biochemical and histological parameters in liver disease.

METHODS

Ten patients with serological and histological evidence of chronic hepatitis B received capsules of the polyunsaturated fatty acid-rich evening primrose oil in a dose of 4 g daily for 12 months, while a matched group received liquid paraffin capsules as a placebo.

RESULTS

Compared to the placebo group, the patients receiving evening primrose oil showed no improvement in either biochemical or histological indices of liver damage, or in the rate of loss of circulating e antigen.

CONCLUSIONS

Dietary, supplementation with this dose of essential fatty acids is unlikely to be of benefit in chronic hepatitis B.

Essential fatty acid deficiency in erythrocyte membranes from chronic schizophrenic patients, and the clinical effects of dietary supplementation

There is now convincing evidence that membrane phospholipid metabolism is abnormal in schizophrenic patients. Our own studies, consistent with those of other research groups, have shown marked depletion of essential fatty acids, particularly arachidonic acid and docosahexanoic acid, in red blood cell membranes from schizophrenic patients relative to healthy control subjects. We also present preliminary evidence that similar abnormalities are present in first degree relatives of schizophrenic patients. Furthermore, it appears that changes in diet, which modify membrane levels of fatty acids, can have significant effects upon symptoms of schizophrenia and tardive dyskinesia (TD). Thus, we have found that schizophrenic patients who eat more (n-3) fatty acids in their normal diet have less severe symptoms. In a pilot study of (n-3) fatty acid supplementation we observed significant improvement in both schizophrenic symptoms and tardive dyskinesia over a 6 week period.

Membrane fatty acids, niacin flushing and clinical parameters

Clinical definitions of schizophrenia are unreliable and difficult to use. The niacin flush test, which involves prostaglandin-induced vasodilatation, offers a method of exploring essential fatty acid metabolism in schizophrenic patients and may serve to define a subgroup of patients. In a multicentre study of schizophrenic patients with negative symptoms, we have examined the clinical accompaniments of the niacin response. Patients failing to flush with niacin showed significantly reduced levels of arachidonic and docosahexaenoic acids. Conversion from non-flushing to flushing during the 6 month supplementation period was predicted by an increase in arachidonic acid levels in red blood cell membranes irrespective of nature of supplementation. In this study, patients were selected for their negative symptoms and, therefore, it was not surprising that further measures of negative or positive symptoms did not predict flushing. However, an increased score for affective symptoms was significantly associated with a positive flush response. The stability of the niacin test needs to be examined in relation to the periodicity of symptoms in schizophrenia and manic depressive illness. New information on the anandamide system suggests that it may be associated with periodic phenomena and should be investigated in relation to the niacin test.

Successful treatment of a patient with octreotide-resistant necrolytic migratory erythema

We report a patient with the glucagonoma syndrome and octreotide-resistant necrolytic migratory erythema (NME). The NME responded on two occasions to an intravenous infusion of essential fatty acids (EFA) and amino acids (AA). A deficit of serum EFA prior to treatment was corrected following the infusion, whilst plasma AA were low before and after treatment. These findings indicate that NME, in the glucagonoma syndrome, may respond to correction of the EFA deficit, and that NME may be a disease of EFA deficiency.

Is evening primrose oil of value in the treatment of premenstrual syndrome?

A systematic literature search of clinical trials of evening primrose oil (EPO) for the treatment of the premenstrual syndrome (PMS) was carried out with a view to performing a meta-analysis. Only seven placebo-controlled trials were found but only in five trials was randomization clearly indicated. Inconsistent scoring and response criteria made statistical pooling and hence a rigorous meta-analysis inappropriate. The two most well-controlled studies failed to show any beneficial effects for EPO, although because the trials were relatively small modest effects cannot be excluded. Nonetheless, on current evidence EPO is of little value in the management of premenstrual syndrome.

Evening primrose oil (Epogam) in the treatment of chronic hand dermatitis: disappointing therapeutic results

BACKGROUND

Hand dermatitis is a common therapeutic challenge with limited and unsatisfactory therapy modules. A possible beneficial role of oral evening primrose oil needs to be investigated.

OBJECTIVE

Pharmacological doses of gamma-linolenic acid (GLA) could improve the water permeability barrier of the epidermis in chronic hand dermatitis. Clinical improvement, changes in the lipogram and epidermal lipid composition could define functional improvement of the skin. Electron-microscopic evaluation of the epidermal lipid bilayer could underline the efficacy of essential fatty acids in chronic hand dermatitis.

METHODS

Thirty-nine patients with chronic (> 1 year), stable hand dermatitis entered a 24-week double-blind placebo-controlled trial. Patch test with the European standard of allergens, haematogram and serum IgE values were determined before commencement of the study. Active therapy (600 mg/day of GLA) was administered to half the patient group. Medication was given for 16 weeks and observations continued for another 8 weeks. Patients were assessed clinically, using a visual analogue scale at 4-week intervals. Plasma and red blood cell lipograms, as well as skin biopsies, were taken before therapy, after the 16-week supplementation period and at week 24. Tissue was used for histological evaluation, electron-microscopic assessment and epidermal lipid analysis.

RESULTS

Improvement in clinical parameters was present in the Epogam and placebo groups, but no statistical difference could be confirmed between the groups. Haematogram, blood and epidermal biochemistry were normal at baseline. No change in the lipid composition of plasma red cells or epidermis could be detected during the trail. Ultrastructurally skin specimens showed no change during the study period.

CONCLUSION

The study indicates that the therapeutic value of orally administered GLA for chronic hand dermatitis is not superior to that of placebo.

Additive benefits of EFAs in dogs with atopic dermatitis after partial response to antihistamine therapy

It has been reported that 20 to 70 per cent of atopic cases in the dog can be controlled with antihistamines, though the effective antihistamine cannot be predetermined. Combination therapy with essential fatty acids (EFAs) and antihistamines has been shown to be useful in dogs. All of the work published to date has been performed in open studies, without the use of placebo, and in dogs where the aim has been to control pruritus as a symptom rather than that caused specifically by atopy. The aim of this study was to assess the combined effects of four antihistamines; hydroxyzine, chlorpheniramine, cyproheptadine and clemastine; with both an EFA supplement and a placebo of olive oil, in 25 dogs to control pruritus in clinically proven cses of atopy.

[Pharmacotherapeutic use of antipruritic drugs in skin diseases]

Pruritus is a predominant and serious phenomenon of various skin diseases. As mediators of pruritus, histamine, serotonin (hydroxytryptamine), eicosanoids, neuropeptides, cytokines and proteases are known. The symptomatic treatment of pruritus is variable. Glucocorticoids are well known antipruritic drugs. H1-antihistaminics are used frequently. But the efficacy of these drugs is questionable in dogs. Additionally, mast cell stabilisators, unsaturated fatty acids (i. e. primrose oil, fish oil) and other antipruritic agents (local anesthetics) are used.

Adjuvant therapy with essential fatty acids (EFAs) for primary liver tumors: some hypotheses

Hepatocarcinoma is responsible for approximately 1 million deaths annually. It is usually discovered at an advanced stage and, if inoperable, has a poor prognosis. New therapies combining chemotherapy, hyperthermia, radiotherapy and immunomodulators have been recently attempted with various levels of success. Once the tumor is detected at an early stage, some possibilities of cure seem to emerge either by intratumoral percutaneous injection (PEI) of alcohol or by chemoembolization and interstitial hyperthermia. When the tumor volume is more than 5 cm, these therapies are less successful and radiotherapy can be used. All the techniques described have some limits; PEI, for instance, does not achieve a complete eradication of lesions > 3 cm and a non-homogenous alcohol distribution within the tumor leads to areas of necrosis. Radiotherapy, even if effective, is limited by dose-related radiation hepatitis. Another important limiting factor is the incomplete response to therapy and tumor recurrence. Essential fatty acids, especially gamma linolenic acid (GLA) and eicosapentaenoic acid (EPA) are discussed here for their ability to control primary tumor proliferation and increase response to chemotherapy, radiotherapy and hyperthermic treatment, thanks to their effects on cellular membranes (increased lipoperoxidation and modification of tumor stroma).

Effects of anti-oxidant treatment on sciatic nerve dysfunction in streptozotocin-diabetic rats; comparison with essential fatty acids

In Study 1, the effects of treatment of streptozotocin-diabetic rats with the antioxidants, probucol or vitamin E were compared. Untreated diabetic rats showed a reduction of 45% (p < 0.01) in nerve laser Doppler flux, which was used as an index of nerve blood flow. In diabetic rats treated with either probucol or vitamin E nerve Doppler flux was reduced by only 13 or 16%, respectively (p < 0.01 for either compared to untreated diabetic rats). A second study examined the effects of treatment with evening primrose oil either alone or in combination with probucol. Reduced nerve Doppler flux was reproduced in untreated diabetic rats (47%; p < 0.01). In parallel diabetic groups, nerve Doppler flux was reduced by only 14% with evening primrose oil alone and by 8% with evening primrose oil plus probucol (both p < 0.01 vs untreated diabetic rats). Both treatments were also associated with marked attenuation of motor and sensory nerve conduction velocity deficits. Measurements on plasma from rats showed normalisation of triglyceride levels by probucol treatment without an effect on those of cholesterol in Study 1. In Study 2, the converse was true for evening primrose oil treatment, whilst the combined treatment lowered both plasma triglycerides and cholesterol. This work indicates similar effects of antioxidants and evening primrose oil against reduced nerve Doppler flux and conduction velocity in diabetic rats, with dissimilar actions on plasma triglycerides and cholesterol.

Effects of evening primrose oil treatment on sciatic nerve blood flow and endoneurial oxygen tension in streptozotocin-diabetic rats

Evening primrose oil (EPO) is rich in the omega-6 essential fatty acid component, gamma-linolenic acid. The aim of the investigation was to determine whether EPO treatment prevented a reduction in sciatic nerve perfusion and oxygenation in streptozotocin-diabetic rats. Rats were treated from diabetes induction with 10 g EPO kg-1 day-1. Sciatic blood flow was measured by microelectrode polarography and hydrogen clearance. Diabetes caused 47.7% +/- 3.4% (P < 0.001) and 58.8% +/- 4.8% (P < 0.001) reduction in the nutritive (capillary) and the non-nutritive (large vessel) components of endoneurial blood flow, respectively, which were prevented by EPO. Treatment had no significant effect on nutritive flow in non-diabetic rats; however, the rate of non-nutritive flow increased by 97.7% +/- 38.9% (P < 0.01). Sciatic endoneurial oxygen tension was measured by microelectrode polarography. Diabetes resulted in a 44.7% +/- 3.4% reduction in mean oxygen tension (P < 0.001), which was largely (82.3% +/- 10.2%) prevented by EPO treatment (P < 0.001). Thus, EPO prevents impairment of blood flow and endoneurial oxygenation in experimental diabetes. It is likely that this neurovascular action accounts for the beneficial effects of treatment on nerve function in diabetic rats and patients.

Effect of essential fatty acids on circulating T cell subsets in patients with colorectal cancer

The effect of essential fatty acids (EFA), given orally as dietary supplements, on the responsiveness in vitro of peripheral blood lymphocytes (PBL), to the mitogen concanavalin A have been studied in 10 patients with localized and 14 patients with advanced colorectal cancer. The degree of lymphocyte activation was assessed by measuring the amount of tritiated [3H]thymidine incorporated into newly synthesised lymphocyte DNA. The results were expressed as stimulation indices. T cell responses to concanavalin A stimulation showed a significant reduction of stimulation indices following EFA supplementation, in both the localized (P = 0.026) and advanced (P = 0.016) tumour groups, when compared with pretreatment activity in vitro. Mixing experiments, using EFA-supplemented and non-EFA-supplemented lymphocytes with concanavalin A, suggest no enhancement of T suppressor cell activity. Cell surface marker analysis (fluorescence-activated cell sorting for CD phenotyping) revealed a reduction of absolute numbers of CD4+ and CD8+ lymphocytes following EFA supplementation. The stimulation indices returned to pre-supplementation values 3 months following cessation of EFA intake. There was no significant change of these indices in the control (no EFA supplementation) advanced tumour group tested. This study suggests that EFA supplementation in patients with colorectal cancer selectively reduces circulating PBL, and T cell subset (including suppressor cells) numbers and/or activity. Such effects may have an important outcome in patients with malignant disease.

Essential fatty acids and malignant disease

EFAs have shown promising anti-tumour effects in cell culture studies and in animal models. However, it is also clear that in man EFAs can have marked immunomodulatory effects, in particular, inhibiting certain aspects of host anti-tumour defence mechanisms (natural cytotoxicity and cytokine production). Further careful studies are required to evaluate more precisely the role of EFAs in the treatment of malignant disease in man.