Mutations in the gene encoding B1 subunit of H+-ATPase cause renal tubular acidosis with sensorineural deafness.

H+-ATPases are ubiquitous in nature; V-ATPases pump protons against an electrochemical gradient, whereas F-ATPases reverse the process, synthesizing ATP. We demonstrate here that mutations in ATP6B1, encoding the B-subunit of the apical proton pump mediating distal nephron acid secretion, cause distal renal tubular acidosis, a condition characterized by impaired renal acid secretion resulting in metabolic acidosis. Patients with ATP6B1 mutations also have sensorineural hearing loss; consistent with this finding, we demonstrate expression of ATP6B1 in cochlea and endolymphatic sac. Our data, together with the known requirement for active proton secretion to maintain proper endolymph pH, implicate ATP6B1 in endolymph pH homeostasis and in normal auditory function. ATP6B1 is the first member of the H+-ATPase gene family in which mutations are shown to cause human disease.

Lipids and lipoprotein fractions after cyclopenthiazide and oxprenolol: a double-blind crossover study.

A double-blind crossover study was carried out to investigate the effects of cyclopenthiazide and oxprenolol on blood lipids in 20 previously untreated patients with mild to moderate hypertension. After a 4-week placebo period, patients received at random either 8-weeks' treatment with the two drugs followed by 8 weeks on cyclopenthiazide alone, or the reversed sequence. Daily doses were 160 mg slow-release oxprenolol and/or 0.25 mg cyclopenthiazide during the first 4 weeks of each treatment period, after which the dosage was doubled. Data from 13 patients who completed the trial showed no significant changes in the blood levels of triglycerides, total cholesterol or LDL and HDL cholesterol fractions. These findings are discussed in relation to published studies on the effects of other beta-blockers on blood lipids.

Hypertension following renal trauma.

Renovascular hypertension is an unusual complication of renal trauma, occurring in approximately 5% of cases. It occurs predominantly in young males following road traffic accidents (RTA) or blunt abdominal trauma. The interval between injury and development of hypertension varies from two days to 14 years but presentation may be acute with hypertensive encephalopathy. Hypertension developing within a few months of injury may be treated conservatively. Conservative treatment more than one year after injury is associated with an increased risk of persistent hypertension. All cases of renal trauma should be followed with regular blood pressure (BP) recording for at least the first year after injury.

Primary malignant retroperitoneal germ cell tumour presenting with accelerated hypertension.

A 42 year old man presented with accelerated hypertension and an abdominal mass that proved to be a primary malignant retroperitoneal germ cell tumour involving renal vessels. The hypertension resolved with chemotherapy. To our knowledge this is the first case of a primary malignant retroperitoneal germ cell tumour to present with accelerated hypertension.

Optic neuritis and myelopathy in systemic lupus erythematosus.

The optic neuritis of systemic lupus erythematosus (S.L.E.) more frequently results in the persistence of a central scotoma or complete blindness after a single attack than demyelinating optic neuritis, although the initial clinical presentations may be identical. A significant number of patients, however, recover normal vision. Optic neuritis may be the presenting symptom of S.L.E. and as myelopathy may also occur in the course of the disease, confusion with multiple sclerosis may result, especially if there are no arthritic, cutaneous nor visceral manifestations. We report a case of lupus optic neuritis associated with anticardiolipin antibodies and a circulating lupus anticoagulant and suggest these may be a marker for vasculitic optic neuritis and play a role in its aetiology.

Nutritional osteomalacia presenting with plantar fasciitis.

We report five patients with nutritional osteomalacia who presented with the symptoms and signs of plantar fasciitis. All the patients were Asian vegetarian women. All improved with treatment of the osteomalacia, albeit slowly in two cases.

Erosive rheumatoid arthritis co-existing with systemic lupus erythematosus. A report of a case, also showing atlanto-axial subluxation.

A 28-year old female is described with a 12-year history of seropositive, erosive rheumatoid arthritis. Subsequently, she developed systemic lupus erythematosus diagnosed both serologically and on renal biopsy. As has previously been emphasised, these two diseases occur rarely in the same patient. HLA typing revealed the patient was HLA - B8 positive and that she had inherited this genetic marker from her mother who is Irish, rather than from her West Indian father. The patient has developed marked atlanto-axial subluxation, a feature not noted in six patients previously described as having both diseases.