Hippocampal function in schizophrenia and bipolar disorder.

BACKGROUND: The hippocampus plays a central role in memory formation. There is considerable evidence of abnormalities in hippocampal structure and function in schizophrenia, which may differentiate it from bipolar disorder. However, no previous studies have compared hippocampal activation in schizophrenia and bipolar disorder directly. METHOD: Fifteen patients with schizophrenia, 14 patients with bipolar disorder and 14 healthy comparison subjects took part in the study. Subjects performed a face-name pair memory task during functional magnetic resonance imaging (fMRI). Differences in blood oxygen level-dependent (BOLD) activity were determined during encoding and retrieval of the face-name pairs. RESULTS: The patient groups showed significant differences in hippocampal and prefrontal cortex (PFC) activation during face-name pair learning. During encoding, patients with schizophrenia showed decreased anterior hippocampal activation relative to subjects with bipolar disorder, whereas patients with bipolar disorder showed decreased dorsal PFC activation relative to patients with schizophrenia. During retrieval, patients with schizophrenia showed greater activation of the dorsal PFC than patients with bipolar disorder. Patients with schizophrenia also differed from healthy control subjects in the activation of several brain regions, showing impaired superior temporal cortex activation during encoding and greater dorsal PFC activation during retrieval. These effects were evident despite matched task performance. CONCLUSIONS: Patients with schizophrenia showed deficits in hippocampal activation during a memory task relative to patients with bipolar disorder. The disorders were further distinguished by differences in PFC activation. The results demonstrate that these disorders can distinguished at a group level using non-invasive neuroimaging.

The effect of carbidopa and indomethacin on the renal response to gamma-L-glutamyl-L-dopa in normal man.

1. The renal response to gamma-L-glutamyl-L-dopa (gludopa, 25 micrograms kg-1 min-1) was investigated in seven normal male volunteers. The effects of oral carbidopa (100 mg) and indomethacin (100 mg) on the response to gludopa were studied in the same group. 2. Gludopa at this dose level produced a 900-fold increase in urine dopamine excretion and caused a natriuresis and suppression of plasma renin activity with only minor effects on pulse rate and blood pressure. 3. Carbidopa inhibited the increase in dopamine excretion by 97% and abolished the renal actions of gludopa. 4. The increase in urine dopamine produced by gludopa was not altered by indomethacin and the urine sodium output was similar to that caused by gludopa alone. 5. Gludopa is an effective renal dopamine prodrug whose activity can be blocked by the dopa decarboxylase inhibitor carbidopa. The results with indomethacin suggest that dopamine and the prostaglandins form separate natriuretic systems in the kidney.

Lack of effect of gliclazide on early diabetic nephropathy and retinopathy: a two-year controlled study.

This study has attempted to document a specific haemovascular action of gliclazide on the reversal of early diabetic microangiopathy. A prospective double-blind controlled study was performed over 2 years, comparing gliclazide versus placebo in insulin-treated and gliclazide versus glibenclamide in non-insulin-treated diabetic subjects, after a 1-year run-in period. Glycaemic control was not significantly different in gliclazide- and non-gliclazide-treated subjects before or after the commencement of active therapy. Following treatment with gliclazide in 17/32 insulin-treated and 8/17 non-insulin-treated subjects with Albustix-negative proteinuria, there was no difference in retinopathy score, total proteinuria or the renal clearance of creatinine, albumin, transferrin and immunoglobulin G. In the insulin-treated group, progression of retinopathy was observed in approximately one-third of subjects, but no parameter of proteinuria progressed over 2 years. Thus, this study did not detect a reversal of the parameters measured and does not support an action of gliclazide on diabetic microangiopathy, independent of its hypoglycaemic action.

High flow oxygen therapy for pneumatosis coli.

Symptomatic and radiological resolution of pneumatosis coli was achieved by intermittent high flow oxygen therapy in five patients. In each case the extent of the disease was defined by colonoscopy and contrast radiography before treatment. Despite the confirmation of pneumocyst resolution, recurrence of colonic gas cysts was noted in two patients at six months and one year after treatment. Bacteriological studies indicated that resolution of the disease, induced by oxygen therapy, was not associated with eradication of anerobic bacteria from stool and colonic mucosa. The clinical features and response to treatment of this group of patients are discussed, with particular reference to previously reported methods of oxygen administration.

Antimicrobial proteins in sterilised human milk.

Human milk contains factors such as IgA and lactoferrin that increase the newborn infant's resistance to infection. Preterm infants are fed pooled milk, which is normally sterilised by heating. After standard heat sterilisation IgA and lactoferrin were undetectable in milk samples. Pasteurisation also sterilised milk samples even after heavy artificial contamination and did not damage the proteins. Gamma-irradiation sterilised equally effectively but caused some denaturation of IgA and lactoferrin. Since most of the milk samples were sterile or had only light contamination with skin bacteria, there seems to be no need for routine sterilisation. If sterilisation is necessary, the method used should be chosen to minimise damage to milk proteins.

Appearance of specific colostrum antibodies after clinical infection with Salmonella typhimurium.

Colostrum and serum antibodies to Salmonella typhimurium have been found in three patients after clinical gastrointestinal infection during pregnancy. High levels of colostrum IgA agglutinins were directed specifically against both the flagellar and somatic antigens of the infective organism. The levels of colostrum agglutinating activity exceeded those found in the patients sera, while control colostrum gave negative results.