Event recording in a clinical trial of a new medicine.

In a double-blind trial of the effect of zimelidine on weight and appetite 24 obese patients were allocated at random to receive either zimelidine or placebo for eight weeks followed by the alternative treatment for eight weeks. Possible adverse effects were elicited by asking patients at weekly intervals whether they had experienced any symptoms or ailments and recording all such "events" on a special form. A conventional checklist of symptoms was also used. Among 19 patients who completed the trial the two methods of recording yielded similar patterns of events. Of symptoms not on the checklist, insomnia was more common during treatment with zimelidine. Event recording was found to be a practicable and convenient method of detecting possible adverse effects.     

A model of T-cell unresponsiveness using the male-specific antigen, H-Y

Granuloma formation in schistosomiasis japonica differs in several respects from those observed in Schistosoma mansoni infections. We have utilized the lung granuloma model in mice sensitized with subcutaneous injection of Schistosoma japonicum eggs to study the kinetics and mechanisms of this response. Animals injected subcutaneously with a range of 50–50,000 S. japonicum eggs elicited a significant pulmonary granulomatous response around ova subsequently injected intravenously. The pulmonary granulomas were formed of macrophages, lymphocytes, and eosinophils. Both antithymocyte globulin and antieosinophil sera reduced significantly the size of the granulomas and depleted the corresponding cell. Nude athymic mice developed markedly reduced pulmonary granulomas as did mice treated with niridazole or hydrocortisone. Sensitization to the egg antigens was demonstrable as both immediate and arthus-type footpad responses. Our data show that cell-mediated pulmonary granulomas can form around S. japonicum eggs in animals previously sensitized by the subcutaneous route. This model may provide further insights into the pathogenesis of S. japonicum granuloma.     

Differential mitotic rates and patterns of growth in compartments in the Drosophila wing

In the wing disks of Drosophila slowly dividing cells of Minute mutations are progressively eliminated from Minute/Minute⁺ mosaic compartments by a process known as cell competition. From a study of two different Minutes we show here that the intensity of competition is greater in the more extreme Minute with the slowest rate of cell division. The way in which the more rapidly growing Minute⁺ clones grow and overcome the surrounding Minute cells is described and cell competition is shown to be a result of local interactions between slow- and faster-growing cells.     

Parameters of cell competition in the compartments of the wing disc of Drosophila.

When compartments in the wing disc of Drosophila are mosaic for two populations of cells, one of which is dividing more slowly, then the slower-growing population tends to be eliminated. The phenomenon leading to the disappearance of nonlethal, slowly dividing Minute cells was termed cell competition by Morata and Ripoll (1975) [Morata, G., and Ripoll, P. (1975). Develop. Biol.427, 211–221]. In this paper the different parameters of cell competition are explored. Starvation of the larvae rescued the Minute clones and permitted the following observations: The Minute clones grow to some extent before being out-competed. Prior to their disappearance, they become fragmented into small patches. Cell competition is greater in the centre of compartments than in the boundary regions. Possible causes of cell competition are discussed, as well as the hypothesis that the phenomenon may be related to the control of growth.     

Localization of the nucleolar organizer by computer-aided analysis of a variant no. 21 in a human isolate

Summary A variant chromosome no. 21 consisting of two stalks and two satellites in tandem was detected during a survey of a human isolate. The variant segregated in three generations of a large kindred. One male had the variant no. 21, a metacentric Y, and a 47, XXY complement; however, no other evidence of chromosomal nondisjunction was found. Computer-aided analysis of sequentially stained variant no. 21 chromosomes indicated that silver-stained material corresponded to the proximal stalk region (as defined defined by Giemsa). These data support the hypothesis that human nucleolar organizers are localized to the stalks of acrocentric chromosomes.     

Blood-pressure screening and supervision in general practice.

Since April 1975 all men aged 35-69 years registered with four general practices in west central Scotland have had their blood pressure checked whenever they visit the surgery. Although the practice locations range from rural to city centre and observers comprise receptionists, nurses, and doctors, a standard procedure has been adopted for the examination, recording, follow-up, and management of high blood pressure. The results confirm that raised blood pressure is common and often goes undetected. Even when hypertension is known, casual blood pressure readings often exceed accepted normal levels. The findings also show that a population may be routinely examined through normal contact with the family doctor, and that this can provide a convenient, acceptable, and effective means of detecting and reducing raised blood pressure.     

Effects of condensed phosphates on plant growth and phosphorus uptake

Summary Four condensed phosphates with large and small molecules, including ring and chain structures, were equivalent to orthophosphate in terms of phosphorus uptake and the dry matter yield of ryegrass grown in two soils in pots. This equivalence was maintained at each of 6 cuts during two seasons.Increasing N rate greatly increased uptake of applied phosphorus but there was no differential effect with different sources of phosphorus, nor was there any interaction between source and application rate.Phosphorus was not leached at any time, indicating that the phosphates were rapidly adsorbed by the soils.Fairly rapid hydrolysis of all the condensed phosphates occurred in a soil of neutral pH but a slower hydrolysis seemed to occur in an acid soil.There was a good correlation between the phosphorus uptake by ryegrass and the additional orthophosphate released by an acid hydrolysis of soil extracts.     

Unexplained hepatitis following halothane.

Full clinical and laboratory details of 203 patients with postoperative jaundice were submitted to a panel of hepatologists. All patients whose jaundice may have had an identifiable cause were excluded, which left 76 patients with unexplained hepatitis following halothane anaesthesia (UHFH). Hepatitis in 95% of these cases followed multiple exposure to halothane, with repeated exposure within four weeks in 55% of cases. Twenty-nine patients were obese, 52 were aged 41-70, and 53 were women. Thirteen patients died in acute hepatic failure. Rapid onset of jaundice after anaesthesia, male sex, and obesity in either sex were poor prognostic signs. Of the clinical stigmata of hypersensitivity, only eosinophilia was impressive. The UHFH group had a much greater incidence of liver kidney microsomal (LKM) and thyroid antibodies and autoimmune complement fixation than those patients whose jaundice related to identifiable factors. Thirteen of the 19 patients with LKM antibodies also had thyroid antibodies. In six patients retested two to three years later LKM antibodies had disappeared, although thyroid antibodies persisted. Rapidly repeated exposure to halothane may cause hepatitis, but such a complication is probably rare. Possibly obese women with a tendency to organ-specific autoimmunity may be more at risk. Nevertheless, the comparative risks of rapidly repeated halothane or non-halothane anaesthesia cannot be determined from the present data. If alternative satisfactory agents are available halothane should be avoided in patients with unexplained hepatitis after previous exposure, although in three to five patients with UHFH who were re-exposed to halothane jaundice did not recur.