Germ cell neoplasms of head and neck soft tissues: a pathologic spectrum of teratomatous and endodermal sinus tumors

Germ-cell neoplasms, in particular teratomas with immature and mature somatic type tissues, are some of the most commonly found tumors in children. Approximately 5% of these neoplasms appear in one of several extracranial sites in the head and neck region. This study reports the clinical, pathologic and immunohistochemical findings in six germ-cell neoplasms occurring in the neck and facial areas. A mass was recognized at birth in five children, and the sixth patient was 2 1/2 years old at diagnosis. Four of the six neoplasms contained one or another element of endodermal sinus tumor; two of these had a mixed pattern of endodermal sinus tumor and teratoma. The other two cases were purely teratomas. The serum alpha-fetoprotein was known to be elevated in three children whose tumors had endodermal sinus elements; it returned to normal level in two of the children, but remained high in the one fatal case. Placental alkaline phosphatase and alpha-fetoprotein were demonstrated immunohistochemically in two of the three cases, with available tissue containing endodermal sinus tumor. Teratomatous metastases in ipsilateral cervical lymph nodes were found in one patient with a pure teratoma; that patient is disease-free one year after surgery. Only nine previous examples of endodermal sinus tumor have been reported in the head and neck region, exclusive of the central nervous system. There is one other case in the literature of a congenital cervicothyroidal teratoma with metastatic disease. These six neoplasms illustrate the clinical and pathologic spectrum in this nosologically homogeneous, but morphologically diverse, category of tumors.

The radiation dose to accompanying nurses, relatives and other patients in a nuclear medicine department waiting room

The radiation dose to accompanying nurses, relatives and other patients in a nuclear medicine department waiting room was assessed at 5 min intervals by observing the seating arrangement. The total radiation dose to each person was calculated, using fixed values of dose rate per 100 MBq activity for radionuclides, and applying the inverse square law. Radioactive decay and attenuation effects due to intervening persons were also taken into account. The median radiation doses to accompanying nurses, relatives and other patients were 2.3, 2.0 and 0.2 microSv with maximum values of 17, 33 and 5 microSv respectively. In all cases, the radiation dose received by patients was less than 0.2% of the radiation dose resulting from their own investigation. Also, the maximum radiation dose received by an accompanying nurse or friend was less than 1% of their appropriate annual dose limit. Similar values were obtained with calculations based on a 15 min time interval. The radiation doses received by those in a nuclear medicine department waiting room are small, and separate waiting room facilities for radioactive patients are unnecessary.

Iron deficiency in children

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Detection of feline calicivirus antigens in the joints of infected cats

Twelve specific pathogen free cats were used to investigate the role of calicivirus in causing lameness. These were divided into two groups each of six cats; one group of cats had previously been vaccinated, the other had not. Three cats in each group were given live vaccine virus (F9 related) by the subcutaneous route and two in each group were challenged intranasally with field virus (A4), either four or seven days before euthanasia. The other two cats were controls. Virus was isolated from the oropharynx of five cats and the conjunctiva of a single cat. Four of these cats had been given the field virus and two the vaccine strain; the latter two cats had been previously immunised and had high circulating neutralising antibodies to calicivirus. No virus was isolated from the joints of any cat but immunofluorescence examination revealed viral antigens within the synovial macrophages of 14 joints from five cats, three having been given the field virus and two the vaccine virus seven days before euthanasia. Immunofluorescence also demonstrated the presence of immunoglobulin and complement within synovial macrophages suggesting that the virus was in the form of an immune complex. No lameness was reported in any cat and the synovial histological changes were minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of changes in heart rate and aortic systolic pressure on left ventricular myocardial oxygen consumption in lambs

To determine whether changes in heart rate and aortic systolic pressure contribute equally to the determination of left ventricular myocardial oxygen consumption, we independently varied heart rate and pressure and compared the resultant oxygen consumption for similar rate-pressure products. In 6 young lambs which underwent atrioventricular node ablation, we varied heart rate by ventricular pacing at 250 beats/min, 300 beats/min, and 120 beats/min while aortic pressure remained stable and varied aortic systolic pressure by infusion of phenylephrine (to 132 +/- 15 mm Hg and 155 +/- 14 mm Hg) and by infusion of sodium nitroprusside (to 79 +/- 6 mm Hg) while heart rate was maintained stable at 200 beats/min. The 3 levels of change in aortic systolic pressure were chosen so that the ratepressure product during the pressure changes matched the rate-pressure product during the heart rate changes. We found that left ventricular myocardial oxygen consumption was the same at all 3 levels of the rate-pressure product whether heart rate was changed and pressure remained stable or pressure was changed and heart rate remained stable. Also, the correlation between oxygen consumption and the rate-pressure product was similar for both heart rate and pressure changes. During nitroprusside infusion at a fixed heart rate, oxygen extraction was significantly lower than during pacing at a heart rate of 120 beats/min when the rate-pressure product was comparable because of the direct vasodilatory effects of nitroprusside. We conclude that heart rate and aortic systolic pressure contribute equally to left ventricular myocardial oxygen consumption at the same rate-pressure product, even though there may be differences in myocardial blood flow and oxygen extraction.

Characterization of neurotensin binding sites in intact and solubilized bovine brain membranes

Analysis of the equilibrium binding of [3H]-neurotensin(1-13) at 25 degrees C to its receptor sites in bovine cortex membranes indicated a single population of sites with an apparent equilibrium dissociation constant (KD) of 3.3 nM and a density (Bmax) of 350 fmol/mg protein (Hill coefficient nH = 0.97). Kinetic dissociation studies revealed the presence of a second class of sites comprising less than 10% of the total. KD values of 0.3 and 2.0 nM were obtained for the higher and lower affinity classes of sites, respectively, from association-dissociation kinetic studies. The binding of [3H]neurotensin was decreased by cations (monovalent and divalent) and by a nonhydrolysable guanine nucleotide analogue. Competition studies gave a potency ranking of [Gln4]neurotensin greater than neurotensin(8-13) greater than neurotensin(1-13). Smaller neurotensin analogues and neurotensin-like peptides were unable to compete with [3H]neurotensin. Stable binding activity for [3H]neurotensin in detergent solution (Kd = 5.5 nM, Bmax = 250 fmol/mg protein, nH = 1.0) was obtained in 2% digitonin/1 mM Mg2+ extracts of membranes which had been preincubated (25 degrees C, 1 h) with 1 mM Mg2+ prior to solubilization. Association-dissociation kinetic studies then revealed the presence of two classes of sites (KD1 = 0.5 nM, KD2 = 3.6 nM) in a similar proportion to that found in the membranes. The solubilized [3H]-neurotensin activity retained its sensitivity to cations and guanine nucleotide.

Purification of the neurotensin receptor from bovine brain

The neurotensin receptor protein, solubilized with digitonin/asolectin from bovine cerebral cortex membranes, was purified to apparent homogeneity by affinity chromatography using immobilized neurotensin. The product exhibits saturable and specific binding of [3,11-tyrosyl-3,5-3H]neurotensin with an apparent affinity (Kd = 5.5 nM) comparable to that measured in intact membranes and crude soluble extracts. The affinity-purified material, after reduction with 100 mM dithiothreitol, in denaturing gel electrophoresis showed a single polypeptide of Mr 72,000. Under nonreducing conditions the apparent Mr, however, was 50,000, suggesting the presence of intramolecular disulfide bonds. The purified neurotensin receptor was judged to be homogeneous, in that (i) only a single polypeptide was detectable; and (ii) the overall purification was 30,000-50,000-fold, giving a specific neurotensin-binding activity close to the theoretical maximum.

Value for money in the health sector: the contribution of primary health care

Since the Alma-Ata Declaration in 1978, primary health care (PHC) has been seen in most countries as a vital part of any strategy to improve the health of the population. Economic evaluations of PHC delivery and PHC activities are therefore needed to assist in decision-making on resource use in the health sector. A report was prepared on such economic evaluations in the Commonwealth and this paper summarizes those findings which relate to developing Commonwealth countries. After a brief explanation of the main methods of economic evaluation, existing evaluations, classified according to the eight essential elements of PHC, are reviewed. The literature review throws up a number of methodological issues of which policy-makers need to be aware when interpreting evaluations. These are pointed out before moving on to a consideration of what lessons the literature may hold about the value and affordability of PHC and the most efficient ways of delivering PHC activities. The final section suggests that, although economic evaluation techniques have an important role to play in decision-making, they have not so far been used to best advantage. A number of ways in which health ministries could increase the usefulness of the evaluations they commission are considered.

Financial and economic aspects of environmental management for vector control

Short term economic benefits of resource development generally carry more weight in political decision-making than the adverse health effects such projects may have in the medium and long term. This problem is particularly acute in the case of water resource development projects which can often promote the prevalence and incidence of certain vector-borne diseases such as schistosomiasis and malaria. And while the agricultural sector is usually strengthened by production increase resulting from water resource development, the health sector may ultimately have to pick up the bill for disease control programmes which become necessary as a consequence. At its sixth meeting in Geneva, the WHO/FAO/UNEP Panel of Experts on Environmental Management for Vector Control (PEEM) discussed the financial and economic aspects of environmental management, and its cost effectiveness as a vector control measure. Their report is now available and in this article, Robert Bos and Anne Mills discuss some of the key findings.

Barrier contraception

Barrier contraception is a safe, effective, reversible form of contraception acceptable to many couples. The use of barrier contraception may protect against carcinoma of the cervix and sexually transmitted diseases. Distribution and education in the use of barrier contraception does not always require medical supervision. This must make it an attractive form of contraception for agencies supporting family planning programmes in developing countries. The only marketed recent advance in barrier contraception is the collatex sponge. Effectiveness rates range between 9 and 27 pregnancies per 100 woman-years. This is unlikely to make it the first choice of contraception for couples who would find an unintended pregnancy a severe problem, but the sponge will be acceptable to couples who are simply trying to delay a pregnancy. The new surge of interest in barrier contraception could lead to safer more effective forms of contraception being made available to women without medical supervision. This would have many advantages, but could also detract from the ability of family planning clinics to play an important role in preventative medicine for women.