Effects of storage on the methaemoglobin content of equine blood

Equine blood containing different levels of methaemoglobin was stored under varying conditions and the methaemoglobin content was monitored during the storage period. Only under aerobic storage at 4 degrees C did the methaemoglobin content of all samples appear to remain stable.

Recovery of anaerobic bacteria from small inocula: a model for blood culture studies

The recovery of anaerobic, facultative anaerobic, and aerobic pathogens from very small inocula was studied under conditions that could be related to routine blood culture procedures. Results with Brain Heart Infusion broth were unsatisfactory. Freshly prepared Brewer thioglycollate medium gave apparently good results, but there are disadvantages when this medium is used for blood culture. Results with Difco Thiol broth were disappointing. A modification of Robertson's cooked-meat broth supplemented with Brain Heart Infusion gave good recovery and sustained viability with a wide range of test organisms including exacting strains. The findings raise points of practical importance.

The Harlem regional stroke program: an overview

The Harlem regional stroke program has been a demonstration model designed to detect, treat, and follow up stroke and hypertension patients through collaboration with a municipal teaching hospital, community practitioners, local service organizations and a major medical school. Many aspects of the stroke program appear suitable for replication at the local or regional levels in varied settings. In particular, the program has demonstrated the need to link community outreach programs, stressing early detection and preventive-care education, with sustained treatment and follow-up programs. The stroke program has also suggested ways in which specialized programs can be incorporated into long-term comprehensive health planning and care facilities at local and regional levels.

Alpha1-fetorprotein concentrations in maternal serum during normal pregnancy

Measurement of amniotic fluid concentrations of alpha1-fetoprotein has been proposed as a potentially important screening test of fetal well-being. Because maternal serum is more easily obtainable, the present study was performed to determine if there is a definable normal pattern of maternal serum alpha1-fetoprotein levels during gestation. Sequential alpha1-fetoprotein determinations were performed throughout gestation on the serums of 151 women having apparently normal pregnancies. Before 13 weeks, all samples contained less than 20 nanograms of alpha1-fetoprotein per milliliter of serum, and in 12.5 per cent of normal pregnancies, alpha1-fetoprotein was still undetectable as late as 21 weeks of gestation. One normal term delivery followed a negative alpha1-fetoprotein determination at the 24th week of pregnancy. Beyond the 21st week of pregnancy, there was a wide range of normal absolute values noted between women at the same stage of pregnancy. Moreover, wide fluctuations in maternal serum concentrations of alpha1-fetoprotein were observed from point to point in specimens from individual women studied longitudinally throughout gestation. The distribution of alpha1-fetoprotein concentrations at each stage of pregnancy was skewed. We conclude that studies of maternal serum alpha1-fetoprotein concentrations are likely to be more meaningful from a diagnostic point of view prior to 21 weeks of gestation, when the range of circulating maternal alpha1-fetroportein values is relatively small. Undetectable maternal serum alpha1-fetoprotein as late as the 24th week of pregnancy is compatible witha viable conceptus. Because unexplained and marked elevations of maternal alpha1-fetoprotein may occur, particularly in the third trimester, it would appear inappropriate to base clinical decision on maternal serum alpha1-fetoprotein measurements alone, and such decisions certainly should not be taken after only single maternal serum alpha1-fetoprotein measurements. Finally, no correlation was found between maternal alpha1-fetoprotein concentrations near term and the birth weight of the infant.

Effects of intravenous histamine on pulmonary mechanics in nonasthmatic and asthmatic subjects

Histamine is thought to be one of the primary mediators of the airways response in allergic asthma. We have studied in detail in nonasthmatic and asthmatic volunteers the effects of its intravenous infusion on pulmonary mechanics. The doses used were similar in both groups and limited by vascular rather than pulmonary effects. Measurements were made of lung resistance, the subdivisions of lung volume, maximal flow, density dependence, lung elastic recoil and dynamic compliance. The only mean group changes were a decrease in dynamic compliance and increase in frequency dependence of compliance in the nonasthmatics. Although in nonasthmatic individuals, statistically significant changes occasionally occurred in some parameters, the response was variable on repeated studies and sufficiently small to be of questionable physiological significance. Some of the asthmatics developed larger changes, but these only occurred in those individuals whose preinfusion pulmonary function was abnormal. Our results suggest the possibility that altered prechallenge pulmonary function rather than an unusual sensitivity to histamine may determine the greater responses observed in asthmatics.

Tissue distribution of 3H-canrenoate potassium in rabbits

Plasma and various organ concentrations of canrenone, canrenoate, and total 3H-activity were measured following single doses of 20 mg of 3H-canrenoate/kg iv to rabbits. Organs studied included heart, lungs, brain, kidneys, liver, adrenal glands, and spleen. Canrenoate was shown to be in rapid equilibrium with canrenone. Both were eliminated from plasma and other tissues with a half-life of about 1 hr. Plasma concentrations of both drugs were equal as early as 10 min after intravenous drug administration. Canrenone was concentrated about 10-fold in organ tissues when compared to plasma, while no such preferential uptake was found with canrenoate. Total 3H-activity declined slowly in all tissues with a half-life of approximately 15 hr, indicating extensive metabolism and metabolite retention in the rabbit.

Effect of volume history on successive partial expiratory flow-volume maneuvers

In normal subjects, the second of two successive partial expiratory flow-volume (PEFV 2) curves often had higher isovolume maximal expiratory flow rates (Vmax) than the first (PEFV 1) (mean increase 30.2 +/- 13%). The higher Vmax on PEFV 2 was present only when there was a greater lung elastic recoil pressure (Pst(L)). In eight subjects the Pst(L) derived from sequential partial quasi-static pressure-volume curves, from interruption of the flow-volume maneuvers and at the start of the PEFV curves showed that isovolume upstream resistance increased although Vmax also increased after going to residual volume (RV). In four subjects the RV volume history did not change the pressure flow relationship across the upstream airways. If airways dimensions were the sole determinant of Vmax, then Vmax on PEFV 2 would be the same or smaller than on PEFV 1. That the opposite was observed in our study indicates that the increase in Pst(L), which results from parenchymal hysteresis, offsets any dimensional decrease in upstream airways due to airways hysteresis.

Tests of performance of anaerobic jars

This paper briefly reviews methods of assessing the in-use performance of anaerobic jars and outlines a simple system combining a rapid test of catalytic activity with a biological indicator that can detect defects in the jars after incubation.

Successful renal transplantation in Wegener's granulomatosis

Two patients with Wegener's granulomatosis, who were in complete remission secondary to cyclophosphamide therapy but who had end-stage renal failure, were treated with renal transplantation. Neither patient has clinical evidence of recurrent glomerulonephritis 10 and 28 months after receiving the renal transplants. Cytotoxic therapy has been proved to be highly effective in inducing and maintaining remission in patients with Wegener's granulomatosis; thus increasingly larger numbers of patients will be seen who, despite being maintained in complete remission, will have markedly impaired renal function due to previous acute damage. Renal transplantation can now be considered an acceptable alternative form of therapy in such patients.

Dynamic/static brain scintigraphy: an effective screening test for subdural hematoma

Dynamic perfusion scintigraphy of the brain was coupled with the delayed static scan in 5,853 studies as a screening test for neurological disease. Of approximately 1,000 patients referred for investigation for possible subdural hematoma (SDH), 23 proved to have SDH at surgery. Their scintigraphic abnormalities were analyzed and classified. When neither study indicates abnormality, angiography is not required, as SDH is unlikely. When the scintigraphic appearance is characteristic of SDH, angiography or surgical exploration is mandatory, since SDH is probably present. When the scintigraphic findings are consistent with but not typical of SDH, the study remains useful as a screening procedure, but the decision to proceed with angiography is based primarily on the neurological course.

Pneumatoceles as a complication of chemical pneumonia after hydrocarbon ingestion

Of 338 children with hydrocarbon ingestion, 134 (40 percent) had pneumonia. Pneumonia was most common after kerosene, furniture polish and lighter fluid ingestion. The pneumonia was most severe, however, with furniture polish. Pneumatoceles occurred in 14 children, most commonly with charcoal lighter fluid ingestion. Pneumatoceles generally appeared late, after the consolidation had cleared. Pneumatoceles were often large, septate and irregular, and sometimes contained fluid levels.

Double outlet right ventricle with l-malposition and uncommitted ventricular septal defect

A case is described which exhibited Double Outlet Right Ventricle (DORV) with l-malposition of the aorta in association with a ventricular septal defect of the noncommitted, atrioventricular canal variety. When the ventriculoarterial relationship of DORV is encountered, it is more usual to find the aorta to the right of the pulmonary artery. Review of the literature shows that examples of DORV and l-malposition have been described with subaortic, subpulmonary and doubly committed defects, but we are unaware of any previous example reported with a noncommitted defect. These findings indicate that DORV with l-malposition should be anticipated in association with the same accompanying defects as those described in DORV with d-malposition, and emphasize the necessity for adopting a segmental approach to nomenclature. They also have morphogenetic significance, suggesting that DORV with l-malposition is closely linked with the anomalies for anatomically corrected malposition and concordant (complete) l-transposition. The present case exhibited an electrocardiographic superior axis, which is probably related to the presence of the atrioventricular canal deformity. The coexistence of hypoplasia of the aortic isthmus is speculatively related to the presence of conal and valvar factors, which can be considered to have reduced aortic blood flow.

Cochlear damage resulting from kanamycin and furosemide

Permanent cochlear damage has been shown to occur in guinea pigs following the combined administration of kanamycin and furosemide. At the doses used, only a transient effect was measured with furosemide alone and no effect was detectable with kanamycin alone. This interaction results when a single subcutaneous dose of 400 mg/kg of kanamycin is followed in 2 hours by a single intravenous dose of furosemide. The dosage range for furosemide was 50 mg/kg for a just-detectable effect to 100 mg/kg for a very severe effect. Damage to the cochlea was ascertained by measures of the a.c. cochlear potential as well as surface preparation histology.

Studies on the synthesis and subcellular distribution of dopamine in the rat adrenal medulla

Rats received intravenous injections of 3H-tyrosine and were killed at various time intervals thereafter. 3H-dopamine (DA) in the adrenals reached a maximum within 1.5 min after the administration of 3h=tyrosine. From the 15th min it disappeared with an apparent half life of 90 min. 3H-Adrenaline (A) plus 3H-noradrenaline(NA) increased much more slowly and reached a plateau 120-240 min after the injection. The approximate synthesis rate of adrenal A plus NA, calculated from the specific activity curves, ranged from 0.3 to 2.2 nmoles/h per kg b.w. The highest value was noted the first few minutes, the lowest 1-2 hrs after the administration of 3H-tyrosine. In some experiments subcellular fractionation of the adrenals was performed. In untreated animals the amount of DA and A plus NA recovered from the supernatant fraction was about 10 and 8 per cent, respectively, of the total amount recovered from the supernatant and particulate fractions. In the adrenals of animals receiving 3H-tyrosine 3.75 or 60 min beforehand these figures were significantly elevated whereas the DA and A plus NA of the particulate fraction did not deviate significantly from control values. The specific activities of 3H-DA were the same in the supernatant and particulate fractions within 3.75 min after the injection of 3H-tyrosine.

A defined medium for the growth of Clostridium tetani and other anaerobes of clinical interest

The growth of six strains of Clostridium tetani was assessed in a chemically supplemented commercially available defined medium. All strains grew reliably even after 12 serial passages, and two strains produced demonstrable toxic activity after passage. Consistent growth of the test strains could also be obtained on a solid version of this medium ("CA109-S" medium), and the strains could be serially passaged on this medium. Preliminary evidence is presented that the medium supports the surface growth of some other test anaerobes. Such a defined solid medium might prove of value in further studies on the surface growth of C. tetani and of other anaerobes of clinical interest.

Persistent transitional circulation

Six infants presented within 24 hours of birth with cyanosis. The clinical findings, combined with catheter studies in 4 cases, led to the conclusion that there was a persistent fetal direction of ductus arteriosus flow with pulmonary hypertension, i.e. a `persistent transitional circulation'. The occurrence was 1/1454 live births, and it is thus an important condition to recognize and differentiate from cyanotic congenital heart disease. 4 of the children went through the transition to a normal infant circulation with medical treatment alone, one died before this occurred, and one recovered after an exchange transfusion. The cause of the persistent transitional circulation is not clear, but it is probably the end result of several different pathological processes.

The recovery of anaerobic bacteria from swabs

When a standard sample of simulated exudate containing known numbers of anaerobic bacteria was taken up on a swab and plated on solid medium, the number of colonies subsequently cultured represented a very small proportion of the original sample. Evidence is produced that the apparent loss is not primarily attributable to inactivation on the swab but rather to retention of organisms on the swab. This was demonstrable with Clostridium welchii and with Bacteroides species that have hitherto been regarded as relatively oxygen-sensitive.When stock strains of Bacteroides species were held for some hours on swabs, some progressive loss of viability was demonstrable. A measure of protection was afforded when these organisms were held aerobically on blood agar medium, but a very exacting anaerobe and some wild strains of faecal anaerobes showed gradual inactivation under these conditions.These findings may have important implications in relation to currently employed bacteriological sampling procedures with swabs in clinical practice.