Small Progressive Increase Research Articles

Aortic dimensions in a large Australian adult cohort. New normal range?

Abstract Background There is little published data worldwide about the normal range of aortic dimensions in adults. Guidelines for dilated aortic dimensions and recommendations for surgery are based on small population cohorts and absolute values. Adjustment for BSA and height are becoming more accepted, however the normal range of aortic dimensions for a large population has not been previously published. We present the distribution of aortic dimensions in a large Australian population, with indexation for BSA and height as well as centiles of age. Methods All patients >18 years of age attending for routine echocardiography at our institution from 2007-2022 were included in the database. Measurements of aortic root, sinotubular junction and ascending aorta using ASE criteria were collated. Dimensions were adjusted for BSA and height. Data was analysed for centiles of weight and height and across decades of age. Results A total of 117,912 patients were included in the analysis, aged 62.8+17.6 years (range 18-107), 59% male, 83.7+21.1 kgs (range 32-337) and 169.8+10.3 cm (range 107-218). The aortic root and ascending aortic dimensions are presented in absolute values (average + SD), and height adjusted (cm/m) and BSA adjusted (cm/m2) values. Data was expressed per centile of height, age and weight. There was a progressive increase in aortic dimensions as expected for increasing height, however a robust relationship was identified when dimensions were indexed according to height at all centiles regardless of age and body weight. In contrast, when adjusted for BSA, the aortic dimensions were progressively and predictably under-reported in patients over 80kg for assessment for normal vs dilated. When analysed for centiles of age, there was a small progressive increase in dimensions observed with increasing age. The indexation for height was independently robust across patients of all centiles of height. Conclusion Aortic dimensions are consistently 2.0+0.5 cm/m when adjusted for patient height across all body weight and age centiles. Adjustment for BSA in patients over 80kg tends to under-represent aortic dimensions when assessing for dilatation. Dimensions tend to increase gently with increasing age. We propose a new nomogram for normal aortic dimensions in adults.

The effects of haloalkene cysteine conjugates on cytosolic free calcium levels in LLC-PK 1 cells—studies utilising digital imaging fluorescence microscopy

The aim of this study was to examine the effect of haloalkene S-cysteine conjugates on cytosolic free Ca 2+ levels in renal epithelial cells using digital imaging fluorescence microscopy (DIFM). S-(1,2,3,4,4-pentachloro-1,3,-butadienyl)- l-cysteine (PCBC) and S-(1,2-dichlorovinyl)- l-cysteine (DCVC) were both cytotoxic to LLC-PK 1 cells in culture. Prior treatment of the cells with aminooxyacetic acid (AOAA), an inhibitor of the enzyme cysteine conjugate β-lyase, afforded complete protection against the toxicity at concentrations of PCBC up to 100 μM and DCVC up to 500 μM. The cytotoxicity produced by PCBC (100 μM) was time dependant with no loss of lactate dehydrogenase (LDH) into the medium being observed until 4 h after exposure, while removal of calcium from the medium prevented the toxicity. Addition of PCBC (100 μM) to LLC-PK 1 cells produced a small progressive increase in intracellular calcium ([Ca 2+] i ) from 72±6 to 126±11 nM following 10 min of exposure. At this time there was a marked cellular heterogeneity in the calcium response with some cells showing marked increases in [Ca 2+] i , while others cycled between low and high values and some just maintained basal levels. Exposure to PCBC (100 μM) for 1 h produced a more marked increase in [Ca 2+] I , 469±46 nM, with all cells responding. The elevation in [Ca 2+] i was concentration-related with increases seen at concentrations of 5 μM PCBC and above. The increase in [Ca 2+] i produced by PCBC (100 μM) was prevented by treatment with AOAA, and markedly reduced by a nominally calcium free medium or the addition of the calcium chelator EGTA. DCVC (500 μM) also markedly elevated [Ca 2+] i following exposure for 1 h, this was also prevented by AOAA and a nominal calcium free medium. These findings indicate that elevation in [Ca 2+] i produced by PCBC in renal epithelial cells, is an early event in the cascade of signalling changes leading to renal cell death. The major source of calcium appears to be from increased influx although a small component is released from intracellular stores which my trigger a stress protein response.

A supply‐response analysis of Botswana's livestock and sorghum: An error‐correction approach

This article is a supply‐response analysis of Botswana's livestock and sorghum relative to agricultural/non‐agricultural prices (terms of trade), and of capital‐labour ratio, using an error‐correction method. Aggregate capital‐labour ratio is included to measure the importance of resource endowment in particular sectors. There has been, on average, a small progressive increase in livestock terms of trade and a decline in that of sorghum. Improvements in livestock price terms of trade encourage increased livestock (cattle) supply whereas declining terms of trade reduce sorghum production. The current arable pricing policy of the government is therefore of limited potential in transforming the sub‐sector. Increases in capital‐labour ratio tend to reduce agricultural production in the Botswana economy.

Modulation of the cardiovascular defence response by low frequency stimulation of a deep somatic nerve in rats

In rats anaesthetised with alphaxalone/alphadolone, electrical stimulation in the dorsal part of the periaqueductal grey matter (PAG) produced a pressor response with tachycardia and vasodilatation in the hind limb, a pattern known as the ‘cardiovascular defence reaction’ owing to its resemblance to fear-induced hemodynamic changes. Following a 20-min period of stimulation of the peroneal nerve at 10 Hz with current intensities sufficient to recruit group II and III fibres the pressor component of the response was significantly reduced compared to control rats. The maximum decrease of the PAG-evoked pressor response was about 50% (from 32.0 ± 0.7 to 16.6 ± 5.9 mmHg). The effect lasted for between 60 and 290 min and was not correlated to baseline blood pressure changes observed after the stimulation of the nerve. In contrast, the tachycardia and hind limb vasodilator components of the defence response as well as their baseline values remained unchanged. Resting bloodpressure did not change significantly in control rats but showed a small progressive increase in stimulated rats which reached significance 90–100 min after the stimulation. These results suggest that the afferent input from hgih threshold fibres in a muscle nerve can produce a selective and long-lasting depression of the vasoconstrictor components of the midbrain-evoked cardiovascular defence response. This effect is discussed in relation to the long-lasting sympathoinhibitory effects of acupuncture-like stimulation or sustained physical exercise.

MINERAL CONTENT OF THE HUMAN SKULL DURING DEVELOPMENT

Measurements of mineral accumulation in infancy are usually referable to cartilaginous bones and yet the membranous skullbones of preterm infants are palpably soft and craniotabes is well recognised in preterm and fullterm infants. Hardening of the vault and increasing radiological density occur with growth and maturation. Calcium and magnesium contents were measured in postmortem samples of frontal bone from 108 children aged from 20 weeks gestation to 10 months of life. Samples of bone were dried, ashed and the mineral content determined by atomic absorption spectrophotometry. A small progressive increase in calcium/100 g tissue was seen in stillbirths and early neonatal deaths in the second half of gestation, 21.7g/100 g at 28 weeks to 22.6 g/100 g bone at 40 weeks (r = 0.23, p <0.02), but there was little subsequent change over the first year of life. The calcium content of many infants dying more than 7 days after birth was reduced. Calcium and magnesium contents were strongly correlated (r = 0.34, p <0.001) over the whole range of gestations studied. (Magnesium content at 40 weeks gestation = 0.307 ± 0.030 (SD), n=19). Our results are similar to previous data reported on cartilaginous long bones (femur and humerus) and suggest that mineral accretion in cartilaginous and membranous bones is similar in early development.

Vertical distributions of molecular hydrogen off the Eastern and Gulf Coasts of the United States

The vertical distributions of molecular hydrogen (H2) and carbon monoxide (CO) were determined during spiraling maneuvers from aircraft off the eastern coast of the United States and over the Gulf of Mexico. H2 was always at its lowest levels in the boundary layer, averaging about 500 parts per billion by volume (ppbv). H2 mixing ratios determined in the free troposphere were typically higher (600–700 ppbv) and often suggested a small progressive increase with altitude. Several large free‐tropospheric H2 plumes (mixing ratios as high as 1–2 parts per million by volume) were implied by the data. These H2 plumes were not always accompanied by corresponding increases in CO mixing ratios. This result is most difficult to explain when it is noted that the primary atmospheric sources for molecular H2 are considered to be combustion and photochemistry, both of which should be strong CO sources also.

The contribution of PGI2 to the effects of captopril in conscious dogs in differing states of sodium balance

There is some evidence that increased prostaglandin synthesis may mediate some of the effects of the angiotensin converting enzyme inhibitor captopril. The potential role of prostaglandin (PG)I2 in this process was assessed by measurement of changes in urinary 6-keto-PGF1 alpha excretion after captopril in eight sodium replete and depleted conscious dogs. In sodium replete animals captopril induced a small decrease in blood pressure, transient increases in effective renal plasma flow and urinary 6-keto-PGF1 alpha excretion, and progressive increases in plasma renin activity (PRA) and urinary sodium excretion. By contrast, during sodium depletion captopril induced a large decrease in blood pressure, a transient increase in effective renal plasma flow and urinary 6-keto-PGF1 alpha excretion, an early large but transient increase in PRA and small progressive increase in sodium excretion. The time course of changes after captopril suggested that increased PGI2 synthesis may contribute to the transient decrease in renal vascular resistance. The increase in PRA during sodium depletion was not associated with any change in urinary 6-keto-PGF1 alpha excretion.

Effects of bromocriptine and naloxone on plasma levels of prolactin, LH and FSH during suckling in the female rat: responses to gonadotrophin releasing hormone.

The roles of dopamine and the endogenous opiate peptides in the mediation of the inverse relationship between prolactin and gonadotrophin secretion during lactation were studied by comparing the effects of bromocriptine and naloxone on plasma levels of prolactin, LH and FSH during suckling in the female rat. The effects of exogenous gonadotrophin releasing hormone (GnRH) on the LH and FSH responses to bromocriptine and naloxone were also assessed. In control animals (saline), there was a marked fall in LH levels and a large increase in prolactin levels within 15 min of suckling. In response to GnRH (25 ng) there was a small progressive increase in LH levels reaching a maximum at 45 min. Both bromocriptine (500 micrograms) and naloxone (500 micrograms) markedly suppressed the suckling-induced prolactin surge when administered in two separate groups of animals. However, despite the bromocriptine-induced suppression of prolactin levels, there was no increase in LH levels which remained low throughout the suckling period. Naloxone (500 micrograms), however, induced a twofold increase in LH levels within 15 min suggesting that an enhanced opiate rather than dopaminergic activity may be responsible for the suppression of GnRH and hence gonadotrophin secretion during suckling. This is supported by the finding that whereas combined bromocriptine (500 micrograms) and GnRH (25 ng) treatment suppressed the suckling-induced prolactin rise and also induced only a small progressive increase in LH (similar to GnRH alone), combined naloxone (500 micrograms) and GnRH (25 ng) treatment induced a sharp sixfold increase in LH levels within 15 min while at the same time markedly suppressing prolactin levels. None of these drug treatments affected the levels of FSH.(ABSTRACT TRUNCATED AT 250 WORDS)

ADRENOCORTICAL FUNCTION IN PUBERTY Serum ACTH, Cortisol and Dehydroepiandrosterone in Girls and Boys

Abstract. Serum ACTH, Cortisol and dehydroepiandrosterone (DHEA) were determined in 200 girls and 80 boys. In girls, serum DHEA showed significant increases between all bone age groups from the youngest one, 7.5 years, to 12.5 years. A plateau was then seen up to 15.5 years of age, followed by a continuous increase to the oldest group (18.5 years). In boys, a progressive increase in DHEA was also seen from the youngest age group (8.5 years), but a period of a more rapid increase did not commence until after 12.5 years of age and it then continued to the oldest group. The level of DHEA in boys was significantly lower than in girls until the oldest group, in concert with the earlier pubertal development in girls. The importance of DHEA in initiating the early physical signs of normal puberty seems also to be different in the two sexes, since serum DHEA in girls was almost double that seen in boys, when compared according to the stage of pubic hair growth. Serum Cortisol showed a small progressive increase in girls, the concentrations postmenarche being significantly higher than premenarche. In boys, a decrease was seen up to 12.5 years of age and an increase occurred from 16.5 years onwards. In both sexes, ACTH and Cortisol levels showed an inverse but nonsignificant relationship to each other. Serum ACTH levels in the different age groups showed no significant changes.

Circular dichroism of oligosaccharides containing N-acetyl amino sugars

The circular dichroism (CD) spectra of N-acetyl amino monosaccharides and some of their methoxy derivatives, N-acetyl disaccharides, the chitin series of oligosaccharides (disaccharide through hexasaccharide), and a glycopeptide linkage compound 2-acetamido-1- N- l-aspartyl-2-deoxy-β- d-glucopyranosyl-amine (GlcNAc-Asn) were measured in order to determine which structural features are influential in determining the CD in the 190–220 nm region. The CD of the α anomers of 2-acetamido-2-deoxy- d-glucose and -galactose (GlcNAc and GalNAc, respectively) are identical to those of the corresponding equilibrium mixture whereas, for 2-acetamido-2-deoxy- d-mannose, the α anomer has a significantly more positive CD in the n-π ∗ (208–210 nm) region than does the β anomer. The CD of the α- and β-methoxy glycosides of GlcNAc and GalNAc show negative CD bands of comparable magnitude in the n-π ∗ region (209 nm) and positive CD bands of differing magnitudes in the π-π ∗ (190 nm) region. The CD spectra of β-1–4 and β-1–6 linked 2,2′-diacetamido-2,2′-dideoxyglucosyl glucoses both show a negative CD band in the n-π ∗ region and a positive band in the π-π ∗ region. The CD curves of the chitin series of oligosaccharides all exhibit a negative CD band at about 210 nm, followed by a positive band at about 192 nm. A small progressive increase in molar ellipticity per sugar residue for both the positive and negative bands with an increase in chain length is observed. The CD spectra of GlcNAc-Asn at three different pH's differ greatly from those of N-acetyl mono- and disaccharides. The CD spectrum of GlcNAc-Asn indicates a strong interaction of the exciton type between chromophores. It is concluded from the CD data that the n-π ∗ band for these compounds is not very sensitive to anomeric configuration or to disaccharide linkage of the 1–4 and 1–6 types. In contrast, the CD in the π-π ∗ region does show variation with anomeric configuration, substituent position, and linkage position. In particular, substituents at the 3 position lead to a small negative CD at 190 nm while substituents at the 4 position lead to enhanced positive CD at 190 nm.

SERUM COPPER IN NORMAL PREGNANCY IN NIGERIANS

SummarySerum copper concentrations were determined by atomic absorption spectroscopy in 288 Nigerian women comprising 212 pregnant women, 44 non‐pregnant controls and 32 postpartum women. There was a small progressive increase in serum copper during the first two trimesters to values at the upper limits of those of the nonpregnant controls. Significant increases occurred during the last trimester and persisted until the fourteenth postpartum day when the serum copper had declined to the levels observed in the control group. Both the absolute increase in serum copper and the proportion of women with increases outside the normal range were smaller than those previously reported in non‐Nigerians.

Acquisition of cohesiveness by slime mould cells prior to morphogenesis

Feeding slime mould amoebae are of very low cohesiveness. Their cohesiveness increases abruptly in the two hours following cessation of feeding. No further marked increase in cohesiveness could be detected up to and including the chemotactic aggregation stage, though there may be an additional small progressive increase.

On the changes in the main mineral constituents of Baltic herring fillets while standing in saline solutions

The purpose of this investigation was to find out what changes take place in the quantities of the ash components of Baltic herring fillets, such as alkali and alkaline earth metals, chloride and phosphate, when the fillets are kept in chloride and phosphate solutions. It was hoped that these experiments might give information on the nature of the protective effect of phosphate, as it is capable of preventing harmful changes in the myofibrillar proteins, caused by NaCl solution. The standing solutions were 3 % NaCl, 1 % Na pyrophosphate, and a solution containing both these salts. The fillets were investigated at the beginning and after a storage of 1 and 5 days. The total ash, Na, K, Mg, Ca, Cl, and P was analyzed in the fillets. The original values obtained were compared with the values given for Baltic herring and herring in the literature, as far as such data were available. The Na and Cl values of Baltic herring obtained here were somewhat lower than those reported for herring. The values obtained for K, Ca and P are somewhat high, but still the values in general agree in range with the values in the literature. Storage in the solutions increased the values of ash, even if this increase in regard to the pyrophosphate solution was only stated if the ash values were calculated for the original weights of the fillets. As far the metals were concerned, the amount of Na increased in all cases, as both chloride and pyrophosphate were used as Na salts. By contrast, the amount of K was considerably decreased, the amount of Mg less and that of Ca still less. The loss of K and Mg continued progressively for the whole standing period, while the amount of Ca returned towards the original value after a decrease during the first day. With all the metals the size of the change depended on the strength of the standing solution. The amount of chloride in the fillets was increased if storage took place in solutions containing NaCl; immigration of Cl was independent of the presence of pyrophosphate. Pyrophosphate alone extracted Cl from the fillets almost completely. The amount of phosphate in the fillets was again decreased in all the solutions, the decrease being greatest when the standing solution contained no phosphate; even then, the fillets still retained approx. 23 % of the original P. When the standing solution contained phosphate, the loss of P was small and independent of the presence of chloride. When the metals and anions investigated were calculated as equivalents, it was stated that in all cases there was an excess of cations in the fillets. During standing, changes took place in the cation excess. When standing in pyrophosphate solution alone, a small progressive increase of the cation excess was observable, while when standing in NaCl solution alone, the cation excess first decreased strongly and then partly returned towards the original value. If the solution in addition contained also pyrophosphate, the decrease was much less noticeable. In this respect the pyrophosphate has clearly inhibited the effect of NaCl, and this may be connected with the influence of pyrophosphate protecting the myofibrillar proteins.

Peroral endoscopy.

WHILE anatomic and physiologic studies cannot always be applied immediately on a clinical basis, it nevertheless is important that these observations are made and recorded. With this information available the clinician often is guided in his investigations and observations. <h3>PHYSIOLOGY OF TRACHEOBRONCHIAL TREE</h3> Although generally conceded that the nose is an effective air cleanser, particles of dust do get beyond this into the peripheral portion of the lung. This brought up the question to Hilding and Hilding¹whether there is any other air cleanser lower in the tract. They made a study of measurements on the bronchial tree using lungs removed at necropsy. They found that there is a small progressive increase in the volume of the tracheobronchial tree from the larynx to the bronchi, measuring 1.5 mm. in diameter. The increase is from 50 to 100 per cent. In this portion of the tree there does not seem to