The Development of Circadian Rhythms in Human Infants

More documents

Recommendations

Info

enquiry with regards to development in the postnatal period. Are the physiological changes in the postnatal period also consistently ordered and irreversible? Why do they not occur simultaneously? What determines their order? Can the speed of change be altered or entrained by changes in routine, feeding, lighting etc? What are the implications for programming of adult disease, future morbidity and mortality? Who is more vulnerable and why? What is the relationship between immature physiological state and social deprivation? How is this relationship, if present, mediated? Is it connected with ‟chaotic‟ lifestyles, nutrition or exposure to tobacco smoke? As a priority it would be interesting to further explore the following - � The physiological systems in infants known to be delayed in maturation e.g. IUGR, Twins, deprived groups, ethnic minority comparisons, premature infants, infants at risk of developmental disability/SIDS. Future work might include: � Refinement of definition of maturity of circadian rhythms in melatonin and cortisol secretion, with possible collection of data for leptin, ghrelin, growth hormone which also have robust circadian rhythms � Development of potential markers of at risk infants for common infant morbidities and who are at risk of mortality (e.g. develop fetal HRV doppler flow studies inutero; buccal swab measurements of melatonin/cortisol/other hormones of growth factors/ peripheral gene cycles). 242
� Maximise technique for measuring cycling gene expression in adults and infants from buccal swabs – do experiments in lab controlled setting to dampen down „noise‟ vs. home studies � Study of the effects of different infant care routines on infant physiology (Gina Ford vs. demand feeding and infant led bed times, places of sleep) using anthropological methods � More detailed sleep work to define the ontogeny of sleep in first postnatal months (possibly using behavioural observation and portable PSG) � Examine further effect of illness and social circumstances on physiology � Further work on infant separation from mother-infant dyad and the consequences of this on infant physiology Directing our scientific enquiry into areas that simultaneously include topics of scientific value, with the search for answers to questions parents want to know will allow the continuation of researcher-carer partnerships which were invaluable in this project. Refining our knowledge of postnatal physiology and development will increase our understanding of the implications of physiological malfunction and delayed maturation. This may help contribute to the understanding of foetal origins of adult diseases such as those included in Syndrome X (Diabetes mellitus, Coronary Heart Disease, Hypertension- all associated with Obesity) and neurodevelopmental conditions which have a disruption of circadian rhythmicity as a prominent feature. Finally it may contribute the final pieces of the jigsaw puzzle known as the disease entity Sudden Infant Death Syndrome. The work is labour intensive and detailed but the privilege of working hand in hand with mothers and fathers of newborn infants 243
Page 1 and 2:
The Development of Circadian Rhythm
Page 3 and 4:
Table of Contents LIST OF FIGURES .
Page 5 and 6:
7.1 Analysis of infant sleep measur
Page 7 and 8:
List of Figures Figure 1.1 - Diagra
Page 9 and 10:
List of Tables Table 3.1 - Descript
Page 11 and 12:
1 Introduction Happiness is not a m
Page 13 and 14:
Each of these independently is impo
Page 15 and 16:
There is general agreement, that al
Page 17 and 18:
Summary 1. Development encompasses
Page 19 and 20:
Figure 1.1 - Diagram illustrating c
Page 21 and 22:
A phase shift is used to describe a
Page 23 and 24:
1.4 Ontogeny in Human Infants Well
Page 25 and 26:
1.5.2 Circadian Rhythms in Temperat
Page 27 and 28:
1.5.4 Factors affecting Temperature
Page 29 and 30:
1.6 Melatonin (Reviewed in Cardinal
Page 31 and 32:
mechanism by which this occurs is n
Page 33 and 34:
It is at this time that infant slee
Page 35 and 36:
1.7 Cortisol Cortisol is a hormone,
Page 37 and 38:
1.7.3 Circadian pattern of Cortisol
Page 39 and 40:
In a separate study, Weerth et al u
Page 41 and 42:
Summary 1. Cortisol is crucial to a
Page 43 and 44:
NREM sleep has 4 stages. It occupie
Page 45 and 46:
1.8.1 Functions of Sleep The functi
Page 47 and 48:
1.8.3 Ontogeny of Sleep in Infants
Page 49 and 50:
Sleep can clearly be used as marker
Page 51 and 52:
For the purpose of this study, the
Page 53 and 54:
Summary 1. Sleep is defined by lack
Page 55 and 56:
Overall the SCN generates signals (
Page 57 and 58:
Figure 1.2 - The mammalian circadia
Page 59 and 60:
1.9.3 Molecular Components of the C
Page 61 and 62:
Figure 1.3 - Mechanisms from SCN to
Page 63 and 64:
1.9.7 Melatonin and Clock Melatonin
Page 65 and 66:
The links between the central clock
Page 67 and 68:
Chapter 2 Methods
Page 69 and 70:
There were strict inclusion and exc
Page 71 and 72:
This personal contact on the postna
Page 73 and 74:
2.1.3 Home monitoring visits The fi
Page 75 and 76:
2.1.4 Further monitoring informatio
Page 77 and 78:
Core body temperature was taken sim
Page 79 and 80:
2.3 Collection of urine samples Pai
Page 81 and 82:
were read against air at 429 nm aft
Page 83 and 84:
allowed the display and comprehensi
Page 85 and 86:
2.8.1 RNA preparation and cDNA synt
Page 87 and 88:
In total three methods were trialle
Page 89 and 90:
2.11 Statistical methods For compar
Page 91 and 92:
test that each infant‟s height an
Page 93 and 94:
Power calculation Sample size: Fift
Page 95 and 96:
3 Results 3.1 Recruited subjects an
Page 97 and 98:
predominantly affluent areas of the
Page 99 and 100:
Birth history and past medical hist
Page 101 and 102:
3.1.3 Socioeconomic demographics of
Page 103 and 104:
her best friend losing her battle w
Page 105 and 106:
Sleep environment of infants All mo
Page 107 and 108:
Summary 1. This study had higher ra
Page 109 and 110:
4 Results 4.1 Core body temperature
Page 111 and 112:
Degrees Celsius 36.70 36.60 36.50 3
Page 113 and 114:
11-13 weeks There is no significant
Page 115 and 116:
Core body temperature (degrees Cels
Page 117 and 118:
Number of infants 10 8 6 4 2 0 7 8
Page 119 and 120:
Mean minimum rectal temperature in
Page 121 and 122:
Mean minimum rectal temperature in
Page 123 and 124:
Figure 4.7 shows the changes in the
Page 125 and 126:
Chapter 5 Result
Page 127 and 128:
4 or 6 hourly samples. Circadian rh
Page 129 and 130:
Figure 5.1 - Distribution of mean n
Page 131 and 132:
5.1.2 Emergence of diurnal rhythm f
Page 133 and 134:
Figure 5.3 - Histogram showing dist
Page 135 and 136:
Figure 5.4 - Changes in night time
Page 137 and 138:
Night-day difference in melatonin s
Page 139 and 140:
Summary 1. There is an increase in
Page 141 and 142:
6 Results DESCRIPTION OF THE URINAR
Page 143 and 144:
Page 145 and 146:
6.1.2 Emergence of diurnal rhythm f
Page 147 and 148:
Figure 6.3 - Histogram showing dist
Page 149 and 150:
Page 151 and 152:
Cortisol values were corrected to a
Page 153 and 154:
6.1.4 Relationship between night an
Page 155 and 156:
Chapter 7 Results
Page 157 and 158:
Mean Length of Sleep/ Wake Bouts Th
Page 159 and 160:
Sleep parameters were recorded as m
Page 161 and 162:
7.3 Development of infant sleep rel
Page 163 and 164:
Figure 7.2 - Changes in infant slee
Page 165 and 166:
Figure 7.4 - Changes in percentage
Page 167 and 168:
Figure 7.5 - Changes in infant frag
Page 169 and 170:
Figure 7.7 - Changes in number of m
Page 171 and 172:
Figure 7.9 - Changes in the percent
Page 173 and 174:
Sleep efficiency (%) 100.0 90.0 80.
Page 175 and 176:
Chapter 8 Results
Page 177 and 178:
Considering only those weeks of mea
Page 179 and 180:
8.2 Description of peripheral gene
Page 181 and 182:
18:30 hours 0.9927; 01:00 ours 1.01
Page 183 and 184:
The weeks after temperature maturat
Page 185 and 186:
Further peripheral gene graphical r
Page 187 and 188:
Raw data points are represented by
Page 189 and 190:
H3f3b/Gap H3f3b/Gap H3f3b/Gap H3f3b
Page 191 and 192:
8.3 Detailed gene expression analys
Page 193 and 194:
Summary 1. H3f3b was selected as ge
Page 195 and 196:
9 Results FACTORS AFFECTING SLEEP A
Page 197 and 198:
Care and infant related factors �
Page 199 and 200:
Table 9.3 - Effect of family occupa
Page 201 and 202: * Class 7 used as reference group
Page 203 and 204: Table 9.6 - Effect of measured infa
Page 205 and 206: Summary: 1. A mature physiological
Page 207 and 208: 10 Results 10.1 Circadian rhythms -
Page 209 and 210: value of above 0.5 for R squared wa
Page 211 and 212: Table 10.1 - Temporal relationship
Page 213 and 214: Chapter 11 Discussion
Page 215 and 216: � What if any are the factors whi
Page 217 and 218: 11.1 Physiological development - ag
Page 219 and 220: There are other proven factors whic
Page 221 and 222: drawbacks of the spread of data - a
Page 223 and 224: presented in table 6.1 do not have
Page 225 and 226: separate methods were applied to th
Page 227 and 228: significant. Sleep latency was cons
Page 229 and 230: The function of sleep in developmen
Page 231 and 232: Melatonin secretion was higher on n
Page 233 and 234: In this study sleeping in the same
Page 235 and 236: Timing of sleep maturation was diff
Page 237 and 238: systematic, ordered developmental p
Page 239 and 240: individual gene plots that provide
Page 241 and 242: temperature recording devices adapt
Page 243 and 244: Both melatonin and cortisol rhythms
Page 245 and 246: Extension of this period of monitor
Page 247 and 248: Second, we demonstrated the gene of
Page 249 and 250: Cortisol and melatonin Slope based
Page 251: Summary and Future work This study
Page 255 and 256: “There is a science of infant car
Page 257 and 258: References
Page 259 and 260: Bajanowski, T., Vege, Å., Byard, R
Page 261 and 262: Chamley, C.A., Carson P, Randall D,
Page 263 and 264: Frank, M.G., Heller, H.C., 2003. Th
Page 265 and 266: intrahypothalamic administration of
Page 267 and 268: Mirmiran, M. & Ariagno, R.L., 2000.
Page 269 and 270: Rawson, D., Petersen, S.A., Wailoo,
Page 271 and 272: Stokkan, K.A., Yamazaki, S., Tei, H
Page 273 and 274: Winter, J.S.D., 1985. The adrenal c
show all

The Development of Circadian Rhythms in Human Infants

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?