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Biomedical subjects

J J McKenna

Publications and source records attributed to J J McKenna.

At least 19 recordsLinked to original sources
PubMed2002

Comparative study of age, sex, illness profile, between suburban, rural and central urban population in general practice.

UNLABELLED: To investigate the differences between rural suburban and central urban patterns in General Practise, in terms of Patient age, sex and illness profiles, in Winter. Using a laptop computer, all relevant patient parameters were entered during the surgery consultation as each patient attended. The totals for each parameter were subsequently computed and using the Microsoft Excel program comparative pie charts for urban and rural categories were compiled, in percentage terms. SETTING: Cork. In the rural area 60% of those attending were male, while in the urban area only 43% were male. There were 2.75 times more people over 65 years old attending the urban surgery. However there were 80% more under 14 year olds and 43% more in the 15 to 64 year age group attending the rural surgery.

Adolescent↗
PubMed1998

Apnea and periodic breathing in bed-sharing and solitary sleeping infants.

Mother-infant bed sharing, compared with the solitary sleeping condition, has recently been associated with several physiological and behavioral effects. Because the physiological effects of bed sharing may also include respiratory changes, we compared the incidence of central and obstructive apneas and periodic breathing in bed-sharing and solitary sleeping infants. Twenty routinely bed-sharing mother-infant pairs and fifteen routinely solitary sleeping pairs slept for 3 nights in a sleep laboratory. After an initial adaptation night, each pair spent 1 night bed sharing and 1 night in solitary sleep in random order. Apnea and periodic breathing were scored from polysomnographic recordings. The frequency of central apnea was significantly increased on the bed-sharing night, compared with the solitary night, regardless of routine sleeping arrangement. There were significantly fewer obstructive apneas on the bed-sharing night than on the solitary night, but only in routinely solitary sleeping infants. In both groups, there was a significantly higher frequency of periodic breathing events on the bed-sharing night than on the solitary night. These findings demonstrate that the bed-sharing environment can have a significant impact on respiratory control in the infant. Evidence is also presented to suggest that routine bed sharing may result in subtle neurophysiological and/or developmental differences in infants.

Female↗
PubMed1997

Bedsharing promotes breastfeeding.

OBJECTIVE: Because breastfeeding is thought to be protective against sudden infant death syndrome (SIDS), environmental or child care factors that promote breastfeeding might reduce infant vulnerability to SIDS. The effect of mother-infant bedsharing on nocturnal breastfeeding behavior was studied in 20 routinely bedsharing and 15 routinely solitary sleeping Latino mother-infant pairs when the infants were 3 to 4 months old. METHODOLOGY: All pairs were healthy and exclusively breastfeeding at night. The videotape portion of all-night laboratory polysomnographic studies was used for the analyses. For each pair, an adaptation night was followed by one night each of bedsharing and solitary sleeping. RESULTS: The most important finding is that when tested in their usual sleeping conditions, routinely bedsharing infants breastfed approximately three times longer during the night than infants who routinely slept separately: this reflected a two-fold increase in the number of breastfeeding episodes and 39% longer episodes. Breastfeeding was also facilitated on the bedsharing night relative to the solitary night within the routinely bedsharing group: the number and total duration of breastfeeding episodes were significantly larger on the bedsharing night. CONCLUSIONS: We suggest that, by increasing breastfeeding, bedsharing might be protective against SIDS, at least in some contexts. Furthermore, maternal reproductive physiology could be impacted because nursing frequency affects ovulation. This is the first study to directly measure nocturnal breastfeeding behavior in any cultural group.

Adult↗
PubMed1994

Sleep and arousal, synchrony and independence, among mothers and infants sleeping apart and together (same bed): an experiment in evolutionary medicine.

Although solitary sleeping in infancy is a very recent custom, limited to Western industrialized societies, and most contemporary people practice parent-infant co-sleeping, virtually all laboratory research on sleep in human infants assumes that solitary infant sleep is the normal and desirable environment. We have used evolutionary and developmental data to challenge this view. We suggest that co-sleeping provides a sensory-rich environment which is the more appropriate environment in which to study infant sleep. In addition, two preliminary, in-laboratory, polygraphic investigations of mother-infant co-sleeping are reported in normal infants, within the peak age range for sudden infant death syndrome (SIDS). Five mother-infant pairs co-slept one night in the first study; in the second, three additional pairs slept separately for two nights and co-slept the third consecutive night. The results suggest that co-sleeping is associated with enhanced infant arousals and striking temporal overlap (synchronicity) in infant and maternal arousals, and that, possibly as a result, co-sleeping mothers and infants spend more time in the same sleep stage or awake condition. The implications of the hypothesis and preliminary results for research on the normal development of infant sleep and on SIDS are discussed.

Female↗
PubMed1993

Infant-parent co-sleeping in an evolutionary perspective: implications for understanding infant sleep development and the sudden infant death syndrome.

Evidence suggests that infant-parent co-sleeping represents the species-wide pattern of sleep in which human infant physiology evolved. The hypothesis evaluated in this manuscript is that the co-sleeping environment may foster development of optimal sleep patterning in infants and confer other benefits, including reducing the risk of the sudden infant death syndrome (SIDS). These postulations by McKenna are considered from different perspectives by the coauthors. Using evolutionary, cross-species, crosscultural, physiological and behavioral data, our objective was to present a conceptual framework for assessing the developmental consequences of solitary sleeping and infant-parent co-sleeping.

Adult↗
PubMed1990

Sleep and arousal patterns of co-sleeping human mother/infant pairs: a preliminary physiological study with implications for the study of sudden infant death syndrome (SIDS).

The prevailing research design for studying infant sleep erroneously assumes the species-wide normalcy of solitary nocturnal sleep rather than a social sleeping environment. In fact, current clinical perspectives on infant sleep, which are based exclusively on studies of solitary sleeping infants, may partly reflect culturally induced rather than species-typical infant sleep patterns which can only be gleaned, we contend here, from infants sleeping with their parents--the context within which, and for well over 4 million years, the hominid infant's sleep, breathing, and arousal patterns evolved. Our physiological study of five co-sleeping mother-infant pairs in a sleep lab is the first study of its kind to document the unfolding sleep patterns of mothers and infants sleeping in physical contact. Our data show that co-sleeping mothers and infants exhibit synchronous arousals, which, because of the suspected relationship between arousal and breathing stability in infants, have important implications for how we study environmental factors possibly related to some forms of the sudden infant death syndrome (SIDS). While our data show that co-sleeping mothers and infants also experience many moments of physiological independence from each other, it is clear that the temporal unfolding of particular sleep stages and awake periods of the mother and infant become entwined and that on a minute-to-minute basis, throughout the night, much sensory communication is occurring between them. Our research acknowledges the human infant's evolutionary past and considers the implications that nocturnal separation (a historically novel and alien experience for them) has for maternal and infant well-being in general and SIDS research strategies in particular.

Adult↗
PubMed1988

A method of orientation of skull and camera for use in forensic photographic investigation.

The ability to obtain accurate superimposition of the image of the teeth from ante- and post-mortem dentitions is a prerequisite of photographic superimposition. A prototype skull and camera holder is described that enables this to be achieved quickly and simply. The position of the skull relative to the attitude of the face in the photograph can then be documented and hence reproduced as required.

Cephalometry↗
PubMed1986

Unmasking AIDS: chemical immunosuppression and seronegative syphilis.

In both African AIDS populations and homosexual populations outside of Africa, a high incidence of syphilis and multiple exposures to infectious diseases results in frequent, often abusive use of antibiotics. Epidemiological evidence exists for chemical immunosuppression resulting from antibiotics and other prescribed and recreational drugs prior to the current AIDS crisis. Analysis and review of literature is given on the effects of subcurative doses of antibiotics masking and distorting the expression of secondary and tertiary syphilis. A high incidence of seronegative syphilis is found in Africa and compares with Western reports of seronegativity and persistence of treponemes despite adequate antibiotic therapies. Late latent and tertiary syphilis produce symptoms and immunosuppression comparable to that seen in the current AIDS crisis. Screening procedures instituted for a group of gay men with AIDS and AIDS related conditions is revealing evidence of chemically immunosuppressed syphilis as a factor in AIDS. Key words: AIDS, immunosuppression, syphilis, chemical immunosuppression, seronegativity, immunosuppressive sera, etiology of AIDS.

AIDS-Related Complex↗
PubMed1986

Prolactin levels in hypothyroid and euthyroid infants during the first week of life.

A radioimmunoassay (RIA) procedure was devised for the estimation of PRL in eluates of dried whole blood from filter paper. Levels of PRL were measured in newborn blood obtained during the first week of life from 530 infants of normal birthweight (greater than 2500 g) with normal T4 values, 114 infants of normal birthweight with low T4 values (T4 less than 6.0 micrograms/dl), 47 infants with congenital hypothyroidism, 57 infants of low birthweight (less than 2500 g) with normal T4 values, and 114 infants of low birthweight with low T4 values. Examination of PRL concentrations among comparably aged infants from the various groups revealed that the mean PRL values of the hypothyroid group were consistently greater than those of any of the other groups of infants regardless of the mean T4 levels. With the exception of the hypothyroid infants, the groups with both the lowest mean T4 concentrations and mean body weights also had the lowest mean PRL values.

Birth Weight↗
PubMed1986

Establishment of a large collection of extracted teeth for research.

A collection of over 14,000 teeth extracted at the Prince Philip Dental Hospital since 1982 has been organized and catalogued on a computerized database management system. The computer catalogue provides, for each tooth in the collection, information on the age and sex of the patient, and the date of extraction and condition of the tooth. The catalogue can be searched according to any combination of the descriptive variables in the database record. Researchers, including visiting scientists, can borrow teeth from the central "tooth library" on a temporary or permanent basis. Further information on particular teeth (e.g. patient's medical and dental histories, dental radiographs) can be obtained from patients' charts. Establishment of this collection has greatly facilitated the work of researchers in clinical dentistry, dental anatomy, and dental anthropology.

Humans↗
PubMed1984

A method of matching skulls with photographic portraits using landmarks and measurements of the dentition.

A method of matching and identifying skulls to family snapshots or passport photographs is described. The technique depends on the recovery of teeth, particularly the maxillary anterior teeth, with the skull and the availability of an antemortem photograph showing those teeth. Measurements of the anterior dentition of unidentified skulls are used to determine the magnification factor necessary for the preparation of life-sized transparencies of photographs. Superimposition of dental landmarks in these transparencies leads to correlation of further cranial features, thus enabling a successful positive identification. Suggestions are made for a system of identification based on assessment of visible features of the dentition.

Adolescent↗
PubMed1980

Radioimmunoassay of thyrotropin and thyroxine in dried blood by use of Staphylococcus aureus containing "protein A.".

We report the use of Staphylococcus aureus rich in protein A as an immunoadsorbent in the radioimmunoassay of thyrotropin and thyroxine in blood collected from newborn infants and dried on filter paper. The procedures for thyrotropin and thyroxine, which differ mainly with respect to concentration and volume of the Staphylococcus aureus suspension, are reliable, rapid, and technically simple. The ease of this method, coupled with its dependability, offers certain advantages over some of the commonly used techniques of separation, and therefore it provides a unique approach to measurement of these analytes in laboratory screening programs for neonatal hypothyroidism.

Blood Specimen Collection↗