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Biomedical subjects

M Graff

Publications and source records attributed to M Graff.

14 recordsLinked to original sources

Genomic basis of developmental defects of enamel and sex-specific effects.

We conducted a multi-ancestry genome-wide association study (GWAS) of developmental defects of enamel (DDE) in the primary dentition among 6,061 U.S. preschool-aged children (3-5 years). We investigated four DDE phenotypes (demarcated opacities, diffuse opacities, hypoplastic defects, and a combined DDE trait) leveraging main-effect models, joint gene-sex interaction testing (2df), and sex-stratified analyses. SNP-based heritability for the combined DDE trait was estimated at 20%, with concordance analyses robustly supporting a genetic etiology. We identified 39 unique genome-wide significant loci (P<5&#xd7;10 ), with five surpassing a study-wide Bonferroni-corrected statistical significance criterion (P<1.25&#xd7;10 9), including Y RNA and ALDH1A1. The main-effect GWAS identified 20 loci, including HBS1L and MYB, genes regulating hematopoiesis with plausible roles in amelogenesis. Joint test and sex-stratified analyses revealed 19 additional loci, including ALDH1A1, TENM2, and DLGAP2, demonstrating sex-specific heterogeneity. Nineteen loci exhibited sex-specific differences after Bonferroni correction (P<2x10-3), including genes involved in retinoic acid signaling (ALDH1A1), odontogenesis (TENM2), and neurodevelopment (DLGAP2, CDH10). Pathway enrichment highlighted ectodermal and synapse organization networks, suggesting shared etiological mechanisms between DDE and systemic conditions like neurofibromatosis and autism spectrum disorder. Notably, no locus generalized in an external GWAS of permanent dentition DDE, underscoring fundamental biological differences in the genetic architectures governing primary versus permanent enamel formation. Crucially, a comprehensive cross-trait pleiotropy lookup against early childhood caries (ECC) revealed no shared genetic architecture, supporting the notion that the established clinical and epidemiological association between DDE and ECC is likely driven by structural defects increasing caries lesion susceptibility rather than genetic pleiotropy. By integrating gene-sex interaction testing, this study offers novel insights into the complex, sexually dimorphic genetic etiology of DDE and augments the biological evidence base that can support the development of precision pediatric dentistry.

developmental defects of enamel

Undetected apnea and bradycardia in infants.

Despite routine monitoring, a number of prolonged apneic and bradycardic episodes were undetected in a group of infants in the neonatal intensive care unit (NICU). Sixty-one infants were evaluated by 12-hour pneumocardiograms at a post-conceptional age of 35 +/- 3 (SD) weeks. Nursing documentation failed to detect 11 infants with prolonged apnea and bradycardia. Three of these infants were not detected in spite of increased awareness following in-service education. Such a lack of documentation may lead to improper medical management of infants at risk for pathologic apnea and suggests the need for more accurate documentation at the time of discharge.

Apnea

The four-channel pneumogram in infants with recurring apneas and bradycardias.

The two-channel pneumocardiogram (PCG) is frequently used for evaluating infants at risk for infantile apnea. In this study, the two-channel PCG failed to identify a significant number of symptomatic infants that were diagnosed by a four-channel pneumocardiogram. Nine infants suffering from either apparent life-threatening events (ALTE) or persistent apnea of prematurity were evaluated with two- and four-channel PCGs. The four-channel PCGs consisted of the standard two-channel evaluations, ECG and impedance pneumography, expanded by the addition of pulse oximetry and nasal thermistry. The PCGs were evaluated in a blinded manner by three trained observers. Each PCG was evaluated in both the two- and four-channel mode. A PCG was considered abnormal when any of the following was present: (1) a heart rate deceleration greater than one third of the baseline and lasting more than 8 seconds, (2) an apneic pause, either by impedance or by airflow, of greater than 20 seconds, (3) evidence of obstructive apnea less than 20 seconds but associated with cardiac deceleration, and (4) evidence of oxygen desaturation below 85% and lasting more than 8 seconds. All nine of the infants studied had recurrent apneic episodes at home. The four-channel PCGs were abnormal in all of the infants studied, whereas only four of the two-channel PCGs were abnormal (P less than .02). In this population, over 50% of the infants were incorrectly evaluated by the standard two-channel PCG and correctly identified by the four-channel PCG.

Apnea

Home-like architectural features of residential environments.

Adults who had no experience in the area of mental retardation viewed slides of residential settings, five providing housing for people with mental retardation, and rated their "home-likeness" (1 = home-like, 5 = institutional). Of 55 two-way comparisons, the mean home-likeness ratings of 48 such pairs differed significantly from one another. A .98 log-linear correlation was found between number of residents in a given facility and institutional ratings. Of 26 features of living rooms studied in detail, furniture position, lighting type, and lighting flexibility were highly correlated with home-likeness, whereas building code-specific features and seating type were minimally related to home-likeness.

Adult

Prenatal lidocaine and the auditory evoked responses in term infants.

We examined the effects of maternal lidocaine hydrochloride anesthesia on the brain-stem auditory evoked responses (BAERs) in neonates born by cesarean delivery. Sixteen term neonates were enrolled in the study. Eight neonates were delivered by cesarean section following lidocaine anesthesia, and eight were delivered by spontaneous vaginal delivery without maternal anesthesia. A BAER was obtained on all of the neonates on the first day of life. A significant delay was noted in the central neural component of the BAER at 90 dB. The wave I through V interpeak latency for both ears was noted to be 5.3 ms for the neonates exposed to lidocaine and 4.9 ms for the controls.

Anesthesia, Epidural

Prevention of hypoxia and hyperoxia during endotracheal suctioning.

A new suction catheter, designed to deliver alternately oxygen or suction, prevented episodes of hypoxia and hyperoxia in a group of infants during endotracheal suctioning. Twenty infants received both conventional endotracheal suctioning and suctioning by the new catheter. The infants had a maximal change from a presuctioning transcutaneous oxygen (PtcO2) of 12 +/- 8 torr and required 3.1 +/- 2 min to regain their presuctioning oxygenation level compared to a maximal change of 21 +/- 10 torr (p less than .05) and a stabilization time of 5.3 +/- 2.6 min (p less than .05) in the conventionally treated group. Three study infants experienced an abnormal PtcO2 (either less than 40 or greater than 90 torr), while 13 control infants suffered these abnormalities (p less than .01). The use of this new suction device effectively reduced the exposure of this group of infants to episodes of aberrant oxygen states and allowed for a shorter recovery time.

Blood Gas Monitoring, Transcutaneous

Transcutaneous bilirubinometry. III. Dermal bilirubin kinetics under green and blue light phototherapy.

Using the transcutaneous bilirubinometer, we studied the response of cutaneous bilirubin to different colors of light during phototherapy. Three groups of ten infants were exposed to blue, green, and blue-green lights at a mean postnatal age ranging from 50 to 77 hours. Patched areas served as controls. Every 15 minutes during four hours of phototherapy, we obtained simultaneous measurements from exposed and covered areas. After the onset of phototherapy, transcutaneous bilirubinometer values from the covered areas in all groups remained stable. The overall rate of bleaching was lowest in the green light group and highest in the blue-green combination group. In this group of infants, green light appeared to enhance the effectiveness of blue light in reducing dermal bilirubin concentrations as measured by the transcutaneous bilirubinometer.

Bilirubin

Effect of caffeine on pneumogram and apnoea of infancy.

We studied the efficacy of caffeine in improving pneumogram abnormalities and relieving clinically important apnoea of infancy in 23 infants. After obtaining a 12 hour pneumogram we administered caffeine citrate in a loading dose of 20 mg/kg followed by 5 mg/kg once daily. This dose achieved a trough caffeine blood concentration of 9.6 (SD 2.0) micrograms/ml. A repeat pneumogram performed seven to 10 days after the first pneumogram showed a significant reduction in the number of short and prolonged attacks of apnoea as well as in the per cent periodic breathing and apnoea density. Episodes of prolonged apnoea disappeared in all infants after administration of caffeine and in 11 infants all pneumogram abnormalities resolved. This improvement in the results of pneumograms was associated with resolution of clinically important apnoea requiring intervention. Caffeine was administered for 3.4 (SD 1.3) months and was well tolerated by all except two infants. We conclude that treatment with caffeine is helpful in preventing attacks of apnoea that require intervention, and improvement in the results of pneumograms after administration of caffeine predicts this favourable response.

Apnea

Nosocomial fungal infection during hospital renovation.

Nosocomial fungal pulmonary infections (Zygomycetes, Aspergillus sp.) developed in two premature infants in a special care unit (SCU) adjacent to an area of renovation. Inspection showed that inadequate barriers permitted the passage of airborne particles between the two areas, and cultures confirmed a significantly higher (p less than or equal to 0.05) density of mold spores in the SCU (0.88 cfu per hour per settling plate) compared to a construction-free comparison area (0.22 cfu per hour per settling plate). The major source of mold was the dust above the hospital's false ceiling. In another construction area, imperious barriers were shown to effectively restrict the dispersal of mold. Our experience adds Rhizopus to Aspergillus as a possible cause of construction-related nosocomial infection. Sporadic episodes will continue to occur until the hazards of renovation are appreciated and effective preventive measures are routinely instituted.

Air Microbiology

Paratesticular liposarcoma.

The fifteenth reported case of paratesticular liposarcoma is presented, together with a review of the literature. The prognostic and therapeutic implications of this particular neoplasm are discussed.

Adult