A prototype rapid dual energy X-ray absorptiometry (DEXA) system can predict the CT composition of beef carcases.

The development of a novel rapid dual energy X-ray absorptiometry (DEXA) system provides the opportunity to improve measurement of beef carcase composition. A prototype rapid DEXA system was built in a shipping container to scan 51 beef carcases selected for a wide range in weight and fatness. One side of each carcase was spray chilled and the other conventionally chilled overnight before being quartered for DEXA scanning and then being cut into 16 pieces for CT scanning to determine carcase composition. Spray chilling did not impact DEXA prediction of CT composition, with the DEXA system describing 89%, 95%, and 87% of the variation in beef carcase CT lean %, fat % and bone %, with a root mean square error of prediction of 2.31 lean %, 2.15 fat %, and 1.12 bone % units. These results demonstrate that the novel rapid DEXA system has excellent capacity to predict CT composition in beef carcases.

Calibration of an on-line dual energy X-ray absorptiometer for estimating carcase composition in lamb at abattoir chain-speed.

This experiment assessed the ability of an on-line dual energy x-ray absorptiometer (DEXA) installed at a commercial abattoir to determine carcase composition at abattoir chain-speed. 607 lamb carcases from 7 slaughter groups were DEXA scanned and then scanned using computed tomography to determine the proportions of fat (CT fat%), lean (CT lean%), and bone (CT bone%). Data between slaughter groups were standardised relative to a synthetic phantom consisting of Nylon-6. Models were then trained within each dataset using hot carcase weight and DEXA value to predict CT composition, and then validated in the remaining datasets. Results from across-dataset validation tests demonstrated excellent precision for predicting CT fat%, with RMSE and R2 values of 1.32 and 0.89, compared to values of 1.69 and 0.69 for CT lean%, and 0.81 and 0.68 for CT bone% which had less precision. Accuracy across datasets was also robust, with average bias values of 0.66, 0.83, and 0.51 for CT fat%, lean%, and bone%.

Sizing alpha emitting particles of aged plutonium on personal air sampler filters using CR-39 autoradiography.

Methods have been developed to assess the size distribution of alpha emitting particles of reactor fuel of known composition captured on air sampler filters. The sizes of uranium oxide and plutonium oxide particles were determined using a system based on CR-39 solid-state nuclear track detectors. The CR-39 plastic was exposed to the deposited particles across a 400 microm airgap. The exposed CR-39 was chemically etched to reveal clusters of tracks radially dispersed from central points. The number and location of the tracks were determined using an optical microscope with an XY motorised table and image analysis software. The sample mounting arrangement allowed individual particles to be simultaneously viewed with their respective track cluster. The predicted diameters correlated with the actual particle diameters, as measured using the optical microscope. The efficacy of the technique was demonstrated with particles of natural uranium oxide (natUO2) of known size, ranging from 4 to 150 microm in diameter. Two personal air sampler (PAS) filters contaminated with actinide particles were placed against CR-39 and estimated to have size distributions of 0.8 and 1.0 microm activity median aerodynamic diameter (AMAD).

Perpetrators of abusive head trauma: a comparison of two geographic populations.

BACKGROUND: Abusive head trauma accounts for significant morbidity and mortality in infants. We compared a Southern population of victims with those in a previous study of a Western population, which found that men, particularly fathers and mothers' boyfriends, are the most common perpetrators. METHODS: All cases of child abuse identified in a teaching hospital were prospectively reviewed for cases of abusive head trauma, and the perpetrators were identified. RESULTS: Of the 76 cases of head trauma identified, 27 met the criteria for the study. The demographics of the perpetrators closely match those of the Western group. Men are the predominant perpetrators, with fathers committing 45% and boyfriends 25% of these injuries. CONCLUSIONS: Despite the differences in study design and population demographics, men are the most common perpetrators of abusive head trauma in both populations.

Child abuse and forensic pediatric medicine fellowship curriculum statement.

Physicians have been involved in the diagnosis and treatment of victims of child abuse and neglect for more than 35 years. In the past decade, a cadre of physicians has developed extensive expertise in the field. Now, physicians are requested for expert consultation by medical, investigative, and legal colleagues. As the field advances, it has become necessary to train more physicians in the field of child abuse and forensic pediatrics as well as to standardize the curricula of the existing fellowships. A joint working group of the American Academy of Pediatrics Section on Child Abuse and Neglect and the Forensic Pediatrics Physician Leadership Group convened to develop a curriculum for medical fellowships in child abuse and neglect. The authors present the model curriculum developed by this group.

Abusive head trauma: the relationship of perpetrators to their victims.

OBJECTIVE: Abusive head trauma is the most common cause of morbidity and mortality in physically abused infants. Effective prevention requires the identification of potential perpetrators. No study has specifically addressed the relationship of the perpetrators of abusive head trauma ("shaken baby syndrome") to their victims. The objectives of this study were to identify the abusers and their relationship to victims in these cases. METHODS: We reviewed the medical charts of 151 infants who suffered abusive head trauma to determine the perpetrator of the abuse. Caretakers were classified by level of certainty: confession to the crime, legal actions taken, or strong suspicion by the staff. The relationship of abusers to victims was analyzed. RESULTS: Male victims accounted for 60.3% of the cases. Twenty-three percent of the children died, although death rates for boys and girls did not vary significantly. Male perpetrators outnumbered females 2.2:1, with fathers, step-fathers, and mothers' boyfriends committing over 60% of the crimes. Fathers accounted for 37% of the abusers, followed by boyfriends at 20.5%. Female baby-sitters, at 17.3%, were a large, previously unrecognized group of perpetrators. Mothers were responsible for only 12.6% of our cases. All but one of the confessed abusers were with the child at the time of onset of symptoms. CONCLUSIONS: Our data suggest male caretakers are at greater risk to abuse infants. Baby-sitters are a concerning risk group, because they represent a significant proportion of abusers, and they more easily escape prosecution. In addition, no prevention efforts have been directed at baby-sitters. These statistics could help change the focus of efforts to prevent abusive head trauma.

Syphilis in infants and young children.

Syphilis is a disease very much on the rise in certain populations in this country. It has reached epidemic proportions in some areas. This trend should be a concern to physicians caring for children in the United States. Rates of congenital syphilis are continuing to rise. Certainly, the poor prenatal care received by many women is inhibiting our ability to prevent congenital syphilis. All infants should have a maternal test for syphilis clearly documented before hospital discharge. In the event that maternal history of length of disease or treatment cannot be documented, the infant should be treated with a full course of antibiotics. In addition, all symptomatic infants should be treated and followed to ascertain falling antibody titers. Acquired syphilis should be suspected in any child with either a positive test for syphilis or symptomatic syphilis in whom evidence for congenital syphilis cannot be documented. Sexual abuse must be strongly suspected even in the absence of disclosure, and the case must be reported to local child protective services. Adequate treatment and follow-up must be assured. Clinicians should refamiliarize themselves with the many and varied presentations of syphilis. Many practitioners will be faced with diagnostic and treatment decisions while the infants are still in the newborn nursery. Occasionally, a child will escape diagnosis and present with symptomatic syphilis later. This disease should not be overlooked in the differential diagnoses of many seemingly simple childhood complaints.

Acute abdominal pain in the presence of hemi-corporeal neurosensory deficits.

Acute abdominal conditions may be extremely difficult to diagnose in patients with spinal cord neurologic deficits. Syringomyelia, and the surgical treatment of it, can cause an unusual distribution of neurosensory defects involving primarily pain and temperature sensation, and this can mask occult intraabdominal pathology. We report a case of acute abdominal pain in a patient previously treated with a syringo-pleural shunt for correction of a cervical syringomyelia and the difficulties in diagnosis that this presents.

Prolonged sedation associated with secobarbital in newborn infants receiving ventilatory support.

Newborn infants receiving ventilatory support often require sedation. Secobarbital is commonly used in these patients, but dosage guidelines to avoid prolonged sedation are not available. Seventeen infants (gestational age, 30 to 40 weeks; postnatal age, 0 to 3 days) with hyaline membrane disease or persistent pulmonary hypertension on mechanical ventilation were studied. These patients received secobarbital, 4 to 14 mg/kg/day intravenously for 1 to 10 days to produce sedation. Sedation was considered prolonged if it lasted more than 24 hours after the last dose. Nine of 17 infants experienced prolonged sedation. The mean daily secobarbital dose was 11.2 mg/kg/day in patients with prolonged sedation and 6.9 mg/kg/day in those patients without (p less than 0.05); the cumulative mean dose in the respective groups was 33.3 and 21.3 mg/kg (p less than 0.05). Four infants were sedated for 3 to 4 days after stopping secobarbital; the mean daily and cumulative dose was 13 mg/kg/day and 53 mg/kg in these patients. Duration of sedation was related to both daily and cumulative doses of secobarbital. Based on our results, the daily dose of secobarbital should not exceed 7 mg/kg/day to avoid prolonged sedation in infants. Frequent monitoring appears necessary to ensure efficacy with the lowest cumulative dose of secobarbital in newborn infants.

Combination chemotherapy with adramycin (NSC-123127) and dimethyl triazeno imidazole carboxamide (DTIC) (NSC-45388) in children with metastatic solid tumors.

Combination chemotherapy with adriamycin and DTIC was used in 102 evaluable patients under 15 years of age who had previously treated metastatic solid tumors. Responses, defined as 50% or more reduction in all tumor masses, occurred in 10 out of 27 patients with neuroblastoma, 3 out of 8 patients with Wilms tumor, 7 out 15 patients with Ewing sarcoma, 2 out of 6 patients with osteosarcoma, 5 out of 13 patients with rhabdomyosarcoma, and 15 out of 33 patients with miscellaneous tumors which included a patient who had a complete regression of an extensive juvenile angiofibroma. Response rate to combination chemotherapy with adriamycin and DTIC in patients with Ewing sarcoma was significantly superior to the response rate obtained with adriamycin alone in another Southwest Oncology Group Study. Major toxicity included nausea, vomiting, myelosuppression, high incidence of pneumocystis carinii pneumonia (5 patients) and congestive heart failure (4 patients). There was 7 drug-associated deaths due to sepsis (1), pneumocystis carinii pneumonia (4), and congestive heart failure (2).