Biomedical subjects
Publications and source records attributed to R Alexander.
A case of oromandibular-limb hypogenesis syndrome, Type II A, hypoglossia-hypodactylia is reported. The features essential for the diagnosis of this congenital defect include a reduction in tongue size, hypoplastic mandible and variable limb anomalies.
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Ciné film and synchronized records of respiratory flow were obtained from Thoroughbred racehorses cantering on a treadmill at speeds of 9 and 11 m s-1. Horses and some other galloping and hopping mammals link their breathing and locomotion, taking exactly one breath per stride. Three theoretical mechanisms by which the movements of locomotion might drive ventilation are considered. (i) Flexion of the lumbosacral joint and the resulting forward sweep of the pelvis pushes the viscera against the diaphragm. However, back flexion lags behind ventilation at 11 m s-1 and could not exclusively drive ventilation at this speed. (ii) Loading of the thorax by the impact of the forelimbs with the ground might force air out of the lungs. If the respiratory system were damped sufficiently to perform as this mechanism requires, the work of driving ventilation would make up approximately 15% of the total work of running. In comparison with other estimates of the work of ventilation this seems improbably high. (iii) The observed phase relationship between displacements of the viscera, caused by the accelerations of the body during running, and respiratory airflow is not consistent with a tuned visceral piston mechanism driving breathing. Thus, it would seem likely that back flexion is likely to contribute towards driving ventilation but loading of the thorax and the visceral piston mechanism do not.
Twelve patients with biliary colic had no evidence of gallstones but underwent cholecystokinin-augmented hepatobiliary scintigraphy that revealed gallbladder ejection fractions of less than 35%. All 12 patients underwent cholecystectomy. Biliary colic was relieved in all patients at a mean postoperative follow-up of 2.5 years. The biliary colic in these patients was probably caused by abnormal gallbladder emptying, itself apparently produced by either cystic duct obstruction or abnormal motility. Biliary abnormality was seen at operation in most patients, and all patients had abnormalities of the gallbladder or cystic duct seen grossly or histologically. These abnormalities included cystic duct stenosis or adhesions, chronic inflammation, and cholesterolosis.
Serious injury can occur to children who are shaken, especially if the shaking is repeated or part of a pattern of abuse. Serial abuse in connection with children who are shaken and their siblings has important therapeutic and legal ramifications. From an ongoing study of child abuse and head trauma, 12 of 24 victims of shaking that resulted in intracranial injury were identified who had coexisting evidence of direct external trauma. Seventeen children (71%) had evidence of prior abuse, neglect, or both, including 8 who had multiple intracranial hemorrhages. Of the 21 families represented, 9 had more than one child, 3 (3%) of which had several siblings who had been victims of child abuse. Shaking of children usually is not an isolated event, as it frequently has been preceded by other types of abuse.
Shaking as a mechanism of severe brain injury in infants has been challenged on a theoretical basis as insufficient to explain the magnitude of observed injuries. Computed tomography and magnetic resonance imaging, developed since shaken baby syndrome was first described, are helpful in establishing whether external trauma occurred for infants thought to have been shaken. We compiled data from 24 infants initially diagnosed as having shaken baby syndrome, including physical examination, roentgenograms, computed tomography or magnetic resonance imaging, and autopsy (when applicable). Half of the patients showed no evidence of direct impact, and evidence of external trauma was not predictive of a fatal outcome. These findings indicate that shaking by itself is sufficient to cause severe or fatal intracranial injury and that the shaken baby syndrome reflects a spectrum of such child abuse injuries that may include direct trauma or only shaking.
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The validity of self-reports from 171 former patients at a 28-day inpatient treatment program was examined by comparing self-report measures of abstinence and current life functioning with concurrent reports by significant others. Strong convergent validation was found, with 92% of significant others agreeing with the self-reports of the former clients. The "quality of sobriety" measures of familial, occupational, social, and emotional adjustment were studied and validated by the convergent validation technique. Discussed is the value of convergent validation in terms of both follow-up success rates and program evaluation. Methodological concerns and resulting limitations of the data are reviewed.
Five cases of Munchausen syndrome by proxy (MSBP) are presented in which more than one child in the family was victimized. There was a high incidence of maternal psychiatric histories, marital difficulties, and Münchhausen syndrome in the mothers themselves. Seventy-one percent of the children in the families were known to be victims of MSBP; four of these children (31%) died. Multiple-child MSBP may reflect more significant maternal psychopathology than found in other cases of MSBP, or it may indicate the deteriorating consequences to the mother and other children in the family if this syndrome is not identified with the first child and effective interventions made.
Munchausen syndrome by proxy (MSBP) is a form of child abuse in which a parent falsifies illness in a child by fabricating or producing symptoms and presenting the child for medical care while disclaiming knowledge as to the cause of the problem. This report presents the case history of a child diagnosed with MSBP who was portrayed as having multiple developmental disabilities by her mother. Three elements of the case are noteworthy. The emphasis by the mother on multiple developmental disabilities has not been reported. The complexity of this case is unusual and may reflect the complexity of the mother's psychopathology. The interdisciplinary team evaluation was instrumental in making the diagnosis.
Partnership disputes are not uncommon. Settlement in the courts is expensive and may bring unwelcome publicity. Dr Alexander has acted as arbitrator between GPs and commends arbitration as a cheaper, more private, alternative.
IgA nephropathy (IgAN) leads to renal failure in up to 30% of affected children and adults. There is currently no consensus on therapy in IgAN. Six patients with risk factors for disease progression were identified based on clinical or histologic findings. These patients were treated with alternate-day prednisone for 12 to 60 (mean, 36) months and followed for 28 to 60 (mean, 54) months. Follow-up biopsies were available in four patients. At last examination all treated patients had normal urinalysis and serum creatinine level. Follow-up biopsies showed stable or improved glomerular histology in three of four patients. One patient had a slight worsening of the interstitial disease. No steroid toxicity was observed. The outcome of these treated patients was compared with that of 15 comparable patients from another center who received no treatment and with patients from two published clinical pathology series. A normal urinalysis was found at follow-up in all treated patients, compared with one of 15 untreated patients (P = 0.003). None of the patients in the published series with comparable disease had normal urinalysis at follow-up. End-stage renal disease or renal insufficiency occurred in seven of 15 untreated and no treated patients (P = 0.19). The data strongly support the need for a prospective control trial of prednisone therapy in IgAN.
To determine the cellular composition of subretinal membranes in proliferative vitreoretinopathy, surgically excised membranes were studied using electron microscopic and immunohistochemical procedures. Light microscopic immunohistochemistry was found to be superior to conventional electron microscopy as a means of evaluating the relative contributions of retinal pigment epithelium and glia to subretinal membranes. The cells of subretinal membranes chiefly comprised retinal pigment epithelium while glial cells were either absent or contributed only a minor component. It is proposed that the clinical properties of subretinal membranes in proliferative vitreoretinopathy derive from their retinal pigment epithelial cell element.
A DNA probe assay (PACE; Gen-Probe, San Diego, Calif.) was compared with a culture reference method for the detection of Chlamydia trachomatis. Using stock isolates of each of the 15 serovars (A to K, Ba, L1, L2, and L3) of C. trachomatis, the lower limit of sensitivity for the DNA probe ranged between 1,086 inclusion-forming units (IFU) for serovar E (Bour) to 2,930 IFU for serovar L1 (440), with the only exception being serovar C (TW-3), with which 99 IFU was detected. There was no cross-reactivity with Chlamydia psittaci (Texas turkey) and Chlamydia pneumoniae (TWAR-183). Bacterial and fungal isolates representing 14 species of normal vaginal flora as well as Neisseria gonorrhoeae gave negative results with the DNA probe when tested at a level of 1.5 X 10(7) CFU/ml. In addition, the DNA probe, a direct fluorescent-antibody stain (DFA) (MicroTrak; Syva Corp., Palo Alto, Calif.), and an enzyme-linked immunosorbent assay (Chlamydiazyme; Abbott Laboratories, North Chicago, Ill.) were compared with culture for the detection of C. trachomatis, using 196 clinical cervical samples. Of the 196 samples, 20 (10%) were culture positive. Of the 176 culture-negative samples, 1 was not evaluated by DNA probe and 4, because of a lack of cellular material, were not evaluated by DFA. The sensitivities of the DNA probe, DFA, and enzyme-linked immunosorbent assay were 60, 75, and 85%, respectively, and specificities were 95, 99, and 97%, respectively. Of the false-positive direct results, there was only one specimen with which more than one direct method was positive, and with this specimen all three direct methods were positive. The majority of false-negative results by the direct methods were from specimens which by the culture method gave <100 IFU per culture.
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Horseradish peroxidase was used to describe the positions and approximate numbers of neurones with axons that descend to the lumbar spinal cord in normal axolotls and axolotls whose spinal cord had been transected 3-23 months previously. Three to 4 months after the transection approximately 10% of the axons had grown across the cut and returned to the lumbar spinal cord whereas 23 months after the transection the number and distribution of these cells were approaching those of the controls.
Human immunodeficiency virus (HIV 1) strains were isolated from peripheral blood lymphocytes of eight homosexual men (two asymptomatic and six with lymphadenopathy syndrome) and of the wife of an AIDS patient with AIDS-related complex. All except one had antibodies to HIV in their serum. Virus isolation was carried out by cocultivation of the donors' peripheral lymphocytes with HUT-78 cells or with phytohemagglutinin-stimulated normal cord blood lymphocytes. Identification of the virus was based on detection of specific cytopathogenic effects, determination of reverse transcriptase activity, specific immunofluorescence and Southern blot analysis of HIV proviral DNA in the infected cell cultures.