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Biomedical subjects

D M Klein

Publications and source records attributed to D M Klein.

At least 37 records · Page 2Linked to original sources
PubMed1996

Occipital plagiocephaly: deformation or lambdoid synostosis? I. Morphometric analysis and results of unilateral lambdoid craniectomy.

Between 1987 and 1992, 30 infants aged 1.4-13 months (mean 7.3 months) underwent unilateral lambdoid strip craniectomy at the Children's Hospital of Buffalo for occipital plagiocephaly. Males outnumbered females (22:8) and right-sided occipital flattening was significantly more common than left-sided flattening (25:5). The deformity was noticed at an average age of 3.2 months; 16% of the infants had an asymmetry at birth. Positional preferences (a distinct tendency to lie preferentially on the back, in most cases with the head turned to the ipsilateral side) were described in 79% of infants for whom this information was available, and torticollis was present in 10%. Pre- and post-operative CT scans were analyzed using several morphometric measurements. Asymmetries were measured between the flattened and contralateral sides, both posteriorly and anteriorly, using a translucent grid placed over the CT slice showing maximum asymmetry. The average maximum asymmetry between the flattened and contralateral sides was 24% posteriorly and 16% anteriorly. Significant improvements were seen postoperatively, with both anterior and posterior asymmetries improving by an average of one third (p < 0.05). However, when compared with CT scans from a control group of infants without synostosis, the operated group showed persistent and significant asymmetries postoperatively. The morphometric measurements described allow an objective and reproducible means of assessing the results of various treatments for this disorder. The improvements following unilateral lambdoid craniectomy are difficult to interpret in isolation; we suggest that future efforts be directed toward similarly assessing the results of both nonoperative treatments such as positional changes and molding helmets, and more aggressive surgical treatments that have been advocated for this disorder.

Craniofacial Abnormalities↗
PubMed1996

Occipital plagiocephaly: deformation or lambdoid synostosis? II. A unifying theory regarding pathogenesis.

Occipital plagiocephaly is characterized by both unilateral occipital flattening and ipsilateral frontal prominence with anterior deviation of the ipsilateral ear, yielding a characteristic parallelogram shape to the cranium. Radiographic changes in the lambdoid suture are often evident, but the lambdoid suture is usually patent over most or all of its length on skull X-rays and/or CT scans. Both lambdoid synostosis and deformational forces have been implicated as potentially causal in the pathogenesis of this deformity. We proposed a unifying theory which incorporates a common pathogenesis for both deformational plagiocephaly and most cases of lambdoid 'synostosis'. According to this hypothesis, intrauterine and/or postnatal deformation forces are responsible for the primary calvarial deformation. These forces initially act in reversible manner to produce the typical parallelogram-shaped skull deformity. However, with continued deformation, more enduring secondary pathological changes may eventually occur in the lambdoid suture and basicranium which are more difficult to correct even if the offending deformational forces are subsequently removed or reversed.

Craniofacial Abnormalities↗
PubMed1994

Radiology in survivors of traumatic atlanto-occipital dislocation.

Traumatic atlanto-occipital dislocation is fatal, but survivals are reported. Six cases of survival after atlanto-occipital dislocation are presented. Lateral cervical spine radiographs demonstrated retropharyngeal swelling in all patients, and Powers' ratio was abnormal in five of six patients. Reformatted computed tomography (CT) images or three-dimensional CT were useful in confirming the diagnosis. Initial treatment consisted of immobilization with halo or collar, and, in one patient, Crutchfield tongs. Reduction of the dislocation was associated with decreasing Powers' ratio in five long-term survivors. Residual neurologic deficits, however, were seen in these patients. Atlanto-occipital dislocation should be suspected in trauma patients with findings of brain stem injury--especially agonal respirations, irregular heart rate, lower cranial nerve abnormality, and asymmetrical motor deficits.

Accidents, Traffic↗
PubMed1986

Scheuermann's dorsal kyphosis and spinal cord compression: case report.

Although Scheuermann's disease (juvenile dorsal kyphosis) is a common problem of late childhood and adolescence, its potential for neurological complications is not widely appreciated. In rare instances, spinal cord compression appears to be produced by the kyphotic protrusion alone, and we present an example of this unusual problem. Although the results of surgical treatment in this situation cannot be substantiated, anterior spondylotomy and decompression followed by posterior fixation appear to offer the best mechanical relief. Spinal cord compression can also be produced by extradural cysts, with which Scheuermann's disease is frequently associated. Scheuermann's disease also is reported to occur in combination with thoracic disc protrusion, but the coincidence here may be random. Pertinent literature is reviewed.

Adolescent↗
PubMed1985

Staging of cerebral hemispheric tumors.

There is currently no adequate staging system for cerebral astrocytomas. A scheme for acquiring data that can be used to stage cerebral hemisphere tumors is suggested. This data base, in conjunction with treatment and survival information, may be useful in the management of childhood hemispheric tumors.

Brain Neoplasms↗
PubMed1985

Surgical staging of cerebellar astrocytomas in childhood.

Benign cerebellar astrocytomas of childhood, when removed grossly in toto, have high cure rates and thus can be staged by their surgical resectability. Currently, total tumor resection is limited by attachment to or invasion of the tumor into the brain stem or by evidence of recurrence or metastases. Tumors of the cyst-nodule form are more often amenable to total gross removal because of their discrete margins and lateral placement, which is clear of brain stem structures. However, solid astrocytomas of the cerebellum, with or without visible cysts, may also be surgically cured if there is sufficient clearance from the brain stem. Patients with malignant astrocytomas of the cerebellum or metastases have much poorer prognoses. Preoperative and postoperative staging systems have been suggested based on these assumptions.

Astrocytoma↗
PubMed1985

Skeletal muscle insulin unresponsiveness during chronic hyperdynamic sepsis in the dog.

Recent reports from our laboratory and others have documented changes in insulin unresponsiveness and electrolyte and hormonal changes characteristic of hypodynamic shock states in anesthetized animals. Since most acute shock protocols do not adequately mimic the clinical profile of sepsis, the present study was undertaken to document the hemodynamic and metabolic changes associated with chronic hyperdynamic peritonitis in dogs. Mongrel dogs of either sex weighing 20 +/- 2 kg were surgically instrumented with an electromagnetic aortic flow probe for monitoring cardiac output determinations, and aortic and central venous catheters for withdrawing blood for blood pressure and chemical analyses. Following a recovery period (7-10 days) control hemodynamic and metabolic measurements were made. Sepsis was induced (peritoneal abscess) by implanting a 4" X 4" gauze sponge, previously inoculated with human fecal bacteria, amid the intestines. Experimental (N = 18) and pair-fed control (N = 6) animals were monitored daily for 21 days or until death. During the septic protocol, cardiac index increased from a control value of 3.4 L/min/m2 to 5.5 L/min/m2 by the end of the experimental period. Mean arterial blood pressure, total peripheral resistance index, body weight, and plasma Ca++ fell below control values during the experimental period. Body temperature, plasma glucose, insulin, glucagon, and Mg++ were all elevated with sepsis. At the end of the chronic experimental period, skeletal muscle insulin responsiveness was assessed in the isolated, innervated, constantly perfused gracilis muscle preparation. Pair-fed control animals responded to various concentrations of local insulin infusion by increasing glucose uptake by the gracilis muscle. However, septic animals had a blunted response to local insulin infusion resulting in a decrease in the maximum dose response effect. These data demonstrate that: chronic, hyperdynamic peritonitis in the dog more closely mimics the human clinical profile of sepsis; and hyperdynamic sepsis is associated with a state of skeletal muscle insulin unresponsiveness which results from a post-receptor defect.

Abscess↗
PubMed1985

The understanding heart: aging parents and their favorite children.

This paper compares the characteristics of adult children who provide comfort and sympathy and serve as confidants to parents with those whom parents perceive as disappointing. Interview information from 117 couples having children who had left home was analyzed using aggregate and intrafamilial strategies. The latter analyses compared the characteristics of the selected child with those of her or his sibs instead of comparing the aggregate of selected children with the aggregate of their siblings. Differences in the findings from the 2 techniques are discussed. The findings confirmed the importance of daughters who live nearby as understanding children. More important than proximity among the factors influencing parental judgments on disappointing and understanding children were intergenerational shared interests and values.

Adult↗
PubMed1980

Lung cyclic 3',5'-adenosine monophosphate and adenylate cyclase in endotoxic shock.

Cyclic 3',5'-adenosine monophosphate (cyclic AMP) and adenylate cyclase activity were measured in lungs from guinea pigs in endotoxic shock induced by an intravenous injection of Salmonella enteritidis endotoxin (10 mg/kg body weight). Both cyclic AMP content and adenylate cyclase activity were significantly elevated in lung tissue from the endotoxic guinea pigs. There was no apparent change in the affinity of adenylate cyclase for its substrate (ATP); however, the maximum velocity of the enzyme reaction was increased in lungs from the endotoxic group. Endotoxin, in the concentration range of 10(-4) to 10(-2) micrograms/ml, added to lung homogenates did not affect adenylate cyclase activity. Prostaglandins do not seem to mediate the effects of endotoxin in vivo on lung cyclic AMP since treatment of guinea pigs with indomethacin (10 mg/kg body weight) 30 min prior to endotoxin administration did not alter the endotoxin-induced increase in lung cyclic AMP.

Adenylyl Cyclases↗
PubMed1979

A comparison of computed tomography and air ventriculography in diagnosis of progressive hydrocephalus of infancy.

We have compared the efficacy of computed tomography (CT) and air ventriculography (VGM) in the diagnostic evaluation of progressive nontumoral infant hydrocephalus where both examinations have been done without significant interventing time or treatment in infants under 12 months of age. CT alone was judged to be adequate for diagnosis and treatment 21 of 30 cases reviewed, provided that cerebrospinal fluid studies were available to complete diagnosis where necessary, and provided that the question of ventriculocisternal communication was not a factor in treatment selection. The ability to visualize cerebran aqueduct and 4th ventricle on CT was not always a reliable indicator of ventriculocisternal communication. CT was most adequate as the sole radiographic study in cases of myelodysplasia with Arnold-Chiari malformation, and in premature infants with intraventricular hemorrhage.

Agenesis of Corpus Callosum↗
PubMed1978

Calcification in brainstem gliomas.

Calcification in brainstem gliomas is an unusual histologic and and radiologic finding. To date, radiologic evidence of calcification in these tumors has not been reported. The two patients described here had evidence of calcification on either computerized tomography (CT) or plain skull films. Increasing availability of CT scans may provide a more accurate estimate of the incidence of calcification in these tumors.

Adolescent↗