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Biomedical subjects

R Cantor

Publications and source records attributed to R Cantor.

At least 19 recordsLinked to original sources
PubMed2004

A locus for spondylocarpotarsal synostosis syndrome at chromosome 3p14.

Spondylocarpotarsal synostosis syndrome is a rare autosomal recessive disorder characterised by vertebral fusions, frequently manifesting as an unsegmented vertebral bar, as well as fusions of the carpal and tarsal bones. In a study of three consanguineous families and one non-consanguineous family, linkage analysis was used to establish the chromosomal location of the disease gene. Linkage analysis localised the disease gene to chromosome 3p14. A maximum lod score of 6.49 (q = 0) was obtained for the marker at locus D3S3532 on chromosome 3p. Recombination mapping narrowed the linked region to the 5.7 cM genetic interval between the markers at loci D3S3724 and D3S1300. A common region of homozygosity was found between the markers at loci D3S3724 and D3S1300, defining a physical interval of approximately 4 million base pairs likely to contain the disease gene. Identification of the gene responsible for this disorder will provide insight into the genes that play a role in the formation of the vertebral column and joints.

Carpal Bones↗
PubMed1998

Genetic mapping and haplotype analysis of oculopharyngeal muscular dystrophy.

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant muscular dystrophy characterized by late onset ptosis, proximal muscle weakness and swallowing difficulties. This disease has been recently linked to chromosome 14q11.2-q13 in French-Canadian pedigrees. We studied three unrelated American families with OPMD of Hispanic descent and our results indicate that in this ethnic group, this disease also maps to chromosome 14q11.2-q13 (marker MYH7.24; Zmax = 3.98; theta max = 0). These results represent an independent demonstration of disease linkage in a second distinct ethnic group. Furthermore, our analysis demonstrates a unique haplotype that is shared by affected individuals from all three families suggesting a founder effect for OPMD in this population. Meiotic recombinants and radiation hybrid mapping permit the narrowing of the critical region to 1 Mb which will facilitate positional cloning of the OPMD disease gene.

Chromosome Mapping↗
PubMed1998

Localization of a multiple synostoses-syndrome disease gene to chromosome 17q21-22.

Multiple synostoses syndrome is an autosomal dominant disorder characterized by premature onset of joint fusions, which initially affect the interphalangeal joints, by characteristic facies, and by deafness. We performed linkage analysis on a large Hawaiian family with multiple synostoses syndrome. Because another autosomal dominant disorder, proximal symphalangism, shares some clinical symptoms with multiple synostoses syndrome and has been linked to markers at loci at chromosome 17q21-22, we tested the hypothesis that multiple synostoses syndrome is linked to the same chromosomal region. Using polymorphic markers from the proximal symphalangism interval, we conducted linkage analysis and showed that the multiple synostoses-syndrome phenotype is linked to the same chromosomal region. A maximum LOD score of 3.98 at recombination fraction of .00 was achieved for the marker at locus D17S787. Further genetic analysis identified individuals with recombinant genotypes, allowing localization of the disease gene within the interval D17S931-D17S792, a 16-cM region. These data provide evidence that multiple synostoses syndrome and proximal symphalangism may be allelic disorders.

Abnormalities, Multiple↗
PubMed1998

Frequency of post-poisoning exposure information provided to patients requiring emergency care.

Pediatric unintentional poisoning is common despite preventative efforts. Children who have had a poison exposure are at increased risk for subsequent exposure. The purpose of our trial was to determine how often poison prevention information is provided to child care providers in health care facilities (HCF). This was a prospective telephone survey of 100 cases of unintentional poisonings of children ages 1-5 y referred to a HCF. Excluded were cases of patients that had intentional or chronic exposures. Eighty cases received no prevention material; 20 cases received Poison Prevention Information. Ninety-three of the patients were discharged from the emergency department, 6 patients were discharged from a pediatric floor, and 1 was discharged from a Pediatric ICU. Follow up calls to home may be difficult after the patient is referred to a HCF and many families did not receive poison prevention materials. This study indicates the need for a poison prevention discharge packet to be distributed to provide uniform and complete poison prevention education.

Child, Preschool↗
PubMed1997

Temporal bone analysis of patients with presbycusis reveals high frequency of mitochondrial mutations.

Presbycusis is a histologically and genetically heterogenous group of disorders, which lead to progressive, primarily sensorineural hearing loss with aging. Acquired mitochondrial DNA defects have been proposed as important determinants of aging, particularly in neuro-muscular tissues. The spiral ganglion and membranous labyrinth from archival temporal bones of 5 patients with presbycusis were examined for mutations within the mitochondrially-encoded cytochrome oxidase II gene. When compared to controls, results indicate that mitochondrial mutations in the peripheral auditory system occur commonly with age-related hearing loss, that there is great individual variability in both quantity and location of mutation accumulation, and that at least a proportion of presbycusis patients have a highly significant load of mutations in auditory tissue. This work supports the hypothesis that acquired mitochondrial mutations are a determinant of hearing loss in a subgroup of presbycusis patients.

Aged↗
PubMed1997

Pemoline induced acute choreoathetosis: case report and review of the literature.

BACKGROUND: Pemoline is an oxazolidine derivative that is structurally different from amphetamines and used in the treatment of attention deficit disorder. Pemoline has not been commonly associated in the literature as a cause of acute movement disorders. The following case describes two children acutely poisoned with pemoline who experienced profound choreoathetosis. CASE REPORT: Two, 3-year-old male, identical twin siblings presented to the emergency department after found playing with a an empty bottle of pemoline originally containing 59 tablets. The children had a medical history significant for attention deficit disorder previously treated with methylphenidate without success. This was their first day of pemoline therapy. The choreoathetoid movements began 45 min to 1 h after ingestion. The children gave no history of prior movement disorders and there was no family history of movement disorders. The children received gastrointestinal decontamination and high doses of intravenous benzodiazepines in an attempt to control the choreoathetoid movements. Despite treatment, the children continued to have choreoathetosis for approximately 24 hours. Forty-eight hours after admission, the children appeared to be at their baseline and were discharged home. CONCLUSION: Pemoline associated movement disorder has been rarely reported in the acute toxicology literature. The possibility of choreoathetoid movements should be considered in patients presenting after pemoline overdose.

Athetosis↗
PubMed1995

Combined intraoperative radiation and perioperative chemotherapy for unresectable cancers of the pancreas.

PURPOSE: To evaluate the effectiveness of combined intraoperative radiation therapy (IORT) and perioperative chemotherapy in the management of unresectable pancreatic cancer. MATERIALS AND METHODS: Forty-nine patients with localized unresectable adenocarcinoma of the pancreas were treated in a multimodality program of initial IORT and perioperative chemotherapy (fluorouracil [5-FU]/leucovorin) followed by combined external-beam radiation (40 to 55 Gy) and continued chemotherapy. Patients were evaluated for toxicity, pattern of failure, and survival. The follow-up times of these patients range from a minimum of 12 months to a maximum of 62 months, with a median of 28 months. RESULTS: The incidence of perioperative mortality was 0%. Early postsurgical morbidity (grade 3/4) was observed in seven of 49 patients (14%) and late treatment-related morbidity (grade 3/4) in eight of 43 patients (19%) alive beyond 6 months. Morbidity was primarily gastrointestinal (GI), with no hematologic toxicities observed. The median survival time in the total group of patients is 16 months, with a 2-year survival rate of 22% and a 4-year survival rate of 7%. Freedom from local progression of disease was achieved in 71% of patients. CONCLUSION: The patients who undergo IORT with electrons and treated with perioperative chemotherapy (5-FU leucovorin) followed by additional external-beam radiation and chemotherapy appear to have improved survival, with few early or late complications. Dose escalation of external-beam radiation and chemotherapy may further improve local control of disease and survival of patients.

Actuarial Analysis↗
PubMed1994

Pediatric analgesia and sedation.

Sedation and analgesia are essential components of the ED management of pediatric patients. Used appropriately, there are a number of medications and techniques that can be used safely in the emergency care of infants and children. Emergency physicians should be competent in the use of multiple sedatives and analgesics. Adequate equipment and monitoring, staff training, discharge instructions and continuous quality management should be an integral part of the ED use of these agents.

Analgesia↗
PubMed1994

Carcinoma of the pancreas--the Jefferson experience 1975-1988.

A retrospective review of 410 patients with carcinoma of the pancreas seen at Thomas Jefferson University from 1975-1988 was undertaken to provide a global view of the effectiveness of different modalities of treatment in the management of this disease. There were seven patients with Stage I disease, 141 patients with Stage II disease, 91 with Stage III, and 171 with Stage IV disease. The overall median survival was 7 months and a 1-year survival of 30% was observed. Median survival was 15 months for Stage I, 10 months for Stage II, 9 months for Stage III and 4 months for Stage IV patients. Several treatment approaches were utilized in these patients. Twenty-three patients underwent surgical resection. Five of these had Stage I tumor, and 18 patients had Stage II or III disease. Median survival in this group was 12 months with an operative mortality of 13%. No resected patients survived greater than 3 years. Eleven patients with Stage II and III disease received chemotherapy alone, 28 patients received external radiation alone, and 30 patients received Iodine-125 implantation plus external radiation. Median survival in all three groups was 7 months. Forty-five patients received combined chemotherapy plus external radiation for Stage II and III cancer with a median survival of 10 months and a 2-year survival of 14%. Eighty-one patients received combined Iodine-125 implantation+external radiation+chemotherapy and had a median survival of 13 months and a 2-year survival of 22%. Local control of disease was achieved in 74% of these patients. This combined modality approach appears to have the best potential for control of primary cancer and long-term survival of selected patients.

Adenocarcinoma↗
PubMed1992

Long-term results of combined modality treatment with I-125 implantation for carcinoma of the pancreas.

From 1981 to 1987, 81 patients with localized, unresectable carcinoma of the pancreas were treated at Thomas Jefferson University Hospital with a combination of intraoperative Iodine-125 implantation, external beam radiation, and peri-operative systemic chemotherapy. Fifty patients had Stage II disease and 31 patients had Stage III disease. Radioactive Iodine-125 seeds were implanted intraoperatively into the tumor to deliver a minimum peripheral dose of 12,000 cGy over one year. This was followed by external beam radiation (50-55 Gy) and systemic chemotherapy (5-FU, Mitomycin-C +/- CCNU). Incidence of peri-operative mortality was 5% (4/81). Early morbidity was observed in 34% of patients and late complications in 32%. A median survival of 12 months and 2- and 5-year survival rates of 21% and 7% were observed. The determinate 2- and 5-year survival rates were 28% and 13%, respectively. The overall 2- and 5-year survival rates with Stage II disease were 27% and 8% and for Stage III disease, 13% and 3%, respectively (p less than 0.05). The determinate 2- and 5-year survival rates were 34% and 19% for Stage II and 19% and 5% for Stage III disease, respectively (p = 0.08). Local control of disease was achieved in 71% of patients. This combined modality approach appears to have achieved satisfactory local control of primary cancer and long term survival of selected patients.

Adenocarcinoma↗
PubMed1991

A 37-channel DC SQUID magnetometer system.

A 37-channel DC SQUID magnetometer system has been built for biomagnetic studies. The SQUID loop of each magnetometer serves as the active sensing element, thereby eliminating the need for flux coupling circuits. The magnetometers are located approximately 3 cm above the outer dewar bottom. The SQUIDs are directly coupled to highly simplified read-out electronics using only five wires per channel; no helium temperature impedance matching circuits are required. Each channel can be independently inserted into or removed from the dewar. Using a novel electronic noise reduction technique the system white and 1 Hz flux density noise values are typically 5 and 10 fT Hz-1/2, respectively, including the noise contribution of the in-house fabricated dewar and the magnetically shielded room. The two parts of the data-processing system allow independent handling of the acquisition and analysing task. Two example measurements demonstrate the advantage of the electronic noise reduction method.

Equipment Design↗
PubMed1991

The use of aspirin to prevent heterotopic ossification after total hip arthroplasty. A preliminary report.

The reported incidence of heterotopic ossification (HO) after total hip arthroplasty (THA) ranges up to 50%. HO causes pain and restricted range of motion (ROM) in a significant number of these THA patients. From 1983 to 1988, 177 primary cemented THAs were performed in 131 consecutive patients. Six hundred fifty milligrams of buffered aspirin administered twice daily for two weeks was used as a prophylaxis for thromboembolic disease. There was an unusually low incidence of HO in this group of patients. Aspirin treatment was instituted the night before surgery and continued for two weeks, except in 13 patients (7%) who had to stop treatment because of gastrointestinal symptoms. All patients had at least one year of roentgenographic study postoperatively. According to the Brooker Classification of HO, there were 169 (96%) Grade I and Grade 0 hips, six (3%) Grade II, two (1%) Grade III, and no Grade IV. None of the patients had symptomatic restriction of ROM attributable to heterotopic bone. Aspirin is a safe and inexpensive agent for prevention of HO after THA.

Aspirin↗
PubMed1990

Mapping of a gene determining tuberous sclerosis to human chromosome 11q14-11q23.

Tuberous sclerosis (TSC) is a dominantly inherited disorder characterized by hamartomas and hamartias in one or more organs, most often in skin, brain, and kidneys. Analysis of the basic genetic defect in tuberous sclerosis would be greatly expedited by definitive determination of the chromosomal location of the TSC gene or genes. We have carried out genetic linkage studies in 15 TSC families, using 34 polymorphic markers including protein markers and DNA markers. Pairwise lod scores were calculated using LIPED, and multipoint analyses were carried out using MENDEL. In the pairwise linkage analysis, using a penetrance value of 90%, a significant positive lod score was obtained with MCT128.1 (D11S144), 11q22-11q23, Zmax 3.26 at theta = 0.08. The tyrosinase probe TYR (11q14-11q22) gave a maximum lod score of 2.88 at theta = 0. In the multipoint analyses the most likely order is (TYR,TSC)-MCT128.1-HHH172. Homogeneity analysis was carried out using the USERM9 subprogram of MENDEL, which conducts the admixture test of C. Smith (1963, Ann. Hum. Genet. 27: 175-182). This test provided no evidence for genetic heterogeneity (that is, non-11-linked families) in this data set.

Alleles↗
PubMed1986

Echocardiographic abnormalities and disease severity in Fabry's disease.

Fabry's disease is an X-linked recessive genetic deficiency of the enzyme alpha-galactosidase A, which leads to the pathologic deposition of neutral glycosphingolipids in lysosomes of the vascular endothelium of the heart, brain and kidney. The disease is progressive in hemizygous male patients, with increasing involvement of the major organs leading to death. Because cardiac involvement is a constant feature, echocardiograms were performed on 35 patients with Fabry's disease, 23 hemizygotes (aged 28.6 +/- 14 years) and 12 heterozygotes (aged 31.6 +/- 6 years), to determine whether cardiac involvement could be detected noninvasively. The results demonstrated that hemizygous male patients had a greater aortic root diameter, thicker interventricular septum and greater ventricular mass than did heterozygous female patients. Left ventricular mass per square meter of body surface area correlated well with clinical disease severity (r = 0.68, p less than 0.05), suggesting progressive glycosphingolipid deposition. Older heterozygotes (greater than 25 years old) had more severe evidence of cardiac disease than did younger male patients. Although mitral valve prolapse was identified in 12 (54%) of 23 male hemizygotes and in 7 (58%) of 12 female heterozygotes its presence did not correlate with clinical disease severity or other echocardiographic variables. Therefore, echocardiographic evidence of Fabry's disease appears to correlate with age-related disease severity and may be a useful noninvasive marker to follow disease progression and possible regression when appropriate therapy becomes available.

Adult↗