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Biomedical subjects

M D Goldberg

Publications and source records attributed to M D Goldberg.

At least 19 recordsLinked to original sources

Role of the nucleoid-associated protein Fis in the regulation of virulence properties of enteropathogenic Escherichia coli.

Virulence gene expression in enteropathogenic Escherichia coli (EPEC) is governed by a combination of environmental factors and virulence regulators. These factors control the expression of the bundle-forming pili (BFP), intimin, the type III secretion apparatus and the secreted proteins EspA, EspB, EspD and Tir. Expression of the bfp genes occurs for a short period in early exponential phase during growth in tissue culture medium. The nucleoid-associated regulator protein, Fis, is also expressed transiently during this period. To determine whether Fis was responsible for the growth phase-dependent expression of bfp, fis was deleted from the EPEC strain E2348/69S. Paradoxically, the Delta fis mutant retained the ability to colonize HEp-2 cells in a characteristic localized adherence pattern, and Fis was found negatively to regulate the expression of BFP. However, the Delta fis mutant failed to induce the accretion of filamentous actin, which is associated with attaching and effacing lesions. Using a combination of Western blotting and a novel multiplex primer extension assay (MPEA), we showed that, although the expression of intimin and Tir was not affected, transcription of the LEE4 operon encoding espADB and the virulence activator, Ler, were found to be Fis dependent.

Adhesins, Bacterial↗

Shingles during the course of treatment with 6-mercaptopurine for inflammatory bowel disease.

OBJECTIVE: Our aim was to study the frequency, severity, and outcome of patients with Crohn's disease and ulcerative colitis treated with 6-mercaptopurine (6MP) who developed shingles during treatment, and to recommend management. While varicella can be severe in young people immunocompromised by steroids, the incidence of herpes zoster in older people with inflammatory bowel disease (IBD) and whether its severity is influenced by 6MP and azathioprine are unknown. METHODS: Data were collected from our IBD Center on 550 patients with IBD to identify those who developed shingles while on 6MP, its severity, the dose and duration of 6MP, and the management of the 6MP. RESULTS: Twelve of 550 patients with IBD treated with 6MP developed shingles. In two with herpes zoster ophthalmicus the pain was prolonged, and one patient developed encephalitis which was brief and uncomplicated; in nine patients the course was benign. Acyclovir should be the treatment of choice even though it was available in only three cases. CONCLUSIONS: Shingles occurs more often in IBD patients treated with 6MP than in those who are not, but the course is usually benign and there has been no mortality. The 6MP should be stopped temporarily until severity is established but if the underlying disease warrants further treatment the 6MP should be restarted.

Acyclovir↗

Artefactual cleavage of E coli H-NS by OmpT.

In the bacterium Escherichia coli, H-NS-(H1, H1a) is a heat-stable protein with a molecular mass of 15.5 kDa involved in nucleoid organisation and gene regulation linked to certain signal transduction pathways. We have shown that, following addition of preparations of everted inner membrane vesicles, heat-stable cleavage products of approximately 10 kDa of H-NS are formed in vitro from newly synthesised, radio-labelled H-NS and from purified H-NS. The 15.5 kDa protein and its cleavage products were also recovered from a minicell system. These results raised the possibility that cleavage of H-NS is physiologically significant. However, the cleavage of H-NS observed appears to occur during cell breakage and to depend on the method of protein extraction and the presence of the outer membrane protease, OmpT. Nevertheless, the results indicate that H-NS may contain at least two separate domains with cleavage occurring between these domains at a preferred OmpT site. Failure to take account of H-NS cleavage in sample preparation and analysis can lead to serious underestimation of H-NS levels.

Artifacts↗

Prenatal diagnosis and the pediatric surgeon: the impact of prenatal consultation on perinatal management.

PURPOSE: Pediatric surgeons are increasingly called on by obstetrical colleagues to counsel parents about the implications of a prenatal ultrasound finding. Our understanding of the natural history of many prenatally diagnosed surgical conditions has grown significantly in recent years. Whether prenatal surgical consultation can influence perinatal course had not been investigated. METHODS: During an 21-month period, 12,865 prenatal ultrasound studies were performed on a total of 4,551 patients, and 221 prenatal surgical consultations were obtained through a newly established fetal treatment program at a tertiary care prenatal diagnostic center. To evaluate the impact of prenatal pediatric surgical consultation on perinatal course, the authors reviewed changes in management including termination of pregnancy, in utero intervention, and altered site, mode, or timing of delivery. RESULTS: Two hundred twenty-one fetuses were referred for consultation; their 234 congenital anomalies included genitourinary (36%), thoracic (16%), intraabdominal (14.5%), abdominal wall (10.6%), neurological (9%), skeletal (6%), and head and neck (2.5%) defects; 2.5% had tumors and 2.5% were twin pregnancies. Pregnancy was terminated in 9.5% of cases, because of patient request, chromosomal abnormality, or dismal prognosis. In 3.6%, the decision to terminate was changed as a result of consultation. Site of delivery was changed as a result of consultation in 37% to facilitate postnatal evaluation and initiate immediate treatment. Mode of delivery was changed in 6.8% to prevent dystocia, hemorrhage into a tumor, as in sacrococcygeal teratoma, or to provide an emergency airway, as in cervical teratoma. The timing of delivery was changed in 4.5% to avoid further damage to fetal organs in cases of obstructive uropathy, gastroschisis, sacrococcygeal teratoma with high-output failure, and hydrocephalus. Five percent (11) underwent treatment in utero for fetal hydrothorax, obstructive uropathy, twin-twin transfusion syndrome, or lymphangioma. The overall perinatal mortality rate was 2.5%. CONCLUSION: Prenatal pediatric surgical consultation may have a significant impact on the perinatal management of the fetus with a surgically correctable congenital anomaly. Providing obstetric colleagues and families with valuable insight into the surgical management of anomalies allows fetal intervention when appropriate, and delivery in an appropriate setting, by the safest mode of delivery, and at the gestational age appropriate to minimize effects of the anomaly.

Abortion, Therapeutic↗

In vitro evaluation of iris chafe protection afforded by hydrophilic surface modification of polymethylmethacrylate intraocular lenses.

An in vitro iris chafe test was developed to evaluate possible differences in abrasive interaction of various intraocular lens (IOL) materials with the posterior surface of the iris. The materials that were compared in initial tests with rabbit irides were high molecular weight polymethylmethacrylate (PMMA), the primary IOL material in current use, and surface-modified PMMA, which had a permanent, chemically bound, hydrophilic, polymer surface. Scanning electron microscopy, light microscopy, and examination of histological sections were used to assess tissue damage. A "window defect" type of abrasive damage was observed by light microscopy for PMMA lenses and is very similar in appearance to that seen for iris abrasion by human implants when viewed in vivo in slitlamp examinations. Results for both pigmented and albino rabbit irides indicate a reduction in abrasive insult to the external iris basement membrane and underlying pigment epithelium by the hydrophilic surface modification of PMMA. These results are consistent with our observation of a major reduction in corneal endothelium damage on contact with the hydrophilic surface-modified PMMA as compared with PMMA itself. This in vitro iris abrasion test, therefore, appears to be a useful technique for future evaluation of IOL surface properties.

Animals↗

Appendiceal obstruction by a toothpick removed at colonoscopy.

A case of obstruction of the appendix simulating colon carcinoma is presented. The cause of the patient's symptoms and radiographic findings was found at colonoscopy to be a toothpick embedded in the appendix. The toothpick was extracted colonoscopically. Cases of intestinal obstruction by toothpicks reported in the literature are reviewed.

Aged↗

Genetic microcephaly in a pair of monozygous twins.

A pair of monozygotic female twins with true primary microcephaly is described. The autosomal-recessive nature of the disease is supported by the following: the twins are concordant for the disease; the parents, themselves normal, are related; the reduced skull dimensions were noted at birth; neurologic problems are absent; the karyotype is normal; the gestation and delivery were normal, without any history of influences capable of inducing microcephaly. A detailed dermatoglyphic study is given.

Consanguinity↗

A practicum for oral cancer teaching.

This article describes a hospital-based method for teaching oral cancer to general practice residents, which involves the use of patients for whom the residents are responsible. The residents present prepared cases of patients of the hospital dental department according to a predetermined protocol. These conferences begin with a talk on a subject germane to the cases being presented and include complete documentation of clinical history and laboratory findings, photographs, projection of microscope slides of the lesion, and a thorough discussion of therapy and rehabilitation. The residents have had significant contact with the cancer patients from the time of initial patient complaint to completion of therapy. The practicum is based on thorough case review and builds on didactic information provided in the undergraduate dental school curriculum.

Education, Dental↗

Beau's lines. A case report.

Beau's lines are a depression of the nail surface associated with a severe disturbance which temporarily interferes with the rate of nail growth. They appear several weeks or more after incurrence of the damage and continue to extend during nail growth. These lines were observed soon after birth in all twenty fingernails of an infant girl. The depression extended through the whole thickness of the nails. This would appear to be the first reported case in which Beau's lines have developed so early in life, probably as a result of intrauterine distress.

Female↗

Triplet and quadruplet pregnancies and management.

The rate of multiple pregnancies with more than 2 fetuses has significantly increased since the introduction of ovulation induction agents. From 1970 through 1978, there were 19 triplets and 6 quadruplets in the authors' department, incidences of 1:696 and 1:5370, respectively. Eighteen (72%) of the 25 multiple pregnancies followed treatment with ovulation induction agents and 7 were spontaneous. The diagnosis of more than 2 fetuses was made earlier in the induced than in the uninduced pregnancies. Management, initiated upon diagnosis, included bed rest, high-protein diet, beta-mimetic agents, progestins, dexamethasone late in the second trimester, and selective cerclage. The mean gestational age was 34 weeks in the triplets and 35 weeks in the quadruplets. Forty-four percent of the deliveries were by cesarean section and the remainder were by vaginal delivery. The mean weight of the neonates was 1807 g in the triplets and 1950 g in the quadruplets. The mean overall Apgar score was 8.16, and the perinatal mortality was 185 per 1000, corrected (more than 28 weeks) to 137 per 1000. The main neonatal complications resulted from prematurity, and maternal complications noted were postpartum hemorrhage necessitating hysterectomy in 2 patients. The preferable mode of delivery cannot be stated dogmatically. Fetal outcome was similar in vaginal and cesarean deliveries among the various gestational age groups.

Adult↗

Mesenteric fat necrosis simulating a carcinoma of the cecum.

Fat necrosis in the mesentery is an unusual complication of an adjacent inflammatory process. This report demonstrates a case of fat necrosis resulting in multiple irregularly firm masses measuring up to 4.5 cm. in diameter which produced extrinsic pressure on the cecum and ascending colon, simulating a carcinoma radiographically and at surgery. The fat necrosis was caused by chronic appendicitis in association with pylephlebitis.

Aged↗