Monozygotic twinning and structural defects.

An excess of structural defects occurs in monozygotic twins compared in dizygotic twins or singletons. The excess is composed of three categories of defects. The first includes defects which are part of the MZ twinning, such as conjoined twins and some amorphous twins. In addition, all early embryonic malformations and malformation complexes such as sirenomelia mc. holoprosencephaly mc. and anencephaly mc are increased in MZ twins. The reason for this association is considered to be the common etiology for both the MZ twinning and the early malformation problem. MZ twins provide an excellent model for appreciating the spectra of particular malformation complexes, since the twins often have different gradations in severity of the same type of structural defect. The finding of both discordant and concordant MZ twins with Goldenhar, de Lange, and Rubinstein-Taybi syndromes suggests that these "syndromes" might be early malformation complexes. The other two categories are considered secondary to the MZ twinning process. The most unique category results from any vascular interchange between the MZ twins. Depending on their nature, vascular connections may give rise to reverse flow with acardiac status in one twin during early development, or to vascular disruptions from a deceased co-twin with intravascular coagulation causing embolization in the surviving co-twin. The latter defects may include microcephaly, porencephalic cysts, hydranencephaly, intestinal atresia, aplasia cutis, and limb amputation. Unequal growth may occur as a result of artery to vein placental anastomoses. The final category is deformations due to crowding in utero during late gestation. These do not differ from those in DZ twins.     

Polypoid sarcomas of the esophagus. A rare but potentially curable neoplasm.

Five patients with polypoid esophageal sarcoma are reported. All had dysphagia similar to that occurring in epithelial carcinoma of the esophagus. The clinical diagnosis of sarcoma was suspected when barium swallow showed a large polypoid lesion. Biopsy was often inconclusive concerning the nature of the lesion except to identify it as a neoplastic process. In spite of their large size, the tumors remained superficial within the esophageal wall. Nodal or distant organ metastasis was absent in 4 of the 5 patients. The histology of these tumors suggests that so-called carcinosarcoma is an epithelial carcinoma of the esophagus with varying amounts of spindle cell features and should be considered separately from sarcoma arising from mesenchymal tissue. Unlike carcinoma, esophageal sarcoma has a favorable prognosis following radical resection, and recent advances in esophageal surgery have decreased the mortality and morbidity of esophagectomy.     

Parental overprotection and asthma

Using a reliable and valid measure of parental overprotection, the oft-put clinical view that asthmatics' parents are overprotective was confirmed, with asthmatics scoring both their motors and their fathers as similarly overprotective in a controlled study. The study was designed to determine if parental overprotection is likely to be an antecedent to, or a consequence of asthma in a child. Results suggested that parental overprotection is a consequence of asthma in a child, but this was more clearly demonstrated for the fathers than for the mothers. The authors conclude that parental overprotection associated with asthma is likely to reflect an adaptational response by parents to a child with a chronic, unpredictable illness arousing high levels of anxiety in parents.     

Prosthetic cardiac pacers in community hospitals: a physician's experience

This report deals with 53 patients treated with prosthetic cardiac pacers solely by one “interested” physician at the community level over a period of 5 years and 2 months.The 5-year mortality rate was 41.5 per cent; (15.1 per cent cardiogenic and 26.4 per cent noncardiogenic). A complication rate of 28.2 per cent with one fatality (1.9 per cent) due to a faulty pacemaker was experienced. These results compare favorably with a similar medically treated group, who had an immediate in-hospital cardiogenic mortality of 35 per cent. Contrary to other reports, premature battery depletion was not found in this series.This community study compares favorably to several university studies, who report a complication rate of 63 per cent, a mortality rate of 6.7 per cent versus 28.2 and 1.9 per cent, respectively, as experienced in this group. This study indicates that community standards are equal to or superior to university standards in this particular mode of therapy.     

Coxsackie virus myopericarditis. A microbiological and clinical review

Coxsackie viruses belong to a large group of viruses called picornaviruses. This group of viruses contains a ribonucleic acid (RNA) core; the nucleocapsid has cubic symmetry; the virion has no envelope; and infectivity is resistant to lipid solvents such as ether and chloroform. Coxsackie viruses are divided into two groups based on their pathogenicity in suckling mice; group A contains 24 types and group B 6 types. Numerous reports of Coxsackie virus B outbreaks involving adults have established the considerable importance of these viruses as a cause of acute pericarditis and myocarditis. The diagnosis is based on viral isolation and serologic techniques. Coxsackie virus heart disease usually is observed during epidemics Involving several diseases including Bornholm disease or cardlorespiratory tract syndromes. The treatment of acute myopericarditis is mainly supportive.