Aromaticity and photophysics of tetrasila- and tetragerma-annelated tetrathienylenes as new representatives of the hetero[8]circulene family.

The electronic structure, absorption and emission spectra, aromaticity and photophysical behavior of the recently synthesized tetrasilatetrathia[8]circulene and tetragermatetrathia[8]circulene compounds have been studied computationally. Both compounds demonstrate a specific bifacial aromaticity, which is unusual for hetero[8]circulenes; the inner eight-membered core sustains an expected strong paratropic magnetically-induced ring current, while the outer perimeter contains saturated Si(Et)2 and Ge(Et)2 moieties which break the conjugation between the thiophene rings. The overall magnetically-induced ring current for both studied circulenes is close to zero because of the strong local diatropic currents in each thiophene ring that compensate the paratropic counterpart. The electronic absorption and emission spectra of tetrasilatetrathia[8]circulene and tetragermatetrathia[8]circulene demonstrate a clear visible vibronic progression. The 0-0 band is the most active one in the absorption spectra, while in the fluorescence spectra the 0-1 band composed of several normal vibrations is more intense compared with the 0-0 band in excellent agreement with experiment. Accounting for spin-orbit coupling effects, an analysis of the photophysical constants for the two compounds demonstrates: (1) a clear manifestation of the internal heavy atom effect on the inter-system crossing efficiency; (2) one to two order domination of non-radiative rates over the fluorescence rate; and (3) that the S1-S0 internal conversion is extremely slow and can not compete with the fluorescence, while the S1-Tn inter-system crossing is a main deactivation channel of the S1 excited state. These results provide new insight into the electronic structure and photophysics of tetrasilatetrathia[8]circulene and tetragermatetrathia[8]circulene as novel standalone representatives of hetero[8]circulenes - tetraannelated derivatives of tetrathienylene.

Pulmonary hypertension and HIV infection: new observations and review of the syndrome.

This report describes the case of a 14-yr-old hemophiliac who died of complications of primary pulmonary hypertension. He was infected with the human immunodeficiency virus. The autopsy disclosed that he also had membranoproliferative glomerulonephritis type III and hepatic cirrhosis, both clinically unsuspected. This is the second report describing the association of membranoproliferative glomerulonephritis type III and primary pulmonary hypertension in an HIV-infected patient and the first to consider cirrhosis as a possible additional element of the syndrome.

Osteolysis of the calcaneus in a child with localized scleroderma.

In a young girl with localized scleroderma a circumscribed area of lysis developed in the calcaneus beneath the involved skin and soft tissues of the foot. A biopsy revealed vascular changes characteristic of scleroderma associated with infarction and severe resorption of the bone. A geographic pattern of bone destruction in a child with localized scleroderma has not previously been reported.

Cerebral rhinocele, hydrocephalus, and cleft lip and palate in infants with cardiac fibroma.

Cardiac transplantation was performed in two infants with unresectable fibromas of the myocardium. In one patient, lip surgery was also required for unilateral cleft lip and palate. At autopsy, communicating hydrocephalus of mild to moderate degree was found in both cases. In the patient with facial clefts, there was also a large, ipsilateral cyst, or rhinocele, of the olfactory lobe. This unusual lesion, which seems to represent a previously unreported malformation, was apparently formed by segmental dilatation of a persistent olfactory ventricle. Cerebral or cranial anomalies are thought to be rare in cases of cardiac fibroma; however, macrocephaly was present in five patients. Furthermore, presenting abnormalities among previously reported cases included hydrocephalus in one case, and cleft lip and palate in another. These and other findings suggest that, at least in some cases, cardiac fibroma is a manifestation of a more extensive developmental disorder.

Translocation 10;17 in clear cell sarcoma of the kidney. A first report.

This is the first report of a t(10;17) as the unique cytogenetic finding in one case of a rare childhood tumor, clear cell sarcoma of the kidney (CCSK). This observation is discussed in relation to the cytogenetics of Wilms' tumors, of which CCSK is a variant.

De novo circumscribed pulmonary lobar cystic lymphatic anomaly in a young boy. A possible sequela of bronchopulmonary dysplasia.

This report describes a massive pulmonary lymphatic cystic anomaly affecting the right lower lobe of a nine-year-old boy. A year earlier, only an ill-defined small infiltrate could be seen in the affected lobe radiologically. The pathogenesis of this highly unusual lesion is discussed, taking into consideration the possible role of three months of mechanical ventilation in the neonatal period.

Lipid aspiration pneumonia due to gastroesophageal reflux. A complication of nasogastric lipid feedings.

The development of lipid aspiration pneumonia after chronic nasopharyngeal installation of mineral oil was first described in 1925 by Laughlin. Since that time this entity has been well recognized and numerous substances have been identified or implicated as the aspirated material. The classic radiographic appearance of severe chronic lipid aspiration pneumonia has been described as consisting of intense perihilar infiltrates. However, the radiographic findings are more often non-specific and usually consist of varying degrees of diffuse interstitial infiltrates that tend to be more prominent in the perihilar regions and the right lung. We are reporting a case of biopsy-proven lipid aspiration pneumonia in an infant with known gastro-esophageal reflux (GER) who had medium-chain triglyceride oil administered via nasogastric tube. Serial roentgenograms demonstrated a changing pulmonary pattern from diffuse bilateral interstitial infiltrates initially to a diffuse alveolar pattern at the time of the lung biopsy. Modern medicine has developed new methods for providing nourishment to sick newborns and infants to improve their nutritional status and help them to grow. One such method involves the administration of medium-chain triglycerides (MCT oil) into the GI tract via a nasogastric or nasoenteral tube. The purpose of this report is to describe a significant complication of this method of providing nutrition to an infant with gastroesophageal reflux (GER) and the diagnostic dilemma it presented.