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Crystalline and amorphous materials usually possess distinct physicochemical properties due to major variations in long-range and local molecular packings. Enhanced fundamental knowledge of the molecular details of crystalline-to-amorphous interconversions is necessary to correlate the intermolecular structure to material properties and functions. While crystal structures can be readily obtained by X-ray crystallography, the microstructure of amorphous materials has rarely been explored due to a lack of high-resolution techniques capable of probing local molecular structures. Moreover, there is increasing interest in understanding the molecular nature of amorphous solids in pharmaceutical sciences due to the widespread utilization of amorphous active pharmaceutical ingredients (APIs) in pharmaceutical development for solubility and bioavailability enhancement. In this study, we explore multidimensional 13 C and 19 F magic angle spinning (MAS) NMR spectroscopy to study the molecular packing of amorphous posaconazole (POSA) in conjunction with the crystalline counterpart. Utilizing methods integrating homonuclear and heteronuclear 1 H, 13 C, and 19 F correlation spectroscopy and atomic 19 F-to- 13 C distance measurements, we identified the major differences in molecular packing between crystalline and amorphous POSA. The intermolecular "head-to-head" interaction along the molecule's major axis, as well as the "head-to-tail" molecular packing perpendicular to the major axis in POSA crystals, was recapitulated by MAS NMR. Furthermore, critical intermolecular distances in the crystal lattice were determined. Most importantly, the head-to-tail contact of two neighboring molecules was found to be preserved in amorphous POSA, suggesting localized molecular order, whereas crucial interactions for head-to-head packing are absent in the amorphous form resulting in long-range disorder. Our study, likely one of the first documented examples, provides molecular-level structural details to understand the molecular mechanism of crystalline-to-amorphous conversion of fluorine-containing drug substances occurring in drug processing and development and establish a high-resolution experimental protocol for investigating amorphous materials.

Two cases of angiomyolipoma of the kidney in middleaged Black women are described. This may be a more common cause of a renal mass than a carcinoma; it is important to distinguish between the two because of differences in management.

Autopsies were performed on 47 patients who died of Burkitt lymphoma in Uganda between 1967 and 1971. The patients were separated into four groups based on the duration of survival from the time of diagnosis. Twenty patients survived less than three weeks; all had massive tumors. Six patients died between 10 and 16 weeks after diagnosis, usually from side effects of drug therapy. Of 16 patients who died between 24 and 52 weeks after diagnosis, 13 showed involvement of the central nervous system. Five patients died one year or more after diagnosis; two had a late relapse following a disease-free interval of one and four years, respectively; the other three had survived with clinically apparent tumor that was not responsive to therapy. In recent years, there has been a steady reduction in the proportion of patients showing residual systemic involvement at autopsy. This reduction is balanced by an increase in the proportion of patients with lesions of the central nervous system.

Sixteen out of 48 adult African patients with Kaposi sarcoma were found to have tumour tissue in lymph nodes. The evidence suggests that there are probably two main types of involvement. One occurs predominantly in younger patients and involves many groups of glands, probably develops in situ, and is associated with a poor prognosis. The other form is the result of metastasis to a node from an aggressive tumour in the neighbourhood. This occurs more commonly in the older patient and carries a much better prognosis than in those with generalised lymphadenopathy, though worse than in patients with nodular disease without gland involvement. Follow-up over a period of many years will be required to discover the outcome in these cases. Kaposi sarcoma is unusual in women but when it occurs runs a more aggressive course than in men.

Five cases of fatal generalized herpes simplex infection in malnourished children are described. This is almost certainly a much more common disease in underdeveloped communities than is at present appreciated. Only a greater awareness of the disease, coupled with full use of histological and cultural methods of diagnosis, will lead to knowledge of its true frequency.A case of neonatal infection, the first recorded in an African, is also described. Reasons are suggested as to why this disease should be seen in malnourished infants in Africa but only very rarely in neonates.

The necropsy findings in 36 Ugandan patients with Hodgkin's disease are presented. One third of the patients were under the age of 20 years. Most cases showed a lymphocyte depleted tumour pattern. Infective complications were extremely unusual, probably because of the short survival time. Treated patients showed a slightly higher incidence of infective disease than those untreated. Death was a result of widespread tumour which usually showed involvement of many lymph nodes and the liver and spleen.