A 12 m sediment core recovered from the south basin of Lake Turkana, northwestern Kenya, reveals four major diatom assemblages that span approximately 5450 to 1070 years BP based on AMS radiocarbon analyses. The oldest assemblage, Zone D (5450 to 4850 yr BP), is dominated by Melosira nyassensis and Stephanodiscus spp. and is interpreted to reflect higher lake levels, fresher water and more variable seasonal mixing of the water column than the modern lake. Melosira dominates the assemblage in Zone C (4850 to 3900 yr BP) with some Surirella engleri and Stephanodiscus. This assemblage indicates a continuation of relatively high lake levels and seasonal mixing of a stratified lake. The brief peak of Surirella, interpreted as benthic, suggests an episode of slightly lower lake level. Thalassiosira rudolfi and Surirella predominate since the beginning of Zone B (3900 to 1900 yr BP), reflecting a decrease in lake level and increase in water column salinity. Increasing dominance of Surirella in Zone A (1900 to 1070 yr BP) may suggest that the lake continued to decrease in depth. Salinity probably rose to levels comparable with the modern lake. These results are consistent with paleoclimatic interpretations based on carbonate abundance, lamination thickness, oxygen isotope and bulk geochemistry profiles from this core and cores recovered from the north basin. It extends the known paleolimnology beyond 4000 yr BP of the earlier research to 5450 yr BP and into the early to mid Holocene pluvial phase in northern intertropical east Africa.

A 41-year-old man with human immunodeficiency virus (HIV) infection was admitted with dyspnea on exertion and a nonproductive cough. He was successfully treated for pneumocystis jirovecii pneumonia. Admission physical examination revealed stigmata of four HIV-associated infections demonstrated in the two clinical images: 1) scarring from herpes zoster in the right ophthalmic (V1) distribution of the trigeminal nerve (Panel A, hollow arrow); 2) seborrheic dermatitis in the bilateral nasal folds (Panel A, asterisk); 3) oropharyngeal candidiasis (Panel B, arrow); and 4) oral hairy leukoplakia (OHL; Panel B, arrowhead).Dermatologic manifestations are common among patients with HIV and may provide a clinical indication of underlying immune status. Herpes zoster and seborrheic dermatitis tend to occur early in HIV infection and are associated with relatively high mean CD 4 cell counts (380/mm 3 and 450/ mm 3 , respectively) 1 . Oral candidiasis, the most common oral opportunistic infection in patients with HIV/AIDS, often presents at CD 4 cell counts less than 300/mm 3 2 . OHL is relatively specific for HIV infection and is highly predictive of the development of acquired immune deficiency syndrome (AIDS) 3 . It is associated with a mean CD 4 cell count of 143/mm 3 4 . The presence of both oral candidiasis and OHL together suggest more severe immune dysfunction; these concomitant infections are associated with a mean CD 4 cell count of 89/mm 3 5 . In one study, the joint occurrence of any two HIV-related oral lesions had a mean CD 4 cell count of 123/mm 3 and a 75% positive predictive value of finding a CD 4 cell count less than 200/mm 3 4 . Our patient had a CD 4 cell count of 32/mm 3 .

A 77-year-old woman with hypothyroidism presented with a 2-week history of head, neck, jaw, and tongue pain. She had also developed slurred speech and difficulty chewing. On examination she had a temperature of 38.0°C. She was without neurological deficits. However, she did have difficulty protruding her tongue, which had a cyanotic appearance and was painful. Laboratory findings showed an erythrocyte sedimentation rate of 68 mm/hr. Temporal arteritis was suspected, and the patient was started on corticosteroids. A subsequent temporal artery biopsy revealed inflammation and thrombus formation consistent with temporal arteritis. On hospital day 3, she developed unilateral ischemia in her tongue, which eventually became necrotic (Fig.

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