The quaternary cuban platyrrhine Paralouatta varonai and the origin of Antillean monkeys.

We describe recently recovered dental and mandibular remains of the Cuban platyrrhine Paralouatta varonai, previously known from the holotype only (a nearly complete skull with very worn teeth). We also expand on the original description of the type specimen. Paralouatta is one of three extinct taxa of Greater Antillean Quaternary monkeys known from craniodental remains. The other two, Xenothrix mcgregori and Antillothrix bernensis, occurred in Jamaica and Hispaniola, respectively. It has been common practice to assume that Antillean monkeys were more closely related to individual mainland taxa than to each other. Thus, P. varonai was thought to be related to Alouatta; Antillothrix bernensis to Saimiri or Cebus; and X. mcgregori to Callicebus, or to callitrichines, or even to be of unknown affinity. With the discovery of well-preserved dental remains of Paralouatta, it can now be ascertained that this species was in fact very different from Alouatta. Cladistic analysis reveals a sister-group relationship between Antillothrix and Paralouatta, followed on the cladogram by Xenothrix and Callicebus (last taxon being the closest mainlaind relative of the Antillean clade). This conclusion has an important biogeographic implication: recognition of an Antillean clade, as advocated here, assumes only one primate colonization from the South American mainland, not several as previously believed.

Platyrrhine systematics: a simultaneous analysis of molecular and morphological data.

Platyrrhine phylogeny has been investigated repeatedly with morphological characters and DNA nuclear gene sequences, with partially inconsistent results. Given the finding in the past decade that the mitochondrial genome is a potentially valuable source of phylogenetic information, we gathered DNA sequence data of a fragment of the 16S and the entire 12S mitochondrial genes. The objectives were to generate a cladistic phylogeny based on these data and to combine them in a simultaneous analysis with morphological characters and preexisting nuclear DNA sequences. Mitochondrial data analyzed on its own yielded a cladogram that was different from those generated with other data sets. The simultaneous analysis of mitochondrial, nuclear, and morphological data yielded a tree most congruent with that generated with nuclear data and to a lesser degree with the morphological one. It depicted a basal dichotomy that led to two major clades: one of them comprised [Atelinae (Callicebus + Pitheciini)] and the other major clade comprised [Aotus ((Cebus, Saimiri) (Callitrichinae))]. The weakest point of the phylogeny was the position of Aotus as basal within their clade as opposed to more closely linked with either the callitrichines or Cebus-Saimiri. Relationships within callitrichines and atelines were unstable as well. The simultaneous phylogenetic analysis of all data sets revealed congruent signal in all of them that was partially obscured in the separate analyses.

Epipubic bones in eutherian mammals from the late Cretaceous of Mongolia.

An important transformation in the evolution of mammals was the loss of the epipubic bones. These are elements projecting anteriorly from the pelvic girdle into the abdominal region in a variety of Mesozoic mammals, related tritylodonts, marsupials and monotremes but not in living eutherian (placental) mammals. Here we describe a new eutherian from the Late Cretaceous period of Mongolia, and report the first record of epipubic bones in two distinct eutherian lineages. The presence of epipubic bones and other primitive features suggests that these groups occupy a basal position in the Eutheria. It has been argued that the epipubic bones support the pouch in living mammals, but epipubic bones have since been related to locomotion and suspension of the litter mass of several attached, lactating offspring. The loss of the epipubic bones in eutherians can be related to the evolution of prolonged gestation, which would not require prolonged external attachment of altricial young. Thus the occurrence of epipubic bones in two Cretaceous eutherians suggests that the dramatic modifications connected with typical placental reproduction may have been later events in the evolution of the Eutheria.

Systematics of New World monkeys (Platyrrhini, Primates) based on 16S mitochondrial DNA sequences: a comparative analysis of different weighting methods in cladistic analysis.

In order to investigate the effects of different weighting methods on a phylogeny reconstruction based on DNA sequences and to evaluate the phylogenetic information content of various secondary structures, a fragment of the large ribosomal mitochondrial gene (16S) was sequenced from 13 species of New World monkeys, three species of catarrhines, and Tarsius. The data were analyzed cladistically without weighting characters or changes, and with different weighting methods: a priori differential weights for transitions and transversions, two variants of dynamic weighting for each kind and direction of change, and successive approximations, using both the character consistency index (CI) and the rescaled consistency index (RC). The results were compared with published trees constructed from nuclear sequences of E-globins and morphological characters by different authors. The result of the analysis of the mtDNA data set with successive approximations, using the RC as weighting function, was the closest to the topology on which all molecular and morphological trees concur. Other relationships were unique to this tree. "Loops" were the type of secondary structure that showed maximum variation in sequence length and sites with the lowest character CI and RC. A large number of sites within loops showed high values for these indices, however, which suggests that uniform downweighting of these regions represents a large loss of phylogenetic information. Successive weighting, which assigns a weight for each particular character, seems to be a desirable alternative to this practice. We propose a new variant of dynamic weighting, which we call homoplasy-correcting dynamic weighting, that like dynamic weighting, is applicable to any kind of sequence, coding or noncoding.

Colonic diverticulitis-related exuberant granulomatous reaction in a patient with sarcoidosis.

A patient with long-standing sarcoidosis underwent partial colectomy for diverticular disease. Whereas sarcoid granulomas were rare in the otherwise normal colonic mucosa, an unusually large number of granulomas were scattered within the chronically inflamed peridiverticular tissues. It is suggested that in the framework of the sarcoidotic background, activated macrophages, being nonspecifically attracted to areas of inflammation, elicit an exuberant sarcoid granulomatous response. Our observation represents a previously undescribed variant of the "homing" phenomenon in sarcoidosis, unrelated insults inducing formation of granulomas in overabundance.

A lumbar hernia presenting as an obstructing lesion of the colon.

A patient with a lumbar hernia of Petit, presenting as an obstructing lesion of the ascending colon and concomitant acute cholecystitis is described. The anatomy, cause, and surgical treatment of lumbar hernia are reviewed.

Spontaneous colosplenic fistula complicating immunoblastic lymphoma.

Immunoblastic lymphoma of the colon, complicated by colosplenic fistulization, is reported. It is suggested that ulceration and extensive coagulative necrosis of a bulky large cell lymphoma in the absence of a desmoplastic reaction are the prerequisites for fistula formation.

The use of gallium-67 liver imaging for the early diagnosis of Budd-Chiari syndrome.

A gallium-67 study, performed in a rare case of Budd-Chiari syndrome (BCS) in a 6-yr-old child, showed marked concentration of the tracer in the left and caudate lobes of the liver. Ten days later, a less specific and clear-cut appearance of left- and caudate-lobe concentration of Tc-99m phytate was obtained. The possible use of Ga-67 citrate imaging to diagnose BCS in its earliest stage is suggested, although no firm conclusion can be made from this single case.

Cancer of the colon: a study of age-related incidence.

Incidence of colorectal cancer in Israel was studied in 1035 patients who were divided by ethno-geography into a Euro-American group and an Afro-Asian group. The majority of patients were in the age groups over 50 years, with a markedly higher incidence rate of disease in the Euro-American group. In the younger age group the incidence rate of the disease was significantly higher in the Afro-Asian group. These findings, if verified by others, must lead to revision of our present concepts of epidemiology of colorectal cancer.

Osteomyelitis of the maxilla in the newborn.

A case of osteomyelitis of the maxilla in a healthy infant is presented, the etiology of which seems to have been an upper respiratory tract infection. There was no evidence of lowered resistance and immunologic studies did not reveal any abnormality. Lincomycin seems to be the antibiotic drug of choice. In the present case, it was used, effectively, in conjunction with other antibiotics and surgical drainage.

Colonic anastomosis-a new approach: preliminary report.

The exact incidence of colonic anastomotic breakdown is difficult to assess. The low incidence reported on the basis of clinical observation only is misleading, since it has been demonstrated that leakages occur without clinical manifestation. Better evaluation of the rate of incidence will require meticulous postoperative investigation, as shown by Goligher. A new colonic anastomosis was performed in 24 cases of high and low anterior resections. The principal of forming a seromuscular cuff has been employed. The encouraging results merit further trial.